摘要:
The present invention describes an elastic article comprising at least one low crystallinity polymer layer and optionally a high crystallinity polymer layer. The low crystallinity polymer layer comprises a low crystallinity polymer and optionally an additional polymer. The optional high crystallinity polymer layer comprises a high crystallinity polymer having a melting point within about 50° C. of the melting point of the low crystallinity polymer. The article is elongated at a temperature below the melting point of the low crystallinity polymer and the optional high crystallinity polymer in at least one direction to an elongation of at least about 50% of its original length or width. Subsequently, the article may be heat-shrunk at a temperature not greater than 10° C. above the melting point of the low crystallinity polymer.
摘要:
The present invention includes a polyolefin elastomeric composition comprising a propylene-based elastomer having at least seventy five weight percent units derived from propylene, the propylene-based elastomer exhibiting a heat of fusion of from 1 to 35 Joules/gram, a weight average molecular weight of from 5400 to 875000 g/mol, and a permanent set of less than 40%; and a homogeneous ethylene-alpha olefin interpolymer having a molecular weight distribution of less than 3.5, a density from 0.885 to 0.915 g/ml, and a heat of fusion of from 65 to 125 Joules/gram, wherein the ratio of the propylene-based elastomer to the homogeneous ethylene-alpha olefin interpolymer is from 97:3 to 80:20, and wherein the composition exhibits a heat of fusion from 2 to 55 Joules/gram, and a 2% secant flexural modulus of less than 69 MPa.
摘要:
Fibers that exhibit good elasticity or extensibility and tenacity, and low modulus are prepared from propylene-based copolymers. The propylene-based copolymers comprise at least about 50 weight percent (wt %) of units derived from propylene and at least about 8 wt % of units derived from one or more comonomers other than propylene, e.g., ethylene. Particularly preferred propylene copolymers are characterized as having 13C NMR peaks corresponding to a regio-error at about 14.6 and about 15.7 ppm, the peaks of about equal intensity. In one aspect of the invention, fibers are subjected to stress-induced crystallization by subjecting the fiber to tensile elongation during draw.
摘要翻译:表现出良好的弹性,伸长性和韧性以及低模量的纤维由丙烯基共聚物制备。 基于丙烯的共聚物包含至少约50重量%(wt%)衍生自丙烯的单元和至少约8重量%的衍生自除丙烯以外的一种或多种共聚单体的单元,例如乙烯。 特别优选的丙烯共聚物的特征在于具有对应于约14.6和约15.7ppm的区域误差的大约相同强度的峰的13 C NMR峰。 在本发明的一个方面,纤维在拉伸过程中经受纤维的拉伸伸长而受到应力诱导的结晶。