专利名称：Production of moistureproof regenerated cellulo films
chris crocker
refer to发明人：BERRY WILLIAM,OSWIN CHARLES ROBERT 申请号：US24188451
申请日：19510814
sasha blonde
公开号：US2709146Alsp 什么意思>bec成绩查询
公开日：
19550524
nth>他们的英语专利内容由知识产权出版社提供
hedy lamarr
摘要：700,619. Moistureproof regenerated cellulo films. BRITISH CELLOPHANE, Ltd. Sept. 14, 1951 [Sept. 18, 1950], No. 22893/50. Class 140 Moistureproof regenerated cellulo film with a moistureproof coating on one side only is produced by bringing a pair of purified gel regenerated cellulo films into intimate contact, drying the pair of films in continuous intimate contact to form two optically adhered plies of a single web, coating the dried single web on both sides with a moistureproof coating, and then parating the two plies of the coated web. The films may be produced on the same casting machine as in Specification 423,365, [Group IV], from visco of the same ageing and composition characteristics and may have the same thickness. The drying may be effected by passage under tension over heated drying rolls at, e.g. 90‹ C. Before being brought into contact the films may be treated with an aqueous dispersion of a colloidal anti-sticking agent, e.g. silica, sodium silicate, waterinsoluble amide, or soap, and on contact the films' are further treated to ensure a substantially greater amount, e.g. 1.5-3 times, of the agent on the outer film faces than is held between the inner faces. Before drying the contacted films may be treated with an aqueous solution of a regenerated cellulo softening agent, e.g. glycerine, or urea, with suspended therein, colloidal2012年网络流行语
matter, e.g. an anti-sticking agent such as silica, particles of a partial condensate of melamine and fo司库
rmaldehyde in an acidified aqueous medium, or hydrophilic particles of a partial condensate of urea and formaldehyde in a neutral aqueous medium. An aqueous dispersion of silica may be added to the aqueous liquid containing the urea-formaldehyde partial condensate, in which ca the particles of silica and condensate carry the same electric charge, e.g. positive, which is opposite to that of the film, due to the addition of a cationic surface active agent, e.g. cetyl trimethyl ammonium bromide, tetradecyl pyridinium bromide, or cetyl triethanol ammonium iodide. Before the colloidal material treatment the films may be treated together or singly with an aqueous solution of softening agent. The coating liquid may be an aqueous dispersion of a co-polymer, e.g. vinylidene chloride/acrylonitrile or /methylmethacrylate, a solution of nitrocellulo, high melting point paraffin wax, and gum dammar in an organic solvent, e.g. toluene, a mixture of cellulo ether or ester, gum or resin, wax and plasticizer, an organic solvent, e.g. methyl ethyl ketone/toluene, solution of a vinylidene chloride co-polymer, e.g. with vinyl chloride, or molten mixtures of ethyl cellulo, non-heat convertible resin (natural or modified gum or resin such as rosin, or a polyhydric alcohol-polbasic acid resin such as rosin modified glycerol maleate), plasticizer, and wax. If the film is treated before coating with a urea-formaldehyde partial condensate, the coating composition may contain an acidic substance, e.g. citric acid or sulphur dioxide, which catalys further condensation.
申请人：BRITISH CELLOPHANE LIMITED
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