GB2085903A - Water dispersible silicone resins for water based applications - Google Patents

Abstract

The present invention provides self-emulsifiable silicone compositions which are readily dispersible in aqueous media and useful in coating applications and which comprise 100 parts by weight of a silicone having polymeric units selected from RSiO1.5, R2SiO, R3SiO0.5 and SiO2 units wherein R is H or a C1-20 hydrocarbon radical, preferably methyl and phenyl; and 1 to 50 parts by weight of a surface active agent or blend which is completely soluble in the silicone resin and is effective for dispersing the resin composition in aqueous media.

Description

SPECIFICATION Water dispersible silicone resins for water based applications The present invention provides water dispersible silicone resin compositions which are particularly useful for water based coating applications.

Silicone resins are organopolysiloxane compositions which offer premium properties in a number of applications, including the paint and coating industry. Incorporation of silicones into conventional coating systems offers extended flexibility to the formulator who may then.offer a product exhibiting exceptional durability as well as an ability to withstand extreme environmental weathering conditions such as heat, cold and exposure to ultraviolet radiation.

These silicone resins are manufactured primarily from organotrichlorosilanes and diorganodichlorosilanes, and are ordinarily comprised of difunctional (D or D') units having the average formula R2SiO, and trifunctional (T or T') units having an average formula RSiO15. In these formulas, R represents the same or independently different monovalent hydrocarbon radicals, which may or may not be halogen substituted. Ordinarily R will represent alkyl radicals such as methyl, ethyl, propyl, butyl, etc.; aryl radicals such as substituted or non-substituted phenyl radicals; vinylic and allylic radicals, and such substituted alkyl radicals as trifluoropropyl. Those skilled in the art will recognize that there are numerous silicone resins falling within the above general description which find utility in the coating industry.

Silicone resins are normally supplied to a coating formulator in some type of organic solvent such as mineral spirits, toluene, xylene, cyclohexane, etc, and are generally classified according to percentage of solid silicone material per one hundred percent of the total silicone-solvent mixture. There are available, however, certain high-solids, i.e. nearly solventless, silicone resins, certain of which will also find utility in the present invention.

It is to be noted, however, that in recent years the use of solvents is being discouraged.

Organic solvents are becoming more expensive while at the same time expensive pollution abatement procedures are required. Furthermore, in cases where the solvent must be removed from a system prior to use or cure, increasingly expensive thermal energy need be expended in the recovery of the solvent.

Thus there has been a trend in the coatings industry to formulate water based rather than solvent based coatings which would eliminate some of the aforementioned problems. Silicone resins become an important part of these new formulations due to their ability to supply premium properties. Thus it is necessary that the silicone resins be provided in a form which is totally compatible with new water based systems. In the past, resinous silicone materials have been supplied in the form of emulsions. These can be either of two types, namely the water-inoil emulsion or the more common oil-in-water emulsion where the silicone resin (oil phase) is dispersed in the continuous aqueous phase. These emulsions are provided by combining various proportions of the oil and water phases with emulsifiers or other surface active agents.

Additionally, however, it is necessary that a certain amount of energy be applied to the system in order to disperse the divergent phases. This can sometimes be accomplished by blending in a mixer, but a common procedure is to utilize a colloid mill. Examples of conventional silicone emulsions can be found in the copending U.S. application of Traver and Thimineur, S.N.

164,880 filed July 1, 1 980 and which is hereby incorporated by reference.

The present invention provides silicone resins which are self-emulsifiable in such water based systems without the necessity of conventional emulsion technology. That is to say, the instant compositions are silicone resins which are combined with certain emulsifying or surfactant agents which are wholly soluble therein and which are effective for dispersing the resin-oil phase in a continuous aqueous phase without the application of additional external energy beyond moderate agitation which can be provided by simple stirring or shaking if necessary.

U.S. Patent 4,052,331 (Dumoulin) which issued October 4, 1977 discloses surface active compositions which can be utilized to emulsify diorganopolysiloxanes. The processes disclosed by Dumoulin are to be distinguished from the self-emulsifiable silicone resins of the present invention since Dumoulin's process requires, in addition to n-alkyl monoethers of polyethylene glycol, a sodium dialkylsulphosuccinate compound, at least one acid such as oleic or linoleic acid, as well as at least one amine compound such as triethanolamine. Not only do the selfemulsifiable silicone resins of the present invention not require these ingredients, it is to be noted that Dumoulin's emulsions require that there be present no more than 1 5 weight percent of the organosilicon material based upon the total weight of the emulsifier-silicone mixture.The compositions and processes of the present invention enable the application of much higher percentages of silicone solids.

U.S. Patent 3,428,560 (Olsen) which issued February 18, 1 969 discloses a self-emulsifiable yarn-lubricating composition of isocetyl stearate, sodium di-(2-ethyl hexyl) sulfosuccinate in combination with a non-ionic emulsifying agent. Olsen discloses the use of certain surface active agents to self-emulsity lubricants such as long chain fatty acids and although it discloses the use of certain non-ionic emulsifiers, it has no particular applicability to self-emulsifiable water-borne coatings of silicone resins.

The self-emulsifiable silicone resin composition of the present invention is comprised of two main constituents. The first constituent is an organosilicon compound which is ordinarily an organopolysiloxane polymer. The second major constituent is the surface active agent or blends of such agents which usually are emulsifiers which are completely soluble in the organosilicon compound. Ordinarily per 100 parts of the organosilicon compound there will be present from 1 to 50 parts and preferably 10 to 40 parts by weight of the surface active agent.

The organosilicon compound which has approximately 0.8 to 2.5 organic groups per silicon atom is comprised primarily of units selected from the group consisting of RSiO1 5, and R2SiO units but there may be present moderate amounts of other polymeric units such as R3SiOo 5, and SiO2 units. In these formulas R represents either hydrogen or a monovalent hydrocarbon radical having from I to 20 carbon atoms. Among the hydrocarbon radicals, the silicon resins of the pesent invention will ordinarily be comprised of methyl and phenyl radicals, however, there maybe also utilized other alkyl and aryl radicals as well as such reactive groups as vinyl, allyl, hydroxyl radicals.Of particular interest are those organosilicon compounds cpmprised of approximately 0 to 100 mole percent CH3SiO1 5 units, 0 to 60 mole percent C6G5SiOf 5 units, 0 to 50 mole percent (CH3)2SiO units, and 0 to 50 mole percent (C6H5)2SiO units. Although these are the preferred polymeric constituents it is also intended that the present invention include those compositions having 0 to 70 mole percent SiO2 units, and 0 to 70 mole percent R2R'SiOo5 units where R is defined above and R' is either the same as R or can also be a hydrogen atom or a phenyl or vinyl radical. These organosilicon compounds are often commercially prepared in hydrocarbon solvents such as naptha, toluene, xylene or mineral spirits.The silicone resins ordinarily comprise approximately 30 to 95 percent by weight of a solution in these solvents and could have a viscosity of approximately 10 to 10,000 centipoise at 25"C. Those skilled in the art will recognize that the various percent solid solutions and viscosities will relate to the final properties of a coating composition and are selected in accordance with the intended purpose of the coating. However, these properties do not influence the self-emulsifying process of the present invention. Thus the present invention is effective for emulsifying both silicone resins as well as silicone resin solutions. It is understood however that the amount of solvent should be kept to a minimum due to the environmental and economic concerns discussed above.

The surface active agents which have been found to be useful in the compositions and the processes of the present invention may be selected from the class consisting of non-ionic polyethoxylated esters and ethers, cationic dimethyl dicocoammonium chloride and polyoxyethylene 5 tallowamine, and anionic phosphated cetyl ethers or amine salts of dodecylbenzene sulfonic acid. This broad catagory of effective surface active agents includes those which are completely soluble in the aforementioned organosilicon compound and will disperse the silicone resin in an aqueous medium upon introduction of the self-emulsifiable silicone resin therein.It is to be noted that these surface active agents or blends of such agents have a hydrophiliclipophilic balance (HLB) value which is greater than 8 and is therefore effective for providing an emulsion wherein the water or aqueous phase is continuous and the discontinuous phase is the silicone resin-surfactant phase. Those skilled in the art will recognize that should it be necessary to create an emulsion where the resin is in the continuous phase, the emulsifying surfactants can be selected with relatively lower HLB values for that purpose. However for the water base coatings applications contemplated by the present invention, it is ordinarily more apropriate that the water be the continuous phase.It should be noted that once the selfemulsifiable silicone resin composition has been added to the aqueous medium and disperses therein a water based coating is produced. The aqueous medium can be water alone or it can include other ingredients desired in various coating applications.

The silicone resins which are useful ingredients in the compositions of the present invention are standard materials available from a number of silicone producers. These resins are generally the hydrolyzed products of organotrichlorosilane and diorganodichlorosilane mixtures which can also include a solvent. The hydrolysis reaction provides silanol chain-stopped low viscosity resin polymers which can then be bodied with a catalyst by well known means to build the molecular weight and viscosity of the resin to a desired end-point and provide resins having suitable properties in water-based coatings applications.

For example, a silane blend composed of methyltrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane and diphenyldichlorosilane can be hydrolyzed in a mixture of acetone and water. Following the complete addition of the silane blend the mixture is agitated for a period of time (such as a half hour) whereupon the mixture is allowed to settle for approximately an hour.

The resin layer will ordinarily settle to the bottom and can be drawn off whereupon the top layer can be discarded. Those skilled in the art will recognize that the density of the resin phase can be influenced by several factors, as for example the phenyl concentration, such that it is sometimes possible that the resin layer will remain on top and the lower layer is then discarded.

Additional water is added to the resin layer and the mixture is heated whereupon the water and residual acetone is stripped off at atmospheric pressure to 1 60 C. All of the water is not removed during this step since the water can act as a resin bodying catalyst during the stripping process. The resin is then cooled to below 90"C and VM a P Naphtha, acetone, and water is added for a final acid reduction of the mixture. The mixture is then heated to reflux and the acetone and water is stripped off to 150"C. The acid reduction step is repeated until the acidity is reduced to a desirable low acidity level in order to provide stable resins, as is well known in the art. The resin is then filtered through Celite and Fuller's Earth.This process produces a resin at approximately 90% silicone solids. The solids level can be adjusted with additional VM 8 P Naphtha as necessary.

Another silicone resin which is acceptable for use in the self-emulsifiable resin compositions of the present invention can be made in the following manner. One hundred parts of organohalosilanes can be placed in a hydroysis vessel. This mixtures of silanes could contain various molar percentages of, for example, the following silanes: methylytrichlorosilane, phenyltrichlorosilane, dimethyldichlorosilane, and diphenyldichlorosilane. This silane blend can be added with agitation to a mixture of approximately 90 parts of toluene, 40 parts acetone, and 300 parts water, while maintaining good agitation.The addition time could be controlled such that the reacting mixture which starts at approximately room temperature will peak at a temperature of approximately 70"C. Following complete addition of the silane blend to the mixture in a hydrolyzer, the mixture is further agitated for a half hour. In this case the lower phase contains predominately acid water which is drawn off from the hydrolyer and discarded. Additional water can be added to the mixture with agitation for a few minutes. Approximately 10% of fresh water based upon the resin solid content is sufficient for this step. After the mixture has been allowed to settle, excess water can be drawn off the bottom layer and discarded. Next, the solvent is stripped of the remaining solution at 1 20 C and the resin concentrate can thereupon be tested for acidity.An acid reduction step can be accomplished by cooling the batch and repeating the 10 percent water wash step if necessary. Next, the resin mixture is heated to reflux and the remaining water if any is trapped off. Next the silicone resin is bodied by any of several well known means in order to achieve a silicone resin having the desired final molecular weight. For example, a number of metal soaps are effective resin bodying catalysts. Included in this group would be the soaps of zinc, tin, manganese, cobalt, or iron, for example. Specific examples of a bodying catalyst would include zinc octoate and stannous octoate. Catalytic amounts of the bodying catalyst can be charged to the washed resin and the solvent is stripped to 140"C total reflux during the bodying process.After a particular desired bodying end point has been reached, the resinous product is cooled and cut with a solvent to achieve the final desired solids level.

Silicone resins made by the above described processes or analogous processes can become part of a self-emulsifiable system when used in conjuction with certain soluble emulsifiers which will be described below. Blends of silicone resins and various soluble nonionic, cationic and anionic emulsifiers can form self-emulsifiable transparent solutions which are found to be readily dispersible or self-emulsifiable when added to water and gently stirred or shaken. It is unnecessary to supply external mechanical energy to these compositions (as for example by colloid milling) in order to produce emulsions of these materials.

Among the emulsifiers found to be useful in the self-emulsifying resin blends of the present invention are the following which are listed by type: Non-ionic Emulsifiers polyoxyethylene 20 sorbitan monolaurate (i.e. polysorbate 20) polyoxyethylene 20 sorbitan monooleate (i.e. polysorbate 80) polyoxyethylene 20 sorbitan monostearate polyoxyethylene glycol 40 stearate polyoxyethylene glycol 400 monooleate alkyl aryl polyethoxy (3 to 50) ethanols e.g. octylphenoxypolyoxy ethylene glycol having a formula (C8H17C6H4) (OCH2CH2)nOH where n = 1 to 100. This composition has a C.A.S. Registry No. 9036-19-5.

Another example is nonylphenoxypolyoxy ethylene glycol having a formula C9H19C6H4O(CH2CH2O) x-CH2CH2OH where x = 0 to 100 and has C.A.S. Registry No. 26027-38-3.

polyoxyethylene 5 oleamide polyoxyethylene 10 cetyl ether polyoxyethylene 10 oleyi ether alkyl polyethylene glycol ether e.g. trimethylnonylether of polyoxyethyleneglycol having a formula (QH4O)C1 2H260 where n = 1 to 100 (preferably 3 to 10) and has C.A.S. Registry No. 9002-92-0.

Cationic Emulsifiers dimethyl dicocoammonium chloride polyoxyethylene 5 tallowamine Anionic Emulsifiers phosphated cetyl ether amine salts of dodecylbenzene sulfonic acid Each of the various listed emulsifiers were found to be soluble at a 17% level in silicone resins produced by the above discussed methods. Furthermore it has been found that the resulting emulsifier-resin solutions are self-emulsifiable when dispersed in water and most of these have been found to be non-hazy at - 1 5'C.

EXAMPLE 1 A silicone resin was prepared in the following manner. One hundred parts by weight of a silane blend comprised of 10 mole percent methyltrichlorosilane, 20 mole percent phenyltrichlorosilane, 40 mole percent dimethyldichlorosilane, and 30 mole percent diphenyldichlorosilane was charged to a hydrolyzer along with 100 parts acetone and 300 parts water. The silane blend was added at a controlled feed rate over a 60 minute addition period. The temperature of the reaction blend reached 65"C at which temperature the reaction was maintained. Agitation was continued for approximately 30 minutes upon completion of the addition of the silane blend. Next the batch was allowed to settle for approximately one hour whereupon the lower resin layer was separated and removed to a wash tank and the upper acid/water layer was disposed.Next, 6.6 parts of water were charged to the resin hydrolyzate. The water and residual acetone was then stripped off at atmospheric pressure and 1 60 C. It is to be noted that all of the water does not come off during this step and it is critical that the temperature be maintained at 1 60 C. Once this temperature had been maintained, cooling was initiated. After the resin hydrolyzate had been cooled to less than 90"C, approximately seven parts of VM 8 P Naphtha, 6.6 parts of water and 6.6 parts of acetone were added to the hydrolyzate. This mixture was heated to reflux and the water and acetone was trapped off at 1 50 C. Refluxing was continued until substantially all of the water had been removed.At this point the acidity was reduced with additional water and the reflux step was repeated. Then the reduced resin was filtered through Celite 545 and Fuller's Earth. This step was also repeated. Additional VM 8 P Naphtha was added until the resin was at approximately 86 percent silicone solids level. The resin provided by this process will hereinafter be referred to as resin A. A self-emulsifiable resin of the present invention was thereupon provided by blending 20.8 parts of resin A with 1.11 parts of nonylphenoxy poly (ethylene oxy) (3) ethanol and 1.63 parts of nonylphenoxy poly (ethylene oxy) (19) ethanol. These emulsifiers were completely soluble when blended with the resins and formed a transparent system. When the soluble blend of emulsifier and resin was added to water, it dispersed readily and remained dispersed with only slight aqueous separation for a period in excess of three weeks. Additionally, any slight aqueous separation can be minimized with mild shaking which readily disperses the system again. Thus self-emulsifiable resins were provided which did not require the use of colloid milling.

EXAMPLE 2 Another silicone resin was prepared in the following manner. Forty parts of acetone, 90 parts of toluene, and 300 parts of water were charged to a hydrolyer and the mixture was cooled to approximately 20 to 25"C. To this mixture was then added a silane blend comprising approximately 24 parts by weight methyltrichlorosilane, 34 parts phenyltrichlorosilane, 14 parts dimethyldichlorosilane, and 28 parts diphenyldichlorosilane. The silane blend was added with a controlled feed rate over a period of approximately 40 minutes so that the reaction temperature did not exceed approximately 70"C. After the silane blend had been completely added to the hydrolyzer, agitation was continued for approximately 30 minutes to ensure complete hydrolysis of the silanes.Agitation was discontinued and the lower acid layer phase was drawn off and discarded. Next, approximately 8 parts of fresh water was added to the resin hydrolyzate. This mixture was agitated for an additional 5 minutes whereupon it was allowed to settle for approximately a half hour. Again the bottom water layer was separated and discarded. Next the resin hydrolyzate was atmospherically stripped of its solvents at temperatures up to 1 20 C. The hydrolyzate was then heated to reflux to trap off the remaining water. Next 2/10 of a part of an 8% solution of zinc octoate in toluene was added to the batch for bodying. The solvent was stripped off to 1 40 C total reflux.Bodying was continued until aZahn Cup end point indicated that the desired viscosity was approximately 1 50 centipoise at the 50 percent solids level. When the bodying end point was reached the batch was immediately cooled and cut with approximately with 4 parts of toluene. The remaining bodies resin was then filtered through Celite and Fuller's Earth and adjusted to provide a 50% silicone solids solution in toluene. The resin provided by this process will hereinafter be refered to as resin B. A self-emulsifiable resin of the present invention was then provided by blending 1 600 grams of resin B with 1 60 grams of Surfonic N-40. To this blend was then dispersed 240 grams of Igepal CO-850 solid at 40"C.

It was found that these emulsifiers were completely soluble when blended in the resin system and were found effective for readily dispersing the silicone resin when added to water thus forming the self-emulsifiable silicone resin system. This particular self-emulsifiable silicone resin composition froze solid at refrigeration of - 1 5'C but did not experience phase separation.

By way of comparison, 21 grams of resin B was combined with .65 grams of Pluronic 1 7R2 and 1.09 grams Pluronic 1 7R4. It was found that both of these emulsifiers were sufficiently soluble in resin B however this composition was not found to be self-emulsifiable in accordance with the process of the present invention.

EXAMPLE 3 Two grams of each of the following listed emulsifiers or blends were added to 10 grams of the silicone resin A produced in Example 1. For those emulsifiers which were found to be soluble in the resin, a 1 gram blend of the emulsifier-resin mixture was further blended with 4 grams of water and tested for self-emulsifiability. Table 1 lists the various emulsifying agents and whether they were each soluble in the resin. The column labled Dispersible refers to the characteristic of the emulsifier-resin system to be self-emulsifiable in water upon moderate agitation or shaking without the necessity of additional energy input. Appearance of the emulsions at both - 1 5'C and 20"C are listed as OK if the emulsions were substantially clear (i.e. no haze) at those temperatures.

TABLE I Emulsifiers Solubility Dispersibility - 75"C 20 "C Surfonic N-40 (1gum) Soluble Dispersible OK OK + 1gum Witconol NP-200 Ethosperse SL-20 Haze - - - Glycosperse 0-20 Soluble Dispersible OK OK Ethomid 0/15 Soluble Dispersible OK Ethomeen T-15 Soluble Dispersible OK Glycosperse S-20 Soluble Dispersible OK OK Witconate P-1059 Soluble Dispersible OK OK Brij 56 Soluble Dispersible Haze OK Brij 96 Soluble Dispersible Haze OK Witconol H31A Soluble Dispersible OK Arquad 2C-75 Soluble Dispersible Haze OK Crodafos SG PP65 Soluble Dispersible OK Arlacel 20 Haze - - - Witconol NP-300 (1gum) Soluble Dispersible - OK + 1 gm Surfonic N-40 Tween 85 Haze - - Surfonic N-40 Soluble Poorly - Dispersible "These emulsions experienced rapid phase separation but redispersed with additional agitation.

EXAMPLE 4 The utility of the present invention can be further demonstrated as follows. Fifty parts by weight of low molcular weight dimethylpolysiloxane silicone oil having a viscosity of 10 centipoise at 25"C was combined with 75 parts by weight of toluene and dissolved therein. To this solution was added 10 parts by weight of the surface active agent consisting of a blend of alkylphenols manufactured under the brand name Triton X 1 00. When this mixture was added to water it readily dispersed throughout with only moderate mixing and without the need for a colloid mill. This demonstrates that the self-emulsifying process of the present invention is not limited to classic silicone resins but can also be utilized with relatively linear, low molecular weight silicone dimethylfluids which are also useful in coating applications.

Claims (26)

1. A self-emulsifiable solicone resin composition comprising: a) 100 parts by weight of an organosilicon compound which is an organopolysiloxane polymer having 0.8 to 2.5 organic groups per silicon atom and which is comprised of units selected from RSiO, 5, R2SiO, R3SiOo5, and Six2, wherein R represents hydrogen or a monovalent hydrocarbon radical having from one to twenty carbon atoms; and b) 1 to 50 parts by weight of a surface active agent or blends of such agents which is completely soluble in said organosilicon compound and is effective for dispersing said organosilicon compound in an aqueous medium upon introduction of said self-emulsifiable silicone resin composition therein.

2. A composition as claimed in claim 1 wherein said organosilicon compound is in a hydrocarbon solvent solution.

3. A composition as claimed in claim 1 or claim 2 wherein said organosilicon compound comprises 30 to 95 percent by weight of said solution and has a viscosity of 10 to 10,000 centipoise at 25"C.

4. A composition as claimed in any one of the preceding claims wherein said organosilicon compound is selected from 0 to 100 mole percent CH3SiOa 5 units, 0 to 60 mole percent C6H5SiO1 5 units, 0 to 50 mole percent (CH3)2SiO units, 0 to 50 mole percent (C6H5)2SiO units, O to 70 mole percent SiO units, and 0 to 70 mole percent R2R'SiOo5 units wherein R is as defined in claim 1 and R' is the same as R or hydogen, or a phenyl or vinyl radical.

5. A composition as claimed in any one of the preceding claims wherein said surface active agent is selected from non-ionic polyethoxylated esters and ethers, cationic dimethyl dicocoammonium chloride and polyoxyethylene 5 tallowamine, and anionic phosphated cetyl ethers, or amine salts of dodecylbenzene sulfonic acid.

6. A composition as claimed in claim 5 wherein said non-ionic polyethoxylated esters and ethers are selected from polyoxyethylene 20 sorbitan monolaurate, polyoxyethylene 20 sorbitan monooleate, polyoxyethylene 20 sorbitan monostearate, polyoxyethylene glycol 40 stearate, polyoxyethylene glycol 400 monooleate, alkyl aryl polyethoxy (3 to 50) ethanols, polyoxyethylene 5 oleamide, polyoxyethylene 10 cetyl ether, polyoxyethylene 10 oleyl ether, and alkyl polyethylene glycol ether.

7. A composition as claimed in any one of the preceding claims wherein said surface active agent or blends of such agents had an HLB value which is greater than 8 and is effective for providing an emulsion having a continuous aqueous phase.

8. A process for providing a self-emulsifiable silicone resin composition comprising the steps of mixing: a) 100 parts by weight of an organosilicon compound which is an organopolysiloxane polymer having 0.8 to 2.5 prganic groups per silicon atom and which is comprised of units selected from RSiO, 5, R2SiO, R3SiOo5, and SiO2, wherein R represents hydrogen or a monovalent hydrocarbon radical having from one to twenty carbon atoms; and b) 1 to 50 parts by weight of a surface active agent or blends of such agents which is completely soluble in said organosilicon compound and is effective for dispersing said organosilicon compound in an aqueous medium upon introduction of said self-emulsifiable silicone resin composition therein.

9. A process as claimed in claim 8 wherein said organosilicon compound is in- a hydrocarbon solvent solution.

10. A process as claimed in claim 8 or claim 9 wherein said organosilicon compound comprises 30 to 95 percent by weight of said solution and has a viscosity of 10 to 10,000 centipoise at 25"C.

11. A process as claimed in any one of claims 8 to 10 wherein said organosilicon compound is selected from 0 to 100 mole percent CH3SiO, 5 units, 0 to 60 mole percent C6G5SiO,5 units, O to 50 mole percent (CH3)2SiO units, 0 to 50 mole percent (C6H5)2SiO units, O to 70 mole percent SiO2 units, and 0 to 70 mole percent R2R'SiOo5 units wherein R is as defined in claim 1 and R' is the same as R or hydrogen, or a phenyl or vinyl radical.

1 2. A process as claimed in any one of claims 8 to 11 wherein said surface active agent is selected from non-ionic polyethoxylated esters and ethers, cationic dimethyl dicocoammonium chloride and polyoxyethylene 5 tallowamine, and anionic phosphated cetyl ethers, or amine salts or dodecylbenzene sulfonic acid.

1 3. A process as claimed in claim 1 2 wherein said non-ionic polyethoxylated esters and ethers are selected from polyoxyethylene 20 sorbitan monolaurate, polyoxyethylene 20 sorbitan monooleate, polyoxyethylene 20 sorbitan monostearate, polyoxyethylene glycol 40 stearate, polyoxyethylene glycol 400 monooleate, alkyl aryl polyethoxy (3 to 50) ethanols, polyoxyethylene 5 oleamide, polyoxyethylene 10 cetyl ether, polyoxyethylene 10 oleyl ether, and alkyl polyethylene glycol ether.

1 4. A process as claimed in any one of claims 8 to 1 3 wherein said surface active agent or blends of such agents has an HLB value which is greater than 8 and is effective for providing an emulsion having a continuous aqueous phase.

1 5. A water-based coating compositing comprising A) 100 parts by weight of a water-based coating bath; and B) 1 to 500 parts by weight of a self-emulsifiable silicone resin composition comprising: a) 100 parts by weight of an organosilicon compound which is an organopolysilicon compound which is an organopolysiloxane polymer having 0.8 to 2.5 organic groups per silicon atom and comprising units selected from Rio,5, R2SiO, R3SiOo 5, and SiO2, wherein R represents hydrogen or a monovalent hydrocarbon radical having from one to twenty carbon atoms; and b) 1 to 50 parts by weight of a surface active agent or blends of such agents which is completely soluble in said organosilicon compound and is effective for dispersing said organosilicon compound in an aqueous medium upon introduction of said self-emulsifiable silicone resin composition therein.

16. A composition as claimed in claim 1 5 wherein said organosilicon compound is in a hydrocarbon solvent solution.

1 7. A composition as claimed in claim 1 6 wherein said organosilicon compound comprises 30 to 95 percent by weight of said solution and has a viscosity of 10 to 10,000 centipoise at 25"C.

18. A composition as claimed in any one of claims 1 5 to 1 7 wherein said organosilicon compound comprises 0 to 100 mole percent CH3H5SiO, 5 units, 0 to 60 mole percent C6H5SiO, 5 units, 0 to 50 mole percent (CH3)2SiO units, 0 to 50 mole percent (C5H5SiO units, 0 to 70 mole percent SiO2 units, or O to 70 mole percent R2R'SiOo5 units wherein R is as defined in claim 1 and R' is the same as R or hydrogen, or a phenyl or vinyl radical.

1 9. A composition as claimed in any one of claims 1 5 to 1 8 wherein said surface active agent is selected from non-ionic polyethoxylated esters and ethers, cationic dimethyl dicocoammonium chloride and polyoxyethylene 5 tallowamine, and anionic phosphated cetyl ethers, or amine salts of dodecylbenzene sulfonic acid.

20. A composition as claimed in claim 1 9 wherein said non-ionic polyethoxylated esters and ethers are selected from polyoxyethylene 20 sorbitan monolaurate, polyoxyethylene 20 sorbitan monooleate, polyoxyethylene 20 sorbitan monostearate, polyoxyethylene glycol 40 stearate, polyoxyethylene glycol 400 monooleate, alkyl aryl polyethoxy (3 to 50) ethanols, polyoxyethylene 5 oleamide, polyoxyethylene 10 cetyl ether, polyoxyethylene 10 oleyl ether, and alkyl polyethylene glycol ether.

21. A composition as claimed in any one of claims 1 5 to 20 wherein said surface active agent or blends of such agents has an HLB value which is greater than 8 and is effective for providing an emulsion having a continuous aqueous phase.

22. A composition as claimed in any one of claims 1 5 to 21 wherein said water-based coating bath is water.

23. A process as claimed in any one of claims 8 to 1 4 further comprising the step of mixing 100 parts by weight of a water-based coating bath with 1 to 500 parts by weight of said selfemulsifiable silicone resin composition.

24. A composition as claimed in claim 1 substantially as hereinbefore described in any one of the Examples.

25. A process as claimd in claim 8 substantially as hereinbefore described in any one of the Examples.

26. A composition when produced by a process as claimed in any one of claims 8 to 14, 23 or 25.