摘要:
The instant invention is directed to a process for the preparation of dihydroxypolyurethanes containing carboxyl groups and chemically fixed ionic groups, comprising reacting(A) dihydroxypolyesters having molecular weights of from 600 to 8,000;(B) organic diisocyanates;(C) compounds containing carboxyl groups and groups having a higher isocyanate-reactivity than said carboxyl groups; and(D) compounds containing ionic groups and isocyanate-reactive groupswherein the products of said process contain from 0.01 to 1.0%, by weight of carboxyl groups and from 0.1 to 10 milliequivalents of ionic groups per 100 g of polyurethane.
摘要:
This invention relates to new, substantially linear polyester polyurethanes containing hydroxyl end groups, based on selected starting materials, and their use as adhesives or for the production of adhesives.
摘要:
An adhesive consisting substantially of an aqueous solution or dispersion of a polyurethane containing chemically incorporated carboxylate and/or sulphonate groups is prepared from a mixture of at least two (cyclo)-aliphatic diisocyanate and selected polyester diols based on (i) adipic acid and (ii) tetramethylenediol, hexamethylenediol or mixtures of these diols. The use of such aqueous solutions for the formation of bonds on any substrates, in particular on leather, plastics, rubber materials and/or polyvinyl chloride containing plasticizer, with the same material or with other materials is disclosed.
摘要:
The invention relates to moisture-curable adhesive or sealant compositions comprising a) prepolymers based on aliphatic polyisocyanates and having isocyanate contents of 2 to 20 wt. %, and b) bis(dimethylaminoethyl)ether as catalyst. The compositions exhibit good storability, processability can be adjusted within wide limits and also provide rapid through-hardening.
摘要:
The present invention relates to a process for bonding two or more wood substrates by using as the adhesive isocyanate-terminated prepolymers having an isocyanate content of 8 to 20 wt. % and containing the reaction product of a) at least one organic polyisocyanate with b) at least one organic polyhydroxyl compound containing the reaction products of i) organic polyisocyanates with ii) polyamines, hydrazines and/or hydrazides having primary and/or secondary amino groups dispersed in a iii) polyethers having at least two hydroxyl groups and a number average molecular weight of 500 to 12,000; and, the present invention also relates to the bonded substrates obtained by this process.
摘要:
A process for the decomposition of polyurethane plastic waste materials in which a compound containing at least two isocyanate-reactive hydrogen atoms (e.g., glycol) and polyurethane plastic, together with 2 to 20 times the amount of previously regenerated material, are treated in a mixing and comminution device.
摘要:
The present invention is directed to a polyurethane system containing isocyanate groups prepared by reactingA) 70 to 98 parts by weight of at least one polyester diol having a melting point of 30.degree. C. to 60.degree. C. and a molecular weight of 800 to 8,000,B) 2 to 30 parts by weight of at least one polyester diol having a melting point of 65.degree. C. to 150.degree. C. and a molecular weight of 600 to 8,000, andC) no more than 1 mole of a diol having a molecular weight of less than 600 per moles of A) plus B), with,D) at least one organic polyisocyanate, the ratio of isocyanate groups to hydroxyl groups is between 3:1 and 1.2:1.
摘要:
The present invention relates to a magnetic storage medium consisting of a non-magnetic layer support and, applied thereto, a binder-containing magnetic layer, the binder consisting of from 25 to 100% of a thermoplastic polyurethane substantially free from reactive terminal groups obtained by reacting a linear polyester of at least one dicarboxylic acid containing from 2 to 8 carbon atoms and/or hydroxy carboxylic acid containing from 4 to 6 carbon atoms and at least one glycol containing from 2 to 6 carbon atoms, the polyester having a molecular weight of from 1200 to 6000, at least one diisocyanate and a mixture of at least two glycols containing from 2 to 20 carbon atoms, the molar fraction of the individual components not exceeding 0.8. The polyurethane has a hardness of from 80 to 100 Shore A, a tensile strength of from 30 to 75 MPa and a breaking elongation of from 320 to 520%.
摘要:
Polyurethane elastomers are prepared by reacting organic polyisocyanates with organic polyhydroxyl compounds and a mono-functional secondary hydroxyl group containing chain terminator. The chain terminator can be added to the polyhydroxyl compound prior to the reaction with the polyisocyanate.
摘要:
The invention relates to a composition based on alkoxysilane-functional polyurethane prepolymers suitable for a reactive hot-melt adhesive which is stable to storage at a high temperature but cures very rapidly under the action of moisture from the atmosphere or from the materials glued to one another and which is suitable for joining the most diverse materials. The invention also relates to the process for gluing the most diverse substrates using the reactive hot-melt adhesive according to the invention.