GB1196071A - Production of Films. - Google Patents

Abstract

1,196,071. Films. FARBENFABRIKEN BAYER A.G. 4 Jan., 1968 [5 Jan., 1967], No. 648/68. Heading B5B. Films are produced by applying a soluble adhesive to a support, flocking the adhesivecoated support with fibrous flock, coating the dried flock with a high molecular weight plastics material and dissolving the soluble adhesive away after the plastics material has dried or gelled and then removing the support. The fibrous flock may be short fibres 0À3 to 3 mm. long or powdered fibre of, e.g. wool, cotton, rayon, polyester, polyamide or polyurethane and is applied by known flocking processes, e.g. by electrostatic means. The high molecular weight plastics material may be polyvinyl or polyvinylidene compounds, other polyolefines, polyamides, polyimides, polyurethanes, polyesters or rubber and may be applied or sprayed on to the flocked layer if desired from solution. The high molecular weight compound can also be formed in situ on the flocked layer from low molecular weight constituents, e.g. hydroxylcontaining polyesters, polyester amides and polyethers which yield high molecular weight polyurethanes when reacted with polyisocyanates. After drying, the soluble adhesive is dissolved out with water and a solvent, as a result of which the film can be lifted from the support. Soluble adhesives are natural or synthetic rubber latices, polymeric 2-chlorobutadiene, and copolymers of butadiene and acrylonitrile. Water soluble adhesives such as polyvinyl alcohol, alginates and water-soluble cellulose derivatives are preferably used. The high molecular weight material may contain additives, e.g. catalysts, fillers, parting agents, soluble dyes or insoluble pigments. The support material may be a fabric or paper, e.g. dense cotton fabric. In a modification the support is coated with a surface, e.g. silicone rubber to which the soluble adhesive will not permanently adhere and the support is removed from the dried flocked layer before or after treatment of the dried flock layer with the high molecular weight plastics material. More than one coating of the plastics material may be applied and more flocking material may be applied to the film between coats. The film may be subjected to calendering as an after-treatment. Surface changes can also be brought about with hot water. Other aftertreatment steps include embossing and printing. The films are permeable to air and water vapour but are waterproof. The films produced can be applied to a backing material such as polyurethane foam plastics, cotton, rayon, woven or knitted fabrics and synthetics in a subsequent operation. In certain cases the undried coating of plastics material may be applied to the backing material.