Patent GB-586198-A (GB)
Title: Production of modified cellulosic materials and articles having improved chemical and physical properties
IPC: C08L31/04
Filed: 1944-07-10
Abstract: A cellulosic material in any form, e.g. films, fabrics, yarns, straw, wood flour, wood veneers and paper, is reacted with a resin composition comprising one or more polyvinyl resins containing carboxyl and alcoholic hydroxyl groups, in molecular ratio of from 4 : 1 to 1.5 : 1, and preferably between 2.5 : 1 and 1.5 : 1.  The resin may be dissolved in a mixture of water and low molecular weight water-miscible solvent such as a lower aliphatic alcohol, applied to the cellulose, dried, and heated to a temperature of at least 100 DEG C., preferably between 120 DEG  and 200 DEG  C., with or without pressure.  The preferred resin compositions consist of mixtures of hydrolysed styrenemaleic anhydride interpolymers and partially hydrolysed polyvinyl acetate; more generally, the resin compositions may comprise a hydrolysed interpolymer of an a b -ethyleneically unsaturated hydrocarbon containing a single terminal methylene group, and a vinyl ester.  A number of such resins are referred to. Particularly in the coating of cellulosic material, such as wood veneers for the production of plywood, a solvent having an evaporation rate less than that of water is added, e.g. diacetone alcohol, octyl alcohol, amyl acetate, "Cellosolve" (Registered Trade Mark), butyl "Cellosolve," ethylene glycol monoethyl ether, butyl propionate, ethylene glycol monobutyl ether, ethyl lactate and butyl lactate.  Catalysts for the reaction between the cellulose and the resin may also be added, e.g. maleic acid, oxalic acid, ammonium chloride and ammonium sulphate.  The following examples are given: (1) A mixture of a solution of an interpolymer of ethylene and maleic anhydride in ethanol, a 50 per cent hydrolysed polyvinyl acetate and water is refluxed, mixed with pulverized regenerated viscose yarn and dried.  The product may be moulded and cured at 135 DEG  C. (2) Plywood is made from birch veneer coated with a solution of a hydrolysed interpolymer of styrene, maleic anhydride and vinyl acetate in ethanol.  (3) Plywood is made from birch veneer coated with a solution containing an interpolymer of styrene and maleic anhydride and hydrolysed polyvinyl acetate.  (4) Moulding powder is prepared from a mixture containing pulverized viscose yarn and the solution of resin used in (3).  (5) Moulding powder is prepared from wood flour and the solution of resin used in (2). (6) and (7) Sulphite paper is coated with a diluted solution of the resin used in (3), dried and calendered.  (8) A film is made by casting the resin solution used in (3) on to a glass plate, and is applied to the external surface of a plywood.  (9) Plywood is made with the use of a solution containing an interpolymer of styrene and maleic anhydride and hydrolysed polyvinyl acetate. (10) Moulding powder is made from wood flour and a resin solution containing an interpolymer of styrene and maleic anhydride and hydrolysed polyvinyl acetate.  (11) Plywood is made from birch veneer and a solution of a resin containing an interpolymer of indene and maleic anhydride and a hydrolysed interpolymer of ethylene and vinyl acetate.  (12) Plywood is made from birch veneer and a solution of a resin containing polymethacrylic acid and hydrolysed polyvinyl acetate.  (13) Regenerated cellulose sheets are laminated by means of a solution of a resin containing an interpolymer of styrene and maleic anhydride and hydrolysed polyvinyl acetate.  (14) and (15) Plywood is made from birch veneer and a solution containing styrenemaleic anhydride interpolymer, hydrolysed polyvinyl acetate and diacetone alcohol. Specification 562,092 is referred to.