Solid Polymer Derived From Carboxylic Acid Cyclic Ester, E.g., Lactone, Etc. Patents (Class 525/415)
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Patent number: 5550209Abstract: Disclosed are a lactone polymer, a carbonate polymer, a lactone-carbonate random or block copolymer which are mono-dispersed, that is, which have a molecular weight distribution of nearly 1, or, in which purity of a polymer component having a unitary structure is very high, and processes for the preparation thereof which comprise a ring-opening addition reaction of a lactone monomer and/or a cyclic carbonate monomer with a ring-opening initiator in the presence of an organic aluminum-based Lewis acid represented by general formula (I), ##STR1## wherein R is an alkyl group having a carbon number ranging from 1 to 4, Y is independently selected from a substituted group, and p is any one of 1, 2 and 3.Type: GrantFiled: February 28, 1995Date of Patent: August 27, 1996Assignee: Daicel Chemical Industries, Ltd.Inventors: Shohei Inoue, Takuzo Aida, Masaki Akatsuka
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Patent number: 5550173Abstract: A polymer composition comprising at least one structural polymer and at least one oligomer of at least one polymer selected from the group; polyhydroxyalkanoates, polylactide, polycaprolactone and co-polymers thereof.Type: GrantFiled: May 5, 1995Date of Patent: August 27, 1996Assignee: Zeneca LimitedInventors: Timothy Hammond, Jasbinder S. Bal
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Patent number: 5539081Abstract: A lactide polymer composition combining compositional and purity limitations and catalyst optimization or addition of stabilizing agents resulting in a melt-stable polymer is disclosed. The melt-stable lactide polymer comprises a plurality of polylactide polymer chains, residual lactide in concentration of less than 2 percent and water in concentration of less than 1000 parts-per-million. A stabilizing agent in an amount sufficient to reduce depolymerization of the lactide polymer during melt-processing or alternatively, control of catalyst level at a molar ratio of monomer to catalyst greater than 3000:1 is also included in the melt-stable composition. A process for manufacture of a melt-stable lactide polymer composition includes polymerizing a lactide mixture and adding stabilizing agents sufficient to reduce depolymerization of the polylactide during melt-processing, followed by devolatilizing the polylactide to remove monomer and water.Type: GrantFiled: May 22, 1995Date of Patent: July 23, 1996Assignee: Cargill, IncorporatedInventors: Patrick R. Gruber, Jeffrey J. Kolstad, Eric S. Hall, Robin S. Eichen Conn, Christopher M. Ryan
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Patent number: 5536564Abstract: The present invention relates to biodegradable PHA copolymers comprising at least two randomly repeating monomer units (RRMU) wherein the first RRMU has the structure ##STR1## wherein R.sup.1 is H or C.sub.2 alkyl, and n is 1 or 2; the second RRMU has the structure ##STR2## ; and wherein at least 50% of the RRMUs have the structure of the first RRMU. The present invention further relates to plastic articles comprising said biodegradable PHA copolymers. The present invention further relates to an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet comprising a film comprising a PHA of the present invention and an absorbent core positioned between the topsheet and the backsheet.Type: GrantFiled: June 6, 1995Date of Patent: July 16, 1996Assignee: The Procter & Gamble CompanyInventor: Isao Noda
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Patent number: 5536807Abstract: A semi-crystalline film comprised of a lactide polymer. The lactide polymer comprises a plurality of poly(lactide) polymer chains, residual lactide in concentration of less than about 5 percent and water in concentration of less than about 2000 parts-per-million. A process for manufacturing a semi-crystalline film with the lactide polymer composition is also disclosed.Type: GrantFiled: August 23, 1993Date of Patent: July 16, 1996Assignee: Cargill, IncorporatedInventors: Patrick R. Gruber, Jeffrey J. Kolstad, Christopher M. Ryan
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Patent number: 5530074Abstract: This invention relates to materials for medical or veterinary use that possess considerably improved properties with regard to friction. The invention also relates to the production of such materials from existing materials that possess suitable bulk properties, but inappropriate frictional properties. This invention also relates to a hydrophilic coating material that provides improved frictional properties.Type: GrantFiled: June 7, 1995Date of Patent: June 25, 1996Assignee: American Cyanamid CompanyInventors: Peter K. Jarrett, George Jessup, Louis Rosati, Chris Martin, John W. Maney
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Patent number: 5525706Abstract: A nonwoven fabric comprised of a lactide polymer. The lactide polymer comprises a plurality of poly(lactide) polymer chains, residual lactide in concentration of less than about 2 percent and water in concentration of less than about 2000 parts-per-million. A process for manufacturing a nonwoven fabric with the lactide polymer composition is also disclosed.Type: GrantFiled: October 25, 1994Date of Patent: June 11, 1996Assignee: Cargill, IncorporatedInventors: Patrick R. Gruber, Jeffrey J. Kolstad, Christopher M. Ryan, Eric S. Hall, Robin S. Eichen Conn
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Patent number: 5525646Abstract: This invention relates to a bioresorbable material and an article of manufacture of such material for medical use comprising homopolymers, copolymers, or a blend thereof selected from the group of monomers including glycolic acid, lactic acid, caprolactone, trimethylene carbonate, paradioxanone and 1,5 dioxepan-2-one, a plasticizer selected from the group including ethyl, butyl and hexyl esters of acetylated or non-acetylated citric acid, ethyl terminated oligomers of lactic acid, having no less than 2 and no more than 10 units, and lactic acid esters of glycerol, the material comprises 50% of amorphous polymer or polymers to impart to the material plastic malleability substantially without memory.Type: GrantFiled: September 3, 1993Date of Patent: June 11, 1996Inventors: Dan Lundgren, Jan Gottlow, Torbjorn Mathisen
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Patent number: 5522842Abstract: Crystalline, low melting .epsilon.-Caprolactone polymers which undergo accelerated hydrolysis for use, for example, as absorbable coatings for surgical sutures; the polymers bearing basic amine functionalities, ionically or covalently linked to the ester chain, which induce autocatalyzed hydrolysis.Type: GrantFiled: March 11, 1994Date of Patent: June 4, 1996Assignee: Poly-Med, Inc.Inventor: Shalaby W. Shalaby
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Patent number: 5522841Abstract: Block copolymers have one of the block made from hard phase forming monomers and another block made from soft phase forming monomers copolymerized with randomly intermingled units of other soft phase forming monomers. Particularly useful copolymers are initiated with a polyalkylene oxide initiator. The copolymers are useful in forming surgical articles, including both monofilament and multifilament sutures.Type: GrantFiled: December 29, 1994Date of Patent: June 4, 1996Assignee: United States Surgical CorporationInventors: Mark S. Roby, Cheng-Kung Liu, Steven L. Bennett
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Patent number: 5516920Abstract: The invention described novel compounds of formula ##STR1## wherein the general symbols are as defined in claim 1, as stabilisers for protecting organic materials, in particular polymers and lubricants, against thermal, oxidative or light-induced degradation.Type: GrantFiled: September 12, 1994Date of Patent: May 14, 1996Assignee: Ciba-Geigy CorporationInventors: Peter Nesvadba, Samuel Evans, Christoph Krohnke, Jurg Zingg
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Patent number: 5508378Abstract: A method for producing a polylactic acid of the present invention includes the steps of (a) polymerizing a lactide used as a main starting material in a molten state to give a polylactic acid; and (b) further polymerizing the polylactic acid obtained in step (a) in a solid phase by heating at a temperature lower than a melting point of a final polymer product.Type: GrantFiled: January 20, 1995Date of Patent: April 16, 1996Assignee: Shimadzu CorporationInventors: Hitomi Ohara, Seiji Sawa, Tatsushi Kawamoto
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Patent number: 5502116Abstract: The present invention relates to biodegradable PHA copolymers comprising at least two randomly repeating monomer units (RRMU) wherein the first RRMU has the structure ##STR1## wherein R.sup.1 is H or C.sub.2 alkyl, and n is 1 or 2; the second RRMU has the structure ##STR2## and wherein at least 50% of the RRMUs have the structure of the first RRMU. The present invention further relates to plastic articles comprising said biodegradable PHA copolymers. The present invention further relates to an absorbent article comprising a liquid pervious topsheet, a liquid impervious backsheet comprising a film comprising a PHA of the present invention and an absorbent core positioned between the topsheet and the backsheet.Type: GrantFiled: June 7, 1995Date of Patent: March 26, 1996Assignee: The Procter & Gamble CompanyInventor: Isao Noda
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Patent number: 5502159Abstract: A block copolymer for use in the fabrication of bioabsorbable articles such as monofilament surgical sutures is prepared by copolymerizing one or more hard phase forming monomers and 1,4-dioxan-2-one, and then polymerizing one or more hard phase forming monomers with the dioxanone-containing copolymer.Type: GrantFiled: May 1, 1995Date of Patent: March 26, 1996Assignee: United States Surgical CorporationInventors: Cheng-Kung Liu, Steven L. Bennett, John Kennedy, Donald S. Kaplan, Ross R. Muth
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Patent number: 5500465Abstract: Compatibilized blends of a biodegradable hydrophobic polyester, unmodified starch or other similar polysaccharide containing less than 1% water by weight, other biodegradable polymers that may be hydrophobic, plasticizer, and other additives. The blends are produced in the absence of water. The preferred polyester polymer is poly(.epsilon.-caprolactone) and the preferred starch is from corn. A small amount of a unique stretching agent is incorporated to provide high elongations at break, especially in film forming compositions containing a significant amount of starch. The starch is a discontinuous phase that may be completely or partially plasticized and the polyester polymer is the continuous phase. The preferred polymers have unique film forming properties and are resistant to water and moisture.Type: GrantFiled: March 10, 1994Date of Patent: March 19, 1996Assignee: Board of Trustees operating Michigan State UniversityInventors: Mohan Krishnan, Ramani Narayan
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Patent number: 5498379Abstract: Shaped hydrogel articles such as soft contact lenses are prepared by the steps of:(1) molding or casting a polymerization mixture comprising:(a) a monomer mixture comprising a major proportion of one or more hydrophilic monomers such as 2-hydroxyethyl methacrylate, and one or more cross-linking monomers; and(b) an inert, displaceable diluent selected from the group consisting of:(i) ethoxylated alkyl glucoside;(ii) ethoxylated bisphenol A;(iii) polyethylene glycol;(iv) mixture of propoxylated and ethoxylated alkyl glucoside;(v) single phase mixture of ethoxylated or propoxylated alkyl glucoside and C.sub.2-12 dihydric alcohol;(vi) adduct of .epsilon.-caprolactone and C.sub.2-6 alkanediols and triols;(vii) ethoxylated C.sub.3-6 alkanetriol; and(viii) mixtures of one or more of (i) through (vii),under conditions to polymerize said monomer mixture to produce a shaped gel of a copolymer of said monomers and said diluent; and(2) thereafter replacing said diluent with water.Type: GrantFiled: May 31, 1995Date of Patent: March 12, 1996Assignee: Johnson & Johnson Vision Products, Inc.Inventors: Ivan M. Nunez, Frank F. Molock, Laura D. Elliott, James D. Ford
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Patent number: 5489651Abstract: "Living" polymerization methods are described wherein a bimetallic lanthanide complex initiator is reacted with a monomer. Using these methods, link-functionalized polymers can be formed that are capable of being modified after polymerization with various reactants, or to be biodegraded through oxidation or reduction or cleavage. The bimetallic lanthanide complex initiator can be used to polymerize methyl methacrylate in a living fashion. A two-step method of forming a triblock polymer using the bimetallic lanthanide complex initiator is also disclosed.Type: GrantFiled: February 14, 1994Date of Patent: February 6, 1996Assignee: The Regents of the University of CaliforniaInventors: Bruce M. Novak, Lisa S. Boffa
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Patent number: 5484881Abstract: An amorphous film comprised of a lactide polymer. The lactide polymer comprises a plurality of poly(lactide) polymer chains, residual lactide in concentration of less than about 2 percent and water in concentration of less than about 2000 parts-per-million. A process for manufacturing an amorphous film with the lactide polymer composition is also disclosed.Type: GrantFiled: August 23, 1993Date of Patent: January 16, 1996Assignee: Cargill, Inc.Inventors: Patrick R. Gruber, Jeffrey J. Kolstad, Christopher M. Ryan, Eric S. Hall, Robin S. Eichen Conn
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Patent number: 5480868Abstract: A sustained-release preparation which comprises a physiologically active peptide of general formula ##STR1## wherein X represents an acyl group; R.sub.1, R.sub.2 and R.sub.4 each represents an aromatic cyclic group; R.sub.3 represents a D-amino acid residue or a group of the formula ##STR2## wherein R.sub.3 ' is a heterocyclic group; R.sub.5 represents a group of the formula --(CH.sub.2).sub.n --R.sub.5 ' wherein n is 2 or 3, and R.sub.5 ' is an amino group which may optionally be substituted, an aromatic cyclic group or an O-glycosyl group;R.sub.6 represents a group of the formula --(CH.sub.2).sub.n --R.sub.6 ' wherein n is 2 or 3, and R.sub.6 ' is an amino group which may optionally be substituted;R.sub.7 represents a D-amino acid residue or an azaglycyl residue; andQ represents hydrogen or a lower alkyl group, or a salt thereof and a biodegradable polymer having a terminal carboxyl group.Type: GrantFiled: December 7, 1993Date of Patent: January 2, 1996Assignee: Takeda Chemical Industries, ltd.Inventors: Shigeru Kamei, Yasutaka Igari, Yasuaki Ogawa
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Patent number: 5475080Abstract: A lactide polymer coating resulting in a strong, repulpable, high gloss, paper coating. The lactide polymer comprises a plurality of poly(lactide) polymer chains, residual lactide in concentration of less than about 5 percent and water in concentration of less than about 2000 parts-per-million. A process for coating paper with the lactide polymer composition is also disclosed.Type: GrantFiled: March 22, 1993Date of Patent: December 12, 1995Assignee: Cargill, IncorporatedInventors: Patrick R. Gruber, Jeffrey J. Kolstad, Christopher M. Ryan, Eric S. Hall, Robin S. Eichen Conn
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Patent number: 5475063Abstract: Polymer blends of glycolide and/or lactide homopolymer and/or glycolide/lactide copolymer and polycaprolactone and/or polytrimethylene carbonate homopolymer or copolymers thereof and absorbable surgical devices manufactured therefrom having improved mechanical properties, such as improved impact resistance and improved cyclic flex, are disclosed. The blends may be prepared by polymerizing a glycolide or lactide containing polymer in the presence of a polymer derived from trimethylene carbonate or .epsilon.-caprolactone.Type: GrantFiled: December 14, 1994Date of Patent: December 12, 1995Assignee: United States Surgical CorporationInventors: Donald S. Kaplan, Matthew Hermes, Ross R. Muth, John Kennedy
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Patent number: 5472818Abstract: Spherical resin particles having a sharp particle size distribution and a method for producing such particles are disclosed. Resin particles according to this invention contain at least a polyester polymer and a polymer formed from a polymerizable monomer, and have an average diameter (D) of 1 to 500 .mu.m. At least 70% by weight of the particles have a diameter in the range of 0.5 D to 2.0 D. Such resin particles can be produced by swelling polyester-containing seed particles with a polymerizable monomer and then polymerizing the polymerizable monomer in swelled seed particles.Type: GrantFiled: October 6, 1994Date of Patent: December 5, 1995Assignee: Toyo Boseki Kabushiki KaishaInventors: Yasunari Hotta, Satoshi Maeda, Yozo Yamada, Shinichiro Mori, Toshio Tanaka, Koji Tanaka, Hiroshi Ono
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Patent number: 5470944Abstract: A degradable high molecular weight poly(lactic acid). A poly(lactic acid) has a terminal end group of one of carboxyl or hydroxyl groups with low molecular weight poly(lactic acid) units coupled with linking agents of di-isocyanates, bis-epoxides, bis-oxazolines and bis-ortho esters. The resulting high molecular weight poly(lactic acid) can be used for applications taking advantage of the improved physical properties.Type: GrantFiled: February 13, 1992Date of Patent: November 28, 1995Assignee: ARCH Development CorporationInventor: Patrick V. Bonsignore
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Patent number: 5468253Abstract: Medical devices or components for medical devices formed from bioabsorbable elastomers comprising a random copolymer are disclosed. The random copolymer is a copolymer of from about 30 to about 70 weight percent of: a) .epsilon.-caprolactone, trimethylene carbonate, an ether lactone, or a mixture of these, and b) the balance being substantially glycolide, para-dioxanone, or a mixture of these. The random copolymers surprisingly exhibit elastomeric properties, and the copolymers are bioabsorbable. The combination of physical and biological properties of these elastomeric copolymers are particularly well-suited for numerous medical and surgical applications.Type: GrantFiled: January 21, 1993Date of Patent: November 21, 1995Assignee: Ethicon, Inc.Inventors: Rao S. Bezwada, Angelo G. Scopelianos
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Patent number: 5466444Abstract: The invention relates to the use of copolymers of racemic lactide and .epsilon.-caprolactone, .delta.-valerolactone, gamma-decalactone or .beta.-hydroxybutyric acid, prepared by the reaction of the monomers in the molar ratio of lactide to reaction partner of approximately 95-70 to 5-30, with the addition of metal carboxylates, known per se, as initiators at temperatures of approximately 150.degree. C. over a period of time of approximately 16 to 18 hours, for the topical treatment of human or animal skin.Type: GrantFiled: June 29, 1992Date of Patent: November 14, 1995Inventor: Christian Jurgens
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Patent number: 5457144Abstract: This invention provides hydrolytically labile polyamide compositions and articles containing an ester derived moiety in the polymer backbone which will degrade after exposure to water over long periods of time.Type: GrantFiled: February 2, 1994Date of Patent: October 10, 1995Assignee: Rohm and Haas CompanyInventors: Norman L. Holy, Newman M. Bortnick
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Patent number: 5446123Abstract: A lactide polymer composition combining compositional and purity limitations and catalyst optimization or addition of stabilizing agents resulting in a melt-stable polymer is disclosed. The melt-stable lactide polymer comprises a plurality of polylactide polymer chains, residual lactide in concentration of less than 2 percent and water in concentration of less than 1000 parts-per-million. A stabilizing agent in an amount sufficient to reduce depolymerization of the lactide polymer during melt-processing or alternatively, control of catalyst level at a molar ratio of monomer to catalyst greater than 3000:1 is also included in the melt-stable composition. A process for manufacture of a melt-stable lactide polymer composition includes polymerizing a lactide mixture and adding stabilizing agents sufficient to reduce depolymerization of the polylactide during melt-processing, followed by devolatilizing the polylactide to remove monomer and water.Type: GrantFiled: April 25, 1994Date of Patent: August 29, 1995Assignee: Cargill, IncorporatedInventors: Patrick R. Gruber, Jeffrey J. Kolstad, Eric S. Hall, Robin S. Eichen Conn, Christopher M. Ryan
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Patent number: 5442032Abstract: This invention provides various copolymers comprising a repeating unit of the chemical formula:(CH.sub.2 CH.sub.2 CH.sub.2 OCH.sub.2 CO.sub.2)and other repeating units having a chemical formula selected from the group consisting of:(CHRCO.sub.2),([CH.sub.2 ].sub.5 CO.sub.2),(CH.sub.2 CH.sub.2 OCH.sub.2 CO.sub.2),(CH.sub.2 CH.sub.2 CH.sub.2 OCO.sub.2), andcombinations of two or mope thereof wherein R is a hydrogen atom or a methyl group and the first repeating unit is less than 45 weight percent of the total weight of the copolymer. This invention also relates to use of these copolymers in the fabrication of absorbable surgical devices such as sutures and as coatings for medical devices.Type: GrantFiled: March 15, 1994Date of Patent: August 15, 1995Assignee: Ethicon, Inc.Inventors: Steven C. Arnold, Rao S. Bezwada, Alastair W. Hunter
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Patent number: 5442033Abstract: A copolymer of from in the range of from about 55 to about 70 weight percent lactide and from in the range of from about 45 to about 30 mole percent .epsilon.-caprolactone suitable for use in biomedical applications such as drug delivery, coatings for surgical sutures and needles, and lubricants for medical devices.Type: GrantFiled: November 14, 1994Date of Patent: August 15, 1995Assignee: Ethicon, Inc.Inventor: Rao S. Bezwada
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Patent number: 5442016Abstract: This invention relates to materials for medical or veterinary use that possess considerably improved properties with regard to friction. The invention also relates to the production of such materials from existing materials that possess suitable bulk properties, but inappropriate frictional properties. This invention also relates to a hydrophilic coating material that provides improved frictional properties.Type: GrantFiled: April 20, 1994Date of Patent: August 15, 1995Assignee: American Cyanamid CompanyInventors: Peter K. Jarrett, George Jessup, Louis Rosati, Chris Martin, John W. Maney
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Patent number: 5439985Abstract: A biodegradable and hydrodegradable diblock copolymer includes a naturally-occurring poly(.beta.-alkanoate) component and a chemically synthesized polyester component formed by ring-opening polymerization. A method of forming the biodegradable and hydrodegradable diblock copolymer having a poly(.beta.-hydroxyalkanoate) component and a chemically synthesized polyester component includes exposing a naturally-occurring poly(.beta.-hydroxyalkanoate) to alcoholysis and then to a trialkyl metal to form a dialkyl metal poly(.beta.-hydroxyalkanoate) macroinitiator. The macroinitiator is then reacted with a lactone or lactide reactant to form the biodegradable and hydrodegradable diblock copolymer.Type: GrantFiled: July 28, 1993Date of Patent: August 8, 1995Assignee: University of Massachusetts LowellInventors: Richard A. Gross, Stephen P. McCarthy, Michael S. Reeve
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Patent number: 5440007Abstract: High molecular weight, biodegradable polymers of substituted-poly(.beta.-propioesters), wherein the repeat unit sequences have a predominantly syndiotactic arrangement and a method of forming such polymers are disclosed. The method includes exposing a substituted-.beta.-propiolactone to a tin-based organometallic catalyst for a sufficient combination of time and temperature to form the predominantly syndiotactic substituted-poly(.beta.-propioester).Type: GrantFiled: April 25, 1994Date of Patent: August 8, 1995Assignee: University of Massachusetts LowellInventors: Richard A. Gross, John E. Kemnitzer, Stephen P. McCarthy
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Patent number: 5434242Abstract: The invention relates to resorbable homopolymers and copolymers which are substantially free from polymerization catalysts and processes for preparing them.Type: GrantFiled: December 12, 1994Date of Patent: July 18, 1995Assignee: Boehringer Ingelheim GmbHInventors: Dieter Bendix, Gunther Entenmann
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Patent number: 5434241Abstract: This specification provides a biodegradable poly(lactic acid) of a star-shaped structure having a high molecular weight of more than 30,000 with excellent tensile strength and a process for its preparation which comprises direct polycondensation of lactic acid using polyhydroxyl compound having at least four hydroxyl groups.Type: GrantFiled: December 22, 1993Date of Patent: July 18, 1995Assignee: Korea Institute of Science and TechnologyInventors: Young H. Kim, Kwang D. Ahn, Yang K. Han, Soo H. Kim, Jeong B. Kim
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Patent number: 5431679Abstract: Block copolymers wherein one of the blocks is made from hard phase forming monomers and another of the blocks is made from soft phase forming monomers copolymerized with randomly intermingled units of other soft phase forming monomers. The copolymers are useful in forming surgical articles, including both monofilament and multifilament sutures.Type: GrantFiled: March 10, 1994Date of Patent: July 11, 1995Assignee: United States Surgical CorporationInventors: Steven L. Bennett, Cheng-Kung Liu
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Patent number: 5424346Abstract: The biodegradable polymer comprises polymerized lactic acid units of the structure: ##STR1## where n is an integer between 450 and 10,000 and the alpha carbon is a mixture of L- and D-configurations with a preponderance of either D- or L-units, wherein the polymer is suitable for replacement of polystyrene; the biodegradable composition also comprises blends of a physical mixture of polymerized lactic acid units of the formula I, where n is an integer between 450 and 10,000 and the alpha carbon is a mixture of L- and D-configurations with a preponderance of either D- or L-units, and a homopolymer of poly(D-lactic acid) or poly(L-lactic acid), and plasticizers that provide unique properties when intimately dispersed.Type: GrantFiled: May 9, 1994Date of Patent: June 13, 1995Assignee: Ecopol, LLCInventor: Richard G. Sinclair
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Patent number: 5420212Abstract: This invention relates to a polymer blend comprising:(a) a concentrate comprising a polycarbonate resin, polycaprolactone and a copolyester having repeat units derived from terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol; and(b) a copolyester having repeat units derived from terephthalic acid, ethylene glycol and 1,4-cyclohexanedimethanol.Type: GrantFiled: March 31, 1994Date of Patent: May 30, 1995Assignee: Eastman Chemical CompanyInventor: Ronald R. Light
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Patent number: 5410016Abstract: Hydrogels of polymerized and crosslinked macromers comprising hydrophilic oligomers having biodegradable monomeric or oligomeric extensions, which biodegradable extensions are terminated on free ends with end cap monomers or oligomers capable of polymerization and cross linking are described. The hydrophilic core itself may be degradable, thus combining the core and extension functions. Macromers are polymerized using free radical initiators under the influence of long wavelength ultraviolet light, visible light excitation or thermal energy. Biodegradation occurs at the linkages within the extension oligomers and results in fragments which are non-toxic and easily removed from the body. Preferred applications for the hydrogels include prevention of adhesion formation after surgical procedures, controlled release of drugs and other bioactive species, temporary protection or separation of tissue surfaces, adhering of sealing tissues together, and preventing the attachment of cells to tissue surfaces.Type: GrantFiled: March 1, 1993Date of Patent: April 25, 1995Assignee: Board of Regents, The University of Texas SystemInventors: Jeffrey A. Hubbell, Chandrashekhar P. Pathak, Amarpreet S. Sawhney, Neil P. Desai, Jennifer L. Hill
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Patent number: 5403897Abstract: A process for producing a lactic acid-based copolyester by the ring-opening copolymerization and transesterification of a lactide (A) with an aromatic polyester (B) and/or an aliphatic polyester (C) in the presence of a ring-opening polymerization catalyst (D), and a packaging material comprising the lactic acid-based copolyester obtained by the process are disclosed. According to the present invention, a lactic acid-based degradable copolyester which has a sufficiently high molecular weight and satisfactory toughness and also has suitable rigidity, pliability, and transparency according to applications can be produced. Further, a general-purpose packaging material, e.g., a sheet or film, which comprises the lactic acid-based copolyester produced by the process and is excellent in formability, degradability, and transparency can also be produced.Type: GrantFiled: March 25, 1994Date of Patent: April 4, 1995Assignee: Dainippon Ink & Chemicals, Inc.Inventors: Hiroshi Ebato, Satoshi Oya, Yasutoshi Kakizawa, Hideyuki Furuta, Kosuke Arai
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Patent number: 5403347Abstract: Block copolymers wherein one of the blocks is made from hard phase forming monomers and another of the blocks is made from soft phase forming monomers copolymerized with randomly intermingled units of other soft phase forming monomers. The copolymers are useful in forming surgical articles, including both monofilament and multifilament sutures. The block copolymer preferably comprising:a) a proportion of glycolic acid ester units as end blocks, andb) a center block comprising 1,4 dioxan-2-one randomly polymerized with 1,3 dioxane-2-one.Type: GrantFiled: March 2, 1994Date of Patent: April 4, 1995Assignee: United States Surgical CorporationInventors: Mark S. Roby, Steven L. Bennett, Cheng-Kung Liu
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Patent number: 5401778Abstract: A biodegradable plastic composition for forming biodegradable shaped bodies which includes a poly-.beta.-hydroxybutyrate having a viscosity of n.sub.A at 185.degree. C. and a polycaprolactone having a viscosity of n.sub.B at 185.degree. C., wherein the poly-.beta.-hydroxybutyrate is present in an amount C.sub.A of 10-45 or 55-85% by weight based on the total weight of the poly-.beta.-hydroxybutyrate and the polycaprolactone, and wherein n.sub.A, n.sub.B and C.sub.A satisfy the following condition:4.times.10.sup.-3 .times.C.sub.A -1.7.ltoreq.log (n.sub.A /n.sub.B).ltoreq.4.times.10.sup.-3 .times.C.sub.A -1.3.Type: GrantFiled: April 7, 1993Date of Patent: March 28, 1995Assignees: Director-General of Agency of Industrial Science and Technology, Mitsubishi Gas Chemical Co., Ltd.Inventors: Yutaka Tokiwa, Akira Iwamoto, Masahiro Harada, Shigeki Imagawa, Teizi Urakami
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Patent number: 5399666Abstract: Star-block copolymers containing polycaprolactone and polylactide blocks of limited molecular weight are tough, easily degradable polymers. Such copolymers, which are noncrystalline and have glass transition temperatures near or below room temperature, are useful in many packaging and other applications.Type: GrantFiled: April 21, 1994Date of Patent: March 21, 1995Assignee: E. I. Du Pont de Nemours and CompanyInventor: Thomas M. Ford
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Patent number: 5391707Abstract: Processes of producing 1,4-dioxan-2-one (p-dioxanone) are improved by the addition of a blocking agent to a crude reaction product containing p-dioxanone. The blocking agent reacts with unreacted starting materials in the crude reaction product to protect the active sites thereon with groups that do not initiate polymerization of p-dioxanone. The polymerization of p-dioxanone before its recovery from the process is thereby inhibited.Type: GrantFiled: December 10, 1993Date of Patent: February 21, 1995Assignee: United States Surgical CorporationInventor: Ying Jiang
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Patent number: 5382636Abstract: An internally plasticized vinyl chloride polymer with a polycaprolactone content ranging from 32 to 40% is prepared by polymerizing vinyl chloride in the presence of polycaprolactone. The graft copolymers show good transparency, homogeneity, and processing properties.The copolymers of the present invention can be used to produce materials used in medical applications, such as, blood bags and dialysis tubing.Type: GrantFiled: August 12, 1993Date of Patent: January 17, 1995Assignee: Huels AktiengesellschaftInventors: Frank Schmidt, Neidhard Gardiewski
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Patent number: 5382624Abstract: Spherical resin particles having a sharp particle size distribution and a method for producing such particles are disclosed. Resin particles according to this invention contain at least a polyester polymer and a polymer formed from a polymerizable monomer, and have an average diameter (D) of 1 to 500 .mu.m. At least 70% by weight of the particles have a diameter in the range of 0.5 D to 2.0 D. Such resin particles can be produced by swelling polyester-containing seed particles with a polymerizable monomer and then polymerizing the polymerizable monomer in swelled seed particles.Type: GrantFiled: September 10, 1993Date of Patent: January 17, 1995Assignee: Toyo Boseki Kabushiki KaishaInventors: Yasunari Hotta, Satoshi Maeda, Yozo Yamada, Shinichiro Mori, Toshio Tanaka, Koji Tanaka, Hiroshi Ono
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Patent number: 5376102Abstract: A deformable surgical repair device is manufactured from a block or graft copolymer. The copolymer comprises a plurality of first linkages selected from the group consisting of glycolic acid ester and lactic acid ester linkages, and mixtures thereof, and a plurality of second linkages selected from the group consisting of 1,3-dioxan-2-one; 1,4-dioxan-2-one and .epsilon.-caprolactone linkages. The plurality of first linkages comprises at least about 50 up to about 90 mole percent of the copolymer. In an alternative Claim, the deformable surgical repair device is manufactured from a blend of a first and a second absorbable polymer. The first absorbable polymer comprises a plurality of linkages selected from the group consisting of glycolic acid ester and lactic acid ester linkages, and mixtures thereof. The second absorbable polymer comprises a plurality of linkages selected from the group consisting of 1,3-dioxan-2-one; 1,4-dioxan-2-one and .epsilon.-caprolactone linkages.Type: GrantFiled: January 13, 1992Date of Patent: December 27, 1994Assignee: American Cyanamid Co.Inventors: Peter K. Jarrett, Donald J. Casey
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Patent number: 5360892Abstract: A water and UV light degradable copolymer of monomers of lactic acid and a modifying monomer selected from the class consisting of ethylene and polyethylene glycols, propylene and polypropylene glycols, P-dioxanone, 1,5 dioxepan-2-one, 1,4 -oxathialan-2-one, 1,4-dioxide and mixtures thereof. These copolymers are useful for waste disposal and agricultural purposes. Also disclosed is a water degradable blend of polylactic acid or modified polylactic acid and high molecular weight polyethylene oxide wherein the high molecular weight polyethylene oxide is present in the range of from about 2% by weight to about 50% by weight, suitable for films. A method of applying an active material selected from the class of seeds, seedlings, pesticides, herbicides, fertilizers and mixtures thereof to an agricultural site is also disclosed.Type: GrantFiled: August 5, 1993Date of Patent: November 1, 1994Assignee: Arch Development CorporationInventors: Patrick V. Bonsignore, Robert D. Coleman
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Patent number: 5359027Abstract: Polymers and copolymers of L(+) and D(-) lactic acid, with high molecular weight and in the absence of catalysts, are prepared by upgrading low molecular weight polymers in the solid state.Type: GrantFiled: September 30, 1993Date of Patent: October 25, 1994Assignee: Himont IncorporatedInventors: Gabriele Perego, Enrico Albizzati
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Patent number: 5359026Abstract: A copolymerized poly(lactide) polymer. A lactide is copolymerized with an epoxidized fat, oil, or mixture thereof thereby resulting in poly(lactide) copolymers having improved processing properties over prior poly(lactide)s.Type: GrantFiled: July 30, 1993Date of Patent: October 25, 1994Assignee: Cargill, IncorporatedInventor: Patrick R. Gruber
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Patent number: 5357035Abstract: A process for the continuous production of polylactide polymers from lactic acid which incorporates removal of water or a solvent carrier to concentrate the lactic acid feed followed by polymerization to a low-molecular-weight prepolymer. This prepolymer is fed to a reactor in which a catalyst is added to facilitate generation of lactide, the depolymerization product of polylactic acid. The lactide generated is continuously fed to a distillation system as a liquid or vapor wherein water and other impurities are removed. The resultant purified liquid lactide is fed directly to a polymerization process.Type: GrantFiled: September 16, 1993Date of Patent: October 18, 1994Assignee: Cargill, IncorporatedInventors: Patrick R. Gruber, Eric S. Hall, Jeffrey J. Kolstad, Matthew L. Iwen, Richard D. Benson, Ronald L. Borchardt