摘要:
A process is described for the preparation of photopolymerizable compositions, wherein the photopolymerizable compositions can be photopolymerized by the irradiation of emission lines of differing wavelength from a UV/VIS laser light source, and contain a photopolymerizable compound and at least two photoinitiators, by adjusting the sensitivity to radiation. The ratio between the concentrations of the individual photoinitiators is so adjusted that the composition has virtually the same optical density for the radiation of the different emission lines at which the photoinitiators are effective.
摘要:
This invention relates to novel reactive amino or hydrazino peroxides (hereinafter generally referred to as "AHP's") and derivatives all having a Structure A: ##STR1## in which the definitions of P, R11, R22, X, Q and x, y and z are given in the Summary Of The Invention section, for example, 4,4-di-(t-butylperoxy)pentanohydrazide (I-1), and the use of these novel compounds in curing unsaturated polyester resins, in initiating polymerization of ethylenically unsaturated monomers, for modifying rheology, for crosslinking and curing olefin polymers and elastomers, for producing novel graft and block copolymers, and for producing novel polymers with covalently bound performance additive functions.
摘要:
An initiator suspension for use in the suspension polymerization of ethylenically unsaturated monomers is prepared by (a) heating the initiator to its melting point; (b) finely dividing the initiator in water while it is in a molten state; and (c) rapidly cooling so that the initiator is in a molten state for a period of time which is less than about 5 minutes. The initiator suspension has very small particles and a narrow particle size distribution whereby at least 50% by weight of the particles are smaller than 5 .mu.m and at least 90% by weight of the particles are smaller than 10 .mu.m.
摘要:
A method for preparing a tetrafluoroethylene/hexafluoropropylene copolymer by polymerizing tetrafluoroethylene and hexafluoropropylene in an aqueous medium using a di(fluoroacyl) peroxide as a polymerization initiator characterized in that a fluoroalkylcarboxylic acid is added gives a stable molecular weight of the tetrafluoroethylene/hexafluoropropylene copolymer and an increased utilization efficiency of the polymerization initiator.
摘要:
A process for the production of particulate expandable styrene polymers which have a very low benzene concentration is described using perketal and/or monoperoxycarbonate polymerization initiators. The styrene polymers produced according to the invention can be foamed to give foamed particles and molded, if desired.
摘要:
Copolymers of monoalkyl maleates or maleic acid and salts thereof and vinyl alkyl ethers are prepared by free radical copolymerization of maleic anhydride and vinyl alkyl ethers and subsequent reaction with an alkanol or water and optionally metal hydroxides and/or oxides in a process wherein at every stage of the polymerization the vinyl alkyl ether component is present in excess in the reaction mixture, the free radical copolymerization is carried out in acetone and the acetone is removed by distillation during or after the esterification or hydrolysis, which comprises using a peroxyester of a carboxylic acid of 8 or more carbon atoms as polymerization initiator. The copolymers obtained are used in cosmetic preparations.
摘要:
Water-soluble copolymers of maleic acid useful as water treatment agents are prepared by copolymerizing(a) from 99 to 80% by weight of maleic anhydride and(b) from 1 to 20% by weight of a monoethylenically unsaturated monomer copolymerizable therewith and, facultatively,(c) up to 10% by weight of a crosslinker, at from 60.degree. to 200.degree. C. in an aromatic hydrocarbon in the presence of peroxyesters derived from saturated or monoethylenically unsaturated carboxylic acids, and hydrolyzing the anhydride groups of the copolymers following the polymerization.
摘要:
This invention relates to novel reactive amino or hydrazino peroxides (hereinafter generally referred to as "AHP's") and derivatives all having a Structure A:(P--R11--X--(--NH--).sub.x --R22--).sub.y --Q].sub.z Ain which the definitions of P, R11, R22, X, Q and x, y and z are given in the Summary of The Invention section, for example, 4,4-di-(t-butylperoxy)pentanohydrazide (I-1), and the use of these novel compounds in curing unsaturated polyester resins, in initiating polymerization of ethylenically unsaturated monomers, for modifying rheology, for crosslinking and curing olefin polymers and elastomers, for producing novel graft and block copolymers, and for producing novel polymers with covalently bound performance additive functions.
摘要:
Compounds which contain peroxide linkages and the radical of a hindered amine light stabilizer group are provided. These compounds function as polymerization initiators which cause the hindered amine stabilizer to be chemically bound to the polymer.
摘要:
In curing dental resins, polymerizable compounds having at least one ethylenically unsaturated double bond, such as mono- or poly-functional acrylates or methacrylates are polymerized in the presence of N-cyclohexy-5-ethylpyrimidinetrione, a specific organometallic compound typically including acetylacetone copper or lithium acetate, and an organohalogen compound. The amounts of the ethylpyrimidinetrione, organometallic and organohalogen compounds used are respectively 0.1 to 10 parts by weight, 0.001 to 0.2 parts by weight and 0.1 to 5 parts by weight with respect to the polymerization compounds.