Abstract: Polylactide resins are blended with core-shell rubber particles to improve impact strength. A good balance of impact strength and transparency is achieved when the rubber particles are distributed within the polymer matrix such that most of them exist as single particles or agglomerates having a diameter of 150 nanometers or more, and the number average size of the particles and agglomerates is not more than 210 nanometers.
Type:
Grant
Filed:
October 18, 2007
Date of Patent:
May 22, 2012
Assignee:
NatureWorks LLC
Inventors:
Laura Mae Babcock, David E. Henton, Fasil A. Tadesse
Abstract: PLA stereocomplex fibers are made by separately melting a high-D PLA starting resin and a high-L starting resin, mixing the melts and spinning the molten mixture. Subsequent heat treatment introduces high-melting “stereocomplex” crystallinity into the fibers. The process can form fibers having a high content of “stereocomplex” crystallites that have a high melting temperature. As a result, the fibers have excellent thermal resistance. The process is also easily adaptable to commercial melt spinning operations.
Type:
Grant
Filed:
September 26, 2008
Date of Patent:
May 22, 2012
Assignee:
NatureWorks LLC
Inventors:
Robert A. Green, Chad Henry Kamann, Jeffrey John Kolstad
Abstract: Metal catalyst residues in resins containing polymerized lactic acid units, such as polylactides, are deactivated by treatment with a polymer or copolymer that contain pendant acid groups and pendant ester groups, with an acid-containing PLA resin, or with a polymer or copolymer having at least one acid groups per 250 atomic mass units and which has pendant lactic acid or poly(lactic acid) groups. The deactivating agent is effective at deactivating the catalyst, and has little effect on the optical clarity of the resin.
Abstract: This invention provides a process for extruding a PLA resin using high levels of CO2. Excellent quality, low density foam is produced easily and reproducibly. The foams arc capable of being heat-annealed to induce significant crystallinity, even when an ordinarily amorphous PLA resin is used.
Type:
Grant
Filed:
March 24, 2005
Date of Patent:
September 6, 2011
Assignee:
NatureWorks LLC
Inventors:
Kevin Cink, Jeffrey C. Smith, James F. Nangeroni, Jed Richard Randall
Abstract: Thermoformed PLA stereocomplex parts are made using a PLA stereocomplex composition having a highest crystallization melting temperature from 200 to 215° C. The stereocomplex composition preferably has less than 5 J/g of lower melting (160 to 190° C.) crystallites. The stereocomplex can be pre-annealed in various ways to reduce thermoforming cycle times. The stereocomplex forms parts with low haze and good thermal resistance, at reasonable cycle times.
Abstract: Amorphous sheets of PLA resins are thermoformed by heating the sheets until they become semicrystalline, and then forming the sheets on a relatively cold mold. Semicrystalline formed articles having improved heat resistance are made by the process.
Abstract: Polylactide polymers are reacted with an epoxy-functional acrylate polymer to introduce long-chain branching into the polymer. The acrylate polymer provides a flexible means for introducing a controllable amount of branching into the polylactide polymer, with little risk of forming gelled or highly crosslinked structures. The branched polylactide polymers have excellent melt rheological properties that make them more easily processable in various melt-processing applications.
Type:
Grant
Filed:
June 23, 2005
Date of Patent:
July 28, 2009
Assignee:
NatureWorks LLC
Inventors:
Jed Richard Randall, Kevin Cink, Jeffrey C. Smith
Abstract: Sugar mixtures containing nonfermentable oligomers are fermented in the presence of certain enzymes that depolymerise the oligomers simultaneously with the fermentation process.
Type:
Application
Filed:
March 16, 2005
Publication date:
January 8, 2009
Applicant:
NATUREWORKS LLC
Inventors:
Daniel R. Beacom, Jeffrey J. Kolstad, David H. Reeder, Brian J. Rush
Abstract: Containers are manufactured in an injection stretch molding process using a PLA resin having a specified ratio of lactic acid stereoisomers and stretch ratios. The process permits good quality containers to be made at good operating rates.
Type:
Application
Filed:
June 23, 2005
Publication date:
August 16, 2007
Applicant:
NATUREWORKS LLC
Inventors:
Kevin Cink, Richard Bopp, Kevin Sikkema
Abstract: Specific oxygen uptake (OUR) is used as a process control parameter in fermentation processes. OUR is determined during at least the production phase of a fermentation process, and process parameters are adjusted to maintain the OUR within desired ranges. The invention is particularly applicable when the fermentation is conducted using a microorganism having a natural PDC pathway that has been disrupted so that it no longer functions. Microorganisms of this sort often produce poorly under strictly anaerobic conditions. Microaeration controlled by monitoring OUR allows the performance of the microorganism to be optimized.
Type:
Grant
Filed:
May 30, 2003
Date of Patent:
June 19, 2007
Assignee:
NatureWorks LLC
Inventors:
Pim Van Hoek, Aristos Aristidou, Brian Rush
Abstract: The present invention relates to biocatalysts that are cells, optimally of the Crabtree-negative phenotype, comprising expression vectors encoding genes heterologous to the cell that enable increased production of organic products. More specifically, the invention relates to genetically modified Candida cells, methods for making the Candida cells, and their use in production of organic products, particularly lactic acid.
Type:
Application
Filed:
August 21, 2006
Publication date:
April 26, 2007
Applicant:
Natureworks LLC.
Inventors:
Vineet Rajgarhia, Merja Penttila, Laura Ruohonen, Marja Ilmen, Kari Koivuranta, Pirkko Suominen
Abstract: The present invention relates to biocatalysts that are cells, optimally of the Crabtree-negative phenotype, comprising expression vectors encoding genes heterologous to the cell that enable increased production of organic products. More specifically, the invention relates to genetically modified Candida cells, methods for making the Candida cells, and their use in production of organic products, particularly lactic acid.
Type:
Grant
Filed:
May 23, 2002
Date of Patent:
November 28, 2006
Assignee:
Natureworks LLC
Inventors:
Vineet Rajgarhia, Merja Penttilä, Laura Ruohonen, Marja Ilmén, Kari Koivuranta, Pirkko Suominen
Abstract: Copolymers having repeating units derived from monocyclic esters or carbonates and certain bicyclic diesters and/or carbonates have controllable rheological properties. The bicyclic diester and/or carbonate copolymerizes easily with the monocyclic monomers, especially with lactide, to form copolymer that can have tailored levels of branching. The copolymers have excellent rheological properties, including increased melt tensions and improved shear thinning, compared to the analogous linear polymers.
Type:
Grant
Filed:
December 1, 2003
Date of Patent:
March 21, 2006
Assignee:
Natureworks LLC
Inventors:
Ray Drumright, Mark Hartmann, Richard A. Wolf