Patent GB-635345-A (GB)
Title: Process for transfer coating and transfer sheets for use therein
IPC: D06P5/24
Filed: 1946-05-17
Abstract: 635,345. Coated fabrics. SYLVANIA INDUSTRIAL CORPORATION. May 17, 1946, No. 14936. Convention date, May 18, 1945. [Class 140] [Also in Group XVI] A transfer sheet which is especially applicable for transferring a coated layer to fabrics or to rough surfaces such as leather for forming waterproof or like surfaces is formed of a backing sheet, which is soft and resilient, and a transfer film which may be formed of similar materials to the backing sheet but is chosen so as to have a thermal tacking point lower than the thermal softening point of the backing sheet so that the film can be transferred by heat and pressure. The transfer film may be applied to the backing sheet by dissolving it in a solvent which does not dissolve the backing sheet, or by application in a molten state. The backing sheet may be made of thermoplastic resins such as polyvinyl chloride, polyvinylidene chloride, polystrene, copolymers of vinyl chloride and acetate, and of methylmethacrylate and vinyl chloride, polyvinyl butyral or acetal, polymethyl methacrylate or acrylate, polyethylene, polyamides, oil-modified and unmodified alkyd resins prepared from dihydroxy alcohols and dicarboxylic acids, phenol-formaldehyde resins and natural rubbers and synthetic rubbers such as chlorinated rubber, polysulphides, polyisobutylenes, polychloroprene, cyclized rubber, Buna rubber, and rubber hydrochloride, cumarone-indene with rubber. The backing sheet may also be a thermo-setting resin such as urea-formaldehyde, phenol-formaldehyde, melamine-formaldehyde, alkyd resins, phenol-furfural, unsaturated polyesters, polyalkyl alcohol, proteinformaldehyde resins, casein formaldehyde, shellac-formaldehyde ; or mixtures of resins such as polyvinyl chloride and ureaformaldehyde - butanol ether, polyvinyl chloride and phenol - formaldehyde, polymethyl methacrylate and urea-formaldehyde, polystyrene and an alkyd resin, cumaroneindene and an alkyd resin, polyvinyl acetal and melamine-formaldehyde. The transfer film may be any relatively highly plasticized thermoplastic hydrophobic film-forming material selected from the above list, and thermoplastic and thermosetting resins may be used in mixture, and when thermosetting resins are used they may be cured after transfer. As an example applied to the formation of a nylon cloth rendered impervious to moisture and gases, a backing sheet formed of polyvinyledene chloride is coated with an acetone solution containing 12. per cent cellulose nitrate, and 1 per cent dibutyl phthalate, and pigments added to give an olive colour. After evaporation of the solvent the dried film is heated to render it tacky and it is then applied to nylon cloth, and after cooling the backing sheet is removed. Other examples are quoted in Group XVI. Specification 635,344 is referred to. The Specification as open to inspection under Sect. 91, also comprises the use of backing sheets made of thermoplastic cellulose derivatives such as cellulose acetate, cellulose acetate butyrate or propionate, cellulose propionate, benzyl cellulose, ethyl cellulose, butyl cellulose, hydroxy ethyl cellulose. This subject-matter does not appear in the Specification as accepted.