Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
~`\
9617
~ ~ S~ ~7 3
The invention relates to aqueous phenolic resole
dispersions containing gum ghatti and a thickening agent.
In U.S. Patent No. 3,823,103, there is disclosed
aqueous phenolic resole dispersions that are produced in
the presence of gum arabic and at least one other gum.
These dispersions are characteriz~ed by excellent stability
and the ability to be infinitely diluted with water. In a
preferred aspect, they can have particles whose average
diameters are between about 5 to 20 microns, with substan-
tially all the resin particles having diameters less than
40 microns. -
In the text "Industrial Gums - Polysaccharides
and Their Derivatives", edited by Whistler and BeMiller
~Academic~Press, New York and London - 1973), on page 268
it is stated that gum ghatti is a better emulsifier than
gum arabic. On page 352 of the same text, it is stated
that Psyllium seed gum is recommended as a replacement for
,
gum arabic as an emulsifier, and on page 357, flax seed
gum is similarly recommended. Carboxy methyl cellulose,
which in many ways can be considered to be a synthetic
gum, is often recommended as a replacement for gum arabic
in emulsions.
~ The inventors herein have attempted to produce
aqueous résole dispersions by procedures analogous to the
process of this invention, and using, in turn, Psyllium
seed gum, flax seed gum, and carboxy methyl cellulose as
the interfacial agent. In each case, the results were
unsatisfactory. No phase înversion was obtained; there-
fore, no resin-in-water dispersion was produced.
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3L059G73
Wha~ the foregoing discussion demonstrates is
that the usefulness and effectiveness of a gum in the
produc~ion of aqueous resole dispersions cannot be pre-
dicted from its known performance in the end-use appli-
cations in which gums have heretofore been employed.
The invention provides an aqueous dispersion
containing dispersed particles of a phenolic resole, gum
ghatti, and a thickening agent. The invention also pro~
vides a process for producing such dispersions which com-
prises reacting a phenol with an aldehyde in the presenceof a basic ca~alyst, said reaction being carried out for
a period of time and at a temperature sufficient to pro-
duce à substantially water-insoluble phenolic resole, and
dispersing said phenolic resole in an aqueous medium in
the pr~sence of gum ghatti and a thickening agent.
The aldehydes employed to produce the phenolic
resole can be formaldehyde or a material that provides the
reaction mixture with formaldehyde or its equivalent such
as para-formaldehyde or hexamethylenetetramine, acetalde-
hyde, furfural, acrolein, or other aldehyde. Formaldehydeis preferred, especially as the aqueous solution known as
"formalin".
- The phenols that can be employed to produce the
resoles employed in the invention include unsubstituted
phenol (i.e., monohydroxybenzene), and various substituted
monohydric and polyhydric phenols. Illustrative examples
include o-, m- and p-cresol, ethylphenol, propylphenol,
para-tert.-butylphenol and other ~utylphenols, amylph~nol,
octylphenol, cyclohexylphenol, nonylphenol, dodecylphenol,
and-other alkylphenols; para-phenylphenol; styrenated
3.
~5~673 9617
phenol; halogenated phenols such as chloro- and bromophenols;
hydroquinone; and bisphenols such as 2,2~bis(4-hydroxy-
phenyl)propane (bisphenol-A) and bis(4-hydroxyphsnyl)
methane.
Monohydric phenols employed will normally be di-
or trifunctional. That is, 2 or 3 of the positions ortho
and para to the phenolic hydroxyl will normally be unsub
stituted. Bisphenols are usually tetrafunctional, although
up to 2 of the reactive positions ortho to the phenolic
hydroxyl can be substituted.
Ordinarily, from about 0.5 to about 4 moles, and
preferably from about 1 to about 3 moles, of aldehyde per
mole of phenol will be employed. As is known in the art,
more aldehyde is employed when the phenol is a bisphenol -
than when a monohydric phenol is used.
In producing a phenolic resoLe, an alkaline
cataiyst is employed. Specific illustrative catalysts
include alkali metal and alkaline earth metal hydroxides, ~ ~-
oxides, or carbonates,such as sodium hydro~ide, potassium
hydroxide, barium hydroxide, calcium oxide, sodium
carbonate, and the like; ammoniacal compounds such as
ammonia, hexamethylenetetramine, and quaternary ammonium
hydroxides; and amines such as ethylenediamine, trimethyl-
amine, dimethylamine, and N,N-dimethyl ethanolamine.
The catalyst is employed in catalytically sig-
nificant proportions, such as, from about 0.007 to about
0.4, and preferably from about O.~Ol to about O.l equiva-
lents of catalyst per mole of p~enol.
:,
4.
~596~3 9617
The aqueous dispersions of the invention are pro-
duced by a process which comprises reacting a phçnol with
an aldehyde in the presence of an alkaline catalyst to pro-
duce a substantially water-insoluble phenolic resole, and
dispersing said resole in an aqueous medium in the presence
of gum ghatti and a thickening agent.
A convenient way to carry out the process is the
following:
Charge the phenol, aldehyde, and catalyst to a
reaction vessel having conventional agitation, heat transfer,
reflux, and control means. It is convenient to include an
inert diluent to act as a reac~ion medium. Water is pre-
ferred, and will normally be added with the aldehyde, since
aqueous formaldehyde is the aldehyde used in most cases.
The condensation reaction between the phenol and aldehyde
is usually initiated by applying external heat to the
reaction mixture until the condensation reaction starts.
Thereafter, the exothermic nature of the reaction keeps it
going at the beginning of the reaction. Temperature control
is normally achieved by refluxing at a controlled pressure,
with external heating or cooling being employed as needed.
The condensation reaction is continued until at least a low
viscosity resole is produced. The viscosity should be low
enough so that, with the shear available in the reaction
- vessel, the resole can be broken down into a small particle
size resin.
At this point, additional water can be added to
the reaction mixture, along with the gum ghatti and thick
ening agent. In order to enhance the stability o~ the
resole, it is sometimes d~sirable to neutralize the alkaline
9617
~ ~9 6~ 3
catalyst before further processing. The pH of the reaction
mixture s~ould normally be about 9 or less, preferably about
3 to about 7.5, and more preferably about 4.5 to a~out 6.5,
after the initial phenol/aldehyde condensation reaction is
completed, i.e., after neutralization, if required. The
particular pH selected depends, in part, upon the nature of
the phenol and the end-use application intended for the dis- :
persion.
An important feature of the invention is that the
10 resole is dispersed in water, in the presence of gum ghatti ;-
and thickening agent, in situ. That is 3 the resole is dis-
persed in water before it is isolated from the reaction mix-
ture. If the resole is isolated from the reaction mixture,
and then later re-dispersed in water, it will not be possible
to obtain nearly as fine a particle size, nor will the dis-
persion be as stable.
The gum ghatti and/or thickening agent can be in
t~e reaction mixture from the beginning of the phenol/
aldehyde condensation reaction. However, it is preferred to
carry out the condensation reaction until a low viscosity resin
is produced, and then add gum ghatti, thickening agent, and
more water if necessary. (At this point, the resin may still
be at least partially soluble in water. The resole may not
- become substantially water-insoluble until after neutralization
and/or bodying.) Enough water must be present in the
dispersion to enable a phase inversion to take place, i.e,,
to yield a resin-in-water dispersion (the water being the
continuous phase~. Typical maximum resole solids concen-
trations are within the range of from about 40 to about 50
weight per cent, determined by measuring the weight loss
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~ ~ 6.
.. .. ~ .. .
~05~673 9617
of a 1.5 gram sample after 3 hours in a 135C. oven.
When the phenol is unsubstituteaL phenol, the maximum per-
missible solids content tends to be near the lower end of :~
this range. When the phenol is bisphenol-A, the maximum
permissible solids content tends to be near the upper part
of the range, and when the phenol is an alkyl phenol, the
m~ximum permissible solids content tends to be near the
,
:.
'~ '
6A. .
~S96~3 9617
middle of the range. Of course, more water may be employed.
Howev~r, for various commercial reasons (such as the desire
to keep shipping costs low), it i~s usually preferred to
maintain the water content as low as possible.
As has been pointed out above, the best time to
add gum ghatti, thickening agent, and additional water (as
needed) to the reaction mixture, is not later than that
point in the reaction when a low viscosity resin is produced.
(The condensation reaction is carried out at elevated temper- -~
atures, e.g., 75 to 105C., and at these temperatures the
resole will be liquid.) One or two experiments will probably
be required to determine the best point at which to add the
gum ghatti, thickening agent, and water, for particular
resoles. However, phenolic resin chemists, who have been
making resoles commercially for 40* years~ are fully capable
of determining that point after having read this disclosure.
The dispersion of the resole in water will be
effected by applying shear to the reaction mixture contain-
ing substantially water-insoluble resole, water, gum ghatti,
and thickening agen~. Agi~ation of the reaction mixture is
the most convenient way to provide the requisite shear.
The resole must be substantially water-insoluble.
While it varies somewhat, depend-.ing on the exact nature of
the resole, normally to be water-insoluble, the resole must
have a weight average molecular weight of at least about 400.
The resoles of the invention ca~ have weight average molecular
weights of up to about 3000 or more. Weight average molecul~r
weight can be determined by known procedures, e.g., see Moore,
"J. Poly. Sci., Part A," 2, 835, 1964.
7.
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1~59~;73
In order to attain the degree of advancement of
t~e resole that is desired for t~e end-use application for
which it is intended, it is often desirable to subject the
resole to elevated temperature for a controlled period of
time after addition of gum ghatti, thickening agent, and
water> and, if it is done, after neutralization of the
catalyst. This treatment is often called "bodying" the
resin. It is ordinarily carried out at a temperature of
from about 80C. to 95C., for a period of about 5 minutes
up to 2 hours or more. When the resole is a th~rmosetting
material, the advancement can be followed by periodically
testing the resole for its 150C. gel time (e.g., every
15 to 20 minutes) until the desired degree of advancement
is attained. Phenolic resin chemists are well acquainted
with this concept, and know how much advancement is needed
for particular end-use applications.
Gum ghatti and a thickener are employed to produce
the dispersions of the invention. Gum ghatti is a naturally
occurring plant exudate obtained from the stems of Ano~issue
latifolia, a plant that is abundant in India and Sri Lanka
(Ceylon). It is a polysaccharide containing D-galactose,
mannose, glucuronic acid, and rhamnose units. The gum
ghatti is employed in an amoun~ sufficient to form and
stabilize a dispersion of resole particles in water. Effec-
tive amounts of gum ghatti will ordinarily be found within
the range of from about 0.5 to about 5, and preferably from ~;~
about 1 ~o about 3, parts by weight, per 100 parts by weight
of phenol charged to the reaction mixture.
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~S9673 9617
'''' ,
The thickening agent that is employed can be one
or more of the following materials: gums such as guar gum,
gum carregeenin, algin gum, locust bean gum; and water-
soluble polymers such as ethylene-maleic acid copolymer,
ionomers, poly(acrylamide), methyl vinyl ether-maleic
anhydride copolymer; and any other water-soluble polymeric
material that increase~ the viscosity of water and is com-
patible with the other components of the dispersion.
The thickening agent is employed in an amount
sufficient to increase the viscosity of the dispersion to at
least about 500 centipoises at 23C. As a general rule, an
effective amount of thickening agent will usually be found
within the range of from about 0.1 to about 1, and prefer-
ably from about 0.25 to about 0.8, parts by weight, per 100
parts by weight of phenol charged to the reaction mixture.
The individual phenolic resole particles contained
in the aqueous dispersions of the invention can be smaller - ~ 3
and more uniform in size than those of the phenolic disper-
sions produced using gum arabic as the interfacial agent.
For instance, dispersions produced in accordance with the
invention can have particles having virtually all of their
diameters below 5 microns, with their average diameters being
between about 1 and 3 microns. While the invention does
include dispersions whose particles are larger (for instance,
wherein the average particle diameters are below about 12
microns, with virtually all the particle diameters being
below about 25 microns), for many end use applications the
utility is enhanced when the particle siæe is smaller and
more uniform. Examples of such end use applications include
adhesive and coating applications wherein the phenolic dis-
9 .
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,.......... . . - :,~ . . .. .
~5~673 9617
persion is employed in conjunction with an addition polymer
latex such as an acrylic latex.
The smallest and most uniform particle size dis-
persions that we have made to date using gum arabic as the
interfacial agent, have particles whose diameters vary from
about 5 to about 10 microns.
The following Examples illustrate the practice of
the invention:
EXAMPLE 1
10 Into a five-liter, round bottom flask, equipped
with a reflux condenser, agitator, thermometer, and heating
mantle, there was charged the following:
Phenol 1200 grams
40 per cent Aqueous Formaldehyde 1668 grams
25 per cent Aqueous Sodium Hydroxide 100 grams
This mixture was heated, with agitation, to a temperature of
70C., whereupon the heating mantle was removed and the re-
action mixture allowed to rise in temperature to atmospheric
reflu~ through its exothermic heat o reaction. (The re-
20 action temperature at atmospheric reflux is about 102C.~ ;
The initial vigor of the reaction was moderat~d as necessary
to prevent excessive flooding of the condenser by cooling
with a cold water bath.
This mixture was allowed to reflux for about 30minutes. At the end of this reflux period, the following
were added in the order listed:
Water 720 grams
Gum Ghatti 24 grams
Guar Gum 6 grams
20 per cent Aqueous Sulfuric Acid 138 grams
After mixing for five minutes, the pH was found to be 5 2
10,
.
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~5~6~3
The contents of the flask were then heated to
80C., and held at about 80C. for forty minutes. At the
end of this forty minutes, the contents of the flask were
cooled to below 30C. and discharged into a suitable con-
tainer as a dispersion of phenolic resole in water having
the following properties:
Solids 41.2 percent
pH 5.5 ~;
Hot Plate Gel (150~C.) 110 seconds
Viscosity (Brookfield) 1050 centipoises
at 25C. ;
Particle Size 1-3 microns
(by microscope examination)
No significant settling of the resin particles ~
was apparent af~er 16 weeks at room temperature. The dis- ;
persion could be infinitely diluted with water.
The guar gum used in the above example is a
commercial product sold by Stein, Hall & Company, Inc.,
under the trade mark designation "Jaguar J2Sl."
The gum ghatti employed in this and other Examples
was "Grade 1", and was obtained either from Stein, Hall or
from Matheson, Coleman & Bell.
CONTROL 1
This experiment illustrates the effect of using
gum ghatti alone, without the thickening agent.
The apparatus and procedure of Example 1 were used
with the exception that no guar gum was added. The follow-
ing were charged to the five-liter flask: `
Phenol 1200 grams `~
40 percent Aqueous Formaldehyde 1668 grams
25 percent Aqueous Sodium Hydroxide 100 grams
11 .
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lOS9G73
; This mixture was heated to 71C., the heating mantle removed,
and the temperature allowed to rise by the exothermic heat of
reaction. The mixture was allowed to react for about 30
minutes at atmospheric reflux. At the end o~ the 30 minutes,
the following were added in the order listed:
Water 720 grams
Gum Ghatti ~4 grams
20 per cent Aqueous Sulfuric Acid 135 grams
The pH of the resulting mixture was adjusted to 5.6 by
addition of 10 grams of 25 per cent aqueous sodium hydroxide.
The contents of the flask were then heated to about
80C., held at that temperature for about 60 minutes, and
~ cooled to below 30C. The resulting dispersion of a phenolic
resole had particles ranging from about 2 to about 30 microns.
This was Ln marked contrast to the 1-3 microns sized particles
in the product of Example 1. Because of the larger particles
and the lower viscosity of the product of this experiment,
settling was rapid.
EXAMPLE 2
Prepara~ion of Phenolic Dispersion (Bisphenol-A Derived~
Using Ghatti Gum With Guar Gum
Into a 5-liter, round bottom flask, equipped with
a reflux condenser, agitator, thermometer, and heating mantle,
~here was charged 1200 grams of Bisphenol-A, 924 grams of
rl ' .
aqueous formaldehyde (40 per cent), and 14.4 grams of aqueous
sodi~m hydroxide (25 per cent). The mixture was heated to
about 90C. whereupon the heating mantle was removed and the
.
; mixture allowed to reach a stage of reflux at 95C., under
~acuum such that the pressure on the reaction mixture was
5-6 inches of mercury below atmospheric. The mixture was
then refluxed for 60 minutes at 95C. with additional heat
... .
12.
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~5967~ 9617
provided as necessary. At the end of the 60-minute period,
864 grams of water, 24 grams o-f ghatti gum, and 3.6 grams of
guar gum (Jaguar 507 - Stein,Hall & Company, Inc.) were added
to the contents of the flask with vigorous agita~ion. Then
10.8 grams of 42 per cent aqueous phosphoric acid were added
to the flask and the pH adjusted to 6.2. The contents of the
flask were then brought to a temperature of about 90C. and
maintained at this temperature for 90 minutes. At the end of
this time, ~he contents of the reaction flask were cooled to
a temperature below 50~C. and discharged as a resin-in-water
dispersion having a solids content of 48 per cent by weight
and a 150C. gel of 155 seconds. The dispersion viscosity
(Brookfield spindle #2 at 30 rpm) was 1050 cps. and the resin
~t particle size was substantially between 2 and 5 microns. This
material did not s~parate at all after standing for 13 weeks.
CONTROL 2
Preparation of Phenolic Dispersion (Bisphenol-A Derived)
Without Use of Thickening Agent
A phenoli~ dispersion was prepared substantial1y
as in the preceding Example 2, except that no guar gum was
added to the reaction mixture. The viscosity of this dis-
~ .
persion (Brookfield spindle #2 at 30 rpm) was 150 cps. and ~r
the resin particle size ranged from 2 to 25 microns with an
average size of about l0 microns. This material settled to
the extent of about 25 per cent after standing ~or 3 weeks.
EXAMPLE 3
Preparation of Phenolic Dispersion (Bisphenol-A Derived~
Locust Bean Gum Replacing Guar G~m
Into a 5-liter, round bottom flask, equipped with
a reflux condenser, agitator, thermometer, and heating mantle,
there was charged l000 grams of Bisphenol-A, 770 grams of
aqueous ~ormaldehyde (40 per cent~, and 12.2 grams of
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9617
~ 596~73
aqueous sodium hydroxide (25 per cent). The mixture was
heated to 90C. whereupon the heating mantle was removed ;
and the mixture allowed to reach a stage of reflux at
95C. under an absolute pressure of 5-6 inches of mercury
below atmospheric. The mixture was then refluxed for 60
minutes at 95C. with additional heat provided as necessary.
At the end of the 60-minute period, 770 grams of water, 20
grams of ghatti gum, and 6.5 grams of locust bean gum (175 --
mesh - from Stein,Hall) were added to the contents of the
flask with vigorous agitation. Then 8.0 grams of aqueous
phosphoric acid (42 per cent) were added to the flask and
the pH adjusted to 6.5. The contents of the flask were
then brought to a temperature of about 90C. and maintained
at this temperature for 120 minutes. At the end of this
time, the contents of the reaction flask were cooled to a
temperature below 50C. and discharged as a resin-in-water
dispersion having a solids content of 48 per cent by
weight and a 150C. hot plate gel time of 171 seconds.
The viscosity of the dispersion was 2000 cps. (Brookfield
spindle ~2 at 30 rpm), and the dispersed resin particle
size was substantially between 2 and 5 microns in diameter.
This material did not settle significantly after standing
for 8 weeks.
EX~MPLE 4
Preparation o~ Phenolic Dispersion (Bisphenol-A Derived)
With Sodium Alginate Replacing Guar Gum
The same formulation and procedure as Example 3 was
followed, except that 4.5 grams of sodium alginate ("Alginic
acid, Sodium Salt - Practicall' from Matheson, Coleman & Bell)
replaced 6.5 grams of locust bean gum. The dispersion's
viscosity (Brookfield spindle ~2 at 30 rpm) was 770 cps. and
14.
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1~59~73
the resin particle size was substantially between 2 and 5
microns in diameter. This material did not settle at all
after standing for 3 weeks. After 8 weeks, settling was
less than 5 per cent.
EXAMPLE 5
Preparation of Phenolic Dispersion (Bisphenol-A Derived)
"~MA-81" (Ethylene/Maleic Anhydride Copolymer from ~lonsanto)
Replacing Guar Gum
The same procedure and formulation as Example 3
were used', except 7.0 grams o-f EMA-81 replaced 6.5 grams of
locust bean gum and no phosphoric acid was used to neutralize
the reaction mixture. The dispersion's viscosity was 16,400
cps. and the resin particle size was substantially between
2 and 5 microns in diameter. This material did not settle
after standing for 7 weeks.
Probably, a lower'concentration of EMA-81 would be
desirable in some cases, in order to yield a dispersion ~'~
having a lower viscosity, which would be easier to handle.
EXAMPLE 6
Preparation of Phenolic Dispersion (Alkyl Phenol Derived)
Using Ghatti Gum and Guar Gum
Into a 5-liter, round bottom flask, equipped wi~h
a reflux condenser, agitator, thermometer and heating mantle,
there was charged 1200 grams of para-t-butylphenol, 1200 grams
of aqueous 40 per cent formalin, and 36 grams of aqueous sodium
hydroxide (25 per cent). The mixture was heated to 73C.,
whereupon the heating mantle was removed and the mixture
allowed to reach 80C., at which temperature it was kept for
2 hours. At the end of this period, it was heated to atmos-
30 pheric reflux and kept there for 60 minutes. At the end of "
this period, 780 grams of water, 24 grams of ghatti gum,
and 4.8 grams of guar gum were added to the contents of t'he
i~
.
,,; ;
9617
1~9S96~3
flask with vigorous agitation. Then 10.8 grams of aqueousphosphoric acid (42 per cent) were added and the pH adjusted
to 6.7. The contents of the flask were then brought to
95C. and maintained at this temperature for 2 hours. At
the end of ~his time, the contents of the flask were cooled
to a temperature below 50C. and discharged as a resin in-
water dispersion. The dispersion's viscosity (Brookfield
spindle #2 at 30 rpm) was 890 cps. and the resin particle
size was substantially between 5 and 18 microns. This
material did not separate after standing for 12 weeks.
In the experiment of Example 6, the phenollform-
aldehyde condensation reaction was carried out at a lower
temperature than the other Examples herein, for the following
reasons:
The condensation reaction between the t-butylphenol
and formaldehyde is relatively slow because of the low
solubility of t-butylphenol in water. The resole products
of this reaction which contain three or more phenol nuclei
contain hyperacidic phenolic hydroxyls, and therefore these
products tend to lower the pH of the reaction mixture more
than "conventionall' resoles. For these two reasons, more
alkali is required for catalysis. However, the higher con-
centration of alkali tends to increase ~he incidence of side
reactions, especially the Cannizzaro reaction. But, the
reacti.on rate of the desired condensation reaction is
reduced by a much lesser degree than that of the Canniæzaro
reaction by lowering the temperature. Therefore, a lower
reaction temperature is used, which, although it requires
a longer reaction time, serves to reduce the incidence of
side reactions.
16.
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1~59&i73
EXAMPLE 7 `
Preparation of Phenolic Dispersion (Phenol-Alkyl Phenol
Derived) Using Ghatti Gum and Guar Gum
Into a 5-liter, round bottom flask, equipped with
a reflux condenser, agitator, thermometer and heating mantle,
there was charged 600 grams of phenol, 600 grams of p-nonyl-
~ phenol, 933 grams of aqueous formaldehyde (40 percent), and
24 grams of aqueous sodium hydroxide (25 percent~. The mix- :
ture was heated to 85C. whereupon the heating mantle was
lowered and the mixture allowed to reach a stage of atmos-
pheric reflux through its exothermic heat of reaction. The
mixture was then re1uxed for 65 minutes. At the end of th~s ;~
period, 720 grams of water, 24 grams of gum ghatti, and 4.8 .
grams of guar gum were added to the contents of the flask.
Then there was added to the flask 16 grams of aqueous phos-
phoric acid (42 percent) and the pH of the mixture adjusted
to 6.65. The contents of the flask were then brought to
~5C. and maintained at this temperature for one hour. At
the end of this ,time, the contents of the flask were cooled
to a temperature below 50C. and discharged as a resin-in-
water dispersion. The viscosity (Brookfield spindle #2 at
30 rpm) of the dispersion was 2360 cps. and the resin `
particle size was substantially between 2 and 6 microns. .-
The dispersion did not separate after standing 12 weeks.
CONTROL 3 -;
This is an experiment illustrating the use of gum
ghatti and "Darvan #2" (trade mark designation of R. T.
Vanderbelt Company) in the preparation of a "Vinsol" modified
phenolic resole in dispersion form, as described in the
Hercules brochure on Vinsol Resin as Modifier of Phenolic
Resins J copyright 1955, page 23.
17.
- . . .;
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~59673 9617
Into a five-liter, round bottom flask equipped
with a reflux condenser, agitator, thermometer, and heating
mantle, there was charged the following:
Phenol 1005 grams
Vinsol 495 grams
40 per cent Formaldehyde884 grams
Water 67.5 grams
Paraformaldehyde 350 grams
This mixture was heated to atmospheric reflux with continuous
stirring, and held until the paraformaldehyde had dissolved.
The contents of the flask were then cooled to 26C. and the
following added:
Ammonium Hydroxide 29.6 per cent 318 grams
Gum Ghatti 27 grams
Darvan #2 4.5 grams
The resulting mixture was then heated to a temperature of ` -
75C., whereupon the heating mantle was removed, and the
temperature allowed to rise through the exothermic heat of
reaction. When the temperature reached 98C., additional
heating was used to bring the mixture to atmospheric reflux.
Reaction at atmospheric reflux was continued for a total of
three hours. The mixture was the~ cooled to below 40C.
The reswlting product was an aqueous dispersion
of a phenolic resin having a particle size range from about
2 microns up to about 160 micrvns. Upon standing for two
days at room temperature, the dispersed resin phase had
- settled, and could be redispersed only with vigorous stirring.
"Darvan #2" is supplied by the R. T. Vanderbilt
Company. It i8 the "sodium salt of polymerized substituted
benzoid alkyl sulfonic acids."
9617
~ ~ S~ ~ 3
CONTROL 4
This experiment differs from Control 3 in that the
"Vinsol" is omitted.
The apparatus and procedure o~ Control 3 were used.
The following were charged to the five-liter flask:
Phenol 1005 grams
40 per cent Formaldehyde 884 grams
Water 67.5 grams
Pàraformaldehyde 307.5 grams
The above mixture was heated at atmospheric reflux until the
paraformaldehyde had dissolved. After cooling to 34C., the
following were added:
Ammonium Hydroxide 29.6 per cent 318 grams
Gum Ghatti 27 grams -
Darvan #2 4.5 grams
The temperature of the mixture rose through the exothermic
heat of reaction. When atmospheric reflux began, the reaction
was moderated by cooling with a cold water bath as necessary
to control foaming and prevent flooding of the condenser.
After three hours a~ atmospheric reflux, the contents of the
flask were cooled to below 40C.
Microscope examination of the~phenolic dispersion
obtained show a wide range of particle sizes up to 160-200
microns in diameter with a large percentage of particles
being 50 microns or larger.
The dispersions of this invention are stable for
extended periods of time. For instance, in most cases, no
appreciable settling of the resole particles occurs upon
standing for 4 weeks, and in many cases, much longer, as the
foregoing Examples illustrate.
19 .
... . .
