JP2585099B2 - Method for producing α, ω-dihydrogen organopolysiloxane - Google Patents

Description

The present invention relates to a method for producing an α, ω-dihydrogen organopolysiloxane, and more particularly, to a method wherein the siloxane units have no distribution and a constant siloxane chain length. The present invention relates to a method for producing an α, ω-dihydrogen organopolysiloxane.

[Conventional technology and its problems]

Α, ω having Si-H groups at both ends of polysiloxane chain
-Dihydrogen organopolysiloxane is used in a wide range of industrial fields as a raw material of silicone rubber, modified silicone or a surface treating agent. Conventionally,
Examples of the method for producing α, ω-dihydrogen organopolysiloxane include (1) a method of ring-opening polymerization of tetramethyldisiloxane and octamethylcyclotetrasiloxane, and (2) a method of hydrolyzing α, ω-dialkyldichlorosilane. -A method of obtaining dichloroorganopolysiloxane and reducing it with lithium aluminum hydride [Polish Journal of Chemistry (Polish Jou
rnal of Chemistry), 53, 6 p. 1363, 1979
And (3) a method of obtaining the compound by heterogeneous tetramethyldisiloxane and chlorosilane [West German Patent No. 2630744
No.] is known.

However, since all of these methods basically use an equilibration reaction, distribution occurs in siloxane units of a product, and a product having a specific chain length cannot be produced with high yield. Had the problem that

[Means for solving the problem]

Under such circumstances, the present inventors have conducted various studies to solve the above problems, and as a result, if a specific cyclic silicone, chlorosilane and water are reacted in the presence of an inorganic solid compound, the starting cyclic silicone can be obtained. The inventors have found that an α, ω-dihydrogen organopolysiloxane having a corresponding constant chain length and having no distribution of siloxane units can be obtained with high selectivity, and completed the present invention.

That is, the present invention relates to the following general formula (II) (R ¹ R ² SiO) _n (II) wherein R ¹ and R ² may be the same or different, and may be a hydrogen atom, an alkyl group, an alkenyl group, an aryl A cyclic silicone represented by the following general formula (III): R ¹ R ² SiHCl (III) wherein R ¹ and R ² are Chlorosilane and water represented by the following general formula (I): HR ¹ R ² SiO (R ¹ R ² SiO) _n SiR ¹ R ² H (I) wherein R ¹ , R ² and n have the same meanings as described above. The present invention provides a method for producing an α, ω-dihydrogen organopolysiloxane represented by the formula:

The reaction in the production method of the present invention is basically a two-phase reaction between a phase composed of cyclic silicone (II) and chlorosilane (III) and an aqueous phase, and proceeds according to the following reaction formula using an inorganic solid compound as a catalyst. it is conceivable that.

(IV) + (V) → HR ¹ R ² SiO (R ¹ R ² SiO) _n SiR ¹ R ² H (3) That is, chlorosilane (III) is hydrolyzed first, and the corresponding silanol (IV) and hydrogen chloride (Reaction formula (1)). By the catalytic action of the hydrogen chloride, the cyclic silicone (II) and the chlorosilane (III) react to form an α-chloro ω-hydrogen organopolysiloxane (V).
(Reaction formula (2)). Next, the α-chloroω-hydrogenorganopolysiloxane (V) undergoes a dehydrochlorination reaction with the silanol (IV) to give α, ω-dihydrogenorganopolysiloxane (reaction formula (3)).

In the production method of the present invention, the cyclic silicone (II) which is a starting material for producing the α, ω-dihydrogen organopolysiloxane (I) includes, for example, hexamethylcyclotrisiloxane, hexaethylcyclotrisiloxane, hexaphenyl Cyclotrisiloxane, trimethyltrivinylcyclotrisiloxane, trimethyltriphenylcyclotrisiloxane, octamethylcyclotetrasiloxane, octaethylcyclotetrasiloxane,
Examples include octaphenylcyclotetrasiloxane, tetramethyltetraphenylcyclotetrasiloxane, tetramethyltetravinylcyclotetrasiloxane, tetra (trifluoropropyl) tetramethylcyclotetrasiloxane, decamethylcyclopentanesiloxane, dodecamethylcyclohexasiloxane, and the like.

Examples of the other material, chlorosilane (III), include dimethylchlorosilane, diethylchlorosilane, diphenylchlorosilane, divinylchlorosilane, and the like.

Further, as the inorganic solid compound used as a catalyst in the production method of the present invention, those which are insoluble and uniformly dispersed in the reaction solution are preferable, and examples thereof include silica gel, titanium dioxide, and silica / alumina. Of these, silica gel is particularly preferably used. Here, silica gel refers to an amorphous silicic acid polymer. In the present invention, any type can be used. However, those having a small particle size are preferable because the reaction rate can be increased with a small amount of use.

In order to produce the α, ω-dihydrogen organopolysiloxane (I) by the production method of the present invention, the above-mentioned chlorosilane (III) is added to a mixture of the above-mentioned cyclic silicone (II), inorganic solid compound and water. preferable.

The amount of the chlorosilane (III) used in the reaction is 2 to 10 times the molar amount of the cyclic silicone (II),
The molar amount is preferably twice as much, especially about three times as much.

The amount of the inorganic solid compound used is appropriately selected depending on the reactivity of the cyclic silicone (II) and chlorosilane (III), but is preferably in the range of 1 to 50% by weight based on the cyclic silicone (II).

Water is in principle used in stoichiometric excess. That is, 1 to 500 times the molar amount of the cyclic silicone (II),
Preferably, it is used in a range of 5 to 20 times mol.

The reaction solution may or may not be used, but when hexamethylcyclotrisiloxane which is a solid at room temperature is used as the cyclic silicone, it may be used to facilitate the reaction. Examples of the solvent to be used include hydrocarbon solvents that do not mix with water, such as pentane, hexane, heptane, benzene, and toluene.

The reaction in the production method of the present invention is the reaction of a cyclic silicone (II)
Chlorosilane (II
I) After the addition, the reaction is completed in 1 to 5 hours at room temperature. By distilling the obtained reaction solution under normal pressure, preferably under reduced pressure, mixed unreacted cyclic silicone and chlorosilane can be easily separated, and α, ω-dihydrogen organopolysiloxane can be obtained. The cyclic silicone and chlorosilane recovered here can be reused in the reaction of the present invention.

〔Example〕

Hereinafter, the present invention will be described in more detail with reference to Examples.
The present invention is not limited to these examples.

Example 1 Synthesis of 1,9-dihydrogendecamethylpentasiloxane [In the general formula (I), R ¹ = R ² = CH ₃ , n = 3]: Hexamethylcyclotrimethyl was added to a flask equipped with a dropping funnel. Siloxane 100g, Hexane 100g, Water 81g, Silica gel (Merck Kieselgel 60, 250-400 mesh)
Charge 5.0g. While sufficiently stirring, 127.7 g of dimethylchlorosilane is added dropwise over 30 minutes. After 30 minutes, the flask is returned to room temperature and stirring is continued. After one hour, stop stirring and filter the Kieselgel. The resulting filtrate is distilled to remove excess dimethylchlorosilane. The obtained solution is transferred to a separating funnel and separated twice with 200 ml of water and twice with 200 ml of a saturated aqueous sodium hydrogen carbonate solution and further with 200 ml of water. After completely removing water in the solution by azeotropic distillation with benzene, distillation under reduced pressure gives 137.3 g (yield 85.5%) of 1,9-dihydrogendecamethylpentasiloxane. All of the starting hexamethylcyclotrisiloxane had reacted.

bp 57 ° C / 0.5 mmHg MS 355 (M ⁺ -1), 341 (M ⁺ -15) IR 2188 cm ^-1 (Si-H) ²⁹ Si-NMR; ppm (δ) (in heavy benzene, based on TMS)-6.73 (1 and 9-Si) -19.78 (3 and 7-Si) -21.57 (5-Si) ¹ H-NMR; ppm (δ) (in heavy benzene, C ₆ H ₆ , δ = 7.15) 0.16 (18H , s) 0.18 (12H, d, 3 Hz) 4.96 to 5.00 (2H, bs) Example 2 Synthesis of 1,11-dihydrogendecamethylhexylsiloxane [In the general formula (I), R ¹ = R ² = CH ₃ , n = 4]: 500 g of octamethylcyclotetrasiloxane, 304.2 g of water, and 50.5 g of silica gel (Kieselgel 60, 250-400 mesh, manufactured by Merck) are charged into a two flask equipped with a dropping funnel. Dimethylchlorosilane with sufficient stirring
479.6 g is added dropwise over 30 minutes. After 30 minutes, the flask is returned to room temperature and stirring is continued. After 4 hours, stop stirring and filter the Kieselgel. The resulting filtrate is distilled to remove excess dimethylchlorosilane. The obtained solution is transferred to a separating funnel and separated twice with 500 ml of water and twice with 500 ml of a saturated aqueous sodium hydrogen carbonate solution and further with 500 ml of water. After water in the solution was completely removed by azeotropic distillation with benzene, distillation under reduced pressure gave 1,11-dihydrogen decamethylhexane as 34%.
1 g (47% yield) is obtained. 198.5 g (39.7%) of octamethylcyclotetrasiloxane as a raw material was recovered. The yield calculated based on the reacted octamethylcyclotetrasiloxane is 78%.

bp 81 ° C / 0.16 mmHg MS 429 (M ⁺ -1), 415 (M ⁺ -15) IR 2128 cm ^-1 (Si-H) ²⁹ Si-NMR; ppm (δ) (in heavy benzene, based on TMS)-6.74 (1 and 11-Si) -19.81 (3 and 9-Si) -21.62 (5 and 7-Si) ¹ H-NMR; ppm (δ) (in heavy benzene, C ₆ H ₆ , δ = 7.15) 0.18 (12H, s) 0.19 (12H, d, 2.7Hz) 0.21 (12H, s) 5.00 (2H, Sept, 2.7Hz) Example 3 Synthesis of 1.13-dihydrogentetradecamethylheptasiloxane [general formula (I) Where R ¹ = R ² = CH ₃ , n =
5]: A 200 ml flask equipped with a dropping funnel is charged with 92.5 g of decamethylcyclopentasiloxane, 13.5 g of water, and 15 g of silica gel (Kieselgel 60, 250-400 mesh, manufactured by Merck). Dimethyl chlorosilane 7 with sufficient stirring
0.9 g is added dropwise over 30 minutes. After 30 minutes, the flask is returned to room temperature and stirring is continued. After 1.5 hours, stop stirring and filter the Kieselgel. The resulting filtrate is distilled to remove excess dimethylchlorosilane. The resulting solution is transferred to a separatory funnel and separated twice with 100 ml of water and twice with 100 ml of a saturated aqueous sodium hydrogen carbonate solution and further with 100 ml of water. After completely removing water in the solution by azeotropic distillation with benzene, distillation under reduced pressure yields 38.3 g (yield 30%) of 1,13-dihydrogentetradecamethylheptasiloxane. 31.3 g (33.7%) of the starting material decamethylcyclopentasiloxane was recovered. The yield calculated based on the reacted decamethylcyclopentasiloxane is 45.2%.

bp 107 ° C / 2.0 mmHg MS 489 (M ⁺ -15) IR 2128 cm ^-1 (Si-H) ²⁹ Si-NMR; ppm (δ) (in heavy benzene, based on TMS)-6.75 (1 and 13-Si)- 19.83 (3 and 11-Si) -21.64 (5.7 and 7-Si) ¹ H-NMR; ppm (δ) (in heavy benzene, based on TMS) 0.16 (12H, s) 0.19 (12H, d, 2.7 Hz) 0.20 (12H, s) 0.21 (6H, s) 4.96 (2H, Sept, 2.7Hz) Example 4 Synthesis of 1,15-dihydrogenhexadecamethyloctasiloxane [In the general formula (I), R ¹ = R ² = CH _3, n =
6]: 300 g of dodecamethylcyclohexasiloxane, 122.4 g of water, and 30 g of silica gel (Kieselgel 60, 250-400 mesh, manufactured by Merck) are charged into two flasks equipped with a dropping funnel. With sufficient stirring, dimethylchlorosilane 19
3 g are added dropwise over 30 minutes. After 30 minutes, the flask is returned to room temperature and stirring is continued. After 4 hours, stop stirring and filter the Kieselgel. The resulting filtrate is distilled to remove excess dimethylchlorosilane. The resulting solution was transferred to a separatory funnel and washed twice with 200 ml of water, 200 ml of a saturated aqueous solution of sodium hydrogen carbonate.
Separate twice with 200 ml of water and 200 ml of water. After completely removing water in the solution by azeotropic distillation with benzene, distillation under reduced pressure
128 g (32.8% yield) of 1,15-dihydrogenhexadecamethyloctasiloxane are obtained. 153.4 g (51.1%) of dodecamethylcyclohexasiloxane as a raw material was recovered. The yield calculated based on the reacted dodecamethylcyclohexasiloxane is 67%.

bp 105 ° C / 0.14 mmHg MS 563 (M ⁺ -15) IR 2132 cm ^-1 (Si-H) ²⁹ Si-NMR; ppm (δ) (in heavy benzene, based on TMS)-6.68 (1 and 15-Si)- 19.76 (3 and 13-Si) -21.58 (5 and 11-Si) -21.60 (7 and 9-Si) ¹ H-NMR; ppm (δ) (in C ₆ H ₆ , δ = 7.15 in heavy benzene) 0.17 (12H, s) 0.19 (12H, d, 2.8Hz) 0.21 (12H, s) 0.22 (12H, s) 4.97 (2H, Sept, 2.8Hz) [Effect of the Invention] α obtained by the production method of the present invention , Ω-dihydrogen organopolysiloxane has no distribution of siloxane units, has a constant chain length, and has completely different physical properties from the mixture obtained by the conventional production method.

Claims (2)

(57) [Claims] 1. A compound represented by the following general formula (II): (R ¹ R ² SiO) _n (II) wherein R ¹ and R ² may be the same or different and are a hydrogen atom, an alkyl group, an alkenyl group, an aryl A cyclic silicone represented by the following general formula (III): R ¹ R ² SiHCl (III) wherein R ¹ and R ² are Chlorosilane and water represented by the following general formula (I): HR ¹ R ² SiO (R ¹ R ² SiO) _n SiR ¹ A process for producing an α, ω-dihydrogen organopolysiloxane represented by R ² H (I) wherein R ¹ , R ² and n have the same meaning as described above. 2. The method for producing an α, ω-dihydrogen organopolysiloxane according to claim 1, wherein the inorganic solid compound is silica gel.