Abstract: A method of joining narrow waterproof sheets to obtain a waterproof sheet of wide width having a gently curved joint which is free from any acutely stepped portion. It comprises disposing a cure tape between the overlapping edge portions of the sheets to be joined, positioning a piece of cushiony material below or above the overlapping edge portions, and heating the overlapping edge portions and the cure tape under pressure. The cure tape has a width which is substantially equal to that of the overlapping edge portions before pressure is applied thereto. When pressure is applied, the cure tape projects in opposite directions beyond the extremities of the overlapping edge portions. One form of the joint thus formed is flat on one surface and gently curved on the other surface, while another form is gently curved on both surfaces thereof.

Abstract: An acrylic copolymer vulcanizate, which is a sulfur-vulcanized product of an acrylic copolymer, the acrylic copolymer being obtained by the radical polymerization of a monomeric mixture consisting essentially of 100 parts by weight of at least one acrylic acid ester of an aliphatic alcohol containing 1 to 8 carbon atoms and about 1 to about 15 parts by weight of a 5-substituted-2-norbornene of the general formula ##STR1## wherein R represents .dbd.CH--CH.sub.2).sub. x CH.sub.3, in which x is 0 to 4, or --CH.dbd.CH.sub.2, in the presence of about 0.05 to about 3.0 parts by weight, per 100 parts by weight of the monomeric mixture, of a sulfur vulcanization accelerator which does not cause degradative chain transfer.

Abstract: An acrylic copolymer composition capable of being vulcanized with sulfur comprising the radical polymerization product of (1) a monomer mixture comprising an acrylic acid ester and ethylidene norbornene, (2) a monomer mixture comprising an acrylic acid ester, ethylidene norbornene and acrylonitrile, (3) a monomer mixture comprising an acrylic acid ester and vinyl norbornene, or (4) a monomer mixture comprising an acrylic acid ester, vinyl norbornene and at least one unsaturated compound selected from the group consisting of monovinyl compounds, monovinylidene compounds and monovinylene compounds.

Abstract: This invention involves manufacturing a conveyor belt by applying tension on a group of steel cords used as the belt tensile member, wrapping the tensioned steel cords with the rubber sheet to make a core body, sticking a based duck or a breaker and a covering rubber sheet in turn on said core body to build a belt, vulcanizing the belt and winding the resultant belt, in which the application of the tension to the group of steel cords is carried out by a plurality of pulleys on which hang a plurality of like weights respectively, and a winder.