71.
    发明专利
    未知

    公开(公告)号:MXPA01005256A

    公开(公告)日:2001-09-01

    申请号:MXPA01005256

    申请日:2001-05-25

    Applicant: BASF AG

    Abstract: The invention relates to hydrogels capable of absorbing aqueous fluids, which hydrogels are produced by polymerization of olefinically unsaturated carboxylic acids or their derivatives. The hydrogels are characterized in that before, during or after the polymerization reaction and before drying a silicic acid alkali salt of the general formula (I) M2O×nSiO2 is added to the polymerization reaction mixture. In said formula M is an alkali metal and n is a number between 0.5 and 4. The hydrogel obtained in this way is then dried at an elevated temperature. The invention also relates to a method for producing said hydrogels and to their use for absorbing aqueous fluids.

    METHOD FOR CROSS-LINKING HYDROGELS WITH BIS- AND POLY-2-OXAZOLIDINONES

    公开(公告)号:CA2319453A1

    公开(公告)日:1999-09-02

    申请号:CA2319453

    申请日:1999-02-24

    Applicant: BASF AG

    Abstract: The invention relates to a method for surface subsequent cross-linking of water absorbing polymers. The invention is characterized in that the polymers are treated with a surface subsequent cross-linking solution and are subsequently cross-linked and dried during or after treatment by increasing the temperature. The invention is additionally characterized in that the crosslinking agent contains a bis-2-oxazolidinone or a poly-2-oxazolidinone which is dissolved in an inert solvent and which comprises structural units of general formula (I), wherein R1 is a branched or unbranched C1-C18-alkylene, a branched or unbranched C2-C18-alkenylene, C5-C8-cycloalkylene, phenylene, naphthylene, anthracenylene, phenylene substituted with hydrocarbons, naphthylene or anthracenylene or another substituted or non-substituted C6-C18-arylene radical; R2 is a branched or unbranched C1-C18-alkylene, and; n is a whole number from 1 to 50. In addition, the cross-linking agent can also contain a mixture of bis-2-oxazolidinones and poly-2-oxazolidinones dissolved in an inert solvent.

    Method for production of water-absorbing polymers

    公开(公告)号:ZA200709067B

    公开(公告)日:2010-01-27

    申请号:ZA200709067

    申请日:2007-10-22

    Applicant: BASF AG

    Abstract: Preparation of water-absorbing polymers (A) with drying quality index comprises polymerizing a monomer solution and drying the obtained hydrogel agent in hot-gas flow, where the drying process takes place in at least two temperature zones, when the flow of the hydrogel in the gas flow is: downwards in the front side of the volume drier, and upwards against the rear side of the drier; where the amount of water in the hydrogel is 15-45 wt.%, the hydrogel layer in the volume drier flows at least partially against down wards, and the speed of the gas is 5-30%. Preparation of water-absorbing polymers (A) with drying quality index comprises polymerizing a monomer solution and drying the obtained hydrogel agent in hot-gas flow, where the drying process takes place in at least two temperature zones, when the gas inlet temperature (T n) is not equal to T n + a; and flow of the hydrogel in the gas flow is: downwards in the front side of the volume drier, and upwards against the rear side of the drier; where the amount of water in the hydrogel is 15-45 wt.%, the hydrogel layer in the volume drier flows at least partially against down wards, and the speed of the gas is 5-30%. n : index; and a : greater than 0. An independent claim is included for a device for drying (A) comprising a gas permeable conveyer belt (which is streamed by a preheated gas), where the gas inlet temperature is adjusted such that it can come form at least two temperature zones.

    76.
    发明专利
    未知

    公开(公告)号:BRPI0507793A

    公开(公告)日:2007-07-17

    申请号:BRPI0507793

    申请日:2005-02-18

    Applicant: BASF AG

    Abstract: The invention concerns a process for producing water-absorbing polymer, which comprises a base polymer A being mixed with a first aqueous solution B of at least one surface postcrosslinker and a second aqueous solution C of at least one polyvalent cation and thermally treated, wherein said base polymer A is based on at least 50% neutralized acid-functional monomer and said solutions B and C are metered wholly or partly concurrently through separate nozzles whereby a water-absorbing polymer having a high saline flow conductivity value is obtained.

    Preparation of water-absorbing resin, useful in sanitary articles e.g. diapers, comprises polymerizing a reaction mixture comprising hydrophilic monomer and cross-linker

    公开(公告)号:DE102005062929A1

    公开(公告)日:2007-07-05

    申请号:DE102005062929

    申请日:2005-12-29

    Applicant: BASF AG

    Abstract: Preparation of water-absorbing resin by polymerization of a reaction mixture comprising at least one hydrophilic monomer and optionally at least one cross-linker, comprises mixing at least a first portion of a particulate additive in the reaction mixture, before the reaction mixture reaches a retention time of 40% of the total retention time in the reactor; and mixing at least a second portion of a particulate additive in the reaction mixture, when the reaction mixture reaches a retention time of 45% or more of the total retention time in the reactor. Preparation of water-absorbing resin by polymerization of a reaction mixture comprising at least one hydrophilic monomer and optionally at least one cross-linker, in a reactor, comprises mixing at least a first portion of a particulate additive in the reaction mixture, before the reaction mixture reaches a retention time of 40% of the total retention time in the reactor; and mixing at least a second portion of a particulate additive in the reaction mixture, when the reaction mixture reaches a retention time of 45% or more of the total retention time in the reactor, where: the additive is a water-adsorbing resin powder and/or filler; the total solid content of the monomer and additive is 30-60 wt.%; the amount of the additive is 5-50 wt.%, based on the monomer; and the weight ratio of the first fraction to the second fraction of the additive is 10:10-1:5.

    80.
    发明专利
    未知

    公开(公告)号:DE102005042607A1

    公开(公告)日:2007-03-08

    申请号:DE102005042607

    申请日:2005-09-07

    Applicant: BASF AG

    Abstract: The invention relates to a process for preparing water-absorbing polymer particles, comprising the inertization of monomer solutions, wherein the monomer solution, based on the dissolved monomer, comprises from 0.001 to 0.016% by weight of at least one polymerization inhibitor and at least 50% by volume of the inert gas used to inertize the monomer solution is transferred into the polymerization reactor together with the inertized monomer solution, and also to apparatus for performing the process.

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