Organopolysiloxane composition and method for producing same, and silicone composition for mist suppressor as well as solvent-free release paper or release film

Abstract

An organopolysiloxane composition obtained by dissolving in a solvent an organopolysiloxane crosslinked product obtained by repeating one or more times a process of again introducing an organopolysiloxane and an organohydrogenpolysiloxane to a product, obtained by conducting an addition reaction of an organopolysiloxane of a specific structure and an organohydrogenpolysiloxane of a specific structure using a platinum group metal-based compound in 10-50 times the total mass of these polysiloxanes, and conducting an addition reaction using a platinum group metal-based compound.

1 . An organopolysiloxane composition obtained by the steps of:
 effecting addition reaction of an organopolysiloxane of structure having the formula (1) and an organohydrogenpolysiloxane of structure having the formula (2) in a solvent in the presence of a platinum group metal base compound, the amount of the solvent being 10 to 50 times the total weight of the polysiloxanes of formulae (1) and (2), to form a product,   adding the organopolysiloxane of structure having the formula (1) and the organohydrogenpolysiloxane of structure having the formula (2) again to the product,   effecting addition reaction in the presence of the platinum group metal base compound, and   repeating at least one time the addition and reaction steps, thereby yielding an organopolysiloxane crosslinked product, the organopolysiloxane composition having the organopolysiloxane crosslinked product dissolved in the solvent,
     M   α   M   Vi   β   D   γ   D   Vi   δ   T   ε   T   Vi   ζ   Q   η   (1)
 
     M   θ   M   H   ι   D   κ   D   H   λ   T   μ   T   H   ν   Q   η   (2)
 
   
       wherein M is R 3 SiO 1/2 , M Vi  is R 2 PSiO 1/2 , D is R 2 SiO 2/2 , D Vi  is RPSiO 2/2 , T is RSiO 3/2 , T Vi  is PSiO 3/2 , M H  is R 2 HSiO 1/2 , D H  is RHSiO 2/2 , T H  is HSiO 3/2 , Q is SiO 4/2 , R is each independently a substituted or unsubstituted C 1 -C 12  monovalent hydrocarbon group free of aliphatic unsaturation, P is an alkenyl group: —(CH 2 ) a —CH═CH 2  wherein a is 0 or an integer of 1 to 6, α, β, γ, δ, ε, ζ, η, θ, ι, κ, λ, μ, and ν are each independently 0 or a positive number, 3, 6 and are not equal to 0 at the same time, β+δ+ζ≥2, ι, λ, and ν are not equal to 0 at the same time, ι+λ+ν≥2, β+δ+ζ and ι+λ+ν are not equal to 2 at the same time. 
     
     
         2 . The organopolysiloxane composition of  claim 1  wherein the solvent is a linear dimethylpolysiloxane having a viscosity of 1 to 500 mm 2 /s (25° C.). 
     
     
         3 . The organopolysiloxane composition of  claim 1  or  2  wherein the organohydrogenpolysiloxane of structure having the formula (1) has a weight average molecular weight of 186 to 40,000, and the organopolysiloxane of structure having the formula (2) has a weight average molecular weight of 134 to 10,000. 
     
     
         4 . The organopolysiloxane composition of  claim 1  wherein the organopolysiloxane of structure having the formula (1) has a structure represented by M Vi   2 D γ , M 2 D γ D Vi   δ , M Vi   3 D γ T 1 , M Vi   4 D γ T 2 , M Vi   2 D γ D Vi   δ , M Vi   2 D γ Q 1 , or M α D γ D Vi   δ T Vi   ζ  wherein M, M Vi , D, D Vi , T, T Vi , α, γ, δ, and ζ are as defined above. 
     
     
         5 . The organopolysiloxane composition of  claim 1  wherein the organohydrogenpolysiloxane of structure having the formula (2) has a structure represented by M H   2 D κ , M 2 D H   λ , M 2 D κ D H   λ , M H   2 D κ D H   λ , M H   3 D κ T 1 , M H   4 D κ T 2 , or M θ D κ D H   λ T H   ν  wherein M, D, T, M H , D H , T E , Q, θ, κ, λ, and ν are as defined above. 
     
     
         6 . The organopolysiloxane composition of  claim 1  wherein the organopolysiloxane crosslinked product contains 5 to 100 mol of silethylene bonds per 1,000 mol of siloxane units. 
     
     
         7 . The organopolysiloxane composition of  claim 1  wherein when the organopolysiloxane crosslinked product is dissolved in a linear dimethylpolysiloxane having a viscosity at 25° C. of 20 mm 2 /s in a concentration of 9 to 12% by weight, the solution has a viscosity at 25° C. of 20 mm 2 /s to 2,000 mm 2 /s. 
     
     
         8 . The organopolysiloxane composition of  claim 1  wherein when the organopolysiloxane crosslinked product is dissolved in a linear dimethylpolysiloxane having a viscosity at 25° C. of 20 mm 2 /s and/or toluene in a concentration of 0.9 to 1.2% by weight, at least 95% by weight of the organopolysiloxane crosslinked product passes through a cellulose acetate cartridge filter. 
     
     
         9 . A method for preparing an organopolysiloxane composition comprising the steps of:
 effecting addition reaction of an organopolysiloxane of structure having the formula (1) and an organohydrogenpolysiloxane of structure having the formula (2) in a solvent in the presence of a platinum group metal base compound, the amount of the solvent being 10 to 50 times the total weight of the polysiloxanes of formulae (1) and (2), to form a product,   adding the organopolysiloxane of structure having the formula (1) and the organohydrogenpolysiloxane of structure having the formula (2) again to the product,   effecting addition reaction in the presence of the platinum group metal base compound,   repeating at least one time the addition and reaction steps, thereby yielding an organopolysiloxane crosslinked product,
     M   α   M   Vi   β   D   γ   D   Vi   δ   T   ε   T   Vi   ζ   Q   η   (1)
 
     M   θ   M   H   ι   D   κ   D   H   λ   T   μ   T   H   ν   Q   η   (2)
 
   
       wherein M is R 3 SiO 1/2 , M Vi  is R 2 PSiO 1/2 , D is R 2 SiO 2/2 , D Vi  is RPSiO 2/2 , T is RSiO 3/2 , T Vi  is PSiO 3/2 , M H  is R 2 HSiO 1/2 , D H  is RHSiO 2/2 , T H  is HSiO 3/2 , Q is SiO 4/2 , R is each independently a substituted or unsubstituted C 1 -C 12  monovalent hydrocarbon group free of aliphatic unsaturation, P is an alkenyl group: —(CH 2 ) a —CH═CH 2  wherein a is 0 or an integer of 1 to 6, α, β, γ, δ, ε, ζ, η, θ, ι, κ, λ, μ, and ν are each independently 0 or a positive number, 3, 6 and are not equal to 0 at the same time, β+δ+ζ≥2, ι, λ, and ν are not equal to 0 at the same time, ι+λ+ν≥2, β+δ+ζ and ι+λ+ν are not equal to 2 at the same time. 
     
     
         10 . The method of  claim 9  wherein the addition reaction of first stage has a conversion rate of at least 90%. 
     
     
         11 . The method of  claim 9  or  10  wherein a solvent having a boiling point of 50° C. to 200° C. is used as the solvent in the amount of 10 to 50 times the total weight of the polysiloxanes of formulae (1) and (2), addition reaction is effected plural divided times, and after the organopolysiloxane crosslinked product is obtained, vinylmethylpolysiloxane is added thereto and the solvent is then removed. 
     
     
         12 . A mist suppressant comprising the organopolysiloxane composition of  claim 1 . 
     
     
         13 . The mist suppressant of  claim 12  for use in a solventless release paper or film-forming silicone composition. 
     
     
         14 . A solventless release paper or film-forming silicone composition comprising
 (A) 100 parts by weight of an organopolysiloxane containing at least two silicon-bonded alkenyl groups per molecule,   (B) 0.1 to 30 parts by weight of an organohydrogenpolysiloxane containing on average at least three silicon-bonded hydrogen atoms per molecule,   (C) a catalytic amount of a platinum group metal base catalyst, and   (D) 0.01 to 20 parts by weight of the mist suppressant of  claim 12  or  13 .