摘要:
The present invention provides a process for preparing polymer powders by evaporating the volatile constituents from aqueous dispersions of film-forming polymers P in the presence of drying assistants T selected from the salts of oligomeric arylsulfonic acid-formaldehyde condensates wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion comprises at least 1.5% by weight, preferably at least 1.7% by weight, based on the polymer in the dispersion, of at least one anionic surface-active compound AO having at least one C6-C32 alkyl group; the polymer powders obtainable by the process; and their use in binding mineral building materials.
摘要:
An aqueous polymer dispersion, wherein the dispersion contains from 0.0001 to 1 mol of a hydrolyzable silicon group and from 0.0001 to 1 mol of a urea or thiourea group, based, in each case, on 100 g of the polymer present in the dispersion.
摘要:
A readily water-redispersible and water-wettable polymer powder is prepared by spray-drying of an aqueous dispersion of polymer particles with admixing of a hydrophilic and of a hydrophobic antiblocking agent.
摘要:
Cement-based compositions comprising per 100 parts by weight of cement from 1 to 500 parts by weight of a polymer built up from a) 30-99.5% by weight of at least one alkyl ester of (meth)acrylic acid, b) 0-70% by weight of at least one vinylaromatic, c) 0.5-10% by weight of at least one alkyl polyethoxy(meth)acrylate of the formula where R1 is a hydrogen atom or a methyl group, R2 is a C1 to C4 alkyl group and n is an integer from 1 to 55, d) 0-10% by weight of at least one ethylenically unsaturated mono- or dicarboxylic acid, such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, or anhydride, amide or hydroxyalkylamide thereof, e) 0-10% by weight of acrylonitrile or methacrylonitrile, and f) 0-50% by weight of further ethylenically unsaturated compounds other than a) to e).
摘要:
Polymer dispersions comprise at least one copolymer which contains, as polymerized monomers, a) from 25 to 70% by weight of at least one conjugated aliphatic diene, b) from 25 to 70% by weight of at least one vinylaromatic monomer, c) from 2.5 to 15% by weight of at least one monoester of a C2-C10-alkanediol with acrylic acid or methacrylic acid or c′) from 0.1 to 10% by weight of at least one alkylpolyethylene glycol (meth)acrylate of the formula (I) where R1 is hydrogen or methyl, R2 is C1-C4-alkyl and n is an integer from 1 to 100, or c″) from 2 to 15% by weight of a mixture of the monoester c) and the alkylpolyethylene glycol (meth)acrylate c′), d) from 0 to 1.0% by weight of ethylenically unsaturated monomers which have at least one acid group, or salts thereof, e) from 0 to 5.0% by weight of ethylenically unsaturated nitriles and f) from 0 to 1.0% by weight of amides of &agr;,&bgr;-ethylenically unsaturated mono- and dicarboxylic acids. The polymer dispersions described are suitable, inter alia, as additives in building materials based on hydraulic binders.
摘要:
A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.
摘要:
A process for preparing a polymer powder by evaporating the volatile constituents from an aqueous dispersion of a film-forming polymer P, wherein prior to the evaporation of the volatile constituents the aqueous polymer dispersion still comprises drying assistants T, present in an amount of from 0.1 to 80% by weight, based on the polymer P of the dispersion, and there being used as drying assistant T polyvinylformamide. The polyvinylformamide used preferably has a K value (KW), determined by the method of Fikentscher in accordance with DIN 53726, of from 5 to 50.
摘要:
The present invention relates to a process for preparing polymer powders from aqueous polymer dispersions in which the dispersed polymer P comprises in copolymerized form: i) at least one vinylaromatic monomer (a), ii) 1,3-butadiene as monomer (b), and iii) one or more monomers (c) different than the monomers (a) and (b), which comprises drying the aqueous polymer dispersion in the presence of polyvinyl alcohol as drying agent. The present invention also relates to the polymer powders obtainable by this process and to the use of these polymer powders as binders in paints, varnishes and coating compositions generally, in adhesives, and for modifying mineral construction materials. The present invention also relates to mineral construction materials in the form of dry formulations comprising the polymer powders of the invention.
摘要:
The present invention relates to the use of comb polymers which have a carbon backbone which bears polyether groups of the formula A *—U—(C(O))k—X-(Alk-O)n—W A wherein * indicates the binding site to the carbon backbone of the comb polymer, U stands for a chemical bond or an alkylene group with 1 to 8 C atoms, X means oxygen or a NR group, k is 0 or 1, n stands for a whole number, the mean value whereof, based on the comb polymer, lies in the range from 5 to 300, Alk stands for C2-C4 alkylene, where Alk within the group (Alk-O)n can be the same or different, W means a hydrogen, a C1-C6 alkyl residue or an aryl residue or means the group Y-Z, Y stands for a linear or branched alkylene group with 2 to 8 C atoms, which may bear a phenyl ring, Z stands for a 5- to 10-membered nitrogen heterocycle bound via nitrogen, which can have as ring members, as well as the nitrogen atom and as well as carbon atoms, 1, 2 or 3 additional hetero atoms, selected from oxygen, nitrogen and sulfur, wherein the nitrogen ring members can contain a group R′, and wherein 1 or 2 carbon ring members can be present as carbonyl groups, R stands for hydrogen, C1-C4 alkyl or benzyl, and R′ stands for hydrogen, C1-C4 alkyl or benzyl; and functional groups B, which are present in the form of anionic groups at pH>12, and salts thereof as grinding aids in cement-containing preparations.
摘要:
A polymer is obtained by removing the medium from a polymer dispersion or polymer solution containing at least one polymeric phase and at least one stabilizer suitable to protect against the damaging effect of light, heat and/or oxidation.