摘要:
The present invention relates to new catalysts and production thereof as well as the preferred use thereof in the production of polyisocyanate polyaddition products. The described catalysts are tetravalent tin compounds with at least one ligand bonded via at least one oxygen atom or sulfur atom and containing at least one nitrogen atom.
摘要:
The invention relates to novel molded polyurethane elastomer parts made of diphenylmethane diisocyanate-based NCO-functional prepolymers and diphenylmethandiamine blocked with metal salts and to a method for producing same.
摘要:
Isocyanate mixtures comprising: (a) NCO prepolymers having an NCO content of 1.5 to 18 wt. %; and (b) 1 to 40 wt. % of monomeric 2,2′-diisocyanatodiphenylmethane, based on the isocyanate mixture; wherein the isocyanate mixture has a total NCO content of from 2 to 22 wt. %; polyisocyanate polyaddition products prepared therefrom; and methods of making the same.
摘要:
The invention relates to the use of polyurethane casting compounds for producing light-resistant compact or expanded polyurethane or polyurethane urea bodies that are characterized by exceptionally good mechanical and visual properties and particularly have a very high heat shape retention.
摘要:
The present invention relates to new catalysts and production thereof as well as the preferred use thereof in the production of polyisocyanate polyaddition products.
摘要:
By automatically estimating the focus status of individual substrates or lots on the basis of focus-specific tool information obtained from the exposure tool, such as tilt angle ranges used during the automatic focusing procedures, possible hot spot errors may be detected highly efficiently prior to releasing the substrates to a subsequent etch process. Consequently, yield losses may be reduced. Moreover, possible error sources for hot spot errors may be identified.
摘要:
Polyurethane prepolymers are described which are prepared from 2,4′-diiso-cyanate diphenylmethane (2,4′-MDI), a polyol component and an aliphatic diisocyanate. These prepolymers can be cured with aliphatic, cycloaliphatic and/or aromatic amines to form a cured urethane elastomer. In comparison to cured urethane elastomers based on monomeric 2,4′-MDI, these prepolymers provide elastomers with extended pour life, i.e. they exhibit a slower rate of viscosity buildup after curative and prepolymer are mixed which results in a reduced propensity to crack during the curing process and gives the opportunity to cast larger parts. In comparison to polyurea/urethanes prepared from cured TDI-prepolymers and which optionally include H12-MDI, the prepolymers of the invention have better health and safety aspects.