Abstract: The invention relates to a process for the preparation of superabsorbent polymers based on fine-particled non-crosslinked and/or crosslinked aqueous polyacrylonitrile emulsions.
Abstract: A process is described for effectively reducing the residual monomer content of an aqueous polymer dispersion by aftertreatment at atmospheric pressure or above with an initiator system comprising a) a hydroperoxide, hydrogen peroxide or a peracid, and b) an &agr;-hydroxy carboxylic acid, such as tartaric acid, or with a salt thereof.
Type:
Grant
Filed:
March 17, 2000
Date of Patent:
September 3, 2002
Assignee:
BASF Aktiengesellschaft
Inventors:
Robert Rupaner, Gerhard Bauer, Sven Lawrenz, Claudia Heibel, Johannes Dobbelaar
Abstract: The present invention relates to a thermoplastic resin composition comprising a rubber-reinforced thermoplastic resin (A) obtained by graft polymerizing a monomeric mixture (b) comprising an aromatic vinyl compound, a vinyl cyanide compound and optionally other copolymerizable monomeric compound(s) in the presence of a rubber-like polymer (a),
Abstract: In a process for reacting an organic compound in the presence of a catalyst comprising, as active metal, at least one metal of transition group VIII of the Periodic Table, either alone or together with at least one metal of transition group I or VII of the Periodic Table, in an amount of from 0.01 to 30% by weight, based on the total weight of the catalyst, applied to a support containing macropores, the support comprises, as a support component, boron(III) oxide in an amount of from 10 to 100% by weight, based on the total weight of the support.
Abstract: Disclosed herein is a moisture-absorbing and desorbing polymer, characterized in that, the said polymer is an organic high-molecular substance containing 1.0-8.0 meq/g of carboxyl group of a potassium type and having a cross-linking structure.
Abstract: The present invention provides a method for producing precursor polymers which decompose to a substantially pure refractory metal carbide or refractory metal boride. The method comprises mixing a transition metal compound with either (a) an organometallic, or (b) a backbone polymer comprising a plurality of unsaturated carbon-carbon bonds. The mixing occurs under conditions effective to form organo-transition metal complexes The organometallic (a), comprises either a borane, a carborane, or an organometallic comprising a metal and at least one unsaturated carbon-carbon bond. When an organometallic (a) is used, the transition metal complexes must be polymerized to form the precursor polymers. When a backbone polymer (b) is used, the transition metal complexes, themselves, comprise the precursor polymers. The refractory metal carbides or metal borides formed upon decomposition of these precursor polymers may be used to make ceramic matrix composites and high temperature coatings.
Abstract: A process for producing a superabsorbent polymer is described. The process that entails a continuous hydrolysis of an aqueous emulsion of crosslinked or uncrosslinked polyacrylonitrile in the form of fine particles is carried out in a cascade of stirred tanks. The reaction with alkali-hydroxide solution an aqueous-alcoholic medium at 60 to 100° C. yields polymers that are suitable for the preparation of hygiene products, water-storing materials in agriculture, and sheathing of electrical cables.
Abstract: A process for the preparation of superabsorbers is disclosed. The process entails subjecting a polyacrylonitrile precipitation polymer alkaline hydrolysis to obtain a hydrolysis product. The hydrolysate that may optionally be neutralized is dried and ground and optionally modified by crosslinking of its surface. The inventive superabsorber is suitable for the preparation of nappies, incontinence articles, water-storage materials and electric cable coverings.
Type:
Application
Filed:
April 16, 2001
Publication date:
November 29, 2001
Inventors:
Gisbert Michels, Gunter Sackmann, Klaus Struss
Abstract: The present invention involves a method of making a multiblock copolymer containing two or more types of sequences of derivatives of acrylic acid with at least one derivative being acrylic acid salt and at least one being acrylamide.
Type:
Application
Filed:
April 19, 2001
Publication date:
November 22, 2001
Applicant:
Replication Medical, Inc.
Inventors:
Vladimir A. Stoy, Petr Stehlicek, Zdena Kozlova, Tomas Drunecky
Abstract: A process for the preparation of superabsorbent polymers by alkaline hydrolysis of polyacrylonitrile emulsions is disclosed. In an embodiment of the invention the process comprise preparing a PAN emulsion, subjecting the emulsion to alkaline hydrolysis, neutralizing the hydrolysate followed by drying, granulation and modifying the surface of the granular polymer by crosslinking. The process is characterized in that the isolation of the superabsorbent polymer entails neither alcohols nor organic solvents.
Abstract: The invention relates to a process for the hydrogenation of a polymer composed of diene monomer units and nitrile group containing monomer units in which crosslinks formed as a result of the hydrogenation are broken by adding, before, during or after the hydrogenation, a compound that satisfies the formula R1—N (H) —X (I) or (R1) (R2)C═N—Y (II), where R1 is a hydrogen atom, an alkyl or cycloalkyl group with 1-30 carbon atoms, or an aromatic group with 6-30 carbon atoms and
Type:
Application
Filed:
February 9, 2001
Publication date:
September 20, 2001
Inventors:
Johannes W. Belt, Jacobus A.A. Vermeulen, Nikhil K. Singha, Olav M. Aagaard, Mike Kostermann
Abstract: An antimicrobial agent utilizes a resin having acrylonitrile and styrene and/or a conjugated diene as units. The antimicrobial agent includes a metal-salt-containing copolymer, and the metal-salt-containing copolymer is obtained by treating a copolymer containing acrylonitrile and at least one of styrene and a conjugated diene as units with an acid to thereby introduce acid radicals into the copolymer, and converting at least part of the acid radicals into a salt of at least one metal selected from among Ag, Cu, and Zn.
Abstract: A process for modifying superabsorbent polymers is disclosed. The surface of a polymer containing hydrolyzed polyacrylonitrile in the form of particulates, is modified by crosslinking in a water/alcohol reaction mixture and in the presence of silica. The resulting product features improved absorbency under load and lesser degree of gel blocking.
Abstract: Water-soluble homo- and/or copolymers containing alkali metal and/or alkaline earth metal carboxylate groups and based on acrylic or methacrylic derivatives, and corresponding water-soluble homo- and/or copolymers containing carboxyl groups and homo- and/or copolymers containing ammonium carboxylate groups are provided, which homo- and/or copolymers possess excellent suitability for increasing the viscosity of aqueous systems, in particular of print pastes for textile treatment.
Type:
Application
Filed:
February 1, 2001
Publication date:
September 6, 2001
Inventors:
Thomas Gross, Siegfried Korte, Rolf-Volker Meyer, Hans-Jorg Seiler
Abstract: A polymer composition useful to produce a vulcanizate having improved compound scorch safety is described. The polymer composition includes three components. The first component is a polymer selected from the group comprising nitrile polymers and ethylene polymers. The second component is a salt of a strong base and a weak acid, the salt comprising a metal selected from Group I of the Periodic Table of Elements. The third component is a vulcanization system comprising an inorganic peroxide compound and a sulfur containing compound. The polymer compositions may further comprise optional ingredients such as one or more of: a polycarbodiimide and a filler. Vulcanizates produced from the polymer composition have a surprising and unexpected combination of properties.
Abstract: The present invention is a method of making acrylonitrile copolymers having multi block structure comprising acrylic acid, acryl amids and acrylamidine hydrophilic groups in hydrophilic blocks and residual nitrile groups in hydrophobic blocks, by partial hydrolysis of polyacrylonitrile to a predetermined hydrolysis conversion at which the hydrolysis is self terminating by a process that improves quality and reduces product heterogeneity.
Abstract: Polar polymers having the following formula:
FG-(Q)d-Rn-Z-J-[A(R1R2R3)]x (I)
wherein FG is H or a protected or non-protected functional group; Q is a polar hydrocarbyl group derived by incorporation of a polar compound selected from group consisting of esters, amides, and nitrites of acrylic and methacrylic acid, and mixtures thereof; d is an integer from 10 to 2000; R is a saturated or unsaturated hydrocarbyl group derived by incorporation of a compound selected from the group consisting of conjugated diene hydrocarbons, alkenylsubstituted aromatic hydrocarbons, and mixtures thereof; n is an integer from 0 to 5; Z is a branched or straight chain hydrocarbon group which contains 3-25 carbon atoms, optionally containing aryl or substituted aryl groups; J is oxygen, sulfur, or nitrogen; [A(R1R2R3)]x is a protecting group, in which A is an element selected from Group IVa of the Periodic Table of Elements; R1, R2, and R3 are each independently selected from the group consisting
Type:
Grant
Filed:
June 30, 1998
Date of Patent:
April 24, 2001
Assignee:
FMC Corporation
Inventors:
Robert J. Letchford, James A. Schwindeman, Conrad W. Kamienski, Roderic P. Quirk
Abstract: A permselective graft polymer is disclosed that is formed by converting into intermediate reactive sites a portion of the cyano groups of a backbone polymer containing —CH2—CH(—C≡N)— units, and grafting polyalkylene oxide polymer chains to the backbone polymer through the reactive sites. Either the backbone polymer of a polymer resin or a permselective polymer membrane can be grafted. When a resin is used, it is formed into a permselective polymer membrane using known methods. The resulting permselective membrane can be formed into hollow fibers or flat sheets for the encapsulation of living cells. The encapsulated cells are then implanted into a patient in need of the biologically active factors produced by the cells. The permselective graft polymer membrane exhibits good molecular diffusion with minimal protein adsorption.
Type:
Grant
Filed:
January 31, 1998
Date of Patent:
January 30, 2001
Assignee:
Neurotech, SA
Inventors:
Frank Gentile, Molly Shoichet, Milton Harris