GB411860A - Improvements in or relating to the manufacture of hollow flexible articles - Google Patents

Abstract

Highly flexible articles such as tubes, finger stalls, ampull , teats and bulbs are prepared from solid elastic and flexible compositions comprising one or more wholly or partially polymerized acrylic and/or methacrylic acid esters and/or nitriles or their halogen substitution products such as the methyl, ethyl, propyl, amyl, phenyl and benzyl esters and chloracrylic acid methyl estes. In addition other substances containing the group <FORM:0411860/IV/1> may be incorporated in the manufacture such as vinyl esters, ethers and halides and their substitution products for example vinyl acetate, propionate, chloracetate, benzoate, vinyl chloride, chlorstyrol, methyl styrol, methyl-, ethyl-, butyl- and chlorethyl-vinyl ethers or vinyl methyl ketone. The polymerization products should advantageously contain a quantity, preferably at least 20 per cent, of acrylic acid nitrile, such mixed polymers being desirably heated for some time to above 100 DEG C., e.g. to 150--200 DEG C., if desired under increased pressure. Additional substances may be used to modify the properties, e.g., the products may be softened by the addition of soft polymerization products or of other softening agents, e.g., phthalic, tartaric, adipic, stearic and phosphoric esters, esters p and ethers of polyvalent alcohols such as diethylene glycol ethyl ether or acetin, or they may be strengthened by the addition of cellulose esters or ethers, e.g., nitro or acetyl cellulose, methyl, ethyl or benzyl cellulose. Other additions specified are: mineral and vegetable oils, e.g., linseed oil or castor oil; artificial or natural resins, e.g., copals or colophony, urea- and phenolformaldehyde condensation products, p-toluenesulphonamide resins, and resins from polyvalent acids and alcohols; artificial and natural caoutchouc in small quantities; basic substances such as urea, guanidine and their derivatives; filling materials e.g., talcum or kaolin; colouring matters, e.g., those of the anthraquinone series; and antiseptic agents. Also other organic or inorganic substances such as zinc stearate, lamp-black, fats or waxes may be added before, during or after polymerization, with or without solvents. The polymerization may be effected at any suitable stage in the manufacture, before or after the articles are formed or gradually or in stages during the forming of the articles, and may be carried out by the usual methods such as by the aid of heat, light and/or catalysts, in the presence or absence of solvents or diluents, e.g., water, aromatic and aliphatic hydrocarbons, e.g., benzene or benzine, chlorinated hydrocarbons, e.g., ethylene chloride, trichlorethylene, chloroform, chlorbenzene or dichlorbenzene, esters, e.g., methyl, ethyl, butyl or cyclohexyl acetate, ethers, e.g., ethyl ether or dioxane, alcohols, e.g., methanol, butanol or benzyl alcohol, or ketones, e.g., acetone, methyl ethyl ketone, cyclohexanone or methylcyclohexanone, or in emulsion, especially in aqueous dispersions. The formation of the articles may be effected by dipping, squirting, drawing or moulding, these processes being described in detail. A reinforced edge may be formed by rolling back the film to the desired thickness while it is still sticky, and, if desired, painting on a small quantity of adhesive, preferably a dilute solution of a polymerization product. Reinforcing rings, e.g., of rubber or the material known under the Registered Trade Mark "Plexigum", may be rolled into the edge. In examples: (1) a metal or porcelain tube with a hemispherical end is dipped in a solution of polymerized methyl acrylate in ethyl acetate, slowly withdrawn, suspended in water and the film is then drawn off and powdered with rice flour; (2) a form member of hard caoutchouc is dipped in a solution of polymerized ethyl acrylate, methyl glycol phthalate and camphor in benzene, slowly withdrawn and dried and the film is sprinkled with potato flour and rolled up; (3) a solution of polymerized methyl acrylate and nitrocellulose in ethyl acetate and butanol is mixed with castor oil and acetin and used as in (1); (4) tricresyl phosphate is added to an acetone solution of a mixed polymerization product of methyl acrylate and acrylic nitrile and a glass or metal tube is drawn through the solution, dried, dipped in a mineral oil solution in chlorbenzene and again passed through the acetone solution, the process being repeated several times and the film drawn off after soaking in water; (5) a mixture of polymerized ethyl acrylate and chlorbenzene is extruded through a ring nozzle into a warm chamber, the tube formed is divided up and the end divided by incisions into segments which are formed to a spherical curvature and joined by adhesion, preferably in a warm state; (6) a film of polymerized methyl acrylate and methyl glycol phthalate is drawn over a mandrel and held there at 40--50 DEG C., until it has adapted itself to the shape of the mandrel and retains it when removed; (7) a benzene solution of isoamyl methacrylate, adipic acid cyclohexyl ester and mineral oil is employed as in (1); (8) a mixture of an interpolymerization product of propyl acrylate and vinyl acetate with methylglycol phthalate is pressed in a teat mould at 100--120 DEG C.; (9) the product obtained by polymerizing a mixture of styrol, vinyl acetate, methyl acrylate and methyl methacrylate by means of benzoyl peroxide is dissolved with diamyl phthalate in ethylene chloride and the solution is employed as in any of the foregoing examples; (10) a solution of an interpolymerization product of isopropyl acrylate and acrylic acid in ethyl acetate and butanol is mixed with a solution of a phenol-formaldehyde condensation product in acetone, and the solution is employed as in (1) or (3); (11) a form member is dipped in a solution as in (4), then in a solution of mineral oil in cyclohexanone and finally in a solution as in (1); (12) polymerized ethyl acrylate and talcum are mixed on a roller mixing machine, and, with the aid of heat and pressure, tubes are prepared from the mixture by means of a tube squirting machine; (13) the polymerized ethyl acrylate in (12) is replaced by an interpolymerization product of methyl and butyl acrylates; (14) a mixture of ethyl acrylate and acrylic nitrile is polymerized, e.g., by means of benzoyl peroxide, if desired in the presence of one or more solvents, e.g., cyclohexanone, and the solution is worked up into tubes. Reference has been directed by the Comptroller to Specifications 358,534, 371,396, and 373,643.ALSO:Compositions for the manufacture of flexible articles contain one or more polymerization products of acrylic and/or methacrylic acid esters and/or nitriles or their halogen substitution products, e.g., the methyl, ethyl, propyl, amyl, phenyl and benzyl esters and chloracrylic acid methyl esters, with or without other substances containing the group CH2 = C <, such as vinyl esters, ethers and halides and their substitution products, e.g. vinyl acetate, propionate, chloracebate or benzoate, vinyl chloride, chlorstyrol, methylstyrol, methyl-, ethyl-, butyl- and chlorethyl-vinyl ethers or vinyl methyl ketone. The polymerization products should advantageously contain a quantity, preferably at least 20 per cent, of acrylic acid nitrile. Additional substances may be used to modify the properties, e.g. the products may be softened by the addition of soft polymerization products or of other softening agents, e.g. phthalic, tartaric, adipic, stearic and phosphoric esters, esters and ethers of polyvalent alcohols, such as diethylene glycol ethyl ether or acetin, or they may be strengthened by the addition of cellulose esters or ethers, e.g. nitro or acetyl cellulose, methyl, ethyl or benzyl cellulose. Other additions specified are: mineral and vegetable oils, e.g. linseed oil or castor oil; artificial or natural resins, e.g. copals or colophony, urea- and phenol-formaldehyde condensation products, p-toluenesulphonamide resins and resins from polyvalent acids and alcohols; artificial and natural caoutchouc in small quantities; basic substances such as urea, guanidine and their derivatives; filling materials, e.g. talcum or kaolin; colouring matters, e.g. those of the anthraquinone series; and antiseptic agents. Also other organic or inorganic substances such as zinc stearate, lamp-black, fats or waxes may be added before, during or after polymerization, with or without solvents. Reference has been directed by the Comptroller to Specifications 358,534, 371,396, and 373,643.