Abstract:
The invention relates to a water-dilutable coating containing polyester, polyurethane, amino resins and other usual paint additives and auxiliary agents. The polyurethane that is used is a mixture consisting of several, preferably two different polyurethane compounds (A, B) which preferably have a molecular weight of 1000 to 30000, preferably have an acid value of 5-20 mg KOH/g and can preferably be produced by reacting prepolymers containing isocyanate groups.
Abstract:
This invention describes a method of forming bisulphite adducts of aliphatic isocyanates bearing an aromatic moiety by mixing an aqueous solution of a bisulphite adduct forming agent with a solution of an isocyanate bearing an aromatic moiety in a substituted pyrrolidinone containing a catalytic amount of a substance which catalyses the bisulphite adduct forming reaction, the isocyanate being kept well dispersed so that the adduct is formed as a solution in the aqueous phase.
Abstract:
A modified acrylic urethane prepolymer composition and an unsaturated polyester resin composition to which the prepolymer has been added. The prepolymer composition includes an acrylic urethane prepolymer prepared by the reaction of diisocyanate, like MDI, with a hydroxyl-containing acrylate monomer, such as a pentaerythritol triacrylate, which prepolymer composition may contain a styrene monomer and an inhibitor, such as benzoquinone, to retard the reaction of the prepolymer and styrene monomer prior to the addition of the prepolymer composition into the polyester resin composition. The employment of the modified urethane prepolymer composition provides for the reduction in the amount of styrene monomer used in the unsaturated resin composition and also provides for improved chemical and physical properties of the cured, unsaturated resin composition, such as a reduction in glass roll-out when the resin composition is employed with fiberglass.
Abstract:
A water-dilutable coating agent, a process for preparing the same and its use are disclosed. The coating agent contains A) 40 to 95 % by weight of a film-forming, OH group-containing polyurethane resin or a mixture of such resins, available as an aqueous dispersion. The polyurethane resin or said mixture has in average a hydroxyl number from 25 to 250, a urethane group content from 2 to 20 % by weight, with respect to the solid resin, a numeric average of the molar mass (Mn) from 1 000 to 100 000 and, with respect to 100 g solid resin, a content of acid functionalities lower than 80 mEqu and/or a content of ethylene oxide units lower than 150 mEqu. When acid functionalities and ethylene oxide units are both present, the sum of acid functionalities and ethylene oxide units is comprised between 1 to 200 mEqu, and the acid functionalities are if required at least partially neutralised. The coating agent also contains B) 60 to 5 % by weight of one or several polyisocyanates with more than one free isocyanate group which are liquid at room temperature, if required by admixture of one or several organic solvents, the percentages by weight of (A) and (B) relating to the content of solid resin and adding up to 100 % by weight and C) if required one or several additional binders, usual pigments, fillers and/or lacquer-usual additives and auxiliary substances.
Abstract:
The invention concerns a process for producing multilayer enamel coatings in which (1) a base varnish in the form of an aqueous, pigmented base varnish containing a water-dilutable polyurethane resin is applied to the surface of the substrate, (2) a polymer film is formed from the varnish applied in step (1), (3) a transparent coating varnish is applied to the base coat so obtained, and (4) the base coat is stoved, together with the coating varnish. The water-dilutable polyurethane resin contains structural units of formula (I), wherein X stands for a divalent aromatic hydrocarbon residue and R?1 and R2¿ stand for an alkyl residue with 1 to 4 carbon atoms.
Abstract:
Thermally stable compositions containing a polyfunctional aliphatic hindered isocyanate compound and an oxazolidine compound are disclosed. The materials are stable under hot melt conditions at elevated temperatures and can cure in the presence of moisture to afford polymeric or crosslinked materials. Due to the presence of the hindered isocyanate, the cured materials are substantially free of isocyanurate products formed through the trimerization reaction of the isocyanate compounds. The absence of trimerization products produce significantly improved hot melt materials particularly useful as adhesives and sealants. The cooperation between the hindered isocyanate compound and the oxazolidine agent result in a significant improvement in stability and performance.
Abstract:
In accordance with the present invention, a blocked isocyanate composition which is useful as a curing agent for powder coatings is prepared from the reaction of tetramethylxylene diisocyanate and acetone oxime. In a preferred embodiment, a polyol is reacted with the isocyanate to provide a prepolymer with urethane linkages wherein the isocyanate groups of the prepolymer are substantially blocked with acetone oxime. The blocked isocyanate composition of the present invention can be used as a curing agent for powder coatings, adhesives and high solid coatings which are cured by baking. The blocked isocyanate composition of the invention can be used as a cross-linking agent for a hydroxy-containing polyester, a hydroxy-containing acrylic or methacrylic polymer or any other active hydrogen containing polymer.
Abstract:
The invention relates to a coating composition comprising a polyurethane ABC having tertiary amine groups, and an epoxide-functional compound D, to a process for the preparation of an aqueous dispersion of a polyurethane ABC comprising a first step wherein a polyurethane prepolymer is made from diols or polyols A, multifunctional isocyanates B, and at least one tertiary amine C bearing a tertiary amino group and at least one isocyanate-reactive group selected from the group consisting of hydroxyl groups, amino groups, hydrazine groups, hydrazide groups, and mercaptane groups, a second step comprising reacting the prepolymer with a chain stopper which is monofunctional with regard to reaction thereof with isocyanates, or a chain extender which has two or more reactive groups that react with isocyanate, a third step comprising neutralising the product of the second step with an acid, and a fourth step comprising dispersing the neutralised product of the third step in water, and to a method of use of these coating compositions comprising mixing the polyurethane ABC and the epoxide functional compound D, and applying the coating compositions to substrates selected from the group consisting of metals, coated metals, plastics, glass, concrete, wood, cardboard, and leather.
Abstract:
The invention relates to aqueous polyurethane-vinyl polymer hybrid dispersions comprising, as building blocks, hydrophobically modified hydroxy-functional polyesters A, acids B that have further groups which react with isocyanates under formation of urethanes, ureas, or thiourethanes, compounds G having only one hydroxyl group, and one or more tertiary amino groups, olefinically unsaturated monomers H2 having a polymerisable ethylenic unsaturation and a further functional group which reacts with an isocyanate group under bond formation, olefinically unsaturated monomers H1 having at least one polymerisable ethylenic unsaturation and no further functional group which reacts with an isocyanate group, and multifunctional isocyanates I having at least two isocyanate groups per molecule, to a process of their preparation, and to a method of use thereof.