Water based resin emulsions

Water-based silicone resin emulsions are provided comprising an organopolysiloxane resin or mixture of resins which may include a solvent carrier, and a combination of emulsifying agents including cellulosic-type and anionic surfactant-type emulsifiers as well as an amount of water sufficient for providing a water-based emulsion having a desired viscosity and silicone resin solids content by weight.

BACKGROUND OF THE 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-based 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 such 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 been found to be particularly useful in the paint industry which 
is continually seeking coating formulations which offer premium 
properties. Silicone resins solutions have previously been used in the 
paint coatings industry as vehicles and binders which are a necessary part 
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 been discouraged 
due to escalating costs for organic materials and increased concern for 
environmental considerations. Organic solvent based silicone resins often 
required the use of costly and cumbersome pollution abatement procedures 
and equipment. 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 
invention 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 be used in high temperature-resistant coatings and will 
generally outperform conventional 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 provided in U.S. Pat. Nos. 4,028,339 and 4,056,492 (both 
issued to Merrill) are examples of resins which can be made part of the 
water-based emulsion compositions of the present invention. Both of these 
patents are hereby incorporated by reference. 
Previously known silicone resin emulsions have been successfully 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 emulsifier for 
each nine parts of resin solids. When this type of emulsion technology is 
attempted in conjunction with the resin coating formulations 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. 
The present invention, on the other hand, utilizes an emulsion system based 
upon a combination of anionic emulsifiers and certain methylcellulose 
ether compositions. The total emulsifier requirement for the emulsions of 
the present invention is generally in the range of approximately 0.5 to 2 
percent based upon the weight of the silicone resin solids as compared to 
approximately 11% in the aforementioned emulsions. Furthermore, the 
reduction in organic emulsifier still enables the silicone resin film to 
function satisfactorily as a coating. Additionally, it seems that the use 
of methylcellulose agents enables the water-based compositions to coat out 
more uniformly as compared to the above-described emulsions utilizing 
nonionic emulsifiers. 
It is therefore a primary object of the present invention to provide 
water-based emulsions of organopolysiloxane resins which are useful in 
coating formulations. 
It is another object to provide an emulsifier system comprising a 
combination of anionic and methyl cellulose ether emulsifiers 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 
silicone 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 
monofunctional units having the general formula R.sub.3 SiO.sub.0.5, zero 
to 60 percent by weight difunctional units of the formula R.sub.2 SiO, 
zero to 100 percent by weight trifunctional units having the general 
formula RSiO.sub.1.5, and zero to 60 percent by weight tetrafunctional 
units having the general formula SiO.sub.2. As those skilled in the art 
recognize, there must be present at least ten mole percent of 
trifunctional units, tetrafunctional units, or mixture thereof in order to 
be a resinous siloxane material. Accordingly, the emulsions of the present 
invention must contain siloxanes having at least ten mole percent, and 
preferably at least fifteen mole percent, of such trifunctional and 
tetrafunctional units. In the above forumlae 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 organopolysiloxane 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 silicone atom. It is to be understood 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 CH.sub.3 SiO.sub.1.5 units, zero 
to 35 percent (CH.sub.3).sub.2 SiO units, 15 to 65% (C.sub.6 
H.sub.5)SiO.sub.1.5 units, and zero to 50 percent (C.sub.6 H.sub.5)SiO 
units, wherein there is present, approximately, 1.0 to 1.8 organic 
radicals for each silicone 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 a approximately 20 to 90 
percent by weight silicone resin solution in an organic solvent such as 
toulene 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 adjust 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 4.0 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 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 a cellulosic emulsification agent in combination with 95 to 5 
percent by weight of an anionic surfactant or emulsifying agent. For 
example, 70 to 75 percent by weight cellulosic emulsifier and 25 to 30 
percent 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. When an 
effective amount of such combinations of emulsifying agents are combined 
with the organopolysiloxane 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 
solids content by weight in the resulting emulsion. As stated, although 
the amount of water is not critical there will ordinarily be approximately 
25 to 500 parts by weight and more preferably 50 to 300 parts by weight of 
this water per 100 parts of the organopolysiloxane resin. If more than 100 
parts by weight resin is present per 25 parts by weight water, 
emulsification will be difficult. If less than 100 parts by weight resin 
is present per 500 parts by weight water, there will be insufficient resin 
present in the emulsion to impart the desired properties to the end 
product. 
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. 
DESCRIPTION OF THE INVENTION 
Silicone 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 composition 
of the resin can be varied by changing the proportions of the constituent 
organohalosilanes to be hydrolyzed. An exemplary resin might start with a 
blend of about 60 mole percent methyltrichlorosilane, about 35 mole 
percent of phenyltrichlorosilane and about 5 mole percent of 
dimethyldichlorosilane in the presence of water, acetone and a 
water-immiscible organic solvent. In general, this hydrolysis medium could 
contain from about 1.7 parts to 10 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 various components of the hydrolysis mixture can be added concomitantly 
or separately in any desired order. Generally, the organohalosilanes are 
added to the mixture of water, acetone and organic solvent. Preferably, 
when this method is used a proportion of from 2 to 6 parts of water, about 
0.3 to about 2 parts of acetone, and about 0.6 to about 2 parts of organic 
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 hydrochloric acid which is formed during the hydrolysis 
reaction. A strong hydrochloric acid solution is undesirable in this 
example as the hydrochloric acid causes acid polymerization of the acetone 
forming polymerization products which add undesirable color to the product 
and have a deleterious effect on the physical properties of the product. 
A preferred method to prepare organopolysiloxane resins which may be used 
in this invention is the dual feed process. The dual feed process 
comprises feeding the blend of organohalosilanes and from about 0.9 to 5 
parts, preferable 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 acetone or 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 0.9 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 controlled by the rate of 
addition of the reagents, or by external heat or by cooling if desired. 
During hydrolysis, a temperature of between about 20.degree. C. to about 
40.degree. C. 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 be stripped of solvent to a 
solids concentration of up to 100%. The organic solvent may be stripped 
under reduced pressure or atmosphere pressure. At this point, the resin 
may be bodied, i.e., build-up of molecular weight, under total reflux, by 
condensing and cross-linking silanol units, with the aid of, for example, 
a catalyst such as iron octoate or Celite (diatomaceous earth) or mixtures 
thereof, to a desired viscosity, preferably 5-12 cps. at 25.degree. C. at 
20% by weight resins solids. Moreover, resin impurities may be removed by 
filtration, using, for example, filtering aids such as Celite 545 
(diatomaceous earth, sold by Johns Manville), Fuller's earth (calcium 
montmorillonite), and mixtures of the same, or simply by 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 for 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 methylcellulose 
ether products. Suitable methylcellulose ether products are available from 
Dow Chemical Company under its trademark METHOCEL. These cellulose ethers 
are derived from cellulose and contain repeating anhydroglucose units. 
Methylcellulose or cellulose methyl ether is derived from cellulose by 
conversion to alkali cellulose which is then reacted with methyl chloride. 
Hydroxypropyl methylcellulose or propylene glycol ether is similarly 
manufactured but utilizes propylene oxide in addition to the methyl 
chloride reactant. 
Additionally, a nonionic water-soluble cellulose ether known as KLUCEL 
hydroxy propyl cellulose is manufactured by Hercules, Inc. 
The other class of required emulsifying agents which are used in 
combination with the above-described cellulose ether products are the 
anionic emulsifiers such as sodium lauryl sulfate, sodium linear alkyl 
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 cumene sulfonate, and ammonium xylene 
sulfonate. 
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. One suitable method calls for the dispersion 
of the cellulose ether agent 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 1.0 
parts by weight cellulose ether and 0 to 1 parts by weight 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 ingredients in 
order to provide desirable resin emulsion formulations. 
Additionally, optional ingredients such as formalin can be added to these 
emulsions depending upon a given desired end use without seriously 
detracting from the properties of the water-based emulsion. Of course, 
materials such as talc or mica, which are utilized in green tire 
lubricants to provide channels for release of air, are not included within 
the scope of optional additives for practicing the present invention. 
Furthermore, those skilled in the art will appreciate that other compounds 
such as n-alkyl monoethers of polyethylene glycols desirably are not 
included in the emulsions of the present invention as they deleteriously 
affect high temperature stability. An example of a typical silicone resin 
which can be used in the emulsions and processes of the present invention 
is SR-141 which is available from the General Electric Company. 
The composition to be emulsified will then be blended until uniform 
whereupon emulsification can be induced by colloid milling of the 
composition or by homozenization or blending of the composition. 
A colloid mill found useful for producing laboratory quantities of these 
water-based resin emulsions is Manton-Gaulin Colloid Mill, Model 2A. Such 
a mill has a 40 mil gap which is adjustable from 1 to 40 mils and can be 
operated at atmospheric pressure or under a feed pressure of 5 to 40 psig 
N.sub.2. Of course, it is contemplated that those skilled in the art will 
be able to scale up the 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 by varying the 
amount of water included in the blend. This can best be accomplished by 
first forming a premix comprised of the cellulose ethers and silicone 
resins along with part of the water. This premix can be emulsified by 
combining it with 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 tri-functional units of the formulae CH.sub.3 
SiO.sub.1.5 (T units) and (C.sub.6 H.sub.5)SiO.sub.1.5 (T' units); and 
di-functional units of the formulae (CH.sub.3).sub.2 SiO (D units), and 
(C.sub.6 H.sub.5).sub.2 SiO (D' units). 
In the description of each resin, the term silane (P.B.W.) refers to parts 
by weight of the requisite organolalosilane precursor of the resin's 
functional units. Approximate weight percent silane and mole percent 
silane values are given for the convenience of those skilled in the art. 
The weight percent siloxane value is indicative of the approximate 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 indicate 
the approximate relative number of organo radicals associated with each 
silicon atom and is a useful measure of the degree of tri- and 
di-functionality in such silicone resins. 
______________________________________ 
P.B.W. WT. % MOL % WT. % 
UNITS SILANE SILANE SILANE SILOXANE 
______________________________________ 
Silicone Resin - A 
T 149.5 10.6 13 7.34 
D 129 25.8 37 22.86 
T' 211.5 26.5 23 24.96 
D' 253 37.1 27 44.84 
R to Si Ratio: 1.64 to 1. 
SILICONE RESIN - B 
T 149.5 24.2 30 17.7 
D 129 14.0 20 13.1 
T' 211.5 34.4 30 34.23 
D' 253 27.4 20 34.97 
R to Si Ratio: 1.40 to 1. 
SILICONE RESIN - C 
T 149.5 17.1 20 12.36 
D 129 29.6 40 27.31 
T' 211.5 24.3 20 23.80 
D' 253 29.0 20 26.53 
R to Si Ratio: 1.6 to 1. 
SILICONE RESIN - D 
T 149.5 52.6 50 35.17 
D 129 3.8 5 3.88 
T' 211.5 43.6 45 60.95 
D' 253 0 0 
R to Si Ratio: 1.05 to 1. 
SILICONE RESIN - E 
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 to Si Ratio: 1.7 to 1. 
______________________________________

DESCRIPTION OF THE PREFERRED EMBODIMENT 
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 claimed herein. All parts are by 
weight. 
EXAMPLE 1 
Twenty grams of Methocel A-25 by weight cellulose powder were charged to 
500 grams of water. Methocel A-25 is methylcellulose available from Dow 
Chemical Company, and exhibits a characteristic viscosity of approximately 
25 centipoise at 20.degree. C. when in a 2% aqueous solution. The 
methylcellulose was dispersed with agitation and heated to 75.degree. C. 
to dissolve the solids. During heating, approximately 150 grams of water 
were lost. Sixty grams of additional water were added to the dispersion 
thereby providing an approximately 4.9% methylcellulose solution. 
The silicone resin to be emulsified was designated as Silicone Resin-A and 
was a 60% by weight resin solution in toluene. The resin itself was the 
bodied resin hydrolysis product comprised of, approximately, 10.6% 
methyltrichlorosilane, 25.8% dimethyldichlorosilane, 26.5% 
phenyltrichlorosilane, and 37.1% diphenyldiclorosilane by weight. The 60% 
solution of Silicone Resin-A had an approximate viscosity of 200 
centipoise at 20.degree. C. 
Silicone Resin-A has been described in the aforementioned table. 
After the methylcellulose solution had been prepared it was combined with 
Silicone Resin-A, water, sodium lauryl sulfate and formalin to yield the 
following blend. 
______________________________________ 
Material Amount by Weight 
______________________________________ 
Silicone Resin-A 60% 
Water 39.39% 
Methocel A-25 0.27% 
Sodium Lauryl Sulfate 
0.16% 
Formalin 0.18% formulation 
______________________________________ 
In the above described formulation, Methocel A-25 is given in percent 
methylcellulose powder contained in the blend without regard to the water 
of solution. The mixture was blended until uniform and then colloid 
milled. The colloid mill had a 10 mil gap at atmospheric pressure. The 
milling process resulted in a silicone emulsion having the following 
properties: 
______________________________________ 
% Silicone Solids 37% 
Viscosity (Brookfield 
1410 Centipoise 
RVF at 25.degree. C.) 
______________________________________ 
EXAMPLE 2 
A 1.25% methylcellulose solution was prepared by adding 25 grams of 
Methocel A4M (a methylcellulose powder having a 2% aqueous solution 
viscosity of 4000 centipoise at 20.degree. C.) to 2000 grams of water. The 
methylcellulose powder and water were blended at elevated temperature 
until the powder was completely dispersed. Additional water was added to 
replace water lost through heating so that the 1.25% methylcellulose 
solution was obtained. 
Silicone Resin-B is a 50% silicone resin solids composition in toluene and 
is primarily comprised of the hydrolysis products of 30% 
methyltrichlorosilane, 30% phenyltrichlorosilane, 20% 
dimethyldichlorosilane and 20% diphenyldichlorosilane, as given by mole 
ratios. Silicone Resin-B has been described in the aforementioned Table. 
To 1420 grams of the 1.25% methylcellulose solution was added 4200 grams of 
Silicone Resin-B. The resin-methylcellulose mixture was blended until a 
uniform composition was obtained. In a separate container a blend of 1250 
grams water, 11 grams sodium lauryl sulfate and 19 grams formalin was 
obtained. This second blended mixture was then added to the 
Resin-B/methylcellulose blend and agitated well. Next the combined blend 
was colloid milled, again the colloid mill had a 10 mil gap at atmospheric 
pressure. The resulting emulsion was paste-like and was diluted with 600 
grams additional water to yield a final product having the properties: 
______________________________________ 
% Silicone Solids 28.6% 
Viscosity 2200 Centipoise 
______________________________________ 
EXAMPLE 3 
Since the emulsions prepared in Examples 1 and 2 had viscosities greater 
than 1000 centipoise, emulsions having lower viscosities which were 
therefore suitable for other purposes were prepared in the following 
manner. 
A cellulosic solution was prepared for this example by combining 40 grams 
Methocel A-25 (methylcellulose powder described above) and 40 grams 
Methocel E-50 (which is a hydroxypropyl methylcellulose powder, having a 
nominal 2% aqueous solution viscosity of 50 centipoise at 20.degree. C.), 
dispersed in 2000 grams water to yield a 4% cellulosic solution. 
To 4818 grams of Silicone Resin-A which was utilized in Example 1, there 
was added 1106 grams of the 4% cellulosic solution; this mixture was 
blended until uniform. Meanwhile, a second solution was prepared from 2064 
grams water, 13 grams sodium lauryl sulfate and 14 grams formalin. This 
second solution was blended at room temperature until uniform whereupon 
800 grams of this solution was added to the emulsion premix containing 
Silicon Resin-A. This final mixture was blended until uniform and then 
colloid milled at atmospheric pressure with a 10 mil colloid mill gap. The 
resulting emulsified resin paste was dispersed in the remaining second 
solution. After blending, the resulting silicone resin emulsion had the 
properties: 
______________________________________ 
% Silicone Solids 36.7% 
Viscosity 380 Centipoise 
______________________________________ 
Additionally, after two months shelf-aging, very little separation was 
noted and only mild agitation was necessary to redisperse the emulsion. 
EXAMPLE 4 
A cellulosic solution was prepared by combining 7.2 grams Methocel A-25 and 
7.2 grams Methocel F-50 in 180 grams water. The solids were dispersed with 
agitation at 80.degree. to 90.degree. C. and then rapidly cooled to room 
temperature by charging 180 grams of ice water to the blend. Once the 
cellulose solution was uniform, it was added to 2160 grams of Silicone 
Resin-C solution. Silicone Resin-C is 80% silicone solids in toluene, and 
is the resin hydrolysis product of, approximately, 20% 
methyltrichlorosilane, 40% dimethyldichlorosilane, 20% 
phenyltrichlorosilane, and 20% diphenyldichlorosilane as given by mole 
ratios. Silicone Resin-C has been described in the aforementioned table. 
This cellulose-resin premix was blended for half an hour. Meanwhile an 
aqueous solution was prepared by combining 5.2 grams sodium lauryl 
sulfate, 6.2 grams formalin and 1055 grams water. This aqueous solution 
was then added to the cellulose-resin mixture and blended for an 
additional 45 minutes. When the mixture was uniform it was emulsified by 
passing through a colloid mill having an 8 mil gap at atmospheric 
pressure. The resulting silicone resin emulsion was found to have the 
following properties: 
______________________________________ 
% Silicone Solids 49.0% 
Viscosity 2500 Centipoise 
pH 6.5 
______________________________________ 
EXAMPLE 5 
As in Example 4, 7.2 grams of each of Methocel A-25 and Methocel F-50 were 
dispersed in 180 grams water with agitation; the mixture was again cooled 
rapidly to room temperature by charging 180 grams ice water to the blend. 
This uniform cellulosic solution was added to 2170 grams of Silicone 
Resin-D, and this premix was blended for a half hour. Silicone Resin-D is 
a highly trifunctional, hard resin which is a useful vehicle for pigmented 
coatings and is a 60% silicone solids in toluene solution. Resin-D is the 
resin hydrolysis product of, approximately, 50 parts 
methyltrichlorosilane, 45 parts phenyltrichlorosilane and 5 parts 
dimethyldichlorosilane as given by mole ratios. Silicone Resin-D has been 
described in the aforementioned table. Simultaneously, as aqueous solution 
containing 1055 grams water, 5.4 grams sodium lauryl sulfate, and 6.2 
grams formalin. This aqueous solution was then mixed with the resin premix 
and the combination was blended for approximately 30 minutes. The uniform 
mixture was then emulsified with a colloid mill having an 8 mil gap at 
atmospheric pressure. The resulting emulsion was found to contain 30.0% 
silicone solids, 6.1 pH and a viscosity of 385 centipoise at 20.degree. C. 
EXAMPLE 6 
A cellulosic preblend was provided by mixing 4 parts each of Methocel F-50 
and Methocel A-15 with 100 grams of water which was then heated to 
approximately 80.degree. C. till the methylcellulose and 
hydroxyoropylcellulose powders were dispersed whereupon 100 grams of ice 
water was charged to cool the mixture. To this cellulosic solution was 
added 1200 grams of Silicone Resin-E which is an 80% resin solids in VM&P 
naptha solution which is useful as a silicone resin vehicle for heat 
resistant coating formulations. Silicone Resin-E is the resin hydrolysis 
product of, approximately, 8 parts methyltrichlorosilane, 23 parts 
phenyltrichlorosilane, 28 parts dimethyldichlorosilane, and 41 parts 
diphenyldichlorosilane by weight. Silicone Resin-E has been described in 
the aforementioned table. 
Next, an aqueous solution was prepared by combining 3 grams sodium lauryl 
sulfate and 3.4 grams formalin with 585 grams water. This aqueous solution 
was added to the cellulose-resin premix and blended for approximately 30 
minutes. The uniform mixture was then emulsified on a colloid mill having 
an 8 mil gap at atmospheric pressure. The resulting emulsion was found to 
have 49.0% solids content, 6.5 pH, and a viscosity of 2500 centipoise at 
20.degree. C. 
Thus it is evident that a wide variety of silicone resins can be emulsified 
by the process of the present invention so that they are compatible with 
the environmentally attractive water-based systems discussed above. 
EXAMPLE 7 
Another water-based silicone resin emulsion can be prepared in the 
following manner: 7.2 parts Methocel A25 and 7.2 parts Methocel F50 are 
slowly charged to a vessel containing 180 parts water which has been 
preheated to 80.degree. to 90.degree. C. Methocel is a trademark of Dow 
Chemical Company. Methocel A25 is a methylcellulose powder which exhibits 
a characteristic viscosity of approximately 25 centipoise at 20.degree. C. 
when in a 2% aqueous solution. Methocel F50 is a hydroxypropyl 
methylcellulose powder which exhibits a characteristic viscosity of 
approximately 50 centipoise at 20.degree. C. in a 2% aqueous solution. The 
cellulosic powders are dispersed in the preheated water with agitation and 
the blend is cooled rapidly to 20.degree. while adding an additional 180 
parts water. To this dispersion is added the silicone resin which is to be 
emulsified. The silicone resin may be the bodied resin hydrolysis product 
of, approximately, 30M% methyltrichlorosilane, 30M% phenyltrichlorosilane, 
20M% dimethyldichlorosilane and 20M% diphenyldichlorosilane as given in 
molar ratios. This bodied resin is cut with toluene to achieve a 60% 
silicone resin solids content. 2160 parts of this resin is added to the 
cellulosic dispersion prepared above along with 1055 parts additional 
water, 5.4 parts sodium lauryl sulfate and 6.2 parts formalin. The entire 
mixture is stirred until uniform whereupon it is colloid milled at 
atmospheric pressure with an 8 mil gap to form the emulsion. Stirring is 
continued until room temperature is reached. The water-based silicone 
resin emuilsion produced by the above procedure had an approximate 
silicone solids content of 30.7% and a viscosity of approximately 650 
centipoise at 20.degree. C.