Blow-moulded or injection-moulded polypropylene@ mouldings with balance stiffness and heat distortion temperature

摘要

Blow-moulded or injection-moulded polyolefin mouldings with improved heat distortion temperature and stiffness comprise: (a) 60-99.9, preferably 75-98 wt.% unmodified polypropylene polymer (I) and (b) 40-0.1, preferably 25-2 wt.% modified propylene polymer (B). (I) consists of (a1) usual propylene polymers, preferably homopolymers produced using Ziegler-Natta or metallocene catalyst, especially with a weight/number average molecular weight ratio Mw/Mn of 2-4.5, and/or random, block and/or random block copolymers of 80.0-99.9 wt.% propylene with ethylene and/or 4-18 carbon (C) alpha -olefins with a melt index (MI; g/10 min at 230 deg C/2.16 kg) = 0.1-300, preferably 1-100,; (a2) a polyolefin mixture, with Mw/Mn = 2-6 and MI = 1-40, of (a2.1) 60-98 wt.% crystalline copolymer of 85-99.5 wt.% propylene and 15-0.5 wt.% ethylene and/or alpha -olefin of the formula CH2=CHR (R = linear or branched 2-8 alkyl); (a2.2) 2-40 wt.% elastic copolymer of 20-70 wt.% ethylene and 80-30 wt.% propylene and/or CH2=CHR; (a3) amorphous (co)polypropylene containing 0-20 wt.% CH2=CHR, with 10 wt.% crystalline fraction with a melt enthalpy 40 J/g and MI = 0.1-100; (a4) non-isotactic homopolypropylene with a melting point of 145-165 deg C, heat of crystallisation of 4-10 cal/g and 35-55 wt.% soluble fraction in diethyl ether. (I) contains 0.01-2.5 wt.% stabiliser, 0.01-5 wt.% processing aid and optionally 0.1-1 wt.% antistatic, 0.2-3 wt.% pigment, 0.05-1 wt.% nucleating agent, 2-20 wt.% flame retardant as ancillaries and/or 3-40 wt.% (in)organic filler(s) and/or reinforcement(s) with respect to (I). The novel features are that (i) (II) is a modified homo- and/or co-polymer with MI = 0.05-40, preferably 0.25-15 and the ratio of the intrinsic viscosity of (II) to that of the unmodified polymer of the same Mw on which it is based is 0.20-0.95; and (ii) (II) is produced by (b1) modifying homopolypropylene and/or copolymers of propylene and ethylene and/or 4-18 C alpha -olefins with polyfunctional ethylenically unsaturated monomers and/or with ionising radiation or thermal free radical initiators; (b2) reacting functionalised polypropylene, preferably containing acid and/or acid anhydride groups, with polyfunctional compounds of opposite reactivity, preferably 2-16 C diamines ad/or 2-16 C diols; and/or (b3) hydrolytic condensation of polypropylene containing hydrolysable silane groups. Also claimed is a method of making the mouldings.