摘要:
A process for the preparation of a copolymer in semicontinuous operation in a polymerization apparatus including a polymerization reactor connected to a metering device, acid monomer being initially taken in the metering device and polyether macromonomer and water in the polymerization reactor, acid monomer being metered from the metering device via an acid monomer metering line into the polymerization reactor, a portion of the copolymer-containing aqueous medium being passed continuously during the free radical polymerization from the polymerization reactor via a reaction mixture line which is connected via a mixing device to the acid monomer metering line, the discharged copolymer-containing aqueous medium being mixed with the acid monomer in the mixing device during the metering of the acid monomer and being recycled to the polymerization reactor after the mixing via the acid monomer metering line.
摘要:
The present invention relates to a process for the preparation of a copolymer in semicontinuous operation in a polymerization apparatus, comprising a polymerization reactor connected to a metering device, in each case acid monomer being initially taken in the metering device and polyether macromonomer and water in the polymerization reactor, acid monomer being metered from the metering device via an acid monomer metering line into the polymerization reactor, free radical polymerization initiator being passed into the polymerization reactor before and/or during the metering of the acid monomer into the polymerization reactor so that an aqueous medium in which acid monomer and polyether macromonomer are reacted with formation of the copolymer by free radical polymerization forms in the polymerization reactor, a portion of the copolymer-containing aqueous medium being passed continuously during the free radical polymerization from the polymerization reactor via a reaction mixture line which is connected via a mixing device to the acid monomer metering line, the discharged copolymer-containing aqueous medium being mixed with the acid monomer in the mixing device during the metering of the acid monomer and being recycled to the polymerization reactor after the mixing via the acid monomer metering line.
摘要:
A process for the preparation of a copolymer in a semicontinuous mode of operation in a polymerization apparatus containing a polymerization reactor connected to a metering device, in each case acid monomer being initially introduced into the metering device and polyether macromonomer and water into the polymerization reactor, acid monomer being metered from the metering device into the polymerization reactor, the metering of the acid monomer into the polymerization reactor being effected in such a way that first a polymerization pH is established in the aqueous medium and then, until the conversion of 70 mol % of the polyether macromonomer initially introduced into the polymerization reactor, acid monomer is passed into the polymerization reactor in an amount per unit time such that the pH in the aqueous medium deviates by not more than ±0.3 from the initially established polymerization pH.
摘要:
The invention relates to a copolymer comprising i) 3 to 40 mol % of an isoprenolpolyether derivative structural unit α ii) 3 to 40 mol % of a vinyloxypolyether derivative structural unit β and iii) 35 to 93 mol % of an acid structural unit γ, the structural units of the copolymer which belong to the vinyloxypolyether derivative structural unit β having longer side chains than the structural units which belong to the isoprenolpolyether derivative structural unit α.
摘要:
The present invention concerns a cement additive containing copolymers comprising one or more constitutional units represented by formula A: (A) R1 is hydrogen, an alkyl group having 1 to 4 carbon atoms, an alkenyl group having 1 to 4 carbon atoms or an aryl group having 6 to 9 carbon atoms; R2 is hydrogen or an alkyl group having 1 to 9 carbon atoms, an alkenyl group having 1 to 9 carbon atoms or an aryl group having 6 to 9 carbon atoms; T is alkylene (including straight-chain and branched alkylene) having 1 to 4 carbon atoms or arylene having 6 to 9 carbon atoms; n is 0 or 1; S1 and S2 are, independently of one another, —OCkH2k— or —OCH2CHR3—, with the proviso that k is 2 or 3, R3 is an alkyl group having 1 to 9 carbon atoms, an aryl group having 6 to 9 carbon atoms; and 6
摘要翻译:本发明涉及包含一种或多种由式A表示的结构单元的共聚物的水泥添加剂:(A)R 1是氢,具有1至4个碳原子的烷基,具有1个 至4个碳原子或具有6至9个碳原子的芳基; R2是氢或碳原子数1〜9的烷基,碳原子数1〜9的烯基或碳原子数6〜9的芳基。 T是具有1至4个碳原子的亚烷基(包括直链和支链亚烷基)或具有6至9个碳原子的亚芳基; n为0或1; S 1和S 2 2彼此独立地是-OC 2 k H 2 - 或-OCH 3, 其中k为2或3,R3为碳原子数1〜9的烷基,碳原子数为6〜9的芳基。 和6 <_M sub> 1 + m 2 <_ 25。
摘要:
The invention relates to a polymer composition containing 3 to 90% by weight of a copolymer H and 3 to 90% by weight of a copolymer K, the copolymers H and K each having polyether macromonomer structural units and acid monomer structural units, which are present in the copolymers H and K in each case in a molar ratio of 1:20 to 1:1, and at least 20 mol % of all structural units of the copolymer H and at least 25 mol % of all structural units of the copolymer K being present in each case in the form of acid monomer structural units, at least 60 mol % of the polyether macromonomer structural units of the copolymer H being represented by the isoprenol polyether derivative structural units and at least 60 mol % of the polyether macromonomer structural units of the copolymer K being represented by the vinyloxy polyether derivative structural units.
摘要:
Copolymers based on unsaturated mono- or dicarboxylic acid derivatives, oxyalkylene glycol alkenyl ethers and optionally vinylic polyalkylene glycol or ester compounds are described and also their use as additives for aqueous suspensions based on mineral or bituminous binders, in particular cement, gypsum, lime, anhydrite, or other calcium sulphate-based binders, and based on pulverulent dispersion binders. The copolymers according to the invention impart to the aqueous binder suspensions a very good dispersing and liquefying action with, at the same time, simultaneous excellent processing properties. Moreover, the oxyalkylene glycol alkenyl ethers according to the invention are industrially relatively simple and inexpensive to prepare and need comparatively low initiator concentrations in the copolymerization.
摘要:
The invention relates to a polymer composition containing 5 to 95% by weight of a copolymer H and 2 to 60% by weight of a copolymer K, the copolymers H and K each having polyether macromonomer structural units and acid monomer structural units, which are present in the copolymers H and K in each case in a molar ratio of 1:20 to 1:1, and at least 20 mol % of all structural units of the copolymer H and at least 25 mol % of all structural units of the copolymer K being present in each case in the form of acid monomer structural units, the polyether macromonomer structural units of the copolymer H having side chains containing in each case at least 5 ether oxygen atoms, the number of ether oxygen atoms per side chain of the polyether macromonomer structural units of the copolymer H varying in such a way that the corresponding frequency distribution diagram, in which the number of ether oxygen atoms per side chain of a polyether macromonomer structural unit is plotted along the abscissa and the associated frequency for the copolymer H is plotted along the ordinate, contains at least 2 maxima.
摘要:
The invention relates to a polymer composition containing 3 to 95% by weight of a copolymer H and 3 to 95% by weight of a copolymer K, the copolymers H and K each having polyether macromonomer structural units and acid monomer structural units, which are present in the copolymers H and K in each case in a molar ratio of 1:20 to 1:1, and at least 20 mol % of all structural units of the copolymer H and at least 25 mol % of all structural units of the copolymer K being present in each case in the form of acid monomer structural units, the polyether macromonomer structural units of the copolymers H and K having side chains containing in each case at least 5 ether oxygen atoms, the number of ether oxygen atoms per side chain of the polyether macromonomer structural units of the copolymers H and K varying in each case in such a way that the corresponding frequency distribution diagrams, in which the number of ether oxygen atoms per side chain of a polyether macromonomer structural unit is plotted in each case along the abscissae and the respectively associated frequencies for the copolymers H or K are plotted in each case along the ordinates, contain in each case at least 2 maxima whose abscissa values differ in each case by more than 7 ether oxygen atoms from one another, the frequency distribution diagrams of the copolymers H and K differing from one another in that the abscissa value of at least one maximum of the copolymer H differs in each case by more than 5 ether oxygen atoms from the abscissa values of all maxima of the copolymer K and/or that the arithmetic means of the ether oxygen atoms of the polyether macromonomer structural units of the copolymers H and K differ from one another by more than 5 ether oxygen atoms.
摘要:
The invention relates to a copolymer which is suitable as a superplasticizer for hydraulic binders and comprises 5 to 55 mol % of an isoprenol polyether derivative structural unit, 2 to 90 mol % of an acrylic acid derivative structural unit and 2 to 90 mol % of a hydroxyalkyl acrylate structural unit.