摘要:
Aqueous dispersions having low VOCs are dispersions or solutions of polyesters. The polyesters useful are formed from A) between about 30 and about 60 mole percent polycarboxylic acids, of which at least about 80 mole percent comprises cyclohexanedicarboxylic acids, B) between about 35 and about 70 mole percent polyols of which at least about 95 mole percent comprises diols, and between about 40 and about 100 mole percent of the polyol content comprising cycloaliphatic diols, and C) between about 5 and about 25 mole percent of a monomer having dihydroxy, monocarboxylic acid functionality. The molar ratio of (B+C)/A is between about 1.01 and about 1.30, whereby the polyester is hydroxyl-terminated having hydroxyl numbers of between about 20 and about 150 and acid numbers between about 30 and about 100. The weight average molecular weight of the polyester is between about 1000 and about 20,000. In aqueous dispersions or solutions, the acid functionality of the polyester is neutralized with base to at least about 40%.
摘要:
A low cost, high performance coating for sheet metal which is to be formed into siding for houses and automobile panels is made from a polyester prepared by the condensation of hexahydrophthalic acid and a mixture of 1,4-cyclohexanedimethanol and an acyclic polyol wherein the mole percent of acyclic polyol is from 50 to 60; and a crosslinking agent containing the --N--CH.sub.2 --OR moiety wherein R is hydrogen or an alkyl group having from 1 to 4 carbon atoms and the unsatisfied valence is attached to an organic group capable of incorporation into a film.
摘要:
A coating composition adapted to adhere to a chrome surface is disclosed in which a solvent soluble hydroxy-functional acrylic copolymer, including a copolymerized tertiary amine monomer in an amount of from 5% to 40% of the weight of the copolymer, is combined with an organic polyisocyanate curing agent for the soluble copolymer, this composition containing the copolymer and the polyisocyanate curing agent in amounts to provide an equivalent ratio of NCO:OH of from 1.2:1 to 0.5:1. The two components are provided as a two package system which is mixed prior to application.
摘要:
A thermosetting, organic solvent-based, primer coating composition for protecting metal surfaces which includes a solvent solution of: (a) a hydroxy-functional polyester resin; (b) a thermosetting acrylic resin; (c) a hydroxy-terminal polybutadiene resin, a hydroxy-terminal epoxidized polybutadiene resin, or mixtures thereof; (d) a blocked isocyanate crosslinker including at least one dimethyl pyrazole blocked isocyanate; (e) an aminoplast crosslinker including at least one melamine-formaldehyde condensate; (f) a catalyst; and, (g) a pigment. The primer exhibits excellent flexibility after curing to allow the primer to be coil coated onto metals as a thicker film and to have the metal subsequently formed without film fracture or loss of adhesion. The primer also has improved solvent release properties during curing to allow volatiles to readily escape therefrom, which facilitates coil coating of the primer onto metals as thicker films that, when cured into thick film hardened surface finishes, do not exhibit the typical blisters, craters, pops, voids and other surface defects. The primer can be cured as well at reduced temperatures which contributes to the reduction in surface defects. A fluorocarbon topcoat is usually coil coated and cured over the non-blistering primer coating, to yield a composite coated metal substrate having a surface finish that is free of blisters, craters, pops, and voids, and other surface defects.
摘要:
A silicone/polyester adduct comprises between about 5 and about 30 wt % of silicone adducted to between about 70 and about 95% polyester chains formed from polyfunctional acids plus polyfunctional acids and/or anhydrides. At least about 50 mole percent of the polyfunctional acids and/or anhydrides are cycloaliphatic.
摘要:
An hydroxy-functional polyurethane reaction product is disclosed which enables the provision of thermosetting solution coating compositions which cure at low temperature to form flexible coatings. These polyurethanes are provided by the reaction of an organic diisocyanate with a stoichiometric excess of an essentially linear hydroxy-functional polyester which is the polyesterification reaction product of C.sub.4 -C.sub.10 aliphatic dicarboxylic acid or anhydride thereof with a stoichiometric excess of C.sub.3 -C.sub.8 aliphatic diol providing an alcohol/acid molar ratio of 3/2 to 6/5. The reaction is substantially complete as indicated by an acid number less than 10, and the diisocyanate is used in an amount providing an NCO/OH ratio of from 2/3 to 12/13. The thermosetting solution coating composition is provided by an organic solvent having dissolved therein from 5-50% of total resin solids of a curing agent reactive with hydroxy groups together with the polyurethane which has been described. The preferred curing agent is a partially methylolated melamine which contains from about 5 mol percent to about 40 mol percent of the methylol group.
摘要:
A method of providing a stone chip-resistant finish to the undersurface of an automobile is disclosed in which the undersurface is coated with a cationically initiated liquid mixture of cationically curable polyepoxide, polyhydric alcohol, and a photoinitiator for an ultraviolet-activated cationic cure. The liquid mixture is applied at a resin solids content of at least about 50% and in a thickness to provide a cured coating of at least 2 mils thick, and the wet coating is cured by exposing it to ultraviolet light. The automobile undersurface is desirably primed with a cross-linked amine-functional polymer primer, and the coating includes from 1% to 8% of a finely divided silica which prevents running but does not interfere with the ultraviolet cure.
摘要:
An ultraviolet light-curable liquid coating composition for molded plastic objects is disclosed. The composition is a liquid mixture of a polyurethane oligomer polyacrylate and an hydroxy-functional polyacrylate ester. The polyacrylate ester is present in an amount of 5% to 95% of total polyacrylate. The composition is preferably in solution in alcoholic solvent having a solids content of from 40% to 90%. A photoinitiator is included to render the composition curable upon exposure to ultraviolet light.
摘要:
A waterborne thermoset cured anticorrosion formulation includes a water dispersed or emulsified phosphonated or water dispersed or emulsified sulfonated epoxy resin that is cured with a phenoxy resin having a polyhydroxyl ether backbone and terminal alpha glycol moieties. Water is present as a predominant volatile in which the epoxy resin and phenoxy resin are present in a weight ratio of epoxy resin to phenoxy resin of between 0.1 and 3:1. An aqueous curative is provided to induce cure between the epoxy resin and phenoxy resin, A corrosion inhibiting metal salt is also present having a salt anion of phosphate, biphosphate or tetraborate and a metal cation with the proviso that the metal cation formulation as a whole is devoid of chromium, lead, cobalt, and cadmium. Ideal curatives include aqueous aminoplast crosslinkers, aqueous unblocked isocyanates, aqueous blocked isocyanates, and a mixture thereof. With the inclusion of electrically conductive aluminum or zinc particulate the formulation is rendered corrosion resistant as well as electrically conductive to make an inventive coating amenable to powder coating.
摘要:
This invention relates to a method for embedding a multiplicity of discrete masses of material in a resinous coating on a sheet of metal in a coil coating system. The sheet is coated, the masses are embedded in the wet resinous coating, and the coating is dried in a one-pass system. The resinous coating and the embedded masses are preferably resistant to ultra-violet radiation. The wet resinous coating, therefore, is preferably a liquid fluorocarbon resin. The discrete masses comprise pigmented particulate minerals and resins in the form of granules, beads, vesiculated beads, pellets, flakes, platelets, cylinders, coating powders, and coating powder precursor chips. The minerals include glass, quartz, mica, pebbles, and ceramics. The particulate resins include polyesters, acrylics, nylons, polyurethanes, polycarbonates, solid fluorocarbon resins, and solid mixtures of a fluorocarbon resin and an acrylate or methacrylate polymer or copolymer. Sheet metal decorated in such a manner is useful as stock in the manufacture of metal roofing shingles simulating the appearance of traditional asphalt shingles.