摘要:
The present invention relates to mixtures containing 1) polycarbonates and 2) specific polymers of C.sub.10 -C.sub.40 -alkyl (meth)acrylates and if appropriate styrenes or C.sub.1 -C.sub.4 -alkyl methacrylates, and if appropriate customary additives, the preparation of these mixtures and their use for the production of petrol-resistant shaped articles.
摘要:
The invention relates to polyacrylates corresponding to formula (I) ##STR1## to their production in a quasi-ionic polymerization and to their use as monofunctional chain terminators, optionally in combination with typical other chain terminators, for the production of aromatic polycarbonates.The invention also relates to the polycarbonates or polycarbonate mixtures obtained using the compounds corresponding to formula (I) and to their use as additives for other thermoplastic polycarbonates.
摘要:
This invention relates to a process for the production of aromatic polycarbonates from cyclic aromatic carbonate oligomers in the presence of aprotic organic solvents at low temperatures.
摘要:
Thermoplastic polydiorganosiloxane/polycarbonate block copolymers based on dihydroxydiphenylcycloalkanes corresponding to the following general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 independently represent hydrogen, halogen, preferably chlorine or bromine, C.sub.1 -C.sub.8 alkyl, C.sub.5 or C.sub.6 cycloalkyl, C.sub.5 -C.sub.10 aryl or C.sub.7 -C.sub.12 aralkyl, preferably phenyl-C.sub.1 -C.sub.4 -alkyl, in particular benzyl: m represents an integer of from 4 to 7, preferably 4 or 5;R.sup.3 and R.sup.4 may be chosen individually for each X and independently represent hydrogen or C.sub.1 -C.sub.12 alkyl; andX represents carbon; with the proviso that R.sup.3 and R.sup.4 both represent alkyl on at least one atom X,having an average molecular weight M.sub.w (weight average) of 10 000 to 300 000, a content of aromatic polycarbonate of 21 to 99.5% by weight and a content of polyorganosiloxane of 79 to 0.5% by weight.
摘要:
Copolymers of blocks of polymers of cyclic aliphatic carbonates, cyclic aliphatic esters or cyclic aliphatic carbonates and cyclic aliphatic esters on the one hand and blocks of polymers of cyclic aromatic carbonates on the other hand and a process for their production by multistage polymerization, in which a block polymer is initially prepared from the aliphatic monomer and the aromatic polymer is produced in the presence of this block.
摘要:
A sealing arrangement, which is particularly suitable for flat flange connections, has an annular, metallic base body (1). Connected to the metallic base body (1) at both sides are soft material supports (2). The base body (1) has ring teeth (3,4) which run around radially at the inside and/or at the outside. The ring teeth (3,4), in the installed state, permit punctiform metallic contact and also have a spring characteristic. The spring characteristic of the ring teeth (3,4) is selected such that, in a first embodiment, after the removal of the seal from the flanges, the tooth height corresponds substantially to the height before the installation. The region of the base body (1) which is covered by the soft material supports (2) also has angular ring teeth (5). The ring teeth (5) have a spring characteristic, wherein after the removal of the seal, the ring teeth (5) spring back to at least 75% of the original state. In a further embodiment, the ring teeth (5) which are covered by the soft material support (2) are partially plastically deformable.
摘要:
The sealing arrangement for a flat flanged joint comprising a preferably metallic base body 1 has bearing surfaces 7, 7′ on each of its two sides for ring-shaped supports (11, 12) made of a soft material, the bearing surfaces (7, 7′) being flat over a large area and being situated essentially directly opposite to each other, at least one ring tooth (2, 3) being provided in the inner radial area of each bearing surface and preferably at least one ring tooth (5, 6) being also provided in the outer radial area of each bearing surface, said soft material supports each being fixed on the bearing surfaces (7, 7′), the ring teeth (2, 3, 4, 5, 6), when the arrangement is assembled, coming to rest on the flange surfaces (14, 15), and the soft material supports (11, 12) being at least inwardly limited by the ring teeth (2, 3), wherein the wall of the base body (1) has a low thickness of only 0.2 to 2.0 mm, preferably 0.3 to 1.2 mm, and the ring teeth are shaped by stamping in such a way that the whole wall has an angular or wave-shape configuration, and a punctual metallic contact with the flange surfaces (14, 15) is enabled.
摘要:
A sealing arrangement, which is particularly suitable for flat flange connections, has an annular, metallic base body (1). Connected to the metallic base body (1) at both sides are soft material supports (2). The base body (1) has ring teeth (3,4) which run around radially at the inside and/or at the outside. The ring teeth (3,4), in the installed state, permit punctiform metallic contact and also have a spring characteristic. The spring characteristic of the ring teeth (3,4) is selected such that, in a first embodiment, after the removal of the seal from the flanges, the tooth height corresponds substantially to the height before the installation. The region of the base body (1) which is covered by the soft material supports (2) also has angular ring teeth (5). The ring teeth (5) have a spring characteristic, wherein after the removal of the seal, the ring teeth (5) spring back to at least 75% of the original state. In a further embodiment, the ring teeth (5) which are covered by the soft material support (2) are partially plastically deformable.
摘要:
The invention relates to a segment for a sealing arrangement, wherein a plurality of such segments can be attached to the circumference of a sealing ring for centering the sealing arrangement while the latter is installed between two flanges. Each segment comprises a curved centering flank, a further flank serving as a point of attack for a rotating mechanism, and a third flank for attachment of the segment to the sealing ring. The segment is provided as a one-pieced unit of a relatively small size. The segments can be mounted irrespective of the nominal pressure and the nominal diameter. This allows for an inexpensive manufacture of the sealing arrangement. Various embodiments of segments are described.