摘要:
The present invention relates to the preparation of powdered heat-curable reaction mixtures in which melt suspension of (a) solid polyisocyanates having melting points above about 60.degree. C., (b) molten high molecular weight isocyanate-reactive compounds having molecular weights of from 400 to 10,000 that have melting or softening points of 50.degree. C. to 150.degree. C., and (c) optionally, solid or liquid low molecular weight chain-extending or crosslinking compounds having molecular weights of from 62 to 399, are added to an inert solvent containing an emulsifier, thereby forming powdered heat-curable reaction mixtures in which components (a), (b), and (c) remain in uncrossedlinked form. The invention further relates to the use of the heat-curing reaction mixtures for the preparation of high-quality polyurethane polyurea plastics.
摘要:
This invention relates to a process for the production of solid polyamines stabilized by a polyadduct covering and showing retarded reactivity comprising reacting(1) one or more solid organic polyamines in particulate form, said polyamines containing at least two primary and/or secondary amino groups and having melting points above 50.degree. C., and(2) from 0.1 to 25 equivalent % of isocyanate per amine equivalent of a water insoluble, difunctional and/or higher functional polyisocyanate,said reaction being conducted at a temperature below the melting point of said solid polyamine, and being conducted in the presence of(3) a liquid medium selected from the group consisting of(a) organic compounds containing two or more hydroxy groups and having molecular weights of from 62 to 10,000,(b) plasticizers,(c) water, and(d) mixtures thereofto form a suspension of polyadduct-covered stabilized polyamines in the liquid medium.
摘要:
High molecular weight amines having reduced low molecular weight amine contents are obtained by reacting a mixture of (1) a high molecular weight amine and (2) a low molecular weight amine with (3) an isocyanate in quantities such that from 0.5 to 10 equivalents of isocyanate are present for each equivalent of low molecular weight amine. The product of high molecular weight amines is particularly useful in the production of isocyanate addition products such as polyurethane plastics and foams.
摘要:
A composite plastic molding made up of a plastic foam and having a polyurethane skin is made by heating a reactive one-component system to form a polyurethane skin and then joining the polyurethane skin to the plastic foam. The one-component system is composed of a finely divided polyisocyanate in which from 0.1 to 25 equivalent percent of the isocyanate groups have been deactivated, a polyamine and/or polyol having a molecular weight of from 400 to 8000 and optionally a chain extending agent, a catalyst and known auxiliaries and additives.
摘要:
According to the present invention, relatively high molecular weight aliphatic and/or aromatic polyamines having molecular weights of from 400 to 8,000 (preferably from 600 to 4,000) are mixed with substantially equivalent quantities of low molecular weight, solid, finely-divided diisocyanates having a melting point of >40.degree. C., (preferably >80.degree. C.), such as phenylene diisocyanate, naphth lene-1,5-diisocyanate, dimeric toluylene-2,4-diisocyanate or the urea diisocyanate of toluylene-2,4-diisocyanate. This mixture, having a pot life of at least several minutes, is subsequently heated to a relatively high temperature, such as from 80.degree. to 200.degree. C.The products obtained have excellent elastic properties over a broad temperature range. They have an exceptionally flat modulus of elasticity curve (G') in the torsional vibration test. The hard and soft segments are markedly segregated and are thus not substantially disturbed by reciprocal interaction causing "softening".
摘要:
The present invention is directed to a reactive polyurethane mixture comprising:A) at least one polyisocyanate,B) a polyol mixture comprising:B1) at least one polyol containing three or more hydroxyl groups and having a molecular weight in the range from 800 to 6,000,B2) at least one polyol containing three or more hydroxyl groups and having a molecular weight in the range from 400 to 799 andB3) at least one polyol containing three or more hydroxyl groups and having a molecular weight in the range from 92 to 399, andC) at least one polyamine.
摘要:
The invention relates to a process for improving the flowability and preventing the agglomeration of finely divided dimerized 2,4-toluene diisocyanate in which a precipitated silicas and/or pyrogenic silica having a hydrophobic surface is added to the finely divided dimerized 2,4-toluene diisocyanate. The invention also relates to the finely divided dimerized 2,4-toluene diisocyanate prepared by this process.
摘要:
The present invention relates to a heat curable, one-component polyurethane reactive compositions containingA) surface-modified, finely divided polyisocyanates in which 0.1 to 25 equivalent percent, based on the total number of NCO groups, of the NCO groups are deactivated andB) a mixture of relatively high molecular weight compounds having isocyanate-reactive groups containing1) 5 to 40 wt. %, based on the weight of component B), of one or more aliphatic polyether polyamines and2) 60 to 95 wt. %, based on the weight of component B), of a polyol mixture containingi) 10 to 60 wt. %, based on the weight of component B2), of at least one polyester polyol andii) 40 to 90 wt. %, based on the weight of component B2), of at least one polyether polyol with predominantly primary hydroxyl groups.The present invention also relates to use of the heat curable, one-component polyurethane reactive compositions to prepare coatings, adhesives, anti-drumming products and sealants, especially seam sealants.
摘要:
The present invention relates to a process for the preparation of a modified 1,5-naphthylene diisocyanate containing urea and biuret groups comprising reacting(a) 1,5-naphthylene diisocyanate in molten form with(b) a mixture comprising about 0.02 to about 0.5 mole of water per mole of 1,5-naphthylene diisocyanate and about 1 to about 10 parts for each part of water of an organic solvent.The present invention further relates to a process for the preparation of elastomeric moldings comprising reacting by the one-shot or prepolymer process at an isocyanate index of 70 to 130 a modified 1,5-naphthylene diisocyanate containing urea and biuret groups with compounds containing at least two isocyanate-reactive groups and having a molecular weight in the range from about 500 to about 10,000 and, optionally, organic compounds containing isocyanate-reactive groups and having a molecular weight in the range from 60 to 499.
摘要:
The present invention relates to heat-curable reaction systems prepared by mixing (a) solid polyisocyanates (optionally deactivated) having melting points above 80.degree. C., (b) OH- and/or NH.sub.2 -terminated polyoxyalkylene polyethers that have molecular weights of 400 to 10,000 and are liquid at room temperature, (c) solid OH- and/or NH.sub.2 -terminated polyesters that have molecular weights of 400 to 20,000 and are solid at room temperature, and which are thoroughly distributed throughout the mixture but are not homogeneously miscible with the polyether, (d) optional low molecular weight chain-extending agents that contain OH and/or NH.sub.2 groups and have a molecular weight of 62 to 399, and (e) optional catalysts and other auxiliaries. The invention further relates to a method for preparing elastomers, coating compounds, sealing compounds, or adhesives by heat-curing the heat-curable systems.