Basf Se Corporation

Markus Braun

Matthias Weismantel

Ulrich Riegel

Rainer Dyllick-Brenzinger

Michael A Mitchell

Arnold Schneller

Thomas Gieger

Kathrin Michl

Stephan Deuerlein

Monica Haag

Michael Kalbe

Martin Wendker

Volker Klock

Christian Krueger

Roland Krauss

Evgueni Klimov

Francesca Aulenta

Michael Mitchell

Christian KRÜGER

Francessa Aulenta

A process for producing water-absorbing polymer particles is provided, comprising a) a polymerization step in which an aqueous monomer solution comprising at least one ethylenically unsaturated monomer M which bears acid groups and may have been at least partly neutralized and at least one crosslinker is polymerized to obtain an aqueous polymer gel; b) a pelletization step in which the aqueous polymer gel having a solids content of 35 to 70% by weight and a temperature of 75 to 125&#xb0; C. is forced from a high-pressure zone through a die plate into a low-pressure zone and pellets are obtained, the pressure differential between the high-pressure zone and the low-pressure zone being 4 to less than 14 bar and the orifice ratio of the die plate being 30 to 80%; c) a drying step in which the pellets are dried to a moisture content of less than 10% by weight; d) a grinding step and a classifying step to obtain water-absorbing polymer particles; and e) surface crosslinking of the water-absorbing polymer particles. The water-absorbing polymer particles have a high swell rate and a high retention capacity combined with a favorable ratio of permeability of the swollen gel bed SFC to centrifuge retention capacity CRC.

Method for producing water-absorbing polymer particles

A process for producing water-absorbing polymer particles with high free swell rate by polymerizing a monomer solution or suspension comprising an ethylenically unsaturated monomer bearing acid groups, a crosslinker, an initiator and an ethylenically unsaturated ionic surfactant.

Process for producing water-absorbing polymer particles with high free swell rate

Crosslinked polymer particles having a) a proportion of particles having a particle size of 150 to 300 &#x3bc;m of at least 20% by weight, b) a free swell rate of the entirety of the polymer particles FSRof at least 0.25 g/g&#xb7;s, c) a difference &#x394;FSR of at least 0.15, d) a centrifuge retention capacity CRC of at least 25.0 g/g, and e) a permeability of the swollen gel bed SFC of at least 90&#xd7;10cm&#xb7;s/g are disclosed.

Water-absorbing polymer particles

A process for producing water-absorbing polymer particles with high free swell rate and high permeability by polymerization of an aqueous monomer solution or suspension to give an aqueous polymer gel, wherein a thermal blowing agent essentially free of inorganic acid anions is mixed into the polymer gel, and subsequent thermal drying of the polymer gel.

Water-absorbing polymer particles with high free swell rate and high permeability

Aqueous binders for granular and/or fibrous substrates are based on polyacids and polyols.

Aqueous binder for granular and/or fibrous substrates

Aqueous binders for granular and/or fibrous substrates comprising as active constituents: a) at least one polymer which is obtainable by free-radical addition polymerization and comprises in copolymerized form &#x2267;5.5% and &#x2267;20% by weight of an &#x3b1;,&#x3b2;-ethylenically unsaturated monocarboxylic or dicarboxylic acid [polymer A], b) at least one polymer which is obtainable by free-radical addition polymerization and comprises in copolymerized form &#x2267;40% by weight of an &#x3b1;,&#x3b2;-ethylenically unsaturated monocarboxylic or dicarboxylic acid [polymer B], and c) at least one polyol compound having at least two hydroxyl groups [polyol C].

Aqueous binders granulated and/or fibrous substrates

Aqueous binder for granular and/or fibrous substrates based on polyacids, polyols and basic nitrogen compounds.

Aqueous binders for granular and/or fibrous substrates

The invention relates to a process for producing water-absorbing polymer particles with improved permeability, comprising the steps of polymerization, drying, grinding, classification and thermal surface postcrosslinking, with pneumatic conveying between grinding and classification.

Process for producing water-absorbing polymer particles with improved permeability

A process for producing water-absorbing polymer particles by polymerizing an aqueous monomer solution in a kneader having at least two shafts in axially parallel rotation, wherein the reaction mixture is transported in axial direction and the region at the start of the kneader is trace-heated.

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Heidelberg, Germany

Markus Braun