US 4,443,511 A · Elastomeric waterproof laminate

Abstract

This invention provides a waterproof and breathable elastomeric polytetrafluoroethylene layered article for use in, for example, material for protective articles. The waterproof and breathable polytetrafluoroethylene layered article can for example, exhibit elastomeric properties of stretch to break of 275% in the machine direction, and 145% in the transverse direction and a total stretch recovery of at least 39% after being stretched to 75% extension for 100 cycles. This invention further provides a waterproof and breathable elastomeric polytetrafluoroethylene layered article bonded to a stretch fabric. The waterproof and breathable elastomeric polytetrafluoroethylene layered article bonded to a stretch fabric is thus durable and possesses a moisture vapor transmission rate exceeding 1000 gms/m.sup.2 day, and preferably above about 2000 gms/m.sup.2 day.

Claims18

Dependent claims

A process for forming a stretchable composite article having at least two layers comprising the steps of:

(i) mechanically stretching the composite to impart stretch and recovery properties thereto, said layers comprising:
(a) a first layer of hydrophobic material having a moisture vapor transmission rate exceeding 1000 gma/m.sup.2 day and an advancing water contact angle exceeding 90 degrees;
and
(b) an elastomeric hydrophilic layer having a major portion of one surface in interlocking relationship with the inner face of said first layer, said hydrophilic layer having moisture vapor transmission rate exceeding 1000 gms/m.sup.2 day, the stretching step extending the first layer in one direction at least 5% beyond its yield point;
and
(ii) relaxing the stretched composite.

3 more elements

Dependencies are inferred from the claim text.

Elastomeric waterproof laminate

Life of this patent

Elastomeric waterproof laminate

Life of this patent

Abstract

Claims18