摘要:
The invention relates to isocyanate adducts which can be prepared by reacting at least one polyisocyanate with compounds having at least two hydrogen atoms which are reactive toward isocyanate groups and have a crystalline content of less than 10 J/g determined by differential scanning calorimetry in accordance with DIN 51 004 at 20 K/min from room temperature to 250° C. using a nitrogen flow of 3 l/h as carrier gas and an aromatics content reported as carbon atoms in aromatic rings of less than 31% by weight, based on the total weight of the isocyanate adducts.
摘要翻译:本发明涉及异氰酸酯加合物,其可以通过使至少一种多异氰酸酯与具有至少两个对异氰酸酯基反应的氢原子的化合物与通过差示扫描量热法测定的结晶含量小于10J / g的化合物反应来制备, DIN 51 004以20K /分钟从室温至250℃,使用3升/小时的氮气流作为载气,芳族环中报道的芳族化合物含量小于31重量%,基于 异氰酸酯加合物的总重量。
摘要:
Polyesterols having reduced reactivity are prepared by catalytic polycondensation of dicarboxylic acids/dicarboxylic acid derivatives and H-functional substances using tin catalysts by a process wherein the polyesterols are brought into contact with oxygen after the end of the esterification reaction.The polyesterols themselves obtained by this process are used for the preparation of PU.
摘要:
A microcellular PU elastomer having improved dynamic-mechanical properties and based on an isocyanate component consisting essentially of 4,4'-MDI and also further customary constituents has, after heating at from 100 to 120.degree. C. for from 8 to 24 hours, a melting range of from 130.degree. C. as the minimum lower limit to 230.degree. C. as a minimum upper limit, measured by differential scanning calorimetry (DSC) at a heating rate of 20.degree. C./min, and a urea content of from 14 to 18% by weight.A process is also provided for preparing such a microcellular PU elastomer having improved dynamic mechanical properties. The microcellular PU elastomers can be used for producing damping elements.
摘要:
In a process for producing rigid foams based on isocyanate, the blowing agent used is a mixture of at least one low-boiling hydrocarbon having from 3 to 7 carbon atoms, low molecular weight monohydric alcohols containing primary or secondary hydroxyl groups and having from 1 to 4 carbon atoms, and, if desired, the carbon dioxide formed from water and isocyanate. The rigid foams can be used as insulation material.
摘要:
The invention relates to high-functionality polyether polyols of the general formula where each R′1 is an unsubstituted or substituted aliphatic or aromatic radical and each R′2 is an unsubstituted or substituted aliphatic or aromatic radical, H, OH, polyalkyl ether chain or halogen, each X is a polyalkyl ether chain or H, where at least one X is a polyalkyl ether chain, and m is an integer from 0 to 20, where Xm is H when m is 0, and n is an integer from 4 to 12, to processes for preparing such high-functionality polyether polyols and also to the use thereof for preparing polyurethanes and nonionic surfactants.
摘要:
Polyesterols having reduced reactivity are prepared by catalytic polycondensation of dicarboxylic acids/dicarboxylic acid derivatives and H-functional substances using tin catalysts by a process wherein the polyesterols are brought into contact with oxygen after the end of the esterification reaction. The polyesterols themselves obtained by this process are used for the preparation of PU.
摘要:
Prepolymers which contain isocyanate groups, have an NCO content of at least 30.0% by weight and can be prepared by reacting an isocyanate mixture consisting predominantly of diphenylmethane diisocyanates and polyphenylpolymethylene polyisocyanates and having a proportion of two-ring isomers of not more than 74% by weight with at least 4-functional polyols or a mixture of polyols having a mean functionality of at least 4, where the polyols or polyol mixtures have a hydroxyl number of from 200 to 1650 mg KOH/g and a number average molecular weight of less than 1100 g/mol. The present invention also provides a process for preparing these prepolymers containing isocyanate groups, provides for their use for producing polyurethanes and provides a process for producing polyurethanes by reacting at least one novel prepolymer containing isocyanate groups, if desired in admixture with further organic and/or modified organic isocyanates (a), with compounds having at least two reactive hydrogen atoms (b) in the presence of, if desired, blowing agents (c), catalysts (d) and, if desired, further auxiliaries and/or additives (e).
摘要:
A microcellular PU elastomer having improved dynamic mechanical properties and based on an isocyanate component consisting essentially of 4,4'-MDI and further customary constituents has a physicochemical structure which, in the gel permeation chromatograph (GPC) of a solution of the microcellular polyurethane elastomer prepared at 90.degree. C. in N,N-dimethylformamide containing 1 percent of di-n-butylamine measured against polymethyl methacrylate (PMMA) as standard, displays a signal occurring in addition to low molecular weight main signal and comprising one or more peaks at an (apparent) molar mass of greater than 250,000 g/mol which becomes smaller or disappears on addition of lithium chloride to this solution, and a urea content of from 14 to 18% by weight.A process is also provided for preparing such a microcellular PU elastomer having improved dynamic mechanical properties. The microcellular PU elastomers can be used for producing damping elements.
摘要:
Diisocyanates of the formula (I) where R1 is a C1-C10-hydrocarbon radical and R3 is a C1-Cl2-hydrocarbon group and n is an integer from 1 to 10, are described.