Patent GB-1200106-A (GB)
Title: Improvements in or relating to absorbent medical, surgical and sanitary articles
Inventor: HARPER BILLY GENE
IPC: A61L15/60
Filed: 1967-05-26
Abstract: 1,200,106. Wearing apparel.DOW CHEMICAL CO. 26 May, 1967 [31 May, 1966], No. 24730/67. Heading A3V. [Also in Divisions A5, B5, C3, D1 and D2] An absorbent medical, surgical or sanitary article, for example a disposable hat band, a pad for the absorption of underarm perspiration, a breast pad for the absorption of milk or a baby diaper, comprises an insoluble water-swellable physiologically - unobjectionable cross - linked polymer held by a flexible support capable of conforming to a surface of an animal body, the polymer having been provided with a desired and required degree of cross-linking either (a) by a difunctional monomeric cross-linking agent, the polymer having been prepared by the polymerisation of a monomer mixture containing difunctional monomeric cross - linking agent in an amount of from 0.05 to 1.5 per cent by weight based on the total weight of polymerisable monomers in the monomer mixture, or (b) by irradiation, either wholly or in part, or by a chemical crosslinking agent other than a difunctional monomeric cross-linking agent, the crosslinked polymer having a degree of crosslinking equivalent to the degree of crosslinking in a polymer obtained by the polymerisation of a monomer mixture of which the polymerisable monomers consist of from 99.95 to 98.5 per cent by weight of N-vinyl pyrrolidone and correspondingly from 0.05 to 1.5 per cent by weight of the divinyl ether of ethylene glycol. The polymer may be poly-N-vinylpyrrolidone, a copolymer of acrylamide and acrylic acid, or a polyglycol polymer; other monomers from which suitable polymers may be prepared include the alkali metal salts (for example the sodium salts) of sulphonated vinyl toluene and of sulphonated styrene, sodiosulphoethylacrylate #-hydroxyethylacrylate and vinylmethyloxazolidones for example 3-vinyl-5-methyloxazolidone. Specified cross-linking agents are N, N<SP>1</SP>-methylenebisacrylamide, the divinyl ether of ethylene glycol, divinyl benzene and toluene diisocyanate. The polymer, which may be in the form of elongated fibres, a particulate solid or a sheet, may be dispersed on the flexible support which may be fibrous cloth fabric (for example woven or knitted), paper (for example wet-strength and/or creped), synthetic foam resin, felted fibre, a waterimpermeable sheet of a resinous waterinsoluble polymer (for example polyethylene, polyvinyl chloride or reconstituted cellulose) or the combination of a waterimpermeable sheet of a resineous waterinsoluble polymer and a permeable support layer of for example fabric; alternatively, the polymer may be dispersed in flexible support material, for example paper in which case the absorbent article may have been fabricated from a mixture of polymer and paper pulp. Example 15 relates to a baby diaper in which crosslinked polymer in finely subdivided form is enclosed between two support layers of wet-strength, optionally creped, paper or of thin plain nylon broadcloth, the layers being sewn together by quilting and hemmed at the edge, the polymer being a terpolymer of acrylamide, sodium acrylate and N, N<SP>1</SP>-methylenebisacrylamide. Example 16 relates to a baby diaper which consists of a backing support sheet of polyethylene adhered by cement to a sheet of polyurethane foam loaded with an equal weight of cross-linked polymer which is a terpolymer of acrylamide, potassium acrylate and N, N<SP>1</SP>-methylenebisacrylamide. Example 17 relates to a baby diaper which consists of a conventional waterproof outer covering in combination with a non-woven fabric produced by felting equal weights of synthetic cellulose ester fibres and of extruded fibres of crosslinked polymer which is a terpolymer of acrylamide, potassium acrylate and N, N<SP>1</SP>- methylenebisacrylamide. Reference also is made to a baby diaper which comprises a layer of wet-strength paper having dispersed therein particles of cross-linked polymer, which layer optionally may be laminated with external layers of paper which does not contain cross-linked polymer.