Patent ID: 6207758
Filing Date: 2001-03-27
Classification: C08F,C08L

Abstract:
A composition containing fluorinated thermoplastic elastomers with different molecular weights and with different plastomeric phase/elastomeric phase ratios, said composition having a dynamic viscosity determined by rheogoniometer RMS.RTM. 800 (Frequency sweep, frequency of 10.sup.-2 radiants/sec, parallel plates) lower than 10.sup.7 poise and Melt Flow Index (MFI), determined according to the ASTM D 1238-52T standard with a 5 Kg load, greater than 1 (g/10 minutes), consisting essentially of:(a) 30-80% by weight of a fluorinated thermoplastic elastomer having a block structure A-B-A, wherein A is a plastomeric segment and B is an elastomeric segment, in which:at least one block is formed by a fluorinated elastomer and at least one block by a fluorinated plastomer;the elastomeric segment B having a Mooney viscosity greater than 10;the amount of plastomeric phase A is between 5 and 40% by weight;the MFI of the thermoplastic elastomer is less than 0.1;(b) 10-50% by weight of a fluorinated thermoplastic elastomer having a block structure of A-B-A, wherein A and B are as defined above, in which:there is at least a fluorinated elastomeric segment and at least a fluorinated plastomeric segment;the elastomer B has a Mooney viscosity less than 5;the plastomeric phase A is between 2 and 20% by weight;the MFI of the thermoplastic elastomer (b) is greater than 100;(c) 0-30% by weight of a fluorinated plastomer having an MFI value greater than 1.