摘要:
The present invention is directed to water soluble or dispersible blocked polyisocyanates which contain(a) a statistical average per molecule of at least one structural unit corresponding to the formula:B--CO--NH-- wherein B denotes a group obtainable by removal of the acidic hydrogen atom from a monofunctional blocking agent for organic isocyanates and(b) structural units corresponding to the formula ##STR1## in a quantity sufficient to ensure the solubility or dispersibility of the blocked polyisocyanate in water,the blocked polyisocyanates containing on statistical average a total of at least two structural units corresponding to the formulae (a) and (b) per molecule.The present invention also relates to a process for the preparation of these blocked polyisocyanates and to their use in combination with water soluble or dispersible organic compounds containing at least two isocyanate-reactive groups for the production of coated substrates which are cured by heating.
摘要:
The present invention is directed to a process for the production of water- and solvent-resistant coated substrates by coating heat-resistant substrates with a solution or dispersion of an anionic group-containing polyisocyanate addition product in an aqueous solvent or dispersant and subsequently thermally treating the coating at a temperature of about 60.degree. to 200.degree. C., with evaporation or vaporization of the solvent or dispersant and simultaneous crosslinking of the polyisocyanate addition product which has been applied to the substrate, characterized in that incorporated anionic structural units corresponding to the formula ##STR1## are used in a quantity of about 5 to 1000 milliequivalents per 100 g of solids and the solids are based on reaction products of organic polyisocyanates with salts of cyanamide and bases selected from ammonia, primary and secondary amines having a minimum pKb value of 3.1, tertiary amines and mixtures thereof. The present invention also relates to the aqueous solutions or dispersions of anionically-modified polyisocyanate addition products.
摘要:
Compounds having a melting point above 40.degree. C. which compounds contain uretone imine groups and which are substantially free from volatile isocyanate blocking agents which are split off under stoving conditions are excellent crosslinking agents for pulverulent coating compositions based on hydroxyl groups-containing polymers.
摘要:
The present invention is directed to an improved process for the direct preparation of polyurethane powders in a finely divided form by the reaction of polyisocyanates and isocyanate reactive compounds in a carrier phase, using interface active compounds, the improvement wherein the interface active compound used consists of at least one polymer of a urethane of (i) a long chain alkyl isocyanate and (ii) a hydroxyalkyl-acrylic or -metacrylic acid ester.
摘要:
Liquid crystalline bis-chlorocarbonic acid esters are 4-hydroxybenzoic acid-(4'-hydroxyphenyl) esters corresponding to the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote, independently of one another, hydrogen, a halogen atom or a C.sub.1 to C.sub.6 alkyl group. Preparation of (I) and liquid crystalline N-alkyl polyurethanes and polycarbonates prepared form (I) are other invention embodiments.
摘要:
The present invention is directed to novel surface active copolymers and the use thereof in the production of polyurethane powders. More particularly, the copolymers comprise have a substantially linear structure and are obtained by copolymerization ofA) a partial reaction product of1) (meth)acrylic acid or a derivative thereof and2) a macromolecular compound substituted by at least two functional groups selected from OH and NH.sub.2, the functional groups not reacted with Al) being irreversibly blocked, withB) a urethane of 1) a long-chain alkyl isocyanate and 2) a hydroxyalkyl (meth)acrylate.
摘要:
Liquid crystalline bis-chlorocarbonic acid esters are 4-hydroxybenzoic acid-(4'-hydroxyphenyl) esters corresponding to the following formula ##STR1## wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4 denote, independently of one another, hydrogen, a halogen atom or a C.sub.1 to C.sub.6 alkyl group. Preparation of (I) and liquid crystalline N-alkyl polyurethanes and polycarbonates prepared from (I) are other invention embodiments.
摘要:
A process is described for the preparation of polymeric networks having superstructures, resulting from the use of liquid-crystalline, (poly)functional units, characterized in that build-up into polymers is carried out by the polymerization, polyaddition or polycondensation process within the liquid-crystalline, preferably nematic, temperature range of the (poly)functional units, having a liquid-crystalline character, used for building up the networks.Polymeric networks which are accessible by this process, and the use thereof, are also claimed.
摘要:
A binder for a coating composition is a combination of(a) polymers containing intramolecular carboxylic anhydride groups and having an average molecular weight of from 500 to 25,000 and(b) organic compounds containing 4,5-dihydrooxazole groups in a quantity corresponding to an equivalent ratio of carboxylic anhydride groups to 4,5-dihydrooxazole groups of from 0.5:1 to 2:1, and contains from 0.005 to 5% by weight, based on the weight of components (a) and (b), of ammonia, a primary amine or secondary amine.
摘要:
Polyamide block copolymers obtained by activated anionic polymerization of lactams having at least 5 ring members in the presence of basic catalysts, polyisocyanates as activators and amino-terminated polyethers, which are characterized in that the amino-terminated polyethers have a functionality of at least 3.0 preferably at least 3.2, and a molecular weight of at least 3500, and the polyisocyanates are aliphatic or cycloaliphatic polyisocyanates.