Composite ballistic resistant laminate

Patent metadata

Field	Value
Publication number	US-2016243790-A1
Application number	US-201615133283-A
Country	US
Kind code	A1
Filing date	Apr 20, 2016
Priority date	Feb 18, 2015
Publication date	Aug 25, 2016
Grant date	—

Abstract

An unconsolidated impact and penetration resistant laminate comprises a plurality of cross-plied sheets, each cross-plied sheet further comprising (i) first and second layers of fibrous or non-fibrous ultra-high molecular weight polyethylene and (ii) first and second layers of thermoplastic adhesive, each adhesive layer having a basis weight of no greater than 5 gsm, wherein
(a) the layers of polyethylene and thermoplastic adhesive alternate within the sheet, (b) at least 50 percent of the polyethylene layers are arranged such that the orientation of the first polyethylene layer is offset with respect to the orientation of the second polyethylene layer, and (c) the plurality of cross-plied sheets form a stack that, when subjected to compaction at a pressure of 255 bar and a temperature of 132 degrees C., will not suffer a pressure loss greater than 8 bar within the first two minutes as measured by Test Method B.

First claim

What is claimed is:

1 . An unconsolidated impact and penetration resistant laminate comprising a plurality of cross-plied sheets, each cross-plied sheet further comprising (i) first and second layers of fibrous or non-fibrous ultra-high molecular weight polyethylene and (ii) first and second layers of thermoplastic adhesive, each adhesive layer having a basis weight of no greater than 5 gsm, wherein
(a) the layers of polyethylene and thermoplastic adhesive alternate within the sheet, (b) greater than 50 percent of the polyethylene layers are arranged such that the orientation of the first polyethylene layer is offset with respect to the orientation of the second polyethylene layer, and (c) the plurality of cross-plied sheets form a stack that, when subjected to compaction at a pressure of 255 bar and a temperature of 132 degrees C., will not suffer a pressure loss greater than 8 bar within the first two minutes as measured by Test Method B.

2 . The laminate of claim 1 in which the thermoplastic adhesive has a zero shear rate viscosity, determined by Test Method A, of at least 1500 Pa s.

3 . The laminate of claim 1 wherein the thermoplastic adhesive further comprises a thixotrope.

4 . The laminate of claim 1 wherein the first and second polyethylene layers within a cross-plied sheet have an orientation that is essentially orthogonal to each other.

5 . The laminate of claim 2 wherein the thermoplastic adhesive has a zero-shear-rate viscosity of at least 10,000 Pa-s.

6 . The laminate of claim 3 wherein the thixotrope is an inorganic particle.

7 . The laminate of claim 3 wherein the thixotrope is a dendritic polymeric particle.

8 . The laminate of claim 5 wherein the thermoplastic adhesive has a zero-shear-rate viscosity of at least 100,000 Pa-s.

9 . The laminate of claim 8 wherein the thermoplastic adhesive has a zero-shear-rate viscosity of at least 1,000,000 Pa-s.

10 . The material of claim 1 , in which the polyethylene is in the form of nonfibrous sheets or films.

Assignees

• Du Pont

Inventors

• Singletary James Neal
• Carbajal Leopoldo Alejandro
• Kampert William George
• Libert Timothy A
• Sauer Bryan Benedict
• Harding Kenneth C

Classifications

• B32B2250/05

  5 or more layers · CPC title

• B32B2255/10

  on synthetic resin layer or on natural or synthetic rubber layer · CPC title

• B32B2255/26

  Polymeric coating · CPC title

• B32B2571/02

  defensive, e.g. armour plates or anti-ballistic clothing · CPC title

• B32B27/32

  comprising polyolefins {(comprising vinyl (co)polymers or acrylic (co)polymers B32B27/30)} · CPC title