Claims
- 1. A liquid composition which on exposure to actinic radiation polymerizes to form a heat-curable solid film adhesive, said composition comprising (A) a heat-curable phenol-aldehyde resol resin, (B) a photopolymerizable polyurethane or polyester having, on average, more than one polymerizable acrylic group per molecule, or a mixture of said polyurethane and said polyester, (C) a photopolymerization initiator for (B) and (D) a polyvinylacetal.
- 2. A composition according to claim 1, in which (A) is a phenol-formaldehyde resol.
- 3. A composition according to claim 1, in which component (B) is a photopolymerizable polyurethane which is a reaction product of (I) an isocyanate-terminated polyurethane prepolymer with (II) a hydroxyl group-containing acrylic compound.
- 4. A composition according to claim 3, in which the prepolymer (I) is a reaction product of a polyoxyalkylene glycol with a cycloaliphatic diisocyanate.
- 5. A composition according to claim 3, in which the acrylic compound (II) is a hydroxyalkyl acrylate or hydroxyalkyl methacrylate.
- 6. A composition according to claim 1, in which the photopolymerizable polyester is a reaction product of a hydroxyl-terminated polyester with an acrylic compound having a hydroxyl-reactive group which is a carboxyl group, a carboxylic acid halide group or an epoxide group.
- 7. A composition according to claim 1, in which the photopolymerizable polyester is a reaction product of a carboxyl-terminated polyester with an acrylic compound having a hydroxyl group or an epoxide group.
- 8. A composition according to claim 1, in which the initiator (C) is an alpha-substituted acetophenone or a mixture thereof with a thioxanthone or a benzophenone.
- 9. A composition according to claim 1, in which the polyvinylacetal (D) is a polyvinylbutyral.
- 10. A composition according to claim 9, in which the polyvinylbutyral has a softening point of at least 150.degree. C.
- 11. A composition according to claim 9, in which the polyvinylbutyral has a softening point of at least 200.degree. C.
- 12. A composition according to claim 1, which also contains at least one liquid acrylic monomer as reactive diluent.
- 13. A composition according to claim 1 which also contains, as toughening agent, a polymer having repeating aromatic ether groups in the backbone thereof.
- 14. A composition according to claim 1 in which the weight ratio of resol (A) to total photopolymerizable acrylate is from 1:1 to 10:1.
- 15. A composition according to claim 1, in which the resol (A) comprises 60 to 90% by weight of the liquid composition, and the photopolymerizable polyurethane and/or polyester (B) comprises 5 to 30% by weight of the composition.
- 16. A composition according to claim 1, which contains an acrylic monomer reactive diluent in an amount up to 30% by weight of the resol (A).
- 17. A composition according to claim 1, in which the amount of polyvinylacetal (D) in the liquid composition is from 0.2 to 20% by weight of the composition.
- 18. A solid film adhesive obtained by exposing to actinic radiation a layer of a liquid composition according to claim 1.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9114099 |
Jun 1991 |
GBX |
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Parent Case Info
This application is a continuation of application Ser. No. 07/903,836, filed Jun. 24, 1992, now abandoned.
US Referenced Citations (9)
Foreign Referenced Citations (4)
Number |
Date |
Country |
1267473 |
Apr 1990 |
CAX |
4057879 |
Feb 1992 |
JPX |
4163040 |
Jun 1992 |
JPX |
1575361 |
Sep 1980 |
GBX |
Continuations (1)
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Number |
Date |
Country |
Parent |
903836 |
Jun 1992 |
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