| 摘要 |
Polishes comprise solutions of resinous products obtained by condensing a partially hydrolyzed polyvinyl ester, containing a substantial proportion of unchanged acid groups, with an aldehyde, which solutions may also contain other bodies such as other synthetic resins, e.g. ester gum, polyvinyl esters, rezyls or polystyrols, natural resins, e.g. shellac, elemi or rosin, cellulose derivatives, e.g. cellulose nitrate, plasticizers, e.g. diamyl or dibutyl phthalate, diacetin or triacetin, or waxes. Specifications 378,608 and 405,986 are referred to.ALSO:Solutions of resinous products obtained by condensing a partially hydrolysed polyvinyl ester, containing a substantial proportion of unchanged acid groups, with an aldehyde, which solutions may also contain other bodies such as other synthetic resins, e.g. ester gum, polyvinyl esters, rezyls or polystyrols, natural resins, e.g. shellac, elemi or rosin, cellulose derivatives, e.g. cellulose nitrate, plasticizers, e.g. diamyl or dibutyl phthalate, diacetin or triacetin, or waxes, are employed for impregnating materials, for the production of detachable films (transparent, colourless or coloured, or opaque) and as adhesives and polishes. The impregnated material, after evaporation of the solvents, may be pressed to form moulded articles. Thus impregnated sheets of paper or fabric yield moisture- and grease-resistant products of good dielectric properties, impregnated woven or felted asbestos forms brake linings and insulating panels (the surface of which may be polished), compositions from leather fibre can be made into sheets of artificial leather which may be embossed to imitate the grain of natural leather for use in upholstery or book-binding, or heavier sheets may be used in the manufacture of luggage or other articles, whilst compositions from ground cork may be used for making stoppers, playing balls, handles or floor coverings and those from wood flour or wood pulp for making moulded articles of furniture. Other fillers specified are animal, vegetable or mineral fibre, and clay. Films may be made by applying the solutions, to which may be added dyes, or pigments, e.g. titanium oxide, zinc oxide, barytes, iron oxides or metal powders, to a rotating heated drum or other suitable device and, after evaporation of the solvent, stripping away the resulting film, or sheets of greater than film thickness may be formed and pressed, e.g. by hot rolling, to accurately gauged thickness. The films may be placed between sheets, e.g. of paper or textile fabrics, and caused to adhere thereto by application of heat or heat and pressure, and they may also be used for joining together wood, leather, rubber &c. They may also be employed as wrappings or veneers or as a foundation for subsequent coats of oil varnishes, paints or cellulose lacquers. In examples: (1) films useful for wrapping purposes are produced from solutions in toluene or toluene and methyl alcohol of resins obtained by (a) 70 per cent hydrolysis of polyvinyl acetate in the presence of acetaldehyde, or (b) 80 per cent hydrolysis of polyvinyl acetate in the presence of paraformaldehyde; the solutions may be stained or may be rendered opaque by the addition of filling material, and the films may be made more flexible by adding dibutyl phthalate; (2) a film is formed from a solution in ethyl or methyl alcohol of a resin made by 30 per cent hydrolysis of polyvinyl acetate in the presence of acetaldehyde, and may be used as a dry adhesive by placing it between two articles and applying heat or heat and pressure; (3) adhesives, applicable in wet or dry form, comprise solutions in ethyl or methyl alcohol or acetone of the resins of (1) or (2); (4) sheets of paper or fabric are impregnated with solutions of the resins of (1) or (2) and a plurality of superposed sheets are subjected, preferably after evaporation of the solvent, to pressure with or without heat, producing a composite sheet resistant to water and having electric insulating properties; instead of using preformed sheets wood pulp or other vegetable or mineral fibre may be impregnated and formed into sheets; (5) felted or woven asbestos is impregnated with a solution as in (1) and, after evaporation of the solvent, subjected to pressure to produce a brake lining; (6) ground cork is mixed with the solutions of (1) or (2) and, after evaporation of the solvent, the mixture is pressed to form bottle stoppers, playing balls, handles or coverings therefor; (7) ground cork and wood flour, with or without vegetable fibre or other fillers or colouring matter, are mixed with solutions as in (6) and the mixture is rolled into sheets on a fabric foundation to form floor coverings; (8) wood flour or wood pulp or both and suitable colouring matter are mixed with the solutions of (1) or (2) and, after evaporation of most of the solvent, the mass is moulded into articles of furniture or parts thereof; (9) leather or other suitable fibre is added to the solutions of (1) or (2) and the mixture is formed into sheets of suitable thickness which when dry may be embossed to imitate natural leather. In any of examples (4) to (9) there may be added a wax, e.g. carnauba or montan wax or wax tailings. Resins may also be employed which are produced from polyvinyl esters other than the acetate, e.g. the propionate or butyrate. Specifications 378,608 (as open to inspection under Sect. 91 of the Acts) and 405,986 are referred to.ALSO:Moulding-compositions are manufactured by impregnating fillers with solutions of resinous products obtained by condensing a partially hydrolyzed polyvinyl ester, containing a substantial proportion of unchanged acid groups, with an aldehyde, which solutions may also contain other bodies such as other synthetic resins, e.g. ester gum, polyvinyl esters, rezyls or polystyrols, natural resins, e.g. shellac, elemi or rosin, cellulose derivatives, e.g. cellulose nitrate, plasticizers, e.g. diamyl or dibutyl phthalate, diacetin or triacetin, or waxes, the solvent being allowed to evaporate. Fillers specified are: sheets of paper or fabric, woven or felted asbestos (for brake linings and insulating panels), leather fibre (for sheets of artificial leather), ground cork (for stoppers, playing balls, handles or floor coverings), wood flour or wood pulp (for moulded articles of furniture), animal, vegetable or mineral fibre and clay. In examples: (1) sheets of paper or fabric are impregnated with solutions of resins formed by: (a) 70 per cent hydrolysis of polyvinyl acetate in the presence of acetaldehyde; (b) 80 per cent hydrolysis of polyvinyl acetate in the presence of paraformaldehyde; or (c) 30 per cent hydrolysis of polyvinyl acetate in the presence of acetaldehyde; (2) felted or woven asbestos is impregnated with a solution of resin (a) or (b) in toluene or toluene and methyl alcohol, and, after evaporation of the solvent, subjected to pressure to produce a brake lining; (3) ground cork is mixed with a solution as in (2) or a solution of resin (c) in ethyl or methyl alcohol and, after evaporation of the solvent, the mixture is pressed to form bottle stoppers, playing balls, handles or coverings therefore; (4) ground cork and wood flour, with or without vegetable fibre or other fillers or colouring matter, one mixed with solutions as in (3) and the mixture is rolled into sheets on a fabric foundation to form floor coverings; (5) wood flour or wood pulp or both and suitable colouring matter are mixed with the solutions as in (3) and, after evaporation of the solvent, the mass is moulded into articles of furniture or parts thereof; (9) leather or other suitable fibre is added to the solutions as in (3) and the mixture is formed into sheets of suitable thickness which when dry may be embossed to imitate natural leather. In any of the examples there may be added a wax, e.g. carnauba or montan wax or wax tailings. Adhesives.-Two or more pieces of material, e.g. wood, leather, or rubber, are connected together by means of the resin solutions described above, or by films formed by evaporating the solutions, either separately or on the material, heat or heat and pressure being applied in the latter case. In examples: (1) a film formed from a solution of resin (c) above in ethyl or methyl alcohol is used as a dry adhesive by placing it between two articles and applying heat or heat and pressure; (2) adhesives applicable in wet or dry form comprise solutions in ethyl or methyl alcohol or acetone of resin (a), (b) or (c). Specifications 378,608 and 405,986, [both in Group III], are referred to. |
