| 摘要 |
<p>1449898 Thermoformable composites; coating thermoplastics with UV-curable varnishes GENERAL ELECTRIC CO 28 Dec 1973 [2 Jan 1973] 59960/73 Heading B2E [Also in Division C3] A UV curable resin composition layer up to 100 mils thick is coated onto a thermoplastic substrate and cured by irradiation with U.V. radiation of 1849Š to 4000Š wavelength being free of radiation of wavelength greater than 7500A and of at least 0.2 watts/sq. in. intensity, the temperature of the substrate being maintained at 60‹C or below, and the resin composition consisting of a solventless varnish having a viscosity of at least 500 centipoises at 25‹C and containing: 0.05 to 5% by wt. of a U.V. sensitiser; an aliphatically unsaturated monomer; and an unsaturated polyester soluble in the monomer having M.W. of 2-10,000 and consisting of (a)α, #-unsaturated dicarboxylic acid units, (b) dicarboxylic acid units having between the carbonyl radicals C 5-30 divalent aromatic or alicyclic organic radicals, (c) linear saturated aliphatic dicarboxylic acid units having 1-3 C atoms between carbonyl radicals, and (d) linear saturated aliphatic dicarboxylic acid units having at least 4 carbon atoms between carbonyl radicals, wherein, based on the constituents of the unsaturated polyester, there is 0.01 to 10 mole% of (a), 0 to 99.5 mole% of (b), 0 to 70 mole% of (c) and 0 to 30% of (d), and the weight ratio of aliphatically unsaturated monomer to unsaturated polyester is 0.4:1 to 4:1. In Examples: (1) a styrene/polyester mixture is doctored onto a polystyrene sheet, the polyester being formed from isophthalic acid, fumaric acid and propylene glycol; (2) as in (1) but using transparent polycarbonate sheet substrates; (3) and (4) polystyrene sheets were coated with varnishes containing styrene, benzoin methyl ether, wax and various polyesters made from acids and glycols selected from fumaric, isophthalic, tetrahydrophthalic and adipic acids and propylene and neopentyl glycols. Suitable polyester components, cross-linking monomers and U.V. sensitisers for use in the compositions are listed. Other substrates mentioned are sheets of A.B.S. resin, P.V.C.. and polypropylene. Substrates may be biaxially stretched after coating e.g. by roll coating. Fillers, dyes or pigments may be included in the varnish and barytes, gypsum, CaCO 3 , clay, talc, asbestine, mica, bentonite, aerogels. glass fibres, basic white lead carbonate, antimony oxide, lithopone, TiO 2 , ultramarine blue and Al powder are mentioned. Paraffin wax may also be included. The radiation may be supplied by U.V. lamps having heat filters.</p> |
