Hydrogel Compositions Patents (Class 524/916)
  • Patent number: 5362768
    Abstract: 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: Grant
    Filed: July 30, 1993
    Date of Patent: November 8, 1994
    Assignee: Pilkington Visioncare, Inc.
    Inventors: Syed H. Askari, Shao C. Jeang, Herman H. Neidlinger
  • Patent number: 5338428
    Abstract: 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: Grant
    Filed: May 28, 1993
    Date of Patent: August 16, 1994
    Assignee: California Institute of Technology
    Inventors: Thomas Zewert, Michael G. Harrington
  • Patent number: 5332524
    Abstract: 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: Grant
    Filed: April 20, 1992
    Date of Patent: July 26, 1994
    Assignee: Valkyrie Scientific Proprietary, L.C.
    Inventor: Joseph B. Kaylor
  • Patent number: 5331059
    Abstract: 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: Grant
    Filed: November 12, 1992
    Date of Patent: July 19, 1994
    Assignee: Cassella Aktiengesellschaft
    Inventors: Friedrich Engelhardt, Rudiger Funk, Ulrich Riegel, Gerlinde Ebert, Hanss-Jerg Kleiner
  • Patent number: 5322880
    Abstract: 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: Grant
    Filed: November 10, 1993
    Date of Patent: June 21, 1994
    Assignee: Borden, Inc.
    Inventors: Peter S. Columbus, John Anderson, Yogeshbhai B. Patel
  • Patent number: 5319046
    Abstract: 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: Grant
    Filed: January 31, 1989
    Date of Patent: June 7, 1994
    Assignee: Elchrom, Ltd.
    Inventors: Branko Kozulic, Klaus Mosbach
  • Patent number: 5306749
    Abstract: 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: Grant
    Filed: June 15, 1993
    Date of Patent: April 26, 1994
    Assignee: Borden, Inc.
    Inventors: Peter S. Columbus, John Anderson, Yogeshbai B. Patel
  • Patent number: 5284897
    Abstract: 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: Grant
    Filed: November 16, 1992
    Date of Patent: February 8, 1994
    Assignee: Borden, Inc.
    Inventors: Peter S. Columbus, John Anderson, Yogeshbhai B. Patel
  • Patent number: 5275773
    Abstract: 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: Grant
    Filed: January 29, 1992
    Date of Patent: January 4, 1994
    Assignee: Nippon Shokubai Co., Ltd.
    Inventors: Yoshio Irie, Takumi Hatsuda, Koichi Yonemura
  • Patent number: 5252628
    Abstract: 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: Grant
    Filed: December 7, 1989
    Date of Patent: October 12, 1993
    Assignee: Lions Eye Institute of Western Australia, Inc.
    Inventors: Traian V. Chirila, Ian J. Constable, Richard L. Cooper
  • Patent number: 5219923
    Abstract: 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: Grant
    Filed: August 15, 1990
    Date of Patent: June 15, 1993
    Assignee: AT Biochem, Inc.
    Inventor: Robert Shorr
  • Patent number: 5217026
    Abstract: 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: Grant
    Filed: April 6, 1992
    Date of Patent: June 8, 1993
    Assignee: Kingston Technologies, Inc.
    Inventors: George P. Stoy, Vladimir A. Stoy
  • Patent number: 5196456
    Abstract: 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: Grant
    Filed: May 13, 1988
    Date of Patent: March 23, 1993
    Assignee: Chicopee
    Inventors: Hien V. Nguyen, Franklin Boardman
  • Patent number: 5147956
    Abstract: 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: Grant
    Filed: May 9, 1990
    Date of Patent: September 15, 1992
    Assignee: Allied Colloids Ltd.
    Inventor: Adrian S. Allen
  • Patent number: 5124421
    Abstract: 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: Grant
    Filed: December 19, 1990
    Date of Patent: June 23, 1992
    Assignee: Ceskoslovenska Akademie Ved
    Inventors: Karel Ulbrich, Vladnir Subr
  • Patent number: 5112902
    Abstract: 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: Grant
    Filed: May 17, 1990
    Date of Patent: May 12, 1992
    Assignee: Nippon Gohsei Kagaku Kogyo Kabushiki Kaisha
    Inventors: Tetsuo Moriya, Susumu Kondo, Shinji Sanuki
  • Patent number: 5110851
    Abstract: 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: Grant
    Filed: January 8, 1990
    Date of Patent: May 5, 1992
    Assignee: Calgon Corporation
    Inventors: Wood E. Hunter, Gary P. Craun
  • Patent number: 5102938
    Abstract: 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: Grant
    Filed: June 5, 1990
    Date of Patent: April 7, 1992
    Assignee: Minnesota Mining and Manufacturing Company
    Inventor: Gary P. Roberts
  • Patent number: 5096944
    Abstract: 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: Grant
    Filed: April 26, 1990
    Date of Patent: March 17, 1992
    Assignee: Nippon Gohsei Kagaku Kabushiki
    Inventors: Tomiji Itou, Tetsuo Moriya, Susumu Kondo
  • Patent number: 5068298
    Abstract: 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: Grant
    Filed: June 25, 1990
    Date of Patent: November 26, 1991
    Assignee: Cassella Aktiengesellschaft
    Inventors: Friedrich Engelhardt, Ulrich Riegel, Joachim Gersdorf, Hans-Jerg Kleiner
  • Patent number: 5066745
    Abstract: 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: Grant
    Filed: May 29, 1990
    Date of Patent: November 19, 1991
    Assignee: Cassella Aktiengesellschaft
    Inventors: Friedrich Engelhardt, Ulrich Riegel, Joachim Gersdorf, Hans-Jerg Kleiner
  • Patent number: 5055517
    Abstract: 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: Grant
    Filed: March 31, 1989
    Date of Patent: October 8, 1991
    Assignee: AT Biochem
    Inventors: Robert Shorr, Tikam Jain
  • Patent number: 5039459
    Abstract: 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: Grant
    Filed: December 15, 1989
    Date of Patent: August 13, 1991
    Assignee: Johnson & Johnson Vision Products, Inc.
    Inventors: Ture Kindt-Larsen, John C. Heaton, Edmund C. Rastrelli, Gregory A. Hill
  • Patent number: 5011875
    Abstract: 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: Grant
    Filed: March 26, 1990
    Date of Patent: April 30, 1991
    Assignees: Hiroshima Kasei Ltd., Mitsubishi Jidosha Kogyo Kabushiki Kaisha
    Inventors: Yuji Yamamoto, Hideyuki Shigematsu, Hiroshi Tanaka, Ryo Ashikawa, Tatsuo Ishida
  • Patent number: 5002792
    Abstract: 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: Grant
    Filed: July 3, 1989
    Date of Patent: March 26, 1991
    Assignee: Medtronic, Inc.
    Inventor: Brett R. Vegoe
  • Patent number: 5000955
    Abstract: 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: Grant
    Filed: July 23, 1990
    Date of Patent: March 19, 1991
    Assignee: Tyndale Plains-Hunter Ltd.
    Inventors: Francis E. Gould, Christian W. Johnston, George E. Seems
  • Patent number: 4999210
    Abstract: 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: Grant
    Filed: December 7, 1989
    Date of Patent: March 12, 1991
    Assignee: Becton, Dickinson and Company
    Inventors: Donald D. Solomon, M. Parke Byron
  • Patent number: 4905700
    Abstract: 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: Grant
    Filed: February 5, 1988
    Date of Patent: March 6, 1990
    Assignee: Ed. Geistlich AG fur Chemische Industrie
    Inventors: Heinrich Wokalek, Wolfgang Strasser
  • Patent number: 4904715
    Abstract: 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: Grant
    Filed: August 11, 1988
    Date of Patent: February 27, 1990
    Assignee: Calgon Corporation
    Inventors: Wood E. Hunter, Gary P. Craun
  • Patent number: 4892533
    Abstract: 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: Grant
    Filed: August 4, 1988
    Date of Patent: January 9, 1990
    Assignee: Arco Chemical Technology, Inc.
    Inventor: Bi Le-Khac
  • Patent number: 4806434
    Abstract: 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: Grant
    Filed: July 8, 1985
    Date of Patent: February 21, 1989
    Assignee: Fuji Photo Film Co., Ltd.
    Inventor: Masashi Ogawa
  • Patent number: 4794140
    Abstract: 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: Grant
    Filed: November 30, 1987
    Date of Patent: December 27, 1988
    Assignee: American Colloid Company
    Inventor: William Alexander
  • Patent number: 4794166
    Abstract: 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: Grant
    Filed: July 27, 1987
    Date of Patent: December 27, 1988
    Assignee: Cassella Aktiengesellschaft
    Inventors: Friedrich Engelhardt, Manfred Schrod, Manfred Ziegelmayer, Josef Hilbig, Reinhard Donges
  • Patent number: 4778836
    Abstract: 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: Grant
    Filed: June 27, 1985
    Date of Patent: October 18, 1988
    Assignee: Allied Colloids Limited
    Inventors: David Farrar, John Robinson, Peter Flesher
  • Patent number: 4771089
    Abstract: 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: Grant
    Filed: July 10, 1985
    Date of Patent: September 13, 1988
    Assignee: Minnesota Mining and Manufacturing Co.
    Inventor: Ronald F. Ofstead
  • Patent number: 4766173
    Abstract: 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: Grant
    Filed: May 11, 1987
    Date of Patent: August 23, 1988
    Assignee: Nalco Chemical Company
    Inventors: Kristy M. Bailey, Patrick J. Marek
  • Patent number: 4749592
    Abstract: 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: Grant
    Filed: September 11, 1986
    Date of Patent: June 7, 1988
    Assignee: Minnesota Mining and Manufacturing Company
    Inventors: Alton J. Gasper, Charles D. Wright
  • Patent number: 4737533
    Abstract: 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: Grant
    Filed: April 10, 1987
    Date of Patent: April 12, 1988
    Assignee: Rhone-Poulenc Chimie
    Inventors: Dominique Charmot, Jean-Claude Daniel
  • Patent number: 4725379
    Abstract: 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: Grant
    Filed: January 8, 1986
    Date of Patent: February 16, 1988
    Assignee: Institut Francais du Petrole
    Inventors: Pierre Baumgartner, Bernard Boute, Pierre Galtier
  • Patent number: 4716203
    Abstract: 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: Grant
    Filed: September 5, 1986
    Date of Patent: December 29, 1987
    Assignee: American Cyanamid Company
    Inventors: Donald J. Casey, Peter K. Jarrett, Louis Rosati
  • Patent number: 4709767
    Abstract: 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: Grant
    Filed: January 6, 1986
    Date of Patent: December 1, 1987
    Assignee: American Colloid Company
    Inventor: William Alexander
  • Patent number: 4690788
    Abstract: 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: Grant
    Filed: November 5, 1985
    Date of Patent: September 1, 1987
    Assignee: Dai-Ichi Kogyo Seiyaku Co., Ltd.
    Inventors: Akira Yada, Shusaku Matsumoto, Yoshihiro Kawamori, Takao Saito, Tadashi Nishiyama, Yoshitugu Adachi
  • Patent number: 4680336
    Abstract: 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: Grant
    Filed: February 19, 1985
    Date of Patent: July 14, 1987
    Assignee: Vistakon, Inc.
    Inventors: Hans O. Larsen, Ture Kindt-Larsen
  • Patent number: 4668715
    Abstract: 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: Grant
    Filed: December 5, 1985
    Date of Patent: May 26, 1987
    Assignee: Nalco Chemical Company
    Inventor: Kenneth G. Phillips
  • Patent number: 4666964
    Abstract: 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: Grant
    Filed: April 11, 1985
    Date of Patent: May 19, 1987
    Assignee: Calgon Corporation
    Inventors: Wood E. Hunter, Gary P. Craun
  • Patent number: 4663075
    Abstract: 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: Grant
    Filed: December 4, 1985
    Date of Patent: May 5, 1987
    Assignee: National Starch and Chemical Corporation
    Inventors: Wen B. Chiao, Dilip K. Ray-Chaudhuri
  • Patent number: 4582452
    Abstract: 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: Grant
    Filed: June 1, 1984
    Date of Patent: April 15, 1986
    Assignee: Dai-Ichi Kogyo Seiyaku Co., Ltd.
    Inventors: Mineo Sabi, Kinya Yokota, Hiroshi Nishiguchi, Hiroshi Hotta, Satoshi Hiratsuna
  • Patent number: 4548847
    Abstract: 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: Grant
    Filed: January 9, 1984
    Date of Patent: October 22, 1985
    Assignee: Kimberly-Clark Corporation
    Inventors: Gerard M. Aberson, Gerard J. F. Ring
  • Patent number: 4530943
    Abstract: 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: Grant
    Filed: July 29, 1983
    Date of Patent: July 23, 1985
    Assignee: Chemische Fabrik Stockhausen GmbH
    Inventors: Wolfgang Hubner, Helmut Klein, Erhard Goldacker, Otto Schroers
  • Patent number: RE32834
    Abstract: 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: Grant
    Filed: May 11, 1987
    Date of Patent: January 17, 1989
    Assignee: Freeman Chemical Corporation
    Inventors: Howard P. Cordts, Joan E. Karloske