摘要:
The invention relates to a method for producing sodium dithionite comprising the steps (a) production of a synthesis batch consisting of sodium formate, sulphur dioxide and an alkaline sodium compound in an aqueous methanol solvent, which forms a sodium dithionite mother liquor, (b) separation of the sodium dithionite from the sodium dithionite mother liquor, leaving a residual mother liquor, (c) separation of methanol from the residual mother liquor, (d) separation of the residual mother liquor into a first sub-stream that is rich in thiosulphate and a second sub-stream that is devoid of thiosulphate, but contains formate by means of a nanofiltration, (e) concentration of sodium formate in the second sub-stream and (f) return of the concentrated second sub-stream to step (a).
摘要:
The invention concerns agglomerated polymer particles made from water-expandable polymers and with a mean particle diameter of 20-5000 νm. The agglomerated polymer particles consist of primary particles with a mean particle diameter of 0.1-15 νm and can be produced by polymerisation of water-soluble monomers in the presence of a regulator (1-10 wt % in relation to the monomers) and of a cross linking agent (at least 2000 ppm in relation to the monomers), the process being a water-in-oil polymerisation, with subsequent azeotropic de-watering of the water-in-oil polymer emulsion containing the primary particles in the presence of agglomerating polyalkylene glycols which (a) can be obtained by addition fixation of C2-C4 alkylene oxides to alcohols, phenols, amines or carboxylic acids and (b) contain at least two alkylene oxide units incorporated by polymerisation. The agglomerated polymer particles break down into the primary particles when introduced into water. The invention also concerns processes for producing the agglomerated polymer particles and the use of said particles as thickening agents for printing pastes.
摘要:
Disclosed is calcium carbonate with a high degree of brightness, which is produced by treating calcium carbonate, and/or the milk of lime used for the production thereof by reacting milk of lime with carbon dioxide, and/or at least one of the calcium-containing intermediate products used for the production of milk of lime, with a bleaching agent before, during, and/or following said reaction. Said bleaching agent contains at least one compound of formula A[(CR1R2)SOpM(1/q)]r (I), in which A represents NR3R4, NR3, N, or OH; R1, R2, R3, R4 independently represent hydrogen or an organic radical; M represents ammonium or a metal; p represents 2 or 3; q represents the valence of M; and r represents 1 if A=OH or NR3R4, 2 if A=NR3, and 3 if A=N. Said variables are independently selected for each individual compound and/or each [(CR1R2)SOpM(1/q)] group if a mixture of compounds is used and/or if r=2 or 3.
摘要:
The invention concerns agglomerated particles of finely divided polymers which are water-soluble or capable of swelling in water and contain ammonium carboxlyate groups, and a process for their preparation by azeotropic dehydration of water-in-oil emulsions of the polymers, which are water-soluble or capable of swelling in water and contain ammonium carboxylate groups, in the presence of 0.1 to 40 wt %, relative to the polymers, of polyalkylene glycols, which have an agglomerating effect and are obtained by the addition of C2 to C4 alkylene oxides to alcohols, phenols, amines or carboxylic acids and which contain at least two alkylene oxide units incorporated by polymerization, and additionally from 0.1 to 20 wt %, relative to the polymers, of protective colloids which are obtained by radical copolymerization of C8 to C40 mono-olefins with monoethylenically unsaturated C4 to C6 dicarboxylic acid anhydrides in the manner of a substance polymerization at temperatures from 80 to 300 °C to form copolymers having molar masses of 500 to 20,000 g/mol. The invention further concerns the use of the agglomerated polymer particles as thickeners for textile pigment printing inks.
摘要:
The invention relates to a method for reducing the quantity of residual monomers in aqueous polymerisate dispersions by post-treating them with a redox initiator system.
摘要:
The invention concerns agglomerated polymer particles made from water-expandable polymers and with a mean particle diameter of 20-5000 νm. The agglomerated polymer particles consist of primary particles with a mean particle diameter of 0.1-15 νm and can be produced by polymerisation of water-soluble monomers in the presence of a regulator (1-10 wt % in relation to the monomers) and of a cross linking agent (at least 2000 ppm in relation to the monomers), the process being a water-in-oil polymerisation, with subsequent azeotropic de-watering of the water-in-oil polymer emulsion containing the primary particles in the presence of agglomerating polyalkylene glycols which (a) can be obtained by addition fixation of C2-C4 alkylene oxides to alcohols, phenols, amines or carboxylic acids and (b) contain at least two alkylene oxide units incorporated by polymerisation. The agglomerated polymer particles break down into the primary particles when introduced into water. The invention also concerns processes for producing the agglomerated polymer particles and the use of said particles as thickening agents for printing pastes.
摘要:
The invention concerns agglomerated particles of finely divided polymers which are water-soluble or capable of swelling in water and contain ammonium carboxlyate groups, and a process for their preparation by azeotropic dehydration of water-in-oil emulsions of the polymers, which are water-soluble or capable of swelling in water and contain ammonium carboxylate groups, in the presence of 0.1 to 40 wt %, relative to the polymers, of polyalkylene glycols, which have an agglomerating effect and are obtained by the addition of C2 to C4 alkylene oxides to alcohols, phenols, amines or carboxylic acids and which contain at least two alkylene oxide units incorporated by polymerization, and additionally from 0.1 to 20 wt %, relative to the polymers, of protective colloids which are obtained by radical copolymerization of C8 to C40 mono-olefins with monoethylenically unsaturated C4 to C6 dicarboxylic acid anhydrides in the manner of a substance polymerization at temperatures from 80 to 300 DEG C to form copolymers having molar masses of 500 to 20,000 g/mol. The invention further concerns the use of the agglomerated polymer particles as thickeners for textile pigment printing inks.
摘要:
A process is disclosed for preparing aqueous solutions of poly(N-vinyl- epsilon -caprolactam) by polymerising poly(N-vinyl- epsilon -caprolactam) in an aqueous medium in the presence of polymerisation initiators and 0.1 to 20 % by weight, in relation to the monomers used, of a water-soluble, polymer protective colloid. The thus obtained aqueous polymer solutions are useful as textile printing glues, raw materials for glues, lubricant additives, vehicles for cosmetic compositions, additives for washing products and as opacifiers in automatic shading systems.
摘要:
A process is disclosed for preparing aqueous solutions of poly(N-vinyl-ε-caprolactam) by polymerising poly(N-vinyl-ε-caprolactam) in an aqueous medium in the presence of polymerisation initiators and 0.1 to 20 % by weight, in relation to the monomers used, of a water-soluble, polymer protective colloid. The thus obtained aqueous polymer solutions are useful as textile printing glues, raw materials for glues, lubricant additives, vehicles for cosmetic compositions, additives for washing products and as opacifiers in automatic shading systems.