摘要:
A polymer mixture in solid or aqueous form includes a content of from 5 to 95% by weight of a first polymer and a content of from 5 to 95% by weight of a second polymer. The first polymer is a water-soluble or water-dispersible polymer having a weight-average molecular weight of 1000 to 20 000 g/mol. The second polymer is a water-soluble or water-dispersible polymer having a weight-average molecular weight of 1000 to 50 000 g/mol. The polymer mixture can inhibit precipitation and sedimentation of calcium salts and magnesium salts in water-bearing systems.
摘要:
A polymer mixture in solid or aqueous form includes a content of from 5 to 95% by weight of a first polymer and a content of from 5 to 95% by weight of a second polymer. The first polymer is a water-soluble or water-dispersible polymer having a weight-average molecular weight of 1000 to 20 000 g/mol. The second polymer is a water-soluble or water-dispersible polymer having a weight-average molecular weight of 1000 to 50 000 g/mol. The polymer mixture can inhibit precipitation and sedimentation of calcium salts and magnesium salts in water-bearing systems.
摘要:
The invention relates to copolymers which comprise, in copolymerized form, a1) 30 to 90% by weight of at least one monoethylenically unsaturated C3-C8-carboxylic acid or of an anhydride or salt thereof, a2) 3 to 60% by weight of at least one monomer comprising sulfo groups, a3) 3 to 60% by weight of at least one nonionic monomer of the formula I H2C═C(R1)(CH2)xO[R2—O]0—R3 (I) in which R1 is hydrogen or methyl, R2 are identical or different, linear or branched C2-C6-alkylene radicals which may be arranged in blocks or randomly, and R3 is hydrogen or a straight-chain or branched C1-C4-alkyl radical, x is 0, 1 or 2 and o is a natural number from 3 to 50, a4) 0 to 30% by weight of one or more further ethylenically unsaturated monomers which are polymerizable with a1), a2) and a3), where the sum of a1), a2), a3) and a4) adds up to 100% by weight.
摘要:
The invention relates to copolymers which comprise, in copolymerized form, a1) 30 to 90% by weight of at least one monoethylenically unsaturated C3-C8-carboxylic acid or of an anhydride or water-soluble salt thereof, a2) 3 to 60% by weight of at least one monomer comprising sulfo groups, a3) 3 to 60% by weight of at least one nonionic monomer of the formula (I) H2C═C(R1)COO—[R2—O]o—R3 (I) in which R1 is hydrogen or methyl, R2 are identical or different, linear or branched C2-C6-alkylene radicals which may be arranged in blocks or randomly, and R3 is hydrogen or a straight-chain or branched C1-C4-alkyl radical and o is a natural number from 3 to 50, a4) 0 to 30% by weight of one or more further ethylenically unsaturated monomers which are polymerizable with a1), a2) and a3), where the sum of a1), a2), a3) and a4) adds up to 100% by weight.
摘要:
The invention relates to copolymers which comprise, in copolymerized form, a1) 30 to 90% by weight of at least one monoethylenically unsaturated C3-C8-carboxylic acid or of an anhydride or water-soluble salt thereof, a2) 3 to 60% by weight of at least one monomer comprising sulfo groups, a3) 3 to 60% by weight of at least one nonionic monomer of the formula (I) H2C═C(R1)COO—[R2—O]o—R3 (I) in which R1 is hydrogen or methyl, R2 are identical or different, linear or branched C2-C6-alkylene radicals which may be arranged in blocks or randomly, and R3 is hydrogen or a straight-chain or branched C1-C4-alkyl radical and o is a natural number from 3 to 50, a4) 0 to 30% by weight of one or more further ethylenically unsaturated monomers which are polymerizable with a1), a2) and a3), where the sum of a1), a2), a3) and a4) adds up to 100% by weight.
摘要:
The invention relates to an aqueous solution of acrylic acid polymers, obtainable by polymerization of acrylic acid in feed mode with peroxodisulfate as initiator in the presence of hypophosphite in water as solvent, wherein (i) water and optionally one or more ethylenically unsaturated comonomers are initially charged, and (ii) acrylic acid in acidic, unneutralized form, optionally one or more ethylenically unsaturated comonomers, aqueous peroxodisulfate solution and aqueous hypophosphite solution are added continuously, and (iii) a base is added on completion of the acrylic acid feed to the aqueous solution, wherein the comonomer content does not exceed 30% by weight, based on total monomer content.
摘要:
A process for preparing aqueous solutions of homo- or copolymers of acrylic acid by means of free-radical polymerization of acrylic acid and optionally water-soluble, monoethylenically unsaturated comonomers in an aqueous medium in the presence of at least one water-soluble initiator and of at least one water-soluble regulator, wherein the polymerization is conducted by means of a continuous process, and wherein, after the polymerization, low molecular weight components are at least partly removed from the resulting aqueous polymer solution. For the polymerization, preference is given to using microstructured mixers and reactors. Preference is given to using at least one reactor and/or mixer with microstructures for the process.
摘要:
A process for preparing aqueous solutions of homo- or copolymers of acrylic acid by means of free-radical polymerization of acrylic acid and optionally water-soluble, monoethylenically unsaturated comonomers in an aqueous medium in the presence of at least one water-soluble initiator and of at least one water-soluble regulator, wherein the polymerization is conducted by means of a continuous process, and wherein, after the polymerization, low molecular weight components are at least partly removed from the resulting aqueous polymer solution. For the polymerization, preference is given to using microstructured mixers and reactors. Preference is given to using at least one reactor and/or mixer with microstructures for the process.
摘要:
Aqueous solutions of acrylic acid polymers are prepared by polymerization of acrylic acid in a feed operation with a free-radical initiator in the presence of hypophosphite in water as solvent, by a process comprising (i) initially charging water and optionally one or more ethylenically unsaturated comonomers, (ii) continuously adding acrylic acid in acidic, unneutralized form, optionally one or more ethylenically unsaturated comonomers, aqueous free-radical initiator solution and aqueous hypophosphite solution, and (iii) adding a base to the aqueous solution on completion of the acrylic acid feed, wherein a comonomer content does not exceed 30% by weight and the aqueous hypophosphite solution is added during a total feed time made up of three consecutive feed time spans ΔtI, ΔtII, and ΔtIII, wherein the average feed rate in the second feed time span ΔtII is greater than the average feed rates in the first and third feed time spans ΔtI and ΔtIII.
摘要:
The present invention relates to a method for the continuous production of a polymer by radical polymerization, wherein at least three materials are mixed with microstructures in one or more mixers and are then polymerized in at least one reaction zone.