1K UV and thermal cure high temperature debondable adhesive
View Patent ↗The present invention relates to one-component UV and thermal curable temporary adhesives for use in high temperature applications, and particularly to adhesives for the temporary attachment of one substrate to another substrate, the adhesives comprising (i) the partial hydrosilylation reaction product of the reaction between the vinyl groups on 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane and the terminal Si—H hydrogens on a silane or siloxane having terminal Si—H hydrogens, and (ii) a photo and/or thermal radical cure initiator. Also encompassed are assemblies including such an adhesive and methods of using the adhesives.
1. A one-component debondable, high temperature stable adhesive composition comprising
(i) a partial hydrosilylation reaction product of a reaction between vinyl groups on 1,3,5,7-tetravinyl-1,3,5,7-tetramethylcyclotetrasiloxane and terminal Si—H hydrogens on a silane or siloxane having terminal Si—H hydrogens; and
(ii) a photo and/or thermal radical cure initiator.
2. The debondable adhesive composition according to claim 1 in which the silane or siloxane having terminal Si—H hydrogens has a structure
wherein R is selected from the group consisting of a C 1 to C 10 alkyl group, an aryl group, an oxygen, —(O—SiMe 2 ) n -O—, —(O—SiAr 2 ) n —O—, —(O—SiMeAr) n —O—, and a combination of any of these groups, in which n is an integer of at least 1, Me is a methyl group, and Ar is an aryl group; and in which each of R 1 , R 2 , R 3 , R 4 , R 5 , and R 6 , independently is a C 1 to C 10 alkyl group or an aryl group.
3. The debondable adhesive composition according to claim 2 in which the silane or siloxane having terminal Si—H hydrogens is selected from the group consisting of polydialkylsiloxane, polyalkylaryl siloxane, tetraalkyldisiloxane, and polydiaryl siloxane.
4. The debondable adhesive composition according to claim 1 , wherein the radical cure initiator is selected from the group consisting of α-hydroxy ketones, benzophenones, phenyl glyoxylic acids, acyl-phosphine oxides, bis-acyl-phosphine oxides, dicumene peroxide, cumene hydroperoxide, and 2-hydroxy-2-methyl-1-phenyl propan-1-one.
5. The debondable adhesive composition according to claim 1 , further comprising a cure speed aid selected from acrylated and/or methacrylated siloxanes.
6. The debondable adhesive composition according to claim 1 , further comprising a filler material.
7. The debondable adhesive composition according to claim 1 , wherein the composition is free of additional crosslinkers, preferably free of hydrosilane and hydrosiloxane crosslinkers.
8. An assembly of a substrate and a carrier, comprising a one-component debondable, high temperature stable adhesive composition according to claim 1 disposed between the carrier and the substrate.
9. A method for bonding a substrate to a carrier comprising:
(a) providing a substrate and a carrier,
(b) disposing a one-component debondable adhesive composition according to claim 1 on the substrate and/or the carrier,
(c) contacting the substrate and carrier so that the debondable adhesive composition is disposed between the carrier and the substrate, forming an assembly,
(d) radically curing the debondable adhesive by
(i) heating the assembly, or
(ii) exposing the assembly to radiation, or
(iii) exposing the assembly to radiation followed by heating.
10. A method for debonding a substrate from a carrier comprising:
(a) providing a substrate and a carrier;
(b) disposing a one-component debondable adhesive composition according to claim 1 on the substrate and/or the carrier;
(c) contacting the substrate and carrier so that the debondable adhesive composition is disposed between the carrier and the substrate, forming an assembly;
(d) radically curing the debondable adhesive by
(i) heating the assembly, or
(ii) exposing the assembly to radiation, or
(iii) exposing the assembly to radiation followed by heating; and
(e) mechanically separating the substrate and the carrier, optionally after allowing the assembly to come to ambient temperature and/or one or more steps of processing the substrate.