| PATENT NUMBER | This data is not available for free |
| PATENT GRANT DATE | 09.01.01 |
| PATENT TITLE |
Pheno-functional organosilicon compounds and method for the preparation |
| PATENT ABSTRACT |
wherein A is hydrogen or a residue afforded by the removal of n hydroxyl groups from an m-valent alcohol, each R is independently a monovalent hydrocarbon group free of aliphatic unsaturation, each R.sup.1 is independently a divalent hydrocarbon group containing at least 2 carbon atoms, m and n are natural numbers wherein m.gtoreq.n, p is 0 or 1, and Y is a phenol group having the formula: ##STR2## wherein R.sup.3 is alkyl and q is from 0 to 4. Also, a method of preparing a phenol-functional organosilicon compound. |
| PATENT INVENTORS | This data is not available for free |
| PATENT ASSIGNEE | This data is not available for free |
| PATENT FILE DATE | March 21, 2000 |
| PATENT FOREIGN APPLICATION PRIORITY DATA | This data is not available for free |
| PATENT CLAIMS |
That which is claimed is: 1. A phenol-functional organosilicon compound having the formula: ##STR24## wherein A is hydrogen or a residue afforded by the removal of n hydroxyl groups from an m-valent alcohol, each R is independently a monovalent hydrocarbon group free of aliphatic unsaturation, each R.sup.1 is independently a divalent hydrocarbon group containing at least 2 carbon atoms, m and n are natural numbers wherein m.gtoreq.n, p is 0 or 1, and Y is a phenol group having the formula: ##STR25## wherein R.sup.3 is alkyl and q is from 0 to 4. 2. The phenol-functional organosilicon compound according to claim 1, wherein A is hydrogen, alkyl, an aliphatically unsaturated group, or a hydroxyl-functional alkenyloxyalkylene group. 3. The phenol-functional organosilicon compound according to claim 2, wherein A is an aliphatically unsaturated group. 4. The phenol-functional organosilicon compound according to claim 1, wherein R.sup.3 is methyl. 5. The phenol-functional organosilicon compound according to claim 1, wherein m and n are each from 1 to 5. 6. The phenol-functional organosilicon compound according to claim 1, wherein q is 0 or 1. 7. A method of preparing a phenol-functional organosilicon compound, said method comprising the steps of: (A) reacting an aliphatically unsaturated SiH-functional organosilicon compound in the presence of a hydrosilylation catalyst to form an addition reaction product, wherein the SiH-functional organosilicon compound has the formula: ##STR26## wherein each R is independently a monovalent hydrocarbon group free of aliphatic unsaturation, R.sup.2 is an aliphatically unsaturated monovalent hydrocarbon group, R.sup.3 is alkyl, p is 0 or 1, and q is from 0 to 4; and (B) reacting the addition reaction product with an alcohol or water to produce a phenol-functional organosilicon compound, wherein the alcohol has the formula A(OH).sub.n wherein A is hydrogen or a residue afforded by the removal of n hydroxyl groups from an m-valent alcohol and m and n are natural numbers wherein m.gtoreq.n. 8. The method according to claim 7, wherein A in the formula of the alcohol is hydrogen, alkyl, an aliphatically unsaturated group, or a hydroxyl-functional alkenyloxyalkylene group. 9. The method according to claim 8, wherein A in the formula of the alcohol is an aliphatically unsaturated group. 10. The method according to claim 7, wherein R.sup.3 is methyl. 11. The method according to claim 7, wherein m and n are each from 1 to 5. 12. The method according to claim 7, wherein q is 0 or 1. 13. The method according to claim 7, wherein the SiH-functional organosilicon compound is dimethylsilyl ether of allyl phenol or dimethylsilyl ether of eugenol. 14. The method according to claim 7, wherein the hydrosilylation catalyst is a platinum compound. 15. The method according to claim 7, wherein the alcohol is used in an amount such that the ratio of the number of equivalents of hydroxyl groups in the alcohol to the number of equivalents of silyl ether groups in the SiH-functional organosilicon compound is from 1.0 to 5.0. 16. The method according to claim 7, wherein the water is used in an amount such that the ratio of the number of equivalents of hydroxyl groups in the water to the number of equivalents of silyl ether groups in the SiH-functional organosilicon compound is from 1.0 to 5.0. 17. The method according to claim 7, wherein step (A) is carried out by first mixing the hydrosilylation catalyst with a solvent to form a mixture and then slowly adding the SiH-functional organosilicon compound dropwise to the mixture. 18. The method according to claim 7, wherein step (A) is carried out at from 50 to 200.degree. C. 19. The method according to claim 7, further comprising the step of purifying the phenol-functional organosilicon compound by distillation. |
| PATENT DESCRIPTION |
FIELD OF THE INVENTION The present invention relates to phenol group-containing organosilicon compounds, hereinafter referred to as phenol-functional organosilicon compounds, and to a method for the preparation thereof. BACKGROUND OF THE INVENTION A number of phenol-functional organosilicon compounds and methods for their synthesis are known. For example, U.S. Pat. No. 3,622,609 teaches a method for the synthesis of 1,3-bis-.gamma.-(ortho-hydroxyphenyl)propyl- 1,1,3,3-tetramethyldisiloxane by the dimethylsilylation of the hydroxyl group in 2-allylphenol, hydrosilylation polymerization of the reaction product, and then ring opening with sodium hydroxide followed by treatment with sulfuric acid. However, this method cannot provide compounds containing both a phenol group and a functional group other than a phenol group. Japanese Laid Open (Kokai or Unexamined) Patent Application Numbers Hei 2-166123 (166,123/1990) and Hei 2-225524 (225,524/1990) describe a method for synthesizing phenol-functional organosiloxanes by carrying out an addition reaction between an SiH-functional organosiloxane and tert-butoxystyrene (phenolic hydroxyl protected by the tert-butyl group) followed by de-tert-butylation in the presence of a strong acid. This method is, however, unable to produce compounds that contain the phenol group and alkenyl in the same molecule and also suffers from the disadvantage that the siloxane chain is susceptible to cleavage by the strong acid. Otherwise, Japanese Laid Open (Kokai or Unexamined) Patent Application Numbers Sho 62-275116 (275,116/1987) and Sho 61-84022 (84,02211986) describe phenol-functional silanes, but these compounds are limited to phenol-functional trialkylsilanes and do not include alkoxysilyl-functional or silanol-functional species. Moreover, the synthetic methods disclosed therein are very complex and do not provide high yields. The present inventors have already disclosed organosiloxanes that contain both alkenyl and the phenol group as well as a method for the synthesis thereof (Japanese Patent Application Number Hei 10-294580 (294,580/1998)). Unfortunately, this method carries with it the risk that the alkenyl group-containing organosiloxane product will polymerize during the purification phase. In addition, this method cannot be used to synthesize compounds that contain both the phenol group and alkoxysilyl group or silanol group in the same molecule. SUMMARY OF THE INVENTION In specific terms, an object of this invention is to provide novel phenol-functional organosilicon compounds containing both a phenol group and alkoxysilyl, alkenyl, or silanol group in the same molecule. An additional object of this invention is to provide a method for preparing the novel phenol-functional organosilicon compounds. The present invention is directed to a phenol-functional organosilicon compound having the formula: ##STR3## wherein A is hydrogen or a residue afforded by the removal of n hydroxyl groups from an m-valent alcohol, each R is independently a monovalent hydrocarbon group free of aliphatic unsaturation, each R.sup.1 is independently a divalent hydrocarbon group containing at least 2 carbon atoms, m and n are natural numbers wherein m.gtoreq.n, p is 0 or 1, and Y is a phenol group having the formula: ##STR4## wherein R.sup.3 is alkyl and q is from 0 to 4. The present invention is also directed to a method of preparing a phenol-functional organosilicon compound, said method comprising the steps of: (A) reacting an aliphatically unsaturated SiH-functional organosilicon compound in the presence of a hydrosilylation catalyst to form an addition reaction product, wherein the SiH-functional organosilicon compound has the formula: ##STR5## wherein each R is independently a monovalent hydrocarbon group free of aliphatic unsaturation, R.sup.2 is an aliphatically unsaturated monovalent hydrocarbon group, R.sup.3 is alkyl, p is 0 or 1, and q is from 0 to 4; and (B) reacting the addition reaction product with an alcohol or water to produce a phenol-functional organosilicon compound, wherein the alcohol has the formula A(OH).sub.n wherein A is hydrogen or a residue afforded by the removal of n hydroxyl groups from an m-valent alcohol and m and n are natural numbers wherein m.gtoreq.n. The phenol-functional organosilicon compounds of this invention contain both a phenol group and an alkoxysilyl, alkenyl, or silanol group in the same molecule. As a result, curable silicone compositions containing these phenol-functional organosilicon compound have excellent adhesion to glasses, organic resins such as phenolic resins and epoxy resins, and metals such as copper, aluminum, and stainless steel. The method of this invention is a highly productive method for producing the novel phenol-functional organosilicon compound. The phenol-functional organosilicon compound of this invention can be used as adhesion promoters in curable silicone compositions. In particular the phenol-functional organosilicon compound of the instant invention is highly suitable for use as an adhesion promoter in addition reaction-curing silicone compositions. The phenol-functional organosilicon compound of this invention can also be used as an optical matching oil and as a polymerization terminator. DETAILED DESCRIPTION OF THE INVENTION A phenol-functional organosilicon compound according to the present invention has the formula: ##STR6## wherein A is hydrogen or a residue afforded by the removal of n hydroxyl groups from an m-valent alcohol, each R is independently a monovalent hydrocarbon group free of aliphatic unsaturation, each R.sup.1 is independently a divalent hydrocarbon group containing at least 2 carbon atoms, m and n are natural numbers wherein m.gtoreq.n, p is 0 or 1, and Y is a phenol group having the formula: ##STR7## wherein R.sup.3 is alkyl and q is from 0 to 4. In the formula of the phenol-functional organosilicon compound of the present invention, the subscripts m and n are typically in the range from 1 to 5, and m must be greater than or equal to n. Examples of alcohol-derived residues represented by A include, but are not limited to, the following monovalent, divalent, and trivalent groups: unsubstituted hydrocarbyl, alkyloxyalkylene, alkenyloxyalkylene, phenyloxyalkylene, hydroxy-functional hydrocarbyl, hydroxy-functional alkyloxyalkylene, and hydroxy-functional alkenyloxyalkylene. The following are examples of residues afforded by removal of the hydroxyl group from a monovalent alcohol: methyl, ethyl, propyl, butyl, hexyl, allyl, butenyl, hexenyl, and propylene oxide. Residues afforded by the removal of 1 hydroxyl group from a divalent alcohol are exemplified by 2-hydroxyethyl, 2-hydroxypropyl, 3-hydroxypropyl, 2-hydroxybutyl, 3-hydroxybutyl, and 3-allyloxy-2-hydroxypropyl. Residues afforded by the removal of 2 hydroxyl groups from a divalent alcohol are exemplified by ethylene, propylene, butylene, hexylene, and ethyleneoxypropylene. Residues afforded by the removal of 1 hydroxyl group from a trivalent alcohol are exemplified by dihydroxypropyl, dihydroxybutyl, and dihydroxyhexyl. Residues afforded by the removal of 2 hydroxyl groups from a trivalent alcohol are exemplified by hydroxypropylene, hydroxybutylene, and hydroxyhexylene. Preferred embodiments of the group A are as follows: the hydrogen atom; alkyl such as methyl and ethyl and aliphatically unsaturated groups such as allyl, butenyl, and hexenyl among the residues afforded by removal of the hydroxyl group from a monovalent alcohol; and hydroxyl-functional alkenyloxyalkylene groups such as 3-allyloxy-2-hydroxypropyl among the residues afforded by removal of1 hydroxyl group from a divalent alcohol. Aliphatically unsaturated groups are particularly preferred from the perspective of their adhesion-promoting performance. Examples of the monovalent hydrocarbon groups represented by R include, but not limited to, alkyl such as methyl, ethyl, butyl, pentyl, and hexyl; aryl such as phenyl, tolyl, and xylyl; and aralkyl such as benzyl and phenethyl. Examples of the divalent hydrocarbon groups represented by R.sup.1 include, but not limited to, alkylene groups such as ethylene, propylene, butylene, and hexylene and by arylene groups such as phenylene. In the phenol group represented by Y, the bonding positions of the hydroxyl and alkoxy are not critical. Examples of phenol groups include, but are not limited to, 2-hydroxyphenyl, 4-hydroxyphenyl, 4-hydroxy-3-methoxyphenyl, and 3,5-dimethoxy-4-hydroxyphenyl. Preferably, Y is 2-hydroxyphenyl or 4-hydroxy-3-methoxyphenyl, based on availability. The subscript q is typically 0 or 1. Examples of alkyl groups represented by R.sup.3 in the formula of the phenol group include, but are not limited to, methyl, ethyl, propyl, and butyl with methyl being specifically preferred. Examples of the phenol-functional organosilicon compounds of this invention include, but are not limited to, the following silanes: ##STR8## ##STR9## The phenol-functional organosilicon compounds of this invention can be synthesized, for example, by an intramolecular or intermolecular addition reaction of an aliphatically unsaturated SiH-functional organosilicon compound in the presence of a hydrosilylation catalyst. In particular, a method of preparing a phenol-functional organosilicon compound according to the present invention comprises the steps of: (A) reacting an aliphatically unsaturated SiH-functional organosilicon compound in the presence of a hydrosilylation catalyst to form an addition reaction product, wherein the SiH-functional organosilicon compound has the formula: ##STR10## wherein each R is independently a monovalent hydrocarbon group free of aliphatic unsaturation, R.sup.2 is an aliphatically unsaturated monovalent hydrocarbon group, R.sup.3 is alkyl, p is 0 or 1, and q is from 0 to 4; and (B) reacting the addition reaction product with an alcohol or water to produce a phenol-functional organosilicon compound, wherein the alcohol has the formula A(OH).sub.n wherein A is hydrogen or a residue afforded by the removal of n hydroxyl groups from an m-valent alcohol and m and n are natural numbers wherein m.gtoreq.n. Examples of aliphatically unsaturated monovalent hydrocarbon groups represented by R.sup.2 in the preceding formula include, but are not limited to, vinyl, allyl, butenyl, and hexenyl. Allyl is preferred based on cost and availability. Preferred SiH-functional organosilicon compounds are the dimethylsilyl ether of 2-allylphenol and the dimethylsilyl ether of eugenol. A, R, R.sup.3, m, n, p, and q are as defined and exemplified above for the phenol-functional organosilicon compound of the present invention. The hydrosilylation catalyst of the present method can be, for example, a catalytic complex of a transition metal from Group 8 of the Periodic Table. Platinum-based catalysts are particularly effective within this group of catalysts and are specifically exemplified by platinum compounds such as chloroplatinic acid and its alcohol solutions, olefin complexes of platinum, and platinum/vinyl-functional siloxane complexes. These catalysts are used in sufficient quantity to give 0.001 to 10,000 and more preferably 0.1 to 100 weight parts platinum metal for each one million weight parts of the SiH-functional organosilicon compound and the alcohol or water combined. Examples of alcohols suitable for use in the present method include, but re not limited to, allyl alcohol, glycerol .alpha.-monoallyl ether, methanol, ethanol, propanol, and ethylene glycol. The alcohol or water used in step (B) of the present method is used in sufficient quantity such that the ratio of the number of equivalents of OH in the alcohol or water per equivalent of silyl phenyl ether group in the SiH-functional organosilicon compound is at least 1.0, preferably from 1.0 to 50, and more preferably from 1.5 to 10. Since the intramolecular and intermolecular addition reactions of the SiH-functional organosilicon compound are exothermal, in order to prevent sudden heating the method of the present invention is preferably carried out by first mixing the hydrosilylation catalyst with a solvent to form a mixture and then gradually adding the SiH-functional organosilicon compound dropwise to the mixture. Solvents usable for this purpose are exemplified by aromatic solvents such as benzene, toluene, and xylene; aliphatic solvents such as pentane, hexane, heptane, octane, and decane; ethers such as tetrahydrofuran, diethyl ether, and dibutyl ether; ketones such as acetone and methyl ethyl ketone; esters such as ethyl acetate and butyl acetate; and chlorinated hydrocarbons such as carbon tetrachloride, trichloroethane, methylene dichloride, and chloroform. The reaction can be run at room temperature, but in general it is preferable, from the standpoint of the reaction rate, to run the reaction at from 50 to 200.degree. C. During the course of the reaction, the reaction mixture can be analyzed, for example, by gas chromatography (GLC) or infrared spectroscopic analysis (IR) and the reaction can be considered as complete when, for example, the absorption characteristic of the silicon-bonded hydrogen in the SiH-functional organosilicon compound has more or less completely disappeared. The water or alcohol is then added to the resulting addition reaction product, resulting in a desilylation reaction. Although the desilylation reaction can be carried out using methods known in the art, alcohol exchange by heating in the presence of a basic catalyst, e.g., an amine, etc., will produce the desired organosilicon compound in high yields without the occurrence of side reactions (Japanese Patent Application Number Hei 10-259258 (259,258/1998)). After completion of the desilylation reaction, the phenol-functional organosilicon compound of this invention can be recovered by removal of low boiling materials such as unreacted water or alcohol and solvent by, for example, distillation by heating at reduced pressure. It is preferable to purify the resulting organosilicon compound by distillation. The phenol group present within the phenol-functional organosilicon compounds of this invention reacts readily with a variety of functional groups. As a consequence, when an organosilicon compound of this invention is blended into a curable silicone composition and the composition is applied to a substrate and cured, the cured silicone strongly adheres to the substrate. This applies to a variety of substrates, for example, organic resins such as phenolic resins, epoxy resins, polybutylene terephthalate resins, and polycarbonate resins; metals such as copper, aluminum, and stainless steel; glasses; etc. The cured silicone also strongly adheres to thermosetting resins such as phenolic resins and epoxy resins. The phenol-functional organosilicon compounds of this invention contain both a phenol group and an alkoxysilyl, alkenyl, or silanol group in the same molecule. As a result, curable silicone compositions containing these phenol-functional organosilicon compounds have excellent adhesion to glasses, organic resins such as phenolic resins and epoxy resins, and metals such as copper, aluminum, and stainless steel. The method of this invention is a highly productive method for producing the novel phenol-functional organosilicon compounds. The phenol-functional organosilicon compounds of this invention can be used as adhesion promoters in curable silicone compositions. In particular the phenol-functional organosilicon compounds of the instant invention are highly suitable for use as adhesion promoters in addition reaction-curing silicone compositions. The phenol-functional organosilicon compounds of this invention can also be used as optical matching oil and as polymerization terminator. |
| PATENT EXAMPLES | This data is not available for free |
| PATENT PHOTOCOPY | Available on request |
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