Polyurethane-acrylate epoxy adhesive

Patent metadata

Field	Value
Publication number	US-10066136-B2
Application number	US-201515121663-A
Country	US
Kind code	B2
Filing date	Mar 31, 2015
Priority date	Apr 22, 2014
Publication date	Sep 4, 2018
Grant date	Sep 4, 2018

Abstract

The invention relates to isocyanate-free elastomer adhesives based on hybrid urethane-acrylate epoxies. The hybrid shows properties consistent for structural adhesives with excellent mechanical and thermal stability, and low read-through. The adhesives are suitable for use in industry, e.g., as adhesives for automotive applications.

First claim

The invention claimed is:

1. An adhesive composition comprising resin portion A and crosslinker portion B:
the resin portion A having a viscosity of 30 Pa·sec or less at 25° C., the resin portion A comprising a mixture of
A1) an acrylate-tipped polyurethane wherein the acrylate-tipped polyurethane contains a polyether chain having a mass of at least 3000 atomic mass units, and
A2) an epoxy resin wherein the epoxy resin is a polyglycidyl ether of a polyphenol, has an epoxy equivalent weight of up to 225 and is a liquid at 25° C.;

wherein the weight ratio of A1) to A2) is greater than or about 30:70 and less than or about 60:40;
the crosslinker portion B comprising a mixture of
B1) a polythiol,
B2) a polyamine, and
B3) a catalyst,

wherein the weight ratio of B1) to B2 is 25:75 to 99:1.

2. The adhesive composition of claim 1 , wherein the acrylate-tipped polyurethane can be obtained by reacting a polyol with a multifunctional isocyanate to complete reaction of the isocyanate to obtain a pre-polymer, and capping the pre-polymer with acrylate groups.

3. The adhesive composition of claim 1 wherein the polythiol comprises 2,3-di((2-mercaptoethyl)thio)-1-propanethiol.

4. The adhesive composition of claim 1 wherein the polyamine comprises 2,4,6-tri(dimethylaminomethyl)phenol.

5. The adhesive composition of claim 1 wherein the catalyst comprises 1,8-diazobicyclo[5.4.0]undec-7-ene.

6. The adhesive composition of claim 1 wherein the crosslinker portion B a highly polar filler.

7. The adhesive composition of claim 6 , wherein the highly polar filler comprises a metal oxide or hydroxide.

8. A method of bonding two surfaces comprising:
a) providing a resin portion A having a viscosity of 30 Pa·sec or less at 25° C., the resin portion A comprising a mixture of A1) an acrylate-tipped polyurethane and A2) an epoxy resin, wherein the acrylate-tipped polyurethane contains a polyether chain having a mass of at least 3000 atomic mass units, the epoxy resin is a polyglycidyl ether of a polyphenol, has an epoxy equivalent weight of up to 225 and is a liquid at 25° C., and the weight ratio of A1) to A2) is greater than or about 30:70 and less than or about 60:40; and
b) providing a crosslinker portion B comprising a mixture of B1) a polythiol, B2) a polyamine and B3) a catalyst, wherein the weight ratio of B1) to B2 is 25:75 to 99:1;
c) combining the resin portion A and the crosslinker portion B to form an uncured adhesive;
d) applying the uncured adhesive such that it is in contact with a first surface and a second surface; and then
e) curing the uncured adhesive in contact with the first surface and the second surface.

9. The method of claim 8 wherein the polythiol comprises 2,3-di((2-mercaptoethyl)thio)-1-propanethiol and the polyamine comprises isophorone diamine.

10. The method of claim 9 wherein the catalyst comprises 1,8-diazobicyclo[5.4.0]undec-7-ene.

11. The method of claim 10 wherein the crosslinker portion B comprises a metal oxide or hydroxide.

Assignees

• Dow Global Technologies Llc

Inventors

• Krishnan Bindu
• Grier Laura A
• Heath William H
• Colson Adam C
• Gelfer Mikhail Y
• Jialanella Gary L

Classifications

• C08G18/4841 Primary

  containing oxyethylene end groups · CPC title

• C08G18/672

  Esters of acrylic or alkyl acrylic acid having only one group containing active hydrogen · CPC title

• C08G18/242

  organometallic compounds containing tin-carbon bonds · CPC title

• C09J175/16

  having terminal carbon-to-carbon unsaturated bonds · CPC title

• C08K3/20

  Oxides; Hydroxides {(graphene oxides C08K3/042)} · CPC title