GB1106342A - Water impervious sheet material - Google Patents

Abstract

1,106,342. Laminates. PERMANITE Ltd. 10 May, 1965 [14 April, 1964], No. 15433/64. Heading B5N. A sheet or strip material comprises a basic flexible sheet or strip of either a fibre based felt formed wholly or mainly of animal and/or vegetable fibres or formed wholly or mainly of asbestos fibres, impregnated and coated on at least one face with bitumen, coal tar pitch or asphalt which is substantially non-adhesive at normal or atmospheric temperatures, or of glass fibre tissue coated on at least one face with a bitumen, coal tar pitch or asphalt which is substantially non-adhesive at normal or atmospheric temperatures, characterized by an additional layer on one of the faces of the coated or coated and impregnated sheet or strip of a stabilized self-adhesive bitumen capable of adhesion cold or at normal atmospheric temperatures and a cover sheet or strip of release material applied over the external face of the stabilized self-adhesive layer. The stabilized bitumen may form a continuous or discontinuous layer and may be applied to the coated or non-coated surface of the felt or tissue. In a modification of the invention, granular material e.g. gravel is applied to the coated surface of the felt or tissue prior to the application thereto of the stabilized bitumen layer. Specified stabilizers for the bitumen layer are short fibres of cow and goat hair, jute, flax and ground asbestos. In Fig. 1, strip 10 is drawn through tank 11 containing impregnant, between rollers 13 (these steps being omitted for a glass fibre tissue strip), over transfer coating roller 15, optionally over transfer coating roller 16, past transfer roller 21 where stabilized bitumen is applied, a layer of release paper 25 then being applied to the stabilized bitumen layer.