摘要:
Disclosed are compositions that comprise water and a polyether polyol derived from sucrose and an alkylene oxide, as well as polyurethane foam systems comprising such compositions, methods for their production, and the resulting polyurethane foams.
摘要:
A composition comprising (a1) a polyether polyol, (a2) a polyolefine polyol and (a3) a polyester polyol obtainable by epoxidation of an unsaturated fatty acid ester and subsequent ring-opening reaction with a compound containing active hydrogen, can be used for the preparation of PUR foam which distinguishes by low-temperature flexibility and low dielectric loss and is suitable for filling the gap between the condenser core and the outer composite or porcelain insulator in the manufacture of resin impregnated paper (RIP) bushings.
摘要:
This invention relates to polybutadiene modified polymer polyols which comprise one or more base polyols, at least one preformed stabilizer, one or more ethylenically unsaturated monomers, and polybutadiene, in the presence of at least one free radical polymerization catalyst, and optionally, one or more chain transfer agents. The polybutadiene present in these polybutadiene modified polymer polyols may be carried into the polymer polyol through the preformed stabilizer, by a polybutadiene containing component that is added separately from the preformed stabilizer to the polymer polyol, or a combination thereof, with the total amount of polybutadiene ranging from 0.03 to 1.0% by weight of polybutadiene, based on 100% by weight of the polymer polyol. The present invention also relates to processes for preparing these polybutadiene modified polymer polyols, to foams prepared from these polybutadiene modified polymer polyols, and to processes for producing foams from these polybutadiene modified polymer polyols.
摘要:
Polyols are produced by an alkoxylation process in which a vegetable oil containing hydroxyl functional groups is combined with a DMC catalyst to form a mixture, the DMC catalyst is then activated by adding ethylene oxide and/or propylene oxide to the vegetable oil/catalyst mixture, and ethylene oxide and propylene oxide are added to the mixture containing activated DMC catalyst in amounts such that the total of percentage of ethylene oxide in the polyol plus percentage of primary hydroxyl groups in the polyol produced is from 50 to 77% and the percentage of primary hydroxyl groups is at least 30% but less than 50%. These polyols are useful for the production of molded polyurethane foams, particularly, hot-cure molded polyurethane foams.
摘要:
Die vorliegende Erfindung betrifft ein Koppelverfahren zur Herstellung von Polyetherpolyolen ausgehend von hochfunktionellen, bei Reaktionsbedingungen festen bzw. hochviskosen Starterverbindungen und monofunktionellen, bei Reaktionsbedingungen flüssigen Starterverbindungen mit Zerewitinoff-aktiven Wasserstoffatomen.
摘要:
Methods comprising: providing an aromatic polyisocyanate and a polyol; and reacting the aromatic polyisocyanate and the polyol in the presence of a blowing agent and a catalyst to form a rigid polyurethane foam; wherein the blowing agent comprises water and a hydrocarbon having 3 to 8 carbon atoms; and wherein the polyol comprises a poiyether polyol of a mean functionality of 4.5 or more obtained by adding an alkylene oxide to a mixture of diaminodiphenylmethane and polymethylene polyphenylamine where n=0 is 50 to 70% by weight and n≥1 is 30 to 50% by weight, wherein the amount of a compound of n=4 relative to said mixture is 2.5% by weight or more, as expressed by the formula (1):.
摘要:
A viscoelastic polyurethane foam is the reaction product of at least one natural oil derived polyol and at least one aromatic compound having an average of more than one isocyanate group. A viscoelastic polyurethane foam has an air flow of at least about 0.5 l/s, wherein the foam is formed in the substantial absence of copolymer polyol and has not (yet) been mechanically reticulated and is preferably prepared using at least one natural oil derived polyol, more preferably in an amount of at least about 20 weight percent of the polyols used. A process of preparing a viscoelastic foam, comprises steps of (A) forming a reaction mixture including at least one polyol, at least one polyisocyanate, water, at least one catalyst wherein a the polyol comprises at least one natural oil derived polyol; and (B) subjecting the reaction mixture to conditions sufficient to result in the reaction mixture to expand and cure to form a viscoelastic polyurethane foam. In another embodiment, a process comprises steps of (a) forming a natural oil derived polyol composition comprising at least one natural oil derived polyol and water; (b) admixing at least one gelling catalyst and at least one blowing catalyst with the natural oil derived polyol composition to form a catalyst polyol admixture; (c) supplying an isocyanate in an amount corresponding to an isocyanate index for a pMDI of at least about 65 and at most about 95 or, when the isocyanate is a TDI or MDI or combination thereof, at least about 80 and at most about 105; and (c) admixing the isocyanate with the catalyst polyol admixture.
摘要:
A process of forming a polyol includes the steps of providing an alkylene oxide, providing an initiator composition having an average functionality of at least four, and providing an alkaline earth metal hydroxide and an amine. The process also includes the step of reacting the initiator composition and the alkylene oxide in the presence of the alkaline earth metal hydroxide and the amine to form the polyol. This allows the polyol to have consistent chain length and be formed with increased speed and in high yield, while reducing costs and maximizing efficiency. The polyol is reacted with an isocyanate and used to form a polyurethane article.
摘要:
Die Erfindung betrifft verstärkte Polyurethanharnstoff-Elastomere mit einem bestimmten Harnstoff- und einem bestimmten Urethananteil sowie daraus herstellbare flächige Polyurethanformkörper mit verbesserter Zähigkeit und verbesserten Schwindungseigenschaften sowie deren Verwendung.
摘要:
The subject invention provides polyurethane foam and a method of purifying polyether polyols of non-volatile impurities for use in forming the polyurethane foam. The method includes the step of providing a crude polyether polyol having a non-volatile impurity present therein. The crude polyether polyol is contacted with an adsorbent selected from at least one of activated carbon, diatomaceous earth, charcoal, attapulgite, and clay to remove the impurity and filtered to form a purified polyether polyol. The filtering of the crude polyether polyol is carried out through a filter media that is used both in a pre-filtering step prior to adding the adsorbent and the filtering step to remove the adsorbent to reduce losses of the purified polyether polyol because of its high viscosity. The purified polyether polyol is then used to form a polyurethane foam having improved stability.