Patents Assigned to Landec Corporation
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Patent number: 7175832Abstract: Aqueous dispersions of crystalline polymers based on hydrophobic monomers, preferably on a mixture of hydrophobic and hydrophilic monomers which contains a crosslinking monomer, particularly side chain crystalline (SCC) polymers. The dispersions are useful for providing coatings on substrates, particularly on seeds (whose dormancy is thus extended) and on fibrous substrates, particularly human hair (which thus becomes heat-settable).Type: GrantFiled: December 17, 2002Date of Patent: February 13, 2007Assignee: Landec CorporationInventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
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Patent number: 7169451Abstract: Novel gas-permeable membranes which are particularly useful in the packaging of fresh cut fruit and vegetables, and other respiring biological materials. The membranes have an O2 permeability of at least 775,000 ml/m2.atm.24 hrs, a P10 ratio of at least 1.3, and a ratio of CO2 permeability to O2 permeability (R) of at least 1.5, and are made by forming thin polymeric coatings on microporous polymeric films. Preferred coating polymers are side chain crystalline polymers. Preferred microporous films contain inorganic fillers, particularly such films based on ultrahigh molecular weight polyethylene or polypropylene. FIG. 1 illustrates how O2 permeability and R ratio vary for different coating polymers and microporous films.Type: GrantFiled: October 12, 2001Date of Patent: January 30, 2007Assignee: Landec CorporationInventors: Raymond Clarke, Ray F. Stewart, Valentine Y. Yoon, Donald A. Schultz, Bradley McClary
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Patent number: 7101928Abstract: Novel thickeners for oil-containing compositions are crystalline polymers, preferably side chain crystalline polymers, which (a) have a crystalline melting point, Tp, and an onset of melting temperature, To, such that Tp?To is less than Tp0.7; (b) are soluble in the oil at temperatures above Tp, and (c) have been dispersed in the oil by a process which comprises (i)dissolving the polymer in the oil at a temperature above Tp, and (ii) cooling the solution from step (i) to crystallize the polymer in the oil.Type: GrantFiled: September 17, 1999Date of Patent: September 5, 2006Assignee: Landec CorporationInventor: Steven P. Bitler
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Patent number: 6989417Abstract: Thickeners for oil-containing compositions, particularly cosmetic and personal care compositions, are side chain crystalline polymers which are uniformly dispersed as a crystallized solid in the oil.Type: GrantFiled: March 16, 2001Date of Patent: January 24, 2006Assignee: Landec CorporationInventors: Steven P. Bitler, David D. Taft
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Patent number: 6831116Abstract: Novel modifying agents contain a sharply-melting crystalline polymer ingredient, preferably a side chain crystalline (SCC) ingredient, and an active chemical ingredient. Such modifying agents, especially when in the form of particles, can be placed in contact with a matrix, will not modify the matrix below the crystalline melting point Tp, but will rapidly modify the matrix above Tp. The active chemical ingredient can react with the matrix, catalyze a reaction of the matrix, or inhibit a reaction of the matrix. Particularly useful compositions are polymer precursors which are storage-stable at low temperatures but which are rapidly converted to crosslinked resins when heated to temperatures above Tp, optionally in the presence of light.Type: GrantFiled: December 8, 2000Date of Patent: December 14, 2004Assignee: Landec CorporationInventors: Steven P. Bitler, Ray F. Stewart, Mark A. Wanthal, David A. Kamp, Paul A. Meyers, David D. Taft, Donald A. Schultz
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Patent number: 6548132Abstract: Novel gas-permeable membranes which are particularly useful in the packaging of fresh cut fruit and vegetables, and other respiring biological materials. The membranes comprise a microporous film or other gas-permeable substrate and, coated on the substrate, a layer of a block copolymer having a heat of fusion of at least 5 J/g and containing polysiloxane polymeric blocks and crystalline polymeric blocks having a melting point of −5 to 40° C.Type: GrantFiled: July 23, 1998Date of Patent: April 15, 2003Assignee: Landec CorporationInventors: Raymond Clarke, Donald A. Schultz
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Patent number: 6544453Abstract: Shrinkage of cured resins is reduced by mixing the crosslinkable resin with a low profile additive (LPA). The LPA is in the form of particles which comprise an SCC polymer (or a similar crystalline polymer which melts over a narrow temperature range). The system is cured at a temperature above the melting point of the crystalline polymer (Tp), and the system and the LPA are such that at least part of the LPA remains as a separate phase in the curable resin at temperatures below Tp. It is believed that at least part of the crystalline polymer remains as a separate phase in the resin as it cures. Preferably at least part of the crystalline polymer forms a separate phase in the cured polymer after it has cooled.Type: GrantFiled: December 11, 2000Date of Patent: April 8, 2003Assignee: Landec CorporationInventors: David D. Taft, Steven P. Bitler
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Patent number: 6540984Abstract: Aqueous dispersions of crystalline polymers based on hydrophobic monomers, preferably on a mixture of hydrophobic and hydrophilic monomers which contains a crosslinking monomer, particularly side chain crystalline (SCC) polymers. The dispersions are useful for providing coatings on substrates, particularly on seeds (whose dormancy is thus extended) and on fibrous substrates, particularly human hair (which thus becomes heat-settable).Type: GrantFiled: January 18, 2001Date of Patent: April 1, 2003Assignee: Landec CorporationInventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
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Patent number: 6492462Abstract: The rheological properties of a crosslinkable resin system are modified by the presence of a side chain crystalline (SCC) polymer (or a similar crystalline polymer which melts over a narrow temperature range). The polymer dissolves in the curable system at temperatures above the melting point of the crystalline polymer (Tp), but when the system is then cooled to a temperature below Tp, at least partially forms a separate phase in the curable system. Below Tp, this separate phase substantially increases the viscosity of the curable system (i.e. makes it thicker than the same system without the crystalline polymer). This is particularly valuable for sheet molding composites (SMCs) in which the increase in viscosity makes the composites less tacky, and for dry film resists (DFRs). Above Tp, the curable system containing the dissolved crystalline polymer has a viscosity which is substantially less than its viscosity below Tp.Type: GrantFiled: December 19, 2000Date of Patent: December 10, 2002Assignee: Landec CorporationInventors: Steven P. Bitler, David D. Taft, Ray F. Stewart
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Patent number: 6376032Abstract: Novel gas-permeable membranes which are particularly useful in the packaging of fresh cut fruit and vegetables, and other respiring biological materials. The membranes have an O2 permeability of at least 775,000 ml/m2.atm.24 hrs, a P10 ratio of at least 1.3, and a ratio of CO2 permeability to O2 permeability (R) of at least 1.5, and are made by forming thin polymeric coatings on microporous polymeric films. Preferred coating polymers are side chain crystalline polymers. Preferred microporous films contain inorganic fillers, particularly such films based on ultrahigh molecular weight polyetheylene or polypropylene. FIG. 1 illustrates how O2 permeability an R ratio vary for different coating polymers and microporous films.Type: GrantFiled: December 5, 1996Date of Patent: April 23, 2002Assignee: Landec CorporationInventors: Raymond Clarke, Ray F. Stewart, Valentine Y. Yoon, Donald A. Schultz, Bradley McClary
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Patent number: 6255367Abstract: Novel modifying agents contain a sharply-melting crystalline polymer ingredient, preferably a side chain crystalline (SCC) ingredient, and an active chemical ingredient. Such modifying agents, especially when in the form of particles, can be placed in contact with a matrix, will not modify the mix below the crystalline melting point Tp, but will rapidly modify the matrix above Tp. The active chemical ingredient can react with the matrix, catalyze a reaction of the matrix, or inhibit a reaction of the matrix. Particularly useful compositions are polymer precursors which are storage-stable at low temperatures but which are rapidly converted to crosslinked resins when heated to temperatures above Tp, optionally in the presence of light.Type: GrantFiled: December 16, 1998Date of Patent: July 3, 2001Assignee: Landec CorporationInventors: Steven P. Bitler, Ray F. Stewart
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Patent number: 6224793Abstract: The invention is an encapsulated active agent comprising an active agent encapsulated in a crystallizable or thermoplastic polymer wherein the particle size of the encapsulated active agent is 3,000 microns or less wherein the active agent is not significantly extractable from the particles under ambient conditions. In another embodiment the invention is a process for preparing an encapsulated agent which comprises a) contacting an active agent with a crystallizable or thermoplastic polymer wherein the polymer is molten and the active agent in not volatile under the contacting conditions; b) forming particles of about 3000 microns or less; and c) exposing the particles to conditions such that the portion of the particle at and near the surface undergoes rapid solidification. The encapsulated active agents of the invention do not require washing in order for them to be stable in curable compositions. These encapsulated active agents can be designed to release the active agent at a desired temperature.Type: GrantFiled: April 27, 1999Date of Patent: May 1, 2001Assignees: The Dow Chemical Company, Landec CorporationInventors: Dwight K. Hoffman, Steven P. Bitler
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Patent number: 6210724Abstract: Sealed packages of foodstuffs which are biological materials, particularly fruit, are vented by a temperature-sensitive control unit. The control unit covers an aperture in a wall of the package. The control unit includes a barrier member which is secured over the aperture by a layer of temperature sensitive adhesive, and a force member which lifts the barrier member away from the aperture when an increase in temperature weakens the adhesive. The force member is preferably elastically deformed.Type: GrantFiled: August 23, 1999Date of Patent: April 3, 2001Assignee: Landec CorporationInventors: Raymond Clarke, Andrew W. Larson, Steven James
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Patent number: 6199318Abstract: Crystalline polymers are prepared as a latex, and are useful for coating fibrous materials such hair and fabrics. The latex can have a high solids content greater than 30%, a residual monomer content of less than 1%, and can be used for repeatedly setting fibrous materials into desired configurations. The latex is also useful for coating organisms such as seeds. The particulate coating extends the dormancy of the organism and/or protects the organism, and is easily shed by a germinating seed. The coating can contain a seed coating additive, such as a colorant or fungicide.Type: GrantFiled: September 15, 1997Date of Patent: March 13, 2001Assignee: Landec CorporationInventors: Ray F. Stewart, Natarajan Balachander, Steven P. Bitler, Loc Phan, Valentine Y. Yoon
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Patent number: 6060540Abstract: The present invention provides a modeling paste comprising a latent material which can be applied as a thick layer to a substrate and which after activation rapidly crosslinks to a machinable surface.Type: GrantFiled: February 13, 1998Date of Patent: May 9, 2000Assignee: Landec CorporationInventors: Mark A. Wanthal, Paul C. Paetzke, Guy J. Stokes
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Patent number: 6013293Abstract: Packaging of fruit and vegetables, and other respiring biological materials, makes use of an atmosphere-control member comprising a gas-permeable membrane and an apertured cover member over the membrane. The combination results in a control member having a ratio of CO.sub.2 transmission rate to O.sub.2 transmission rate which is lower than the same ratio for the gas-permeable membrane. This is particularly useful for materials which are preferably stored in an atmosphere containing a relatively high proportion of CO.sub.2.Type: GrantFiled: September 10, 1997Date of Patent: January 11, 2000Assignee: Landec CorporationInventor: Colette Pamela De Moor
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Patent number: 5783302Abstract: TPE's which comprise A blocks or B blocks or both A blocks and B blocks, which are crystalline and in which at least a part of the crystallinity result from the presence of crystallizable side chains. Such crystalline blocks are referred to as SCC blocks. TPE's containing SCC A blocks are novel and as such form part of the present invention. The invention also includes processes, compositions, shaped articles and assemblies which make use of TPE's containing SCC A blocks.Type: GrantFiled: May 22, 1995Date of Patent: July 21, 1998Assignee: Landec CorporationInventors: Steven P. Bitler, Raymond Clarke, David A. Kemp, Ray F. Stewart, Valentine Y. Yoon, Robert G. Freelin
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Patent number: 5752926Abstract: Orthopedic casts which comprise an elastically deformed support which is held in its elastically deformed state by a solid casting composition. After the cast has been placed around a patient's limb, it is heated to soften the casting composition, thus permitting recovery of the cast into conforming contact with the limb. The support can for example be a fabric knitted from elastomeric fibers and glass fiber yarns. The casting composition can for example comprise polycaprolactone and/or a side chain crystallizable polymer, which melts at 45.degree.-60.degree. C. A padded liner can be placed between the cast and the limb. Recovery of the cast is preferably carried out by means of a hot air gun.Type: GrantFiled: November 9, 1993Date of Patent: May 19, 1998Assignee: Landec CorporationInventors: Andrew W. Larson, Steven P. Bitler, Lawrence C. Greene, David D. Taft, Ray F. Stewart, Valentine Y. Yoon, Thomas W. Ross, David A. Kamp, Edward E. Schmitt
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Patent number: 5665822Abstract: Thermoplastic elastomers (TPEs) containing side chain crystalline (SCC) blocks. The SCC blocks my be hard (A) blocks or the soft (B) blocks (or both) in the TPE. Some of these TPEs are novel, e.g. those in which A blocks are SCC blocks, and the B blocks are polyethers, polyacrylates, polyamides, polyurethanes or polysiloxanes. The SCC-containing TPEs are particularly useful as matrix materials for other components which are dispersed therein, e.g. energetic solids and other thermally responsive materials.Type: GrantFiled: April 14, 1993Date of Patent: September 9, 1997Assignee: Landec CorporationInventors: Steven P. Bitler, Ray F. Stewart, David A. Kamp, Robert G. Freelin, Valentine Y. Yoon
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Patent number: 5469867Abstract: A method of blocking channels in a mammal which channels normally carry a material from one point to another is carried out by injecting a heated flowable polymer into the channel and allowing the polymer to cool and solidify, thus creating a plug or channel occluder. The plug can be later removed physically in its solid form or removed gradually by softening and/or fluidizing it by heating and/or chemical means. The channel occluder is preferably comprised of a main chain or side-chain crystallizable polymer but may be comprised of other polymers provided the polymers are formulated to have certain characteristics. The polymers must be solid and/or non-flowable at body temperature or lower and flowable when heated slightly above body temperature, i.e., 10 centigrade degrees or less above body temperature. The polymer is capable of changing quickly from a flowable state to a non-flowable state by moving through only a few centigrade degrees of temperature and is a non-immunogenic, biocompatible material.Type: GrantFiled: September 2, 1992Date of Patent: November 28, 1995Assignee: Landec CorporationInventor: Edward E. Schmitt