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US 6,387,487 B1Granted
Dual cure, low-solvent silicone pressure sensitive adhesives
AssigneeGeneral Electric Company
InventorsRonald A. Greenberg, Roy M. Griswold, Shaow B. Lin, David F. Townsend, Ference Horkay
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Abstract
A pressure sensitive adhesive composition includes an alkenyl-terminated polydiorganosiloxane, a silanol-terminated polydiorganosiloxane, a resinous copolymer, an organohydrogenpolysiloxane with terminal Si—H groups, a hydrosilation catalyst, and an organic cross-linking agent. The composition provides excellent high temperature adhesion properties and enables coatable formulations with low solvent content.
Claims35
A curable silicone coating composition, comprising:
- (A) about 20 to about 80 parts by weight of an alkenyl-terminated polydiorganosiloxane of formula (I)
- R2R12SiO(R12SiO)mSiR12R2 (I)
- wherein each R1 is independently an alkyl group having from 1 to about 10 carbon atoms or an aryl group, R2 is an alkenyl group having from 1 to about 10 carbon atoms, and m has an average value of about 20 to about 2000;
- (B) about 2 to about 80 parts by weight of a silanol-terminated polydiorganosiloxane of formula (II)
- R12Si(OH)O(R12SiO)pSiR12(OH) (II)
- wherein each R1 is independently an alkyl group as defined above, and the average value of p is chosen to provide a viscosity of about 100,000 centipoise to about 750,000 centipoise;
- (C) about 20 to about 80 parts by weight of a resinous copolymer containing R3SiO1/2 units and SiO4/2 units, where R is a hydrocarbon monovalent radical having from 1 to about 6 carbon atoms, said resinous copolymer having a molar ratio of R3SiO1/2 units to SiO4/2 units of about 0.6 to about 0.9;
- (D) an organohydrogenpolysiloxane of formula (III)
- R32HSiO(R32SiO)qSiHR32 (III)
- wherein each R3 is independently an alkyl group having 1 to about 10 carbon atoms or an aryl group;
- q has an average value of 1 to about 300;
- the molar ratio of silicon-bonded hydrogen groups in (D) to silicon-bonded alkenyl groups in (A) being about 0.8:1 to about 1.5:1;
- (E) a catalytic amount of a hydrosilation catalyst;
- and
- (F) about 0.2 to about 6 parts by weight of a cross-linking agent comprising an organic peroxide or an organic azo compound;
- wherein all parts by weight are based on the weight of the entire composition.
13 more elements
A curable silicone coating composition, comprising:
- (A) about 20 to about 40 parts by weight of an alkenyl-terminated polydiorganosiloxane of formula (I)
- R2R12SiO(R12SiO)mSiR12R2 (I)
- wherein R1 is methyl, R2 is vinyl, and m has an average value of about 120 to about 1000;
- (B) about 5 to about 15 parts by weight of a silanol-terminated polydiorganosiloxane of formula (II)
- R12Si(OH)O(R12SiO)pSiR12(OH) (II)
- wherein R1 is methyl, and the average value of p is chosen to provide a viscosity of about 250,000 centipoise to about 450,000 centipoise;
- (C) about 35 to about 45 parts by weight of a resinous copolymer containing R3SiO1/2 units and SiO4/2 units, where R is methyl, said resinous copolymer having a molar ratio of R3SiO1/2 units to SiO4/2 units from about 0.6 to about 0.9;
- (D) an organohydrogenpolysiloxane of formula (III)
- R32HSiO(R32SiO)qSiHR32 (III)
- wherein R3 is methyl;
- q has an average value of 1 to about 300;
- the molar ratio of silicon-bonded hydrogen groups in (D) to silicon-bonded alkenyl groups in (A) being about 1:1;
- (E) a catalytic amount of a hydrosilation catalyst comprising platinum;
- (F) about 0.2 to about 6 parts by weight of a cross-linking agent comprising an benzoyl peroxide;
- (G) optionally, not greater than about 10 percent by weight of an organic solvent having a boiling point not greater than about 250° C.;
- and
- (H) about 0.01 to about 0.2 parts by weight of a platinum catalyst inhibitor selected from the group consisting of 3-methyl-1-butyne-3-ol, methyl maleate, butyl maleate, and mixtures comprising at least one of the foregoing inhibitors;
- wherein all parts by weight are based on the weight of the entire composition.
15 more elements
Dependencies are inferred from the claim text.