Adhesive film or adhesive tape based on epoxides
A thermally curable adhesive in strip or film form, having a thickness in the range of 0.1 to 5 mm, containing: a) at least one reactive epoxy prepolymer, b) at least one latent hardener for epoxies, and c) one or more elastomers that are selected from: c1) thermoplastic polyurethanes, c2) thermoplastic isocyanates, and c3) block copolymers having thermoplastic polymer blocks. Further components can additionally be contained, for example a blowing agent for foaming. The adhesive in the uncured state at 22° C. is bendable or wrappable and can be extended at least 100% before tearing. It can be laid onto a foil. It can be used, for example, for adhesive bonding of planar, tubular, or cylindrical components, preferably components made of metal, wood, ceramic, or ferrites.
1. An adhesive material for the joining of pipes comprising a thermally curable adhesive agent in strip or film form having a thickness of 0.1 to 5 mm, said thermally curable adhesive agent in strip or film form comprising:
a) at least one reactive epoxy prepolymer comprising an epoxy resin that is solid at 22° C.,
b) at least one latent hardener for epoxies, and
c) one or more block copolymers selected from the group consisting of:
styrene-butadiene-(meth)acrylate,
styrene-butadiene-(meth)acrylic acid ester,
ethylene-(meth)acrylic acid ester-glycidyl(meth)acrylic acid ester,
ethylene-(meth)acrylic acid ester-maleic acid anhydride, and
methyl methacrylate-butyl acrylate-methyl methacrylate;
when said adhesive material comprises the thermally curable adhesive agent in strip form, the adhesive material comprises a free-standing extruded strip of the thermally curable adhesive agent or an extruded strip of the thermally curable adhesive agent covered on one side with a carrier foil or a release paper and optionally covered on its other side with a release paper;
when said adhesive material comprises the thermally curable adhesive agent in film form, the adhesive material comprises a film of the thermally curable adhesive agent on a carrier foil or a release paper and optionally covered with a release paper;
wherein curing of the thermally curable adhesive agent is initiated when heated to temperatures in a range from about 60° C. to about 200° C.; and
wherein the thermally curable adhesive agent in strip or film form at 22° C. is bendable or wrappable and can be elongated at least 100% before it tears.
2. The adhesive material according to claim 1 , wherein the one or more block copolymers contain blocks having a glass transition temperature below 15° C. and blocks having a glass transition temperature above 25° C.
3. The adhesive material according to claim 1 , wherein the thermally curable adhesive agent in strip or film form further comprises d) rubber particles.
4. The adhesive material according to claim 1 , wherein the thermally curable adhesive agent in strip or film form further comprises e) inorganic particles having a shell constructed of organic polymers.
5. The adhesive material according to claim 1 , wherein the thermally curable adhesive agent in strip or film form further comprises f) at least one blowing agent.
6. The adhesive material according to claim 1 , wherein the thermally curable adhesive agent in strip or film form further comprises g) metal powder.
7. The adhesive material according to claim 1 comprising: an extruded strip of the thermally curable adhesive agent covered on one side with a carrier foil or a release paper and optionally covered on its other side with a release paper; or a film of the thermally curable adhesive agent on a carrier foil or a release paper and optionally covered with a release paper.
8. A method for connecting pipes, comprising the steps of:
providing a first pipe and a second pipe, wherein the first pipe comprises an end portion dimensioned and disposed to receive an end portion of the second pipe;
providing the adhesive material according to claim 1 ;
removing a first release paper, as necessary, to expose one side of the thermally curable adhesive agent in strip or film form;
applying the adhesive material onto the end portion of the second pipe such that the thermally curable adhesive agent is in contact with the end portion of the second pipe;
removing a second release paper, as necessary, to expose another side of the thermally curable adhesive agent;
joining the end portion of the first pipe with the end portion of the second pipe such that the thermally curable adhesive agent is disposed between the end portions of the first and second pipes; and
exposing the joined ends of the first pipe and the second pipe to temperatures in a range of about 60° C. to about 200° C. to cure the thermally curable adhesive agent.
9. A connected pair of pipes produced by the method according to claim 8 .