Stabilised oxymethylene! polymer moulding compsn. - contg. dispersion of polyamide particles in carrier resin, reducing deposits during moulding

摘要

A stabilised moulding and press compsn. contains (a) an oxymethylene polymer, and (b) a dispersion of (A) a polyamide in (B) a carrier resin. The polyamide is in the form of particles of is not >5 mu (is not 2 mu). The m.pt. of the semi-crystalline polyamide, or the glass transition temp. (Tg) of the amorphous polyamide, is above the m.pt. of the oxymethylene polymer. The polymer chain consists of -(CH2-O)n-units, where n is not 500, and may contain 40% (5%) of units of formula (R1-C-R2)m, where m=1-5 and R1 and R2 are inert substits. The m.pt.m of the semi-crystalline polyamide is pref. >200 degrees C (>240 degrees C), and is not 25 degrees C above the m.pt. of the oxymethylene polymer. For amorphous polyamides the Tg is pref. is not 5 degrees C above the m.pt. of the oxymethylene polymer. The degree of polymerisation is esp. 50-500. The polyamide contains units of formula where R is pref. H, alkyl or alkoxy. The dispersion partic. contains 10-50 (25-40) wt.% of polyamide. Carrier resins include ethylene (co)polymers etc.