Patent GB-384694-A (GB)
Title: Improvements in or relating to transparent films, for use, for example, as the surfac
Filed: 1931-07-17
Abstract: A process for improving the wearing qualities without affecting the transparency of transparent films, such as the surface layers of gramophone records, having as basic material a cellulose derivative or a mixture of a cellulose derivative with a synthetic resin, comprises incorporating a filler of diatomaceous earth in the form of a fine powder with the material in order to form a homogeneous mass. The diatomaceous earth, which should be light in colour and free from impurities, has a particle size of the order of ,010 mms. in diameter.  Any of the cellulose ethers or esters may be employed together with volatile solvents, such as acetone, and plastifiers, such as camphor or camphor substitutes. The manufacture of the materials when the base comprises a cellulose composition may be effected by masticating, mixing or kneading with volatile substances to form a dope or varnish or a material of putty-like consistency. Alternatively, the materials may be worked together and either pressed into blocks for subsequent slicing into sheets or passed between rolls to form a thin sheet.  A suitable cellulose composition comprises 40 parts of cellulose acetate, 30 parts of diatomaceous earth, 4\ba1/2\be parts of triphenyl phosphate, 12 parts of diethyl phthalate, and 13\ba1/2\be parts of toluene sulphonethylamide.ALSO:A process for improving the wearing qualities without affecting the transparency of transparent films, such as the surface layers of gramophone records, having as basic material a cellulose derivative or synthetic resin or a mixture of both such substances, comprises incorporating a filler of diatomaceous earth in the form of a fine powder with the material in order to form a homogeneous mass.  The diatomaceous earth, which should be light in colour and free from impurities, has a particle size of the order of ,010 mm. in diameter. Any of the cellulose ethers or esters may be employed together with volatile solvents, such as acetone, and plastifiers, such as camphor or camphor substitutes.  The manufacture of the materials when the base comprises a cellulose composition may be effected by masticating, mixing or kneading with volatile substances to form a dope or varnish or a material of putty-like consistency.  A suitable cellulose composition comprises 40 parts of cellulose acetate, 30 parts of diatomaceous earth, 4\ba1/2\be parts of triphenyl phosphate, 12 parts of diethyl phthalate, and 13\ba1/2\be parts of toluene sulphonethylamide.  In the case of synthetic resins, the filler is incorporated with a resin syrup which is prepared by condensing urea or thiourea, or a mixture of these substances, with formaldehyde. Alternatively, the resin may be prepared either from glycerine and phthalic anhydride or from vinyl acetate and vinyl chloride.  In these cases, oxalic acid or other organic acid may be added as hardening agent.  A suitable synthetic resin composition comprises 50 parts of urea or thiourea resin syrup, 25 parts of diethylene glycol, and 25 parts of diatomaceous earth.ALSO:A process for improving the wearing qualities without affecting the transparency of transparent films, such as the surface layers of gramophone records, having as basic material a cellulose derivative or synthetic resin or a mixture of both such substances, comprises incorporating a filler of diatomaceous earth in the form of a fine powder with the material in order to form a homogeneous mass.  The diatomaceous earth, which should be light in colour and free from impurities, has a particle size of the order of ,010 mms. in diameter.  Any of the cellulose ethers or esters may be employed together with volatile solvents, such as acetone, and plastifiers, such as camphor or camphor substitutes. The manufacture of the materials when the base comprises a cellulose composition may be effected by masticating, mixing or kneading with volatile substances to form a dope or varnish or a material of putty-like consistency.  Alternatively, the materials may be worked together and either pressed into blocks for subsequent slicing into sheets or passed between rolls to form a thin sheet.  A suitable cellulose composition comprises 40 parts of cellulose acetate, 30 parts of diatomaceous earth, 4 1/2 parts of triphenyl phosphate, 12 parts of diethyl phthalate, and 13 1/2 parts of toluene sulphonethylamide.  In the case of synthetic resins, the filler is incorporated with a resin syrup which is prepared by condensing urea or thiourea, or a mixture of these substances, with formaldehyde. Alternatively, the resin may be prepared either from glycerine and phthalic anhydride or from vinyl acetate and vinyl chloride.  In these cases, oxalic acid or other organic acid may be added as hardening agent.  A suitable synthetic resin composition comprises 50 parts of urea or thiourea resin syrup, 25 parts of diethylene glycol, and 25 parts of diatomaceous earth.