Note: Descriptions are shown in the official language in which they were submitted.
03-Lo-4462
10~9139
A~ur~ s POLYESTER COATIN~ COMPOSITION
T~ield ~f The Invention
The present invention relates to coatlng compositions
for producing polymeric coatings on substrates, and more
particularly to aqueous based polymeric coating solutions
containin~ water soluble polyesters or polyesterimides,
or mixtures thereof, in admixture with orthoamic acid .
diamines. More specifically, the invention relates to a
coating composition, a process for producing coating composi~
tions of the foregoing character, a process of coating
substrates therewith, coatingsproduced thereby, and to
coated suhstrates. Coatings produced from the aqueous
based polymeric coating solutions find particular but not ~-
necessarily exclusive utility in applications requiring
electrical grade properties, including high thermal :
stability, dielectric strength and cut-through temperature,
are curable in conventional wire tower apparatus, and
are suitable for overcoating with materials such as N~}on. ~ ~
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03-~0-4462
1~85~139 ~ :
Background or The Invention
A wide variety of synthetic resins have been
developed for use as electrical insulating material,
particularly material which is satisfactory for use as
slot insulation in dynamoelectric machines and for use
as insulation for conductors which are to be employed
as magnet wires (insulated electrical conductors) in
electrical apparatus. It is well known that insulating
material which is to be employed for these purposes
must be able to withstand extremes of mechanical,
chemical, electrical and thermal stresses. Thus, wires
to be employed as coil windings in electrical apparatus
are generally assembled on automatic or semi-automatic
coil winding machines which, by their very nature, bend,
twist, stretch and compress the enameled wire in their
operation. After the coils are wound, it is common
practice to coat them with a varnish solution containing
solvents such as ketones, alcohols, phenols and
substituted phenols, aliphatic and aromatic hydrocarbons,
halogenated carbon compounds, and the like. Insulating ;~
coatings on magnet wire must be resistant to these solvents.
In order to conserve space in electrical apparatus,
it is essential that the individual turns which make up the
coils be maintained in close proxlmity to each other.
Because of the closeness of-the turns, and the fact that there
may be a large potential gradient between adjacent turns, it
1s necessary that the coating resins employed as wire
enamels have a high dielectric strength to prevent short -`~
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03-L0-1l Ll 62
10~139
circuiting between ad~acent coils. In operatlon of
electrical apparatus containing coiled wires, high
temperatures are often encountered and the enamels must
be able to withstand these high temperatures as well as
the mechanical stresses and vibrations encountered in
electrical apparatus so that the enamel coating does
not sorten or come off the wire.
It is also well known that the power output of
motors and generators can be increased a great deal by
increasing the current density in the magnet wires of
these machines. ~iowever, increasing the current density
through magnet wires is accompanied by an attendant rise .
in the operating temperature of the magnet wires. This
increased temperature has meant that conventional water based
organic enamels, particularly the economically attractive
polyester based resins, could not be used in high current -~
density windings because the higher operating temperatures
encountered caused deterioration or decomposition of the
enamel coating. ~`
In the past, many attempts have been made to
prepare magnet wires which met all of the mechanical,
chemical, electrical and thermal requirements of high~ ~
temperature magnet wire while still being economically .-
feasible. Cost per unit of power output of a resulting -~
dynamoelectric machine is a very important factor in any
.
magnet wire insulation, since an excessive magnet wire
cost tends to make a magnet wire impractical for use
regardless Or its properties. While excessive cost Or ~
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03-Lo-4462
1()89139
a magnet wire is generally the result Or five factors,
a sixth factor, that of ecology and environmental
considerationc in connection with the use of organic
solvents, is now Or prime importance.
Tlle first, and the most obvious, factor is the
cost of the raw materials in the resin which is to be
applied to t}le conductor. The second factor is related
to the ability Or the resinous material to be dissolved
in readily available, inexpensive solvents. Since
resinous materials are preferably stored and transported ~
in solution, the bulk and weight Or the solvent play a ~-
large part in the cost of having the resin at the place
where it is to be used at the time it is to be used. In
practice, it has been found that it is desirable to
employ resinous materials as wire enamels which are
capable of being held in solutions which contain at
least 30 to 50 percent, by weight, of solids. Sin¢e
the solvents in the resinous solution are generally allowéd
to escape without recovery from the wire coating operation,
the cost of the solvent is an important factor in the
.. . .
cost of the cured enamel.
The third factor which vitally affects the cost of -
an enameled wire is the time required to cure the enamel
once it has been applied to the conductor. If this time
is excessive, an unduly large baking oven is required or
` ~ the speed of the wire through the oven must be maintained
;~ at an uneconomically low rate. The fourth factor which
affects the cost of a magnet wire is the flexibility ~ ~
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03-r,0~ )2
- 1()89~39
of the condi~ions which may be employed in applying the
resin to the conductors and in curin~ the resin once it
has been applied. If the wire speed range in the curing
operation, the curing temperature, and the wire diameter
sizes are critical, it is obvious that a large amount -~
of defective magnet wire may be prepared under mass
production conditions; however, if lar~e variations in
curin~ conditions are tolerable, only a very small
amount of the magnet wire prepared need be discarded
because of defective insulation.
The fifth factor which is important in the cost
of a magnet wire is the ability of the same resinous
solution to be applied to both round and rectangular
conductors and to conductors made of various metals.
If different resin solutions must be used for each type~
of conductor, the time required to change the resin
solution is an inte~ral part of the magnet wire cost,
The sixth factor, which is important to the overall
~; production process, ae well as to the environment in whlch
the production takes place, is the ecological and polIution
factor, and the related safety and toxicity considerations.
Organic solvents are becoming increasingly valuable, and
production communities are becoming more concerned about the
quality of life and the environment surrounding the ~-
25 ~ manufacturing operation. Thus, it is highly important for
a variety of reasons to avoid discharging and wasting organic
solvents directly into the atmosphere. A related consideration
with respect to the use of organic solvents is therefore
the cost of handling and disposal. It has been established
30~ that for a typical organic solvent coating operation in a
conventional wire tower, more than 90% of the fuel bill is
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03-Lo-44 62
1089139
utllized to heat alr to dilute evapora~ed solvent and
thereby dilute it to a nonflamrnable state and to burn the off-
gases to CO2 and ll20 before they are emitted into the
atmosphere.
At the present time, commercially available coating
materials for use in electrical applications, such as the
coating materials disclosed in U.S. Patent No. 2,936,296,
issued May 10, 1960, to F.M. Precopio and P.W. Fox for
"Polyesters ~rom Terephthalic Acid, Ethylene Glycol and a
1~ Higher Polyfunctional Alcohol," and used and sold commercially
under the trademark "ALKANEX" by General Electric Company,
are widely used, highly successful and effective compositions,
but have the economic and ecological disadvantage of
requiring the use of organic solvents. Where organic
solvents are used, they are driven off during curing
of the coatin~,s and are generally not economically
recoverable. Many such solvents are becoming economically7
ecologically and environmentally prohi~itive, making it increasing~
ly d~sira~le to utilize substantially wat~r based solvents.
A wide variety of aqueous polyester coating solutions
are known in the art. With few exceptions, however, the ;-
coatings produced from such aqueous solutions are not
; suitable for electrical applications, particularly for
wire enamels. Polyester coatings from aqueous solutions -
~25 cure only very slowly to a tack-free state, exhibit
excessive weight loss on curing as compared to organic
solvent based resins, and, on aging, become brittle, darken,
lose flexibility and génerally depolymerize under the
. .
conditions of most electrical applications.
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03 r,o-4462
108~3139
.
Polyamide and polyimide coating materials in aqueous
solutiolls, and coatings produced therefrom, are generally
well kno~ln in the art, and are highly effective for
producing stable electrical grade coatings. See, for
example, U.S. Patent No. 3,65?,500, issued March 28, 1972,
to M.A. Peterson, for "Process For Producing Polyamide
Coating Materials By End Capping"; U.S. Patent No.
3,663,510, issued May 16, 1972, to M.A. Peterson, for
"Process For Producing Polyamide Coating Materials";
U.S. Patent No. 3,507,765, issued April 21, 1970, to
F.F. I~olub and M.A. Peterson, for "Method For
Electrocoating A Polyamide Acid"; U.S. Patent No.
3,179,614, issued April 20, 1965, to W.M. Edwards, for
"Polyamide Acids, Compositions Thereof, And Process For
Their Preparation"; U.S. Patent No. 3,179,634, issued
April 20, 1965, to W.M. Edwards, for "Aromatic
Polyimides And The Process For Preparing Them"-; and
U.S. Patent No. 3,190,856, issued June 22, 1965, to
!
E. Lavin, et al. for "Polyamides From Benzophenonetetracarboxylic
Acids And A Primary Diamine." The prior art involves
generally the preparation of a coating medium containing a
high molecular weight polyamide acid, and application of
the coating medium to a substrate to provide a polyamide ~
acid coating thereon, followed by the curing of the high ~-
molecular weight polyamide acid to a polyimide. ~hile such -
coating materials produce coatings having desirable
properties, particularly for electrical applications, they
are relatively more expensive than polyester type coating
materials.
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03-Lo-4462
1~il9139
Aqueous base polyamide acid systems, as described
in the above-mentioned patents to Peterson, result in
excellent high temperature, electrical grade coatings
(250C., 40,000 hr., insulation coatings), which are stable,
and easily made and used, but are relatively expensive
when compared to the polyester compositions. It should
be noted that the polyester (Alkane ~ ype) magnet wire
coating provides a thermal insulation barrier which, ~-
though it is less than that of polyimide magnet wire
coating, nevertheless is highly suitable for a large
...
segment of the magnet wire needs in the industry, particularly
for class B applications, (135C., 20,000 hr. coatings). ~ ~-
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03-I,0-4L162
1089139
A~ueous based acr~lic systems, of the type
descrlbe~ in U ~ Patent No. 2,787,~03, issued April 2,
1957, to P.~'. Sanders for 'IAqueous Coating Compositlons
and Suhstrates Coated Therewith," while inexpensive, are ; ~`
not generally suitable for high temperature electrical
grade coatinp,s applications such as class B applications.
Moreover, such aqueous based acrylic systems are
emulsions and not solutions, thereb~ creating certain
stability problems. ~ -~
Efforts have been made to mix various emulsion ~
polymerized resins to upgrade coatings produced therefrom. ~-
For example, properties of coatings and films from polyacryli~c
pol~ester resins in aqueous solvents have been somewhat improved
b~ the addition of water soluble phenol-formaldehyde resins,
epoxY resins and melamine resins. Such polymer blends, however,
are generally not sufficiently upgraded to the classical
:: .
polyester grade insulations presently utilized in the
magnet wire industry.
Recause of the high latent heat of vaporization of ~ ;
water, it is desirable in water based systems, particularly
for application as wire enamels, to utilize as high a
solidscontent as is possible, commensurate with workable
viscosities, when the medium is used with automatic
coating apparatus such as wire towers. Hi~h molecular
~25 weight polymers, such as the polyamide acid polymers which
::
-~ are described in the patents listed above, produce extremely
;-~ viscous solutions except in relatively low solids content
~ systems. For many applications, the low solids content
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1089139
s~stems are ~ulte suitable. For wire tower use, however,
the low solids content aqueous solution creates production
problems which reduces the efficiency of the tower.
Criteria for electrical insulating materials,
such as magnet wire insulations, slot insulations,
insulating varnishes and the like have been established
in the art. In order to determine whéther the insulation
on a magnet wire will withstand the mechanical, ;
chemical, electrical and thermal stresses encountered
in winding machines and electrical apparatus, it is
customary to apply the resin to a conductor, by a method
which will be described hereinafter, and to sub~ect the
enameled wire to a series of tests which have been
designed to measure the various properties of the enamel
on the wire.
Various tests, which will be described in detail
later, include the abrasion resistance tests, the 25 per-
cent elon~ation plus 3X flexlbility test, the snap elongation
test, the 70-30 solvent resistance test, the 50-50 solvent
resistance test, the dielectric stren~th tests, the
flexibility a~ter heat aging test, the heat shock test,
the cut-throu~h temperature test, and the high temperature
dielectric strength loss test. The enamel on a -
~; conductor which will withstand the mechanical, chemical ~ -and electrical stresses encountered in magnet wire ~ -
applications and which is operable at temperatures ~-
of at least 135C. for extended periods of time must
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03-I.0-44~2
lV89139
withstancl at least 10 strokes with the average o~ three
tests being not less than 20 in the repeated scrape abrasion
resistance test, must withstand 980 "grams to fail"
in the unidirectional scrape resistance test, must pass
the 25 percent elongation plus 3X flexibility test, must
show no surface defects in the snap test, must show no
attack on the insulation in either of the solvent resistance
tests, must have a dielectric strength of at least 1500 v.
per mil twisted pair, must show no surface defects when
wound on a 3X mandrel after heat aging for 100 hours at ~ '
175C., must show no defects when a 5X coil is aged for
30 minutes at 155C. in the heat shock test, and must
have a cut-through temperature of at least 215C. under
a 1000 gram load for 18 AWG heavy coated insulated magnet '
wire on copper conductor. In addition, for the same type
of ma~net wire with Nylon overcoat the insulated conductor
must not show a loss in dielectric strength of more than
' 2/3 of original dielectric strength or a minimum of 1500
volts per mil twisted pair, must show no surface defects
'20 when a 3X coil is aged for 30 minutes at 155C in the heat ~ '
shock test, and must have a'cut-through temperature of ~'
, .
at least 200C under a 1000 gram load. ;~--
The abrasion resistance tests, flexibility test,
and snap test are employed to determine the mechanical ~;~
properties of a magnet wire. Abrasion resistance is a
measure of the amount of abrasion an insulated electrical
~ conductor will withstand hefore the insulating enamel
:' ~ is worn away from the 'conductor. Repeated scrap abrasion -'
' ' resistance is measured by rubbing the side of a loaded
round steel needle back and forth across the surface of
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03~ 4462
108~3139
an insulclted electrical conductor until the enamel is
worn away. The number of strokes required to wear the
enamel a~Jay is referred to as the number of abrasion
resistance strokes. Unidirectional scraperesistance is
measured by rubbing the side of a round steel needle
across the surface of an insulated electrical conductor
under increasing load until the conductor is exposed.
The load required to expose the conductor is referred to
as the "grams-to-fail" load. For a complete descriptlon
of the procedure followed in abrasion resistance testing
where a needle is rubbed back and forth across the insulated
electrical conductor, reference is made to NEMA Standard
Section MW 24 which describes the procedure followed in
the present invention. This NEMA Standard is incorporated
by reference into the present application.
The flexibility of the enamel OD a magnet wire
is determined by stretching the enameled conductor and
examining the stretched portion of the wire under a
.
blnocular microscope at a magnification of ten to
determine if there are any imperfections on the surface
. .
; of the enamel. The imperfections which may be noted on --
the surface of the enamel are a series of parallel surface
lines of fissures which are perpendicular to the long
- ~ axis of the wire. This condition of the enamel film is ;~
.
known as ¢razing. Another defect which can sometimes be
observed is a break in the enamel film in which the two
sections of the film are actually physically separated and
the opening extends in depth to the exposed conductor. This
defect is called a crack. A third defect which may be noted ;
is a mar or blemish in the enamel film.
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03~ 4462
10~39139
In the 25 percent elongation plus 3X flexibility
test an insulated electrical conductor having a diameter
X is elongated 25 percent and wound about a mandrel having
a diameter 3X. If examination of the enamel under a magnifi-
cation of ten shows none of the surface defects noted above,
the insulation on the conductor passes this flexibility test.
In some of the examples which follow, flexibility tests using
elongations other than 25 percent and mandrels having a diameter
other than 3X are employed. However, in all of these cases
the flexibility test is as severe as the 25 percent elongation~
plus 3X flexibility test.
The snap elongation test measures the ability of
the insulation to withstand a sudden stretch to the breaking
point of the conductor. The insulation on the conductor must
not show any cracks or tubing beyond three test wire diameters
on each side of the fracture after the insulated conductor
is ~erked to the breaking point at the rate of 12 to 16 feet
per second. ;
; Solvent resistance tests are conducted to determine~
~20~ whether a magnet wire will satisfactorily withstand the
chemical stresses found in electrical applications, i.e., ~ `
whether the enamel is resistant to the solvents commonly
; employed in varnishes which may be used as an overcoat for
the enameled wires. The solvent resistance test is the
~25 ~ determination of the physical appearance of an enameled wlre ~-
after immersion in a refluxing bath of a specified solution.
Two solution systems are used for each sample of wire. Both
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of these solutions contain a-mixture of alcohol and toluene.
~ The alcoholic portion is composed of lO0 parts by volume of
!i~30 U.S.P. ethanol and 5 parts by volume of C.P. methanol.
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108~13~
One solvellt test solution (which is designated as 50-50)
consists Or equal parts by volume of the above alcohol
mixture and of toluene. The second solution (which is
designated as 70-30) is 70 parts of the alcohol mixture and
30 parts of toluene.
In the usual operation of the test, about 250 ml.
of the solution is placed in a 500 ml. round-bottomed,
sin~le-necked flask which is heated by a suitable
electrical heating mantle. A reflux condenser is attached
to the flaslc and the solution is maintained at reflux
temperature. A sample is formed so that three or more
straight lengths of the wire having cut ends can be
inserted through the condenser into the boiling solvent.
After five minutes the wire is removed and examined for ~ ~-
blisters, swelling or softening. Any visible change
in the surface constitutes a failure. Soft (requiring ~
the thumbnail to remove it) but smooth and adherent ~ '
. ,
enamel is considered to pass this five minutes-test. ~ -
The samples are then returned to the solvent for another
five minutes and re-examined for the same defects. If
the enamel shows any blisters or swelling at the end of ~ :
either the five minutes or the ten minutes test in the
70-30 solution (the 70-30 solvent resistance test) the ~-'
enamel has failed the solvent resistance test. If the
enamel shows any blisters or swelling at the end of the
five minutes test in the 50-50 mixture (the 50-50 solvent ~-
resistance test) the enamel has failed this solvent
resistance test. .
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03-Lo-4462
10t~91~9
Thc~ dielectric strength Or the enamel film determine-s
whether the insulation on a magnet wire can withstand the
electrical stresses encountered in electrical apparatus.
The dielectric strength of an insulating film is the
volta~e required to pass a finite current through the film.
In general, dielectric strength is measured by increasing
the potential across the insulating film at a rate of
500 volts per second and taking the root mean square of
the voltage at which the finite current flows through the
film as the dielectric strength.
The'type of specimen employed to measure
dielectric strength is a sample made up of two pieces of
enameled wire which have been twisted together a
specified number of times while held under a specific
tension. A po;;tential is then placed across the two
conductors and the voltage is increased at the rate of
500 volts per second until a finite current flows through
the insulation. The voltage determined by this method
is referred to as "dielectric strength, volts (or volts ~' '
per mil), twisted pair." The number of twlsts and the ~'--
tension applled to the twisted wire is determined by
; the size of the bare conductor. A complete listin~ of the
specifications for various wire sizes are described in
the aforementioned NEMA Standard Section MW 24.
In order to determine whether a magnet wire may be
employed at high temperatures, it is necessary to measure
properties of the enameled conductor at high temperatures.
Among the properties which must be measured are the cut-
through temperature of the enamel, the flexibility of the
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03-L0-41l62
1089~39
enamel a~tel h~at aging at an elevated temperature,
the heat shock characteristics Or the enamel, and the
dielectric strength loss Or the enamel when heated at
high temperatures in air. Since it is well known that
copper is the most common conductor, all of the thermal
; tests Or magnet wire are conducted on copper magnet wire.
The cut-through temperature of the enamel film is
measured to determlne whether the insulation on a magnet
wire will flow when the wire is raised to an elevated
temperature under compressive stress. The cut-through
.
temperature is the temperature at which the enamel film
separating two magnet wires, crossed at 90 degrees and .
supporting a given load on the upper wire, flows sufficiently
to establish electrical contact between the two conductors.
Since magnet wires in electrical apparatus may be under
compression, it is important that the wires be resistant
to softening by high temperature so as to prevent short ~ ;
circuits within the apparatus. The tests are conducted
by placing two eight inch lengths of enameled wire
perpendicular to each other under a load of 1000 grams "
at the intersection of the two wires. A potential
of 110 volts A.C. is applied to the end of each wire and
.~ . .a circuit which contains a suitable indicator such as a line
recorder, a buzzer or neon lamp is established between the ~ ;
ends of the wires. The temperature of the crossed wires and
; the load is then increased at the rate Or 3 degrees per minuteuntil the enamel softens sufficiently so that the bare
conductors come into-contact with each other and cause the
indicator to signal a failure. The tem~erature at which
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03-L~-4462
1089139
this cir~uit is established is measured by a thermocouple
extenclin~ into a thermo~rell to a point directly
under the crossed wires. The cut-through temperature
is taken as the temperature in the thermowell at the
moment when the current first flows through the crossed
wires. Although this temperature is always somewhat lower
than the true temperature of the wires, it gives a fairly
accurate measurement of the cut-through temperature range of
the enameled wire being tested. Magnet wires designated for
operating temperatures of at least 135C. should have a
cut-through temperature of at least 175C. ;
When measuring properties of an insulating film
such as percent elongation after heat aging, heat shock,
weight loss after heating in vacuum, and dielectric
strength loss after heating in air, what is actually being
measured is the effect of thermal degradation of the
enamel on the particular properties belng measured. The
most straightforward method of measuring this thermal
degradat1on of an enamel on a wire is to maintain the
enameled wire at the temperature at which it is desired
:~ '
to operate the wire until decomposition takes place. ~ -
However, this method is impractical in the evaluation oi
~; new materials because of the relatively long periods of ;~
time involved. Thus, it might be found that an enameled ~ -~
wire may operate successfully at a temperature of 135C.,
for example, for five to ten years beIore any substantial ~
thermal degradation takes place. Because it is obviously ~ -
impractical to wait such a long period of time to find
out whether a resin is satisfactory for magnet wire
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03-Lo-4462
~)8~139
enamel, it is customary to conduct accelerated heat life
tests on these enarneled wires. Since thermodynamic theories
show that the rate Or a given reætion can be determined
as a function Or temperature, it is possible to select
elevated temperatures for thermal tests of enamel films
and to calculate the thermal properties of the enameled
wire at the desired operating temperature from these
accelerated test data. Although it might be expected that ,
degradation reactions which occur at elevated test
temperatures might not occur at temperatures at which the
magnet wire is to be operated because of activation
; energies required to initiate certain reactions, ,~
,~ experience has shown that accelerated heat life testsare
, an accurate metho~ for determining the heat life of a, ;~ ,
' 15 material at operating temperatures. -~-
In determining whether an enamel film will lose ~ ,~
its flexibility after extended periods of time at
~; , operating temperature, it is customary to heat age a
,sample of the enameled wire. In practice it has been found~
20, that for a magnet wire to be satisfactory for use in
~ dynamoelectric machines at temperatures of at least 135C. -
;~ a sample of the enameled wire having a conductor diameter X
must show no surface defects when wound on a mandrel having , ~'~
a diameter Or 3X after heat aging for 100 hours in a circulating
air oven maintained at a temperature of 175C.
The effect of high temperatures on the flexibllity '~"
of a magnet wire enamel may also be measured by winding a
sample of the enameled wire having a conductor diameter X '~
on a mandrel having a diameter of 5X, removing the sample of
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03_r,0-4462
10~9139
wire from the mandrel and placing it in a circulating air
oven maintained at 155C. After 30 minutes the sample of
wire should show no surface defects in any of the windings
in order ~or the enameled wire to have sufficient flexibility
for steady operation at least 135C. This test is known
as the heat shoclc test.
The final thermal requirement of a magnet wire
which is to be used at elevated temperatures is that the
dielectric strength of the enamel film remains sufficiently
high at elevated temperatures after a long period of
operation so that no short circuits occur between ad,jacent '
magnet wires. We have found that for a magnet wire to be ;,
satisfactory for operation,at a temperature of at least ~' '
135C. its dielectric strength should not be less than
two-thirds of the initial dielectric strength after being
maintained at a temperature of 175C. for 100 hours in an oven ; ,'
circulating air having a relative humidity of 25 percent at
room temperature. This change in dielectric stren~th is
measured as the dielectric strength, volts (or volts per
mil) twisted pairs, b'oth before and after the 175C.
heat aging.
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03-Lt)-41162
1089139
Objects Of The Invention
It is the principal obJect of the present invention
to produce a coating composition which is highly aqueous : -
in solvent composition, is low in cost, may be utilized
in existing commercial coating equipment, and which produces
coatings suitable for severe, heavy duty application, -~
particularly electrical uses such as wire enamels and the
like.
More specifically, it is the objective of the
present invention to provide a resin system findlng
particular but not exclusive utility in magnet wire ~ :
enamel formulations, which is commercially competitive
with existing magnet wire compositions, which is highly
aqueous thereby eliminating organic solvent disposal, :
, . . . .
toxicity and combustion problems, and which reduces or
eliminates pollution problems, and is thus an ecologically ;~
and environmentally positive system. . ~
Another object of the present invention is to : ;
enable the utilization of water soluble polyester resins .
for applications such as electrical insuIation and magnet
wire application, and more particularly to upgrade aqueous
polyester resin containing systems to produce electrical .
. . .
grade coatings which are thermally stable and which have -
~ improved mechanical and chemical properties. . ~
; ~: 25 A further object of the present invention is to
::
provlde a stable, economical, highly water soluble resin .
system suitable for use in a wide variety of coating ::~
applications including electrical coating applications '
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03-Lo-4462
1~)89139
such as magnet wire enamels.
~till a further object is to provide a water
soluble resin system for coating applications, which
resln system produces coatings which on curing, are
clear, tough, flexible, dielectric and heat stable.
Another ob;ect is to provide a water based coating
medium of the foregoing character, which is suitable for
use in existing conventional coating equipment, including
conventional wire towers for coating continuous filament
materials such as magnet wire.
A more detailed object of the present invention is
to provide an aqueous based coating medium of the foregoing
characteristics from which a resin coating can be
applied to a substrate and which when so applied is
- 15 readily cured to a tack-free state, evidences a minium -
weight loss on cure, and does not darken, lose its
; flexibility or depolymerize on aging.
,,'; '': ''~' '".
' ~
: ~ ~ '" , ~' .
'
-21-
': ~ , ` . , , ~ ; ,,. : ,
o3-Lo-4462
~089139
~Summarv O~ ~he Inventlon
In accordance with the foregoing obJects, the
present invention contemplates a coating composition
havin~ a substantially aqueous base and embodying in
admixture, a water soluble polyester coating resin and
a low molecular wei~ht orthoamic acid diamine produced
as the reaction product of an aromatic diamine and an
aromatic dianhydride in the molar ratio of m/(m-l)
respectively where m has a value of from 2 to about 7. -
The polyester and orthoamic acid diamine are admixed -
in the ratio of from 1 to 10 parts polyester and from
1 to 10 parts orthoamic acid diamine. Additional in~redients
may be added including accelerators as well as minor amounts
of water soluble resins such as phenol-formaldehyde resins,
aminoplasts, epoxy resins and the like.
The polyester resins are conventional commercially ~-
available water soluble polyester resins conventionally -
.
- used in coating operations, while the orthoamic acid diamine
is produced as the reaction product of an aromatic diamine
and an aromatic dianhydride. In the latter process, the
diamine is first dissolved in an appropriate solvent and
the dianhydride is then slowly added to form an orthoamic
acid diamine reaction produc-t in the solvent system. Where
the molar ratio of aromatic diamine to aromatic dianhydride
is two-to-one, the reaction product is a-diamide diacid
diamine. ~To provide an aqueous base diamine system,~the
reaction product, in the water-miscible or~anic solvent
- system, is reacted with a volatile base such as ammonia or
primary or secondary amine, to produce a water soluble compound. ~ ~;
'~
: ~ ,,
~:
-22-
.,.:: , , . , . , , :............. .
03-Lo-4462
108~139
Water is then aAded to provide an essentially aqueous
based solution which may be mixed with an aqueous
solution of a polyester resin.
Upon application Or a coating of the solution to
a substrate, such as magnet wire, the coating may be
cured at a temperature between 100 and 500C. to drive off '
the water and solvent and copol,vmerize the polyester and
orthoamic acid diamine. The result is a clear, flexible,
tough, adherent, solvent resistant dielectric thermally ,stable ~ '
polymeric coating. Unexpectedly, the coating film thus
produced exhibits the foregoin~ properties even when the
polyester resin constitutes the ma(jor portion of the solids.
The resultant coatings exhibit properties comparable to
coatings achieved from conventional magnet wire polyester - ;- '
resins applied from organic systems. The aqueous based, ;~,
coatin~ medium of the present invention is stable and '
neither ~ells nor coa~ulates nor forms a precipitate on
standln~3 and has the advanta~es attributable to an aqueous '` '
base system as contrasted to an organic solvent based system
insofar as the environment, ecolo~ical and poIlution factors '
are concerned. The surprising result is that coatings produced
-
~ from aqueous polyester resin containing media are up~raded
~ . ,
with respect to physical properties comparable to like properties
achieved from present commercial coating materials.~ ;~
,
! - 23
03-Lo-4462
19139
Descr:lr)tion of the Preferred Embodiment
The coating compositlon of the present invention
is formed by the admixture, in water or a highly
aqueous solvent, of a water soluble polyester or
polyestermide resin with an aromatic orthoamic acid
diamine, particularly an aromatic diamide diacid diamine. ~ -
Additional water soluble resin materials, such as phenol-
formaldehyde resins, epoxy resins, and aminoplasts, may
be added to the mixture. The water soluble polyesters, -
polyesterimides, phenol-formaldehyde resins, epoxy resins
and aminoplasts are all widely known materials which are
readily available in the commercial market. The aromatic ;
orthoamic acid diamine, such as the aromatic diamide-
diacid-diamine, is an o~ gomericmaterial produced by ;~
reacting an aromatic diamine and an aromatic dianhydrlde -~
` in the molar ratio from two-to-one, respectively, to about
seven-to-six, respectively, with the former generally in
the amount of one mole greater than the latter. Such ,~ -
compounds, containing a one mole excess of the diamlne,
~20 are low molecular weight, essentially monomeric compounds
as distingulshed from high molecular weight polymerlc
compounds, and may be generally expressed by the formula X(YXjnYX
where X represents an aromatic diamine, Y represents an
aromatic dianhydride, and n has a value of from O to 5.
Defined another way, the orthoamic acid diamines referred ;
to~are the reactlon product of m-moles of an aromatic diamine
and (m-l) moles of an aromatic dianhydride where m has a
va:ue of from 2 to about 7, and a preferred value of from ~ ~-
.
o3-Lo-44 G2
1~)89~39 : ~
2 to 5. Aromatic diamide-diacid-diamines and the manner
of making and using them as coating materials to produce
coatings and coate~ substrates are described in detail in
~C ~ rra~ 7~
copending application Serial No. ~7" l183, filed Ju~c 3, 1~7'1,
by Marvin A Peterson, for Coating Composition and Method
of Coating Substrates Therewith, and assigned to the same
assignee as the present invention. The higher molecular
weight aromatic orthoamic acid diamines produced by reacting
the diamine and dianhydride in molar ratios defined above
are nevertheless generally characterized as "low molecular
weight" monomeric materials and are produced in substantially -
the same manner as described in application Serial No. 47" 4~3. -
These monomerics should be distinguished from the polymeric
high molecular weight polyorthoamic acids disclosed in
U.S. Pat. No. 3,652,500, issued Mar. 28, 1972, to
M. A. Peterson for "Process for Producing Polyamide Coating
Materials by Endcapping" and U.S. Pat No. 3,663,510, issued
May 16, 1972, to M. A. Peterson for "Process for Producing
Polyamide Coating Materials."
All of the above materials are mutually soluble in
water or highly aqueous solvents, and are compatible with
each other in solution. As the molecular weight of the
.
orthoamic acid diamine increases (n ~20), however, the --~
compatibility of the diamine with the other water soluble
polymers decreases rapidly, to the end that water soluble
polyorthoamic acid polymers, as described in Pat. Mo.
3,652,500 and Pat. No. 3,663,510 are incompatible with
other water soluble poly~ers such as polyesters. Accordingly,
.: .
.
~ "'
- 25 -
03-Lo-4 4 62
108'3139
it has heretofore proven impossible to prepare a stable, ~ :
homogeneous coating medium which incorporates both
water soluble polyester or polyesterimide resins and :
water soluble polyorthoamic acid resins. ~:.
'' .' `:
~ ~ ' ' , ;
~: ' :
"~ ~.. -
:
, ~, .-~ . ~ : : :
~. . ."~' ' ~
. ~ . . ..
: . . ~
-26-
: .. . . . . .. . . .. .
03-L0-4462
1089139
Polyester Resin
A wide variety of water soluble polyester resins
find application in connection with the present invention.
It has been ascertained that the base polymers which present
the requisite thermal stability for use in connection with -
the present invention are of the polyester genus, and are
generally formed from aromatic anhydrides and acids, such as
trimellitic anhydride and acid and phthalic anhydrides and
acids. Extensive developments have been made in the field of
water solub~e polyesters for coatings, and many such materials
are in widespread use in the form of pigmented, but otherwise
quite clear, highly aqueous solvent systems. While such
polyester resins are readily available as commercial products,
their exact formulation is most often a proprietary matter
with the particular manufacturer. It is possible, however, as `
demonstrated in the following examples, to formulate and
prepare a wide variety of such polyester resins from known
materials by following known procedures.
The polyester resins are condensation products ~
of a polycarboxylic acid and a polyhydric alcohol. To achieye ~; ;;
the desired thermal stability, the preferred polycarboxylic
acid is an aromatic acid or anhydride. The condensation -
product desirably has an acid number of at least 45, and
generally between about 45 and 80. Among the useful polyester
resins are the polyesters produced as the reaction product of
; such aromatic anhydriaes and acids as trimellitic anhydride,
-27-
1089139 o 3-Lo-4462
phthalic aci~, phth~lic an~ydri~e, terephthalic acid, isophthalic
acid, and certaln diacid reaction products such as the reaction
product of 2 moles of trimellitic anhydride and 1 mole of
4,4'-methylene dianiline, thus:
H0 C ~ >N~ ~H2
together with such aliphatic diacids as adipic acid; and such
polyhydric alcohols as propylene glycol, neopentyl glycol, butylene
glycol, diethylene glycol, trishydroxyethylisocyanurate, and thè
like.
Polyester resins and aqueous solutions thereof useful
in this invention are selected from a wide variety of polyester
resins which generally produce coating films having good impact -
resistance and hardness, are flexible and adherent to substrates to
which they are applied and can be applled from both organic and -
aqueous solvent systems. Such polyesters will have an acid number
in excess of 45 and generally between 45 and 80 and posslbly higher.
Below 45 gellation may result. The polyesters are highly stab~1é~
and maintain their clarity and color over a long period of time.
. :~
In the selection of polyester resins for appIication to
:: . ,
magnet wire from aqueous solutions, the use of sucb materials in ;~
~25 commercial wire towers must be considered. Coating resins utilized
:
in such towers~must be curable at the wire speed, usually between `
` 40 and 60 feet per minute, and particularly at wire speeds of 50-55
feet per minu~te, and at the temperatures prevailing in the tower.
Among other factors, polyester resins to be applied from aqueous
solutions will~desirably have a hydroxyl value in the range of from
~:
.
-28-
~: ' '' ' ' '' ' , ' -
03-LO-4462
10~39139
about 100 to about 200 and preferably between about 110 and about
160. Also, such polyester resins, in consideration of electrical
applications, will have an aromatic to aliphatic ratio of 22 to 40
molar percent. In admixture with the orthoamic acid diamines
hereinafter described, the aqueous coating solutions will desirably
have an aromatic to aliphatic molar ratio of from about 25 to about
50 percent. The above criteria can be utilized to select appropriate ~ ~ ^
reactants for producing the polyester resins as well as the admixture
of the polyester resins with the orthoamic acid diamines. In this
manner coating solutions suitable for application by selected
procedures, such as commercial wire towers can ba readily formulated.
Appropriate accelerators or catalysts may be added to the
polyester resin system. Appropriate catalysts for the polyester ~
resins are certain organometallic compounds such as the titanium ~ ;
chelates. These titanium chelates are commercially available from
E. I. duPont de Nemours & Co. as Tyzor~ OG tetraoctylene glycol "',!'~
titinate, Tyzor TE triethanolamine titinate, and Tyzor LA ammonium ~ -
salt of titanium lactate, as well as from other commercial sources.
As shown in the examples, the accelerators or catalysts improve the
cure of the coating compositions containing polyester resins and the
orthoamic acid diamines without adversely affecting the properties
of the cured films.
The number and variety of water reducible or soluble
polyester resins with the above characteristics and properties is
~`25 substantially unlimited. While examples are presented showing the
preparation and use of a variety of polyester resins, it is not ~-
intended to either limit this disclosure or to show how many kinds
of polyesters can be prepared. It is rather intended to demonstrate ~
that the present invention involves the surprising and unexpected ~` ;
discovery that, by the admixture of a water soluble polyester resin ~ ~
.
. . .
29 `
..
03-LO-4462
10~ 9
and a water soluble orthoamic acid diamine, electrical grade,
thermally stable coatings may be produced.
Water soluble polyester resins by themselves, generally
speaking, do not have the requisite properties for application
from aqueous solutions to form electrical grade coatings, particular-
ly wire enamels. Efforts have been made to upgrade water reducible
polyester resins by the addition thereto of such known electrical
grade water reducible resins as the polyamide acids. These two ~
resins, though both water soluble, have been found to be incompatible, - ~ `
and in admixture result in or separate into both a polyester rich
layer and a polyamide acid rich layer.
While other resins, such as phenol-formaldehyde resins,
epoxy resins, and the like may be blended in water soluble form,
with water soluble polyester resins, the results are less than
satisfactory as far as electrical properties are concerned, although
many of the properties of coatings produced from the combined
polymers show improvement over the properties achieved from coatings - ;~
:~
of the individual polymers.
,'
'~
':~
'~, ': '
~:
- 30 -
, ' ~
_,. ~,.. , . . . . . . . ~ . , ,
03-LO-4462
iO8~313~
Orthoamic acid diamines
In accordance with the present invention, it has been
discovered that certain low molecular weight oligomeric aromatic
orthoamic acid diamines, and particularly aromatic diamide-diacid-
diamines, are not only fully compatible with aqueous polyester
resin solutions, but that coatings produced from such an admixture
are clear, tough, flexible and thermally stable, and posses
surprisingly good electrical properties, including properties
which lend the resin solution to use as a magnet wire enamel in ~
conventional wire coating equipment. The orthoamic acid diamines t
referred to are low molecular weight compounds, and are distinguished ~
thereby from the known polyorthoamic acid polymers described in ~ ;
U. S. Pat. No. 3,179,614, issued April 20, 1965, to W. M. Edwards for
"Polyamide-acids, Compositions Thereof, and Process for Their
Preparation," and U.S. Pat. No. 3,652,000 and U. S. Patent -
.: :
No. 3,663,510 referred to above. The coating material described in ~ .
; U. S. Patent No. 3,652,500, after endcapping with adramine, is a
,~ long chain, high molecular weight, polyamide acid diamine. Even
`~ in the water soluble state, however, such high molecular weight
material is incompatible with water solutions of water soluble
polyester resins.
As used herein, the term "orthoamic acid diamine" or,
alternatively, the term "oligorthoamic acid diamine" is intended
to refer to and define low molecular weight compounds produced by ~ ;~
the reaction of m-moles of an aromatic diamine with (m-l)-moles of
an aromatic dianhydride, where m has a value of between 2 and about
~ 7. Because the orthoamic acid diamines are of relatively low molecular
-~ weight and have few repeating "mer" groups, they may for convenience
be referred to as "oligomers" as distinguished from "polymers" which
conventionally are of high molecular weight with many repeating ;
~ - 31 -
t . '
03-LO-4462
1()8~139
groups. In this respect, these low molecular weight compounds are
clearly distinguishable from the high molecular weight polymers,
amine endcapped polyamic acid diamines, disclosed in Pat. No.
3,652,500, for which the value of m would be in excess of 20.
Expressed another way, the orthoamic acid diamines referred to
herein have the general formula X(YX) (YX) where X represents
an aromatic diamine, and Y represents an aromatic dianhydride, and
n has a value of from 0 to about 5. The preferred range of values of
m is 2 to 4, or the equivalent preferred range of values of n is
0 to 2. Where m is 2 or n is 0, the aromatic orthoamic acid diamine
is an aromatic diamide-diacid-diamine. The aromatic diamide-diacid-
diamines are described in detail in my aforementioned copending
application, for "Coating Composition and Method of
Coating Substrates Therewith." These compounds are oligomeric
materials which are rendered water soluble by the use of ammonia
or a volatile amine. These diamide-diacid-diamines may be applied ~;
as coatings on a substrate from either an organic or an aqueous
;` solution as a coating medium to form a highly cross-linked polymeric ;~
coating on a substrate.
The orthoamic acid diamines useful in this invention
are those low molecular weight aromatic compounds produced -~
as the reaction product of an aromatic diamine and an
aromatic dianhydride, with the diamine in a one mole excess,
as defined above. The initial reaction takes place in
, 25 an aprotic solvent system which is nonreactive with or inert
~` to the diamine and dianhydride reactants. The reaction is
j carried out at a temperature below about 70~C. so that
there is a negligible level of imidization, resulting in
' the orthoamic acid product, which may be characterized,
where the reactants are to a two-to-one ratio, as a diamide-
diacid-diamine. If the reaction solution is heated under
controlled conditions, certain desired levels of imidi7ation
- 32 -
:~
o3-Lo-4 11 62
1089139
can be achieved. I-lowever, if the heating is carried too
far, SUCil ~lS to produce an imide level greater than about
90%, depending upon the particular diamine and dianhydride
selected, the imide thus formed precipitates as an lnsoluble,
inflexible, unreactive solid precipitant. Following the
formation of the reaction product of the orthoamic acid diamine,
such as the diamide diacid diamine, in an organic solvent
system, a volatile base is added in an amount sufficient
to react with that reaction product to produce a water
soluble compound. The system is then diluted with water I
to provide an essentially aqueous solution. ;~
The initial reaction between the diamine and the `
dianhydride is carried out in a high solids content organic
solvent system, with the reactants in the desired molar
ratio, such as the ratio of two-to-one, respectively, that
is ln the molar ratio of two moles of aromatic diamine
to one mole of aromatic dianhydride. To illustrate, a ;:
dlamlne, in the proportion of two moles, is first dissolved
in an organic solvent. A dianhydride, in proportion of ~;
~20 one mole, is then slowly added or trickled into the diamine
solution. The temperature is maintained generally at about
70 C. or below, and preferably at about 50 C. or below.
As the dianhydride is trickled into the diamine solution, -
one mole of the dianhydride immediately reacts with two
t~ ~ :
moles of the diamine to produce the diamide diacid diamine
monomeric coating material desired. It has been observed tha~
! ,-.
~ if the one mole of dianhydride is dissolved first, and ~
1~'~ , ,
'; : ' .
:~
~ .
-33-
03-LO-ll462
1~)8'~139
the two moles of diamine is next charged, polymerization
occurs resulting in a higher molecular weight polymeric
material and an excess of diamine. On the other hand,
lr dry dianhydride is added rapidly, such as in a chunk
or as a slug, the dianhydride reacts faster than it
dissolves, thereby leaving "islands" of unreacted dianhydride
surrounded by reacted dianhydride.
In order to convert the aromatic orthoamic acid
diamine, such as the aromatic diamide diacid diamine
reaction product, that is the O~gcmer or "polymer precursor,"~
to an aqueous based system, a volatile base is added in an
amount sufficient to convert the reaction product to a
water soluble form, followed by dilution of the system with
water to form an aqueous-organic coating medium, without
hydrolyzing or destroying the diamide diacid diamine
monomer. This reaction is generally initially carried out in
the organic solvent at a solids level greater than 40%
solids by weights, and more often greater than 50% solids
; by weight. -
The aromatic dianhydrides that are useful in
` accordance with this invention are those having the
general formula:
f' ~
O O ' ':
~C~C\
f, ~ O '~
''f. '~:: ,
,.~' :
~ -34- -
.~ ". , .: . .
03-Lo-4462
1089139
whereirl ~ is a tetravalent radical containing two benzene
rings ~oined by a chemically inert, thermally stable moiety : :
selected f`rom the group consisting of an alkylene chaln having
from 1 to 3 carbon atoms, an alkyl ester, a sulfone and
oxygen, each pair of carboxyl groups being attached to : ~.
different ~djacent carbon atoms of a single separate ring.
These dianhydrides include, for example~
4,4'-(2-acetoxy-1,3-glyceryl) bis-anhydro trimellitate,
3,3',4,4'-benzophenonetetracarboxylic dianhydride,
bis(3,4-dicarboxyphenyl) sulfone dianhydride,
bis(2,3-dicarboxyphenyl) methane dianhydride,
2,2-bis (3,4-dicarboxyphenyl) propane dianhydride, ~
bis(3,4-dicarboxyphenyl) ether dianhydride, ~ -
. .
2,2-bis(2,3-dicarboxyphenyl) propane dianhydride,
1,1-bis(2,3-dicarboxyphenyl) ethane dianhydride,
1,1-bis(3,4-dicarboxyphenyl) ethane dianhydride,
and the like.
The aromatic diamines that are useful in accordance
with this invention are those having the general formula~
`~ 20 H2N-R'-NH2
wherein R' is a divalent radical selected from the group .:
consisting of
,. ~ .
1 ~ .
r ~ .
'
-35~
03-L0-lJ IJ 6 2
1089139
_ R" '
-- Cnil2n -- Si--O --_ Si--CnH2n
R" " R" "
_ m
wherein R" ' and R" '' are an alkyl or an aryl group
having 1 to 6 carbon atoms, n is an integer of from 1
to 4 and m has a value of 0, 1 or more and
~ ~ ~;
wherein R" is selected from the group consisting of an
alkylene cnain having 1-3 carbon atoms, ;~`
_ _ ~:
R~ " R" ' R" ' R" ' R" ' : -:
-Si - , -Si-0 Si-0-,-0- P-0-,-P-,-0-?-S-
R" " R" " R" " 0
_ _ x - :
I
- S02- , and - N -
wherein R" ' and R" " are as above-defined and x is an
integer of at least 0. In general, the diamines contain
between 6 and 16 carbon atoms, in the form of one or two
: six membered rings. :~
: Specific diamines which are suitable for use in
the present invention are:
m-phenylene diamine,
p-phenylene diamine,
4,4'-diaminodiphenyl propane,
4,4'-diaminodiphenyl methane,
.
' :
--36--
., ~ . . . . . . .
: ., : .. .: . `: : :
o3-Lo-4462
~:~89~L39
benzidine ~
4,4'-dia~inodiphenyl sulfide,
4,4'-diaminodiphenyl sulfone,
3,3'-diaminodiphenyl sulfone,
4,4'-diaminodiphenyl ether,
2,6-diaminopyridine,
bis-(4-aminophenyl) diethyl silane,
bis-(4-aminophenyl) phosphine oxide,
bis-(4-aminophenyl) -N-methylamine,
1,5-diamino naphthalene,
3,3'-dimethyl-4,4'-diamino-biphenyl,
3,3'-dimethoxy benzidine, ;
m-xylylene diamine,
p-xylylene diamine,
1,3-bis-delta-aminobutyltetramethyl disiloxane,
1,3-bis-gamrna-aminopropyltetraphenyl disiloxane,
and mixtures thereof.
The organic solvents utilized in accordance with ~
this invention are those organic solvents having functional ~ ~ -
groups which do not react with either of the reactants, the
aromatic diamines or the aromatic dianhydrides, to any -
appreciable extent. In addition to being inert with
respect to the reactants, the solvent utilized must be inert
to and a solvent for the reaction product. In general, the
organic solvent is an organic liquid, other than either ~ ~
reactant or homologs of the reactants, which is a solvent ~ -
for at least one of the reactants, and which contains -
; functional groups other than monofunctional, primary and
. ,~.
"' : : :,
37
o3-L~-4 4 62
lU89139
secondary amino groups and other than the monofunctional
dicarboxyl anhydro groups. Such solvents include, for
example, N-methyl-2-pyrrolidone (sometimes abbreviated
NMP), dimethylsulroxide (DMS0)~ N-formyl moropholine (NFM), or
such organic solvents as N,N-dimethylmethoxy-acetamide,
N-methyl-caprolactam, tetramethylene urea, pyridine,
dimethylsulfone, hexamethylphosphoramide, tetramethylene~
sulfone, formamide, N-methylformamide, N,N-dimethyl
formamide, butyrolactone, or N-acetyl-2-pyrrolidone. The
solvents can be utilized alone, as mixtures, or in combination
with relatively poorer solvents such as benzene, toluene,
xylene, dioxane, cyclohexane, or benzonitrile.
The volatile bases that are useful in connection
with the present invention for produc1ng a water soluble
monomeric reaction product, include ammonia (NH3),
ammonlum hydroxide (NH40H), ammonium carbonate [(NH4)2C03]
~ and primary and secondary aliphatic amines containing up
; to four carbon atoms, such as methylamine, ethylamine,
secondary butylamine, isopropylamine, dimethylamine, ;~
diethylamine, dibutylamine, and the like.
In the initial reaction for preparing a coating
composition embodying the present invention, utilizing an
aromatic diamide diacid diamine, an aromatic diamine is -`
reacted with an aromatic dianhydride in the molar ratio
of two-to-one respectively, or in other words in the ratio
; of two moles of the former to one mole of the latter. With
reference to the above formula X(YX)n(YX), the aromatic
., . :, ,
diamide diacld diamine is produced when n equals zero, and ~ -
the molar ratio m/(m-l) holds true when m equals two. The
reaction product may be expressed by the general formula:
-38-
o3-Lo-4462
~)89139
o o
H
N~l2 - R~ - N- C \ ~ C - OH
R
~IO - C C -N -R'~ NH
ll ¦¦ H 2
0 0
wherein the arrows denote isomerisim, that is where groups ~
may exist in interchanged positions, and R and R' are as '
defined above. Such an oligomeric reaction product or a ' -
"polymer precursor" may be generally characterized as a '
"diamide-diacid-diamine." Upon additibnal of a volatile
base, a compound having the following general formula
results: ~
O O
NH2- R'- N- C \ ~ C -0~ X~
R
~X eO- C / C- N - R'- NH2 '
¦ l¦ H
: ' : ,
wherein X indicates the positive ion of the volatile'base, '~
and R and R' are as defined above. Such compound is water~
soluble so that the coating composition can be diluted with
water to form an aqueous-organic coating medium.
To illustrate the preparation of the diamide-diacid- ~ ~`
diamine more specifically, the aromatic diamine, 4,4'- i
-:: :
diaminodiphenyl methane, also termed p,p-methylene dianillne
(abbreviated ~"MDA" or simple "M"), was'mixed with an ~' '- `
aromatic dianhydride, 3~3~-4~4l-benzophenonetetracarboxylic .
; dianhydride (abbreviated "BPDA" or simply 'iB"), in the '
molar ratio of two moles of diamine to one mole of
;~ ~
` `~: ' ';~'
-39-
,: " .
o3-Lo-lJ462
1()89i39
dianhydride, in an anhydrous N-methyl-2-pyrrolidone (NMP)
solvent at about 50~ solids. The reaction was spontaneous
at a temperature below 70 C. The resulting product is
the ol;gomcr or "polymer precursor" having the formula
O O O
H2N ~ CH2~ N c B C--OH
l-IO- C C -N - ~ CH2- ~ NH2
O O
which formula may be conveniently abbreviated as "MBM."
For more details on the reaction of the diamine and
dianhydride see U.S. Patent Nos. 3,652,500 and
3,663,510 referred to above.
Similarly, p,p'-methylene dianiline was condensed ;~ -~
with 4,4'-(2-acetoxy-lj3-glyceryl)bis-anhydro
trimellitate, in the molar ratio of two-to-one, respectively ;~
in NMP solvent, at greater than 40% solids and at a
temperature generally below 70 C. The resulting oligomer
,:
or "polymer precursor" produced has the formula
O O 'O O
H2N ~ H2 ~ N- C ~ C-O-CH2-1CH-CH2-O -C ~ C- OH
HO~ C -N ~ C~2 ~ NH2
O CH3
whlch monomeric compound may be abbreviated as "MAM."
~25 Both the MBM and the MAM oligomeric compounds are
lnsoluble in water, but are made water soluble by the ;
addition of a volatile base such as ammonia or a volatile
amine. The result is a water soluble diamide-diacid-
'`' ",',
-40-
03_r.(l ~l462
108~139
diamine oligomeror polymer precursor, which is then
combined in admixture with a water soluble polyester ~-
resin described above and sufficient water to produce
a coating medium having the desired solids content.
In a selected applicacion, depending on the polyester
selected, coatings produced from the medium thus produced
are curable in a predetermined temperature range, usually
between 150 C. and 250 C., to produce clear, non-tacky :
films with excellent adhesion to the substrate. ~ ;
O~gomeric or '1polymer precursor" compounds have ~ -
been prepared from various combinations of aromatic
dianhydrides and aromatic diamines Among such compounds
are those prepared with the following molar ratio: 2.0
moles 1,3-diamino benzene, also termed m-phenylene
diamine, and 1.0 mole 3,3',4,4' benzophenonetetracarboxylic
;.. ~ :. . .
dianhydride; 2.0 moles 4,4'-diaminodiphenyl ether, also
termed p,p'-oxydianiline, and 1.0 mole of 3,3',4,4'-
benzophenone-tetracarboxylic dianhydride; 2.0 moles m-
phenylene diamine and 1.0 mole 4,4'-(2-acetoxy-1,3-glyceryl)
bis-anhydro trimellitate; 2,0 moles p,p'-oxydianiline and ~ -
1.0 mole 4,4'-(2-acetoxy-1,3-glyceryl)bis-anhydro
trimellitate. Such compounds were prepared in an N-
methyl-2-pyrrolidone (NMP) solvent, ammonia or a suitable
amine was added, and the solutions diluted with water to a ~
~25 25% solids by weight solution. -
Admixtures of aqueous solutions of polyester resins ~ -~
~and aqueous solutions of diamide-diacid-diamines prepared
~as above-described are prepared by mixing appropriate amounts
of each solution to produce the desired ratio of components.
.,:
-41-
~ c ~
03-~0-4462
1089139
Additional water may be added if necessary to produce a
coatin~ medium Or the desired consistency for the
particular coating operation.
While the weight ratio of polyester resin to
orthoamic acid diamine, such as the diamide-diacid-diamine,
can vary widely, that is from about 9 parts polyester and
1 part orthoamic acid diamine to about 1 part polyester
and 9 parts orthoamic acid diamine, the use of relatively
small amounts of the orthoamic acid diamine has produced
highlv satisfactory results. It is believed that even a ~ ;
small amount of the orthoamic acid diamine produces extensive
cross-linking in the polyester, leading to coatings having
the desired electrical properties. -~
Upon the heat curing of the admixture of polyester
1~ and orthoamic acid diamine it is believed that a highly
cross-linked ester-amide-imide structure is formed, resulting
in the unique properties achieved. The highly cross-linked
structure with the imide linkages is apparently sufficient ;~
to enhance the properties of the polymer coating and promote
the resulting cured film to an electrical grade material.
- ,
Surprisingly, even relatively small amounts of the orthoamic ~-
acid diamine are sufficient to increase and improve the
properties Or the coating film over and above properties
of films achieved from the polyester resin alone. Moreover,
~25 ln contrast to attempts to blend aqueous solutions of
polyesters with aqueous solutions of polyorthoamic acids,
which result in separate phases, the orthoamic acid diamine
and polyester blends of the present invention are fully
compatible and produce a homogeneous aqueous solution.
-42-
03-Lo-4462
1089139
~ o-h the polyester and the orthoamic acid diamine are
rnade water soluble by t~le addltion of a volatile base such as
ammonia, amrnonium hydroxide, ammonium carbonate and primary and
secondary aliphatic amines. The volatile base may be added either
before or arter admixing the polyester and orthoamic acid diamine.
In other words, an organic polyester solution may be admixed with ,~
the organic orthoamic acid diamine solution and then the mixture
made water soluble by the addition of a volatile base. Alterna~
tively, the volatile base may be added to each component separately,
each component being diluted thereafter with water and the aqueous
solutions mixed. In either case, the components are completely ~ ~
compatible with each other. Coatings can then be applied from the ~ -
combined aqueous solution to whatever substrate may be selected~ ;
including copper or aluminum, as well as magnet wire, and the coating~
cured to produce the desired cured film.
The coating mixture of the polyester and the orthoamic -~-
acid diamine may be prepared in yet another way. After preparing ~ ~-
the polyester resin and while it is still in the reàction vessel
lt is diluted with a solvent which is also a solvent for the ; `
orthoamic acid diamine. The aromatic diamine reactant as described ~ -
~above is then added to the polyester solution. A solution of the
aromatic dianhydride reactant is then added to the polyester and
diamine solution and the reaction proceeds in situ. Reactivity ~ -
of the anhydride is such that it reacts~preferentially with the `~
diamine to form the orthoamic acid diamine directly in the polyester -
solution. Thereafter a volatile base may be added and the solution ;
diluted with water to form the desired aqueous spaced coating medium.
The disadvantage of the in situ procedure however insofar as
~ subse~uent electrical properties are concerned, is that any reaction ;~
;~ 30 of the dianhydride with hydroxyl groups of the polyester leaves ;
-43-
03-Lo-4462
lV89:139
residual car~oxyl groups in l;he polymer and in the subsequently
cured coating, which may adversely affect electrical properties of
the coating. Also, with the ln situ preparat:ion it may be diffi-
cult to accurately control the formation of the desired orthoamic
acid diamlne.
It should be further noted that the cured film may be
overcoated with a Nylon coating as is conventional practice in the
magnet wire industry. It has been observed that the polyester-
orthoamic acid diamine cured coating provides a surface which is
fully receptive and adherent to the Nylon overcoating.
.
.
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iO~39139 03-Lo-4462
Polymeric Additives '~
There may be additionally admixed with the polyester ~ ,
resin minor amounts of a variety of water soluble polymers.
Among the illustrative polymers, are water soluble phenol-
formaldehyde resins, water soluble aminoplasts and watersoluble epoxy resins, as well as numerous other materials
which are conventionally added to modify the p~ perties of
coating materials. A wide variety of the above water soluhle
resins and other materials are well known and commercially ~; ~
available from a number of sources. For example, water soluble ;~' ;
phenol-formaldehyde resins are described in the Kirk-othmer
"Encyclopedia of Chemical Technology", Vol. 15, Pages 176-208,
2nd Ed., John Weley & Sons, Inc., 1968, and are commercially ~ -
~available from Union Carbide Corporation. Union Carbide resin
BRLA-2854, an amine catalyzed resin, has been added to the
~` polyester-orthoamic acid diamine solution described above~in~ ;
the amount of between about 2% and about 5% by weight. A ~
~ ~ ,. ..
~;~ commercial grade of hexamethoxymethylmelamine, "Aminop1ast~" ~ ~ ---
resin, such as American Cyanamid Company resin Cymel~301, ~ .
.-..~ -.
a water soluble hexamethoxymethylmelamine resin, can be added,
~n~ ; and the examples herein illustrate the additlon~of such a resln ~ ;~
to the solution in the amount of~between about 2 and about 5%
by weight. Such resins are compatible with polyester reSins,
epoxy resins and many others. See Gams, Widmer & Fisch,
- 25` Helv. Chem. Acta. 24 302-19E (1941). A water soluble epoxy
r~sin,~ 9uch as Ciba-G~lgy Corporation resin Araldite DP 630
,~
~ 45 1~;
i~8~139 03-LO-4462
can be utilized to advantage. The examples herein illustrate
the use of a water soluble epoxy resin in the polyester-
orthoamic acid diamine solution in the amount of between
about 2 and about 5% by weight. The addition of the various
S additives in minor amounts produces homogeneous solutions and
the resins are all fully compatible, in the proportion~
utilized, with the polyester-orthoamic acid diamine solution.
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46- ~;
o3-Lo-4462
1()89139
~low Control A~nts
In order to control the flow characteristics
of the coatîng solution, a variety of surfactants, flow
control a~ents and the like mav be added to the a~ueous
polyester orthoamic acid diamine coating solution. Among
the wide variety of available flow control agents are ~ ;~
the well known surfactants, including fluorocarbon ~
surfactants, carboxypropyl terminated dimethylsiloxane ~ -
polymer flow agents, nonylphenoxypoly(ethyleneoxy)ethanol,
also referred to as nonylphenolethylene oxide adduct,
and a mixture of cresylic acid-phenol blend with n-butyl
alcohol. The surfactants are generally added in the amount
of approximately 100 parts per million although the cresylic
acid-phenol blend and n-butyl alcohol will generally be ~ -~
added in amounts substantially greater and up to about 6%
~ 15 by wei~ht of the coating medium.
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~089139 03-Lo-4462
Examples
In the following examples, Examples 1 through 13
inclusive describe the preparation of illustrative water
solutions of various orthoamic acid diamines useful in .
this invention; Examples 14 through 22 describe the ~ -
preparation of illustrative water solutions of polyester
resins useful in this invention; Example 23 describes .
the preparation of a water solution of a high molecular
weight polyorthoamic acid diamine following the teachings
of the prior art; Examples 24 through 34 demonstrate the gene.ral~
incompatibility Or aqueous solutions of a high molecular welght .
polyorthoamic acid diamine, as prepared according to Example
:, 23, with water solutions of polyesters, such as those prepared
according to Examples 14 through 22; and Example-s 35 through ;~
75 illustrate the present invention.
, '
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~ 48~
o3-Lo-4462 ~ - .
1089139
Example 1
To a reactor equipped with a stlrrer, a nitrogen
atmosphere, an entry port, and a thermometer well,
was charged 132.2 g. N-methyl-2-pyrrolidone having a
water content below 200 p.p.m. The solvent was agitated
and 132.2 g. (0.667 mole) 4,4'-diaminodiphenyl methane
(99% purity) was added over a period of about 30 sec.
There resulted a clear solution I. To a second, similar
reactor, equipped with a heating mantle, was charged
160.7 g. N-methyl-2-pyrrolidone having a water content
below 200 p.p.m. The solvent was agitated and heated
to a temperature of 60 C., whereupon with agitation
160.7 g. (0.333 mole) 4,4'-(2-acetoxy-1,3-glyceryl)bis-
; anhydrotrlmellitate (99% purity) was added over a period ~;
of about 3 min. The temperature rose to about 80 C.
Stirring was continued for another 5 min., resulting in
a clear homogeneous solution II. The solution II was ~ ~^
cooled to about 43 C. and allowed to trickle into
solution I over a period of about 2 min. wlth agitation.
~ 20 The temperature rose to a maximum of 75 C. during the ~
; next 5 min. perlod of agitation. There resulted a clear ~ -
solution III. The percent imidizatlon was found to be ;
0.7 as determined by titration for the carboxylic acid
content in pyridine with tetrabutylammonlum hydroxide and ;
,.~ . .,
~ 25 with thymol blue as the indicator. The viscosity was ~ ~ -
. ~ .
~ 200 cps. at a solids level of 50.0% as the orthoamic acid.
, ,i -
Upon exposing 0.50 g. of sample in an aluminum cup having
a diameter of about 55 cm. to a temperature of 150 C. ~-~
~ ~ .
"':- ~ ' ' : ~
:
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~ -49- ~
o3~T.()-4462
9139
for a reriod of 90 min., the solids level was measured
as 47.9~.
The idealiæed formula of the resin thus ~roduced
in solution is:
~ O ~ O -
NH2~ }{ 2~ H-C ~ C-O- C-C- C-C-O~ C_ ~CH2 ~NH2
HO-C ~ C-OH
Il 1=0 0 ' ',
CH3
, ~.,
To 585.0 g. of the solution III, there was injected,
subsurfacewise and with agitation, 75.0 ~. of a 40% aqueous
solution of dimethylamine, over a period of 2 min. The
resultingr solution IV was clear and dilutable with water.
With agitation continuin~ a mixture of 17.0 g. ethylene
~l~col n-butyl ether, 5.8 g. N-meth~1-2-pyrrolidone, 88.o g.
water, 35.2 ~. n-butyl alcohol, and sufficient }
nonylphenolethylene oxide adduct to result ultimately in ~ ~-
45 p.p.m., was added resulting in a clear solution V ~ -
:
having a solids level at 37.5% as the orthoamic acid in
~ solution, and 36.o% as a cured film. The solution V had a
$ ~ ~ viscosity of 185 cps., and a surface tension of 38.7
dynes/cm.
: ~ ' .`' :` '':
-50-
- : : , .: .
03-Lo-4462
1089139
! Example 2
To another 585 g. of solution III of Example 1,
1 there was inJectcd, subsurfacewise and with agitation
- 44.7 ml. of 28% ammonia water over a period of 2 min.
The resulting solution IV was clear and dilutable with
; water. With agitation continuing, a mixture of 17.0 g.
¦ ethylene ~lycol n-butyl ether, 5.8 g. N-methyl-2-
pyrrolidone, 104.0 g. water, 35.2 g. n-butyl alcohol and
sufficient nonylphenolethylene oxide adduct to result
¦ 10 ultimately in 45 p.p.m., was added resulting in a clear ;
solution V, having a solids level at 37.6% as the
orthoamic acid in solution and 36.0% as a cure~ ~ilm.
The solution had a viscosity of 224 cps., surface ~`~
tension of 39.4 dynes/cm., and a pH of 7.6 at 24 C.
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03-LO-4L1~2
1~)8'3139
Exam~le 3 ~ -
To the first of the reactors of the type referred ~ ;
to in Example 1 was charged 132.2 g. N-methyl-2- ~
pyrrolidone having a water content below 200 p.p.m. The -
solvent was agitated and 132.2 g. (0.667 mole) of 4,4'-
diaminodiphenyl methane (99% purity) was charged with -~
agitation over a period of 30 sec., resulting in a
clear solution I. To the second reactor was charged
429.4 g. N-methyl-2-pyrrolidone having a water content
below 200 p.p.m. The solvent was agitated and heated
to a temperature of 50 C. whereupon 107.3 g. (O.333 mole)
of 3,3',4,4'-benzophenonetetracarboxylic dianhydride was
- charged over a period of 2 min. with agitation. Stirring
was continued for another 5 min. and the solution II
allowed to cool to 30 C. The solution II of dianhydride ~-
was then trickled into solution I with agitation over a -
period of 3 min. The stirring was continued for a period
of 10 min. resulting in a maximum temperature of 55 C.
There resulted a clear solution III. The material was ~ i
tltrated for carboxylic acid and the percent imidization `-
found to be less -than 1%. Viscosity was 104 cps. at
24 C. at a solids level of 29.9% as the orthoamic acid
solution and 28.4% as a cured film, the latter being
determined by exposing one gram of sample in an aluminum
~25 cup having a diameter of about 5.5 cm. to a temperature
of 150 C. for a period of 90 min. ~ `
The idealized formula of the resin
thus produced in solution is
-52-
.;. . .. , - . .
03-~.0-44~2
1o89139
0 O C-OI~ ~
NH2~CH2~ 1--C ~ C ~ ~C--N~3CH2~3NH2
o- f
For each 400.0 g. of solution III was added 22.4 ml-
28% aqueous ammoniacal solution, subsurfacewise and with
agitation, over a period of 1.5 min. The resulting solution
IV was clear and dilutable with water. To the reactor was
then-charged 21.1 g. of a mixture of 95% n-butyl alcohol
and 5% N-methyl-2-pyrrolidone and sufficient amount of
nonylphenolethylene oxide adduct such that the resulting
total system had about 60 p.p.m. of the latter component.
;~ There resulted a clear solution V having a viscosity of
112 cps at 24 C. at a 27.0% solids level as the ;
: 15 orthoamic acid and 25.6% as a cured film. The latter was
determined by exposing a thin film of the liquid to 150 C.
for a period of 90 min. This -solution V was water
reducible or dilutable.
.
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03-L()-44f~2
1~)8~139
Exam~le 4
To a reactor equipped with a stirrer, nitrogen
atmosphere, entry port, and a thermometer well, was
charged 108.1 g. N-formyl morpholine having a water
content below 200 p.p.m. The solvent was agitated and
108.1 g. (1.0~0 mole) m-phenylene diamine was charged
over a period of about 30 sec. There resulted a clear
solution I. To a second, similar reactor equipped with -~
a heating mantle, was charged 161.0 g. N-formyl
morpholine having a water content below 200 p.p.m. The
solvent was agitated and heated to a temperature of 50 C.
whereupon, with agitation, 161.0 g. (0.500mole) 3,3',4,4'- ~
benzophenonetetracarboxylic dianhydride was charged over ~ -
a period of 3 min. There resulted a temperature rise
to 76 C. Stirring was continued for another 5 min.
resulting in a clear homogeneous solution II. The
~ solution II was cooled to about 40 C. and allowed to
;~ trickle into solution I over a period of about 2 min. with
agitation. The temperature rose to a maximum of 73 C. ~~
during the next 5 min. period of agitation. The resulting 5
~ ,
clear solution III had a viscosity of 290 cps. and a
solids level of 50.0% as the orthoamic acid. ~-
To 269.1 g. of solution III was injected subsur~ace-
~ wise and with agitation, a mixture of 100 ml. water and 33.7
; ~ 25 ml. of 28% ammonia water over a period of 2 min. The
~; resulting solution IV was clear and dilutable with water.
With agitation continued, a mixture of 23.4 g. n-butyl
alcohol, 2.2 g. N-formyl morpholine, 100 ml. water and
:
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~54~
t)3-T.o-4462
108'~139
sufficient nonylphenolethylene oxide adduct to provide
60 p.p.m. in the total formulation, was added, resulting
in a clear solution V having a solids level of 25.9%
as the orthoamic acid and 24.2~ as a cured film. The
solution had a viscosity of 288 cps., a surface tension
of 37.0 dynes/cm., and a pH of 7.4 at 24 C.
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n3-L()-4462
1~89~39
Exarn~le 5
To a reactor equipped wlth a stirrer, nitrogen
atmosphere, cntry port and a thermometer well, was
charged 200.4 g. N-methyl-2-pyrrolidone. The solvent
was agitated, and 200.4 g. (l.OOOmole) 4,4'-
diaminodiphenyl ether was charged over a period of 30
sec. There resulted a clear solution I. To a second,
similar reactor equipped with a heating mantle, was ;~
charged 161.0 g. N,N-dimethylformamide. The solvent was
heated to a temperature of 50 C., whereupon, with
agitation, 161.0 g. (0.500 mole) 3,3',4,4'-
benzophenonetetracarboxylic dianhydride was charged
over a period of about 3 min. There resulted a
temperature rise to about 70 C. Stirring was continued
for another 5 min. resulting in a clear homogeneous
solutlon II. The solution II was cooled to about 37 C.
and allowed to trickle into solution I over a period of ~
about 3 min. with agitation. The temperature rose to a ~ ~ -
maximum of 68 C. during the next 10 min. period of ~ ~
~ , .
- 20 agitation. The resulting clear solution III had a
viscosity of 214 cps. and a solids level of 50.0% as the
orthoamic acid. The percent imidization was determined
~ from a titration of the carboxylic acid groups and found
i to be 1.2%.
To 270.0g. of solution III was in~ected, subsurfaoewlse ;~
and with agitation, a mixture of 93 ml. water and 18.5 ml.
of 28% ammonia water over a period of 2 min. The resulting
solution IV was clear and dilutable with water. With -
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n3-L()-4462
1089139
agitation continued, a mixture Or 23.4 g. n-butyl alcohol
2.2 g. N-methyl-2-pyrrolidone, 100 ml. water, and
sufficient nonylphenolethylene oxide adduct to provide
60 p.p.m. in the total formulation, was added, resulting
in a clear solution V having a solids level at 25.7% as
a cured film. The solution had a viscosity of 233 cps.,
a surface tension of 37.2 dynes/cm., and a pH of 7.0 at
24 C.
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03-L()-41162
i()~9 1 39
Example 6
To a reactor equipped with a stirrer, nitrogen
atmosphere, entry port and a thermometer well, was
charged 108.1 g. N-~ethyl-2-pyrrolidone followed by
108.1 g (1.000 mole) m-phenylene diamine, resulting in a
clear solution I. To a second, similar reactor
equipped with a heating mantle, was charged 241.0 g. ;
N-methyl-2-pyrrolidone. The solvent was heated to 55 C.
whereupon with agitation 241.0 g. (0.500 mole) 4,4'-(2-
acetoxy-1,3-glyceryl)bis-anhydrotrimellitate was charged
over a period of 3 min. and stirring continued for an
additional 10 min. period during which the temperature
: r reached a maximum of 68 C. The solution II was cooled
to about 30 C. and allowed to trickle into solution I
with agitation over a period of 3 min. The temperature
peaked at 65 C. during the additional 15 min. period of ~-
stirring. The resulting homogeneous solution III in the
reactor was allowed to cool to 35 C. whereupon with
agitation a mixture of 200 ml. water and 67.0 ml. of 28% - ;
ammonia water was injected subsurfacewise over a period of
2.5 min. resulting in a clear solution IV. With agitation -
` continuing a mixture of 50.0 g. n-butyl alcohol, 4.0 g. N-
methyl-2-pyrrolidone, 200 ml. water, and sufficient
nonylphenolethylene oxide adduct to provide 45 p.p.m., was
:: : :-
added. The resulting clear solution V had a solids level
of 29.0% as the orthoamic acid in solution and 27.4% as a
~` cured film. The solution had a viscosity of 175 cps., a
surface tension of 36.8 dynes/cm., and a pH of 7.1 at
~ 24.5 C. ~
i~ -58- `
n3~ 62
1089139
Example 7
To the rlrst of the reactors of the type referred
to in Example 4 was charged 132.2 g. I~-formyl morpholine
having a water content below 200 p.p.m. The solvent
was agitated and 132.2 g (0.667 mole) of 4,4'- -
diaminodiphenyl methane (99% purity) was charged resulting
in a clear solution I. To a second similar reactor
equipped with a heating mantle was charged 429.4 g. N-
formyl morpholine having a water content below 200 p.p.m.
The solvent was agitated and heated to a temperature of
58 C. whereupon 107.3 g. (O.333 mole) of 3.3l~414'-
benzophenonetetracarboxylic dianhydride was charged over
a period of 4 min. with agitation and the stirring
continued for an additional period of 15 min. After
cooling to 2~ C. the solution II of dianhydride was
trlckled into the solution I in the first reactor with
agitation over a period of 7 min. The stirring was
continued for a period of about 15 min. The maximum
temperature was 74 C. The resulting clear solution III
was titrated for carboxylic acid and the percent imidization
found to be o.6%. The contents of the reactor were allowed
to cool to 3? C. To the reactor was added 65.6 g. of a
~ 60% aqueous solution of is,opropylamine, subsurfacewise and
;~ with agitation over a period of 2.5 min. resulting in a
clear solution IV. To the reactor was then charged 42.0 g.
of a mixture of 95% n-butyl alcohol and 5% N-formyl
morpholine and sufficient nonylphenolethylene oxide
~ adduct such that the resulting solution V was at 50 p.p.m. -
-~ with respect to the nonionic surfactant. The clear
'
_ 5 9_
o~-Lo-lJ462
108~139
solution had a viscosity Or 278 cps. at 25 C. and a
solids level of 27.5% as the orthoamic acid and 26.1% as
the cured rilm. The solution was water reducible.
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03-L0-4462
~0~ 9
Examples 8 through 10 represents the preparation of a
series of resins of the type M(AM) AM where X=l, X=3 and X=5,
respectively, M represents 4,4'-diaminodiphenyl methane and A
represents 4,4'-(2-acetocy-1,3-glyceryl)bis-anhydrotrimellitate.
In comparison, Example 1 represents the resin where X=0.
Example 8
To a reactor equipped with a stirrer, nitrogen atmos-
phere, entry port, and a thermometer well was charged 124.8 g.
N-methyl-2-pyrrolidone having a water content below 200 p.p.m~
The solvent was agitated and 24.8 g. (0.125 mole) 4,4'-diamino-
diphenyl methane (99% purity) was charged over a period of about
30 sec. There resulted a clear solution I. To the reactor was
added a solution a 40.2 g. (0.0832 mole) 4,4'-(2-acetoxy-1,3-
glyceryl)bis-anhydrotrimellitate (99% purity) in 40.2 g. N-methyl- ~ ;~
2-pyrrolidone over a period of about 2 min. with agitation.
Stirring was continued for another 10 min. resulting in a clear
homogeneous solution II having a solids level of 28.3% as the ortho-
amic acid. The percent imidization was found to be 0.4. This ~ ;
provided a molar ratio of M/A--3/2 and an average structure of
~ ~.
M(AM) AM where X=l. To the contents of the reactor was added,
subsurfacewise and with agitation, 11.4 ml. of 28% ammonia
water over a period of 2 min. The resulting solution III
was clear and dilutable with water. With agitation
continuing, a mixture of 4.3 g. ethylene glycol n-butyl
ether, 1.7 g. N-methyl-2-pyrrolidone, 26.0 g. water, 13.2 g.
n-butyl alcohol and sufficient nonylphenolethylene oxide
:
:' " ': . .
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,
03-LO-4462
108~3139 : :`
adduct to result ultimately in 45 p.p.m. was added
resulting in a clear solution IV having a solids level of
22.8% as the orthoamic acid and 21.7% as the cured film
(see Example 1). The solution had a viscosity of 32 cps.,
surface tension of 41.5 dynes/cm. and a pH of 7.2 at 24C. ~
~,
- 62 -
::.:: .
:' ~ '' '
,.
03-LO-4g62
108~9139
Example 9
To the reactor of Example 8 was charged 120.7 g.
N-methyl-2-pyrrolidone. The solvent was agitated and
20.7 g. (0.104 mole) 4,4'-diaminodiphenyl methane was
charged over a period of about 30 sec. There resulted
a clear solution I. To the reactor was added a solution
of 40.2 g. (0.0832 mole) 4,4'-(2-acetoxy-1,3-glyceryl)
bis-anhydrotrimellitate in 40.2 g. N-methyl-2-pyrrolidone,
over a period of about 2 min. with agitation. Stirring
10 was continued for another 10 min. resulting in a clear
homogeneous solution II having a solids level of 27.4%
as the orthoamic acid. The percent imidization was
found to be 0.4%. The provided a molar ratio of M/A~5/4
and an average structure of M(AM) AM where X=3. To the
lS contents of the reactor was added, subsurfacewise and with
agitation, 11.4 ml. of 28% ammonia water over a period of
2 min. The resulting solution III was clear and dilutable
with water. With agitation continuing a mixture of 4.3 g.
ethylene glycol n-butyl ether, 1.7 g. N-methyl-2-pyrrolidone,
20 26.0 g. water, 13.2 g. n-butyl alcohol and sufficient -~
nonylphenolethylene oxide adduct to result ultimately in
45 p.p.m. was added resulting in a clear solution IV having
a solids level of 22.0~ as the orthoamic acid and 21.0% as ~- -
the cured film. The solution had a viscosity of 30 cps.,
25 surface tension of 40.5 dynes/cm. and a pH of 7.0 at 24 C.
`.'~,~
- 63 -
''. : , '' ' ' ' ' . . ': ', ' , ~ '
03-L0-4462
~ .'3139
Example 10
To the reactor of Example 8 was charged 119.3 g.
N-methyl-2-pyrrolidone. The solvent was agitated and 19.3 g.
(0.0975 mole) 4,4'-diaminodiphenyl methane was charged over a period
of about 30 sec. There resulted a clear solution I. To the reactor ~ -~
was added a solution of 40.2 g. (0.0832 mole) 4,4'-(acetocy-1,3
glyceryl) bis-anhydrotrimellitate in 40.2 g. N-methyl-2-pyrrolidone,
over a period of about 2 min. with agitation. Stirring was
continued for another 10 min. resulting in a clear homogeneous
solution II having a solids l~vel of 27.2% as the orthoamic acid.
The percent imidization was found to be 0.5%. This provided a molar
ratio of M/A-7/6 and an average structure of M(AM) AM where X=5.
To the contents of the reactor was added, subsurfacewise and with
agitation, 11.4 ml. of 28% ammonia water over a period of 2 min. -~
The resulting solution III was clear and dilutable with water.
With agitation continuing a mixture of 4.3 g. ethylene glycol
n-butyl ether, 1.7 g. N-methyl-2-pyrrolidone, 26.0 g. water,
13.2 g. n-butyl alcohol and sufficient nonylphenolethylene oxide
adduct to result ultimately in 45 p.p.m., was added resulting in a
clear solution IV having a solids level of 22.8~ as the orthoamic -~
acid and 21.7~ as the cured film. The solution had a viscosity
of 30 cps., surface tension of 40.7 dynes/cm. and a pH of 7.0 at `~ - ;
;`~ 24 C. ~ ~
~ ` '
~,
.
~ - 64 -
, . .. . . . . . . . . .
o 3-Lo-4462
1~'3139
Examples ll through 13 represent the preparation
of a series of resins of the type M(BM) BM where X=l,
X=3 and X=5, respectively, M represents 4,4'-diaminodiphenyl
methane and B represents 3,3',4,4'-benzophenonetetracarboxylic
dianhydride. In comparison, Example 3 represents this
resin where X=0 and Example 23 below where X is in excess
of 20. -
Example 11 ;
To the reactor of Example 8 was charged lO0.0 g.
of a 50.0% by weight solution of 4,4'-diaminodiphenyl ;
methane (0.242 mole) in N-methyl-2-pyrrolidone resulting ~ ~
in solution I. To the reactor was added, slowly, over ~ ;
a period of about 2 min. with agitation, 471.0 g. of a
11.5% by weight solution of 3,3',4,4'-benzophenonetetracarboxylic
dianhydride (0.168 mole) in N-methyl-2-pyrrolidone.
Stirring was continued for another lO min., resulting in a
clear homogeneous solution II having a solids level of 18.2%
as the orthoamic acid. The percent imidization was found
to be 0.3%. This provided a molar ratio of M/B--3/2 and -
an average structure of M(BM) BM where X=l. To the contents
of the reactor was added, subsurfacewise and with agitation,
23.1 ml. of 28% ammonia water over a period of 2 min. The ~ -
resulting solution III was clear and dilutable with water
and at a solids level of 17.6% as the orthoamic acid and
16.6% as the cured film. The solution had a viscosity of `
40 cps., surface tension of 45.1 dynes/cm. and a pH of
8.2 at 24 C.
' .''-`
.~:
- 65 -
.. ,~.. ~.... .. . .
3139
03-L0-4462
Example 12
To a reactor of Example 8 was charged 100.0 g. of
a 50.0% by weight solution of 4,4'-diaminodiphenyl methane `~
(0.252 mole) in N-methyl-2-pyrrolidone resulting in
solution I. To the reactor was added, slowly, over a period
of about 2 min. with agitation 565.3 g. of a 11.5% by
weight solution of 3,3',4,4'-benzophenonetetracarboxylic
dianhydride (0.202 mole) in N-methyl-2-pyrrolidone. Stirring
was continued for another 10 min. resulting in a clear
homogeneous solution II having a solids level of 17.3% -
as the orthoamic acid. The percent imidization was found
to be 0.5%. This provided a molar ratio of M/B=5/4
and an average structure of M(BM) BM where X=3. To the
contents of the reactor was added, subsurfacewise and ~ .
with agitation, 27.7 ml. 28% ammonia water over a period of ~. ;
2 min. The resulting solution III was clear and dilutable ;-
with water and at a solids level of 16.7% as the orthoamic -
acid and 15.6% as the cured film. The solution had a
.
viscosity of 46 cps., surface tension of 44.4 dynes/cm.
and a p~ of 8.0 at 24 C. -~
:. :
,.'. . ,
- 66 -
:.
; ~ :
03-Lo-4462
108'-~139
Example 13
To the reactor of Example 8 was charged 100.0 g.
of a 50.0% by weight solution of 4,4'-diaminodiphenyl
methane (0.252 mole) in N-methyl-2-pyrrolidone resultlng
in solution I. To the reactor was added, slowly, over
a period of about 2 min. with agitation 605.6 g. of a
11.5% by weight solution of 3,3',4,4'-benzophenonetetracarboxylic
dianhydride (0.216 mole) in N-methyl-2-pyrrolidone. Stlrring
was continued for another 10 min. resulting in a clear
homogeneous solution II having a solids level of 16.9% as
the orthoamic acid. The percent imidization was found to
be O.4%. This provided a molar ratio of M/B-7/6 and an
average structure of M(BM)XBM where X=5. To the contents
of the reactor was added, subsurfacewise and with agitation,
29.7 ml. 28% ammonia water over a period of 2 min. The
resulting solution III was clear and dilutable with water
and at a solids level of 16.3% as the orthoamic acid and
~; 15.2% as the cured film. The solution had a viscosity of
40 cps., surface tension of 44.5 dynes/cm., and a pH of
8.o at 24 C.
'' ~'' ~.'~
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.
,
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()3~ -44~2
lVt~3139
Exam~le 14
To a reactor equipped with heatlng mantel, nitrogen
sparge, stirrer and thermometer, was charged 225.0 g. `
(2.160 mole) neopentyl glycol. The heat was turned on
and at about 100 C. after the neopentyl glycol was ; ~-`
liquified, 185.0 g. (0.963 mole) of trimelletic anhydride
was added over a period of about 3 min. The mixture
was held at 100 C. for about 10 min. whereupon the
mixture was clear. The temperature w~s raised to 170 C.,
,. .
and 95.0 g. (o.650 mole) of adipic acid was added. The ;~
,:
reactor was held at this temperature with read-outs of `
the acid number every hour. After about 5 hrs. at this
temperature, an acid number of 56 was obtained. The acid
number was determined in acetone rather than the ~-
conventional benzene-ethanol solution slnce this resin
is insoluble in the latter. To this resin system was
added 8.3% dimethylethanol amine made up as a solution in
water/t-butyl alcohol = 85/15, such that the resin ~`
solids level was 33.6%. There resulted a slightly hazy
solution having a pH of 7.4 and a viscosity of 8700 cps
at 25 C. The polymer in this form was water reducible.
.
The idealized structure for this polymer befare the amine
addition is as follows~
~ :.
::` `
'~:
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,
-68-
.' i `l', ' ' , ' ' ` ' `
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03-L()-4462
1(~89139
HO--U--O--C - ~ O,~COOH
,~L C-0-R--O--C-- (CH2)4--C--O--R--O-- C~O
HO--R----e
O O O O O
O R
HO -R -O-C ~L
HO-R-O-C C--O--R--O--IC--(CH2 )4 -- C O ~ -
O O ,:
When R represents neopentyl glycol.
;. ' '
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-69- -`~
0,~-I,0-4/162
108913~
ExamDle 15
To a reactor equipped with a heating mantel,
nitrogen sparge~ stirrer and thermometer, was charged
245.0 g. (3.219 moles) propylene glycol followed by
255.0 g. (1.327 moles) trimelletic anhydride and 65.0 g.
(0.445 mole) adipic acid. The temperature was raised
to 172 C. and held at this temperature until the acid
number dropped to about 56, which occurred in about
6 hrs. Since this resin was insoluble in the conventional
benzene-ethanol solvent, the acid number was determined
in acetone.
The resin system was cooled and trickled into an
agitating solution Or about 8.3% dimethylethanol amine -
in water such that the resulting solution was at a
solids level of 34.2% and a pH of 7.6. There resulted
a slightly hazy solution with a viscosity of 9400 cps.
at 25 C. The polymer in this form was water reducible. ~-
The idealized structure of this polymer, before the amine
addition, is as follows:
O-R-OH
HO-R-O-C- ~ ~ COOH O ~ -
C-O-R-O-C ~ O~
~~-R~~C~(cH2)4
O .~
~ R
; ~ : O I - :
HO-- R- O -C ~ ~
HO- R- O -C . .
:, . o
Where R represents propylene glycol.
-70-
:.. ~: .. : . . . . , : .
n3-r,0-4462
~0tS9139
Example 16
Using the reactor referred to in Example 15, the
following charge was employed: 255.0 g. (2.829 moles)
butylene glycol ~1-3); 232.5 g. (1.210 moles) trimelletic
anhydride; and 60.0 g. (0.410 mole) adipic acid. Using
a slmilar set of reaction conditions, there resulted
after a process time of 6 hrs. at 172 C., an acid number
of 55. The polymer was treated with an aqueous solution
of dimethylethanol amine in the same manner as in
Example 15, resulting in a slightly hazy, water reducible,
solution having a viscosity of 9000 cps at 25 C. at
33.9% solids and a pH of 7.4. The idealized structure
is similar to that shown in Example 15 with R representing ~ -
butylene glycol. ~ -
`,~.. "'
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. ~
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-71- ~
o3-Lo-4462
1~89139
ExamPle 17
Using the reactor referred to in Example 15, the
following charge was employed: 275.0 g. (2.640 moles)
neopentyl glycol was charged and heated to 172 C.;
wlth agitation, 217.5 g. (1.132 moles) trimelletic
anhydride was added and the temperature held for 12 min.,
resulting in a clear solution; with temperature held at
171 C.; 55.0 g. (o.376 mole) adipic acid was added. The
contents of the reactor were held for about 6 hrs. at 172 C.
until an acid number of 55 was obtained. The polymer
solution was cooled and treated with an aqueous solution
of ammonia such that the resulting 34.2~ solids solution
; had a pH of 7.4. The water reducible system had a
:::
viscosity of 8100 cps. at 25 C. The idealized structure
is similar to that shown in Example 15 with R representing
neopentyl glycol.
::
:~
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'` ~ : : ::
~ '
, :
'
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.-, '
-72-
_~_, .. , .. , ... _ _ ., _ ,.. .. ... , . ...... .... _ _ ___ _ _
; ;, .. . .
o3-Lo-4462
313~
Example 18
To a reactor equlpped with heatlng mantel, nitrogen
sparge, stirrer and thermometer, was charged 166.1 g.
(1.000 rnole) of terephthalic acid followed by 96.0 g.
(o.500 mo~) trimelletic anhydride and 318.4 g. (3.000 moles)
Or diethylene glycol. The temperature was increased
to 200 C. and maintained for about 2 1/2 hrs. There
resulted a clear solution. An additional 96.0 g. ~ ~
(O.500 mole) of trimelletic anhydride was then added to
the hot solution with heating and agitation maintained
until an acid number of about 50 was attained. The 100%
solids system was treated at about 60-80 C., with warm
water containing sufficient methyldiethanolamine to
result in a 34% solids solution having a pH of 7.2, -
and a viscosity Or 1315 cps. at 25 C. The resulting
.,, ~ .
polymer solution was water reducible and was observed
to be stable for time periods in excess of three months.
' .', ~ '
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n3-r,~ 2
1089139
Exam~le 19
To the reactor described in ~xample 18 there
was charged 384.2 g. (2.000 moles) of trimelletic anhydride
(TMA) and 319.4 g. (3.000 moles) of diethylene glycol. The
temperature was increased to 195 C. and maintained for
about 3 1/2 hrs., resulting in a clear solution of fused
polymer having an acid number of about 53. After
treatment with methyldiethanol amine and water to 34%
solids, the polymer solution was slightly hazy, had a
pH of 7.4 and a viscosity of 70 cps. at 25 C. The
resulting polymer solution was water reducible and stable
for time periods in excess of three months.
.
-74-
.,.; ~ , :
03-L()-11462
:11)8'3139
~xam~le 20 ~ ;
.
To a reac~or equipped with heating mantel, nitrogen
sparge, s~irrer and thermometer, was c~larged 222.8 g.
(2.140 moles) neopentyl glycol. The temperature was ~-
raised to 173 C. To the fused glycol, under nitrogen,
with stirring and with the temperature controlled at
173 C., was added 130.6 g. (0.500 mole) tris(2-hydroxyethyl)
isocyanurate. To the reactor then was charged 217.5 g.
(1.132 moles) trimellitic anhydride and the temperature
held for about 15 min., resulting in a clear solution to
which was added 55.0 g. (o.376 mole) adipic acid. The
contents of the reactor were held at 173 C. for about
6.5 hrs. until an acid number of 58 was obtained. The
polymer solution was then treated with an aqueous solution
of dimethylethanol amine. The resulting slightly hazy
water reducible solution had a solids level of 34.5%, a pH ~-
- .
~ of 7.8 and a viscosity of 5900 cps. at 25 C.
~ ' ''`, ' .
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. ' .
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- `',.' :'~-:
.
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~ :
-75-
... .. . . .
03-LO-4~162
10~9139
Example 21
'I`o a reactor equipped with a heating mantel, nitrogen
sparge, stirrer an~ thermometer, was charged 245.0 g. (3.219
moles) propylene glycol, fo~owed by 255.0 g. (1.327 moles) tri-
mellitic anhydride, and 73.9 g. (0.445 mole) isophthalic acid.
The temperature w~s raised to 170C. and held for a total of about
6.5 hrs. resulting in a clear resin having an acid number of 62,
forming polyester system I. The resin system I was cooled and
trickled into an agitating solution of about 8.3% dimethylethanol
10 amine in water, so that the resulting solution was at a solids -;
leyel of 33.6% and a pH of 7.8. The slightly hazy solution had a
visoosity o~ 3700 cps. at 25C. The polymer in this form was
water reducible. The idealized structure of this polymer is about ;~ - -
as shown in Example 15, differing in that the aliphatic tCH2t4
15 group would be replaced by the aromatic tC6H4~ group. `~
.:
,
: ' ~
'.
-76-
~3-1,0-4462
108~139
Example 22 :
The synthesis o.f Example 21 was repeated except ~ :;
that instead Or using 0.445 mole of isophthalic acld,
there was added a mixture of 43.8 g. (0.300 mole) of ::
isophthalic acid and 84.4 g. (0.145 mole) of the reaction
product of 2 moles of trimelletic anhydride and one mole
of 4~4'-methylene dianiline having the structure
HOOC ~ n _ ~ CH2 ~ N ~ COOH
O
and a calculated molecular weight of 582.4. The
: temperature l~as raised to 174 C. and held for about 7.5 hrs., `
resulting in a polymer havin~ an acid number of 66. The ;.
resin system was cooled and trickled into an agitating ::
solution Or about 8.3% dimethylethanol amine in water so - ?~
that the resulting solution had a solids level of 34.2%
and a pH of 7.4. The slightly hazy solution had a
.: -
:; viscosity of 7400 cps at 25 C. The polymer in this form
n 20 was water reducible.
~ .-.:.
.
".
~ .
.. . ..
:
. -77- :~.
03-Lo-4462
108'~ 9
It is very evident that the number of useful water
reducible polyesters is substantially unlimited. It is
not the purpose of this presentation to show how many
kinds of polyesters can be made, but to show the unexpected
finding that an imide forming orthoamic acid amine has
been identified that is fully compatible with water
soluble polyesters. High molecular weight polyamides are
well established and are also well known to be costly.
The combination of water soluble high molecular weight
polyamide acids with water soluble polyesters was futile
as is evidenced in Example 23. However, the combination
with an orthoamic acid diamine prepared according to
, Examples 1-13 was unexpectedly found to result in
compatible solutions and thermally very stable cured resin ~ ~;
systems, which had surprisingly good electrical properties.
.
:: ' ' ;. :
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-78-
" ~.,.,..... . ~ . . . .
o3-Lo-4462
10~9139
Example 23
A Regal mixer equipped with cooling to the jacket
was flushed with dry nitrogen, de~point -65 C. and
charged with 3760 g. of dry N-methyl-2-pyrrolidone
(C 0.01% water), followed by 360 g. (1.818 moles) p,p'-
methylene dianiline, (~99.7~purity). After stirring for
about one minute, 293 g. (O.909 mole) 3,3'~4,4'-
benzophenonetetracarboxylic dianhydride, (=~99.5% purity),
was added with stirring over a period of 5 minutes and
the stirring continued for 15 minutes. The maximum -~
temperature during this period was 35 C. The temperature
was reduced to 25 C. and 299 g. (0.927 mole) of 3,3',4,4'- `;~ '
benzophenonetetracarboxylic dianhydride was added dropwise ;
. . .
; . .i .
over a period of 15 min. with agitation and with the
exotherm temperature rise controlled at a max. of 40 C.
The resulting polyorthoamic acid solution was clear and had
a solids content of 20.2%. The carboxylic acid content was
~; determined by titration with t-butylammonium hydroxide in ; ~ ~-
pyridine to a thymol blue end point and the percent
lmidization calculated to be o.6 + 0.5%, or essentially a -~
negliglble amount. The inherent viscosity was determined
in N-methyl-2-pyrrolidone at 37.8 C. and found to be
0.60 dl./g. at C = 0.500 g./dl. The kinematic viscosity
of the system was ?400 cps at 40 C.
25~ To the reactor was added, continuously, dropwise, `~
and with agitation, over a period of 15 min., a solution ~:
of 3.6 g. (0.018 molej of p,p'-methylene dianiline in
100 g. of N-methyl-2-pyrrolidone and the mixing continued
~, , , -
.
-79_
o3-L(~-4462
9~39
under nitrogen and with cooling and with the temperature
mained at about 40 C. After an additional 45 min. of
mixing the kinematic viscosity was found to be 4700 cps
at 40 C., and the inherent viscosity was 0.82 dl./g.
After formation of the-polymer, 200 g. of conc.
ammonium hydroxide was added to the Regal mixer with
mixing. This was followed by addition of 600 g. of
distilled water and the system stirred for about 30 min.,
resulting in a clear, aqueous based, polymer solution.
The polymcr system was treated with a flow control agent
by adding 0.6% by total system weight of a conventional
nonionic, nonylphenolethylene oxide adduct. The resulting
product was a clear solution having a solids content of ~-~
17.2% and a viscosity of 480 cps at 23.8 C. The solution :
was employed to coat copper wire in a conventional wire
enameling tower. The resulting 3.0 mil. build coating was
.
~ found to pass 25% elongation and lX flexibility.
.~ :: ~ , .
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-B0-
..
. . . ~ .: . . .. : -
o3-Lo-4462
i;39
:
Example 24
To a reactor, equipped with a stirrer, was charged ;~
120.0 g. of the polyester as prepared in Example 14 at
33.6% solids. Over a period of 2.0 min., 30.0 g. of the
aqueous 17.2% solids polyorthoamic acid polymer solution
prepared in Example 23 was added to the contents of the
reactor. The stirrer was operated for an additional
period of 15 min. This resulted in a polyester to
polyorthoamic acid polymer resin ratio of about 9/1. ;
Upon standing, a phase separation occurred, resulting
in a polyorthoamic acid polymer rich layer at the top and
. ~ . . .
a polyester rich layer at the bottom, indicating ;~
incompatibility of the polymer blend. - ~
- . :.
....: .::
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-
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-81-
03_r~-4l162
1~8~ 9 ,, ~
Example 25-32
In a manner slmilar to that in Example 24 a
series of` polymer solution blends were attempted using
120.0 g. of each Or the polyesters prepared in Examples
15-22 with 30.0 g. of the aqueous 17.2% solids
polyorthoamic acid polymer solutions prepared in
Example 23 as follows:
Example 25 120.0 g. polyester Or Example 15 + 30.0 g.
polymer solution of Example 23 - ~-
Example 26 120.0 g. polyester of Example 16 + 30.0 g.
polymer solution of Example 23. ~-
Example 27 120.0 g. polyester of Example 17 ~ 30.0 g.
polymer solution of Example 23. ~:
Example 28 120.0 g. polyester of Example 18 + 30.0 g. -~
polymer solution of Example 23.
Example 29 120.0 g. polyester of Example 19 + 30. o g. ~ ~
polymer solution of Example ?3. -
Example 30 120.0 g. polyester of Example 20 + 30.0 g.
polymer solution of Example 23.
Example 31 120.0 g. polyester of Example 21 + 30. o g. -
polymer solution of Example 23.
Example 32 120.0 g. polyester of Example 22 + 30. o g.
polymer solution of Example 23.
In each instance the polyester rejected the polyorthoamic ~ -
acid polymer, resulting, in each instance, in a phase
separation with formation of a polyorthoamic acid polymer ~ ;
~rlch layer and a polyester rich layer. ~
, ''"~ "
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-82-
,: . :
n3-r,n-4462
~,o~
Example 33
To a reactor, equipped with a stirrer, was charged
90.0 g. o~ an aqueous 33.6% solids solution of a polyester ;
as prepared in ~xample 21. Over a period of 2.0 min., 60.0 g.
of an aqueous polyorthoamic acid polymer solution as
prepared in Example 23, at 17.2% solids, was added to the
contents of the reactor. The stirrer was operated for an -
additional period of 15 min. This resulted in a polyester
to polyorthoamic acid polymer resin ratio of about 75/25.
On standing, a phase separation occurred, resulting in
a polyorthoamic acid polymer rich layer at the top and a
polyester rich layer at the bottom, indicating incompatibiiity
~;~ of the polymer blend.
.~
~: .: ~:
~,
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:
~ -83-
n3-L~-ll462
10t~ 39
Example 34
To a reactor, equipped with a stirrer, was charged
135.0 g. of the 33.6~ solids polyester solution as prepared
in Example 21. Over a period of 2.0 min., 15.0 g. of the
polyorthoamic acid polymer solution as prepared in
Example 23, at 17.2% solids, was added to the contents
of the reactor. The stirrer was operated for an additional
period of 15 min. This resulted in a polyester to ;
polyorthoamic acid polymer resin ratio Or about 95/5.
On standing, a phase separation occurred, resulting in
polyester and a polyorthoamic acid polymer resin rich
regions, indicating the tolerance of the polyester polymer
for polyorthoamic acid polymer is apparently weIl below
5%.
~ ,,,-,. :,:
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-84-
; . .. . . . :. .
03_rJn-4462
10891;~9
Example 35
.
'l'o a reactor equipped with a stirrer was charged
180.0 g. of an aqueous solution of a polyester at 33.6% solids
prepared according to Example 21 followed by 18.8 g. of the
aqueous solution of the orthoamic acid prepared by the
procedure described in Example 1 at 36.o% solids (as the
cured film). Stirring was continued for a period of 15
min. The resin cured weight ratio of polyester to
orthoamic acid diamine was at about 9 to 1. In sharp
contrast to the result obtained in Example 24, there ~ ~
resulted a clear solution with no evidence of phase separation. ~ -
To the reactor, with agitation, was added 10.0 g. of a
mixture of 9.5 g. n-butyl alcohol and 0.5 g. N-methyl-2~
pyrrolidone containing a sufficient amount of nonylphenolethylene
oxide adduct such that the resulting system had about 60 p.p.m. ;~
of the latter component. The resulting clear aqueous
solution of the polymer blend had a solids level of 32.2~
a surface tension of 36.5 dynes/cm., a pH of 7.5 and a ~ ~`
vlscosity of 347 cps. at 24 C. The solvent in this system
is in excess of 80% water. About 0.5 g. of the solution was
placed in an aluminum dish about 5.5 cm. in diameter. The
"
solution flowed out evenly. The sample was placed in a
forced-air oven set at 150 C. for 15 min.- and then removed
and examined. It was found to be a homogeneous clear film
: :.
~ 25 free of any phase separation. The cure was continued for
,-~
90 min.~ at 220 C. followed by 20 min. at 250 C. There
resulted a clear, tough 0.3-1.0 mii film exhibiting excellent
adhesion to and flexibility on the aluminum substrate. ~
~ ~.
.
~ -85- -
o3~ -4462
1089i3~
Another poItion of the solutlon was placed on a copper
substrate and another on an iron substrate and a doctor
blade employed to draw uniform wet films. A similar cure
schedule was cmployed and the resulting O. 2-0.5 mil films
were found to be clear, tough, and exhibiting excellent
adhesion to the substrates as evidenced by no separation
at the interface following considerable flexing.
The 32. 2% solids solution was employed to coat 18
AWG wires, O. o403 inch copper and aluminum wire, using a
conventional set of six wire enamel metering dies, namely,
0.043, o.o44, o.o44, o.o45, 0.045, and o.o46 inch diameter ~;~
opening. Each of the wet drawn enamel films was cured with ~;
the aid of forced-air ovens before the next layer of wet
film was applied. The resulting films were smooth and
concentric. The film build was 2. 8 to 3.0 mil on the
diameter. A description of the mechanical, chemical,
electrical and thermal test methods have been presented `~
above. The mechanical properties of the film included~
flexibility of 25% and lX on copper and 15% and lX on
- -. . .. .
20 aluminum; repeated scrape 15-25 strokes; unidirectional `~
scrape resistance 1020 g.; passed snap elongation. The
chemical properties of the film included: pass of 70/30 and
50/50 solvent resistance test. The electrical properties ~-
of the film included: strength in excess of 2000 v./mil
in twisted pair test. The thermal properties of the film
included: cut-through temperature (see table below), -
155 C. heat shock passed at 2X-3X; 175 C. heat aging
passed 3X.
~, .
!
~ ~ -86- -
03-LO-4ll62
1~8~?139
.
The above coated six pass wire was overcoated with
a convcntional Nylon wire enamel, namely, a solution of
15% 6,6-Nylon dissolved in a 70/30 cresylic acid/hydrocarbon
solven~. This was accomplished with an 0.047 inch diameter , ;
opening for the seventh pass. The wet drawn Nylon film was
cured with the aid of forced-air ovens. The resulting -
fllm composlte was smooth. A slight improvement was found
in the heat shock test, namely lX-2X; the other ; ~
properties cited above were found to be essentially unchanged. ~ ~ -
`, :'~
. ~
,,
,~
~ 87-
4 'Jj'i, ''` l : . ' ' ' ' ' ' . . "'
()3-Lo-4462
10~9139
ExampleS 36-4?
To a series of polymer blend solutions prepared
by the procedure descrlbed in Example 35, at 32.2% solids
by weight, was added organometallic compounds known to be
accelerators utilized in curing of certain polyesters. The ~ ;
catalysts employed and their concentrations are as
follows (in each instance the percent values are expressed
as percent organometallic by wei~ht of the resin solids):
Example 36. 0.5% Tetraoctylene glycol titanate
(Tyzor OG) ~
Example 37. 1.0% Tetraoctylene glycol titanate ~;
- (Tyzor OG) ;
Example 38. O.5%Triethanolamine titanate --
(Tyzor TE) ;
Example 39. 1.0% Triethanolamine titanate - -
(Tyzor TE)
Example 40. 2.0% Trieth`anolamine titanate
(Tyzor TE)
~ Example 41. O.5% Ammonium salt of kitanium lactate
;~ 20 (Ty~or LA) ,~
Example 42. 2.0% Ammonium salt of titanium lactate
(Tyzor LA) -~
These titanium chelates are commercially available -~
; - from E.I. duPont deNemours & Co. as follows: Tyzor OG at
100% solids; Tyzor TE as 80% solids in isopropanol; Tyzor LA -~
as 50% soIids in water. In each instance the accelerator
was compatible, forming stable, clear solutions with the - ~ ;
Example 35 polymer blend solution. In order to evaluate
the effect of acceleration on the cure, a cut-through test ;~
~ was performed on films cured out employing a standard cure
schedule. The cut-through test~involved formation of a 3.0
mll film on an aluminum substrate which was then shaped over
h~ copper wire and over which was then crossed a ~
~ bare copper wire, perpendioular to the coated substrate. A ~-
1:~ ~: ,
: ~.. ,
, . :~ : ~
~ 88~
n3-Lo-4462
10~9139
1000 g. weight was placed at the cross point and the unit
placed in a forced-air oven. The oven was equipped with
thermocouples and a rate of temperature rise of 3/min.
With the aid of a multipolnt recorder the cut-through
temperature was automatically recorded as that point when
the cured film was cut through and offered no res-istance
to flow of current. The cured film in each case was
prepared by weighing o.8 g. into a 5.5 cm. diameter
aluminum dish and then subjected to a cure schedule of 15
min. at 150 C., 90 min. at 220 C. and 5 min at 255 C.
There resulted clear, tough films exhibiting excellent
adhesion to aluminum. The results of the cut-through test
are presented in the following table~
Sample Catalyst Cut-through
: .
Example 36 Tyzor OG - O.5% 204
Example 37 Tyzor OG - 1.0% 220
Example 38 Tyzor TE - O.5% 224
Example 39 Tyzor TE - 1.0% 253
Example 40 Tyzor TE - 2.0% 270+
Example 41 Tyzor LA - O.5% 222
~; Example 42 Tyzor LA - 2.0% 270+
Example 35 No catalyst 184 (258*) ;~
*A out-through of 258 was achieved when the time
at 255 C. in the cure schedule was extended from
5 min. to 50 min.
: ' '
~ -89-
~::
o3-Ln-l~4~2
1(~85~39
T~le 32.2% solids solution of ~xample 39 containing
1.0% triethanolamine titanate (Tyzor T~) by resin weight,
was employed to coat 18 AWG wire, O.O4O3 inch copper and
aluminum wire using a conventional set of six wire enamel
metering dies and forced-air ovens to cure as described
in Example 35. The resulting films were found to be smooth
and concentric with a 2.8 to 3.0 mil film build on the ~ ~
diameter. The properties of the film included: 25% and ~ `
lX flexibility on copper; 15% and lX flexibility on
aluminum; repeated scrape 18-28 strokes; chemical ;
resi$tance to 70/30 and 50/50 solvent test; dielectric
strength in excess of 2000 v./mil; 2X-3X heat shock at
155 C.; 3X in the 175 C. heat aging.
From the above results of Examples 36 through 42,
as compared to the results of Example 35, it was apparent
that the titanium chelate accelerators offer desirable
acceleration of the cure of coatings applied from the
polyester orthoamic acid diamine aqueous solution blends,
without degradation Or the film properties, and with an
increase in cut-through temperature. -~
.~,
-90-
~ ,. , ,. , , . . . .. ~
o3-r~ 462
1089139
Example 43
To a reactor equipped wlth a heating mantle and a
stirrer and containing 60.5 g. of the polyester resin system
I of Example 21 at 60 C., was trickled in over a period
of 5 min. 14.1 g. of the orthoamic acid diamine solution III
of Example 1, at 50% solids as the orthoamic acld in N-methyl-
2-pyrrolidone, with the reactor temperature controlled at
60 C. and with agitation. The temperature was held at 50 C.
with agitation continuing for an additional period of 10 min.
There resulted a clear polymer blend solution at a solids
level of 90% by weight in N-methyl-2-pyrrolidone (I). To the
reactor was then added with agitation, continuously over a ;
period of 3 min! a mixture of 9.92 g. dimethylethanol amine,
0.72 g. dimethyl amine, 111.7 g. water, O.7 g. N-methyl-2-
pyrrolidone, 10.~ g. n-butyl alcohol, 0.41 g. ethylene
glycol n-butyl ether and sufficient nonylphenolethylene
oxide adduct such that the resulting system had about 60 p.p.m.
of the latter component. There resulted a clear solution wi~th~
no evidence of phase separation. The solution properties of
this polymer blend were as follows: Solids level, 32.1%; -~
surface tension,~36.7 dynes/cm.; pH, 7.6; viscosity 387 cps.
at 24 C. The solvent system is in excess of 80~ water.
;~ These solution properties are not unlike those found for
Example 35. The clarity, toughness, flexibility, and
adhesion properties for films formed in a manner identical
with the procedures cit-ed in Example 35 were essentially
like those found for the alternative polymer blend method
~` of preparation illustrated in Example 35. In essence a
J ~
.,' : ' . ' `
~ - 9 1-
o3-T,o-4462
10~39139
~ .
similar result can be obtained independent of whether the
polymer blending operation is performed before or after the ~ :~
conversion o~ the separate polymers to water soluble
polyelectrolytes. Additional studies indicate that the
normal heat-bodying of a resin-solvent system to provide a
preferred solids-viscosity relationship is best conducted
on the resin blend before the resins have been converted to -
the water soluùle pcIyelectrolyte form,
.
~,''. ~ .
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n3-r.n-4LI62
1089139
Exarnple 44
To a polymer blend solution prepared as described in
Example 43, at a solids level of 32.1~, was added 1.0%
triethanolamine titanate by weight of resin solids. There
resulted a clear stable solution at abou~ 32.1% solids,
with solution properties similar to those cited in
Example 43. About o.8 g. of the solution was placed in
an aluminum dish 5.5 cm. in diameter. The sample flowed
out evenly and was cured using a stepwise cure of 15 min.
at 150 C., 90 min. at 220 C., and 5 Min. at 255 C.
There resulted a clear, flexible, tough film exhibiting excellent
adhesion to aluminum. A strip of coated aluminum containing
3.0 mil of the so-cured film was tested versus a similarly
prepared film of Example 43 in the cut-through apparatus
described in Examples 36-42 and found to have a cut-through
of 256 C. as compared to a cut-through of 187 C. observed
in Example 43. This example illustrates, as was found in
Examples 36-42, that titanium chelates offer a desirable
acceleration of the cure of the plYeSter~orthoamide acid
diamine aqueous solution blend. . ~-
';
: .
-::
:"'
'
-93-
o3-Lo-4462
10~13'~ ~ ~
.:
Example 45
To 74.6 g. of the polymer blend solution prepared
according to Example 43 solution I, at about 90% solids
by weight, in N-methyl-2-pyrrolidone, was added 1%
triethanolamine titanium chelate by weight of resin solids
with the polymer blend solution at about 55 C. with
agitation and with agitation continuing for about 10 min. ;
after the addition. To the reactor was then added, with
agitation, continuously over a period of 3 min., a mixture
of 9.92 g. dimethylethanol amine, 0.72 g. dimethylamine,
111.7 g. water, O.7 g. N-methyl-2-pyrrolidone, 10.9 g. n-
butyl alcohol, 0.41 g. ethylene glycol n-butyl ether and ~`
sufficient nonylphenolethylene oxide adduct such that the
resulting system had about 60 p.p.m. of the latter
component. There resulted a clear stable solution at 32.1%
solids with solution properties similar to those cited in
Examples 43 and 44. About O.8 g. of the solution was ``~
placed in an aluminum dish 5.5 cm. in diameter. The sample
flowed out evenly and was cured usin~ a stepwise cure of
15 min. at 150 C., 90 min. at 220 C., and 5 min. at 255 C. -~
There resulted a clear, flexible, tough film exhibiting
excellent adhesion to the aluminum substrate. A strip of
coated aluminum containing 3.0 mil of the so-cured film was
~- tested in the cut-through apparatus described in Examples ~ ;~
25 ~ 36-42 and found to have a cut-through of 264 C. As was
found in Examples 36-42, titanium chelates offer a desirable
, ,; ~ ;,
acceleration of the cure of the polyester orthoamic acid -~
diamine aqueous solution blends, and, furthermore, similar
. .'- . .
_94_
, . _ , , . _ . _ _ _ . , . , . _ . , , . .. , , _, ................. . .
o3-Lo-4462
1085~139
results can be obtained independent of whether the polymer
blending operation is performed before or after the
conversion of the separate polymers to water soluble
polyelectrolytes. Additional studies indicate that the
normal heat-bodying of a resin-solvent system to provide
a preferred solids-viscosity relationship is best conducted
on the resin blend with accelerator included before the ~ .
resins have been converted to the water soluble polyelectrolyte
form.
~,
': ~
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,
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" .~, . . . .
03-Lo-4462
101~9133
Examples 46-53
In a manner similar to that described in
Example 35, a series of 9/1=ester/orthoamic acid diamine
solution blends were prepared using 180.0 g. of each of
the polyesiers prepared as described in Examples 14-22,
at solids levels ranging from 33.9 to 34.6%, and 18.8 g.
of the orthoamic acid diamine prepared as described in
Example 1, at 36.o% solids (as the cured film) as follows:
Example 46. 180.0 g. polyester of Example 14 + 18.8 g.
orthoamic acid diamine of Example 1
Example 47 180.0 g. polyester of Example 15 + 18.8 g.
orthoamic acid diamine of Example 1
Example 48. 180.0 g. polyester of Example 16 + 18.8 g.
orthoamic acid diamine of Example 1 ~
Example 49. 180~0 g. polyester of Example 17 + 18.8 g. ~-
orthoamic acid diamine of Example 1 ~-
Example- 50. 180.0 g. polyester of Example 18 ~ 18.8 g.
orthoamic acid diamine of Example 1
Example 51. 180.0 g. polyester of Example 19 + 18.8 g.
orthoamic acid diamine of Example 1
Example 52. 180.0 g. polyester of Example 20 + 18.8 g.
orthoamic acid diamine of Example 1
Example 53. 180.0 g. polyester of Example 22 + 18.8 g.
orthoamic acid diamine of Example 1
-~ 25 In each instance, the polyester was compatible -
with the orthoamic acid diamine, unlike the results found ~;
ln Examples 24-34. In each instance, the blend was treated
with a mixture of n-butyl alcohol, N-methyl-2-pyrrolidone, and
the nonionic wetting agent as described in Example 35. The
-
resulting clear solutions of polymer blends had a solids ` ;~
level ranging from 32 to 34%, a viscosity in the range of
260-480 cps., a pH range of 7.4-7.8, a surface tension in
the range of 36.4-37.5 dynes/cm. and a solvent in the range
of 80.0% by weight water. About 0.5 g. of each solution
was placed in an aluminum dish about 5.5 cm. in diameter.
:
,
~ . ~ ' ' ' , "~.
-96- ~
... .. . . . . . , , , . . - . ~ .
o3-L()-4462
108~139
The solutions flo~cd out evenly. The samples were placed
in a forced-air oven set at 150 C. for 15 min. and then
removed and examined. A11 films were found to be homogeneous,
clear, and free of any phase separation. The cure was
continued for 90 min. at 220 C. followed by 20 min. at
250 C. There resulted clear, tough 0.3-1.0 mil films
exhibiting excellent adhesion to and flexibility on the
aluminum substrate in every case. Another portion of each
solution was placed on a copper substrate and another on an
iron substrate and a doctor blade employed to draw uniform
wet fllms. A similar cure schedule was employed and the
resulting 0.2-0.5 mil films were found to be clear, tough
and exhibiting excellent adhesion to the substrate as
evidenced by no separation at the interface following
considerable flexing in every case.
'' -'
~ . .
: . .
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~ ' ' .
.
-97-
03~ -4462
lU89 1 3
Example 54--56
. .
In a manner similar to that employed in Example 35
a series of aqueous polymer solution blends were attempted
using 180.0 g. Or the aqueous 33. 6 solids polyester solution
prepared as described in Example 21, and a quantity of each
of the aqueous orthoamic acid diamine solution prepared as
described in Examples 2-5, such that the polyester to
orthoamic acid diamine ratio was 9/1 by weight, as follows:
Example 54 180.0 g polyester solution of Example 21
18.8 g. diamide-diacid-diamine solution
Or Example 2. -~
Rxample 55 180.0 g. polyester solution of Example 21 + ~ ~-
27. 8 g. diamide-diacid-diamine solution
of Example 4. ~ -
Rxample 56 180.0 g. polyester solution of Example 21 + ~ ~
26. 2 g. diamide-diacid-diamine solution --
of Example 5.
In sharp contrast to the results of Examples 28-34 in which
a phase separation was obtained with a polyorthoamic acid
~ 20 polymer rich layer and a polyester polymer rich layer,
`~ clear solutions were obtained in each of Examples 54-56.
~ Applying a cure schedule of 15 min. at 150C., go min. at
220C., 20 min. at 250OC. to about 0.5 g. of wet drawn film,
there resulted homogeneous clear, tough 0.3-1.0 mil films
exhibiting excellent adhesion and flexibility on aluminum,
iron and copper substrates.
:
98
o3-r,()-~ 6~
1089~;~9
Tc a reactor equipped with a stirrer was charged
180.0 g. of a polyester at 33.6% solids prepared as described
in Example 21 followed by 26.3 g. of the orthoamic acld
diamine prepared as described in Fxample 3 at 25.6% solids
(as the imide). Stirring was continued for a period of 15
min. The resin ratio of polyester to orthoamic acid diamine
was at about 9/1. In sharp contrast to the result of Example
24 there resulted a clear solution with no evidence of phase
separation. To the reactor with agitation was added 10.0 g.
of a mixture of 9.5 g. n-butyl alcohol and 0.5 g. N-methyl-2-
pyrrolidone containing a sufficient amount of nonylphenol-
ethylene oxide adduct such that the resulting system had about ~ -
60 p.p.m. Or the latter component. The resulting clear
highly aqueous solution of the polymer blend had a solids
level of 30.1%, a surface tension of 36.2 dynes/cm., a pH
of 7.3 and a viscosity of 323 cps. at 24C. The solvent in
this system was in excess of 77% water. About 0.5 g. of the
solution was placed in an aluminum dish about 5.5 cm. in
diameter. The solution flowed out evenly. The sample -
was given a cure schedule of 150C. for 15 min., 90 min. at
220C., and 20 min. at 250C. There resulted a clear, tough
0.3-1.0 mil film, exhibiting excellent adhesion to and flexi-
bility on the aluminum substrate. Another portion of the
solution was placed on a copper substrate and another on an
iron substrate and a doctor blade employed to draw uniform
wet films. A similar cure schedule was employed and the
resulting 0.2-0.5 mil films were found to be clear, tough, -
and exhibitin~ excellent adhesion to the substrates as evidenced
~ 3 by no separation at the interface following considerable flexing.
., :
: :
~ ~ , ,, , , ~ .' :
~3~ 4462
108913~
The 31.1% solids solution was employed to cost 18
AWG wire, 0.0403 inch, copper and aluminum, using a conventional
set of six wire enamel meterin~ dies, namely, 0.043, o.o44,
0,044, 0.045, o.o45 and o.o46 inch diameter opening. Each
of the wet drawn films was cured with the aid of forced-air
ovens before the next layer of wet film was applied. The -
resulting films were smooth and concentric. The film build
was 2.8 to 3.0 mil on the diameter. A description of the -~
mechanical, chemical, electrical and thermal test methods have
been presented above. Properties of the film included~
25% and lX flexibility on copper; 15% and lX flexibility on
aluminum; repeated scrape of 18-30 strokes; resistance to
~:.' . ,',: '
70/30 and 50/50 solvent; greater than 2000 v./mil; dielectric
strength; 2X-3X in 155 heat shock; 2X-3X in 175C. heat aging. ~- ~
~ 15 To the 31.1% solids polymer blend aqueous solution ~ .
;; was added 1.0% triethanolamine titanium chelate by resin
weight and the resulting clear solution was used to coat 18
AWG wire, copper and aluminum, using the conventional set of
six wire enamel metering dies and forced-air oven cure as
cited above. The resulting films were smooth and concentric.
The film build was 2.8-3 .0 mil on the diameter. Properties
of the film included 25% and lX flexibility on copper; 15%
and lX flexibi1ity on aluminum; repeated scrape of 17-31 - -
strokes; resistance to 70/30 and 50/50 solvent; dielectric
strength in excess of 2000 v./mil; 2X-3x in the 155C. heat ` ;~
shock; 2X-3X in 175c. heat aging. No degradation of properties
.,
by inclusion of the accelerator was observed.
The SlX pass coated wire was overcoated with a
conventional nylon wire enamel, namely, a 15% 6,6-Nylon
` :'
': ' '
,,,
`~ -100-
~3-L~-4462
108~39
dissolved in 70/30 cresylic acid/hydrocarbon solvent. This
was accomplished with an O.Oll7 inch diameter die opening for
the seventh pass. The wet drawn nylon film was cured with
the aid of forced air ovens. The resulting film composite
was smooth. A slight improvement was found in the heat
shock test, namely, lX-2X; the other properties cited above -~
were found to be essentially unchanged.
, : '.'
.: '
- 1 0 1-
o3-Lo-4462
~1)89i39
Example 58
To a reactor equipped with a stirrer was charged -
100 0 g. of a polyester at 33.6% solids prepared as described
in Example 21 followed by 17.2 g. of the orthoamic acid diamine
prepared as described in Example 8 at 21.7% solids (as the -
cured film). Stirring was continued for a period of 15 min. ;~
The resin ratio of polyester to orthoamic acid diamine was
at about 9/1. In sharp contrast to the result of Example 24,
there resulted a clear solution with no evidence of phase
separation. To the reactor, with agitation, was added 5.0 -~
g. of a mixture of 4.5 g. n-butyl alcohol and 0.5 g. N-methyl-2-
pyrrolidone containing a sufficient amount of a nonylphenol- -~
ethylene oxide adduct such that the resulting system had about
60 p.p.m. of the latter component. About 0.5 g. of the solution ~-
~- 15 was placed in an aluminum dish about 5.5 cm. in diameter.
The solution flowed out evenly. The sample was placed in a
forced-air oven set at 150C. for 15 min. and then removed -~
and examined. It was found to be a homogeneous clear film
free of any phase separation. The cure was-continued for 90
min. at 220C. followed by 20 min. at 250C. There resulted
a clear, tough 0.3-1.0 mil film exhibiting excellent adhesion - . - ;
to and flexibility-on the aluminum substrate. Another portion
of the solution;was placed on a copper substrate and another
on an iron substrate and a doctor blade employed to draw
uniform wet films. A similar cure schedule was employed and ~-
the resulting 0.2-~0.5 mil films were found to be clear,
tough, and exhibiting excellent adhesion to the substrates ~-
- ~ as evidenced by no separation at the interface following `~
~ ~ :
~ considerable flexing.
::
-102-
.": .-,, . ~ .
n3-l.0-4462
1C)~3~139
Examples 59-63
In a manner similar to that utilized in Example 58, ~;
a se~ies Or polymer solution blends were attempted using
100.0 g. of a polyester at 33.6% solids prepared as described
in Example 21 and an appropriate amount Or the orthoamic
acid diamines described in Examples 9-13, in order to provide ~ ~-
a 9/1=polyester to orthoamic acid diamine blend as rOllows:
Example 59. 100.0 g. polyester of Example 21 + 17.8 g.
orthoamic acid diamine of Example 9.
Example 60. 100.0 g. polyester of Example 21 + 17.2 g. - -- -~
orthoamic acid diamine of Example 10.
Example 61. 100.0 g. polyester of Example 21 + 22.5 g.
orthoamic acid diamine of Example 11. -~
Example 62. 100.0 g. polyester of Example 21 + 23.9 g. ~ - -
orthoamic acid diamine of Example 12.
Example 63. 100.0 g. polyester of Example 21 + 24.5 g.
orthoamic acid diamine of Example 13.
As in Example 58, and in sharp contrast to the results of
.
Examples 24-34 where phase separations occurred resulting in
polyester-rich and polyimide prepolymer-rich layers, clear
solutions were obtained in Examples 58-63. As in Example
.: ~
5&,~ each Or the solutions in Examples 59-63 was treated wlth
a mixture of n-butyl alcohol and N-methyl-2-pyrrolidone -
(at 5.0 g.ilOO g. polyester solution) and a nonionic
;25 surfactant. Applying a cure schedule of 15 min. at 150C., -
90 min. at 220C., and 20 min. at 255C. to wet drawn films,
there resulted homogeneous clear, tough 0.3-1.0 mil films
exhibiting excellent adhesion and flexibility on aluminum,
iron and copper substrates in all cases.
:
il~J~'~l3~3 03-LO-4462
Exampl~ 64 ~
To the polymer blend of Example 59 and 30.5% solids, ,, , ~ ,
which in turn employed the polyester of Example 21 and the
M(AM)XAM orthoamic acid diamine of Example 9 where x=3, ~-'
was added 1% triethanolamine titanium chelate by weight of ; ~ '
resin solids. About o .8 g. was placed in an aluminum dish ' -
5.5 cm. in diameter. The sample flowed out evenly ,and was ~-
cured using a stepwise cure of 15 min. at lsoc., 90 min. at ',~ ; ',
220C,, and 5 min. at 2ssc . There resulted a clear, flexible,
tough film exhibiting excellent adhesion to the aluminum
substrate. A strip of coated aluminum containing 3. o mil of the ~'
cured film was tested and compared ~o a similarly prepared film
of Exam,ple 59 in the cut-through apparatus described in Examples
~ : .
36-42, and found to have a cut-through of 24gc. as compared to a
cut-through of 179C. for Example 59 where no accelerator was
~; employed. When the time in the cure schedule for Example 59 ,~
. ~ .
~ was extended from 5 min. at 2ssc. to 50 min. at 2ssc. ~ the ,`~ cut-through was 24sc. for Example 59.
The 30.5% solids solution with the 1.0% accelerator was
employed to coat 18 AWG wire, 0.0403 inch, copper and aluminum,
using a conventional set of six wire enamel metering dies and
cured with the aid of forced-air ovens as described in Example 57. ''~
The~resulting films were smooth and concentric. The film build was
2,8-3.0 mil on the diameter. Properties o~ the film included~
25% and lX flexibility on copper; 15% and lX flexibility on aluminum~
70~30 and 50/50 solvent resistance; greater than 2000 v./mil di~
- electric strength; 2x-3x 155C. heat shock; 2x-3x 175C. heat aging.;'
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o3-Lo-44~s2
1089139
The six pass coated wire was given a seventh
"overcoat" treatment with conventional Nylon wire enamel
as described in Example 57. A11 properties were found to be
essentially unchanged with exception of heat shock which
showed a slight improvement to lX-2X.
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1089139
Example 65
To the polymer blend of Example 62 at 29.0% solids~
which in turn employed the polyester of Example 21 and the
M~BM)XBM of Example 12 where x=3, was added 1% triethanolamine
titanium chelate by weight of resin solids. About 0. 5 g. was
placed in an aluminum dish 5.5 cm. in diameter. The sample
flowed out evenly and was cured, using a stepwise cure of
15 min. at 150C., 90 min. at 220c., and 5 min. at ~55C.
There resulted a clear, tough, flexible 0.2-0.8 mil film
exhibiting excellent adhesion to the aluminum substrate. With
the aid of a doctor blade wet films were drawn on copper and
iron substrates. A similar cure schedule was applied
resulting in 0. 2-0.5 mil clear films exhibiting excellent
adhesion to the substrates as evidènced by no separation at ;~
the interface following considerable flexing. A 1.0 g. sample
was placed in the aluminum dish and the above cure applied
to form a 3.0 mil film. Using the cut-through apparatus
described~in Examples 36-42, the cured film was found to have
a cut-through of 254c. as compared to a cut-through of 182C.
for a similarly prepared film of Example 62 where no accelerator
was employed. When the time in the cure schedule of F.xample
62 was extended from 5 min. at 255C. to 50 min. at 255C.,
the cut-through was 247C. for Example 62. ~
The 29. 0% solids solution with the 1.0% accelerator ~-
~25 was employed to coat 18 AWG wire, o.o403 inch, copper and ---
aluminum, using a conventional set of six wire enamel metering
dies and cured with the aid of forced-air ovens as described
in EXample 57. The resulting films were-smooth and concentric.
The film build was 2.8-3.0 mil on the diameter. Properties
,: ~
~3 of the film included: 25% and lX elongation on copper; 15%
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and lX elon~,ation on aluminum; 70/30 and 50/50 solvent
resistance; dielectric strength in excess of 2000 v./mll;
2X-3X 155C. heat shock resistance; 2X-3X performance in the
175C. heat agin~ test.
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Example 66
To a reactor, equipped with a stirrer, was charged
180.0 g. of the aqueous orthoamic acid diamine solution pre- ~ ;
pared as described in Example 1 at 36.o% solids (as the cured
film), followed by 20.0 g. of an aqueous 33.6% solids polyester
solution prepared as described in Example 21.
Stirring was continued for a period of 15 min.
The ratio of polyester to orthoamic acid diamine was at about
1/9 b~ weight. There resulted a clear solution with no
evidence of phase separation. The solution was metered
onto aluminum, iron and copper substrates with the aid of
a doctor blade. The samples were placed in a forced-air oven
:et for a cure schedule of 15 min. at 150C., 90 min. at 220C.,
~ and 60 min. at 250C. In each instance there resulted tough,
- 15 clear 0.2-0.5 mil films exhibiting excellent adhesion and ~
~ ~ ~ " -:
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Example 67
The procedure described in Example 66 was repeated
with the exception that an equal weight of the orthoamic
acid diamine solution and of the polyester were employed,
resulting in a resin ratio of about one-to-one by weight.
There resulted a clear solution, with no evidence of phase
separation. The same procedure of film formation and cure
was employed on the three cited substrates. In each instance,
there resulted tough, clear, films exhibiting excellent
adhesion and flexibility.
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Example 68
To a reactor, equipped with a stirrer, was charged
180.0 g. of the aqueous 33.6% solids polyester solution
prepared as described in Example 21, followed by 16.0 g.
of the aqueous 36.0% solids (cured) orthoamic acid diamine
solution prepared as described in Example 1. Stirring was
continued for a period of 15 min. With stirring, 4.0 g. of
a 35.0% solids aqueous solution of a low viscosity, liquid,
phenolic resin, commercially available as BRLA 2854 from
Union Carbide Corporation, was added over a period of 2 min., ;~
and the stirring continued for another 15 min. There
resulted a clear solution. The resulting solids ratio was
i~ about 9o/2/8, i.e., polyester/phenolic/orthoamic acid diamine.
~; The solution was metered onto aluminum, iron and copper sub- -
strates with the aid of a doctor blade. The samples were
placed in forced-air ovens set for a cure schedule of 15
min. at 150C., 90 min. at 220C. and 60 min. at 250C. ;
There resulted clear, tough, 0.2-0 5 mil films exhibiting
excellent adhesion and flexibility on all three substrates.
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9139
Exam ~
To a reactor, equipped with a stirrer was charged
180.0 g. Or the aqueous 33.6% solids polyester solution
prepared as described in Example 21, followed by 10.0 g.
of the aqueous 36.o% solids orthoamic acid diamine solution
prepared as described in Example 1. After about 15 min.
of stirring, 10.0 g. of B~LA 2854 (see Example 68) was
trickled in over a 2 min. period and stirring was
continued for an additional 15 min. 1'here resulted a
clear solution with a solids ratio of about 90/5/5, i.e.,
polyester/phenolic/orthoamic acid diamine. With the aid ~ -
of a doctor blade and following curing in forced-air
ovens as described in Example 68, there resulted clear,
~ j -
. . .
tough, 0.2-0.5 mil films exhibiting excellent adhesion ~ ~
.,
and flexibility on aluminum, iron and copper.
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lU89139
Example 70 ;-
To a reactor, equipped with a stirrer, was
charged 180.0 g~ of the aqueous, 33.6% solids polyester
solution prepared as described in Example 21, followed
by 16.0 g. of the aqueous 36.0% solids orthoamic acid
diamine solution prepared as described ln Example 1.
Stirring was continued for a period of 15 min. With
stirring, 4.0 g. of a 35.0% solids 80/20 aqueous
alcoholic solution of a commercial grade of
hexamethoxymethylmelamine, aminoplast resin, such as
Cymel 301 from American Cyanamid Company, was trickled
in with stirring over a period of 2 min. The stirring was
,
~; continued for an additional 15 min. The resulting resin
solids ratio was about 90/2/8, i.e., polyester/aminoplast/
orthoamic acid diamine. With the aid of a~doctor blade
and following curing in the forced-air ovens as described
in example 68, there resulted clear, tough, 0.2-0;.5 mil
~films exhibiting excellent adhesion and flexibility on
aluminum, iron and copper.
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Example 71
To a reactor equipped with a stirrer was charged ;
180.0 g. of the polyester at 33.6% solids prepared as described
in Example 15 followed by 10.0 g. of the orthoamic acid
diamine prepared as described in Example 1 at 36.0% solids.
After 15 min. of stirring, 10.0 g. of Cymel 301 (see Example
70) was trickled in with stirring over 2 min. and the stirring
continued for an additional 15 min. mhere resulted a clear
solution with a resin ratio of about 90/5/5, i.e., polyester/ -~
aminoplast /orthoamic acid diamine. With the aid of a doctor
blade and forced air ovens and a cure schedule as described ~ `
in Example 70, there resulted clear, tough 0.2-0.5 mil films
exhibiting excellent adhesion and flexibility on aluminum,
iron and copper.
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Fxample 72
To a reactor, equipped with a stirrer, was charged
180.0 g. of the aqueous 33.6% solids polyester solution
prepared as described in Example 21, followed by 16.0 g. of
the aqueous 36.o% solids orthoamic acid diamine solution
prepared as described in Example 1. Stirring was
continued for a period Or 15 min. Wlth stirring, 4.0 g.
of a 35.0% solids water soluble epoxy resin, such as
Araldite DP-630 from Ciba-Geigy Corporation, was trickled
in, with stirring, over a period of 2 min. The stirring
was continued for an additional 15 min. The resulting resin
solids ratio was about 90/2/8, i.e., polyester/expoy/
orthoamic acid diamine. The solution was metered onto
aluminum, iron and copper substrates with the aid of a
doctor blade. The samples were placed in forced-air
ovens for a cure schedule of 15 min. at 150C., 90 min.
at 220C. and 20 min. at 250C. There resulted clear,
tough, 0.2-0.5 mil films exhibiting excellent adhesion `
and flexibility on all three substrates.
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03-LO-4462
108'3139
:
Example 73
To a reactor, equipped with a stirrer, was charged
180.0 g. of the aqueous 33.6% solids polyester solution
prepared as described in Example 21, followed by 10.0 g.
of the aqueous 36.0~ solids orthoamic acid diamine
solution prepared as described in Example 1. After 15 min.
of stirring, lOg of Araldite~ DP 630 was trickled in, with stirring, over ~ -
2 minutes, and the stirring continued for an additional
15 min. There resulted a clear solution with a solids
ratio of about 90/5/5, i.e., polyester/epoxy/orthoamic acid ``~
diamine. With the aid of a doctor blade and following the ;
forced-air oven cure schedule described in Example 68,
., ~: ,,
there resulted clear, tough, 0.2-0.5 mil films exhibiting
excellent adhesion and flexibility on aluminum, iron and
~15 copper.
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1089139
Examp~e 74
To a reactor equipped with a stirrer was charged
180.0 g. of the polyester at 33.6% solids prepared as described
in Example 14, l~ollowed by 18.9 g. of the orthoamic acid
diamine prepared as described in Example 3 at 28.4% solids
(as the cured film). Stirring was continued for 15 min.
With stirring, 3.8LI g. of a 35.0% solids aqueous solution of
a low viscosity liquid phenolic resin, commercially available
as BRL 1031 from Union Carbide Corporation, was added over
a period of 2 min., and the stirring continued for another
15 min. The resulting homogeneous, clear, solution had a
resin ratio of polyester/phenolic/orthoamic acid diamine '~
of about 90/2/8. To the reactor, with agitation, was added
10.0 g. of a mixture of 9.5 g. n-butyl alcohol and 0.5 g. N-
methyl-2-pyrrolidone containing a suff'icient amount of nonyl-
phenolethylene oxide adduct such that the resulting system
had about 60 p.p.m. of the latter component. The resulting
clear aqueous solution of the polymer blend had a solids
level of 31.6%, a surface tension of 36.2 dynes/cm., a pH ~
of 7.4 and a viscosity of 377 cps. at 24C. The solvent in ;
this system was in excess of 80% water. The solution was
metered onto aluminum, copper and iron substrates with the ~ '
.
aid of a doctor blade. The samples were placed in forced-
air ovens set for a cure schedule of 15 min. at 150C., 90 min.
at 220C., and 20 min. at 250C. There resulted clear, tough
0.2-0.5 mil films exhibiting excellent adhesion and flexibility
on all three substrates as evidenced by no separation at the '~
interface following considerable flexing.
.~- - ~ .
The 31.6% solids solution was employed to coat 18
3 AWG wire, 0.01l03 inch, copper and aluminum, using a conventional
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-116-
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o3-L~-4462
1()89139
set Or six wire enamel metering dies and cured with the
aid of rorced-air ovens as described in Example 57. The
resulting films were smooth and concentric, the film build ; -
was 2,8 to 3.0 mil on the diameter. Properties of the film
included: 25% and lX-2X flexibility on copper; 15% and lX
flexibility on aluminum; 70/30 and 50/50 solvent resistance;
dielectric strength in excess of 2000 v./mil; 2X-3X heat
shock in the 155C. test; 2X-3X in the 175C. heat aging test.
To the 31.5% solids polymer blend aqueous solution
was added 1% ammonium lactate titanium chelate by resin
weight~ and the resulting clear solution was used to coat
18 AWG wire, copper and aluminum, using the conventional
set of six wire enamel metering dies and forced-air oven cure -
as cited above. The resulting films were smooth and con-
; centric. The film build was 2.8-3.0 mil on the diameter.
Properties of the film included: 25% and lX-2X flexibility
on copper; 15% and lX on aluminum; 70/30 and 50/50 solvent
resistance; dielectric strength in excess of 2000 v./mil;
2X-3X 155C. heat shock; 2X-3X 175C. heat aging.
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10~9139
Example 75
To a reactor equipped with a stirrer was charged 180.0 g.
of the polyester prepared as described in Example 17 at 3~.2~
solids followed by 21.0 g. of the orthoamic acid diamine prepared
as described in Example 7 at 26.1% solids (as the cured film).
After 15 min. of additional stirring, 3.91 g. of a 35.0% 80/20
aqueous alcoholic solution of hexamethoxymethylmelamine, (Cymel `~
301, from American Cyanamid Company), was trickled in with stirring
over a period of 2 min. The stirring was continued for an additional
15 min. The resulting resin blend ratio was about 90/2/8, i.e.,
polyester/"aminoplast"/orthoamic acid diamine. To the reactor,
with agitation, was added 10.0 g. of a mixture of 9.5 g. n-butyl
alcohol and 0.5 g. N-methyl-2-pyrrolidone containing a sufficient
amount of nonylphenolethylene oxide adduct such that the resulting
system had about 60 p.p.m. of the latter component. The resulting
clear aqueous solution of the polymer blend had a solids level of
31.8%, a surface tension of 35.8 dynes/cm., a pH of 7.4 and a
viscosity of 416 cps. at 24C. The solvent in this system was in
excess of 80% water. The solution was metered onto aluminum,
copper and iron substrates with the aid of a doctor blade. The ~ `
samples were placed in forced air ovens set for a cure schedule of :
15 min. at 150C., 90 min. at 220C. and 20 min. at 250C. There ~
resulted clear, tough 0.2-0.5 mil films exhibiting excellent adhes- -
ion and flexibility on all three substrates. - ;
The 31.8% solids solution was employed to coat 18 AWG wire,
0.0403 inch, copper and aluminum, using a conventional set of
six wire enamel metering dies and cured with the aid of ~
' forced-air ovens as per Example 57. The resulting films ~ -
- 118 -
. ~ . .. ... . . . .
~89139 03-Lo-lJ462
were at a 2.8-3.0 mil build on the diameter and were found
to be smooth and concentric. Properties of the film included: ~
25% and lX-2X flexibility on copper; 15% and lX on aluminum; . ~-
70/30 and 50/50 solvent resistance; greater than 2000 v./mil
dielectric strength in the twisted pair test; 2X-3X heat
shock in the 155C. test; 2X-3X in the 175C. heat aging
test. ;~
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~089139
l~lh:lle certain illustrative emhodiments and
modifications Or the present invention have been described
in considerable detail, it should be understood that
there is no intention to limit the invention to the
specific forms disclosed. ~n the contrar~, the
intention is to cover all embodiments, modificat~on,
alternatives, equivalents and uses fallin~ within the
spirit and scope of the invention as ex~ressed in the
appended claims.
I claim as my invention:
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