Ductile one-component thermosetting epoxy composition

Patent metadata

Field	Value
Publication number	US-11447599-B2
Application number	US-202117208732-A
Country	US
Kind code	B2
Filing date	Mar 22, 2021
Priority date	Mar 20, 2020
Publication date	Sep 20, 2022
Grant date	Sep 20, 2022

Abstract

A one-component thermosetting epoxy resin composition, including a) at least one epoxy resin A having on average more than one epoxide group per molecule; b) at least one latent hardener for epoxy resins; c) at least one physical or chemical blowing agent BA; d) 3-15 wt.-% of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR1 with a Mooney Viscosity of 15-30 MU (Mooney units), based on the total amount of epoxy resin A; and e) 3-15 wt.-% of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR2 with a Mooney Viscosity of 35-50 MU (Mooney units), based on the total amount of epoxy resin A. The ratio of ABR1 to ABR2 is from 0.5-2.0. The epoxy resin adhesive is notable for the improved storage stability.

First claim

The invention claimed is:

1. A one-component thermosetting epoxy resin composition, comprising
a) at least one epoxy resin A having on average more than one epoxide group per molecule;
b) at least one latent hardener for epoxy resins; and
c) at least one physical or chemical blowing agent BA; and
d) 3-15 wt.-%, of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR1 with a Mooney Viscosity (ML 1+4 at 100° C.) of 15-30 MU (Mooney units), based on the total amount of epoxy resin A; and
e) 3-15 wt.-%, of at least one carboxyl group containing acrylonitrile/butadiene rubber ABR2 with a Mooney Viscosity (ML 1+4 at 100° C.) of 35-50 MU (Mooney units), based on the total amount of epoxy resin A,
wherein the ratio of ABR1 to ABR2 is from 0.5-2.0.

2. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the fraction of the epoxy resin A having on average more than one epoxide group per molecule is from 30-90 wt %, based on the total weight of the one-component thermosetting epoxy resin composition.

3. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the epoxy resin A is a solid epoxy resin.

4. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the carboxyl group containing acrylonitrile/butadiene rubbers ABR1 and ABR2 have a carboxyl content of 0.005 equivalents per hundred rubber (EPHR) to 0.4 EPHR.

5. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the carboxyl group containing acrylonitrile/butadiene rubbers ABR1 and ABR2 include from 20% -40% by weight nitrile.

6. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the ratio of ABR1 to ABR2 is from 0.8-1.25.

7. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the latent hardener is selected from dicyandiamide, guanamines, guanidines, aminoguanidines and derivatives thereof, substituted ureas, imidazoles and amine complexes.

8. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the one-component thermosetting epoxy resin composition further comprises at least one filler F, selected from the group consisting of calcium carbonate, calcium oxide, talc, glass fibres and fumed silicas.

9. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the proportion of the blowing agent BA is 0.1-5% by weight, based on the total weight of the epoxy resin composition.

10. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the one-component thermosetting epoxy resin composition has a melt flow index (MFI) of 0.5-15 g/10 min, determined at 110° C., 2.16 kg in accordance with ASTM D1238.

11. The one-component thermosetting epoxy resin composition according to claim 1 , wherein the one-component thermosetting epoxy resin composition is tack-free at 23° C.

12. A reinforcement element comprising the one-component heat-curing epoxy resin composition according to claim 1 for reinforcement in the cavities of structural components.

13. A method for reinforcing structural components comprising the steps
i) placing a reinforcement element according to claim 12 in a cavity of a structural component;
ii) heating the reinforcement element to a temperature from 120° C. to 220° C., for 10 to 60 min.

Assignees

• Sika Tech Ag

Inventors

• Bordeanu Nicolae
• Wolschleger Leslie

Classifications

• C08G59/245 Primary

  aromatic · CPC title

• C08J9/0066

  Use of inorganic compounding ingredients · CPC title

• C08J9/0028

  containing nitrogen · CPC title

• C08L13/00

  Compositions of rubbers containing carboxyl groups · CPC title

• C08J9/105

  containing sulfur · CPC title