TH8131A - The polypropylene polymer composition has good transparency and has also improved the impact resistance. - Google Patents

Abstract

The best transparent polypropylene polymer composition It was also improved low temperature impact resistance consisting of (a) 70-80% by weight of crystalline ethylene-propylene copolymer / or with alpha-O. The lefin of the formula H2C = HCR, where R is a linear or branched alkyl group of C2-8 and (b) 2-30% by weight of elastomeric propylene. - Ethylene copolymer by part of the copolymer (b) soluble in xylene at room temperature has a limited viscosity (IV2.) Corresponding to the following relationship. 0.2 <-( IV2 / IV1) x (C2) < -0.6 where IV1 is the limiting viscosity of the crystalline propylene copolymer, (C2) is the volume by weight of Ethylene's (b) The volume-by-weight ratio of ethylene (b) and the weight of the xylene dissolved fraction is equal or less than 1.5. The composition can be prepared by polymerization. Rank the monomers with a specific stereo catalyst, zigler-natta. This includes titanium compounds backed by magnesium dihelide in a reactive manner.

Claims (4)

1.Polymer composition Containing a) 70-98% by weight of propylene and ethylene copolymer crystals and / or with CH2 = CHR alpha olefin, where R is the derivative. Straight-chain or branched alkyl with 2-8 carbon atoms, 85-99.5% by weight of polypropylene and 0.5 to 10% by weight of ethylene and / or alpha olefin. b) 2-30% by wt. of ethylene and propylene elastomer elastomer and / or CH2 = CHR olefins available from 20-70% by Ethylene weight Where elastomeric copolymer It will partially dissolve in xylene at room temperature. It is also characterized by the fact that the volume-by-weight ratio of ethylene contained in such elastomeric polymers. And the weight of elastomeric polymers dissolved in xylene was equal to or less than 1.5, while having a limited viscosity (IV2.) Of the dissolved part of the xylene. Correspond to the following relationship 0.2 < = (I.V.2 / I.V.1) x (C2) < = 0.6, where I.V. 1. is the limiting viscosity of the crystalline propylene copolymer a). 1.and I.V. 2. is dl / g, and (C2) is the ethylene weight ratio of the lastomeric copolymer b). 2. The polymer composition of claim 1 containing 80-95% by weight of crystalline polypropylene copolymer a) consisting of 90-98% by weight of polypropylene and from 1-5% by weight of ethylene and 5-20% by weight of elastomeric copolymer b) which is from 25-60% by weight of ethylene. 3. The composition of the claim 1 or 2, where% by weight of the solute in xylene at room temperature is between 10 and 25% and the ratio of ethylene in elastomeric weight. The copolymer and the weight of the aqueous fraction are between 0.3 and 1.5. 4. The process of preparing any one to three claim elements Where it is initially polymerized, a mixture of propylene and ethylene and / or CH2 = CHR alphaolefin, where R has the above meaning. With a catalog that is stereospecific catalyst) supported by magnesium dihelide in a reactive manner. In order to obtain such a crystalline propylene copolymer a) and where in step 2 the ethylene-propylene mixtures and / or CH2 = CHR alpha olifin to obtain elastomeric Ethylene copolymer b) with a catalyst used in the first step And will get the said polymer out