摘要:
The invention relates to a process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, via reaction of one or more polyetherdiols with a stoichiometric excess of α,ω-dihydropoly-dimethylsiloxanes and at least one tertiary amine as catalyst, which comprises, after completed reaction of the alcohol component, continuing the reaction in the presence of small amounts of water until no remaining ≡Si(H) groups are detectable by a gas-volumetric method.
摘要:
The invention relates to a process for the preparation of SiOC-linked, linear polydimethylsiloxane-polyoxyalkylene block copolymers having (AB) repeat units, via reaction by methods known per se of polyetherdiols with a stoichiometric excess of α,ω-dihydropolydimethylsiloxanes, in the presence of one or more compounds of elements of main group 13 and/or of transition group 3 as catalyst, which comprises, after completed reaction of the alcohol component, continuing the reaction until no remaining ≡Si(H) groups are detectable by a gas-volumetric method, and also to the compounds thus prepared, and to their use as surfactant additives for the production of polyurethane ether foams.
摘要:
A process for fabricating dental form pieces for dental restoration and replacement parts is provided and includes the step of applying a material, on a firm support or a fluid medium, by a three dimensional plotting technology in a layer by layer manner. The material has micro cords and/or micro drops which include at least one of a meltable, polymerizable, polycondensable, and polyaddable constituent element that is an unfilled monomer, a reinforced monomer, oligomer, polymer, or a ceramic element. The process also includes the step of hardening the applied material by cooling of the material, chemical reaction, polymerization with thermal handling, or polymerization by irradiation of the material with UV or visible light.
摘要:
The present invention relates to the use of a reactive amine catalyst, in particular diethylaminoethoxyethanol and/or diethylethanolamine, in aqueous or organic solutions for producing flexible polyurethane foams having an increased recatalysis stability, and also a catalyst combination containing at least one reactive amine catalyst which can be used according to the invention; and at least one organic potassium, tin, bismuth and/or zinc compound; and/or at least one tertiary amine selected from the group consisting of triethylenediamine, triethylamine and/or silamorpholine; and/or at least one acid-blocked derivative of a tertiary amine.
摘要:
The invention relates to a cutting oil comprising A) at least one polyalkylene glycol and B) optionally solvent and C) optionally further auxiliary materials and additives, and to its use for sawing polyurethane foams.