Process for producing epoxyorganosilicon compounds

Abstract

The present invention describes a method for producing epoxyorganosilicon compounds through the platinum-catalyzed hydrosilation reaction of ethylenically unsaturated epoxides and a silicon-hydride in the presence of a carboxylic acid salt. Also taught herein is the use of carboxylic acid salts in compositions of epoxyorganosilicon compounds to provide compositions of greater stability.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of application Ser. No. 09/573,111, filed May 17, 2000, which is a continuation-in-part of application Ser. No. 09/465,603, filed Dec. 17, 1999, now abandoned.

BACKGROUND OF THE INVENTION

[0002] In the production of silicon compositions, transition metal catalysts have long been known to promote the hydrosilation reaction. In addition to catalyzing the hydrosilation reaction, many transition metals, in the presence of silicon hydrides (Si—H), also promote epoxide ring-opening polymerization of the ethylenically unsaturated epoxide starting material and the epoxysilane or epoxysilicone product of the hydrosilation reaction. This epoxide ring-opening polymerization reaction during production of an epoxysilane or epoxysilicone can lead to gelation, and may result in both the loss of the entire batch and in considerable loss of time to remove the insoluble gelled resin. Additionally, a partial gelation can occur during epoxysilicone synthesis such that reproducible batch-to-batch viscosities of the epoxysilicone product may be difficult to obtain.

[0003] In the presence of precious metal hydrosilation catalysts, epoxysilicones have been found to gel slowly on storage at room temperature due to the epoxide ring-opening polymerization, thus shortening the shelf life of the epoxysilicone product. This storage problem can be partially alleviated by deactivating the transition metal catalyst with a catalytic inhibitor as reported in U.S. Pat. No. 4,083,856 (F. Mendicino), which discloses the use of diphenylamine to inhibit gelation. Overall, it would be less preferable to incorporate an extra component or an additional process step into the epoxysilicon composition and production process.

[0004] The prior art has taught that the epoxide ring-opening polymerization side reaction does not occur in the rhodium-catalyzed hydrosilation reaction of an ethylenically unsaturated epoxide and a Si—H. For example, U.S. Pat. Nos. 5,442,026 (Crivello et al.), 5,169,962 (Crivello et al.), 4,804,768 (Quirk et al.) teach that rhodium catalysts such as Wilkinson's catalyst, RhCl3 hydrate, RhH(CO)(PPh3)3 can be used to produce epoxy silicones. In addition to rhodium catalysts, certain platinum catalyst systems have been reported to selectively catalyze the hydrosilation reaction of ethylenically unsaturated epoxides and a Si—H versus the epoxide ring-opening polymerization side reaction, as disclosed in U.S. Pat. No. 5,583,194 (Crivello et al.) which teaches that quaternary onium hexachloroplatinate salts, e.g., (R4M)2PtCl6, or as disclosed U.S. Pat. No. 5,260,399 (Crivello et al.) transition metal phosphine complexes, e.g., Pt(PPh3)4, can be used to produce epoxysilicon compositions. However, these catalysts have not achieved commercial acceptance yet.

[0005] U.S. Pat. Nos. 5,240,971, 5,227,420, and 5,258,480 (Eckberg et al.) reported the preparation of epoxysilicones using either RhCl3[S(n-Bu)2]3 or PtCl2(SEt2)2 as the catalyst in the presence of a tertiary amine to control the viscosity during the hydrosilation reaction. However, only a limited number of transition metal catalysts are active in the presence of this stabilizer.

[0006] Carboxylic acids have been reported to promote the transition metal catalyzed hydrosilation reaction, as disclosed in JP 11 180,986 (M. Tachhikawa; K. Takei), F. Mendicino; C. Schilling Jr. Abstract of Papers, 32nd Organosilicon Symposium; 1999; P-68, and in UDC 415,268 (Belyakova et al.). But, carboxylic acid salts have not. Carboxylic acid salts have been reported to prevent acetal formation through the hydroxyl groups of a silicone polyether copolymer as disclosed in U.S. Pat. No. 4,847,398 (K. R. Mehta et al.); however, no utility for epoxides is disclosed.

[0007] The literature does mention that alcohols prevent or retard the epoxide ring-opening polymerization reaction (A. K. McMullen; et al. Abstract of Papers, 27th Organosilicon Symposium, 1994; Abstract P-45; and Crivello et al. Polym. Preps. 1991, 32, 338).

[0008] It is apparent that there exists a need in the industry for a method to eliminate epoxide ring-opening polymerization, and olefin isomerization when commonly used hydrosilation catalysts, such chloroplatinic acid, are employed. There is also a need for an efficient yet economical method of producing epoxysilicone monomers and oligomers in the absence of the epoxide ring-opening polymerization reaction, thereby generating epoxysilicon compositions of reproducible batch-to-batch viscosity. There is additionally a need for epoxysilicon compositions that are stable to the epoxide ring-opening polymerization reaction and therefore have increased the shelf life without an additional processing step.

SUMMARY OF INVENTION

[0009] The object of this invention is to provide a method for preparing epoxy organosilicon compositions through the platinum metal-catalyzed hydrosilation reaction between an ethylenically unsaturated epoxide and a hydrido organosilicon in the presence of a carboxylic acid salt where the catalyst efficiently promotes the hydrosilation reaction without also promoting either the epoxide ring-opening polymerization reaction of either the ethylenically unsaturated epoxide starting material, the epoxysilicon composition or the isomerization of the ethylenically unsaturated epoxide starting material. Compositions of epoxy organosilicon compounds and the salt of the carboxylic acid are taught as well wherein the salt suppresses the reactivity of the epoxy functionality.

DETAILED DESCRIPTION OF THE INVENTION

[0010] According to the process of the invention, the platinum-catalyzed hydrosilation of an ethylenically unsaturated epoxide with either a hydrido silane or hydrido siloxane occurs in the presence of a carboxylic acid salt without epoxide ring-opening polymerization side reaction, allowing for the production of high yields of epoxyorgano silanes or siloxanes. For certain carboxylic acid salts, both epoxide ring-opening polymerization and olefin isomerization are suppressed. This inventive process allows for greater batch-to-batch consistencies without the use of more complex catalyst systems. While the process is useful for both siloxanes and silanes, given that the internal rearrangement of the olefin is more of an issue in the hydrosilation of a silane, the present invention will find greater utility in the hydrosilation of hydrido alkoxysilanes.

[0011] These salts are also useful for the suppression of the reactivity of the epoxide after the hydrosilation reaction and thus are useful to extend the shelf life of epoxy organosilicon materials, even if post added after hydrosilation.

[0012] Ethylenically unsaturated epoxides for use herein include linear or cycloaliphatic epoxy compounds wherein the unsaturation is terminal (i.e.,±, 2) which contain from 4 to 50 carbon atoms. The epoxide may be visualized as an ethylenically unsaturated epoxide of the formula: 1

[0013] where R can be a single bond or an alkylene optionally containing alkyl pendant groups; R1, R2 and R3 can individually be hydrogen, alkyl straight, branched or cyclic, or any two of R1, R2 or R3 can be alkylene and combined to form a 5 to 12 carbon cyclic ring, optionally containing alkyl pendants; and the number of carbon atoms in R, R1, R2, and R3 are such that the total number of carbon atoms in the epoxide is from 4 to 50. Some representative epoxides are: 4vinylcyclohexene monoxide, 1-methyl-4-isopropenyl cyclohexene monoxide, and butadiene monoxide. The preferred epoxide is 4-vinylcyclohexene monoxide.

[0014] The hydridosilanes may be alkoxy silanes. The hydrido alkoxysilanes that may be used include the trialkoxysilanes, such as trimethoxysilane, triethoxysilane, tri-n-propoxysilane, and triisopropoxysilane. Trimethoxysilane and triethoxysilane are preferred. Other hydroalkoxysilanes include dialkoxysilanes such as methyldimethoxysilane, methyldiethoxysilane, dimethylmethoxysilane, and dimethylethoxysilane. Hydrosilanes in general can be represented by the formula R4,(OR4)3−nSiH, wherein R4 is a branched or linear alkyl group of 1 to 18 carbon atoms, a cyclic alkyl group of four to eight carbon atoms or an aryl, alkaryl, an aralkyl group of six to twelve carbon atoms, optionally containing halogen, oxygen, or nitrogen substituents with the proviso that such substituents do not interfere with either hydrosilation or promotion, and n is an integer selected from 0, 1, and 2. R4 is preferably a C1-C2 alkyl wherein n is preferably 1 or 0.

[0015] The hydrido organosiloxanes have the general formula:

[R5a(H)bSiO(4−a−b)/2]n

[0016] wherein R5 represents a monovalent hydrocarbon radical, a has a value of from 1 to 2.99, b has a value of from 0.001 to 1, and the sum of a+b has a value of from 1.5 to 3.0 and n=2 to 400. More specifically, examples of the silicone hydride are heptamethyltrisiloxane (MD′M), tetramethyldisiloxane (M′M′), cyclic siloxanes DjD′k, and linear siloxanes MDxD′yM, wherein M=—O½Si(CH3)3, M′=—O½Si(H)(CH3)2, D′=—OSi(H)(CH3)2-, D=—OSi(CH3)2-, j=1 to 8, k≧1 and j+k=4 to 8, x=0 to 200 and y=1 to 200. Preferably j+k=4 to 5, x=1 to 20 and y=1 to 50.

[0017] The salt of the carboxylic acid may be represented by the formula R6CO2M wherein M represents an alkali, alkaline earth, transition metal, or an ammonium ion and R6 represents a monovalent hydrocarbon of one to 18 carbon atoms, which may be substituted with amino groups, hydroxyl functionalities, carboxyl groups or ester groups. Preferably R6 is a linear or branched alkyl of one to ten carbons or an aryl or alkaryl of 6 to 12 carbons. Specific examples of carboxylic acid salts include one or more salts of the alkali metals, e.g., lithium acetate, sodium acetate, potassium acetate, potassium benzoate, sodium trifluoroacetate or sodium propionate, of the alkaline earth metals, e.g., calcium acetate, of the transition metals, e.g., samarium (III) acetate, copper (II) acetate, copper (II) ethylhexanoate, indium (III) acetate, and nonquatemary ammonium or phosphonium, e.g., ammonium formate, ammonium acetate, ammonium isovalerate, ammonium 2ethylbutyrate, ammonium propionate or combinations of salts such as ammonium chloride and sodium acetate are suitable with this process, with ammonium salts of carboxylic acids being preferred, and ammonium propionate being the most preferred carboxylate salt. The acid may be a hydroxy acid, but only when the organosilicon hydride is an organosiloxane. The acid may be an amino acid, e.g., lysine or glutamic acid, but said acids are not preferred since they do not reduce olefin isomerization. Polymeric acids, such as polyacrylic acid may be used, in which case some of the acid may be left in acid form, i.e., it does not have to be neutralized to the salt form.

[0018] In the method of this invention, the present carboxylic acid salts are most useful in the range of 1 to about 10000 parts per million (ppm), preferably in the range of 200 to about 5000 ppm, and most preferably in the range of 100 to about 500 ppm based upon the weight of the ethylenically unsaturated epoxide.

[0019] The platinum catalyst can be of any form of platinum, which catalyzes the hydrosilation reaction of an ethylenically unsaturated epoxide and a silicon hydride. Platinum catalysts useful in the process of the invention include: hexachloroplatinic acid, various solutions derived from chloroplatinic acid, tris(tetramethyldivinyldisiloxane)diplatinum (0), phosphine complexes of platinum, and bis(acetylacetonate)platinum (II). The preferred catalyst in the practice of this invention is derived from a solution of hexachloroplatinic acid, where the most preferable catalyst is derived from a 10% (wt/wt) solution of hexachloroplatinic acid in ethanol. In the method of this invention, said catalysts are most useful in the range of 1 to about 5000 parts per million (ppm), preferably in the range of 1-500 ppm, and most preferred in the range of 5-50 ppm of platinum, based upon the weight of the combined weight of both the ethylenically unsaturated epoxide and SiH containing reactant.

[0020] This reaction can be carried out over a wide range of temperatures and pressures; however, the usual temperature range is from 50° C. to about 175° C. with the preferred temperature range being from about 75° C. to 125° C. The preferred pressure is atmospheric pressure. The duration of the reaction will be dependent on catalyst concentration and the reaction temperature. At higher catalyst concentrations and temperatures, the reaction will require less reaction time. The residence time within the reactor is not critical but should be sufficient to achieve a satisfactory degree of conversion to the hydrosilated product, i.e., >80%, within acceptable limits given the volume of the equipment and the desired rate of production. Typical acceptable residence times are on the order of 0.5 to 4 hours. The reaction is usually conducted with no solvent, although a solvent may be used. Any hydrocarbon may be used such as octane, toluene or xylene.

[0021] This reaction can be conducted in the presence of excess olefin or silicon hydride, where the preferred reaction conditions are with a molar excess of olefin. The usual substrate concentration for conducting the reaction is either a 1.5:1.0 to a 1.0:1.5 molar ratio of olefin to silicon hydride (based on moles of hydrogen), preferably a ratio of 1.0:1.0 to 1.5:1.0 and preferred conditions are a 1.01:1.0 to 1.20:1.0 molar ratio of olefin to silicon hydride. The preferred catalyst system can be generated by mixing the catalyst and carboxylic acid salt in the olefin or the carboxylic acid salt can be added to the silicon composition after the hydrosilation reaction is complete. A catalyst promoter such as a carboxylic acid or an alcohol may be used with the carboyxlic acid salt, if necessary.

[0022] The resulting product may be purified for use, e.g., by stripping or distillation, as required.

[0023] The hydrosilation may be conducted batchwise, semi-batchwise or continuously as is known in the art.

EXAMPLES

[0024] The following illustrative and comparative examples are intended to describe the present invention in more detail; however, they are not meant to limit the scope of the specification and claims. All parts and percentages presented in the examples below are by weight unless otherwise specified. The abbreviations g, mL, VCMX, CPA, Si—H, AcOH, MeOH, EtOH, IPA, cSt and GC stand for, respectively, gram, milliliter, 4-vinylcyclohexene monoxide, solution consisting of 10% (wt/wt) of hexachloroplatinic acid in ethanol, any silicon hydride-containing species, acetic acid, methanol, ethanol, isopropanol, centistokes and gas chromatography. An internal standard was used in order to determine the percent of uneluted heavies for each GC analysis. Uneluted heavies are defined as all components that did not elute under the GC conditions employed for the specific analysis. An * indicates no internal standard was used.

Comparative Examples

[0025] For Example 1—at room temperature, 21.98 g of neat VCMX was treated with 0.018 ml of CPA and warmed. At 90° C., the VCMX solution was reacted with 20.46 g of (MeO)3SiH. After the (MeO)3SiH addition was completed, the solution was maintained at 90° C. After 30 minutes, a vigorous exothermic reaction occurred accompanied with an increase in viscosity of the solution and eventual solidification (or gelation).

Examples 2-15

[0026] All reactions were conducted using a 10% molar excess of VCMX (97% purity) versus (MeO)3SiH and the specified catalyst system at 90° C. followed by one hour at 90° C. after the addition was completed. All solutions were analyzed using gas chromatography.

Example 2

[0027] At room temperature, 19.18 g of neat VCMX was treated with 0.005 g of Pt(PPh3)4, 0.040 ml of MeOH, and 0.040 ml of AcOH and warmed. At 90° C., the VCMX solution was reacted with 17.10 g of (MeO)3SiH. After the (MeO)3SiH addition was completed, the solution was maintained at 90° C. for one hour. The results are in the table below with other comparative experiments run under similar conditions. 1 TABLE 1 Comparative examples for the transition metal-catalyzed hydrosilation reaction of VCMX and (MeO)3SiH. VCMX uneluted Examples Catalyst Systema (MeO)3SiH (MeO)4Si VCMX isomer product heavies 2 Pt(PPh3)4 (10 ppm Pt) 0.2 1.4 <0.1 2.5 90.5 2.2 3 RhCl3 hydrate (50 ppm Rh) and 250 1.7 16.6 2.3 33.1 34.3 5.6 ppm tetrabutylammonium bromide 4 K2PtCl6 (50 ppm Pt) and 250 ppm 1.8 17.2 55.6 16.1 4.3 * tetrabutylammonium chloride 5 CPA (10 ppm Pt) and 250 ppm 0.5 1.1 0.3 5.9 47.2 42.9 tetramethylammonium chloride 6 CPA (10 ppm Pt) and 250 ppm 2.2 30.0 28.6 14.6 8.8 9.3 tetraethylammonium chloride 7 CPA (10 ppm Pt) and 116 ppm 6.2 25.4 23.6 16.6 18.0 5.0 tetrabutylammonium chloride 8 CPA (10 ppm Pt) and 180 ppm 16.8 3.26 2.6 10.3 1.1 * benzyltributylammonium chloride 8 RhCl3 hydrate (258 ppm Rh) and 500 <0.1 4.9 2.0 1.2 69.3 8.0 ppm triphenylphosphine 9 RhCl3 hydrate (107 ppm Rh) <0.1 1.3 0.8 4.0 86.4 3.9 10  RhCl3[S(n-Butyl)2]3 (48 ppm Rh) <0.1 1.0 3.4 3.8 88.0 1.0 11  RhCl3[S(n-Butyl)2]3 (26 ppm Rh) <0.1 1.1 5.8 1.9 86.3 1.7 12  RhCl3[S(n-Butyl)2]3 (8 ppm Rh) 16.3 1.37 4.4 1.8 3.3 * 13  Karstedts catalyst (10 ppm Pt) 0.2 1.5 0.2 4.7 57.8 31.8 aAll reactions were conducted using a 10% molar excess of VCMX (97% purity) versus (MeO)3SiH at 90° C. followed by one hour at 90° C. after the addition was completed.

Example 14

[0028] At room temperature, 19.23 g of neat VCMX was treated with 0.004 g of Pt(PPh3)4, 0.090 ml of EtOH, 0.018 ml of AcOH and warmed. At 90° C., the VCMX solution was reacted with 23.14 of (EtO)3SiH. After the (EtO)3SiH addition was completed, the solution was maintained at 90° C. for one hour. 2 Uneluted (EtO)3SiH (EtO)4Si VCMX VCMX Isomer Product Heavies 7.6 0.9 14.3 1.5 69.8 *

Example 15

[0029] At room temperature, 20.11 g of neat VCMX was treated with 0.070 ml of RhCl3[S(n-Bu)2]3, 0.023 ml of AcOH, 0.11 ml of EtOH, and warmed. At 90° C., the VCMX solution was reacted with 24.0 g of (EtO)3SiH. After the (EtO)3SiH addition was completed, the solution was maintained at 90° C. for one hour. 3 Uneluted (EtO)3SiH (EtO)4Si VCMX VCMX Isomer Product Heavies 37.2 0.4 54.6 1.3 2.9 *

EXAMPLES OF THIS INVENTION

[0030] General Procedure for the use of Carboxylate Acid Salts in the Pt-Catalyzed Hydrosilation Reaction of VCMX and a Silicone Hydride (Si—H):

[0031] 1.) where Si—H is an Organofunctional Silane

[0032] A typical reaction was conducted by treating 1.10-1.30 molar equivalents (vs. Si—H) of VCMX at room temperature with 3000 ppm of an alcohol, 500 ppm of acetic acid (AcOH), a carboxylate acid salt and a catalyst versus total mass of the reaction. Typically, 10 ppm of Pt was sufficient to catalyze the reaction. This solution was warmed. At 90° C., the solution was reacted with 1.00 molar equivalent of Si—H. The solution's temperature was maintained between 90-102° C. throughout the Si—H addition. After the Si—H addition was completed, the solutions temperature was maintained at 90° C. for one hour. After this time, solution was allowed to cool to room temperature.

[0033] 2.) where Si—H is Organfunctional Siloxane.

[0034] A typical reaction was conducted by mixing 1.10-1.30 molar equivalents (vs. Si—H) of VCMX at room temperature with an alcohol, and sodium carbonate. The VCMX solution was treated with an appropriate amount of the Si—H and the solution was warmed. At 90° C., the solution was treated with a catalyst. Typically, 10 ppm of Pt (versus the total mass of the reaction) was sufficient to catalyze the reaction. Once an initial temperature increase was detected, the remaining Si—H fluid was added to the VCMX solution. The solution's temperature was maintained between 90-100° C. throughout the Si—H addition. After the Si—H addition was completed, the carboxylic acid salt was added to the solution if it had not been added prior the hydrosilation reaction. The solution was maintained at 90° C. for one hour. After this time, solution was analyzed for Si—H content. The reaction was deemed to be complete by the absence of Si—H. The reaction mixture was warmed under reduced pressure and stripped of volatile components (primarily unreacted VCMX and the olefin isomer of VCMX) at 150° C. (75-100 mm Hg) for 2-3 hours in order to removed unreacted VCMX. The final product was then filtered through a 5¼m laboratory filter pad.

[0035] For examples 16-38, all reactions were conducted using a 10% molar excess of VCMX (97% purity) versus (MeO)3SiH, 3000 ppm methanol, 500 ppm acetic acid, carboxylic acid salt and 10 ppm Pt as a solution of chloroplatinic acid at 90° C. followed by one hour at 90° C. after the addition was completed. All solutions were analyzed using gas chromatography. 4 TABLE 2 Examples of the transition metal-catalyzed hydrosilation reaction of VCMX and (MeO)3SiH. VCMX uneluted Examples Carboxylic acid salta (MeO)3SiH (MeO)4Si VCMX isomer product heavies 16 207 ppm ammonium acetate 0.3 0.8 2.9 0.4 92.8 0.3 17 250 ppm ammonium acetate 1.2 2.8 4.9 0.4 87.6 0.4 18 125 ppm ammonium acetate <0.1 0.8 1.3 0.6 95.0 <0.1 19 100 ppm ammonium acetate <0.1 1.0 6.6 0.4 89.2 <0.1 20 50 ppm ammonium acetate <0.1 1.7 3.9 0.9 89.3 1.2 22 25 ppm ammonium acetate <0.1 0.7 9.6 0.5 85.8 0.6 23 250 ppm ammonium chloride and 0.1 0.7 11.0 0.4 84.9 0.4 250 ppm sodium acetate 24 181 ppm ammonium chloride 0.2 1.0 1.0 4.9 87.1 2.9 25 250 ppm ammonium formate 0.9 2.9 8.8 0.3 81.5 1.4 26 250 ppm ammonium propionate <0.1 0.6 0.5 0.7 96.2 <0.1 27 250 ppm ammonium isovalerate 0.1 1.1 0.5 1.2 95.0 <0.1 28 250 ppm ammonium ethylbutyrate 0.4 1.3 0.3 0.6 74.5 21.5 29 250 ppm tetramethylammonium 21.7 4.5 12.6 12.6 41.3 1.6 acetate 30 250 ppm tetrabutylammonium 13.2 8.8 29.5 6.5 28.2 7.9 acetate 31 130 ppm sodium acetate <0.1 1.4 3.4 2.5 89 1.7 32 250 ppm sodium trifluoroacetate 9.4 0.8 9.7 3.4 74.5 <0.1 33 104 ppm sodium propionate <0.1 1.0 1.6 3.7 90.2 0.3 34 99 ppm sodium propionate <0.1 2.1 1.1 8.0 83.9 1.7 35 250 ppm potassium acetate 18.2 1.4 23.0 0.8 54.1 <0.1 36 250 ppm potassium benzoate 0.9 3.0 2.8 5.0 81.6 2.5 37 500 ppm calcium acetate <0.1 0.4 4.2 2.8 80.7 10.0 38 250 ppm copper 2-ethylhexanoate 0.1 0.4 1.8 2.4 92.4 0.7 aAll reactions were conducted using a 10% molar excess of VCMX (97% purity) versus (MeO)3SiH at 90° C. followed by one hour at 90° C. after the addition was completed.

[0036] For examples 39-41, all reactions were conducted using a 10% molar excess of VCMX (97% purity) versus (MeO)3SiH, 3000 ppm methanol, 500 ppm acetic acid, specified carboxylic acid salt and the specified precatalyst at 90° C. followed by one hour at 90° C. after the addition was completed. All solutions were analyzed using gas chromatography. 5 TABLE 3 Examples for the hydrosilation reaction of VCMX and TMS in the presence of carboxylate salts with alternative Pt catalysts.a VCMX uneluted Example Catalyst System (MeO)3SiH (MeO)4Si VCMX isomer product heavies 39 (NH4)2PtCl6 (24 ppm Pt) 47.5 0.7 48.9 1.2 <0.1 <0.1 40 Pt(PPh3)4 (10 ppm Pt) and 100 ppm <0.1 1.4 14.8 1.4 76.2 3.2 sodium propionate 41 Karstedts catalyst (10 ppm Pt) and 100 1.4 1.6 <0.1 3.9 87.7 3.2 ppm sodium propionate aAll reactions were conducted in a normal addition using a 10% molar excess of VCMX (97%) and 10 ppm Pt (CPA) at 90° C. followed by a one hour at 90° C. after SiH addition was completed.

[0037] For examples 44-55, all reactions were conducted using a 20% molar excess of VCMX (97% purity) versus the specified Si—H, 3000 ppm of an alcohol, 500 ppm acetic acid, specified carboxylic acid salt and 10 ppm Pt as a solution of chloroplatinic acid at 90° C. followed by one hour at 90° C. after the addition was completed. All solutions were analyzed using gas chromatography. 6 TABLE 4 Examples of the Pt-catalyzed hydrosilation reaction of VCMX with different SiH. VCMX uneluted Examples Carboyxlic acid salta R′R2SiH R′R3Si VCMX isomer product heavies Trimethoxysilane R′=R= OMe 42 250 ppm ammonium acetate 0.2 2.1 8.2 0.3 85.4 1.0 43 307 ppm sodium propionate <0.1 3.2 2.3 7.0 82.3 1.6 Triethoxysilane R′=R OEt 44 250 ppm ammonium acetate 2.8 1.6 5.3 0.4 82.4 2.9 45 307 ppm sodium propionate 2.8 2.6 <0.1 8.7 76.0 4.8 Methyldimethoxysilane R′=CH3, R = OEt 46 250 ppm ammonium acetate <0.1 0.7 12.8 0.6 79.2 * 47 307 ppm sodium propionate 0.1 0.7 9.0 3.2 81.9 * Methyldiethoxysilane R′=CH3, R = OEt 48 250 ppm ammonium acetate 0.3 1.3 8.7 0.6 84.5 * 49 320 ppm sodium propionate 0.3 0.6 5.0 3.7 83.7 * MD′M 50 250 ppm ammonium acetate 44.0 48.7 0.1 5.7 * 51 307 ppm sodium propionate 35.0 39.8 0.2 23.4 * 52 250 ppm ammonium propionate 45.2 51.1 0.1 1.1 * M′M′ 53 250 ppm ammonium acetate, no 0.1 10.6 1.6 82.3 * acetic acid 54 307 ppm sodium propionate 0.1 16.1 1.6 76.9 * 55 250 ppm ammonium propionate 0.1 21.3 1.4 71.9 * aAll reactions were conducted in a normal addition using a 20% molar excess of VCMX (97%) and 10 ppm Pt (CPA) at 90° C. followed by a one hour at 90° C. after SiH addition was completed.

[0038] For examples 56 to 57, all reactions were conducted using a 20% molar excess of VCMX (97% purity) versus Si—H, specified carboxylic acid salt and 10 ppm Pt as a solution of chloroplatinic. At room temperature, neat VCMX was treated with a carboxylic acid salt, and CPA and was warmed. At 90° C., the VCMX solution was reacted with MD26.9D′9.4M. After the MD26.9D′9.4M addition was completed, the solution was maintained at 90° C. for one hour. The reaction mixture was warmed under reduced pressure or stripped at 150° C. (20 mm Hg) for one hour in order to removed unreacted VCMX.

[0039] For examples 58 to 60, all reactions were conducted using a 20% molar excess of VCMX (97% purity) versus Si—H and 6 ppm Pt as a solution of chloroplatinic acid. At room temperature, neat VCMX was treated with Na2CO3, propyleneglycol, tetraethyleneglycol, and MD26.9D′9.4M (10% of total Si—H), and was warmed. At 80° C., the VCMX solution was reacted with the remaining MD26.9D′9.4M. After the MD26.9D′9.4M addition was completed, the solution was maintained at 85° C. for one hour. The reaction mixture was warmed under reduced pressure and stripped at 150° C. (20 mm Hg) for one to two hours in order to removed unreacted VCMX.

Example 60

[0040] At room temperature, 196.80 g of VCMX was treated with 1.47 g of Na2CO3, 3.27 g of propyleneglycol, 0.57 g of tetraethyleneglycol, 37.09 g of MD26.9D′9.4M (10% of total Si—H) and warmed. At 80° C., 0.11 mL of CPA was added to the VCMX solution resulting in an exothermic reaction. The remaining 333.81 g of MD26.9D′9.4M was added to the VCMX solution over the course of one hour. The solution's temperature was maintained between 80-90° C. throughout the Si—H addition. After the MD26.9D′9.4M addition was completed, 1.20 g of sodium propionate was added to the crude silicone composition and the solution's temperature was maintained at 85° C. for thirty minutes. An aliquot of the solution was analyzed for Si—H content. After this time, solution was stripped at 3.5 mm Hg and 150° C. in order to removed unreacted VCMX. After 1.5 hours, the solution was allowed to cool to room temperature. Recovered 37.16 g of unreacted VCMX and its olefin isomer. The final product was then filtered through a 5 &mgr;m laboratory filter pad. 7 TABLE 5 Results from the Pt-catalyzed hydrosilation reaction of VCMX and an organohydrogensiloxane.a Ex- Carboxylic Viscosity ample acid salt [Si-H] (cSt) Epoxy content 56 250 ppm not detected  572 10.16% ammonium acetate 57 250 ppm no reaction — — tetrabutylammonium acetate 58 No sodium not detected 3021 not measured propionate used 59 No sodium not detected >10000  not measured propionate used 60 2094 ppm sodium not detected  438  9.71% propionate aAll reactions were conducted in a normal addition using a 20% molar excess of VCMX (97%) followed by one hour at 90° C. after Si-H addition was completed.

Claims

1. An epoxysilicon composition comprising an epoxy organosilicon and a salt of a carboxylic acid, wherein said epoxysilicon composition exhibits reduced tendency to gel on storage at room temperature compared to a composition containing the same ingredients as said epoxysilicon composition except the carboxylic acid salt.

2. A composition as in claim 1 wherein the epoxy organosilicon is selected from the group consisting of an epoxy silane and an epoxy silicone.

3. A composition as in claim 1 wherein the epoxy silane is an epoxy alkoxy silane.

4. The composition according to claim 1 wherein the salt is of the formula R6CO2M wherein M is selected from the group consisting of an alkali, alkaline earth, transition metal, and an ammonium ion and R6 represents a monovalent hydrocarbon group having one to 50 carbon atoms, optionally substituted with amino, hydroxyl, carboxyl or ester groups.

5. The composition of claim 4 wherein R6 is a linear or branched alkyl of one to ten carbon atoms.

6. The composition as in claim 4 wherein the carboxylic acid salt is ammonium or sodium propionate.

7. A process comprising reacting:

a) an ethylenically unsaturated epoxide of the formula:

2

where R is a single bond or an alkylene optionally containing alkyl pendant groups; R1 is a hydrogen, alkyl, straight, branched, or cyclic; R2 and R3 are individually hydrogen, straight, branched or cyclic alkyl, or any two of R1, R2 and R3, taken together are alkylene and combined with the carbon atom or atoms to which they are attached form a 5 to 12 carbon cyclic ring, optionally containing alkyl pendants; and the number of carbon atoms in R, R1, R2, and R3 are such that the total number of carbon atoms in the epoxide is from 4 to 50, with

b) an organosilicon hydride selected from the group consisting of hydridosilane and hydrido organosiloxane, in the presence of

c) a catalytically effective amount of platinum catalyst and

d) a member selected from the group consisting of carboxylic acid salt, hydroxy acid, amino acid and polymeric acid,

wherein said process exhibits reduced tendency to undergo unwanted side-reactions selected from the group consisting of epoxide ring-opening polymerization and olefin isomerization compared to a process comprising steps a), b) and c) but not step d).

8. The process of claim 7 wherein the hydridosilane is an alkoxysilane with the general formula R4n(OR4)3−mSiH, wherein R4 is a branched or linear alkyl group of 1 to 18 carbon atoms, a cyclic alkyl group of four to eight carbon atoms or an aryl, alkaryl, or aralkyl group of six to twelve carbon atoms, optionally containing halogen, oxygen, or nitrogen substituents with the proviso that such substituents do not interfere with either hydrosilation or promotion, and n is an integer selected from 0, 1, and 2.

9. The process of claim 8 wherein the alkoxysilane is trimethoxysilane, triethoxysilane, methyldimethoxysilane or methyldiethoxysilane.

10. The process of claim 7 wherein the hydrido organosiloxane possesses the general formula [Ra(H)bSiO(4−a−b)/2]n wherein R represents a monovalent hydrocarbon radical, a has a value of from 1 to 2.99, b has a value of from 0.001 to 1, and the sum of a+b has a value of from 1.5 to 3.0 and n=2 to 400.

11. The process of claim 7 wherein the hydrido organosiloxane is MDxD′yM, where x=0 to 200, y=1 to 200, M=—O½Si(CH3)3, D′=—OSi(H)(CH3)—, and D=—OSi(CH3)2—.

12. The process in claim 7 wherein the ethylenically unsaturated epoxide is 4-vinylcyclohexene monoxide or butadiene monoxide.

13. The process in claim 7 wherein the carboxylic acid salt is represented by the formula R6CO2M wherein M is selected from the group consisting of an alkali, alkaline earth, transition metal, and an ammonium ion and R6 represents a monovalent hydrocarbon of one to 50 carbon atoms, optionally substituted with amino, hydroxyl, carboxyl or ester groups.

14. The process in claim 13 wherein R6 is a linear or branched alkyl of one to ten carbon atoms.

15. The process in claim 13 wherein the carboxylic acid salt is ammonium or sodium propionate.

16. The process as in claim 7 wherein the carboxylic acid salt is selected from the group consisting of lithium acetate, sodium acetate, potassium acetate, potassium benzoate, sodium trifluoroacetate, sodium propionate, calcium acetate, samarium (III) acetate, copper (II) acetate, copper (II) ethylhexanoate, indium (III) acetate, ammonium formate, ammonium acetate, ammonium isovalerate, ammonium 2ethylbutyrate, ammonium propionate, ammonium chloride and combinations thereof.

17. The process in claim 7 wherein the platinum catalyst is a solution of chloroplatinic acid.