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US 8,524,842 B2Granted
Silicone compositions crosslinkable into adhesive gels
AssigneeBluestar Silicones France SAS
InventorsBernd Jung, Joerg Dienemann, Catherine George
Life of this patent
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Abstract
Gels having viscoelastic qualities, physical stability and adhesive properties, well suited for a wide variety of end applications, are prepared by crosslinking, by hydrosilylation, silicone compositions which contain: a polyorganosiloxanes POS (I) of SiH type; a polyorganosiloxanes POS (II) of SiVi type (Vi=vinyl); a polyorganosiloxanes POS (III) of monofunctional SiVi type; a platinum-based catalyst (D); and optionally, a polyorganosiloxanes POS (IV) of polydimethylsiloxane type.
Claims17
A silicone composition comprising:
- (A) at least one polyorganosiloxane POS (I) having:
- a) endgroup siloxyl units of type M=(R)2(H)SiO1/2 in which the R radicals, which may be identical or different, are each an optionally substituted linear or branched C1-C6 alkyl radical and/or a substituted or unsubstituted aryl radical, and
- b) identical or different siloxyl units of type D=(R1)p(H)qSiO2/2 in which the R1 radicals have the same definition as R and p=1 or 2, g=0 or 1 and p+g=2;
- with the proviso that the polyorganosiloxane POS (I) comprises at least two SiH radicals per molecule;
- (B) at least one polyorganosiloxane POS (II) having:
- a) endgroup siloxyl units of type M=(X)s(R2)tSiO1/2 in which the R2 radicals have the same definition as R, the X radicals are alkenyl radicals having from 2 to 6 carbon atoms, s=0 or 1, 1=2 or 3 and s+t=3;
- and
- b) identical or different siloxyl units of type D=(X)u(R3)vSiO2/2 in which the R3 radicals have the same definition as R, the X radicals are alkenyl radicals having from 2 to 6 carbon atoms, u=0 or 1, v=1 or 2 and u+v=2,
- with the proviso that the polyorganosiloxane POS (II) comprises at least two X radicals per molecule;
- (C) at least one monofunctional polyorganosiloxane POS (III) which is essentially linear, having less than 2 mol % of siloxyl unit T=RSiO3/2, and which comprises, per molecule, one alkenyl radical (X) having from 2 to 6 carbon atoms directly bonded to a silicon atom, the said POS (III) having:
- a) identical or different endgroup siloxyl units of type M=(X)w(R4)xSiO1/2 in which the R4 radicals have the same definition as R, w=0, x=3;
- and
- b) at least one siloxyl unit D=(X)y(R5)zSiO2/2 in which the R5 radicals have the same definition as R, y=1, z=1,
- (D) an effective amount of at least one hydrosilylation reaction catalyst;
- and
- (E) at least one nonfunctionalized polyorganosiloxane POS (IV) having:
- a) endgroup siloxyl units of type M=(R6)3SiO1/2 in which the R6 radicals have the same definition as R, and
- b) identical or different siloxyl units of type D=(R7)2SiO2/2 in which the R7 radicals have the same definition as R;
- with the proviso that the amount of the constituents (A), (B), (C) and (E) is such that the molar ratio r of the hydrogen atoms bonded to silicon to the alkenyl radicals (X) bonded to silicon is 1:1;
- wherein the composition is crosslinkable into a gel by hydrosilylation and said composition, upon crosslinking, has a viscous modulus, (G″) and an elastic modulus (G′) greater than a comparable composition lacking component (C), POS (III).
17 more elements
A silicone composition consisting of:
- (A) at least one polyorganosiloxane POS (I) having:
- a) endgroup siloxyl units of type M=(R)2(H)SiO1/2 in which the R radicals, which may be identical or different, are each an optionally substituted linear or branched C1-C6 alkyl radical and/or a substituted or unsubstituted aryl radical, and
- b) identical or different siloxyl units of type D=(R1)p(H)gSiO2/2 in which the R1 radicals have the same definition as R and p=1 or 2, g=0 or 1 and g+g=2;
- with the proviso that the polyorganosiloxane POS (I) comprises at least two SiH radicals per molecule;
- (B) at least one polyorganosiloxane POS (II) having:
- a) endgroup siloxyl units of type M=(X)s(R2)tSiO1/2 in which the R2 radicals have the same definition as R, the X radicals are alkenyl radicals having from 2 to 6 carbon atoms, s=0 or 1, t=2 or 3 and s+t=3;
- and
- b) identical or different siloxyl units of type D=(X)u(R3)vSiO2/2 in which the R3 radicals have the same definition as R, the X radicals are alkenyl radicals having from 2 to 6 carbon atoms, u=0 or 1, v=1 or 2 and u+v=2,
- with the proviso that the polyorganosiloxane POS (II) comprises at least two X radicals per molecule;
- (C) at least one monofunctional polyorganosiloxane POS (III) which is essentially linear, having less than 2 mol % of siloxyl unit T=RSiO3/2, and which comprises, per molecule, one alkenyl radical (X) having from 2 to 6 carbon atoms directly bonded to a silicon atom, the said POS (III) having:
- a) identical or different endgroup siloxyl units of type M=(X)w(R4)xSiO1/2 in which the R4 radicals have the same definition as R, w=0, x=3;
- and
- b) at least one siloxyl unit D=(X)y(R5)zSiO2/2 in which the R5 radicals have the same definition as R, y=1, z=1,
- (D) an effective amount of at least one hydrosilylation reaction catalyst;
- and
- (E) at least one nonfunctionalized polyorganosiloxane POS (IV) having:
- a) endgroup siloxyl units of type M=(R6)3SiO1/2 in which the R6 radicals have the same definition as R, and
- b) identical or different siloxyl units of type D=(R7)2SiO2/2 in which the R7 radicals have the same definition as R;
- with the proviso that the amount of the constituents (A), (B), (C) and (E) is such that the molar ratio r of the hydrogen atoms bonded to silicon to the alkenyl radicals (X) bonded to silicon ranges is 1:1;
- wherein the composition is crosslinkable into a gel by hydrosilylation and said composition, upon crosslinking, has a viscous modulus, (G″) and an elastic modulus (G′) greater than a comparable composition lacking component (C), POS (III).
17 more elements
Dependencies are inferred from the claim text.