摘要:
A polyurethane foam and associated production process, in particular flexible to semi-hard block foams or soft molded foams, using polyesters or polyethers as polyols. A carbamate, or a mixture of carbamates, is used simultaneously as propellant and as catalyst, wherein the carbamate or the carbamates have the general Formula I wherein: R1 and R2 represent the same or different alkyl radicals, R3 and R4 represent the same or different radicals and denote hydrogen or alkyl radicals, R5 denotes hydrogen, an alkanol radical, a polyether monool radical or the alkyl radical, characterized by X and n represents 2 or 3.
摘要:
The present invention relates to a process for the production of semi-rigid foams containing urethane groups which exhibit very good flow properties during the production process. These semi-rigid foams are produced by reacting a reaction mixture of:1) polyisocyanates,2) organic compounds containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight in the range from 400 to 10,000, and3) water and/or organic blowing agents.In particular, the polyisocyanates comprise a mixture of:a) 55 to 87% by weight, based on 100% by weight of the mixture, of 4,4'-diphenylmethane diisocyanate,b) 8 to 40% by weight, based on 100% by weight of the mixture, of 2,4'-diphenylmethane diisocyanate,c) 0.1 to 4% by weight, based on 100% by weight of the mixture, of 2,2'-diphenylmethane diisocyanate, andd) 5 to 35% by weight, based on 100% by weight of the mixture, of polyphenyl polymethylene polyisocyanates.
摘要:
This invention relates to a process for the production of cold-setting flexible polyurethane foam useful for damping sound comprising reacting a polyisocyanate in the presence of water with (a) at least one polyether having an OH number of from 20 to 60 and containing at least two OH groups, wherein said polyether is based on 75 to 95% by weight propylene oxide and 5 to 25% by weight ethylene oxide; (b) a polyether or polyester having an OH number of from 150 to 400 and containing at least two OH groups; and (c) a polyether different from components (a) and (b) having an OH number of from 20 to 200 and containing at least two OH groups, wherein said polyether is based on propylene oxide and ethylene oxide and has an ethylene oxide content above 50% by weight based on the total amount of propylene oxide and ethylene oxide.
摘要:
A method for producing an active substance-containing polyurethane plaster for transdermal application is described, said plaster containing at least one active substance at a highly accurate declared dose. In the described method, a solvent-free active substance-containing polyurethane is produced by reactively coating a solvent-free active substance-containing polyurethane material (40), which is mixed in a coating unit (60) immediately before or during the application process, onto an elastic backing foil (20) that has been rendered non-extensible at least in the direction in which the applied polyurethane material is processed by means of a supporting, adhering auxiliary foil (30) which is at least mono-axially non-extensible.
摘要:
A polyurethane molding is composed of at least two different polyurethane materials, namely of a polyurethane gel and a polyurethane foam. The foam and the gel are arranged in layers one above another so that both materials act together as spring or damping element with respect to a load in the transverse direction. These moldings may preferably be used as seat cushions.
摘要:
The invention relates to the use of expandable graphite having a starting temperature greater than or equal to 150° C. for increasing the sound absorption within a sound absorption foam material foamed with the expandable graphite, wherein the foam material is a polyurethane foam material. An associated sound absorber having a sound absorption foam material made of a polyurethane integral foam or polyurethane flexible foam, which is open-cell at least in the core region thereof, has a density greater than or equal to 120 g/l and a content of at least 5 wt % of expandable graphite to 100 parts by weight of isocyanate-reactive components, in particular polyol. The sound absorber can preferably be used for sound absorption in engine compartments of motor vehicles. The sound absorber can also be used very advantageously inside relatively complex components and in the design-dependent cavities of machines.
摘要:
The present invention is directed to a rigid, molded foam produced by reacting: a) one or more organic polyisocyanates, with b) a polyol blend comprising i) 100 parts by weight of a mixture comprising: 1) from 30 to 80 parts by weight of one or more polyethers having hydroxy functionalities of 2 or 3 and molecular weights of from about 1,000 to about 8,000, the polyethers further being characterized as containing no nitrogen atoms and not being filled polyethers, 2) from 10 to 50 parts by weight of one or more adducts of toluene diamine and an alkylene oxide, the adduct having a molecular weight of from about 350 to about 700, 3) from 0 to 15 parts by weight of one or more di- or trialkanol amines, with the amounts of components 1), 2) and 3) totaling 100 parts, and c) from about 0.1 to about 4 parts by weight per 100 parts by weight of component b) of a silicone cell-opening surfactant and d) from 1 to 7 parts by weight of water, and e) from 0.1 to 2 parts by weight of at least one tertiary amine catalyst; wherein the reaction mixture contains no auxiliary blowing agents and wherein the amount of polyisocyanate is such that the isocyanate index is from 95 to 120.
摘要:
The present invention relates to a process for the preparation of low-density flexible polyurethane foams comprising reacting, in a closed mold, a mixture comprising polyisocyanates; compounds containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight in the range from about 400 to about 10,000; water as blowing agent; optionally, compounds containing at least two isocyanate-reactive hydrogen atoms and having a molecular weight in the range from 32 to 399 as chain-extending and crosslinking agents; and optionally, one or more known auxiliaries and additives, wherein one or more of the reaction mixture components is heated before foaming to a temperature of at least 40.degree. C.
摘要:
This invention relates to liquid urethane-modified polyisocyanate compositions obtained by reaction of polyisocyanates or polyisocyanate mixtures of the diphenylmethane series containing from about 50 to about 100% by weight diisocyanatodiphenylmethane isomers with substoichiometric quantities of polyether polyol compositions having an average hydroxyl equivalent weight of about 500 to 3000 and an average hydroxyl functionality greater than about 4, optionally followed by mixing the initially formed reaction product with urethane-free polyisocyanates or polyisocyanate mixtures of the diphenylmethane series containing from about 40 to about 100% by weight diisocyanatodiphenylmethane isomers. This invention also relates to a process for the preparation of such polyisocyanate compositions. The invention further relates to the use of such compositions as the polyisocyanate component in the production of flexible polyurethane foams.
摘要:
Molding compositions are provided that include a) one or more polyisocyanates, b) one or more polyols, c) one or more catalysts catalysing the reaction between polyisocyanate and polyol, d) one or more pyrogenically produced oxides of a metal or of a metalloid, and e) at least one or more siloxanes.