The present invention relates to a polypropylene resin composition which is excellent in mechanical strength, especially rigidity at high temperature and breaking strength of a weld portion (which is a portion where molten resin which flows from two or more directions weld with each other) and which can give good appearance to a molded article.
Hitherto, various resin compositions have been proposed which have been improved in rigidity and heat resistance by incorporating fillers such as talc, mica, glass fiber and calcium carbonate in polypropylene resin, but these compositions are generally inferior in breaking strength of a weld portion as compared with that of a non-weld portion.
For instance, glass fiber-reinforced polypropylene resins (hereinafter referred to as "FRPP") are generally extremely inferior in impact strength, especially of a weld portion and besides, it is difficult to obtain molded articles of good appearance therefrom. Therefore, in many cases, these resins cannot be applied to instrument panels of cab internal parts or functional structural parts in the engine compartment of an automobile, though excellent heat resistance is exhibited.
USPTO Backgrounds
USPTO Backgrounds