Hydrogel Compositions Patents (Class 524/916)
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Patent number: 5362768Abstract: A polymeric composition suitable for use in ophthalmic devices such as contact lenses, intraocular lenses and other medical and non-medical devices which composition comprises a copolymer that incorporates repeating units containing a solvolyzable group and various desired hydrophilic repeating units in predetermined ratios, which copolymer is mechanically stable and upon hydration the dimensions of polymeric articles which as formed therefrom can be controlled. In particular, the hydrophilic compositions resulting from the invention are user in applications where stresses and distortions of the polymer article due to water absorption etc. must be minimized or, if possible, eliminated.Type: GrantFiled: July 30, 1993Date of Patent: November 8, 1994Assignee: Pilkington Visioncare, Inc.Inventors: Syed H. Askari, Shao C. Jeang, Herman H. Neidlinger
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Patent number: 5338428Abstract: Electrophoresis support media which include one or more poly(N-Acylalkylenimine) polymers (PAEI). The polymers have the formula ##STR1## wherein m and p are between 1 and 3, n is between about 100 and 10,000, where R is an alkyl, perfluoroalkyl or phenyl group and wherein R' is H or an alkyl group. These polymers can be used in place of polyacrylamide gels, agar gels and agarose gels. PAEI polymers may be cross-linked with various cross-linking agents to provide electrophoresis support media with a wide range of pore sizes and physical strength.Type: GrantFiled: May 28, 1993Date of Patent: August 16, 1994Assignee: California Institute of TechnologyInventors: Thomas Zewert, Michael G. Harrington
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Patent number: 5332524Abstract: Particles of water soluble polymers such as poly(olefin oxides) are formulated to readily dissolve without agglomerating by associating polymer particles with particles of gas producing compounds, suitably a bicarbonate and an acid salt, which are non-reactive to the polymer but produce gas when wetted with water whereby the generated gas maintains polymer particles in separation as the particles dissolve.Type: GrantFiled: April 20, 1992Date of Patent: July 26, 1994Assignee: Valkyrie Scientific Proprietary, L.C.Inventor: Joseph B. Kaylor
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Patent number: 5331059Abstract: The present invention relates to a hydrophilic, highly swellable hydrogel based on (co)polymerized hydrophilic monomers or based on graft (co)polymers, characterized in that it has been surface-modified by means of a mixture ofA) one or more diglycidyl phosphonates andB) one or more other reactive compounds which are capable of reacting with the functional groups in the polymer, to a process for the preparation thereof, to the use thereof, and to diglycidyl phosphonate-containing crosslinking agent mixtures.Type: GrantFiled: November 12, 1992Date of Patent: July 19, 1994Assignee: Cassella AktiengesellschaftInventors: Friedrich Engelhardt, Rudiger Funk, Ulrich Riegel, Gerlinde Ebert, Hanss-Jerg Kleiner
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Patent number: 5322880Abstract: A water based thixotropic adhesive gel is disclosed which consists essentially of: water; partially hydrolyzed polyvinyl alcohol, or wherein a portion of the polyvinyl alcohol is replaced with polyvinylpyrrolidone; a water-soluble high viscosity thickening agent polymer which is compatible with the polyvinyl alcohol and which imparts thixotropic properties to the gel; a water-soluble plasticizer for the polyvinyl alcohol; and a watersoluble defoamer in proportion of ingredients so that the viscosity of the adhesive will break down when a flexible tube or squeeze bottle dispenser is finger-pressed and have a sufficiently low viscosity to allow for easy extrusion from an orifice having a diameter of about 0.06 to 0.15 inches. When pressure is released, after the desired amount of adhesive has flown out of the dispenser, the adhesive quickly reverts to very close to its original gel state so that it will not run on a vertical surface on porous and semiporous surfaces such as paper.Type: GrantFiled: November 10, 1993Date of Patent: June 21, 1994Assignee: Borden, Inc.Inventors: Peter S. Columbus, John Anderson, Yogeshbhai B. Patel
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Patent number: 5319046Abstract: A novel synthesis of N-acryloyl-tris-(hydroxymethyl)aminomethane (NAT) is described. The polymerization kinetics and transparency of the poly(NAT) gels crosslinked by a crosslinker (CL) e.g. N,N'-methylenebisacrylamide (Bis), i.e. poly(NAT+Bis) polymer, are shown. Poly(NAT+Bis) gradient (4-24%) gels were prepared and found to resolve native proteins according to their size. The exclusion limit of these gels is over 3.times.10.sup.6 Da. This is more than threefold higher than the exclusion limit of the polyacrylamide gradient gel of the same concentration. Therefore poly(NAT+CL) gels are better than polyacrylamide gels for the resolution of large proteins. It was demonstrated that poly(NAT+CL)-polyacrylamide composite gels could be prepared. The poly(NAT+CL) gels were found to be advantageous also for isoelectric focussing in carrier ampholytes or immobilized pH gradients. Poly(NAT+CL) gels are also very good for separation of nucleic acids.Type: GrantFiled: January 31, 1989Date of Patent: June 7, 1994Assignee: Elchrom, Ltd.Inventors: Branko Kozulic, Klaus Mosbach
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Patent number: 5306749Abstract: A water based thixotropic adhesive gel is disclosed which comprises; an aqueous emulsion of polyvinyl acetate in an amount sufficient to form adhesive bonds on wood; partially hydrolyzed polyvinyl alcohol in an amount sufficient to provide wet tack of the adhesive; glyoxal in an amount sufficient to provide water resistance to the adhesive; and wood flour in an amount sufficient to increase the water resistance imparted by the glyoxal and to provide sanding and staining properties to the adhesive; and xanthan gum in an amount sufficient to provide a thixotropic index and viscosity allowing extrusion of the gel from a flexible dispenser having a dispensing opening of about 0.073 inches in diameter by applying finger-pressure to the dispenser while, upon extrusion, the gel forms a bead which does not run when applied in a horizontal line on wood in a vertical plane.Type: GrantFiled: June 15, 1993Date of Patent: April 26, 1994Assignee: Borden, Inc.Inventors: Peter S. Columbus, John Anderson, Yogeshbai B. Patel
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Patent number: 5284897Abstract: A water based thixotropic adhesive gel is disclosed which consists essentially of: water; partially hydrolyzed polyvinyl alcohol, or wherein a portion of the polyvinyl alcohol is replaced with polyvinylpyrrolidone; a water-soluble high viscosity thickening agent polymer which is compatible with the polyvinyl alcohol and which imparts thixotropic properties to the gel; a water-soluble plasticizer for the polyvinyl alcohol; and a watersoluble defoamer in proportion of ingredients so that the viscosity of the adhesive will break down when a flexible tube or squeeze bottle dispenser is finger-pressed and have a sufficiently low viscosity to allow for easy extrusion from an orifice having a diameter of about 0.06 to 0.15 inches. When pressure is released, after the desired amount of adhesive has flown out of the dispenser, the adhesive quickly reverts to very close to its original gel state so that it will not run on a vertical surface on porous and semiporous surfaces such as paper.Type: GrantFiled: November 16, 1992Date of Patent: February 8, 1994Assignee: Borden, Inc.Inventors: Peter S. Columbus, John Anderson, Yogeshbhai B. Patel
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Patent number: 5275773Abstract: A method for the production of a particulate hydrated gel polymer, which includes heating a hydrated gel polymer possessed of a cross-linked structure to a temperature in the range of from 45.degree. to 90.degree. C. and extruding the resultant hot hydrated gel polymer through a perforated plate containing holes of a diameter in the range of from 6.5 to 18 mm and an absorbent resin which includes drying the resultant particulate hydrated gel polymer.Type: GrantFiled: January 29, 1992Date of Patent: January 4, 1994Assignee: Nippon Shokubai Co., Ltd.Inventors: Yoshio Irie, Takumi Hatsuda, Koichi Yonemura
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Patent number: 5252628Abstract: A method of making pigmented hydrophilic polymers in such a manner that the resulting polymers absorb ultraviolet and visible radiation, and that no migration, separation or leaching of the pigment can take place, is disclosed. The polymer compositions comprise blends of hydrophilic polymers with melanin pigments, the latter being synthesized on the hydrophilic polymer matrix. The disclosed polymer compositions are useful in the manufacture of ocular devices, particularly intraocular lenses and aphakic contact lenses capable of absorbing ultraviolet and visible radiation, at wavelengths between 300 and 700 nanometers, to the same extent as the natural crystalline lens of the eye. The disclosed method is also useful to impart photoprotective properties to the already made said ocular devices.Type: GrantFiled: December 7, 1989Date of Patent: October 12, 1993Assignee: Lions Eye Institute of Western Australia, Inc.Inventors: Traian V. Chirila, Ian J. Constable, Richard L. Cooper
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Patent number: 5219923Abstract: Electrophoretic media based on polymers with novel structures are disclosed. The polymers are formed by polymerization of acrylamide monomers, such as N-methylolacrylamide, with cross-linking agents or comonomer agents such as tetraethylene diacrylate and bisacrylamide methylether.Type: GrantFiled: August 15, 1990Date of Patent: June 15, 1993Assignee: AT Biochem, Inc.Inventor: Robert Shorr
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Patent number: 5217026Abstract: The present invention guidewire involves an elongated, non-hydrogel core element forming an inner part of the device, and an integral outside tubular layer of elastomeric hydrogel ("hydrogel sleeve"). This outer hydrogel layer has unique physical characteristics. They are (a) Gradient of chemical composition with increasing concentration of polar groups in the outward direction away from the core element; (b) Gradient of swelling in contact with water with water content increasing in the outward direction away from the core element; (c) Compressive stress in the outer hydrophilic layer causing the hydrogel in that layer to swell to a water content lower than its equilibrium value in a free-swelling state; and, optionally, (d) Inward-directed radial stress pushing the outside hydrogel layer constantly against the inner core element.Type: GrantFiled: April 6, 1992Date of Patent: June 8, 1993Assignee: Kingston Technologies, Inc.Inventors: George P. Stoy, Vladimir A. Stoy
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Patent number: 5196456Abstract: Superabsorbents made by the process of electron beam initiated polymerization of partially neutralized acrylic acid having improved absorbencies when a trivalent cationic salt, for example, Aluminum Acetate or a tetravalent cationic salt, for example, Platinum Tetrachloride, are added to the partially neutralized acrylic acid solution before polymerization is initiated.Type: GrantFiled: May 13, 1988Date of Patent: March 23, 1993Assignee: ChicopeeInventors: Hien V. Nguyen, Franklin Boardman
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Patent number: 5147956Abstract: A water soluble, substantially linear, polymer is made by copolymerization of a water soluble blend of monoethylenically unsaturated monomers comprising carboxylic acid monomers such as acrylic acid and a hydroxylic monomer of the formula CHR.sup.1 .dbd.CR.sup.2 --Y--M.sub.a --H where R.sup.1 is hydrogen or carboxy, R.sup.2 is hydrogen, carboxy or methyl, Y is O, CH.sub.2 O or COO, M is alkyleneoxy and a is at least 5. This polymer can be cross linked, generally after being shaped by extrusion or other shaping of an aqueous solution of the polymer, to form cross linkages between the carboxyl and hydroxyl groups. The shaped elements can have water absorbency and can be in the form of, for instance, fibers or films.Type: GrantFiled: May 9, 1990Date of Patent: September 15, 1992Assignee: Allied Colloids Ltd.Inventor: Adrian S. Allen
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Patent number: 5124421Abstract: The solution pertains to hydrolytically degradable hydrophilic gels consisting of the individual chains of hydrophilic polymer interconnected with crosslinks containing the structure ##STR1## The method for preparation of the hydrolytically degradable gels consists in subjecting hydrophilic monomers or their mixture to the radical polymerization or copolymerization, or to copolymerization with hydrophobic monomers, in the presence of a new compound--N,O-dimethacryloylhydroxylamine--as a crosslinking agent, and, if desired, in the presence of a solvent, whereas the amount of hydrophilic monomers is 50 to 99.8 molar percent related to all monomers present.Type: GrantFiled: December 19, 1990Date of Patent: June 23, 1992Assignee: Ceskoslovenska Akademie VedInventors: Karel Ulbrich, Vladnir Subr
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Patent number: 5112902Abstract: A process for preparing particles of a high water-absorbent resin which comprises mixing a powder of a high water-absorbent resin having a water content of 10 to 60% by weight with a powder of water-soluble high molecular weight compound and drying the mixture. The obtained particles according to the present invention are suitable for use of sanitary goods, water-retaining agents or soil conditioner in the fields of agriculture and horticulture and other various uses.Type: GrantFiled: May 17, 1990Date of Patent: May 12, 1992Assignee: Nippon Gohsei Kagaku Kogyo Kabushiki KaishaInventors: Tetsuo Moriya, Susumu Kondo, Shinji Sanuki
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Patent number: 5110851Abstract: The instant invention is directed to a method for preparing free-flowing, water-soluble polymer gels comprising:(a) reducing the size of water-soluble polymer gels by a size-reduction means, so as to produce polymer gel particles which are less than 1/2 inch in their longest dimension; and(b) adding to the size-reduced polymer gels of Step (a) 0.001 to 20 percent, by weight, of an amphipathic compound, thereby reducing the adhesion of said gel particles to themselves and other substances.The instant invention is also directed to a free-flowing, water-soluble polymer gel admixture comprising:(a) size-reduced, water-soluble polymer gel particles, wherein said gel particles are less than 1/2 inch in their longest dimension; and(b) an amphipathic compound.Type: GrantFiled: January 8, 1990Date of Patent: May 5, 1992Assignee: Calgon CorporationInventors: Wood E. Hunter, Gary P. Craun
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Patent number: 5102938Abstract: A hydrophilic polyurethane prepolymer in a compatible, water-immiscible solvent or water-immiscible solvent blend having a solids content of greater than about 10 and less than about 50 percent prepolymer in the solvent or solvent blend. This composition reacts with water at about a 1:1 ratio by volume to produce an excellent gel for use in sealing water containing structures and soil stabilization. In the cure process, the compositions of the present invention expand less than 50%, and preferably less than 30%.Type: GrantFiled: June 5, 1990Date of Patent: April 7, 1992Assignee: Minnesota Mining and Manufacturing CompanyInventor: Gary P. Roberts
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Patent number: 5096944Abstract: A process for preparing particles of a high water-absorbent resin which comprises mixing a powder of a high water-absorbent resin with a solution of a sorbitan surfactant having an HLB of 2.1 to 5.0 dissolved in an organic solvent, volatilizing the organic solvent from the mixture to give a resin powder with a content of the organic solvent of not more than 5% by weight, adding water to the mixture to adjust a water content in the resin powder to 25 to 60% by weight, adding an inorganic powder to the resin powder, and drying the resulting mixture. The particles of the high water-absorbent resin obtained according to the present invention are suitable for use of sanitary goods, water-retaining agents or soil conditioner in the fields of agriculture and horgiculture and other various uses.Type: GrantFiled: April 26, 1990Date of Patent: March 17, 1992Assignee: Nippon Gohsei Kagaku KabushikiInventors: Tomiji Itou, Tetsuo Moriya, Susumu Kondo
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Patent number: 5068298Abstract: The present invention relates to compounds of the general formula I ##STR1## in which R.sup.1, R.sup.1', R.sup.2, A and n are as defined in the description, a process for their preparation, their use and also hydrogels prepared using them.Type: GrantFiled: June 25, 1990Date of Patent: November 26, 1991Assignee: Cassella AktiengesellschaftInventors: Friedrich Engelhardt, Ulrich Riegel, Joachim Gersdorf, Hans-Jerg Kleiner
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Patent number: 5066745Abstract: Alkenylphosphonic and -phosphinic acid esters of 1,1,1-tris(hydroxymethyl)alkanes and of 2,2-bis-hydroxymethyl-1,3-propanediol are useful as cross-linking agents in polymeric hydrogels.Type: GrantFiled: May 29, 1990Date of Patent: November 19, 1991Assignee: Cassella AktiengesellschaftInventors: Friedrich Engelhardt, Ulrich Riegel, Joachim Gersdorf, Hans-Jerg Kleiner
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Patent number: 5055517Abstract: Electrophoretic media based on polymers with novel structures are disclosed. In one preferred embodiment, the polymers are formed by cross-linking polymerization of N,N-dimethylacrylamide with ethyleneglycol methacrylate. In another preferred embodiment, the polymers are formed by cross-linking polymerization of N,N-dimethylacrylamide and hydroxyethylmethacrylate with N,N-dimethylbisacrylamide.Type: GrantFiled: March 31, 1989Date of Patent: October 8, 1991Assignee: AT BiochemInventors: Robert Shorr, Tikam Jain
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Patent number: 5039459Abstract: Shaped hydrogel articles such as soft contact lenses are prepared by (1) molding or casting a polymerization mixture comprising: (a) a monomer mixture comprising a major proportion of a hydrophilic (meth)acrylate ester such as 2-hydroxyethyl methacrylate, an alkyl (meth)acrylate wherein the alkyl group contains at least four carbon atoms, and a cross-linking monomer; and (b) a water-displaceable diluent, wherein said diluent has a viscosity of at least 100 MPa Sec at 30.degree. C., and wherein said diluent consists essentially of a boric acid ester of certain dihydric alcohols, said dihydric alcohols having Hansen polar (w.sub.p) and Hansen hydrogen bonding (w.sub.h) cohesion parameters falling within the area of a circle defined as having a center at w.sub.h =20.5, w.sub.p =13, and a radius of 8.5, to produce a shaped gel of a copolymer of said monomers and said diluent, and (2) thereafter replacing said diluent with water.Type: GrantFiled: December 15, 1989Date of Patent: August 13, 1991Assignee: Johnson & Johnson Vision Products, Inc.Inventors: Ture Kindt-Larsen, John C. Heaton, Edmund C. Rastrelli, Gregory A. Hill
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Patent number: 5011875Abstract: A corrosion resistant, water expandable composition comprising:(A) 100 parts by weight of at least one material selected from the group consisting of rubbers, thermoplastic resins and mixtures thereof;(B) 10-200 parts by weight of a water-absorbable material; and(C) 5-30 parts by weight of a corrosion inhibitor is disclosed.Type: GrantFiled: March 26, 1990Date of Patent: April 30, 1991Assignees: Hiroshima Kasei Ltd., Mitsubishi Jidosha Kogyo Kabushiki KaishaInventors: Yuji Yamamoto, Hideyuki Shigematsu, Hiroshi Tanaka, Ryo Ashikawa, Tatsuo Ishida
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Patent number: 5002792Abstract: A method for making biomedical devices employing thermoplastic hydrogels on an operant surface thereof is described. The method generally involves heating a thermoplastic hydrogel to a temperature in the range of 50.degree. C. to about 95.degree. C. to a fluid flowable state, dispensing the fluid hydrogel onto the biomedical device and cooling the hydrogel to a substantially solid state. Microwave heating is preferred.Type: GrantFiled: July 3, 1989Date of Patent: March 26, 1991Assignee: Medtronic, Inc.Inventor: Brett R. Vegoe
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Patent number: 5000955Abstract: Thermally reversible polyurethane hydrogels are formed by adding water to a gel forming hydrophilic polyurethane polymer produced by reacting under anhydrous conditions a non-aromatic organic diisocyanate with a glycol component in an NCO/OH mole weight ratio of from about 0.900/1 to about 0.980/1, the glycol component having a number average molecular weight of from about 1000 to 3500 wherein the percentage by weight of the diisocyanate in the reaction mixture is from about 7% to about 20%. The hydrogels are solids at room temperature but liquify at higher temperatures such as body temperature and therefore are useful as carriers for the protection, delivery and sustained release of a variety of active agents including pharmaceuticals, cosmetics, living cells and organisms.Type: GrantFiled: July 23, 1990Date of Patent: March 19, 1991Assignee: Tyndale Plains-Hunter Ltd.Inventors: Francis E. Gould, Christian W. Johnston, George E. Seems
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Patent number: 4999210Abstract: An anti-infective medical article has chlorhexidine bulk distributed throughout a polyurethane base layer and may have a coating layer on the base layer. The coating layer may be chlorhexidine, an antibiotic, or an antithrombogenic agent permeated into the surface or it may be a polymeric surface layer having bulk distributed chlorhexidine laminated onto the base layer. The invention includes a method for preparing the article wherein a homogeneous melt of polymer and chlorhexidine is prepared by twin screw compounding and the melt is extruded to give a medical article having bulk distributed chlorhexidine. The article may then be laminated by dipping into a solution of chlorhexidine and a substantially hydrophilic polymer in a solvent.Type: GrantFiled: December 7, 1989Date of Patent: March 12, 1991Assignee: Becton, Dickinson and CompanyInventors: Donald D. Solomon, M. Parke Byron
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Patent number: 4905700Abstract: An acoustic coupling medium for transmitting ultrasound is disclosed. The medium, which is of use in ultrasonic visualization of the human body, comprises a sheet of hydrogel containing over 90% water, preferably over 95% water. The hydrogel preferably comprises agar, the chains of which are interspersed with chains of polyacrylamide.Type: GrantFiled: February 5, 1988Date of Patent: March 6, 1990Assignee: Ed. Geistlich AG fur Chemische IndustrieInventors: Heinrich Wokalek, Wolfgang Strasser
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Patent number: 4904715Abstract: The instant invention is directed to a method for preparing free-flowing, water-soluble polymer gels comprising:(a) reducing the size of water-soluble polymer gels by a size-reduction means, so as to produce polymer gel particles which are less than 1/2 inch in their longest dimension; and(b) adding to the size-reduced polymer gels of Step (a) 0.001 to 20 percent, by weight, of an amphipathic compound, thereby reducing the adhesion of said gel particles to themselves and other substances.Type: GrantFiled: August 11, 1988Date of Patent: February 27, 1990Assignee: Calgon CorporationInventors: Wood E. Hunter, Gary P. Craun
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Patent number: 4892533Abstract: A copolymer of recurring units of at least one .alpha.,.beta.-unsaturated monomer and recurring units of at least one copolymerizable comonomer comprising, in its preferred embodiment from about 20 to about 80 percent pendant carboxylic acid units and from about 80 to about 20 percent pendant carboxylate salt units, is blended with a heterocyclic carbonate to produce a water-absorbing composition upon curing. The composition is particularly suitable for fiber formation.Type: GrantFiled: August 4, 1988Date of Patent: January 9, 1990Assignee: Arco Chemical Technology, Inc.Inventor: Bi Le-Khac
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Patent number: 4806434Abstract: A medium for electrophoresis comprising an aqueous acrylamide gel formed by crosslinking polymerization of an acrylamide compound and an acrylamide copolymer having at least one specifically selected constitutional repeating unit in the presence of water. The medium may contain a water-soluble polymer and agarose. The medium may contain a modifier such as an anionic surfactant or a compound having at least one carbamoyl group.Type: GrantFiled: July 8, 1985Date of Patent: February 21, 1989Assignee: Fuji Photo Film Co., Ltd.Inventor: Masashi Ogawa
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Patent number: 4794140Abstract: Disclosed is a process for preparing relatively low molecular weight, water absorbing, acrylic polymers for use as drilling fluid additives by aqueous polymerization of (A) an acrylic monomer, such as acrylic acid neutralized 0 to 100 mole percent with, for example, ammonia, and/or an alkali such as Na.sub.2 O.sub.3, and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B). The molecular weight is limited to 1,000 to 50,000, such as by adding a chain transfer agent to the polymerization mixture, to achieve excellent results as a drilling fluid additive. The monomer, such as partially neutralized acrylic acid, is polymerized in aqueous solution in the presence of a polymerization initiator without external heating while allowing water to evaporate off.Type: GrantFiled: November 30, 1987Date of Patent: December 27, 1988Assignee: American Colloid CompanyInventor: William Alexander
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Patent number: 4794166Abstract: A polymer hydrogel substantially free from monomers and oligomers is prepared by contacting a previously prepared polymer hydrogel with a single-phase mixture of water and a solvent and then separating the mixture of water and solvent from the hydrogel.Type: GrantFiled: July 27, 1987Date of Patent: December 27, 1988Assignee: Cassella AktiengesellschaftInventors: Friedrich Engelhardt, Manfred Schrod, Manfred Ziegelmayer, Josef Hilbig, Reinhard Donges
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Patent number: 4778836Abstract: A water soluble or swellable polymer gel is dispersed into a liquid phase to form a fluid composition and is worked while in that composition. The liquid phase is an aqueous solution of an equilibrating agent that substantially prevents aggregation of the particles or dissolution of the polymer during the working. The working may be, for instance, milling, extraction of impurities, extraction of water, transportation or chemical modification. Preferred equilibrating agents are sodium polyacrylate and polydiallyl dimethyl ammonium chloride.Type: GrantFiled: June 27, 1985Date of Patent: October 18, 1988Assignee: Allied Colloids LimitedInventors: David Farrar, John Robinson, Peter Flesher
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Patent number: 4771089Abstract: Miscible blends of solids, non-crosslinked polymers are disclosed. The blends comprise from 2 to 95 parts by weight of a water-insoluble, hydrophobic polymer and, correspondingly from 98 to 5 parts by weight of a hydrophilic polymer. The blends are capable of absorbing at least their own weight in water.Type: GrantFiled: July 10, 1985Date of Patent: September 13, 1988Assignee: Minnesota Mining and Manufacturing Co.Inventor: Ronald F. Ofstead
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Patent number: 4766173Abstract: A method for reducing the residual acrylic acid present in water-insoluble polyacrylic acid water absorbent gel polymers which comprises treating these polymers with at least 0.5 mole of either amino acid cysteine or lysine per mole of acrylic acid present in said waters for at least 15 minutes at a temperature of at least 80.degree. C.Type: GrantFiled: May 11, 1987Date of Patent: August 23, 1988Assignee: Nalco Chemical CompanyInventors: Kristy M. Bailey, Patrick J. Marek
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Patent number: 4749592Abstract: A grouting composition for sealing structures to inhibit water leakage therethrough and for stabilizing soil is provided. The composition is provided as a two-part system. Part A is an aqueous solution of a hydrophililc, water soluble prepolymer having a polyether backbone and terminal active olefinic groups, the olefinic groups being connected to the polyether backbone by linking groups selected from --NH--, --CONH--, --OCONH--, and --NHCONH--, and tertiary amine catalyst. Part B is an aqueous solution of a initiator. Parts A and B are mixed and react to form a gel.Type: GrantFiled: September 11, 1986Date of Patent: June 7, 1988Assignee: Minnesota Mining and Manufacturing CompanyInventors: Alton J. Gasper, Charles D. Wright
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Patent number: 4737533Abstract: Dry material which can be hydrated into an aqueous gel comprising (1) a matrix comprising a macromolecular substance A, capable of forming a porous aqueous gel when it is in the presence of water, (2) a water-soluble linear polymer B, (3) a plasticizer for the macromolecular substance A and, (4) dispersed in the matrix, particles of a polymer C obtained from at least one water-immiscible monomer.The material can be obtained by mixing an aqueous solution of A with the polymer B, the plasticizer and a latex of polymer C, followed by cooling, shaping and drying of the aqueous gel obtained.The dry material can be used in biological applications after rehydration.Type: GrantFiled: April 10, 1987Date of Patent: April 12, 1988Assignee: Rhone-Poulenc ChimieInventors: Dominique Charmot, Jean-Claude Daniel
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Patent number: 4725379Abstract: The invention concerns a process and an apparatus for making a stable solution or dispersion of a hydrosoluble powder.It is characterized by the simultaneous use of a system for withdrawing powder from a vessel (2) e.g. by means of a gas (4), the dilution of the powder in a carrying gas, the driving with said carrying gas, of the obtained dilution, through a transfer duct (10), the passage of the dilution across an electrostatic field (11) and the solubilization in water of a tank (12).The invention is particularly applicable to the dispersion of polyacrylamides used in the technique of enhanced oil recovery.Type: GrantFiled: January 8, 1986Date of Patent: February 16, 1988Assignee: Institut Francais du PetroleInventors: Pierre Baumgartner, Bernard Boute, Pierre Galtier
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Patent number: 4716203Abstract: A diblock copolymer is disclosed having a first block of a polyalkylene oxide and a second block of glycolic acid ester and trimethylene carbonate linkages. A triblock copolymer is disclosed having a middle block obtained from an ethylene oxide homopolymer or a copolymer of ethylene oxide and a cyclic ether. Alternatively, the triblock copolymer middle block is obtained from a copolymer of formula (I): ##STR1## and formula (II): ##STR2## The copolymers are useful in medical and surgical applications.Type: GrantFiled: September 5, 1986Date of Patent: December 29, 1987Assignee: American Cyanamid CompanyInventors: Donald J. Casey, Peter K. Jarrett, Louis Rosati
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Patent number: 4709767Abstract: Disclosed is a process for preparing relatively low molecular weight, water absorbing, acrylic polymers for use as drilling fluid additives by aqueous polymerization of (A) an acrylic monomer, such as acrylic acid neutralized 0 to 100 mole percent with, for example, ammonia, and/or an alkali such as Na.sub.2 O.sub.3, and/or an amine; with (B) acrylamide in a mole ratio of 70 to 100 mole percent (A) to 30:0 mole percent (B). The molecular weight is limited to 1,000 to 50,000, such as by adding a chain transfer agent to the polymerization mixture, to achieve excellent results as a drilling fluid additive. The monomer, such as partially neutralized acrylic acid, is polymerized in aqueous solution in the presence of a polymerization initiator without external heating while allowing water to evaporate off.Type: GrantFiled: January 6, 1986Date of Patent: December 1, 1987Assignee: American Colloid CompanyInventor: William Alexander
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Patent number: 4690788Abstract: A novel process for preparing particles of polymer gel prepared by polymerizing an aqueous solution of water-soluble vinyl monomers which comprises breaking the polymer gel into particles with a breaker device wherein the gel is cut into strips by a pair of rollers having a plurality of annular projections or grooves on their surfaces, the rollers rotating in an opposite direction to each other to engage each other and cut off the gel fed between the rollers, and the strips are then cut into particles by a combination of a fixed cutting blade and a rotating cutting blade. The obtained gel particles are further pulverized into fine round or particles spherical in a vertical type cutter comprising at least one vertically fixed cutting blade and a rotary cutting blade arranged rotatably and vertically, a clearance being provided between an edge of the rotary cutting blade and an edge of the fixed blade.Type: GrantFiled: November 5, 1985Date of Patent: September 1, 1987Assignee: Dai-Ichi Kogyo Seiyaku Co., Ltd.Inventors: Akira Yada, Shusaku Matsumoto, Yoshihiro Kawamori, Takao Saito, Tadashi Nishiyama, Yoshitugu Adachi
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Patent number: 4680336Abstract: A method for forming shaped hydrogel articles such as soft contact lenses wherein hydrophilic monomers are mixed with an inert diluent prior to polymerization, and the diluent is replaced with water following the polymerization. Diluents yielding optically clear hydrogels with good mechanical properties are selected on the basis of their viscosity and their Hanson cohesion parameters relative to the cohesion parameters of the polymeric component of the hydrogel.Type: GrantFiled: February 19, 1985Date of Patent: July 14, 1987Assignee: Vistakon, Inc.Inventors: Hans O. Larsen, Ture Kindt-Larsen
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Patent number: 4668715Abstract: A method of rapidly dissolving finely divided individual particles of water-soluble vinyl addition polymers which comprises adding to water which contains from 0.5 to 10% by weight of a water-soluble surfactant, dry particles of a vinyl addition polymer, which particles have been coated with an oil-soluble emulsifier to provide a discrete organic solvent-free coating about such individual particles, having an HLB value between 4 and 9.Type: GrantFiled: December 5, 1985Date of Patent: May 26, 1987Assignee: Nalco Chemical CompanyInventor: Kenneth G. Phillips
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Patent number: 4666964Abstract: The instant invention is directed to a method for preparing free-flowing, water-soluble polymer gels comprising:(a) reducing the size of water-soluble polymer gels by a size-reduction means, so as to produce polymer gel particles which are less than 1/2 inch in their longest dimension; and(b) adding to the size-reduced polymer gels of Step (a) 0.001 to 20 percent, by weight, of an amphipathic compound, thereby reducing the adhesion of said gel particles to themselves and other substances.The instant invention is also directed to a free-flowing, water-soluble polymer gel admixture comprising:(a) size-reduced, water-soluble polymer gel particles, wherein said gel particles are less than 1/2 inch in their longest dimension; and(b) an amphipathic compound.Type: GrantFiled: April 11, 1985Date of Patent: May 19, 1987Assignee: Calgon CorporationInventors: Wood E. Hunter, Gary P. Craun
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Patent number: 4663075Abstract: Novel gelling agents are prepared by reacting diphenyldiisocyanates with sulfur trioxide in a molar concentration of about 1:2. When the sulfonated diphenyldiisocyanate is added to water in concentrations above 2%, a gel is produced which is stable under acidic conditions at pH levels of about 4 or less.Type: GrantFiled: December 4, 1985Date of Patent: May 5, 1987Assignee: National Starch and Chemical CorporationInventors: Wen B. Chiao, Dilip K. Ray-Chaudhuri
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Patent number: 4582452Abstract: A process for forming a gel by gelling an aqueous solution of a water-soluble polymer with a chromium compound as a gelling agent, in which a copolymer of acrylamide, 0.5 to 40% by mole of an unsaturated sulfonic acid or its salt, and optionally an unsaturated carboxylic acid or its salt having an intrinsic viscosity of at least 10 in 1N-NaNO.sub.3 at 30.degree. C., is used as the water-soluble polymer, and which is availably applied to improvement of water-oil ratio in oil production and to civil engineering for preventing leakage of underground water. The formed gel is very stable in a water system containing salts in high concentrations at high temperatures.Type: GrantFiled: June 1, 1984Date of Patent: April 15, 1986Assignee: Dai-Ichi Kogyo Seiyaku Co., Ltd.Inventors: Mineo Sabi, Kinya Yokota, Hiroshi Nishiguchi, Hiroshi Hotta, Satoshi Hiratsuna
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Patent number: 4548847Abstract: The invention comprises of an anionic polyelectrolyte hydrogel reversibly cross-linked with a polyvalent metal cation having a valence of at least two. This hydrogel may be combined with a removal agent for imparting delayed swelling characteristics when contacted with a water-containing fluid. The delayed swelling allows the water-containing fluid to penetrate or permeate the system before swelling is initiated, thereby providing enhanced wetting prior to the onset of swelling and alleviating gel blockage.Type: GrantFiled: January 9, 1984Date of Patent: October 22, 1985Assignee: Kimberly-Clark CorporationInventors: Gerard M. Aberson, Gerard J. F. Ring
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Patent number: 4530943Abstract: A process is disclosed for the rapid dissolution of a water soluble polymer by mixing the polymer with water and using a hydrophilic wetting agent, wherein the water is introduced under normal mixing conditions into a prepared water-in-oil polymer dispersion that is free of wetting agent, the wetting agent being added after dilution of the prepared water-in-oil dispersion with water. It is preferred that the water be added under pressure through a nozzle.Type: GrantFiled: July 29, 1983Date of Patent: July 23, 1985Assignee: Chemische Fabrik Stockhausen GmbHInventors: Wolfgang Hubner, Helmut Klein, Erhard Goldacker, Otto Schroers
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Patent number: RE32834Abstract: A liquid-filled polyurethane elastomer gel is fabricated from water, organic glycol and a polyisocyanate prepolymer. The prepolymer is formed from organic diisocyanate and organic diol or triol having a molecular weight of 3,000 to 10,000 and containing at least 40 percent by weight ethylene oxide adducts. The prepolymer is mixed with 3 to 20 times its weight of aqueous reactant including 25 to 65 percent by weight water and 75 to 35 percent by weight organic polyol. The resulting stable gel contains aqueous solutions of emulsions dispersed therein as small droplets comprising 75 to 95 percent of the weight of the resulting article. The liquid-filled polyurethane elastomer gel can be cast into shapes or can be formed into globs of random shape.Type: GrantFiled: May 11, 1987Date of Patent: January 17, 1989Assignee: Freeman Chemical CorporationInventors: Howard P. Cordts, Joan E. Karloske