Basf Se Corporation

Bostik, Inc.

Christophe Bauduin

Thomas Daniel

Katrin Baumann

Norbert Herfert

Stephan Bauer

Markus Toennessen

Katarzyna Dobrosielska-Oura

Rolf Pinkos

Michael A Mitchell

Jürgen Freiberg

Wolfgang Fischer

Thomas Krug

Thomas Pfeiffer

Birgit Reinhard

Marco Krüger

Andreas Daiss

Tilman Sirch

Gerd-Dieter Tebben

Markus Christian Biel

Axel Paul

Daniel Breuninger

Jean-Francois Chartrel

Edzard Scholten

Jörg Belack

Gerhard Fritz

Maria Guixa Guardia

Asif Karim

Yvonne Hagen

Juergen Freiberg

Renate Wuestefeld

Markus Muehl

Hans Wagner

Marc Haefner

Karsten Kraemer

Julien Liger

Joerg Belack

Michael Mitchell

Michael Mitchel

A highly permeable superabsorbent is prepared by a process comprising polymerizing an aqueous monomer solution comprising a) at least one ethylenically unsaturated monomer which bears acid groups and is optionally at least partly in salt form, b) at least one crosslinker, c) at least one initiator, d) optionally one or more ethylenically unsaturated monomers copolymerizable with the monomers mentioned under a), and e) optionally one or more water-soluble polymers; drying the resulting polymer, optionally grinding the dried polymer and sieving the ground polymer, optionally surface postcrosslinking the dried and optionally ground and sieved polymer, adding x-ray-amorphous aluminum hydroxide powder after drying, grinding or sieving, and, if surface postcrosslinking is conducted, during or after this surface postcrosslinking, adding 0.1% to 10% by weight, based on the amount of polymer prior to the addition of the x-ray-amorphous aluminum hydroxide powder, of water after the addition of x-ray-amorphous aluminum hydroxide powder, wherein the water is added to the superabsorbent in at least three portions.

Permeable superabsorbent and process for production thereof

A method of measuring indices in superabsorbents, by initially charging excess aqueous solution or dispersion, swelling the superabsorbent in the initially charged aqueous solution or dispersion while stirring, dissolving or dispersing a component A in the aqueous solution or dispersion, measuring the enrichment of component A in the aqueous solution or dispersion during the swelling of the superabsorbent, using the enrichment of component A in the aqueous solution or dispersion to measure the time-dependent swelling characteristics and using these to determine the swelling constant k or the characteristic swell time τ, the index being dependent on the permeability of the superabsorbent, and ascertaining the index by means of a correlation measured beforehand between swelling constant k and index or characteristic swell time τ and index.

Method for measuring the permeability of superabsorbers

A fluid-absorbent article includes an upper liquid-pervious layer (A), a lower liquid-impervious layer (B), a fluid-absorbent core (C) between (A) and (B) including at least 60% by weight of non-surface postcrosslinked fluid-absorbent polymer particles and not more than 40% by weight of fibrous material, based on the sum of non-surface postcrosslinked fluid-absorbent polymer particles and fibrous material. An acquisition-distribution layer (D) between (A) and (C) includes at least 90% by weight of synthetic fibers and not more than 10% by weight of cellulose based fibers, based on the sum of synthetic fibers and cellulose based fibers. The basis weight of the acquisition-distribution layer (D) is at least 70 gsm. The fluid-absorbent polymer particles have a saline flow conductivity (SFC) of less than 5×10cms/g and an AUHL of less than 15 g/g. Preferably the acquisition-distribution layer (D) is a non-woven web including a three dimensional network of fibers.

Fluid-absorbent article

A highly permeable superabsorbent is prepared by a process comprising polymerizing an aqueous monomer solution comprising

Provided herein are fluid-absorbent articles, fluid absorbent cores, and fluid-absorbent mixtures with improved properties, especially rewet performance and liquid acquisition. The fluid-absorbent article includes (A) an upper liquid-pervious sheet, (B) a lower liquid-impervious sheet, (C) a fluid-absorbent core including from 60 to 20% by weight fibrous material and from 40 to 80% by weight of at least a first type of water-absorbent polymer particles, (G) and at least a second type of water-absorbent polymer particles (H) based on the sum of water-absorbent polymer particles and fibrous material, (D) an optional acquisition-distribution layer (D) between (A) and (C), (F) other optional components, wherein the first type of water absorbent polymer particles (G) of the fluid-absorbent core (C) have a SFC of at least 20×10cm·s/g, and wherein the at least second type of water-absorbent polymer particles (H) of the fluid-absorbent core have a sphericity of at least 0.80.

In a method of measuring parameters of superabsorbents, the absorption capacity of superabsorbents is determined under pressure, by reducing the pressure applied to a sample of the superabsorbent stepwise and determining the absorption capacity at each pressure. In addition, the rise in absorption capacity after a reduction in pressure is measured as a function of time and this is used to calculate the swelling constant k or the characteristic swelling time τ. Swelling constant or characteristic swelling time or the magnitude of the difference in absorption capacity at two different pressures are used to determine further parameters of the superabsorbent.

Method for determining characteristics of super-absorbents

Superabsorbent mixtures M comprising at least 70% by weight of superabsorbent A having a liquid absorption of 20 g/g (T20) of less than 300 s and/or a volumetric liquid absorption under pressure 0.3 psi (2.07 kPa) (VAUL) with a &#x3c4; value of less than 400 s, and at least 5% by weight of superabsorbent B having a centrifuge retention capacity (CRC) of at least 30 g/g.

Superabsorber mixtures

An apparatus for production of pulverulent polymers having a reactor for droplet polymerization with an apparatus for dropletization of a monomer solution for the preparation of the polymer. The apparatus for dropletization has holes through which the monomer solution is introduced, an addition point for a gas above the apparatus for dropletization, at least one gas withdrawal point at the periphery of the reactor and a fluidized bed, wherein at least one of the following is fulfilled:

Device and method for producing powdered polymers

The present invention relates to a process for producing surface-postcrosslinked water-absorbent polymer particles by coating of water-absorbent polymer particles having a content of residual monomers in the range from 0.03 to 15% by weight with at least one surface-postcrosslinker and thermal surface-postcrosslinking at temperatures in the range from 100 to 180&#xb0; C.

Process for producing surface-postcrosslinked water-absorbent polymer particles

The present invention relates to a process for producing water-absorbing polymer particles having an improved profile of properties, comprising thermal surface postcrosslinking in the presence of a salt of a polyvalent metal cation and a complexing anion and subsequent aftertreatment, the aftertreatment comprising coating with a salt of a polyvalent metal cation and a non-complexing anion, and remoisturization with further drying.

Method for producing water-absorbent polymer particles with improved properties

The present invention relates to improved water-absorbing storage layers for use in hygiene articles, the water-absorbing storage layers being essentially free of cellulose fibers.

Water absorbent storage layers

The present invention is directed to a liquid-absorbing article comprising:

Absorbent article and process for making it

A process for producing thermally surface postcrosslinked water-absorbing polymer particles, wherein the water-absorbing polymer particles are coated before, during or after the thermal surface postcrosslinking with at least one complex consisting of a polyvalent metal salt and a 2-hydroxycarboxamide.

Process for producing thermally surface postcrosslinked water-absorbing polymer particles

A process for producing water-absorbing polymer particles with low caking tendency and high absorption under pressure, comprising polymerization of a monomer solution or suspension, drying of the resulting polymer gel, grinding, classifying, thermal surface postcrosslinking and coating with silicon dioxide, wherein the water-absorbing polymer particles have been coated, before, during or after the surface postcrosslinking with aluminum cations.

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Plankstadt, Germany

Christophe Bauduin