EPOXY RESIN COMPOSITION

Abstract

The present invention relates to adhesive compositions containing a prepolymer which can be obtained by reacting a reaction mixture containing: at least one epoxy resin; at least one polyetherdiamine or polyethertriamine; at least one carboxyl-terminated butadiene-acrylonitrile copolymer (CTBN); and rubber particles having a core/shell structure. The invention also relates to methods for curing said compositions, to the cured adhesive compositions thus obtained, to the use thereof for bonding components and to the components thus obtained.

Claims

1. An adhesive composition, comprising a prepolymer which can be obtained by reacting a reaction mixture containing: (a) at least one epoxy resin; (b) at least one polyetherdiamine or polyethertriamine, in particular polyethertriamine; (c) at least one carboxyl-terminated butadiene-acrylonitrile copolymer (CTBN); and (d) rubber particles having a core/shell structure.

2. The adhesive composition according to claim 1, characterized in that (a) the at least one epoxy resin is a polyepoxide, in particular a polyglycidyl ether; and/or (b) the at least one polyetherdiamine or polyethertriamine is an amino-terminated polypropylene oxide.

3. The adhesive composition according to claim 1, characterized in that the at least one carboxyl-terminated butadiene-acrylonitrile copolymer (CTBN) is used as a CTBN epoxy resin adduct.

4. The adhesive composition according to claim 1, characterized in that, in the reaction mixture for the prepolymer, the epoxy resin is used in such an amount that the epoxy groups are present in molar excess in relation to the sum of epoxy-reactive groups.

5. The adhesive composition according to claim 1, characterized in that the adhesive composition further contains a latent curing agent.

6. A method for producing a cured adhesive composition, which comprises: (a) providing an adhesive composition according to claim 1; and (b) partially or fully curing the adhesive composition through exposure to conditions suitable for curing the adhesive composition, in particular by heating.

7. A cured adhesive composition which can be obtained by the method according to claim 6.

8. The cured adhesive composition according to claim 7, characterized in that the cured adhesive composition (a) has a modulus of elasticity of <800, in particular <600 MPa; and/or (b) has a glass transition temperature T.sub.g of >100° C.

9. A method for bonding at least two components, which comprises: (a) applying an adhesive composition according to claim 1 to one or both of the components to be bonded; (b) bringing the components into contact such that the adhesive composition is located between the two components; and (c) partially or fully curing the adhesive composition through exposure to conditions suitable for curing the adhesive composition.

10. A component which can be obtained by the method according to claim 9.

Description

EXAMPLES

[0075] Procedure:

[0076] To prepare the composition E1 according to the invention, the first four components of the formulation were mixed and pre-reacted at 120° C. for 2 h in vacuo in a planetary mixer. All further constituents of the formulation were added to the resulting highly viscous prepolymer at 60° C., and mixing took place in vacuo for 30 min. For the comparative example V1, only the first two constituents were pre-reacted by the same method to obtain the prepolymer.

[0077] The modulus of elasticity was determined according to DIN EN ISO 527, and the TG was determined by means of DMA in accordance with ISO 6721-11. Suitable test specimens, as described in the standards, were prepared in PTFE molds by curing the adhesive formulations for 30 minutes at 180° C.

TABLE-US-00001 TABLE 1 Adhesive compositions (amounts specified in % by weight) E1 V1 DER331 epoxy resin (Dow Chemical) (1) 20.96 35 Jeffamine T5000 (Huntsman) (2) 21.8 16.5 Araldite LT 1522 ES (Huntsman) (3) 6.55 — Kane Ace MX-153 (Kaneka) (4) 32.34 30 Dyhard 100SH 4.55 5.7 Fenuron 0.3 0.3 Cab-o-Sil TS720 4.0 4.0 Casiflux A25 5.0 5.0 Glymo 0.5 0.5 Super 40 3.0 3.0 Luzenac 2 1.0 — E: according to the invention; V: comparative example

TABLE-US-00002 TABLE 2 Properties E1 V1 Young's modulus/MPa 460 880 T.sub.g (G” max)/° C. 112 122