Note: Descriptions are shown in the official language in which they were submitted.
2 7 ~o3981
LeA 29,436 -us
AMINO-FUNCTIONAL POLYESTER RESINS
BACKGROUND OF THE INVENTION
Field of the Invention
The present invention relates to a new process for the production
of amino-functional and optionally hydroxy-functional polyester resins, to
the resins obtained by this process and to their use as a binder
component in two-component polyurethane coating compositions.
Descriotion of the Prior Art
Two-component polyurethane coating compositions are known and
are suitable for the production of high-quality coatings which can be
made hard, elastic, abrasion resistant, solvent resistant and, above all,
weather resistant. The basic chemistry of these lacquers and coatings is
described inter alia in "Lackkunstharze", Hans-Wagner/Hans Friedrich
Sarx, Carl Hanser Verlag, Munchen, pages 153 to 173 (1971). The
polyesters described as resin component almost exclusively contain
hydroxyl groups which react with the polyisocyanates used as curing -~
agents to form polyurethanes.
The reaction between the OH and NCO groups proceeds so slowly
at room temperature that economical, i.e., rapid, drying is only possible at
elevated temperatures. Although the relatively slow reaction at room --
temperature can be accelerated by catalysts, the resulting coatings are
adversely affected, for example, in their hardness, by the catalysts used -
(S. Gunther, Ind. Lackierbetr. 57 (1989), No. 5, page 167).
The possibility of using the very much faster reaction between
aliphatic amines and isocyanates has not satisfactorily been used in
practice due to the extremely high reaction rate which prevents a
controlled reaction. The fairly sluggishly reacting aromatic amines cannot
be used for top coats due to their pronounced tendency towards -
30 yellowing.
35376TWR3006
'' ~',:
.
2 7
EP-A-0,403,921 describes a simple process for reducing the
excessive reactivity of aliphatic amines. This process is based on the
addition of primary amines onto maleic acid esters which gives
secondary amino groups that react with isocyanate groups in the coating
5 system. The main concern of this process was the presence of low
molecular weight, low-viscosity aminic chain-extending agents for two-
component polyurethane coating compositions.
It has now been found that relatively high molecular weight
polyester resins, which, in addition to the optional presence of alcoholic
10 hydroxyl groups, are distinguished by a readily adjustable and
controllable content of primary or secondary amino groups incorporated
in the a-position to the ester groups, are particularly valuable binder
components for two-component polyurethane coating compositions.
These amino-functional polyester resins are produced by addition of
15 ammonia or primary monoamines onto polyester resins containing
olefinically unsaturated structural units of the type described in more
detail hereinafter to form primary or secondary amino groups.
Although the production of amino-functional polyester resins by
addition of amine onto unsaturated polyester polyols is already known
20 from EP-A-0,273,243, the amines mentioned there as starting material
are diamines containing two primary amino groups. The products of this
reference are distinguishable from the products of the present invention,
which are described in detail hereinafter, in particular by the presence of
primary amino groups which are not arranged in the a-position to the
25 ester groups (referred to in the Examples as "basic nitrogen") and which
therefore show a reactivity to isocyanate groups which is much higher
than that of the amino groups present in the end products according to
the invention. In addition, the end products of the reference are not
Mo3981
~3~ 2,111927
recommended as a binder component for two-component polyurethane
coating compositions, but instead for the production of adhesives and
foams.
SUMMARY OF THE INVENTION
The present invention relates to a process for the production of
polyester resins containing 0 to 10% by weight of hydroxyl groups and
0.01 to 9%, preferably 0.05 to 2%, by weight of nitrogen (expressed as ~ -
N = 14) in the form of primary and/or secondary amino groups, -
characterized by reacting in an addition reaction at 0 to 120C
i) polyester resins having a molecular weight (Mn of 286 to 10,û00
and containing an average per molecule of at least 2 structural
units corresponding to the formula: -
~,
O O -:
--O C CH=CH C O-- -
: ~ ................................................... ................................. :,:
and optionally alcoholic hydroxyl groups with
ii) ammonia or primary monoamines corresponding to the formula~
. ~
R-NH2
wherein
R represents an aliphatic, cycloaliphaticoraraliphaticradical ;~
optionally contalning ether oxygen atoms andlor hydroxyl groups.
The present invention also relates to the amino-functional and
25 optionally hydroxy-functional polyester resins obtained by this process
and to their use as a binder component in two-component polyurethane
coating compositions, particularly for coating plastic moldings.
"~',
:
Mo3981
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2 ~
DETAILED DESCRIPTION OF THE INVENTION
The olefinically unsaturated polyester resins used in the process
according to the invention generally have an acid value below 10,
preferably below 3 mg KOH/g; a hydroxyl value of 0 to 325, preferably 0
to 250 mg KOH/g, which corresponds to a hydroxyl group content of 0 to
10%, preferably 0 to 7% by weight; a molecular weight (Mn~ which may
be calculated from the stoichiometry of the starting materials) of 286 to
10,000, preferably 488 to 8,000; and an average of at least 2, preferably
at least 3, structural units corresponding to the formula:
1 1l
--O--C--CH=CH C O--.
In a preferred embodiment, the unsaturated polyester resins are
produced by esterifying ~ .
a) a polycarboxylic acid component containing maleic acid, maleic
anhydride and/or fumaric acid, and optionally up to 95 carboxyl :
equivalent-%, based on the total equivalents of component (a), of
other polycarboxylic acids having a molecular weight of 118 to
1,000, preferably of 118 to 400 and/or anhydrides of such acids
with
b) a polyol component having an maximum average hydroxyl
functionality of 3 and containing at least one polyhydric alcohol
having a molecular weight of 62 to 400 and - .
c) optionally a monocarboxylic acid component in a quantity of up to ~ .
50 carboxyl equivalent-%, based on the total equivalents of :
components a) and c), and containing at least one monocarboxylic -~
acid having a molecular weight of 60 to 400 and/or at least one
Mo3981
5 ~ 7
anhydride of such monocarboxylic acids and
d) optionally a monohydric alcohol component in a quantity of up to
50 hydroxyl equivalent-%, based on the total equivalents of
components b) and d), and containing at least one monohydric
alcohol having a molecular weight of 32 to 400,
while maintaining an equivalent ratio of carboxyl groups to hydroxyl
groups of 1:1.5 to 1:1 and terminating the reaction when the acid value is
below 10 mg KOH/g.
Suitable polycarboxylic acids or polycarboxylic anhydrides a) other
than those mentioned include succinic acid, glutaric acid, adipic acid,
isophthalic acid, phthalic acid, terephthalic acid, phthalic anhydride,
tetrahydrophthalic acid, tetrahydrophthalic anhydride, hexahydrophthalic
acid, hexahydrophthalic anhydride, trimesic acid, trimellitic acid,
commercial dimer or trimer fatty acids and trimellitic anhydride. Adipic
acid is particularly preferred as the other acid a).
Suitable polyhydric alcohols b) include ethylene glycol, 1,2- and
1,3-propanediol, 1,2- and 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol,
neopentyl glycol (2,2-dimethyl-1,3-propanediol), 1,4-bis-(hydroxymethyl)-
cyclo- hexane, cyclohexane-1,2- and -1,4-diol, 2,2-bis-(4-hydroxy-
cyclohexyl)-propane, octahydro-4,7-methano-1 H-indene dimethanol,
trimethylol propane, glycerol and/or pentaerythritol.
Optional monocarboxylic acids or monocarboxylic anhydrides c)
inciude acetic acid, propionic acid, n-octane carboxylic acid, 2-ethyl
hexanoic acid, stearic acid, benzoic acid, anhydrides of these acids and
mixtures of monocarboxylic acids and/or monocarboxylic anhydrides.
Olefinically ùnsaturated monocarboxylic acids (such as acrylic acid or
methacrylic acid) and unsaturated faUy acids or mixtures thereof (such as
soybean fatty acid or dehydrated castor oil fatty acid) may also be used
Mo3981
. ~ . . -. ~
L 9 2 rj1
-6 -
as, or as part of, component c) in the process according to the invention.
Hydroxy-functional carboxylic acids (such as hydrogenated castor oll fatty
acid, hydroxybenzoic acid and/or lactones, in particular e-caprolactone)
may also be used.
Optional alcohol component c) is selected from monohydric
alcohols such as methanol, ethanol, the isomeric propanols, butanols and
hexanols, cyclohexanol, benzyl alcohol, fatty alcohols and mixtures of
these alcohols.
The unsaturated polyesters are produced from the starting
materials mentioned by way of example by known methods as described,
for example, in "Ullmanns Encyclopadie der technischen Chemie", Verlag
Chemie, Weinheim, 4th Edition (1980), Vol. 19, pages 61 et seq.; by
H. Wagner and H.F. Sarx in "Lackkunstharze", Carl Hanser Verlag,
Munchen (1971), pages 85 et seq.; by G. Gerber and H. Gruber in
"Houben-Weyl", Methoden der organischen Chemie, Vol. E 20, Part 2,
pages 1405 et seq.; or by R. Dhein, D. Reuter and G. Ruf, ditto, pages
1429 et seq. The esterification is optionally carried out in the presence
of a catalytic quantity of a typical transesterification catalyst, e.g., acids,
bases or transition metal compounds, such as titanium tetrabutylate, at -
20 approx. 80 to 260C, preferably 100 to 230C. The esterification reaction
is continued until the required hydroxyl and acid values are reached.
The type and quantities of components a) to d) used are selected so that
the polyesters have the characteristics described above.
The equivalent ratio of carboxyl groups to hydroxyl groups is
generally 1:1.5 to 1:1, preferably 1:1.3 to 1:1. Anhydride groups
correspond to 2 carboxyl groups and are included as such in the
calculation.
The production of the unsaturated polyester resins may also be
Mo3981
11927
carried out by transesterifying esters based on polycarboxylic acids and
monohydric, readily volatile alcohols in combination with polyhydroxyl
compounds example or by using esters based on monohydric, readily
volatile carboxylic acids and polyhydroxyl compounds in combination with
5 polycarboxylic acids with elimination of the readily volatile alcohol or the
readily volatile acid. However, this method of producing the polyester
resins is less preferred.
In the process according to the invention, the olefinically
unsaturated polyester resins are reacted with ammonia or primary
10 amines corresponding to the formula:
R-NH2
wherein
R represents an aliphatic, cycloaliphatic or araliphatic radical which
may contain ether groups andlor hydroxyl groups, preferably an
aliphatic or cycloaliphatic hydrocarbon radical having up to 15
carbon atoms and optionally at least one alcoholic hydroxyl group.
Primary monoamines corresponding to the above formula wherein -
the primary amino group is attached to a secondary or tertiary carbon
atom, are particularly preferred reactants for the unsaturated polyester
20 resins.
Suitable amines corresponding to the above formula include
methyl amine, ethyl amine, 1-aminopropane, 2-aminopropane, 1-
aminobutane, 2-aminobutane, 1-amino-2-methyl propane, 2-amino-2-
methyl propane, 2-amino-2-methyl butane, 1-aminohexane, 1-amino-2-
25 ethyl hexane, 1-aminodecane, 1-aminododecane, 1-aminotetradecane, 1-
aminohexadecane, 1-aminooctadecane, allyl amine, cyclohexyl amine, 2-,
3- or 4-methyt cyclohexyl amine, aminomethyl cyclohexane, 3,3,5- .
trimethyl cyclohexyl amine, 1-aminomethyl-3- or 4-methyl-3-cyclohexene,
Mo3981
-
- ,
9 ~ 7
-8 -
benzyl amine, cyclopentyl amine, cyclooctyl amine, cyclopropyl amine,
cycloheptyl amine, cyclobutyl amine, cyclododecyl amine, 1-aminoindane,
2-aminoethanol, 2-methoxyethyl amine, 3-amino-1-propanol, 3-methoxy-
1-propyl amine, 3-ethoxy-1-propyl amine, 3-((2-ethylhexyl)oxy)-1-propyl
5 amine, 1-amino-2-propanol, 2-amino-1-butanol, 2-amino-2-methyl
propanol, 2-amino-2-methyl-propane-1,3-diol and 2-amino-2-hydroxy-
methyl propane-1,3-diol.
The addition of ammonia or primary amines to the unsaturated
polyester resins results in the formation of structural units corresponding
10 to the formula
. .: .
O O
--O--C--CH2--CH--C--O--
R'
15 wherein R' represents -NH2 or -NHR.
The type and quantities of the reactants reacted with one another
are selected so that amino-functional and optionally hydroxy-functional
polyester resins have the characteristics mentioned above. When
ammonia or amines which are gaseous at room temperature are used, -
20 excess quantities of the base are often added followed by the
subsequent removal of the unreacted excess under vacuum and/or by
the introduction of inert gas. When amines which are liquid at room
temperature are used, the equivalent ratio of primary amino groups to
structural units corresponding to the formula
O O '~
Il .
--0--C CH=CH C 0--
~.
Mo3981
9 2 7
can vary within wide limits, for example, from 0.05:1 to 1:1, preferably
0.1:1 to 1:1 and more preferably 0.1:1 to 0.6:1.
The reactlon generally takes place at temperatures of 0 to 120C,
preferably 20 to 100C. The reaction may be carried out in the presence
5 or absence of suitable solvents depending upon the viscosity of the
unsaturated polyester. Suitable solvents include toluene; xylene; higher
alkylbenzenes; esters such as ethyl acetate, n-butyl acetate, methyl
glycol acetate, ethyl glycol acetate and methoxybutyl acetate; ketones
such as methyl ethyl ketone and methyl isobutyl ketone; and mixtures of
10 these solvents.
As already mentioned, structural units corresponding to the
formula:
il R ~:
15--O--C CH2 CH--C O--
R'
wherein R' is defined as above,
are formed in the reaction according to the invention. The reactivity of
20 the amino group R' is greatly reduced by the electron-attracting effect
when compared with corresponding, electron-unhindered amino groups.
One possibility of variation regarding the reactivity of the products
according to the invention is to vary the ratio of incorporated hydroxyl
groups to incorporated amino groups by suitable choice of the starting
25 materials used in the process according to the invention and the
quantities in which they are used.
Depending upon their molecular weight, the products obtained by
the process according to the invention are generally low-viscosity to high-
Mo3981
~ ~ ~ 1927
-10-
viscosity, substantially colorless, clear resins which form clear solutions in
the previously mentioned lacquer solvents.
The products obtained in accordance with the invention may be
used in admixture with various quantities of other isocyanate-reactive
compounds, preferably known polyester or polyacrylate polyols containina
0,5 to 10, preferably 1 to 5 % by weight of hydroxyl groups. This provides another possibility
for controlling the reactivity of the component containing isocyanate-
reactive groups. In general, the isocyanate-reactive component used in
the application according to the invention contains up to 20 hydroxyl
groups for every primary or secondary amino group. The ratio of (i)
primary and/or secondary amino groups to (ii) hydroxyl groups in the
binder component containing isocyanate-reactive groups is preferably
10:1 to 1:10. The percentage of products according to the invention in
these mixtures is preferably 10 to 100% by weight. In a particularly
preferred embodiment, the products according to the invention are used
as sole isocyanate-reactive lacquer component. -
Reactants for the "polyol component" in accordance with the
invention are the known "lacquer polyisocyanates," i.e., the known ~ -~
urethane-modified, uretdione-modified or, in particular, biuret-modified or
isocyanurate-modified diisocyanates. Examples of these diisocyanates
include 1,6-diisocyanatohexane, 1-isocyanato-3,3,5-trimethyl-5-iso-
cyanatomethyl cyclohexane (isophorone diisocyanate~, 4,4-diiso-
cyanatodicyclohexyl methane, 2,4- and 2,6-diisocyanatotoluene.
"Lacquerpolyisocyanates" containing aliphatically and/orcyclo-
aliphatically bound isocyanate groups are particularly preferred. -
. . .
Urethane-modified lacquer polyisocyanates are preferably reaction
products of 2,4- and optionally 2,6-diisocyanatotoluene with less than
equivalent quantities of trimethylol propane or mixtures thereof with
Mo3981
~''''" ~
--` 211~'~27
-11-
simple diols such as the isomeric propane or butane diols The
production of these urethane-modified lacquer polyisocyanates in
substantially monomer-free form is described, for example, in DE-PS
1,090, 1 96.
Uretdione-modified lacquer polyisocyanates are preferably
prepared from 1,6-diisocyanatohexane as described, for example, in
EP-A-0,377, 1 77.
Biuret-modified lacquer polyisocyanates, which are preferred for
the use according to the invention, are preferably those prepared from
1,6-diisocyanatohexane as described, for example, in EP-B1 0,003,505,
DE-PS 1,101,394, US-PS 3,358,010 and US-PS 3,903,127.
Isocyanurate-modified polyisocyanates, which are also preferred
according to the invention, include in particular the isocyanate-functional
trimers or mixed trimers of the previously disclosed diisocyanates.
Examples include the isocyanate group-containing polyisocyanates
prepared from diisocyanatotoluene according to GB-PS 1,060,430,
GB-PS 1,506,373 or GB-PS 1,485,564; the mixed trimers prepared from
the diisocyanatotoluenes and 1,6-diisocyanatohexane in accordance with,
for example, DE-PS 1,644,809 or DE-OS 3,144,672; and, in particular,
the aliphatic or aliphatic-cycloaliphatic trimers or mixed trimers prepared
from 1,6-diisocyanatohexane andlor isophorone diisocyanate in
accordance with, for example, US-PS 4,324,879, US-PS 4,288,586,
DE-OS 3,100,262, DE-OS 3,100,263, DE-OS 3,033,860 or DE-OS
3, 1 44,672.
The lacquer polyisocyanates employed in the use according to the
invention preferably have an isocyanate content of 5 to 25% by weight
and preferably have a residual content of the monomeric diisocyanates
used for their production of less than 2% by weight. Mixtures of the
Mo3981
. 1 .. . ~ ~ .. . . . -
. ~ . . . - . ~ .
' ~ ` '' ' , ;, 1 ., ~ ` _ ,
, . ,, . ~ . . . .
~ ............... . . .
21~ ~927
-12-
previously mentioned lacquer polyisocyanates may also be used.
The two-component polyurethane coating compositions according
to the invention are formulated to have an equivalent ratio of isocyanate
groups to isocyanate-reactive groups of 5:1 to 1:2, preferably 1.5:1 to
1:1.2.
The two-component binders obtained by mixing the binder
components have only a limited pot life of about 0.5 to 8 hours. They
may be used for the production of clear or pigmented coating
compositions which may contain known auxiliaries and additives. The
auxiliaries and additives may be added either to the mixture or to the
individual components before they are mixed.
Suitable auxiliaries and additives include the previously mentioned
solvents; plasticizers such as tricresyl phosphate, phthalic acid diesters -
and chloroparaffins; pigments and fillers such as titanium dioxide, barium
sulfate, chalk and carbon black; catalysts such as N,N-dimethyl ~ --
benzylamine, N-methyl morpholine, zinc octoate, tin octoate and dibutyl
tin dilaurate; flow control agents; thickeners; stabilizers such as
substituted phenols; organofunctional silanes as coupling agents; and
light stabilizers. ;-~ -
The light stabilizers include the sterically hindered amines
described, for example, in DE-OS 2,417,353 (= US-PS 4,123,418 and
US-PS 4,110,304) and DE-OS 2,456,864 (= US-PS 3,993,655 and
US-PS 4,221,701). Partlcularly preferred compounds include bis- -
(1,2,2,6,6-pentamethyl-4-piperidyl)-sebacate, bis-(2,2,6,6-tetramethyl-4- . -
piperidyl)-sebacate, n-butyl-(3,5-ditert.butyl-4-hydroxybenzyl)-malonic acid
and bis-(1,2,2,6,6-pentamethyl-4-piperidyl)-ester.
The moisture adhering to the fillers and pigments may be removed
by preliminary drying or by the use of water-absorbing materials such as
: ,.
Mo3981 ~ ~
.. .... . . . ,, . -- , -- --
~;t ~ 2 7
-~3-
molecular sieve zeolite.
The resulting coatings may be dried at room temperature. Drying
does not require any increase in temperature to achieve optimum
properties. However, elevated temperatures may be applied to
5 accelerate the drying reaction. Drying temperatures used for typical
stoving conditions are possible, but less preferred. This is of consider-
able practical significance because, even at the relatively high
temperatures which may occur, for example, in the event of malfunctions
of lacquering plants, the coatings do not undergo thermal degradation.
Two-component polyurethane coating compositions containing the
products according to the invention as their principal binder component
are suitable for the production of coating compositions for any substrates
such as metals, plastics, wood or glass.
Because they are equally suitable for plastics and metals, the
15 coating compositions according to the invention are also particularly
suitable for coating substrates such as the exterior parts of automobiles
produced from modern plasticlmetal composites. The coating
compositions according to the invention are particulariy suitable for "on-
line" coating of exterior auto parts because the coatings cure at low
20 temperatures so that the plastics are not exposed to high temperatures.
Further, the resulting coatings show excellent weather resistance and
elasticity so that decorative lacquer finishes remain unchanged for long
periods and safely withstand impact stresses. The excellent chip
resistance of automotive coatings produced in accordance with the
25 invention is also particularly emphasized in this regard. The coatings
obtained with the two-component coating compositions according to the
invention optimally satisfy basically conflicting requirements, i.e. excellent
elasticity at low temperatures coupled with high resistance to solvents
Mo3981
2 ~
-14-
and tar stains, high gloss retention and resistance to yellowing on
exposure to light of short wave length, for example, short-wave UV light.
The coating compositions according to the invention may be
applied to the substrates to be coated by any known methods, for
example, by spread coating, spray coating, roll coating or dip coating.
The lacquers according to the invention are suitable for the production of
base coats, intermediate coats and top coats.
In the following examples, all parts and percentages are by weight,
unless otherwise indicated.
EXAMPLES .
1. General procedure for the production of the unsaturated polyester
precursors:
The monohydric and polyhydric alcohols and the unsaturated
dicarboxylic acid(s)/anhydride(s) were weighed into a reactor equipped
with a stirrer, heating system, automatic temperature control, column and : .
receiver. The mixture was heated to 100-150C while a stream of
nitrogen was passed through the inhomogeneous mixture of starting
materials. After the remaining dicarboxylic acids had been added, the ~ :
mixture of starting materials was heated with stirring to 200C over a
period of 4 to 8 hours while nitrogen was passed through the mixture.
The temperature measured at the head of the column was kept at a ..
maximum of 105C. The melt became homogeneous and clear. When
the head temperature fell below 90C, the column was removed and the
mixture was condensed with an increased throughput of nitrogen to an
acid value of ~ 3 mg KOH/g. - .
Colorless resins were obtained and were dissolved in methoxy- ~
propyl acetate, butyl acetate or mixtures thereof. ;.
The composition and properties of the individual polyesters are ; ~ .
Mo3981
-15~
given in Examples 1 and 2. The abbreviation "mol" applies to the molar
ratio and not to the actual number of "moles," as can be seen from the
quantities by weight in "g."
Exam~le 1
PolyesterA Quantity
weighed in
1.0 Mol hexane-1,6-diol 526 9
1.0 Mol trimethylol propane 596 g
1.5 Mol cyclohexane dimethanol 962 g
1.5 Mol neopentyl glycol 696 g
2.2 Mol adipic acid 1431 g
1.8 Mol maleic anhydride 786 g
Hydroxyl value: 145 mg KOHtg
Acid value: 0.7 mg KOH/g
Molecular weight: 1700
Example 2
Polyester B Quantity
weighed in
4.00 Mol hexane-1,6-diol 1949 g
1.00 Mol trimethylol propane 553 g
0.52 Mol adipic acid 314 g
0.52 Mol maleic anhydride 211 g
2.48 Mol Isophthalic acid 1701 g
0.48 Mol phthalic anhydride 293 9
Hydroxyl value: 140 mg KOH/g
Acid value: 1.2 rng KOH/g
Molecular weight: 1800
Mo3981
~ (3 2 7
-16-
2. General procedure for the reaction of unsaturated polyesters with
primary amines
Polyester precursors A and B from Examples 1 and 2 were
optionally dissolved in a suitable solvent and introduced into a 2-liter four-
5 necked flask equipped with a stirrer, thermometer, reflux condenser anddropping funnel and heated to 60C. The corresponding primary amine
was then added in one portion. The mixture was then stirred for 2 hours
at 60C, heated to 80C and stirred until no more primary amino groups
could be detected by titrimetry or until the solids content corresponded to
10 the theoretical value of the amine addition. The product was then cooled
and packed in containers.
3. General procedure for the reaction of unsaturated polyesters with
ammonia -
Polyester precursors A and B from Examples 1 and 2 were
15 optionally dissolved in a suitable solvent and introduced into a 2 liter four-
necked flask equipped with a stirrer, thermometer, reflux condenser and
inlet pipe. Ammonia from a steel boffle was then passed through the -
flask for about 4 hours at room temperature. The reaction mixture
heated up to about 30C. The reaction mixture was then stirred for about
20 4 hours at room temperature, after which unreacted ammonia was driven
out with nitrogen at 50C. The product was then cooled and packed in
containers.
~, ,.
' ~,
Mo3981
,::
: ~ ~; '' .' :, ~
~ 192 7
Y o a, O Oo O ~ O
N 't U'~
o ~ O U'~ .
U~ C~l CO
o) oU~ O
c~ o
~ O O 0 0 ~o
a~ ~ ,~
~D ~ O ~ O
.c o ~ a~ O ~ O
._ CO U~ ~
~r o ~ ~ o
8 O o ~ C5~ o
E W i~ 8
Mo3981
- ~111927
-18-
ExamPle 12 (Use)
This example describes the production of ready-to-use coating
compositions prepared from the aminopolyesters of Examples 3 to 10 as well as from the
polyesters of examples 1 and 2 ~comparison)~ their application to substrates and the testing
of the resulting coatings.
To evaluate the properties of the coating compositions, white
10 compositions were produced by blending the polyesters of Examples 1
to 10 with various additives and white pigments and grinding on a Red Devil
shaker. ~ - -
A lacquer polyisocyanate was then added to provide an NCO/NH+OH
equivalent ratio of about 1.3:1. -
The "lacquer polyisocyanate" used was an isocyanurate group-
containing polyisocyanate prepared from 1,6-diisocyanatohexane (Desmodur
N 3390, a product of Bayer AG) which is present at 90% solids in a 1:1 ratio
by volume of butyl acetate and Solvent Naphtha 100 solvent (NCO content
of the solution: 19.4% by weight).
The following percentages of additives were used, based on solids - -
(sum of the solid components of polyester and polyisocyanate):
, "~
Mo3981
-19-
Table 2
o/o
Additives Solid on solid
Zinc octoate t10% in 1-methoxypropyl-
2-acetate) 0.2
Silicone oil as flow control agent
(Baysilon lacquer additive OL 17, a
product of Bayer AG; 10% in 1-methoxy-
propyl-2-acetate) 0.1
Tinuvin 292 (a light stabilizer pro-
duced by Ciba-Geigy, Basel; 10% in
xylene) 1.0
Tinuvin 900 (a light stabilizer pro-
duced by Ciba-Geigy, Basel; 10% in
xylene) 1.0
Titanium dioxide (rutile type; Kronos
2160, a product of Kronos-Titan,
Leverkusen) 60.0
Antisedimenting agent (Bentone 38, a
product of Kronos-Titan, Leverkusen;
10% suspension in a 17:1 blend of Solvesso
100 solvent and Antiterra U 17:1 additive) 1.0
The solvent used was a mixture of ethyl acetate, 1-methoxypropyl-2-
acetate and methyl ethyl ketone (1:1:1). The coating composition was
diluted to a content of:
33% binder
20% pigment
approx. 1% additive
approx. 46% solvent
The flow time (DIN 53211; 4 mm orifice) was approx. 18 seconds. The
coating compositions were ready for spraying.
Mo3981
9 2 7
-20-
The lacquers were applied to glass plates (wet film thickness approx,
100 ,um), dried for 45 minutes at 80C and stored for 14 days at room
temperature. The dry film thickness was approx. 50 ,um.
Konig hardness (DIN 53157), Gardner gloss at 60 (DIN 67530),
5 dissolvability by various solvents and resistance to tar were then determined.The resistance of the coatings to tar stains was a critical aspect of the
invention.
To test their flexibility at low temperatures, the coating
compositions were sprayed onto primed 3 mm thick plastic plates of
10 Bayflex 91 (a product of Bayer AG, Leverkusen), dried for 45 minutes at
80C and stored for 14 days at room temperature. The dry film thickness
was approximately 35 ,um. 2 cm wide and 15 cm long strips prepared
therefrom were stored for approx. 30 minutes at various temperatures
(room temperature: 5C, 0C, -5C, ..., -40C) in a low-temperature
chamber and then bent around a 1 inch mandrel at the particular
temperature prevailing in the chamber. The temperature at which the
coating broke was the criterion for low-temperature flexibility. The
lacquers produced from the polyesters polyols of Examples 1 to 10
satisfied stringent elasticity requirements, even at low temperatures.
The test results of the coatings based on the aminopolyesters ~ -
according to the invention of Examples 3 to 10 and Comparison
Examples 1 and 2 are set out in Table 3.
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0 ~ `- o o ~ ~y
E ' 0 a~ ---- --
o ~ a~ ~ O o _ O O
CL
E r` U~ 0o o o _ o o o o o ~,
w a~ 0 0 0 _ O O O O O
_ u) a~ ~o --
C _ g
.C~ U~ ~ _ o ~ o o o o o U,~ o
~~ ~ _ _ _ o o o o o ~
o
o ~ u~ _ _ _ o o -- 91 ~ ~ 2 ~ :
E _o co _ _ _ o O -- ~ ~ c~
o e O ~
E o o ~ O
S ~ E el N 2 ~ e
E ~ E ¦ Q E ~ 8 E E O ' J ~ ~ ~ ~ o
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5 Discussion of the results:
Highly flexible coatings were obtained with coatings based on the
polyesters of Examples 1 to 10, the coatings of Examples 1, 3 and
4 providing the best results in regard to elasticity. The results of the tar
resistance tests reflect in particular the excellent resistance to tar of the
10 coatings of Examples 3 to 10 according to the invention in contrast to
comparison coatings 1 and 2.
ExamPle 13 (Use)
The aminopolyester (K) of Example 11 was used to formulate
clear coatings with the lacquer polyisocyanate of Example 12 and applied
15 to glass plates (dry film thickness approx. 60 ,um). The crosslinking ratio
and the solids content are set out in Table 4. Solvent resistance was
tested by the cotton wool pad method under the drying conditions shown
in Table 4. Hardness was determined by the pencil method. -~
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Table 4:
Clear coating compositions based on the aminopolyester of Example 11
according to the invention
Results of the solvent resistance and pencil hardness tests
Example 13
.. . .
Aminopolyester of Ex. 11
NCO/NH+OH ratio 1.2
Solvent BuAc
Solids content (%) 70
Drying 40'/80C
+ 1d RT :
Dissolvability" by
xylene o
Exposure time: MPA 0
1 minute acetone
EtOH/H2O 1:1 0
Pencil hardness 3H
" 0 best value, 5 poorest value
Although the invention has been described in detail in the
foregoing for the purpose of illustration, it is to be understood that such
detail is solely for that purpose and that variations can be made therein
by those skilled in the art without departing from the spirit and scope of ~ -~
25 the invention except as it may be limited by the claims.
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