摘要:
Commercially acceptable spandex can be prepared with greater efficiency, improved consistency and at lower costs from a high-solids content polyurethaneurea polymer solution. The polyurethaneurea is prepared using a combination of 4,4null-MDI and 2,4null-MDI, and an amount of chain extenders and chain terminators such that the polymer solution, prior to spinning, is highly soluble and has an appropriate pre-spun IV and primary amine content.
摘要:
A rheological aid comprising at least one urea derivative preparable by reacting (A) at least one polyisocyanate with (B) at least one polyamine with primary and/or secondary amino groups and at least one primary and/or secondary monoamine and/or water; and its use to prepare pseudoplastic coating materials, adhesives, and sealing compounds.
摘要:
Thermoplastic polyurethanes (TPU) with a low tendency towards surface tackiness of the granules are prepared by applying at least one wetting agent satisfying specified criteria and at least one solid powdering agent to the TPU before and/or after comminution of the TPU.
摘要:
The invention relates to new resins characterised by a content of curable urea derivatives; to new synthetic mortars obtainable using them; to kits for producing the synthetic mortars; to the use of the resins or synthetic mortars in fastening technology; and also to new methods of fastening which comprise the use of those resins or synthetic mortars.
摘要:
A polyaddition compound containing an uretdione group is obtained by solvent-free preparation in an intensive mixer, especially in a single-screw or multiscrew extruder.
摘要:
The present invention provides a flexible polyurethane foam having good resistance to wet heat aging and resistance to ozone deterioration and a speaker edge having an excellent waterproofness comprising such a flexible polyurethane foam. As a polyol, a polyol component obtained by mixing a polyester polyol having an excellent compatibility with polyether polyol such as adipate of a long-chain alkylene glycol having at least 5 carbon atoms with a foaming agent, a catalyst, a foam stabilizer, etc. is reacted with a polyisocyanate to obtain a flexible polyurethane foam having good resistance to wet heat aging and resistance to ozone deterioration. Further, the incorporation of a specific aromatic secondary amine compound, a monofunctionally-terminated compound and an ultraviolet absorbent in the foam composition makes it possible to obtain a flexible foam having better resistance to ozone deterioration and weather resistance. The flexible foam can provide a speaker edge having a small drop of strength and elongation due to compression molding and excellent waterproofness and weather resistance in combination.
摘要:
Isocyanate-functional polyurethane prepolymers and aqueous dispersions therefrom which are useful for the production of flat materials having excellent resistance to alcoholic solvents are described. The prepolymers are prepared by reacting: A) an isocyanate selected from the group consisting of i) an aliphatic and/or a cycloaliphatic isocyanate, ii) a mixture of an aromatic isocyanate and an aliphatic and/or a cycloaliphatic isocyanate, B) a di- or polyhydroxy compound having a number average molecular weight of from 700 to about 16,000, and C) optionally, a dihydroxy and/or polyhydroxyl compound having a number average molecular weight of less than 700, with the provisos that a) at least one of components A), B or C) has a functionality of more than 2 and b) if both component A) and component B) are difunctional, component C) cannot be a trihydroxy component of the formula: Rnull(OH)3 nullwhere R is a saturated straight chain or branched chain aliphatic group of from 2 to 8 carbon atoms.
摘要:
Disclosed are derivatives of isophorone diamine exhibiting a synergistic relationship with other commonly employed chain extenders offering enhanced efficacy with regard to slowing of the polyurea elastomer cure profile, and processes employing their use. According to the invention, extensions of the gel-free and tack-free times are more readily achieved at lower loading levels for these chain extender blends than are afforded through the sole use of the individual molecules.
摘要:
The polyurethane resin produced by reacting a component composed mainly of an active hydrogen-containing compound with a component composed mainly of an organic polyisocyanate compound which contains a backbone structure represented by the formula: 1 in an amount of 20% by weight or higher, exhibits a high gas-barrier property and a high adhesion property. Accordingly, the present invention provides: (A) a two-part liquid curable polyurethane resin composition having an excellent adhesion property to various polymers, papers, metals, etc., especially after boiling and retort treatments, and an adhesive for gas-barrier laminate containing such a composition; (B) a heat-curing gas-barrier polyurethane resin useful as a packaging material for foodstuffs or drugs for the purpose of preserving contents thereof by preventing various gases from penetrating therethrough, which is capable of maintaining its high gas-barrier property; and (C) a paint having excellent properties such as rust-proofing property, corrosion resistance and aesthetic decorating property that are inherent to polyurethane resin, and being applicable to packaging materials for foodstuffs or drugs that are required to show a high gas-barrier property by shielding various gases.