Alloys used as matrix materials for composites or as moulding materials - contains cycloolefin and polyacetal copolymers and are of at least two components

Polymer alloys of at least 2 components are claimed (I), contg. (A) 1-99 wt.% cyclo-olefin copolymer(s) and (B) 99-1 wt.% polyacetal. (A) contains units derived from monomer(s) (IIA-IIF) or (III); R1-R8 = H or 1-8C alkyl; n = 2-10. (A) is modified by grafting with (a) alpha, beta-unsatd. acid (derivs.), (b) styrenes, (c) unsatd. organo-Si cpds. with hydrolysable gps. and/or (d) unsatd. epoxides; in addn. to monomer units as above, (A) contains other units derived from acyclic olefin(s) of formula R9R11C=CR10R12 (V) (with R9-R12 = H or 1-8C alkyl); (A) is a copolymer of monomers (IIA) or (IIC) and monomer (V), pref. a norbornene/ethylene copolymer; (B) contains 80-100 (pref. 99.5-95) wt.% units of formula -(CH2O)-, and pref. 0.5-5 wt.% other units derived from (e) 3-, 4- or 5-membered cyclic ethers, (f) 5- to 11-membered cyclic acetals other than tri- or tetra-oxan or (g) linear polyacetals; pref., (A) is a copolymer with units of formula -CH2CH2- and (IV), and (B) is a copolymer with units of formula -(CH2O)- and -(CH2CH2O)-; pref., (I) also contains a polymer (A) modified by grafting as above, esp. with maleic anhydride. USE/ADVANTAGE - (I) are useful as matrix materials for composites or for the prodn. of moulded prods. (claimed). The invention provides alloys of cyclo-olefin polymers and polyacetals with improved melt flow properties, improved mechanical properties and reduced water absorption.