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US 6,486,237 B1Granted
Silicone composition cross-linkable into adhesive gel and absorber with microspheres
AssigneeRhodia Chimie
InventorsFabienne Howe, Christian Pusineri
Life of this patent
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Abstract
The invention concerns a silicone composition cross-linkable by hydrosilylation into adhesive gel and absorber, characterized in that it comprises:(I) at least a polyorganosiloxane POS (I); (II) at least a polyorganosiloxane POS (II); (III) at least an adhesive promoter (III); (IV) hollow organic microspheres ; (V) optionally at least a polyorganosiloxane POS (V) particularly useful as diluent of POS (I); (VI) an effective amount of hydrosilylation catalyst, preferably of the platinous type.
Claims11
A silicone composition crosslinkable by hydrosilylation into an adhesive and cushioning gel, comprising:
- (I)—at least one polyorganosiloxane POS (I) comprising:
- end siloxyl units of formula M=(R)2(Hrf)SiO1/2, at a level of 0.1 to 1 molar %,
- wherein:
- R=CH3 and Hrf=vinyl, and
- identical or different siloxyl units of formula D=(R1)p(Hrf)qSiO2/2, at a level of 99 to 99.9 molar %, wherein R1=CH3, p=2 and q=0,
- (II)—at least one polyorganosiloxane POS (II) comprising:
- identical or different siloxyl units of formula R2SiO2/2, wherein R is a linear C1-C6 alkyl group, or an aryl group, optionally substituted,
- end siloxyl units M=(Hrf)s(R2)tSiO1/2, at a level of 1 to 6 molar %, wherein units Hrf=H, R2=CH3, s=1 and t=2
- identical or different siloxyl units D=(Hrf)u(R3)vSiO2/2, at a level of 10 to 50 molar %, wherein units R3=CH3, Hrf=H, u=1 and v=1
- with the further proviso that at least one of the D units of the POS (II) carries an Hrf (u=1, v=1),
- (III)—at least one adhesion promoter (III), selected from the group consisting of:
- extending polyorganosiloxanes POS (III) exhibiting:
- end siloxyl units M=(Hrf)w(R4)xSiO1/2, at a level of 8 to 20 molar %, wherein units Hrf=H, R4=CH3, w=1 and x=2, with the further proviso
- that the Hrfs of the POS (III) react at least with the Hrfs of the end M units of the POS (I),
- that the ratio:
- r 1 = number of Hrf groups in the POS ( III ) number of Hrf groups in the POS ( II ) and in the POS ( III ) × 100
- is less than or equal to 95%, and
- that the ratio:
- r 2 = number of Hrf groups in the POS ( II ) and in the POS ( III ) number of Hrf groups in the POS ( I )
- is less than or equal to 0.9;
- and
- siloxyl units D=(R5)2SiO2/2, at a level of 80 to 92 molar %, wherein units R5=CH3,
- organosilanes comprising, per molecule, at least one C2-C6 alkenyl group, of the following formula (III-2-1)
- wherein
- R1, R2 and R3 are hydrogen or hydrocarbonaceous radicals which are identical to or different from one another,
- U is a linear or branched C1-C4 alkylene or a divalent group of formula —CO—O-alkylene- wherein the alkylene group has the definition given above and is connected to the Si atom,
- R4 and R5, which are identical or different, are a linear or branched C1-C4 alkyl group,
- x′=0 or 1,
- x=0 to 2, preferably 0 or 1 and more preferably still 0 and
- organosilicon compounds comprising at least one epoxy group.
- (IV)—organic hollow microspheres,
- (V)—at least one linear polyorganosiloxane POS (V) comprising end siloxyl units M=(R6)3SiO1/2 and siloxyl units D=(R7)2SiO2/2 wherein R6 and R7 identical different from one another have the same definition as R, and having a lower dynamic viscosity than that of the POS (I), and
- (VI)—an effective amount of hydrosilylation catalyst.
30 more elements
Dependencies are inferred from the claim text.