摘要:
The present invention is directed to a reactive mixture for use in preparing a flexible polyurethane foam and to the foams produced therefrom. The reactive mixture broadly comprises an isocyanate reactive composition comprising: A) from more than 0 up to 3 parts by weight per 100 parts by weight of components B) and C) of an amine of the formula: H₂N - R - NH₂ where R is a C₃ to C₁₀ straight or branched alkylene group or a C₄ to C₁₅ alicyclic group, B) from more than 0 up to 40% by weight of a relatively high molecular weight compound containing at least two aromatically bound primary amine groups, and C) from 60 to less than 100% by weight of one or more polyether polyhydroxyl compounds having hydroxyl functionalities of from 2 to 3 and molecular weights of from about 1000 to about 10,000, the percents by weight of component B) and component C) totalling 100%.
摘要:
Rigid polyurethane foams produced by reacting a polyol component having a special composition with an isocyanate component in the presence of a blowing agent, a reaction catalyst and a foam stabilizer with a mold release time of as short as 5.5 minutes or less, have remarkably low thermal conductivity of 12.5 x 10⁻³ Kcal/m.hr.°C or less and a low density and are suitable as heat insulating materials for refrigerators and the like.
摘要:
Flexible polyurethane foams are prepared using certain high molecular weight, high functionality poly-(oxyethylene) compounds as cell openers and softeners. These high functionality polyether polyols have been found to be very effective in opening the cells of the foam, even when used in making foams based on PIPA polyols, which are notoriously closed-celled. They are also quite effective in softening foams made using MDI-based polyisocyanates.
摘要:
Storage stable prepolymers of pure or crude MDI are provided. The prepolymers are prepared by reacting the pure or crude MDI with a polymer polyol comprising (1) 50 to 99% by weight of a polyoxyalkylene polyol having an average functionality in the range 1,000 to 10,000 and comprising 1 to 80% by weight ethylene oxide and (2) 1 to 50% by weight of a polymer of one or more vinyl monomers. Cold cure flexible polyurethane foams produced from such prepolymers have a more open cellular structure relative to prior art materials.
摘要:
Rigid polyurethane foams produced by reacting a polyol component having a special composition with an isocyanate component in the presence of a blowing agent, a reaction catalyst and a foam stabilizer with a mold release time of as short as 5.5 minutes or less, have remarkably low thermal conductivity of 12.5 x 10⁻³ Kcal/m.hr.°C or less and a low density and are suitable as heat insulating materials for refrigerators and the like.
摘要:
This invention relates to crosslinker systems for polyurethane foams and a process for producing such foams. The polyurethanes are prepared by reacting an organic polyisocyanate with an organic compound having active Zerewitenoff hydrogen atoms, e.g., a polyol with an alkoxylated aromatic diamine crosslinker and an acetylenic glycol. Improved properties can be achieved, such as, higher load-bearing at equivalent foam density; higher tear; higher elongation and higher air flow.
摘要:
Polyurethane/polyisocyanurate rigid foams having low thermal conductivity are prepared from isocyanate-terminated quasi-prepolymers prepared from polyester polyols derived from phthalic anhydride or from the transesterification of polyethylene terephthalate scrap.
摘要:
Die Erfindung betrifft Polyurethan-Prepolymere mit endständigen Isocyanatgruppen, enthaltend einen stö chiometrischen Überschuß an einem oder mehreren aro matischen Isocyanaten mit im Mittel zwei bis vier Iso cyanatgruppen pro Molekül als Isocyanatkomponente und ein aus oleochemischen, wenigstens partiell ungesät tigten Triglyceriden durch Epoxidation und anschlie ßende Ringöffnung mit einem Alkohol hergestelltes Polyol als Polyolkomponente, sowie Beschleuniger, Flammschutzzusätze, Treibmittel und gegebenenfalls Verflüssiger, Farbstoffe und/oder Stabilisatoren, wo bei sie als Polyolkomponente ein oder mehrere Ester polyole oleochemischer Herkunft enthalten, die keine freien Epoxidgruppen aufweisen, durch vollständige Ringöffnung von epoxidierten Triglyceriden eines we nigstens teilweise olefinisch ungesättigte Fettsäuren enthaltenden Fettsäuregemisches mit einem oder mehre ren Alkoholen mit 1 bis 12 C-Atomen sowie Umesterung der Triglyceridderivate zu Alkylesterpolyolen mit 1 bis 12 C-Atomen im Alkylrest hergestellt worden sind, ein Verfahren zur Herstellung derartiger Polyurethan- Prepolymere und ihre Verwendung als Ausgangsstoffe für die Herstellung von Polyurethanschäumen.