Processes for the preparation of y-methacryloxypropylsilane compounds

Abstract: There are provided processes for the preparation of γ-methacryloxypropylsilane compounds which comprise carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing at least one of a hindered phenol compound and an aromatic amine compound to coexist in the reaction system with an alkylamine compound or an amide compound, or with a gas containing molecular oxygen, or with a phenol compound having an aminoalkylene group. By using these processes as provided, gelation of the reaction mixture in the reaction system and during the course of purification thereof by distillation can effectively be avoided, and the desired γ-methacryloxypropylsilane compounds can be obtained in good yield.

Description: This invention relates to processes for the preparation of γ-methacryloxypropylsilane compounds, and more particularly to a process for preparing γ-methacryloxypropylsilane compounds wherein allyl methacrylate is allowed to react with a hydrosilane compound in one stage to obtain the γ-methacryloxypropylsilane compounds in high yield without causing gelation of reaction mixture in the reaction system and during the course of purification by distillation. γ-methacryloxypropylsilane compounds such as γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropyltriethoxysilane have a hydrolyzable group which is reactive with inorganic substances, as well as an organic functional group in a molecule, and they are widely used as coupling agents. As a process for the preparation of such γ-methacryloxypropylsilane compounds as mentioned above, it is known to react, for example, allyl methacrylate with trichlorosilane in the presence of a platinum catalyst and to isolate γ-methacryloxypropyltrialkoxysilane as a product from the reaction mixture after treatment with alcohol. In this process, however, corrosive hydrogen chloride is formed during the γ-methacryloxypropylalkoxysilane synthesis. This process, therefore, involves disadvantages in that the removal of the hydrogen chloride is essential for carrying out the process and the chlorine content of the end product is increased. As a process for the preparation of γ-methacryloxypropylsilane compounds, in which removal of hydrogen chloride is not required and there is no risk of increasing the chlorine content of the end product, it is known to react allyl methacrylate with a hydrosilane compound such as trialkoxysilane in one stage (hydrosilyl reaction) in the presence of a platinum based catalyst, and to purify the reaction mixture by distillation. The process mentioned above, however, there was involves disadvantages in that gelation of the reaction mixture or product is caused by polymerization of the material, i.e. an allyl methacrylate during the course of the reaction, or polymerization of the reaction product, i.e. a γ-methacryloxypropylsilane compound during the course of its purification. As a result of such gelation occurring during the reaction and during purification, the yield of the γ-methacryloxypropylsilane compound decreases and it becomes difficult to isolate efficiently the γ-methacryloxypropylsilane compound from the reaction mixture containing the gel, because once the gel is formed it is sparingly soluble in the solvent and difficult to remove. Under such circumstances there has been proposed a process intended to inhibit the formation of the gel as described above, wherein a hydrosilane compound and allyl methacrylate are added simultaneously to a toluene solution containing 2,5-di-t-butylhydroquinone as a polymerization inhibitor and a chloroplatinic acid solution as a catalyst (see US-A-3 258 477). However, this process is economically disadvantageous in that large amounts of toluene must be used as the solvent. Furthermore, there have heretofore been proposed various processes aimed at preventing the gel formation by using diverse polymerization inhibitors, for example, phenol compounds such as hindered phenols, aromatic amine compounds such as diphenylenediamine, or aromatic sulfur compounds such as phenothiazine (see, for example, Japanese Patent Laid-Open Specifications Nos. 283983/1987 and 188689/1988). However, sufficient prevention of the gel formation in the reaction system and during the course of purification of the reaction mixture by distillation has not yet been achieved, and there is a strong and growing demand for a process capable of preventing effectively the gel formation described above. EP-A-0 247 501 describes a process for preparing methacryloxy containing organosilicon compounds comprising reacting an excess of a methacryloxy functional containing compound with an alkoxysilane or Si-H containing silicone in the presence of a platinum-containing hydrosilation catalyst and an inhibitor which may be a phenolic inhibitor, an aromatic amine or an aromatic sulphur compound, or combinations thereof. EP-A-0 277 023 describes a process for preparing a hydrosilation catalyst from chloroplatinic acid and, in Example 7, describes the production of γ-methacryloxypropyl trimethoxy silane in a yield of 86% by hydrosilation of allyl methacrylate. The present invention is intended to solve such problems associated with the prior art procedures as are mentioned above, and an object of the invention is to provide processes for the preparation of γ-methacryloxypropylsilane compounds by reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinium catalyst in one stage, wherein gelation of the reaction mixture in the reaction system and during the course of purification by distillation can be effectively prevented, thereby obtaining the product γ-methacryloxypropylsilane compound in good yield and at moderate cost. The first process for the preparation of γ-methacryloxypropylsilane compounds of the present invention is characterized by carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing at least one compound selected from a hindered phenol compound and an aromatic amine compound to coexist in the reaction system with an alkylamine compound. The second process for the preparation of γ-methacryloxypropylsilane compounds of the invention is characterized by carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing at least one compound selected from the group consisting of a hindered phenol compound and an aromatic amine compound to coexist in the reaction system with an amide compound. The third process for the preparation of γ-methacryloxypropylsilane compounds of the invention is characterized by carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing at least one compound selected from the group consisting of a hindered phenol compound and an aromatic amine compound to exist in the reaction system and blowing a gas containing molecular oxygen into the reaction mixture. The fourth process for the preparation of γ-methacryloxypropylsilane compounds of the invention is characterized by carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing a phenol compound having an aminoalkylene group to exist in the reaction system. The processes for the preparation of γ-methacryloxypropylsilane compounds of the present invention are described below in detail. The first to fourth processes for the preparation of γ-methacryloxypropylsilane compounds of the invention comprise carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing a specific polymerization inhibitor or a specific combination of polymerization inhibitors to exist in the reaction system. By the term hydrosilane compound as used herein is meant a compound having at least one Si-H bond, for example, the compound represented by the general formula [I], [II] or [III] as described below. wherein R 1 , R 2 and R 3 , which may be the same or different, are each alkyl or alkoxy. wherein R 4 is hydrogen or methyl, at least one of R 4 is hydrogen, and n is an integer of from 0 to 300. wherein m is an integer of from 3 to 10. Specific examples of the hydrosilane compound represented by the above formulae [I], [II] or [III] are triethoxysilane, trimethoxysilane, trimethylsilane, triethylsilane, tripropoxysilane, tributoxysilane, methyldimethoxysilane, ethyldimethoxysilane, methyldiethoxysilane, dimethylmethoxysilane, trioctyloxysilane, methyldioctyloxysilane, dimethyloctyloxysilane, 1,1,3,3-tetramethyldisiloxane, pentamethyldisiloxane, α,ω-dihydropolysiloxane, polysiloxane having Si-H bond between the molecular chains, 1,3,5,7-tetramethylcyclotetrasiloxane and 1,3,5,7,9-pentamethylcyclopentasiloxane. In the process for the preparation of γ-methacryloxypropylsilane compounds of the present invention, allyl methacrylate and a hydrosilane compound such as exemplified above are used in the proportion in terms of the (allyl methacrylate/hydrosilyl group of the hydrosilane compound) molar ratio of usually 0.66/1.5, preferably 0.83/1.2. In the present invention any platinum catalyst previously used in the hydrosilylation reaction may be used as the catalyst. However, preferred platinum catalysts in the invention include chloroplatinic acid, dichlorobis(acetonitrile)platinum (II), dichlorodiethylene platinum (II), dichloro(1,5-cyclooctadiene)platinum (II), platinum vinylsiloxane complex, and supported platinum such as platinum supported on activated carbon or platinum supported on alumina. The above-exemplified platinum catalyst is used in an amount, based on the allyl methacrylate used, of usually from 1 x 10 -7 to 1 x 10 -3 mole, preferably from 1 x 10 -6 to 1 x 10 -4 mole. In the first process of the invention for the preparation of γ-methacryloxypropylsilane compounds, the reaction of the above-described hydrosilane compound with allyl methacrylate is carried out in the presence of the above-described platinum catalyst, while allowing at least one compound selected from a hindered phenol compound and an aromatic amine compound to coexist in the reaction system with an alkylamine compound. The hindered phenol compound used in the first process of the invention has at least one bulky substituent at the position near the hydroxy group in the aromatic ring, and may be any of the hindered phenol compounds used previously as a polymerization inhibitor in the hydrosilylation reaction. Such hindered phenol compounds as mentioned above include specifically those listed below and showing their respective structural formulae in which tBu represents -C(CH 3 ) 3 (t-butyl). (1) 2,6-di-t-butyl-p-cresol (BHT) (2) 2,6-di-t-butylphenol (3) 2-methyl-6-t-butyl-p-cresol (MBPC) (4) 2-t-butyl-4-methoxyphenol (5) 2,5-di-t-butylhydroquinone (trade name: Antage DBH, a product of Kawaguchi Kagaku K.K.) (6) n-octadecyl-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate (trade name: Irganox® 1076, a product of Ciba-Geigy) (7) 4,4′-methylene-bis(2,6-di-t-butylphenol) (trade name: Ethanox® 702, a product of Ethyl Co.) (8) 2,2′-methylene-bis(4-methyl-6-t-butylphenol) (9) 2,2′-ethylidene-bis(4,6-di-t-butylphenol) (trade name: Isonox® 129, a product of Schenectady Co.) (10) 2,2′-butylidene-bis(6-t-butyl-4-methylphenol) (trade name: Sumilizer® BBP, a product of Sumitomo Kagaku Kogyo K.K.) (11) 4,4′-butylidene-bis(2-t-butyl-5-methylphenol) (12) 2-t-butyl-6-(3′-t-butyl-5′-methyl-2′-hydroxybenzyl)-4-methylphenyl acrylate (trade name: Sumilizer® GM, a product of Sumitomo Kagaku Kogyo K.K.) (13) tetrakis{methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate}methane (trade name: Irganox® 1010, a product of Ciba-Geigy) (14) (mono, di, tri)α-methylbenzylphenol The hindered phenol compounds as exemplified above are used in an amount, based on the allyl methacrylate used, of from 1 ppm to 20% by weight, preferably from 10 ppm to 5% by weight. The aromatic amine compound used in the first process of the invention includes specifically those as is exemplified below. (1) N,N′-diphenyl-p-phenylenediamine (2) N-pheny-β-naphthylamine (trade name: Antage C®, a product of Kawaguchi Kagaku K.K.) (3) 4,4′-dioctyl-diphenylamine (4) phenothiazine The aromatic amine compounds as exemplified above are used in an amount, based on the allyl methacrylate used, of from 1 ppm to 20% by weight, preferably from 10 ppm to 5% by weight. In the first process for the preparation of γ-methacryloxypropylsilane compounds of the invention, an alkylamine compound is used together with at least one of the above-mentioned hindered phenol compounds and aromatic amine compounds. The alkylamine compound used in the invention may be a primary, secondary or tertiary amine which may also be silylated. The alkylamine compound as used herein includes specifically primary alkylamine compounds such as ethylamine, n-propylamine, isobutylamine, t-butylamine, n-hexylamine, cyclohexylamine, n-octylamine, n-pentylamine, n-heptylamine, n-nonylamine, n-decylamine, n-dodecylamine, n-octadecylamine and benzylamine; secondary amine compounds such as diethylamine, dipropylamine, dibutylamine, dioctylamine, dihexylamine and dibenzylamine; and tertiary amine compounds such as triethylamine, tripropylamine, tributylamine, tris(2-ethylhexyl)amine, tri(n-octyl)amine, tribenzylamine, benzyldimethylamine, diethylaminotrimethylsilane {(CH 3 CH 2 ) 2 NSi(CH 3 ) 3 }, diazabicyclo[2.2.2]octane and quinuclidine As alkylamine compounds, there may also be used phenol compounds having an aminoalkylene group as is described later, which are used in the fourth process of the invention. The alkylamine compounds as described above are used in an amount, based on the amount of platinum catalyst used, of usually more than one equivalent, preferably 1-500 equivalents and more preferably 10-200 equivalents. In the second process of the invention for the preparation of γ-methacryloxypropylsilane compounds, an amide compound is used together with at least one compound selected from the above-mentioned hindered phenol compounds and aromatic amine compounds. The amide compound used herein includes specifically N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylacetamide, N,N-dimethylpropionamide, N-methylacetamide, N-methylformamide, and, in addition, those exemplified below. (1) N-t-butylacetoacetamide (2) N,N′-bis-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionylhexamethylenediamine (trade name: Irganox® 1098, a product of Ciba-Geigy) (3) tris[2-(3′,5′-di-t-butyl-4′-hydroxyhydrocinnamoyloxy)ethyl]isocyanurate (trade name: Irganox® 3125, a product of Ciba-Geigy) In the above formula [A], R is represented by the following formula: (4) tris(3,5-di-t-butyl-hydroxybenzyl)isocyanurate (trade name: Irganox® 3114, a product of Ciba-Geigy) The compound has the formula [A], provided that R is represented by the following formula: (5) tris(4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)isocyanurate (trade name: Cyanox® 1790, a product of ACC Co.) The compound has the formula [A], provided that R is represented by the following formula: The amide compounds used in the invention may be used either singly or in combination of two or more. In either case, the effective amount of the amide compound used, based on the platinum based catalyst, is more than 1 equivalent, preferably 1-10 equivalents. In the third process of the invention for the preparation of γ-methacryloxypropylsilane compounds, the reaction of allyl methacrylate with a hydrosilane compound is carried out in the presence of the platinum catalyst, while allowing at least one compound selected from the above-mentioned hindered phenol compound and aromatic amine compound to exist in the reaction system and simultaneously blowing a gas containing molecular oxygen into the reaction mixture containing these compounds as described above. The gas containing molecular oxygen used in the process of the invention includes a gaseous mixture with an inert gas such as nitrogen or argon, or air or oxygen. The gas containing molecular oxygen preferably contains 0.1-20% oxygen by volume, preferably 0.1-2% of oxygen by volume for safety. In the third process of the invention, the gas containing molecular oxygen is blown into the reaction mixture at such a rate that the amount of oxygen molecules, based on 1 mol of the allyl methacrylate used, is usually from 1 x 10 -7 to 5 x 10 -4 mol/min, preferably from 1 x 10 -5 to 3 x 10 -4 mol/min. In the fourth process of the invention for the preparation of γ-methacryloxypropylsilane compounds, the above-mentioned hydrosilane compound is reacted with allyl methacrylate in the presence of the above-mentioned platinum catalyst, while allowing a phenol compound having an aminoalkylene group to exist in the reaction system. The phenol compound having an aminoalkylene group used in the fourth process of the invention includes those exemplified below. (1) 4-(2-aminoethyl)phenol (2) 4-(N,N-dimethylaminomethyl)-2,6-di-t-butylphenol (trade name: Ethanox® 703, a product of Ethyl Co.) (3) 2-(3,5-di-t-butyl-4-hydroxybenzyl)-2-n-butylmalonic acid-bis(1,2,2,6,6-pentamethyl-4-piperidyl) (trade name: TINUVIN® 144, a product of Ciba-Geigy) (4) 4-(N,N-dibutylaminomethyl)-2,6-di-t-butylphenol (5) N-methyl-bis(3,5-di-t-butyl-4-hydroxybenzyl)amine The phenol compound having an aminoalkylene group as exemplified above is used in an amount, based on the platinum catalyst used, of usually more than 1 equivalent, preferably 1-10,000 equivalents and more preferably 10-1,000 equivalents. The first to fourth processes of the invention for the preparation of γ-methacryloxypropylsilane compounds by using the starting materials, catalyst and polymerization inhibitor as exemplified hereinbefore may be carried out either in the presence or absence of a reaction solvent. The reaction solvent used in the processes of the invention includes, for example, aromatic compounds such as benzene, toluene and xylene, aliphatic compounds such as hexane and heptane, and ether compounds such as tetrahydrofuran. In the processes of the invention, the reaction temperature employed is usually 40-130°C, preferably 60-120°C, and the order of addition of the starting materials, catalyst and polymerization inhibitor is not particularly limited. Furthermore, the processes of the present invention may be carried out in an atmosphere of either oxygen or nitrogen. In the present invention allyl methacrylate is allowed to react with the hydrosilane compound as described above to obtain the reaction mixture and then the reaction mixture is subjected to purification by distillation to isolate the γ-methacryloxypropylsilane compound. In the purification step, a compound selected from the above hindered phenol compound and aromatic amine compound may be added, as a polymerization inhibitor, to the reaction mixture to inhibit the gelation of the reaction mixture more effectively. Further, as the polymerization inhibitor, a compound selected from the hindered phenol compound and the aromatic amide compound may be added with an alkylamine compound, amide compound or phenol compound having aminoalkylene group to the reaction mixture. The polymerization inhibitor used in the purification may be the same as or different from that used in the reaction of the allyl methacrylate with the hydrosilane compound. The polymerization inhibitor used in the purification by distillation is used in a total amount, based on the platinum catalyst, of usually 1-5,000 equivalents and more preferably 10-1,000 equivalents. According to the first to fourth processes for the preparation of γ-methacryloxypropylsilane compounds of the present invention, since the reaction of allyl methacrylate with the hydrosilane compound in the presence of the platinum catalyst is carried out in the presence of at least one compound selected from the hindered phenol compounds and aromatic amine compounds in addition to the alkylamine compound, amide compound, molecular oxygen, or in the presence of the phenol compound having an aminoalkylene group, gel formation of the reaction mixture during the reaction or during the course of purification by distillation can be effectively avoided, and the γ-methacryloxypropylsilane compounds desired can be prepared in good yield. The processes for the preparation of γ-methacryloxypropylsilane compounds of the present invention are illustrated below in more detail with reference to examples, but it should be understood that the invention is in no way limited to those examples. In the examples, percent (%) used is mol% based on the allyl methacrylate used. Example 1 A nitrogen-purged four neck flask equipped with a reflux condenser, a stirrer, a thermometer and a dropping funnel was charged with 126 g of allyl methacrylate, 0.1 ml of a solution of chloroplatinic (IV) acid in isopropanol (corresponding to 10 -5 mol of platinum) and 3 g of tetrakis (methylene-3-(3′,5′-di-t-butyl-4′-hydroxyphenyl)propionate) methane (Irganox® 1010, a product of Chiba-Geigy) as a radical polymerization inhibitor. The flask was then charged with 0.1 g of triethylamine, heated at 80°C by means of an oil bath, and charged dropwise 122 g of trimethoxysilane by means of the dropping funnel over a period of 1 hour. The flask was then kept at 80°C for 3 hours. On analysis of the reaction mixture by gas chromatography, it was found that the reaction gave the γ-methacryloxypropyltrimethoxysilane in 88% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. The reaction mixture was then distilled to isolate the end product. Results obtained are shown in Table 2. Example 2 The same procedure as described in Example 1 was repeated to carry out the reaction and the isolation of the end product, except that 0.06 g of dibutylamine was used in place of 0.1 g of the triethylamine for the reaction. Results obtained on analysis of the reaction mixture by gas chromatography and GPC are shown in Table 1, and results obtained on purification of the reaction mixture by distillation are shown in Table 2. Examples 3-11 The same procedure as described in Example 1 was repeated to carry out the reaction and the isolation of the end product, except that radical polymerization inhibitors and alkylamine compounds shown in Table 1 were used individually and the reaction was carried out at a temperature as shown in Table 1. Results obtained on analysis of the reaction mixture by gas chromatography and GPC are shown in Table 1, and results obtained on purification of the reaction mixture by distillation are shown in Table 2. Comparative Example 1 The same procedure as described in Example 1 was repeated to carry out the reaction except that the 0.1 g of the triethylamine was not added to the reaction system. At the time when about 1/3 of the trimethoxysilane was added dropwise to the flask, the reaction mixture in the flask completely set to gel. Example 12 The same procedure as described in Example 5 was repeated to carry out the reaction except that 164 g of triethoxysilane was used in place of 122 g of the trimethoxysilane. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltriethoxysilane was obtained in 85% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product. Results obtained are shown in Table 2. Example 13 The same procedure as described in Example 1 was repeated to carry out the reaction except that 148 g of pentamethyldisiloxane was used in place of 122 g of the trimethoxysilane. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropylpentamethyldisiloxane was obtained in 80% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product. Results obtained are shown in Table 2. Example Yield of isolated γ-methacryloxypropylsilanes Distiller bottom polymer (%) 1 84 0 2 80 0.8 3 82 0.1 4 82 0.5 5 81 0 6 80 0.3 7 76 0.7 8 81 0 9 79 0.2 10 78 0 11 80 0 12 80 0 13 74 0.3 Example 14 The same procedure as described in Example 8 was repeated to carry out the reaction except that 3.7 mg of dichloro(1,5-cyclooctadiene)platinum (II) was used in place of 0.1 ml of a solution of chloroplatinic (IV) acid in isopropanol. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 87% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 exists therein. Subsequently, the reaction mixture was distilled to isolate the end product in 80% yield without causing gelation thereof. Example 15 The same procedure as described in Example 12 was repeated to carry out the reaction except that a solution of 1,3-divinyltetramethylsiloxane/platinum complex in toluene (corresponding to 1 x 10 -5 mol of platinum) was used in place of 0.1 ml of the solution of the chloroplatinic (IV) acid in isopropanol. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltriethoxysilane was obtained in 85% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product in 78% yield without causing gelation thereof. Example 16 The same procedure as described in Example 1 was repeated to carry out the reaction except that 100 ml of toluene was used as a reaction solvent. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 90% yield, and on analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product in 85% yield without causing gelation thereof. Example 17 The same procedure as described in Example 5 was repeated to carry out the reaction except that 150 ml of n-hexane was used as a reaction solvent. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 88% yield, and on analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product in 83% yield without causing gelation thereof. Comparative Example 2 The same procedure as described in Example 16 was repeated to carry out the reaction except that the 0.1 g of the triethylamine was not added to the reaction system. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 65% yield. Subsequently, the reaction mixture was distilled to isolate the end product merely in 40% yield, bringing about a gel formed in the distiller bottom. Example 18 The same procedure as described in Example 1 was repeated to carry out the reaction except that 300.6 g of pentamethylcyclopentasiloxane as shown below was used in place of 122 g of the trimethoxysilane. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropylpentamethylcyclopentasiloxane was obtained in 64% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Example 19 The same procedure as described in Example 1 was repeated to carry out the reaction except that in place of 122 g of the trimethoxysilane, there was used 500 g of polymethylhydrogensiloxane (100 cSt: content of SiH group 10%) represented by the following formula. On analysis of the reaction mixture by gas chromatography, it was found that the conversion of allyl methacrylate is 85%, and no polymerizate was formed. Example 20 The same procedure as described in Example 3 was repeated to carry out the reaction except that the amount of the tri-n-octylamine used was changed from 0.35 g to 3.5 mg. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 83% yield. On analysis of the reaction mixture by GPC, it was confirmed that the amount of a polymerizate having a molecular weight of more than 2,000 as formed was 2.3% based on the starting materials. Subsequently, the reaction mixture was distilled to isolate the end product in 75% yield, and no gelation took place though the amount of the polymerizate increased to 5%. Example 21 0.7 g of tri-n-octylamine was added, to the reaction mixture obtained in Example 20 and the resulting mixture was distilled, whereby γ-methacryloxypropyltrimethoxysilane was isolated in 78% yield, and no increase of the polymerizate was observed. Example 22 The same procedure as described in Example 8 was repeated to carry out the reaction except that 0.14 g of 4-(2-aminoethyl)phenol was used in place of 0.15 g of Ethanox® 703. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 82% yield. Subsequently, the reaction mixture was distilled to isolate the end product in 75% yield, and no gelation took place. Example 23 A nitrogen-purged four neck flask equipped with a reflux condenser, a stirrer, a thermometer and a dropping funnel was charged with 126 g of allyl methacrylate, 0.1 ml of a solution of chloroplatinic (IV) acid in isopropanol (corresponding to 10 -5 mol of platinum) and 2.8 g of 2,2′-ethylidenebis-(4,6-t-butylphenol) (trade name: Isonox® 129, a product of Schenectady Co.) as a radical polymerization inhibitor. Subsequently, the flask was charged with 17.4 mg of N,N-dimethylacetamide, heated at 80°C by means of an oil bath, and then charged dropwise with 122 g of trimethoxysilane by means of the dropping funnel over a period of 1 hour. The flask was then kept at 80°C for 5 hours. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 83% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product, whereby no gelation took place. Results obtained are shown in Table 4. Example 24 The same procedure as described in Example 23 was repeated to carry out the reaction and isolate the end product except that 21.9 mg of N-methylacetamide was used in place of 17.4 mg of the N,N-dimethylacetamide. Results obtained on analysis of the reaction mixture by gas chromatography and by GPC are shown in Table 3, and results obtained on purification of the reaction mixture by distillation are shown in Table 4. Examples 25-32 The same procedure as described in Example 23 was repeated to carry out the reaction and isolate the end product except that radical polymerization inhibitors, hydrosilane compounds and amide compounds as shown in Table 3 were used individually, and the reaction was carried out at each temperature as shown in Table 3. Results obtained on analysis of the reaction mixture by gas chromatography and by GPC are shown in Table 3, and results obtained on purification of the reaction mixture by distillation are shown in Table 4. Example Yield of γ-methacryloxypropyl-silanes isolated (%) Distiller bottom polymer (%) 23 77 2 24 79 0.8 25 80 0.1 26 78 0.5 27 79 0.1 28 76 0.2 29 80 0.1 30 80 0.1 31 77 0.3 32 68 0.1 Comparative Example 3 The same procedure as described in Example 23 was repeated to carry out the reaction except that the 17.4 mg of the N,N-dimethylacetamide was not added to the reaction system. At the time when about 1/3 of the trimethoxysilane had been added dropwise to the reaction system the reaction mixture in the flask completely set to gel. Example 33 The same procedure as described in Example 23 was repeated to carry out the reaction except that 0.2 ml of a solution of 1,3-divinyltetramethylsiloxane/platinum complex in toluene (corresponding to 10 -5 mol of platinum) was used in place of 0.1 ml of the solution of chloroplatinic (IV) acid in isopropanol. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 84% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product in 79% yield without causing gelation thereof. Example 34 The same procedure as described in Example 24 was repeated to carry out the reaction except that 3.7 mg of dichloro(1,5-cyclooctadiene)platinum (II) was used in place of 0.1 ml of the solution of chloroplatinic (IV) acid in isopropanol. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 86% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product in 80% yield without causing gelation thereof. Example 35 The same procedure as described in Example 23 was repeated to carry out the reaction except that 500 g of polymethylhydrogensiloxane (100 cSt: the content of SiH group 10%) represented by the following formula. On analysis of the reaction mixture by gas chromatography, it was found that the conversion of allyl methacrylate was 90%. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Example 36 The same procedure as described in Example 23 was repeated except that 100 ml of toluene was used as a reaction solvent. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 87% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product in 81% yield without causing gelation thereof, and the polymer in the distillation residue was 1.5%. Example 37 The same procedure as described in Example 23 was repeated to carry out the reaction except that 100 ml of n-hexane was used as a reaction solvent. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 88% yield. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate having a molecular weight of more than 2,000 existed therein. Subsequently, the reaction mixture was distilled to isolate the end product in 81% yield without causing gelation thereof, and the polymer in the distillation residue was 1.0%. Comparative Example 4 The same procedure as described in Example 36 was repeated to carry out the reaction except that the 17.4 mg of the N,N-dimethylacetamide was not added to the reaction system. On analysis of the reaction mixture by gas chromatograph, it became a viscous solution, though no gelation thereof took place, and it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 65% yield. Subsequently, the reaction mixture was distilled to isolate the end product merely in 40% yield, forming a gel in the distiller bottom. Example 38 To the reaction mixture obtained in Example 23, 87.1 mg of N,N-dimethylacetamide was added, and the resulting mixture was distilled to isolate the end product, whereby γ-methacryloxypropyltrimethoxysilane was isolated in 79% yield without causing gelation thereof, and the polymer in the distillation residue was 0.4%. Example 39 The same four neck flask as used in Example 23 but having a gas blowing head was charged with 126 g of allyl methacrylate,0.1 ml of a solutionof chloroplatinic (IV) acid in isopropanol (corresponding to 10 -5 mol of platinum) and 1.0 g of 2,6-di-t-butyl-p-cresol (BHT) as a radical polymerization inhibitor, followed by heating at 80°C on an oil bath. Subsequently, into the reaction liquid was blown through the gas blowing head with O 2 /N 2 gas containing 2% of oxygen by volume at a rate of 300 ml/min based on 1 mol of the allyl methacrylate. While continuing the blowing of the gas, 122 g of trimethoxysilane was added dropwise by means of the dropping funnel to the reaction liquid over a period of 1 hour, and the heating was continued at 80°C for 5 hours. The gas blowing was further continued after the completion of the addition of the trimethoxysilane. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was formed in 83% yield. On analysis of the reaction mixture by GPC, it was confirmed that a polymerizate having a molecular weight of more than 2,000 in the reaction mixture was less than 0.1%. Examples 40-43 The same procedure as described in Example 39 was repeated to carry out the reaction and isolate the end product except that the reaction was carried out using radical polymerization inhibitors as shown in Table 5. Results obtained on analysis of the reaction mixture by gas chromatography and by GPC are shown in Table 5. Comparative Example 5 The same procedure as described in Example 39 was repeated to carry out the reaction except that N 2 gas was used as the blowing gas. In the course of the reaction, the reaction mixture present in the flask set to gel. Results obtained are shown in Table 5. Comparative Example 6 The same procedure as described in Comparative Example 5 was repeated to carry out the reaction except that 3 g of 4,4′-methylene-bis(2,3-di-t-butylphenol) (trade name: Ethanox® 702, a product of Ethyl Co.) was used as a radical polymerization inhibitor. Results obtained on analysis of the reaction mixture by gas chromatography and by GPC are shown in Table 5. Comparative Example 7 The same procedure as described in Example 39 was repeated to carry out the reaction except that no radical polymerization inhibitor was used. Results obtained on analysis of the reaction mixture by gas chromatography and by GPC are shown in Table 5. Example 44 The same procedure as described in Example 39 was repeated to carry out the reaction except that O 2 /N 2 gas containing 20% of oxygen by volume was used as the blowing gas. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 84% yield. On analysis of the reaction mixture by GPC, it was confirmed that a polymerizate having a molecular weight of more than 2,000 therein was less than 0.1%. Example 45 The same procedure as described in Example 39 was repeated except that O 2 /N 2 gas containing 0.2% of oxygen by volume was used as the blowing gas. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 85% yield. On analysis of the reaction mixture by GPC, it was confirmed that a polymerizate having a molecular weight of more than 2,000 therein was less than 0.1%. Example 46 The same procedure as described in Example 39 was repeated to carry out the reaction except that 0.26 ml of a solution of 1,3-divinyltetramethylsiloxane/platinum complex in toluene (corresponding to 10 -5 mol of platinum) was used in place of 0.1 ml of the solution of chloroplatinic (IV) acid in isopropanol. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 85% yield. On analysis of the reaction mixture by GPC, it was confirmed that a polymerizate having a molecular weight of more than 2,000 therein was less than 0.1%. Example 47 The same procedure as described in Example 41 was repeated to carry out the reaction except that 3.7 mg of dichloro(1,5-cyclooctadiene)platinum (II) was used in place of 0.1 ml of the solution of chloroplatinic (IV) acid in isopropanol. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane was obtained in 82% yield. On analysis of the reaction mixture by GPC, it was confirmed that a polymerizate having a molecular weight of more than 2,000 therein was less than 0.1%. Example 48 The same procedure as described in Example 39 was repeated except that 500 g of polymethylhydrogensiloxane (100 cSt: the content of SiH group 10%) was used as the hydrosilane compound. On analysis of the reaction mixture by gas chromatography, it was found that the conversion of the allyl methacrylate was 93%. On analysis of the reaction mixture by GPC, it was confirmed that no polymerizate of a high molecular weight existed therein. Example 49 The same procedure as described in Example 39 was repeated except that 100 ml of toluene was used as a reaction solvent. On analysis of the reaction mixture by gas chromatography, it was found that γ-methacryloxypropyltrimethoxysilane is obtained in 84% yield. Comparative Example 8 The same procedure as described in Example 39 was repeated to carry out the reaction except that prior to charging the flask with the starting materials, platinum catalyst and radical polymerization inhibitor, the flask was purged with dry air and no gas-blowing was carried out. In the course of the reaction the reaction mixture became viscous and set to a gel.

Claims: A process for the preparation of γ-methacryloxypropylsilane compounds which process comprises reacting allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst characterised in that there is also present in the reaction system at least one compound selected from a phenol having an aminoalkylene group, a hindered phenol and an aromatic amine, and when a hindered phenol and/or an aromatic amine is present in the reaction system there is also present an alkylamine, an amide, tris [2-(3',5'-di-t-butyl-4'-hydroxyhydrocinnamoyloxy) ethyl]isocyanurate, tris (3,5-di-t-butyl-hydroxybenzyl)isocyanurate, tris (4-t-butyl-2,6-dimethyl-3-hydroxybenzyl)isocyanurate or a gas containing molecular oxygen. A process as claimed in claim 1 which process comprises carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing at least one of a hindered phenol compound and an aromatic amine compound to coexist in the reaction system with an alkylamine compound. The process as claimed in claim 2 wherein the alkylamine compound is a phenol compound having an aminoalkylene group. A process as claimed in claim 1 which process comprises carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst to obtain a reaction product, while allowing at least one of a hindered phenol compound and an aromatic amine compound to coexist in the reaction system with an amide compound. The process as claimed in claim 4 wherein a further amount of amide compound is added to the reaction mixture obtained, and the resulting reaction mixture is purified by distillation. A process as claimed in claim 1 which process comprises carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing at least one of a hindered phenol compound and an aromatic amine compound to exist in the reaction system and blowing a gas containing molecular oxygen into the reaction solution. A process as claimed in claim 1 which process comprises carrying out the reaction of allyl methacrylate with a hydrosilane compound in the presence of a platinum catalyst, while allowing a phenol compound having an aminoalkylene group to exist in the reaction system.

Inventors: ISHII MASAAKI, ISHIKAWA MASAKO, OGAWA HIDEAKI, OKUMURA YOSHIHARU, SHINOHARA AKIHITO, SHIOZAWA KOUJI, TAKATSUNA KAZUTOSHI, ISHII, MASAAKI, ISHIKAWA, MASAKO, OGAWA, HIDEAKI, OKUMURA, YOSHIHARU, SHINOHARA, AKIHITO, SHIOZAWA, KOUJI, TAKATSUNA, KAZUTOSHI
Applicants: TONEN CORP, TONEN CORPORATION
Application year: 1991
Main classification: C07F7
IPC codes: C08G77, C07F7