摘要:
The invention relates to a method of preparation for polymers, particularly binders for powder coatings and powder coatings which are prepared as a solution in a supercritical fluid phase. Binders for powder coatings are prepared from at least two ethylenically unsaturated monomers capable of free-radical or ionic copolymerization, and conventional initiators and regulators in supercritical fluids, whereby polymerization is carried out in the homogeneous phase, and, after the reaction has ended, either the composition or the phase parameters of the mixture are altered so that at least two phases with supercritical fluid are obtained, and the phase containing predominantly polymer is separated and the polymer is separated as a powder from the sc fluid by depressurization or the polymer phase is further processed under supercritical phase conditions to the powder coating.
摘要:
A process for the production of 3-hydroxy-1,3,5(10)-estratrien-17-one by pyrolysis of 1,4-androstadiene-3,17-dione in the presence of 1,2,3,4-tetrahydronaphthalene as hydrogen donor is described, by 1,2,3,4-tetrahydronaphthalene, preheated to a temperature of 450.degree.-850.degree. C., in a mixing zone being mixed with a solution, heated to a temperature of up to 300.degree. C., of 1,4-androstadiene-3,17-dione, in 1,2,3,4-tetrahydronaphthalene, the mixture being heated in a pyrolysis zone at a retention time of 0.001 to 60 seconds to temperatures of 450.degree.-700.degree. C. and the product leaving the pyrolysis zone being cooled off, which is characterized in that the pyrolysis is performed under a pressure of 3.5.times.10.sup.6 to 3.times.10.sup.8 Pa.
摘要:
The present invention relates to a process for the radical polymerization or copolymerization of ethylene under high pressure in the presence of at least one polymerization initiating-controlling compound capable of providing, by decomposition under the polymerization or copolymerization conditions: at least one initiating free radical (Z) which carries at least one site for initiating the (co)polymerization; and at least one stable free radical (SFR) which carries at least one site exhibiting the stable radical state and which is stable under the polymerization conditions, with, in total, as many initiating sites as sites exhibiting the stable radical state.
摘要:
Polymers are obtained by a radical (co)polymerization of ethylene under high pressure in the presence of at least one initiating free radical (Z*) and of at least one controlling stable free radical (SFR*) which comprises the indoline nitroxide backbone represented by the formula (I). A is a hydrocarbonaceous chain forming an aromatic ring with the two carbon atoms to which it is attached, this ring being able to carry substituents or being able to carry one or more rings placed side by side, which rings are aromatic or aliphatic and optionally substituted, the carbon atoms forming the nitrogenous ring and in the alpha- and beta-position with respect to the nitrogen atom being, able to carry hydrogen atoms or substituents.
摘要:
A radical (co)polymerization of ethylene is carried out under high pressure in the presence of at least one initiating free radical (Z•) and of at least one controlling stable free radical (SFR•) which comprises the indoline nitroxide backbone represented by the formula (I). A is a hydrocarbonaceous chain forming an aromatic ring with the two carbon atoms to which it is attached, this ring being able to carry substituents or being able to carry one or more rings placed side by side, which rings are aromatic or aliphatic and optionally substituted, the carbon atoms forming the nitrogenous ring and in the alpha- and beta-position with respect to the nitrogen atom being able to carry hydrogen atoms or substituents.
摘要:
A product which is suitable for producing films and moldings and for use as a coating agent comprises a cyano-containing copolymer A based on ethylene composed of(a) predominant proportions of the structural unit of ethylene,(b) minor proportions of the structural unit of the general formula Ia ##STR1## where R.sup.1 is hydrogen or C.sub.1 -C.sub.4 -alkyl, and (c) optional structural units derived from other comonomers,which is prepared by reacting a base copolymer B formed from predominant proportions of ethylene, minor proportions of an .alpha., .beta.-unsaturated carboxylic ester of the general formula Ib ##STR2## where R.sup.2 is C.sub.1 -C.sub.8 -alkyl, and further, optional comonomers, with ammonia at 120.degree.-280.degree. C. and 150-2,500 bar.