摘要:
The present invention relates to a process for the preparation of bis-carbonic acid monoaryl esters of polyester-diols, lengthened via --OCOO-- groups, characterized in that polyester-diols with molecular weights Mn (number-average) of over 250, preferably over 600, are heated with carbonic acid bis-aryl esters at temperatures between about 100.degree. C. and 200.degree. C., preferably between about 110.degree. C. and 180.degree. C., in vacuo below about 35 mm Hg, preferably between about 25 and 1 mm Hg, in the presence of catalysts, less than one mol of carbonic acid bis-aryl ester being employed per mol of OH group of the polyester-diol and the hydroxyaryl compounds formed being distilled off.The invention further relates to the bis-carbonic acid aryl esters of polyester-diols lengthened via --OCOO-- groups.
摘要:
This power circuit-breaker has at least one cylindrically constructed arcing chamber which is provided with a stationary contact, with a moving contact and with a quenching zone between the two contacts. A shaft of the moving contact is permanently connected to a blowout volume which is closed off on the stationary contact side by an insulating nozzle through which at least one flow channel passes. The arcing chamber has a first compression volume which is operatively connected to the blowout volume and to a second compression volume. It is intended to provide a power circuit-breaker in which the blowing-out of the arc with pure SF.sub.6 gas is made stronger. This is achieved by providing a moving auxiliary piston between the first compression volume and the second compression volume and by the auxiliary piston being connected to the moving contact via a direction-changing device.
摘要:
A transparent thermoplastic molding composition containing:A) 30 to 94% of a thermoplastic polycarbonates based on 2,2-bis-(4-hydroxyphenyl)-propane, andB) 6 to 70% of a resin-like vinyl polymer which contains structural units corresponding to formula (Ia) ##STR1## in which R.sup.1 is H or CH.sub.3,R.sup.2 is C.sub.1-4 alkylene andR.sup.3 is C.sub.1-4 alkyl,is disclosed. The composition is particularly suitable for the preparation of optical storage media.
摘要:
An improved process for the preparation of .alpha.-methylstyrene polymers by aqueous emulsion polymerization in which a styrene monomer mixture is first polymerized in a quantity of from 0.5 to 8% by weight of the total quantity of monomers and thereafter an .alpha.-methylstyrene monomer mixture is polymerized batchwise or semi-continuously.
摘要:
Free-flowing, stable dispersions of crosslinked rubbers in the form of discrete particles having an average diameter of 0.1 to 3 .mu.m in organic liquids, containingI) up to 60% by weight (based on the dispersion as a whole) of a crosslinked, rubber-like, particulate graft polymer of a) a crosslinked silicone rubber as core and crosslinked acrylate rubber b) graft polymerized thereon as the rubber andII) a liquid, organic N,N-substituted amide as the continuous organic phase,and a process for their production.
摘要:
The invention relates to high-impact polyether sulfone molding compositions containing aromatic polyether sulfones, diene graft polymers and, optionally, other thermoplastic resins, at most half the aromatic polyether sulfone being replaceable by other thermoplastic resins.
摘要:
Plastics suitable for use as thermoplastic moulding compositions obtained fromA) a thermoplastic vinyl polymer andB) a mixture ofB1) a copolymer of 35 to 49% by weight of maleic acid anhydride and 65 to 51% by weight of styrene andB2) a copolymer of styrene, .alpha.-methylstyrene or mixtures thereof on the one hand and acrylonitrile on the other having an acrylonitrile content of 35 to 60% by weight [based on B2)]and a process for their preparation.
摘要:
Polymer mixtures ofA) 5 to 98 parts by weight and preferably 20 to 95 parts by weight of an aromatic polycarbonate,B) 2 to 70 parts by weight and preferably 5 to 60 parts by weight of a graft polymer of resin-forming monomers on a particulate diene and/or acrylate rubber having an average particle diameter (d.sub.50) of from 80 to 800 nm and preferably from 100 to 600 nm,C) 0 to 80 parts by weight and preferably 0.5 to 40 parts by weight of an uncrosslinked thermoplastic vinyl copolymer having a softening temperature above 30.degree. C.,in which either the resin-forming monomers in B) or a monomer of the thermoplastic vinyl copolymer C) or both have contained a monomer corresponding to formula (I) ##STR1## in which R.sup.1 =H, CH.sub.3 ; R.sup.2 =C.sub.1-8 alkylene; R.sup.3 =C.sub.1-4 alkylene, in such a quantity that the structural elements containing oxetanyl groups emanating therefrom make up from 0.05 to 5% by weight and the use of the thermoplastic molding compounds.
摘要:
Thermoplastic molding composition comprisingA. 5 to 99% by weight (based on A+B) of a polycarbonate based on substituted dihydroxydiphenyl cycloalkanesB. 1 to 95% by weight (based on A+B) of a graft polymer prepared by a special process of5 to 90 parts by weight of a mixture ofB.1.1. 50 to 95 parts by weight styrene, .alpha.-methyl styrene, C.sub.1-4 alkyl- or halogen-nucleus-substituted styrenes, C.sub.1-8 alkyl methacrylates, C.sub.1-8 alkyl acrylates or mixtures thereof andB.1.2. 5 to 50 parts by weight acrylonitrile, methacrylonitrile, C.sub.1-8 alkyl methacrylates, C.sub.1-8 alkyl acrylates, maleic anhydride, C.sub.1-4 alkyl-N-maleic imides, phenyl-N-maleic imides or mixtures thereof onB.2. 10 to 95 parts by weight of a diene rubber having an average particle diameter d50 of from 0.09 to 1 .mu.m and a gel content of more than 50% by weight and optionally at least one other thermoplastic resin which replaces up to 75% by weight of the polycarbonate A.
摘要:
This invention relates to new thermoplastic moulding compounds of polyamides, graft polymers containing tert.-butylacrylate in the shell and optionally also rubber polymers as impact strength modifiers.