GB569738A - Improvements relating to sheet materials - Google Patents

Abstract

569,738. Paper containing synthetic filaments. BRITISH CELANESE, Ltd. July 19, 1943, No. 11740. Convention date, Aug. 7, 1942. [Class 96] Filaments of cellulose acetate, propionate butyrate, acetate-propionate or acetate-butyrate, &c., of low acidyl value, i.e. containing not more than 1.8 acidyl groups per glucoside residue, are dispersed with fibres of sulphate, sulphite, soda or mechanical wood pulp, cotton, linen, hair, leather, asbestos, mineral wool, or spun glass, and formed into paper, wall board, or laminated board in which the cellulose ester filaments are bonded to the fibres as by hot calendering when the material contains about 15 per cent. of water. The products may be used for electrical insulation, gear wheels, cams, &c., or for security paper. The filaments may constitute 1 to 50 per cent. or more of the product, and they may be used with pigments, lakes, dyes, fillers, or fire retardants, e.g. with titanium, zinc, lead, or iron oxide, and may be bonded in the sheet material by the heat and pressure, without the use of solvents or plasticizers. Esterification may be effected using acetic or other acid anhydride, with sulphuric acid as a catalyst, and acetic acid as a diluent. The ester may be ripened or hydrolysed as described in Specification 568,047, [Group IV], the filaments may be wet or dry spun and may be fed as a lap or as a suspension to the paper pulp before or after beating or Jordaning.