Epoxy compositions having improved impact resistance
View Patent ↗This invention relates to compositions useful as adhesives and more particularly to the preparation of heat-cured epoxy-based adhesive compositions with improved impact resistance and good adhesion to oily metal substrates.
1. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activiated latent curing agent;
additionally comprising at least one filler selected from the group consisting of platy fillers, hollow glass microspheres and combinations thereof.
2. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
additionally comprising at least one chelate-modified epoxy resin.
3. A composition of comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
comprising from about 0.1 to about 3 weight percent of at least one chelate-modified epoxy resin.
4. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
comprising at least one substituted guanidine heat-activated latent curing agent.
5. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
wherein said rubber particles have an average diameter of from about 25 to about 200 nm.
6. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
wherein the weight ratio of epoxy resin:combined weight of auxiliary impact modifier/toughener and rubber particles having a core-shell structure is from about 0.2:1 to about 3:1.
7. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
wherein the weight ratio of auxiliary impact modifier/toughener:rubber particles is from about 0.2:1 to about 5:1.
8. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
additionally comprising at least one reactive diluent which is a mono-epoxide.
9. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
comprising from about 25 to about 55 weight percent epoxy resin, from about 5 to about 40 weight percent auxiliary impact modifier/toughener, and from about 5 to about 25 weight percent rubber particles having a core-shell structure, wherein the weight ratio of epoxy resin:combined weight of auxiliary impact modifier/toughener and rubber particles having a core-shell structure is from about 0.2:1 to about 3:1 and the weight ratio of auxiliary impact modifier/toughener:rubber particles is from about 0.2:1 to about 5:1.
10. A composition comprising:
A) at least one epoxy resin;
B) rubber particles having a core-shell structure;
C) at least one auxiliary impact modifier/toughening agent;
D) at least one heat-activated latent curing agent;
wherein at least a portion of the rubber particles having a core-shell structure have an average diameter of from about 25 to about 200 nm and are stably dispersed in a masterbatch comprised of epoxy resin when combined with the other components of the composition, with said rubber particles having a core comprised of a polymer or copolymer of 1,4-butadiene having a glass transition temperature of not greater than −40° C.