Stabilized oxymethylene copolymer composition

#The invention relates to a novel stabilized oxymethylene copolymer composition. More particularly, the present invention relates to an oxymethylene copolymer composition which is superior to conventional oxymethylene copolymer compositions in long-term stability. In particular, the oxymethylene copolymer composition of the present invention is superior in long-term hot water resistance and long-term heat ageing characteristics and forms only a very small amount of a deposit on a mold at the time of molding.

#Oxymethylene copolymers are plastics which are widely utilized as engineering resins in various fields because these plastics have excellent mechanical characteristics, moldability, etc.

#However, unstabilized oxymethylene copolymers are insufficient in stability and hence are disadvantageous, for example, in that oxymethylene copolymer undergo depolymerization at the terminals or undergo severance of the main chain under a high temperature atmosphere or in hot water. Therefore, oxymethylene copolymers should usually be stabilized by various terminal treatments followed by the addition of additives such as antioxidants, thermostabilizers, etc.

#The present invention is further illustrated in more detail with reference with the following examples.

#Characteristics of compositions in Examples and Comparative Examples are evaluated as follows:

#A 120.degree. C. long-term hot water resistance test is carried out by means of an autoclave having a pressure regulating valve. Deionized water is used as test water. A temperature control unit and a flowmeter are set, and the test is carried out by a 120.degree. C. flowing water method.