Organopolysiloxanes and methods of making

Abstract: Organopolysiloxanes having two different functional groups selected from the group consisting of 3-glycidoxy-propyl, 2-(3′,4′-epoxycyclohexyl)ethyl, 3-hydroxypropyl, 3-(2′-hydroxyethoxy)propyl, 3-acryloxypropyl, and 3-methacryloxypropyl groups are more compatible with organic resins and more effective for tailoring the organic resins. They are produced by hydrosilylation of organohydrogenpolysiloxanes with functional group-containing alkenes.

Description: This invention relates to organopolysiloxanes and methods for preparing the same. More particularly, it relates to novel organopolysiloxanes having organic functional groups suitable for use as modifiers of organic resins in paint, molding material, medical material, and coating material applications. BACKGROUND OF THE INVENTION From the past, organopolysiloxanes having an organic functional group were widely used as resin modifiers in the fields of paint, molding materials, medical materials, and coating materials for the purpose of imparting useful properties such as heat resistance, weather resistance, mold release, formability and thermal impact to organic resins. There were known various organopolysiloxanes having an organic functional group, for example, dimethylpolysiloxane having an alcoholic hydroxyl group at either end (see Japanese Patent Publication No. 8718/1979), dimethylpolysiloxane having a functional group at either end (see Japanese Patent Application Kokai Nos. 217515/1983 and 123502/1984), methylpolysiloxane having a functional group on a side chain (see Japanese Patent Publication Nos. 18960/1986 and 28880/1985), and methylphenylpolysiloxane having an alcoholic hydroxyl group at either end and on a side chain. EP-A-468305 (in Article 54(3) EPC relation to the present disclosure) describes organopolysiloxanes having methyl side groups and, to give optimal adhesive release properties, a combination of epoxy-containing side groups (which may be 3-glycidoxypropyl or 2-(3',4'-epoxycyclohexyl) -ethyl groups) with R³OH side groups in which R³ is a C₃₋₁₁ alkylene group. 3-hydroxypropyl is exemplified for the latter. EP-A-281718 describes novel processes for introducing 3-acryloxypropyl or 3-methacryloxypropyl ester groups onto a silicone chain. A complete or partial transesterification is proposed in which a group YOH (which may be 3-hydroxypropyl) is reacted with a lower alkyl (meth)acryloxy in the presence of a catalyst. Some 3-hydroxypropyl may be left unreacted, or reacted with another side-group-forming reagent. Proposed uses for the resulting organopolysiloxane oils are as an additive for silicone elastomers, and as UV-curable silicone coating compositions. US-A-4294974 describes homo-and co-polymers of siloxanes carrying hydroxymethyl and/or 3-hydroxypropyl groups together with unsaturated groups which may be methacryloxypropyl. Sufficient hydroxy groups are present to give hydrophilic properties enabling use to make contact lenses. The organopolysiloxanes having the same functional groups in their molecule possess properties corresponding to the respective functional groups. There is a need for an organopolysiloxane which is more compatible with organic resins and more effective as a resin modifier than the conventional organopolysiloxanes. The inventors have discovered that by sequentially effecting consecutive addition reaction of two unsaturated compounds selected from the group consisting of allyl glycidyl ether, 1-vinyl- 3,4-epoxycyclohexane, allyl glycol, allyl acrylate, and allyl methacrylate SiH of an organohydrogenpolysiloxane of the following average composition formula (3): wherein R is an alkyl group having 1 to 6 carbon atoms or phenyl group, and letters a, b and c are positive numbers within the range: 1 ≤ a ≤ 20, 1 ≤ b ≤ 10, and 1 ≤ c ≤ 10, more particularly, by adding b mol of a first unsaturated compound to SiH of an organoorganohydrogenpolysiloxaneof formula (3) and adding c mol of a second unsaturated compound to c mol of unreacted SiH of the organohydrogenpolysiloxane of formula (3), there is obtained an organopolysiloxane of the following average composition formula (1): wherein X and Y are organic groups selected from different ones of (i), (ii) and (iii) as follows: (i) 3-glycidoxypropyl,2-(3',4'-epoxycyclohexyl)-ethyl (ii) 3-(2-hydroxyethoxy)-propyl (iii) 3-hydroxypropyl, 3-methacryloxypropyl; and R, a, b and c are as defined above. The inventors have also discovered that by adding an unsaturated compound selected from the group consisting of allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, allyl glycol, allyl acrylate, and allyl methacrylate to SiH of an organohydrogenpolysiloxane of the following average composition formula (4): wherein Y, R, a and b are as defined above, the unsaturated compound forming a functional group different from Y of the organohydrogenpolysiloxane of formula (4), there is obtained an organopolysiloxane of the following average composition formula (2) : wherein X, Y, R, a, and b are as defined above. The organopolysiloxanes of formulae (1) and (2) each having two different functional groups within a molecule are highly compatible with organic resins such as epoxy resins and acrylic resins and capable of imparting desired properties such as heat resistance, weather resistance, formability, water repellency and adhesion to the resins depending on particular types of functional groups they possess. For example, polysiloxanes having both epoxy and alcoholic hydroxyl groups or both (meth)acryloxy and alcoholic hydroxyl groups are effective for modifying various organic resins through grafting, thereby improving interfacial adhesion and increasing strength by utilizing a multiplicity of available crosslinking points. In particular, since the present organopolysiloxanes each having two different functional groups which are different in reactivity can be used in such a manner that two different modes of crosslinking occur or polymerization and crosslinking occur separately, they are advantageous resin modifiers. The organopolysiloxanes of formula (2) wherein Y is 3-acryloxypropyl or 3-methacryloxypropyl group are particularly useful in that when they are subject to radical polymerization at their acryl or methacryl group or radical copolymerization at their acryl or methacryl group with other polymerizable monomers, there are obtained functional group-containing siloxane grafted acrylic polymers which were difficult to synthesize in the prior art. Moreover, the present organopolysiloxanes, when having diphenylsiloxane or methylphenylsiloxane units incorporated therein, become more compatible with organic resins. Therefore, the present invention provides organopolysiloxanes of formulae (1) and (2) as defined above. Methods for producing them are by consecutive hydrosilylation of a compound of formula (3) with two different unsaturated compounds and by hydrosilylation of a compound of formula (4) with an unsaturated compound. In order that the present invention is clearly understood, embodiments will now be described by way of example with reference to Figs. 1 to 4 which are IR absorption spectra of organopolysiloxanes of the present invention. The present invention provides organopolysiloxanes of the following average composition formulae (1) and (2). In formulae (1) and (2), X and Y are organic groups selected from different ones of (i), (ii) and (iii) as follows: (i) 3-glycidoxypropyl, 2-(3',4'-epoxycyclohexyl)-ethyl (ii) 3-(2-hydroxyethoxy)-propyl (iii) 3-acryloxypropyl, 3-methacryloxypropyl; R is an alkyl group having 1 to 6 carbon atoms or phenyl group, and letters a, b and c are positive numbers within the range: 1 ≤ a ≤ 20, 1 ≤ b ≤ 10 and 1 ≤ c ≤ 10. More particularly, R is an alkyl group having 1 to 6 carbon atoms such as methyl, ethyl and propyl groups or a phenyl group, with the methyl and phenyl groups being preferred for commercial purposes. Preferably, both methyl and phenyl groups are used together. For example, by incorporating a diphenylsiloxane or methylphenylsiloxane unit into a siloxane having a dimethylsiloxane unit in the backbone, there can be obtained an organopolysiloxane which is further improved in reactivity and compatibility with organic resins. Letters a, b, and c are within the above-defined range. As the siloxane chain becomes longer (a, b, and c in excess of their upper limit), the siloxane becomes higher in viscosity, more difficult to handle, and less compatible with organic resins. The compounds of formula (1) can be readily synthesized in high yields by incorporating different organic groups X and Y through partial hydrosilylation reaction in accordance with the following method. In the following formulae, X, Y, R, a, b, and c are as defined above. First, b mol of an unsaturated compound selected from the group consisting of allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, allyl glycol, allyl acrylate, and allyl methacrylate is added to SiH of an organohydrogenpolysiloxane of the following average composition formula (3). There is obtained an addition reaction product of the following average composition formula (3´). Alternatively, the compound of formula (3') can be separately prepared by hydrolysis or equilibration reaction. Next, c mol of another unsaturated compound selected from the same group as above is added to the compound of formula (3´) having residual SiH groups. There is obtained an organopolysiloxane of formula (1). The organohydrogenpolysiloxane of formula (3) can be readily prepared by effecting equilibration reaction among tetramethylcyclotetrasiloxane, a cyclic polysiloxane, and a disiloxane as a terminal group in the presence of sulfuric acid or a sulfonic acid. Several, non - limiting examples of the organohydrogenpolysiloxane of formula (3) are given below. In the following description, Me is methyl and Ph is phenyl. Preferably, the above - mentioned consecutive hydrosilylation reactions are carried out in the presence of a platinum catalyst. That is, an organohydrogenpoly-siloxane of formula (3) is partially hydrosilylated with a functional groupcontaining alkene or unsaturated compound in the presence of a platinum catalyst. After the consumption of the functional group-containing alkene is complete, hydrosilylation with another functional group-containing alkene is started. Any desired one of well-known platinum catalysts for hydrosilylation may be used. For commercial purposes, chloroplatinic acid is preferred in that addition reaction can be complete by heating at a temperature of about 60°C to 120°C for about 2 to 8 hours. The platinum catalyst is used in a catalytic amount, often about 2 to 400 ppm based on the weight of the organohydrogenpolysiloxane. Reaction may be carried out in suitable solvents, for example, aromatic hydrocarbon solvents such as benzene, toluene and xylene and aliphatic hydrocarbon solvents such as hexane, heptane, and octane for controlling the reaction system viscosity and reaction temperature. When it is desired to add alcoholic hydroxyl group-containing alkenes, alcoholic solvents such as ethanol, isopropyl alcohol, butanol, and isobutanol may be used to which system potassium acetate is added in an amount of about 0.001 to 0.5% by weight based on the organohydrogenpolysiloxane to complete the addition reaction quickly. In the alternative method, an organopolysiloxane of formula (1) is produced by separately preparing an organohydrogenpolysiloxane of formula (3´) through acid equilibration reaction or decomposition reaction and effecting similar addition reaction. In this embodiment, X in formula (3′) is preferably 3-acryloxypropyl or 3-methacryloxypropyl group. In another form of the invention, an organopolysiloxane of formula (2) having a terminal functional group different from a side functional group can be readily synthesized in high yields by effecting hydrosilylation reaction between a double hydrogen - terminated organopolysiloxane of average composition formula (4) and a functional group-containing alkene. In the following formulae, X, Y, R, a, b, and c are as defined above. To SiH of an organohydrogenpolysiloxane of average composition formula (4): is added an unsaturated compound selected from the group consisting of allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane, allyl glycol, allyl acrylate, and allyl methacrylate which provides a functional group different from Y of the organohydrogenpolysiloxane of formula (4). There is obtained an organopolysiloxane of formula (2). The functional group Y of the organohydrogenpolysiloxane of formula (4) should preferably be an organic group less reactive to sulfuric acid and sulfonic acids, typically acryloxypropyl and methacryloxypropyl groups. The organohydrogenpolysiloxane of formula (4) can be readily prepared by effecting equilibration reaction among a tetraalkyldisiloxane, a hydrolysate of a dialkoxysilane containing a functional group Y, and a cyclic polysiloxane in the presence of sulfuric acid or a sulfonic acid. Several, non-limiting examples of the organohydrogenpolysiloxane of formula (4) are given below. In the following formulae, Y´ is a 3-acryloxypropyl or 3-methacryloxypropyl group. The hydrosilylation reaction between an organohydrogenpolysiloxane of formula (4) and a functional group-containing alkene may be carried out as in the above-mentioned hydrosilylation reaction to produce an organopolysiloxane of formula (1). There have been described organopolysiloxanes having different functional groups in a molecule which are highly compatible with organic resins and, when added to organic resins as a silicone resin modifier, can impart to the resins heat resistance, weather resistance, formability, water repellency, adhesion or any other desired properties attributable to the functional groups. The manufacturing methods of the present invention permit for easy synthesis of such organopolysiloxanes having different functional groups in high yields. EXAMPLE Examples of the present invention are given below by way of illustration. Example 1 A flask was charged with 40 grams of toluene, 9.6 grams of allyl methacrylate, and 0.1 gram of 2% ethanol solution of chloroplatinic acid. To the flask at 80°C, 100 grams of hydrogenpolysiloxane of the following average composition formula: was added dropwise over 2 hours. After the completion of addition, the reaction mixture was aged for one hour at 80°C. After the disappearance of the absorption peak (1650 cm⁻¹) attributable to the allyl group of allyl methacrylate was confirmed by an IR spectrometer, the reaction mixture was cooled to room temperature. Next, a separate flask was charged with 60 grams of toluene, 61.8 grams of allyl glycol, and 0.2 gram of 2% ethanol solution of chloroplatinic acid. To the flask at 80°C, the entire reaction mixture (toluene solution of an addition product, hydrogenpolysiloxane having allyl methacrylate added thereto) was added dropwise over 2 hours. After the completion of addition, the reaction mixture was aged for 2 hours at 80°C. The disappearance of the Si-H absorption peak (2160 cm⁻¹) was confirmed by an IR spectrometer. After removal of the toluene and unreacted reactants by vacuum distillation and filtration, there was isolated 161.8 grams (yield 96%) of an addition product. Measurement of physical properties identified this product to have the following average composition formula. Viscosity: 715 cs at 25°C Refractive index: 1.4894 at 25°C H¹-NMR (δ, acetone δ = 2.0 standard, same in the following examples): 0.07 (38.1H) 1.50 (12H) 1.54 (12H) 3.47 (33.2H) 5.43 (0.7H) 6.00 (0.7H) 7.31 (20 H) Elemental analysis : Found: C 52.9% H 7.8% Calcd.: C 52.3% H 7.9% Infrared absorption spectrum: FIG. 1 Example 2 Two stages of addition reaction were carried out by the same procedure as in Example 1 except that a flask was first charged with 50 grams of toluene, 16.1 grams of allyl glycidyl ether, and 0.1 gram of 2% ethanol solution of chloroplatinic acid. There was obtained 161.6 grams (yield 98%) of a corresponding addition product. Measurement of physical properties identified this product to have the following average composition formula. Viscosity: 1530 cs at 25°C Refractive index: 1.4960 at 25°C H¹-NMR ( δ ): 0.07 (36H) 0.48 (12H) 1.55 (12H) 2.43 (1.3H) 2.60 (1.3H) 3.42 (34.7H) 7.35 (20H) Elemental analysis : Found: C 52.5% H 7.7% Calcd.: C 52.5% H 7.9% Infrared absorption spectrum: FIG. 2 Example 3 A flask was charged with 100 grams of toluene, 19.7 grams of allyl glycol, and 0.2 gram of 2% ethanol solution of chloroplatinic acid. To the flask at 80°C, 100 grams of hydrogenpolysiloxane of the following average composition formula: was added dropwise over 2 hours. After the completion of addition, the reaction mixture was aged for 2 hours at 80°C. After the disappearance of the Si-H absorption peak (2130 cm⁻¹) was confirmed by an IR spectrometer, the toluene and unreacted reactants were removed by vacuum distillation and filtration, isolating 116.4 grams (yield 98%) of an addition product which was identified to have the following average composition formula. Viscosity: 195 cs at 25°C Refractive index: 1.4876 at 25°C H¹- NMR (δ): 0.04 (48H) 0.47 (6H) 1.54 (6H) 3.43 (14H) 5.40 (1H) 5.98 (1H) 7.27 (20H) Elemental analysis: Found: C 52.2% H 7.5% Calcd.: C 52.1% H 7.6% Infrared absorption spectrum: FIG. 3 Example 4 The procedure of Example 3 was repeated except that 22.0 grams of allyl glycidyl ether was used instead of 19.7 grams of allyl glycol, isolating 119.8 grams (yield 99%) of a corresponding addition product which was identified to have the following average composition formula. Viscosity: 450 cs at 25°C Refractive index: 1.4846 at 25°C H¹-NMR ( δ ): 0.07 (48H) 0.48 (6H) 1.57 (6H) 2.38 (2H) 2.54 (2H) 3.33 (2H) 5.37 (1H) 5.97 (1H) 7.22 (20H) Elemental analysis: Found: C 53.1% H 7.3% Calcd.: C 52.9% H 7.5% Infrared absorption spectrum: FIG. 4 Although some preferred embodiments have been described, many modifications and variations may be made thereto in the light of the above teachings. It is therefore to be understood that within the scope of the appended claims, the invention may be practiced otherwise than as specifically described.

Claims: An organopolysiloxane of the formula (1): in which: groups R are C₁₋₆ alkyl or phenyl; X and Y are organic groups selected from different ones of (i), (ii) and (iii) as follows: (i) 3-glycidoxypropyl, 2-(3',4'-epoxycyclohexyl)-ethyl (ii) 3-(2-hydroxyethoxy)-propyl (iii) 3-acryloxypropyl, 3-methacryloxypropyl; 1≤a≤20, 1≤b≤10 and 1≤c≤10.. An organopolysiloxane of the formula (2): in which: groups R are C₁₋₆ alkyl or phenyl; X and Y are organic groups selected from different ones of (i), (ii) and (iii) as follows: (i) 3-glycidoxypropyl, 2-(3',4'-epoxycyclohexyl)-ethyl (ii) 3-(2-hydroxyethoxy)-propyl (iii) 3-acryloxypropyl, 3-methacryloxypropyl; 1≤a≤20 and 1≤b≤10. An organopolysiloxane according to claim 1 or claim 2 in which X and Y are selected from (i) and (ii). An organopolysiloxane according to claim 1 or claim 2 in which X and Y are selected from (ii) and (iii). An organopolysiloxane according to claim 2 in which Y is 3-acryloxypropyl or 3-methacryloxypropyl. An organopolysiloxane according to any one of the preceding claims in which groups R include both methyl and phenyl groups. An method of making an organopolysiloxane according to claim 1 or any one of claims 3, 4, and 6 as dependent on claim 1, comprising: reacting b mol of an unsaturated compound selected from any one of (i), (ii) and (iii) as follows: (i) allyl glycidyl ether, 1-vinyl-3,4- epoxycyclohexane (ii) allyl glycol (iii) allyl acrylate, allyl methacrylate with the SiH of organohydrogenpolysiloxane of the formula (3) : (in which R, a, b and c are as defined in claim 1 or said claim dependent thereon), and reacting c mol of another unsaturated compound selected from a different one of (i), (ii) and (iii) with residual unreacted SiH of the organohydrogenpolysiloxane of formula (3). A method of making an organopolysiloxane according to claim 1 or any one of claims 3, 4 and 6 as dependent thereon, comprising: reacting an unsaturated compound selected from one of (i), (ii) and (iii) as follows: (i) allyl glycidyl ether, 1-vinyl-3,4- epoxycyclohexane (ii) allyl glycol (iii) allyl acrylate, allyl methacrylate with the SiH of organohydrogenpolysiloxane of the formula (3´): (in which X, R, a, b and c are as defined in claim 1 or said claim dependent thereon), the unsaturated compound being from one of (i), (ii) and (iii) different from that containing the unsaturated compound which would give X on reaction with SiH. A method of making an organopolysiloxane according to claim 2 or any one of claims 3 to 6 as dependent on claim 2, comprising: reacting an unsaturated compound selected from one of (i), (ii) and (iii) as follows: (i) allyl glycidyl ether, 1-vinyl-3,4-epoxycyclohexane (ii) allyl glycol (iii) allyl acrylate, allyl methacrylate with the SiH of organohydrogenpolysiloxane of the formula (4): (in which Y, R, a, b and c are as defined in claim 1 or said claim dependent thereon), the unsaturated compound being from one of (i), (ii) and (iii) different from that containing the unsaturated compound which would give Y on reaction with SiH. Use of an organopolysiloxane according to any one of claims 1 to 6 by blending it with a compatible organic resin to modify the properties at the compatible organic resin. Use according to claim 10 in which the compatible organic resin is an acrylic or epoxy resin.

Inventors: ISOBE KENICHI, TAKARADA MITSUHIRO, YOSHIKAWA YUJI, ISOBE, KENICHI, TAKARADA, MITSUHIRO, YOSHIKAWA, YUJI
Applicants: SHINETSU CHEMICAL CO, SHIN-ETSU CHEMICAL CO., LTD.
Application year: 1991
Main classification: C08G77
IPC codes: C08G77