摘要:
By adding substances corresponding to the following general formula I ##STR1## in which X=O, S or N--R.sub.5 ; R.sub.1 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, C.sub.5 -C.sub.12 -cycloalkyl or C.sub.5 -C.sub.12 -cycloalkenyl; R.sub.2 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.12 -alkenyl, phenyl or C.sub.1 -C.sub.4 -alkylene phenyl; R.sub.3 =hydrogen, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, acryl formyl or acetyl; R.sub.4 and R.sub.5 =same or different, C.sub.1 -C.sub.19 -alkyl, C.sub.2 -C.sub.19 -alkenyl, phenyl, C.sub.1 -C.sub.4 -alkylene phenyl, acryl, C.sub.5 -C.sub.12 -cycloalkyl or C.sub.5 -C.sub.12 -cycloalkenyl; R.sub.4 and R.sub.5 may also form a C.sub.4 -C.sub.7 -ring which may optionally contain an oxygen atom in ether form and the radicals R.sub.1 and R.sub.2 may form a C.sub.5 -C.sub.12 -alkylene bridge or a C.sub.5 -C.sub.12 -alkenylene bridge, the radicals R.sub.1 and R.sub.4 may form a C.sub.2 -C.sub.9 -alkylene bridge and the radicals R.sub.1 and R.sub.3 may form a C.sub.3 -C.sub.10 -alkylene bridge; where R.sub.1 and R.sub.2 are attached, the ring formed may be bridged by a C.sub.1 -C.sub.4 -alkylene bridge and the ring systems formed may be substituted by the radical R.sub.6 which represents hydrogen, C.sub.1 -C.sub.5 -alkyl or C.sub.2 -C.sub.5 -alkenyl, in quantities of from 0.05 to 3% by weight, based on 100 parts by weight of monomer, to the aqueous emulsion polymerization of chloroprene at the beginning of the reaction, during or after polymerization, but at the latest before the residual monomers are removed, high-viscosity polychloroprenes characterized by excellent processing behaviour and product properties are obtained.
摘要:
There is disclosed an electrically conductive pigment containing 20 to 95% by weight of a component A comprising one or more conductive platelet-like pigments and 5 to 80% by weight of a component B comprising one or more conductive needle-shaped or fibrous pigments.
摘要:
An improved process for the preparation of polychloroprene by the emulsion (co)polymerization of chloroprene and optionally other monomers capable of copolymerization with chloroprene, using a peroxo activator, and subsequent working up of the product by stopping the reaction, stabilizing, degassing and isolating the product, characterized in that polymerization is carried out in the presence of dithiocarbamates and/or xanthates and 0 to 0.5% by weight of sodium .beta.-anthraquinone sulphonate.
摘要:
An elastomeric mass of polychloroprene sol and polychloroprene gel in proportions in the range of 95:5 to 25:75% by weight in which the polychloroprene sol is free from sulphur and the polychloroprene gel used is a sulphur-containing gel with xanthate or carbamate functions has better processing characteristics than the pure sol component without the expected deterioration in the mechanical properties of the vulcanisates prepared from the mass.
摘要:
This invention relates to xanthogen disulphides of the formula ##EQU1## in which R is the same or different and denotes the following groups: ##EQU2## wherein X = H, alkyl, aryl, aralkyl or halogenn = 1 to 20,A process for preparing them, a process for polymerising dienes and monoethylenically unsaturated copolymerizable monomers in the presence of these particular xanthogen disulphides and to vulcanisable rubber mixtures consisting of an uncross-linked benzene soluble chloroprene homopolymer or copolymer which is prepared in the presence of said xanthogen disulphides.
摘要:
This invention relates to xanthogen disulphides of the formula ##STR1## in which R is the same or different and denotes the following groups: ##STR2## WHEREIN X = H, alkyl, aryl, aralkyl or halogenn = 1 to 20,A process for preparing them, a process for polymerizing dienes and .alpha.-olefines in the presence of these particular xanthogen disulphides and to vulcanizable rubber mixtures consisting of an uncross-linked benzene soluble chloroprene homopolymer or copolymer which is prepared in the presence of said xanthogen disulphides.
摘要:
Toluene-soluble, sulphur-modified polychloroprene is obtained by emulsion copolymerization of chloroprene, sulphur and optionally further monomers which are copolymerizable with chloroprene and sulphur using a peroxy activator and subsequent working-up by stabilizing, stopping, degassing and isolating without separate peptization, in that polymerization is carried out in the presence of dithiocarbamates and/or xanthogenates and the activator is metered in continuously or batch-wise during the course of polymerization.
摘要:
A freeflowing rubber mixture which is stable against coalescence and cohesion comprising a vulcanizable rubber in powder form and a minor amount of an acrylonitrile polymer as a separating agent.
摘要:
This invention relates to xanthogen disulphides of the formula ##STR1## in which R is the same or different and denotes the following groups: ##STR2## wherein X = H, alkyl, aryl, aralkyl or halogenn = 1 to 20,A process for preparing them, a process for polymerizing dienes and .alpha.-olefines in the presence of these particular xanthogen disulphides and to vulcanizable rubber mixtures consisting of an uncross-linked benzene soluble chloroprene homopolymer or copolymer which is prepared in the presence of said xanthogen disulphides.