Siloxane composition and method for producing same

Abstract

Provided are a siloxane composition, said siloxane composition showing physical properties between a dimethyl polysiloxane oil and a gelatinous crosslinked siloxane and being fluid or becoming fluid when dissolved in a solvent, and a method for producing the same. The siloxane composition, which is obtained by subjecting specific starting organopolysiloxane materials to an addition reaction in a large excess (i.e., 8 times by mass or greater as much as the starting materials) of a solvent, comprises a crosslinked organopolysiloxane, said crosslinked organopolysiloxane having a weight-average molecular weight of 5,000-300,000,000 and containing 0.1-50 mol of silethylene bond per 1,000 mol of siloxane unit, dissolved in the solvent.

Claims

1. A siloxane composition comprising a crosslinked organopolysiloxane dissolved in a solvent, which crosslinked organopolysiloxane has a weight-average molecular weight of 5,000 to 300,000,000, contains 6.5 to 50 moles of silalkylene linkages per 1,000 moles of siloxane units, and is obtained by hydrosilylation of an organopolysiloxane having a structure of formula (1) below with an organohydrogenpolysiloxane having a structure of formula (2) below
M.sub.M.sup.Vi.sub.D.sub.D.sup.Vi.sub.T.sub.T.sup.Vi.sub.Q.sub.(1)
M.sub.M.sup.H.sub..Math.D.sub.D.sup.H.sub.T.sub.T.sup.H.sub.(2) (wherein M is R.sub.3SiO.sub.1/2, M.sup.Vi is R.sub.2PSiO.sub.1/2, D is R.sub.2SiO.sub.2/2, D.sup.Vi is RPSiO.sub.2/2, T is RSiO.sub.3/2, T.sup.Vi is PSiO.sub.3/2, M.sup.H is R.sub.2HSiO.sub.1/2, D.sup.H is RHSiO.sub.2/2, T.sup.H is HSiO.sub.3/2 and Q is SiO.sub.4/2, each R being independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms that has no aliphatic unsaturated bonds and P being an alkenyl group represented by (CH.sub.2).sub.aCHCH.sub.2 (where a is 0 or an integer from 1 to 6); and , , , , , , , , .Math., , , and are each independently 0 or a positive number, with the provisos that , and are not all 0, ++2, .Math., and are not all 0, and .Math.++2) in an amount of solvent that is at least 8 times the combined weight of the polysiloxanes of formulas (1) and (2) and using a platinum group metal compound, wherein the solvent comprises an organic solvent selected from among toluene, hexane, xylene and methyl ethyl ketone.

2. The siloxane composition of claim 1 wherein, in formula (1), 1+++1,000 and, in formula (2), 1++200.

3. The siloxane composition of claim 2 wherein, in formula (1), 11,000 and, in formula (2), 1200.

4. The siloxane composition of claim 1, further comprises an organopolysiloxane of formula (3) below
M.sub.,M.sup.Vi.sub.,D.sub.,D.sup.Vi.sub.67 ,T.sub.,T.sup.Vi.sub.,(3) (wherein M is R.sub.3SiO.sub.1/2, M.sup.Vi is R.sub.2PSiO.sub.1/2, D is R.sub.2SiO.sub.2/2, D.sup.Vi is RPSiO.sub.2/2, T is RSiO.sub.3/2 and T.sup.Vi is PSiO.sub.3/2, each R being independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms that has no aliphatic unsaturated bonds and P being an alkenyl group represented by (CH.sub.2).sub.aCHCH.sub.2 (where a is 0 or an integer from 1 to 6); and , , , , and are each independently 0 or a positive number, with the proviso that +++++200), wherein the content of the organopolysiloxane of formula (3) is from 0.1 to 40 times the weight of the crosslinked organopolysiloxane.

5. The siloxane composition of claim 1 which, when 30 wt% of the crosslinked organopolysiloxane is dissolved in a dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s (25 C.), has a viscosity at 25 C. of from 100 to 2,000,000 mPa.Math.s.

6. The siloxane composition of claim 1 which, when 30 wt% of the crosslinked organopolysiloxane is dissolved in toluene, has a viscosity at 25 C. of from 50 to 1,000,000 mPa.Math.s.

7. The siloxane composition of claim 1, wherein the organopolysiloxane of formula (1) has a weight-average molecular weight of 260 to 74,874 and the organohydrogenpolysiloxane of formula (2) has a weight-average molecular weight of 208 to 15,414.

8. The siloxane composition of claim 1, wherein the remaining amount of SiH groups, as calculated from the amount of hydrogen gas generated when alkali is added, is not more than 0.001 mol/100 g.

9. The siloxane composition of claim 1, wherein the crosslinked organopolysiloxane contains 10.8 to 50 moles of silalkylene linkages per 1,000 moles of siloxane units.

10. A siloxane composition comprising a crosslinked organopolysiloxane dissolved in a solvent, which crosslinked organopolysiloxane has a weight-average molecular weight of 5,000 to 300,000,000, contains 6.5 to 50 moles of silalkylene linkages per 1,000 moles of siloxane units, and is obtained by hydrosilylation of an organopolysiloxane having a structure of formula (1) below with an organohydrogenpolysiloxane having a structure of formula (2) below
M.sub.M.sup.Vi.sub.D.sub.D.sup.Vi.sub.T.sub.T.sup.Vi.sub.Q.sub.(1)
M.sub.M.sup.H.sub..Math.D.sub.D.sup.H.sub.T.sub.T.sup.H.sub.(2) (wherein M is R.sub.3SiO.sub.1/2, M.sup.Vi is R.sub.2PSiO.sub.1/2, D is R.sub.2SiO.sub.2/2, D.sup.Vi is RPSiO.sub.2/2, T is RSiO.sub.3/2, T.sup.Vi is PSiO.sub.3/2, M.sup.H is R.sub.2HSiO.sub.1/2, D.sup.H is RHSiO.sub.2/2, T.sup.H is HSiO.sub.3/2 and Q is SiO.sub.4/2, each R being independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms that has no aliphatic unsaturated bonds and P being an alkenyl group represented by (CH.sub.2).sub.aCHCH.sub.2 (where a is 0 or an integer from 1 to 6); and , , , , , , , , .Math., , , and are each independently 0 or a positive number, with the provisos that , and are not all 0, ++2, .Math., and are not all 0, and .Math.++2) in an amount of solvent that is at least 8 times the combined weight of the polysiloxanes of formulas (1) and (2) and using a platinum group metal compound, and when 30 wt% of the crosslinked organopolysiloxane is dissolved in toluene, has a viscosity at 25 C. of from 50 to 1,000,000 mPa.Math.s.

11. A siloxane composition comprising a crosslinked organopolysiloxane dissolved in a solvent, which crosslinked organopolysiloxane has a weight-average molecular weight of 5,000 to 300,000,000, contains 6.5 to 50 moles of silalkylene linkages per 1,000 moles of siloxane units, and is obtained by hydrosilylation of an organopolysiloxane having a structure of formula (1) below with an organohydrogenpolysiloxane having a structure of formula (2) below
M.sub.M.sup.Vi.sub.D.sub.D.sup.Vi.sub.T.sub.T.sup.Vi.sub.Q.sub.(1)
M.sub.M.sup.H.sub..Math.D.sub.D.sup.H.sub.T.sub.T.sup.H.sub.(2) (wherein M is R.sub.3SiO.sub.1/2, M.sup.Vi is R.sub.2PSiO.sub.1/2, D is R.sub.2SiO.sub.2/2, D.sup.Vi is RPSiO.sub.2/2, T is RSiO.sub.3/2, T.sup.Vi is PSiO.sub.3/2, M.sup.H is R.sub.2HSiO.sub.1/2, D.sup.H is RHSiO.sub.2/2, T.sup.H is HSiO.sub.3/2 and Q is SiO.sub.4/2, each R being independently an unsubstituted or substituted monovalent hydrocarbon group of 1 to 12 carbon atoms that has no aliphatic unsaturated bonds and P being an alkenyl group represented by (CH.sub.2).sub.aCHCH.sub.2 (where a is 0 or an integer from 1 to 6); and , , , , , , , , .Math., , , and are each independently 0 or a positive number, with the provisos that , and are not all 0, ++2, .Math., and are not all 0, and .Math.++2) in an amount of solvent that is at least 8 times the combined weight of the polysiloxanes of formulas (1) and (2) and using a platinum group metal compound, wherein the crosslinked organopolysiloxane contains 10.8 to 50 moles of silalkylene linkages per 1,000 moles of siloxane units.

Description

EXAMPLES

(1) Working Examples and Comparative Examples are given below to more concretely illustrate the invention, although the invention is not limited by these Examples. The viscosities mentioned below are all values measured at 25 C. using a Brookfield rotational viscometer.

(2) The symbols used in the following Examples to indicate siloxane compositions denote the following units.

(3) M: (CH.sub.3).sub.3SiO.sub.1/2

(4) M.sup.H: (CH.sub.3).sub.2HSiO.sub.1/2

(5) M.sup.Vi: (CH.sub.2CH)(CH.sub.3).sub.2SiO.sub.1/2

(6) D: (CH.sub.3).sub.2SiO.sub.2/2

(7) D.sup.H: (CH.sub.3)HSiO.sub.2/2

(8) D.sup.Vi: (CH.sub.2CH) (CH.sub.3) SiO.sub.2/2

(9) T: (CH.sub.3)SiO.sub.3/2

(10) T.sup.Vi: (CH.sub.2CH)SiO.sub.3/2

(11) Q: SiO.sub.4/2

Working Example 1

(12) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24.6D.sup.H.sub.2 (10 g) and 48 g of the branched vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2.4D.sub.147.7T.sub.0.4 (SiH groups: vinyl groups=1 mole: 1.083 moles) were mixed together in 696 g of toluene (corresponding to 12 times the total weight of the siloxanes), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. When the reaction had been carried out 5 hours at a temperature of 80 C., the amount of remaining SiH groups, based on the amount of generated hydrogen gas (the same applies below), was 0 mol/100 g.

(13) The resulting reaction product had a viscosity of 5.4 mPa.Math.s and a weight-average molecular weight of 52,000. The product obtained when toluene was removed by vacuum distillation had a viscosity of 8,000 mPa.Math.s. When 30 wt % of this crosslinked product was dissolved in toluene, the viscosity was 110 mPa.Math.s. When 30 wt % of the crosslinked product was dissolved in dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s, the viscosity was 290 mPa.Math.s. The amount of silethylene linkages per 1,000 moles of siloxane units, as determined by .sup.1H-NMR analysis, was 11.1 moles.

(14) Next, 696 g of the divinyl-terminated dimethylpolysiloxane denoted as M.sup.Vi.sub.2D.sub.66.8 was added to the reaction product and 3 hours of vacuum distillation at 150 C. and 10 mmHg under nitrogen bubbling was carried out, giving a composition that was 100% siloxane.

Working Example 2

(15) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24.6D.sup.H.sub.2, (10 g) and 48 g of the branched vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2.4D.sub.147.7T.sub.0.4 (SiH groups: vinyl groups=1 mole: 1.083 moles) were mixed together in 812 g of toluene (corresponding to 14 times the combined weight of the side chain-type methylhydrogenpolysiloxane and the branched vinylmethylpolysiloxane), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. When the reaction had been carried out 5 hours at a temperature of 80 C., the amount of remaining SiH groups was 0.00004 mol/100 g.

(16) The resulting reaction product was an oil having a viscosity of 4.0 mPa.Math.s, and had a weight-average molecular weight of 43,000. The product obtained when toluene was removed by vacuum distillation had a viscosity of 5,550 mPa.Math.s. When 30 wt % of this crosslinked product was dissolved in toluene, the viscosity was 80 mPa.Math.s. When 30 wt % of the crosslinked product was dissolved in dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s, the viscosity was 230 mPa.Math.s. The amount of silethylene linkages per 1,000 moles of siloxane units, as determined by .sup.1H-NMR analysis, was 11.1 moles.

(17) Next, 696 g of the dimethylpolysiloxane denoted as M.sub.2D.sub.27 was added to the reaction product and 3 hours of vacuum distillation at 150 C. and 10 mmHg under nitrogen bubbling was carried out, giving a composition that was 100% siloxane.

Working Example 3

(18) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24.6D.sup.H.sub.2, (10 g) and 48 g of the branched vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2.4D.sub.147.7T.sub.0.4 (SiH groups: vinyl groups=1 mole: 1.083 moles) were mixed together in 696 g of the dimethylpolysiloxane denoted as M.sub.2D.sub.27 (corresponding to 12 times the combined weight of the side chain-type methylhydrogenpolysiloxane and the branched vinylmethylpolysiloxane), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. When the reaction had been carried out 5 hours at a temperature of 80 C., the amount of remaining SiH groups was 0 mol/100 g.

(19) The resulting reaction product was an oil having a viscosity of 223 mPa.Math.s and a weight-average molecular weight of 150,000. The viscosity of the crosslinked product, as estimated by calculation from the foregoing product viscosity, was 983,000 mPa.Math.s. When 30 wt % of this crosslinked product was dissolved in toluene, the viscosity was 5,490 mPa.Math.s. When 30 wt % of the crosslinked product was dissolved in dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s, the viscosity was 8,700 mPa.Math.s. The amount of silethylene linkages per 1,000 moles of siloxane units in the crosslinked component (exclusive of M.sub.2D.sub.27), as determined by .sup.1H-NMR analysis, was 11.2 moles.

Working Example 4

(20) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24.6D.sup.H.sub.2 (10 g) and 58.9 g of the di-terminated vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2D.sub.150 (SiH groups: vinyl groups=1 mole: 1.097 moles) were mixed together in 696 g of the dimethylpolysiloxane denoted as M.sub.2D.sub.27 (corresponding to 12 times the combined weight of the side chain-type methylhydrogenpolysiloxane and the di-terminated vinylmethylpolysiloxane), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. When the reaction had been carried out 5 hours at a temperature of 80 C., the amount of remaining SiH groups was 0 mol/100 g.

(21) The resulting reaction product was an oil having a viscosity of 240 mPa.Math.s and a weight-average molecular weight of 130,000. The viscosity of the crosslinked product, as estimated by calculation from the foregoing product viscosity, was 590,000 mPa.Math.s. When 30 wt % of this crosslinked product was dissolved in toluene, the viscosity was 3,500 mPa.Math.s. When 30 wt % of the crosslinked product was dissolved in a dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s, the viscosity was 5,800 mPa.Math.s. The amount of silethylene linkages per 1,000 moles of siloxane units in the crosslinked component (exclusive of M.sub.2D.sub.27), as determined by .sup.1H-NMR analysis, was 10.8 moles.

Working Example 5

(22) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.27D.sup.H.sub.3 (10 g) and 76.2 g of the di-terminated vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2D.sub.144 (SiH groups: vinyl groups=1 mole: 1.069 moles) were mixed together in 1,034 g of the dimethylpolysiloxane denoted as M.sub.2D.sub.27 (corresponding to 12 times the combined weight of the side chain-type methylhydrogenpolysiloxane and the di-terminated vinylmethylpolysiloxane), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. When the reaction had been carried out 5 hours at a temperature of 80 C., the amount of remaining SiH groups was 0 mol/100 g.

(23) The resulting reaction product was an oil having a viscosity of 970 mPa.Math.s and a weight-average molecular weight of 300,000. The viscosity of the crosslinked product, as estimated by calculation from the foregoing product viscosity, was 17,000,000 mPa.Math.s. When 30 wt % of this crosslinked product was dissolved in toluene, the viscosity was 73,400 mPa.Math.s. When 30 wt% of the crosslinked product was dissolved in a dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s, the viscosity was 96,600 mPa.Math.s. The amount of silethylene linkages per 1,000 moles of siloxane units in the crosslinked component (exclusive of M.sub.2D.sub.27), as determined by .sup.1H-NMR analysis, was 6.3 moles.

Working Example 6

(24) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24D.sup.H.sub.4 (10 g) and 109.3 g of the di-terminated vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2D.sub.144 (SiH groups: vinyl groups=1 mole: 1.069 moles) were mixed together in 1,670 g of the dimethylpolysiloxane denoted as M.sub.2D.sub.27 (corresponding to 14 times the combined weight of the side chain-type methylhydrogenpolysiloxane and the di-terminated vinylmethylpolysiloxane), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. When the reaction had been carried out 5 hours at a temperature of 80 C., the amount of remaining SiH groups was 0.00005 mol/100 g.

(25) The resulting reaction product was an oil having a viscosity of 3,060 mPa.Math.s and a weight-average molecular weight of 400,000. The viscosity of the crosslinked product, as estimated by calculation from the foregoing product viscosity, was 202,400,000 mPa.Math.s. When 30 wt % of this crosslinked product was dissolved in toluene, the viscosity was 765,000 mPa.Math.s. When 30 wt % of the crosslinked product was dissolved in a dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s, the viscosity was 907,000 mPa.Math.s. The amount of silethylene linkages per 1,000 moles of siloxane units in the crosslinked component (exclusive of M.sub.2D.sub.27), as determined by .sup.1H-NMR analysis, was 6.5 moles.

Working Example 7

(26) The di-terminated methylhydrogenpolysiloxane denoted as M.sup.H.sub.2D.sub.40 (10 g) and 20 g of the side chain-type vinylmethylpolysiloxane denoted as M.sub.2D.sub.27D.sup.Vi.sub.3 (SiH groups: vinyl groups=1 mole: 1.083 moles) were mixed together in 480 g of the dimethylpolysiloxane denoted as M.sub.2D.sub.27 (corresponding to 16 times the combined weight of the side chain-type methylhydrogenpolysiloxane and the di-terminated vinylmethylpolysiloxane), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. When the reaction had been carried out 5 hours at a temperature of 80 C., the amount of remaining SiH groups was 0 mol/100 g.

(27) The resulting reaction product was an oil having a viscosity of 2,320 mPa.Math.s and a weight-average molecular weight of 440,000. The viscosity of the crosslinked product, as estimated by calculation from the foregoing product viscosity, was 238,000,000 mPa.Math.s. When 30 wt % of this crosslinked product was dissolved in toluene, the viscosity was 1,053,000 mPa.Math.s. When 30 wt % of the crosslinked product was dissolved in a dimethylpolysiloxane having a kinematic viscosity of 20 mm.sup.2/s, the viscosity was 893,600 mPa.Math.s. The amount of silethylene linkages per 1,000 moles of siloxane units in the crosslinked component (exclusive of M.sub.2D.sub.27), as determined by .sup.1H-NMR analysis, was 21 moles.

Comparative Example 1

(28) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24.6D.sup.H.sub.2 (10 g) and 58.9 g of the di-terminated vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2D.sub.150 (SiH groups: vinyl groups=1 mole: 1.097 moles) were mixed together without solvent dilution, following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. Gelling occurred at a temperature of about 60 C. The amount of remaining SiH groups was 0.005 mol/100 g.

Comparative Example 2

(29) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24.6D.sup.H.sub.2 (10 g) and 48 g of the branched vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2.4D.sub.147.7T.sub.0.4 (SiH groups: vinyl groups=1 mole: 1.083 moles) were mixed together in 232 g of toluene (equivalent to 4 times the total weight of the siloxanes), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. Gelling occurred at a temperature of about 70 C. The amount of remaining SiH groups was 0.007 mol/100 g.

Comparative Example 3

(30) The side chain-type methylhydrogenpolysiloxane denoted as M.sub.2D.sub.24.6D.sup.H.sub.2 (10 g) and 48 g of the branched vinylmethylpolysiloxane denoted as M.sup.Vi.sub.2.4D.sub.147.7T.sub.0.4 (SiH groups: vinyl groups=1 mole: 1.083 moles) were mixed together in 232 g of the dimethylpolysiloxane denoted by M.sub.2D.sub.27 (corresponding to 4 times the combined weight of the side chain-type methylhydrogenpolysiloxane and the branched vinylmethylpolysiloxane), following which a platinum catalyst having vinylmethylpolysiloxane coordinated thereto was added in an amount corresponding to a platinum weight of 2 ppm based on the total weight of the reaction system, and the temperature was raised. Gelling occurred at a temperature of about 70 C. The amount of remaining SiH groups was 0.003 mol/100 g.