Photocurable epoxy resin systems

Patent metadata

Field	Value
Publication number	US-10508199-B2
Application number	US-201615258547-A
Country	US
Kind code	B2
Filing date	Sep 7, 2016
Priority date	Mar 7, 2014
Publication date	Dec 17, 2019
Grant date	Dec 17, 2019

Abstract

The invention is directed to a photocurable epoxy resin composition that is tougher and more flexible and contains 30 to 90 wt % of at least one aromatic epoxy resin; 2 to 30 wt % of at least one core-shell rubber (CSR); up to 20 wt % of at least one flexibilizer comprising reactive functional groups selected from among epoxy groups, carboxylate groups, amino groups and/or hydroxyl groups; and 1 to 4 wt % of at least one cationic photoinitiator. Also disclosed are the use of said composition for sealing and/or coating materials as well as corresponding coating/sealing processes.

First claim

What is claimed is:

1. A photocurable epoxy resin composition comprising:
(a) 30 to 90 wt % of at least one aromatic epoxy resin;
(b) 2 to 30 wt % of at least one core-shell rubber as toughener;
(c) 1 to 20 wt % of at least one flexibilizer comprising reactive functional groups selected from epoxy groups, carboxylate groups, amino groups and/or hydroxyl groups;
(d) 1 to 4 wt % of at least one cationic photoinitiator;
(e) a co-toughener in an amount of 0.1-10 wt %; and/or
(f) a reactive diluent in an amount of 0.1-10 wt %; and/or
(g) an adhesion promoter selected from chelate-modified epoxy resins and epoxy-modified silanes in an amount of 0.1-3 wt %, characterized in that the at least one flexibilizer comprises epoxy groups.

2. The photocurable epoxy resin composition as claimed in claim 1 , characterized in that the core-shell rubbers are selected from those that have a core formed of polybutadiene and a shell formed of polybutadiene, polystyrene or a polybutadiene-polystyrene copolymer, wherein the core-shell rubbers are optionally dispersed in a matrix, wherein the matrix is selected from aromatic epoxy resins.

3. The photocurable epoxy resin composition as claimed in claim 1 , characterized in that the at least one flexibilizer is a polymer or an oligomer having a glass transition temperature of less than 20° C.

4. The photocurable epoxy resin composition as claimed in claim 1 , characterized in that the at least one flexibilizer is selected from the group consisting of polytetramethylene ether glycol, polycaprolactone diol or triol, cardanol glycidyl ethers and dicarboxylic acid bis((3,4-epoxycyclohexyl)methyl) esters.

5. A photocurable epoxy resin composition comprising:
(a) 30 to 90 wt % of at least one aromatic epoxy resin;
(b) 2 to 30 wt % of at least one core-shell rubber as toughener;
(c) 1 to 20 wt % of at least one flexibilizer comprising reactive functional groups selected from epoxy groups, carboxylate groups, amino groups and/or hydroxyl groups;
(d) 1 to 4 wt % of at least one cationic photoinitiator;
(e) a co-toughener in an amount of 0.1-10 wt %; and/or
(f) a reactive diluent in an amount of 0.1-10 wt %; and/or
(g) an adhesion promoter selected from chelate-modified epoxy resins and epoxy-modified silanes in an amount of 0.1-3 wt %, characterized in that the photoinitiator is selected from sulfonium salts and iodonium salts, wherein the counterion is selected from hexafluoroantimonate, hexafluorophosphate and (tetrakis(pentafluoroaryl)borates.

6. A photocurable epoxy resin composition comprising:
(a) 30 to 90 wt % of at least one aromatic epoxy resin;
(b) 2 to 30 wt % of at least one core-shell rubber as toughener;
(c) 1 to 20 wt % of at least one flexibilizer comprising reactive functional groups selected from epoxy groups, carboxylate groups, amino groups and/or hydroxyl groups;
(d) 1 to 4 wt % of at least one cationic photoinitiator;
(e) a co-toughener in an amount of 0.1-10 wt %; and/or
(f) a reactive diluent in an amount of 0.1-10 wt %; and/or
(g) an adhesion promoter selected from chelate-modified epoxy resins and epoxy-modified silanes in an amount of 0.1-3 wt %, , characterized in that the reactive diluent is selected from monoglycidyl ethers of aliphatic or aromatic alcohols.

7. The photocurable epoxy resin composition as claimed in claim 1 , characterized in that the co-toughener is a polyether polyol.

8. A process for sealing metal-containing electrical lines or contacts for protection against electrochemical corrosion, comprising the steps of:
(i) applying in the form of a film the photocurable epoxy resin composition as claimed in claim 1 to metal-containing electrical lines or contacts; and
(ii) curing the film by exposure to light.

9. The photocurable epoxy resin composition as claimed in claim 1 , characterized in that the aromatic epoxy resin is selected from bisphenol A diglycidyl ethers and bisphenol F diglycidyl ethers.

10. The photocurable epoxy resin composition as claimed in claim 1 , characterized in that the aromatic epoxy resin comprises diglycidyl ethers of bisphenol A, F and/or S, or epoxy novolacs.

11. A photocurable epoxy resin composition comprising:
(a) 30 to 90 wt % of at least one aromatic epoxy resin;
(b) 2 to 30 wt % of at least one core-shell rubber as toughener;
(c) 1 to 20 wt % of at least one flexibilizer comprising reactive functional groups selected from epoxy groups, carboxylate groups, amino groups and/or hydroxyl groups;
(d) 1 to 4 wt % of at least one cationic photoinitiator;
(e) a co-toughener in an amount of 0.1-10 wt %; and/or
(f) a reactive diluent in an amount of 0.1-10 wt %; and/or
(g) an adhesion promoter selected from chelate-modified epoxy resins and epoxy-modified silanes in an amount of 0.1-3 wt %, characterized in that the reactive diluent is selected from monoglycidyl ethers of C12/C14 fatty alcohols and alkyl phenols.

12. A photocurable epoxy resin composition comprising:
(a) 30 to 90 wt % of at least one aromatic epoxy resin;
(b) 2 to 30 wt % of at least one core-shell rubber as toughener;
(c) 1 to 20 wt % of at least one flexibilizer comprising reactive functional groups selected from epoxy groups, carboxylate groups, amino groups and/or hydroxyl groups;
(d) 1 to 4 wt % of at least one cationic photoinitiator;
(e) a co-toughener in an amount of 0.1-10 wt %; and/or
(f) a reactive diluent in an amount of 0.1-10 wt %; and/or
(g) an adhesion promoter selected from chelate-modified epoxy resins and epoxy-modified silanes in an amount of 0.1-3 wt %, characterized in that the reactive diluent is selected from monoglycidyl ethers of para-tert-butyl phenol.

Assignees

• Henkel Ag & Co Kgaa

Inventors

• Hagenbucher Melanie
• Hornung Martin

Classifications

• B05D3/067

  Curing or cross-linking the coating · CPC title

• B05D2504/00

  Epoxy polymers · CPC title

• C08L63/00 Primary

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

• B05D2202/00

  Metallic substrate · CPC title

• C23F15/00

  Other methods of preventing corrosion or incrustation · CPC title