Note: Descriptions are shown in the official language in which they were submitted.
12~6Z7~)
-1- 60SI-4Q9
~ATER BASED RESIN EMULSION5
BACKGROUND OF T~E INVENTION
This invention relates to water-based
emulsions of organopolysiloxane resins which are
useful in coating applications where aqueous emulsions
are preferable over traditional organic solvent based
systems. The present invention provides both water-
ba~ed silicone emulsions as well as methods for
producing such compositions.
Silicone resins are often selected for
applications requiring premium properties. These
organopolysiloxane resins are known to offer outstanding
endurance to environmental conditions æuch as weathering
and extreme heat and cold. Silicone resins have found
utility in a variety of applications such as pressure
sensitive adhesives and release coatings. Furthermore,
they have heen found to be particuarly useful in the
paint industry which is continually seeking coating
formulations which offer premium properties. Silicone
2a resin solutions have previously been used in the paint
coatings industry as vehicles and binders which are a
necessary paxt of quality paint formulations.
Heretofore silicone resins were ordinarily
supplied to formulators in solutions, that is to say,
the resin consisted of so many parts by weight of
silicone solids in some organic solvent such as xylene
or toluene. However, recently the use of such organic
solvents has ~een discouraged due to escalating costs
for organic materials and increased concern for
~2~6'~70
60SI-409
--2--
environmental considerations. Organic solvent based
silicone resins often required the use of costly and
cumbersome pollution abatement procedures and equip-
ment. Thus there has been a trend in recent years
for silicone resin systems which are water-based and
therefore not dependent upon organic solvents.
However, such silicone resins which have been
found to have particular utility in the art of paints
and other coatings have often been immiscible or
otherwise incompatible with aqueous coating systems.
The present inyention provides for the first time
silicone resins which can be readily dispersed into
water-based emulsion compositions thereby providing
the beneficial properties of silicone resins without
the cumbersome necessity of unduly large amounts of
organic solvents.
As noted above, silicone resins are intended as
high performance coating vehicles which can ~e used in
high temperature-resistant coatings and will generally
outperform conyentional organic resins in similar
applications. Those skilled in the art will recognize
that there are a number of silicone resins which can be
utilized in coating applications. Those silicone resins
proYided in U.S. Patents 4,Q28,339, issued ~une 7, 1977
25 and 4,a56,492, issued November 1, 1977, both issued to
Merrill, are examples of resins which can be made
part of the water-based emulsion compositions of the
present invention.
Previously known silicone resin emulsions have
3Q ~een succesfully utilized in coating glass fabric,
however, such compositions require the use of nonionic
emulsifiers, such as alkylphenoxy polyethoxyethanol.
In such a system there is generally required approximately
one part e~ulsifier for each nine parts of resin solids.
When this type of emulsion technology is attempted in
conjunction with the resin coating formulations
12~627(~
- 3 - 60SI 409
discussed herein, as required by paint formulators,
residual emulsifier is entrained in the coating and has
a significant deleterious effect on such coatings at
elevated temperatures. Also known are silicone resin
emulsions based on a combination of nonionic and
anionic emulsifiers and these can include "acid thickeners
based on a carboxyvinyl polymer of high molecular weight"
see, e.g., U.S. Patent 4,052,331, issued October 1, 1977
to Dumoulin, Col. 6, line 58. Also disclosed are composi-
tions containing small amounts of polyvinyl alcohol, of
rather high saponification number. Such compositions can
be formulated into sun-screens, for example, for
applications to human skin, but acid thickeners might not
be well tolerated. Use as coatings for unbleached kraft
paper is also disclosed.
The present invention, on the other hand, utilizes an
emulsion system based upon a combination of nonionic and/or
anionic surfactants and certain vinyl addition polymeric
emulsification agents having pendent hydroxyl groups or
pendent neutralized carboxyl groups or mixtures of such
groups. The total emulsifier requirement for the emulsions
of the present invention is generally in the range of
approximately 0.5 to 50.0 percent based upon the weight
of the silicone resin solids. Additionally, it seems that
the use of vinyl addition polymer emulsification agents
having pendent hydroxyl groups or pendent neutralized
carboxyl groups or mixtures of such groups as co-agents
enables the water-based compositions to coat out more
uniformly as compared to the above-described emulsions
utilizing nonionic emulsifiers, which tend to produce
"fish-eyes" in the film.
It is therefore a primary object of the present inven-
tion to provide water-based emulsions of organopolysiloxane
resins which are useful in coating compositions.
It is another object to provide an emulsifier system
comprising a combination of nonionic and/or anionic
- 4 - 60SI 409
surfactant and polymeric emulsification agent having
pendent hydroxyl groups or pendent neutralized carboxyl
groups or mixtures of such groups which are effective for
dispersing silicone resins in a water-based coating system.
It is another object to provide a process for
producing water-based silicon resin emulsions.
These and other objects will become apparent to those
skilled in the art upon consideration of the accompanying
description and claims.
SUMMARY OF THE INVENTION
The water-based silicone emulsions of the present
invention are comprised of (a) 100 parts by weight of at
least one organopolysiloxane resin composition consisting
approximately of zero to 50 percent by weight of mono-
functional units having the general formula R3SiOo 5~ zero
to 60 percent by weight difunctional units of the formula
R2SiO, zero to 100 percent by weight trifunctional units
having the general formula RSiOl 5, and zero to 60 percent
by weight tetrafunctional units having the general formula
SiO2. In the above formulae R represents a substituted or
unsubstituted monovalent hydrocarbon radical which will
ordinarily be selected from the group consisting of,
independently, methyl and phenyl radicals. The organo-
polysiloxane resins utilized in the present invention will
ordinarily have an R to Si ratio of, approximately, 1.0 to
1.99 R groups for each silicon atom. It is to be under-
stood that the present invention contemplates the use of
blends of different organopolysiloxane resins in the present
emulsions as well as the use of a single type resin for
each emulsion.
A more particular example of organopolysiloxane resins
which are useful in the emulsions of the present inventions
are those comprised of, approximately, 5 to 40 percent by
weight CH3SiO1 5 units, zero to 35 percent (CH3)2SiO units,
15 to 65 percent (C6H5)SiO1 5 units, and zero to 50 percent
(C6H5)2SiO units, wherein there is present, approximately,
1~6270
- 5 ~ 60SI 409
1.0 to 1.8 organic radicals for each silicon atom.
It is to be noted that -these organopolysiloxane
resins can be emulsified in water through the process
described in the present invention. However, it is common
in the art of silicone resins that such resins be provided
in solutions consisting of some specified weight percent
silicone resin solids based upon the weight of said
silicone solids and the solvent. For example, the
silicone resin may be provided as an approximately
20 to 90 percent by weight silicone resin solution
in an organic solvent as toluene or xylene. It is
to be noted that this organic solvent, if present,
is not a critical component of the present invention
nor does it ordinarily detract in any way from the
useful properties of these water-based silicone
emulsions. Indeed, often the presence of small amounts
of organic solvents in such emulsions impart otherwise
beneficial properties to such emulsions.
The water-based emulsions of the above-described
silicone resins are provided by utilizing a combination
of emulsifying agents. The amount of emulsifying agents
required to emulsify each 100 parts by weight resin
solids will vary widely depending upon process conditions
and the selection of the remaining constituent ingredients
of the emulsion. Those skilled in the art will be able
to produce a variety of water-based silicone resin
emulsions according to the method set forth herein,
and will be able to ad~ust the amount of emulsifying
agents according to individual desires. Without
intending to limit the scope of the present
invention in any way, it will ordinarily be the case
that, approximately, 0.25 to 50 parts by weight of
the combination of emulsifying agents will be necessary
to produce the water-based silicone resin emulsions
of the present invention. It has been discovered by
the present invention that a particular combination of
12~6Z70 60SI-409
--6--
emulsifying agents is effective for dispersing these
silicone resins and thereby providing water-based
emulsions. The combination of emulsifying agents is
comprised of 5 to 95 percent by weight of an
emulsification agent comprising a vinyl addition polymer
having pendent hydroxyl groups or pendent neutralized
carboxyl groups or mixtures of such groups in
combination with 95 to 5 percent by weight of a
nonionic or an anionic surfactant or emulsifying agent.
For example, 70 to 75 percent by weight vinyl addition
polymer emulsifier and 25 to 30 percent of nonionic
and/or anionic surfactant are known to provide
satisfactory emulsions in accordance with the present
disclosure. Particular examples of each of these types
of emulsifiers are given later in the specification.
~hen an effective amount of such combinations of
emulsifying agents are combined with the organopoly-
siloxane resins in the presence of water, a water-based
silicone resin emulsion can be provided through the
utilization of well known emulsification techniques such
as colloid milling. The amount of water present is not
critical and will ordinarily depend upon the application
to which the emulsion will be put. The amount of water
is merely dependent upon a desire to provide a
preselected silicone resins solidscontent by weight
in the resulting emulsion. As stated, although the
amount of water is not critical there will ordinarily
be approximately 50 to 300 parts by weight of this
water per lO0 parts of the organopolysiloxane resin.
The process of the present invention provides
the above described water based silicone resin emulsion
compositions by combining the specified constituent
ingredients and then applying well known emulsification
techniques.
~2~27()
- 7 - 60SI 409
DESCRIPTION OF THE INVENTIO
Sili.cone resins which may be used in the compositions of the
present invention may be prepared by a number of well known processes
such as, for example, by hydrolyzing an organohalosilane blend wherein
the eomposition of the resin can be varied by ehanging the proportions of
the eonstituent organohalosilanes to be hydrolyzed. An exernplary resin
might start with a blend of about 60 mole percent methyltrichlorosilane,
about 35 mole percent of phenyltriehlorosilane and about 5 mole percent
of dimethyldichlorosilane in the presence of water, aeetone and a water-
immiscible organic solvent. In general, this hydrolysis medium could
contain from about 1.7 parts to lO parts of water, 0.2 to 5 parts of
acetone and 0.3 to 5 parts of said water-immiscible organic solvent per
part by weight of the silane blend.
The organo groups in the organohalosilanes to be hydrolyzed
are broadly selected from monovalent hydrocarbon radicals and halogenated
monovalent hydrocarbon radicals, preferably not exceeding ten carbon
atoms. Accordingly, the organo groups can be selected from alkyl groups
of 1 to 10 carbon atoms such as methyl, ethyl, propyl, and alkenyl,
substituent groups of 2 to 10 carbon atoms such as vinyl, alkyl, mono-
nuelear aromatic radicals such as a phenyl, methylphenyl and so forth;
fluorinated alkyl radicals and more specifically fluorinated alkyl
radieals of 1 to lO earbon atoms such as trifluoropropyl. Most
preferably, the organo groups in the above organohalosilanes are selected
from methyl, ethyl, phenyl, vinyl and trifluoropropyl.
The various components of the hydrolysis mixture can be added
concomitantly or separately in any desired order. Generally, the organo-
halosilanes are added to the mixture of water, acetone and organie solvent.
Preferably, when this method is used a proportion of Erorn 2 to 6 parts of
water, about 0.3 to 2 parts of aeetone, and about 0.6 to about 2 parts
of organie solvent, per part of the total weight of organohalosilane blend,
is employed. It is preferred that the organohalosilanes are added to the
hydrolysis medium, rather than vice versa, as this limits the concentration
of hydroehloric acid which is formed during the hydrolysis reaction. A
strong hydrochloric acid solution is undesirable in this example as the
hydroehloric acid causes acid polymerization of the acetone forming poly-
merization products whieh add undesirable eolor to the produet and have a
deleterious effect on the physical properties of the product.
`` 12~6270
60SI-409
--8--
A preferred method to prepare organopoly-
siloxane resins which may he used in this invention
is the dual feed process. The dual feed process
comprises feeding the ~lend of organohalosilanes
and from a~out 0.9 to 5 parts, preferably 0.9 to
1.2 parts of acetone from separate containers and
through separate conduits, then premixing them
immediately prior to hydrolysis. It is necessary to
limit the contact time if small amounts of water are
present in the acetoneor in the atmosphere in contact
with the organohalosilanes, as the water present
causes hydrolysis of the organohalosilanes generating
acid which causes the acetone to polymerize. The
initial hydrolysis medium prior to the introduction of
the silane blend-acetone mixture contains from about
0 to 4.1 parts of acetone and preferably from 0.9
to 1.2 parts of acetone. The amount of water and
organic solvent can be as set forth hereinabove, with
preferably from about 3 to 3.5 parts of water and
2Q G.9 to 1.2 parts of organic solvent per part of the
total weight of the blend of organohalosilanes.
The temperature of the hydrolysis mixture
can be con-trolled by the rate of addition of the
reagents, or by external heat or by cooling if desired.
During hydrolysis, a temperature of between about 20C
to about 40C is preferred. After the addition of all
the reagents is completed, the mixture is generally
agitated for an additional period of time such as 15
to 30 minutes or more to allow for complete hydrolysis
of the organohalosilanes. The mixture is then allowed
to settle and the acid aqueous ~bottom) layer is drawn
off from the organic layer. Depending upon individual
desires, the organic layer can then he stripped of
solvent to a solids concentration of up to laO%. The
organic solvent may ~e stripped under reduced pressure
or atmospheric pressure. At this point, the resin may be
~2~70
60SI-409
p ,9"
bodied, i.e.,-build u~ ~ molecular weight, under total
refl~lx, by condensing and cross-linking silanol units,
with the aid of, for example, a catalyst such as iron
octoate or Celite ~ iatomaceous earth~ or mixtures
thereof, to a desired viscosity, preferably 5-12 cps.
at 25C at 20% by weight resins solids. Moreover,
resin impurities may be removed by filtration, using
for example, filtering aids such as Celite 5~5
(Diatomaceous earth, sold by Johns Manville), Fuller's
earth (calcium montmorillonitel, and mixtures of the
same, or simply ~y centrifugation. The resulting
silanol-containing organopolysiloxane resin has an
organo radical to silicon ratio of about 1.05 to 1.
Included among the water-immiscible organic
solvents used in the above-described process for
providing silicone resins are, for example, hydrocarbons
such as benzene, toluene, xylene and the like; esters
such as butyl acetate, ethyl acetate, ethers such as
diethylether and the like. Toluene is most preferred
because it is a good solvent and has a low boiling
point. In general, however, any water-immiscible
organic solvent, which is inert to the hydrolysis
reactants during hydrolysis and in which the hydrolyzate
is soluble to provide for its separation from the
aqueous layer, may be used.
Of course, through the process provided by
the present invention it is now possible to disperse
these heretofore water-immiscible resins in aqueous
media.
One of the classes of emulsifying agents
required for the water-based silicone resin emulsions
of the present invention are vinyl addition polymer
products, e.g., polyvinyl alcohol and/or carboxyvinyl
polymers. Such products are available, e.g., from
Monsanto Plastics and Resins Co., St. Louis, Missouri,
U.S.A., trademark GELYATOL and from B.F. Goodrich
1~6270
- 10 - 60SI 409
Chemical Co., Cleveland, Ohio, U.S.A., under its
trademark CARBOPOL , respectively. Polyvinyl alcohol
is an item of commerce. It is made by hy-rolyzing, with
acid or base, a polyvinyl ester, usually the acetate.
The degree of hydrolysis depends on the conditions.
"Completely hydrolyzed" polyvinyl alcohol usually
contains approximately 5% residual pendent acetate
groups. For the presentinvention, the extent of
residual pendent acetate groups can vary rather widely,
e.g., from about 5 to about 80%, but preferably from
about 5 to about 60%, meaning that the pendent hydroxyl
content will vary from about 20 to about 95% and
preferably from about 40 to about 95%. The carboxy-
substituted vinyl addition polymers are likewise
items of commerce. Such polymers are typically white
powders, having a slight acetic acid odor, and when
dispersed in water become viscous when neutralized,
e.g., with sodium hydroxide, or the other bases
mentioned balow. Suitable for purposes of this invention
are three materials, CARBOPOL M 934, 940 and 941. When
neutralized and made up in 0.2% solutions, these vary
in viscosity by virtue of differences in molecular
weight. The 934 generally falling in the range of
2,050-5,450 Cp; 940 in the range of 15,000-35,000 Cp;
and 941 in the range of 1,950-7,000 Cp in Brookfield
test apparatus run at 20 rpm and 25C by well known
procedures. A material of the type known as CARBOPOL
941 seems to be especially suitable for purposes of the
invention. Acidity is neutralized by reaction with a
base, e.g., an alkali metal or alkaline earth metal
hydroxide, carbonate, bicarbonate or a primary, secondary
or tertiary amine or ammonia, etc., before use.
The other class of required emulsifying agents
which are used in combination with the above-described
polymerized vinyl products are the anionic emulsifiers
such as sodium lauryl sulfate, sodium linear alkyl
60SI-409
--11--
benzene sulfonate, triethanol amine linear alkyl
benzene sulfonate, sodium alpha olefin sulfonate,
ammonium alkyl phenol ethoxylate sulfate, ammonium
lauryl ether sulfate, ammonium alkyl ether sulfate,
dialkyl ester of sodium sulfosuccinic acid, sodium
c~ erJe
i c~mcne sulfonate, ammonium xylene sulfonate, and
ammonium oleate, morpholinium stearate, dimethyl-
ammonium linoleate, and the like.
Illustrative nonionic emulsifiers are well
known, and include alkylphenoxypoly CethYlene oxyethanol),
trimethylnonylpolyethylene glycol ether, and, in
general, any of the n-alkyl monoethers which have been
A commercially available for a num~beg5~f~ars -- se~
e.g., the above mentioned U.5. ~,05~ 3~.
The water-based silicone resin emulsions
of the present invention can be made by any of several
methods. Ordinarily the order of addition of
ingredients is not critical. O~e suitable method calls
for the dispersîon of the vinyl addition polymer agent
2a in water with agitation and heat until the solids
- are dissolved. The water phase of the emulsion products
can also be added in two, three or more parts, as
desired. Ordinarily, from 0.5 to 10 parts by weight
vinyl addition polymer and 0.1 to 50 parts by
weight nonionic and/or anionic emulsifier per 100
parts by weight silicone resin solids will be effective
for emulsifying such resins in an aqueous system.
Those skilled in the art will be able to vary the
proportion of the constituent ingredient in order to
3a provide desirable resin emulsion formulations.
Additionally, optional ingredients such as
formalin can be used to these emulsions depending upon
a given desired end use without seriously detracting
from the properties of the water-based emulsion. ~n
example o~ a typical silicone resin ~hich can be used
in the emulsions and processes of the present invention
is SR-141 w~ich is available from the General Electric
12~270
60SI 409
-12-
Company.
The composition to be emulsified will then be
blended until uniform whereupon emuls~fication can ~e
induced by colloid milling of the composition or by
homogenization or blending of the composition.
A colloid mill found useful for producing
laboratory quantities of these water-based rein
emulsions is Manton-Gaulin Colloid Mill, Model 2A.
Such a mill has a 40 mil gap which i5 adjustable from
1 to 40 mils and can be operated at atmospheric
pressure or under a feed pressure of 5 to 40 psig N2.
1~ f course, it is contemplated that those skilled in
the art wîll be able to scale up ~ process of the
present invention in order to produce commercial
quantities of these water-based silicone emulsions.
The viscosity of any resulting emulsion
can be controlled ~y varying the amount of water
included in the blend. This can best be accomplished
by first forming a premix comprised of the vinyl addition
polymer and silicone resins along with parts of the water.
This premix can be emulsified by combining it with the
nonionic and/or the anionic emulsifier and the remaining
water. The accompanying examples demonstrate that the
water may also be added in three increments.
The organopolysiloxane resins which are utilized
in the following examples are comprised primarily of
trifunctional units of the formulae CFI3SiO1 5 (T units)
and (C6H51 siol 5 (T' units),; and di-functional units of
the formulae (CH3~2SiO (,D units), and (C6H5)2SiO (D' unitsl.
3a In the description of each resin, the term
silane (,P.B.W.) refers to parts by weight of the
requisite organohalosilane precursor of the resin's
functional units. Approximate weight percent silane
and mole percent silane values are given for the
35 convenience of those skilled in the art. The weight
percent siloxane value is indicative of the approximate
60SI-409
-13-
number of each type of siloxane units present in an
average resin molecule. The R to Si Ratio is an
expression used by those skilled in the art to ind~cate
the approximate relative number of organo radicals
associated ~ith each silicon atom and is a useful measure
of the degree of tri- and di-functionality in such
silicone resins.
SILICONE RESIN -
-
P.B.W. WT. ~ MOL % WT. %
10 UNITS SILANE SIL~NE SIL~NE SILOXANE
T 149.5 24.2 30 17.7
D 129 14.0 20 13.1
T' 211.5 37.4 30 34.23
D' 253 27.4 20 34.97
R to Si ~atio: 1.40 to 1.
SILICONE RESIN - B
~ , . .
P.B.W. WT. % MOL % WT. %
UNITS SILANE SILANE SILANE SILOXANE
T 149.5 8.1 10 5.51
D 129 27.9 40 24.36
T' 211.5 22.9 20 21.24
D' 253 41.1 30 48.89
R. i~ Si Ratio: 1.7 to 1.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
In order to more fully and clearly describe the
present invention, it is intended that the following
examples be considered as illustrative rather than
limiting the invention disclosed and clai~ed herein.
All parts are by weight.
124~6~70
- 14 - 60SI 409
Example 1
The silicone resin to be emulsified
was a solid, bodied resin hydrolysis product
comprised, of approximately, 35.1% methyl-
trichlorosilane, 15.2% dimethyldichlorosilane,
and 49.7% phenyltrichlorosilane, by weight.
To a 2-liter stainless steel beaker
equipped with an air stirrer there was added
150 g. of the solid silicone resin, 50 g. of an 85%
aqueous nonionic surfactant [50:50 alkylphenoxypoly-
(ethyleneoxyethanoltrimethylnonyl polyethylene
glycol ether], 300 g. of water, 100 g. of
mineral spirits, 100 g. of xylene and 100 g. of
10% polyvinyl alcohol aqueous solution (Gelvatol
20/90). The premix was blended until uniform,
then colloid milled (4 mil gap at atmoc-pheric
pressure). The resultant emulsion had a viscosity
of 1420 cps., solids content of 24.7% and was
uniformly milky white in appearance. When
centrifuged for 30 minutes at 3000 RPM, a 40 cc.
sample was found to have no visible separation --
top or bottom. Coating the composition on
an aluminum panel produced a uniform coating
free of the creep noticed when the resin was
emulsified with only the nonionic component in the
blend of the Example.
Example 2
A blend of 187 g. of dry powdered
silicone resin powder as described in
Example 1, 60 g. of titanium dioxide, 19 g.
270
- 15 - 60SI 409
of nonionic emulsifier (Example 1), 85 g. of 10%
polyvinyl alcohol solution, 282 g. of water,
37 g. of perchloroethylene solvent, and
94 g. of N-propoxy-propanol was uniformly
mixed. Thus the resin water base premix was
changed to 100 g. of 10% polyvinyl alcohol
solution and 100 g. of odorless mineral spirits.
Next was added 10 g. of methylphenylsilicone
oil and 1/2 g. of iron octoate catalyst.
The premix was blended in a stainless steel
beaker with an air-drive stirrer until uniform.
Then it was colloid milled through a mill set at
4 mil gap. The resulting paint containing
emulsified silicone resin was found to contain
28.6% solids and have a viscosity of 1034 cps.
When a 40 ml. sample was centrifuged for
30 minutes at 3000 rpm, there was no visible
separation, to or bottom. When an aluminum panel
was coated with the paint and cured for 1 hour at
105C., a uniform coating, free from voids, was obtained.
Example 3
A carboxylated high molecular weight
vinyl addition polymer (B.F. Goodrich Company,
Carbopol 941~, 2 g., was dispersed with rapid
agitation in 940 g. of deionized water at 50C.
There was then added 2.8 g. of 6-acetoxy-2,4-
dimethyl-m-dioxane presservative (Givandan Corp.,
Clifton, New Jersey, U.S.~., Giv. Gard DXN~
and 8.3 g. of 10~ aqueous sodium hydroxide solution.
Next was added 81 g. of 10% a~ueous sodium hydroxide
solution. Next was added 81 g. of the 85%
active nonionic emulsifier blend and 1757 g.
of a solution of silicone resin.
i2'~Ç;270
6OSI-409
-16-
The silicone resin was an 80% silicone resin
solids compositions, VM & P naptha solvent, and was
primarily comprised of the hydrolysis products of 8.1%
methyltrichlorosilane; 27.9% dimethyldichlorosilane;
22.~% phenyltrichlorosilane; and 41.4% diphenyldichloro-
silane C5ilicone Resin - B, above~.
The mixture was dispersed with highagitation.
Then 80 ~. more of nonionic emulsifier blend
(Example 12 and lOQ g. of water wa.s added. The premix
lQ wa5 blended and colloid milled through a 5 mil gap at
atmospheric pressure. The resulting milky white
emulsion had a viscosity of 1573 cps., a soiids
content of 51.6% and a pH of 5.8. When a 40 ml.
portion was centrifuged for 3Q min. ~t 3000 rpm, less
than 1 ml. of separation was noticed on either top
or bottom.
EXAMPLE ~
There were ~lended 0.5 g. of preservative
(Giyandan Corp., Giv Gard DXN~, 0.7 g. of car~oxylated
2Q high molecular weight vinyl addition polymer
~Car~opol 941L, 3 g. of 10% aqueous sodium hydroxide
solution, and 366.8 g. of water at 60C. for 1 hour,
to disperse and neutralize the carhoxy vinyl polymer.
Six hundred grams of silicone resin solution were
~lended with 30 g. of an 85% active nonionic
emulsifier solution ~Example 1~.
S;/ ,'co r)e,
The -s-i-~it~ resin solution was a 50% resin
solids solution in toluene and was primarily comprised of
the hydrolysis products of 4a mole ~ of methyltri-
3Q chlorosilane, 30 mole percent of phenyltrichlorosilane,2Q mole % of diphenyldichlorosilane (~Silicone Resin - A,
aE: oYel -
Once the resin solution and the emulsifier were
uniformly blended, the neutralized carboxy Yinyl
polymer solution was added. The premix was blended and
then passed through a colloid mill set at a 5 mil gap
6osI-4Q9
-17-
and under atmospheric pressure. The resulting emulsion
of silicone resin had a solids content of 33.1%,
a pH of 6.0 and a viscosity of 30QQ cps. When a 40
ml. sample was centrifuged for 30 min. at 3000 rpm,
no visible separation was noted. The emulsion was
aged one month at 50C in an air circulating oven
and the shelf stability was found to be excellent.
EXAMPLE ~
~ To 600 g. of the silicone resin solution of
Example ~was added lOa g. of polyvinyl alcohol
solution (Example l). The premix was blended and a
solution containing 5 g. of sodium lauryl sulfate
~anionic surfactant~ in 295 g. of water was charged.
The premix was blended for one hour and then colloid
milled at a 6 mil gap, atmospheric pressure. The
emulsion was found to have a viscosity of lO00 cps,
pH of 7.0, and solids content of 31.8%. When a 40
ml. sample was centrifuged at 3000 rpm for 30 minutes,
2a there was not visihle separation, top or bottom. When
a sample of the polyvinyl alcohol-containing emulsified
silicone resin was aged in a 50C oven for one month,
shelf stability was found to be excellent.
EXAMPLE
To 600 g. of the silicone resin of Example~
was added lO0 g. of the polyvinyl alcohol solution of
Example l and the mixture was blended. Then was added a
solution of 2 g. of the potassium salt of dodecylbenzene
sulfonic acid (anionic) dissolved in 298 g. of water.
The mixture was ~lended for one hour, and the colloid
milled at 6 mil gap and atmospheric pressure. The
emulsion obtained had a viscosity of 4100 cps, a pH of
6.3 and a solids content of 3.12~. When a 40 ml. sample
was centrifuged for 30 min. at 3000 rpm, no visible
separation was noted--only surface skinning due to drying.
A sample placed in a 50C. oven for one month, and it
aged well.
60SI-409
7 -18-
EXAMPLE-~r
To 600 g. of the silicone resin of Example-~was
added 14.1 g. of oleic acid and the mixture was well
blended. Then a solution was added comprising 0.2 g.
carboxy vinyl polymer (Carbopol 941~, 3 g. of 28~ aqueous
ammonium hydroxide and 382.7 g. of water. The premix
was stirred for one hour and then colloid milled with a
6 mil gap at atmospheric pressure. The resulting
emulsion had a viscosity of 290Q cps, a pH of 8.8 and a
solids content of 31.9~. When a 40 ml. sample was
centrifuged for 3Q minutes at 30Q0 rpm no visible
separation was noticed. A sample was aged at 50~C
for one month and shelf stability was found to be
excellent.
Silicone resins of the type used herein are
recommended and utilized in the preparation of various
paints and coatings. Environmental restrictions are
foxcing industry to install either costly solvent
recovery systems or switch to less environmentally-
sensitïYe solvent systems. Incorporation of resin
solut~ons into water based systems are effective
solutions to governmental requirements for less
pollution. Emulsification of existing silicone resin
compositions into water based systems has not been too
easily achieved heretofore, but is readily accomplished
according to the present invention. The vinyl addition
polymers used herein permit formulated emulsions to
dry without the formation of "fish eyes" and creeping
associated with the use of ætrictly nonionic suxEace
actiYe agent systems.
Many variations will suggest themselves to
those skilled in the art in light of the ahoye-detailed
descxiption. All such o~yious variations are within
the full intended scope of the appended claims~
