One-part structural epoxy resin adhesives containing elastomeric tougheners capped with phenols and hydroxy-terminated acrylates or hydroxy-terminated methacrylates

Patent metadata

Field	Value
Publication number	US-9676887-B2
Application number	US-201414263134-A
Country	US
Kind code	B2
Filing date	Apr 28, 2014
Priority date	Aug 11, 2008
Publication date	Jun 13, 2017
Grant date	Jun 13, 2017

Abstract

Structural adhesives are prepared from an elastomeric toughener that contains urethane and/or urea groups, and have some terminal isocyanate groups that are capped with a phenol and other terminal isocyanate groups that are capped with a hydroxy-functional acrylate or a hydroxy-functional methacrylate. In certain embodiments, the presence of both types of capping on the toughener leads to higher impact peel strengths and a greater level of cohesive failure, than when the toughener is capped with a phenol an hydroxy-functional acrylate or hydroxy-functional methacrylate alone.

First claim

What is claimed is:

1. A structural adhesive comprising:
A) at least one epoxy resin;
B) an elastomeric toughener represented by structure (I)

wherein p is from 1.5 to 8; wherein a portion of the A groups comprises a residue after removal from a hydrogen from a hydroxyl group of a hydroxy-functional acrylate or methacrylate; another portion of the A groups comprises a residue of a phenol; Y is a residue of an isocyanate-terminated prepolymer after removal of the terminal isocyanate groups; and Y comprises at least one elastomeric segment;
C) one or more epoxy curing agents;
D) a liquid rubber-modified epoxy resin, a core-shell rubber, or both a liquid rubber modified epoxy resin and a core-shell rubber;
E) a catalyst; and
F) a latent free radical initiator that can be activated by radiation or by heating to a temperature of from 80 to 130° C.

2. A cured composition obtained by curing the structural adhesive of claim 1 .

3. The cured composition of claim 2 , having a Young's modulus of about 1000 MPa or greater.

4. The cured composition of claim 2 , having a tensile strength of about 20 MPa or greater.

5. The structural adhesive of claim 1 , which when cured has a Young's modulus of about 1000 MPa or greater.

6. The structural adhesive of claim 1 , which when cured has a tensile strength of about 20 MPa or greater.

7. The structural adhesive of claim 1 which, when applied to cold rolled steel or galvaneal and cured to obtain a cured layer 1.5 mm thick, has a lap shear strength of about 15 MPa or greater.

Assignees

• Dow Global Technologies Llc

Inventors

• Lutz Andreas
• Schneider Daniel

Classifications

• C08G18/672

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

• C08L2666/20

  Macromolecular compounds having nitrogen in the main chain according to C08L75/00 - C08L79/00; Derivatives thereof · CPC title

• C08L63/00

  Compositions of epoxy resins; Compositions of derivatives of epoxy resins · CPC title

• C08L75/16

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

• C09J175/16

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