Nova Patents
EP0504366B1

Microporous material

Abstract

This record has no abstract on file.

EP0504366B1, drawing sheet 1
Sheet 1 of 28

Term

Term ended

Expired 19 September 2011, 15 years ago.

  1. Priority
  2. Filed
  3. Granted
  4. Expired
  5. Today

16 claims: 14 independent, 2 dependent

  1. 1
    A microporous material which on a coating-free, printing ink-free, impregnant-free, and pre-bonding basis comprises:(a) a matrix comprising a mixture of substantially linear ultrahigh molecular weight polyethylene having an intrinsic viscosity of at least 10 deciliters/gram and lower molecular weight polyethylene having an ASTM D 1238-86 Condition E melt index of less than 50 grams/10 minutes and an ASTM D 1238-86 Condition F index of at least 0.1 gram/10 minutes;(b) finely divided substantially water-insoluble filler particles, of which at least 50 percent by weight are siliceous particles, said filler particles being distributed throughout said matrix;and (c) a network of interconnecting pores communicating substantially throughout said microporous material, said pores constituting from 35 to 80 percent by volume of said microporous material, wherein the weight percent of said ultrahigh molecular weight polyethylene (UHMWPE) in the total polyethylene of said matrix and the filler/matrix weight ratio are within the range defined by a polygon having the vertices: Vertix Weight % UHMWPE Filler/Matrix weight ratio A 1 0.5 B 3 3.1 C 47 2.5 D 47 2.0 E 60 2.0 F 60 0.5
  2. 2
    The microporous material of claims 1 wherein the weight precent of said ultrahigh molecular weight polyethylene in the total polyethylene of said matrix and the filler/matrix weight ratio are within the range defined by a polygon having the vertices:Vertix Weight % UHMWPE Filler/Matrix weight ratio G 10 0.5 H 10 3.0 C 47 2.5 I 47 0.5
  3. 4
    The microporous material of any of claims 1-3 wherein the intrinsic viscosity of said ultrahigh molecular weight polyethylene is at least 18 deciliters/gram.
  4. 5
    The microporous material of any of claims 1-3 wherein the intrinsic viscosity of said ultrahigh molecular weight polyethylene is in the range of from 18 to 39 deciliters/gram.
  5. 6
    The microporous material of any of claims 1-3 wherein said lower molecular weight polyethylene is high density polyethylene.
  6. 7
    The microporous material of any of claims 1-3 wherein said ultrahigh molecular weight polyethylene and said lower molecular weight polyethylene together constitute at least 65 percent by weight of the polymer of said matrix.
  7. 8
    The microporous material of any of claims 1-3 wherein said ultrahigh molecular weight polyethylene and said lower molecular weight polyethylene together constitute at least 85 percent by weight of the polymer of said matrix.
  8. 9
    The microporous material of any of claims 1-3 wherein the ultrahigh molecular weight polyethylene and the lower molecular weight polyethylene together constitute substantially 100 percent by weight of the polymer of said matrix.
  9. 10
    The microporous material of any of claims 1-3 wherein at least 85 percent by weight of said finely divided substantially water-insoluble filler particles are siliceous.
  10. 11
    The microporous material of any of claims 1-3 wherein substantially all of said finely divided substantially water-insoluble filler particles are siliceous.
  11. 12
    The microporous material of claims 1-3 wherein said siliceous particles are precipitated silica particles.
  12. 14
    The microporous material of any of claims 1-3 wherein said siliceous particles comprise clay particles.
  13. 15
    The microporous material of any of claims 1-3 wherein said substantially water-insoluble particles comprise titanium oxide particles.
  14. 16
    The microporous material of any of claims 1-3 wherein on a coating-free, printing ink-free, impregnant-free, and pre-bonding basis the volume average diameter of said pores as determined by mercury porosimetry is in the range of from 0.02 to 0.5 micrometers.
Independent claims14