摘要:
Rigid polyurethane foams are prepared by the reaction of1) polyisocyanates with2) compounds of a molecular weight of from 150 to 1500, having at least two hydrogen atoms active towards isocyanates and which one tertiary nitrogen atom in the molecule, in the presence of3) hydrofluoroalkanes as foaming agents as well as optionally in the presence of4) other auxiliary substances and additives known per se.
摘要:
A process for insulating pipes comprises applying at least one layer of a polyisocyanurate plastic and then at least one layer of rigid polyurethane foam to a steel pipe. The foam is covered with an outer layer.
摘要:
The invention relates to antistatic and electrically conductive polyurethanes containing conductive carbon blacks and carbon fibers, and the use thereof.
摘要:
The invention provides a process for the production of flexible to semi-rigid polyurethane shaped articles with a compacted edge zone of given hardness and a significantly more flexible cell core, so-called integral foams, in which non-combustible mixtures of fluoroalkanes which comprise 1,1,1,3,3-pentafluorobutane (R 365mfc) are employed as physical blowing agents.
摘要:
The invention relates to a process for insulating pipes by applying a rigid polyurethane foam as an insulating layer and optionally an external top coating by the rotational casting process. The rigid polyurethane foam is obtained by a) an aromatic polyisocyanate, b) an organic polyhydroxyl compound, c) an aliphatic, cycloaliphatic or aromatic polyamine and/or polyimine having a molecular weight of from 32 to 1,000 as the cross linking agent in the presence d) a blowing agent, and optionally in the presence of e) known auxiliary substances and additives and in the presence of f) one or more compounds having a molecular weight of from about 166 to about 1,000 and being of the general formula ##STR1## wherein n represents an integer between 2 and 9, preferably 2 and 3,R.sup.1 signifies hydrogen, a C.sub.1 -C.sub.9 alkyl radical or a ##STR2## R.sup.2 signifies hydrogen, and R.sup.3 and R.sup.4 signify hydrogen or methyl.
摘要:
The present invention relates to hard polyurethane foams. These foams are produced by the reaction of 1) polyisocyanates, with 2) compounds having molecular weights of from 92 to 10,000 and having at least two hydrogen atoms which are reactive with isocyanate groups, in the presence of 3) hydrofluoroalkanes as foaming agents, and 4) solubilizers. Suitable solubilizers comprise one or more of ##STR1## wherein R.sup.1 and R.sup.2 signify C.sub.1 -C.sub.12 -alkyl or together C.sub.2 -C.sub.6 -alkylene and n signifies an integer from 0 to 6; ##STR2## wherein R.sup.1 to R.sup.3 signify C.sub.1 -C.sub.12 -alkyl which is optionally substituted by halogens, C.sub.5 -C.sub.10 -cycloalkyl or optionally substituted aryl; ##STR3## wherein R.sup.1 and R.sup.2 signify C.sub.1 -C.sub.16 -alkyl or C.sub.5 -C.sub.10 -cycloalkyl; and/or ##STR4## wherein R signifies C.sub.1 -C.sub.20 alkyl or C.sub.5 -C.sub.10 cycloalkyl.
摘要:
Composite moldings of at least one layer of an ABS plastic and at least one layer of a thermoplastic polyurethane having a Shore D hardness of >50, a layer of coupling agent optionally being present between the ABS layer and the thermoplastic polyurethane layer.
摘要:
Polyurea-polyurethane molded articles are produced by reacting organic polyisocyanates, polyols and aromatic amine chain extenders with alkylthio groups with improved impact strength, heat resistance, rigidity (quantified via the flexural modulus) and length of the injection time
摘要:
A process for the production of rigid polyurethane foams having low thermal conductivity is described. This process comprises reacting A) a polyol component comprising: (1) at least one polyester polyol having a molecular weight of from 100 to 30,000 g/mol and containing at least two isocyanate-reactive hydrogen atoms; (2) at least one polyether polyol having a molecular weight of from 150 to 12,500 g/mol and containing at least two isocyanate-reactive hydrogen atoms and at least one tertiary nitrogen atom, and being prepared from a starter compound comprising ammonia or a compound containing at least one primary, secondary or tertiary amino group; (3) at least one polyether polyol having a molecular weight of from 150 to 12,500 g/mol and containing at least two isocyanate-reactive hydrogen atoms, and being prepared from a starter compound comprising water or a polyhydric alcohol; (4) at least one catalyst; (5) water (6) at least one blowing agent; and, optionally (7) auxiliary substances and/or additives; with B) an organic polyisocyanate having an NCO group content of from 20 to 48% by weight. Cyclopentane blown rigid polyurethane foams which exhibit low thermal conductivity and the end-use of such foams as an interlayer in a process for the production of composite components and for filling cavities is also disclosed.