Composite structures having improved heat aging and interlayer bond strength

Abstract

Disclosed herein are composite structures having improved heat aging, processes for making them, and end use articles. The composite structures comprise a polyamide matrix resin composition comprising a matrix heat stabilizer ; a fibrous material and a polyamide surface resin composition comprising copper based heat stabilizer; wherein: the matrix heat stabilizer is different than the copper based heat stabilizer; and wherein the fibrous material is impregnated with the polyamide matrix resin composition.

Description

CROSS REFERENCE TO RELATED APPLICATIONS[0001]The present application claims the benefit of U.S. Provisional Application No. 61 / 408,166, filed Oct. 29, 2010, which is now pending, the entire disclosure of which is incorporated herein by reference; and U.S. Provisional Application Nos. 61 / 410,093, filed Nov. 4, 2010; 61 / 410,100, filed Nov. 4, 2010; 61 / 410,104, filed Nov. 4, 2010; and 61 / 410,108, filed Nov. 4, 2010; all of which are now pending, the entire disclosures of which are incorporated herein by reference.FIELD OF THE INVENTION[0002]The present invention relates to the field of composite structures having improved heat aging, processes for making them, and end use articles.BACKGROUND OF THE INVENTION[0003]With the aim of replacing metal parts for weight saving and cost reduction while having comparable or superior mechanical performance, structures based on composite materials comprising a polymer matrix containing a fibrous material have been developed. With this growing inter...

AI Technical Summary

Benefits of technology

[0018]However, there is still a need for a composite structure comprising a matrix resin composition that can rapidly and efficiently impregnate a fibrous material and wherein the composite structure exhibits good long-term heat stability.

Problems solved by technology

However, the use of a low melt viscosity polyamide composition for improving or accelerating the mixing or impregnation of fibrous materials may lead to composite structures that are not ideal for highly demanding applications such as the automotive field due to inferior mechanical and heat aging properties.

The addition of heat stabilizers to polymer matrix compositions can allow for a higher impregnation temperature which lowers the viscosity of the polymer matrix composition but these heat stabilizers can also interfere with adhesion of the overmolding resin.