GB1265953A - - Google Patents

Abstract

1,265,953. Coated products. W. R. GRACE & CO. 21 Feb., 1969 [23 Feb., 1968], No. 47390/71. Divided out of 1,265,952. Addition to 1,230,754. Heading B2E. [Also in Divisions B5 and El] A structure in the, form of a roll comprises a membrane of a waterproofing pressure-sensitive bituminous-rubber adhesive adhered to a sheet-like support of polyethylene or polypropylene, one face of the support being substantially more readily physically separable from the membrane than the other face, the membrane being at least 0.025cm (and usually not more than 0.6cm) thick and the support being at least 15cm wide. The differential separability of the two faces of the support may be obtained by formation of a silicone release coating on one face, usually the face that faces away from the centre of the roll, either before, during or after lamination with the membrane, such as by application to the membrane prior to rolling up of a dispersion of a curable silicone compound. The polyolefine support may be in the form of a film or woven or non-woven fabric or may be cellular. The rubber in the adhesive composition may be virgin or reclaimed natural or synthetic, the ratio by weight of bitumen to rubber usually being from 80:20 to 95:5. The support, especially when it comprises a woven fabric of polypropylene fibres, may have on its other surface a waterproof layer of a bitumen adhesive which is not pressure-sensitive when cold but becomes tacky at elevated temperatures. The structures, when unrolled, may be used to seal surfaces such as concrete, particularly in road-building, and a number of them may be overlapped to provide a continuous waterproof seal.