Compositions: coating or plastic – Coating or plastic compositions – Proteinaceous material containing
Reexamination Certificate
1998-03-05
2001-01-23
Mulcahy, Peter D. (Department: 1713)
Compositions: coating or plastic
Coating or plastic compositions
Proteinaceous material containing
C106S129100, C524S047000
Reexamination Certificate
active
06176915
ABSTRACT:
FIELD OF THE INVENTION
The invention relates, according to one embodiment, to new sorghum-based biodegradable formulations. Pursuant to another embodiment, the invention relates to new methods and processes for the manufacture of novel sorghum-based biodegradable formulations. According to a further embodiment, the invention relates to new biodegradable shaped articles manufactured utilizing: (1) the inventive sorghum-based formulations, and (2) the inventive methods and processes of the present invention.
BACKGROUND OF THE INVENTION
Biodegradable materials are presently in high demand for applications in packaging materials. Commonly used polystyrene (“Styrofoam” (Trademark)), polypropylene, polyethylene, and other non-biodegradable plastic-containing packaging materials are considered detrimental to the environment and may present health hazards. The use of such non-biodegradable materials will decrease as government restrictions discourage their use in packaging applications. Biodegradable materials that are flexible, pliable and non-brittle are needed in a variety of packaging applications, particularly for the manufacture of shaped biodegradable containers for food packaging.
For such applications, the biodegradable material must have mechanical properties that allow it to be formed into and hold the desired container shape, be resistant to collapsing, tearing or breaking.
Starch is an abundant, inexpensive biodegradable polymer. A variety of biodegradable based materials have been proposed for use in packaging applications. Conventional extrusion of these materials produces expanded products that are brittle, sensitive to water and unsuitable for preparation of packaging materials. Attempts to prepare biodegradable products with flexibility, pliability or resiliency and other mechanical properties acceptable for various biodegradable packaging applications have generally focused on chemical or physico-chemical modification of starch, the use of expensive high amylose starch or mixing starch with synthetic polymers to achieve the desired properties while retaining a degree of biodegradability. A number of references relate to extrusion and to injection molding of starch-containing compositions.
U.S. Pat. No. 5,160,368 discloses a biodegradable package for fast food comprising a heat-molded body of a moldable composition which consists essentially of an admixture of fully biodegradable natural materials comprising flour from edible gramineous plants, crushed gramineous hay, a minor proportion of preserving agents, and a plasticizing agent for providing a starting moldable dough suitable for being molded into the shaped fast food package. The patent discloses the flour may be derived from any edible gramineous plants including corn, wheat, and sorghum.
U.S. Pat. No. 5,288,318 discloses a method and composition for making biodegradable injection molded parts from 30% to 70% cellulose acetate, 10% to 60% unmodified raw (whole) starch, and 5% to 35% plasticizer including glycerols and glycerol acetates. Other ingredients that can be used include: starch, flour and paper acetates; gelatin; boric acid; and agricultural fillers. The solid ingredients are combined and fed to an extruder used to make pellets or to feed injection molding equipment. The resulting parts are clear to white or colorful depending upon the added filler materials. The plastics formed are water resistant, high strength and biodegradable. The starch source may be selected from the group consisting of corn, tapioca, potato, sago, wheat, rye, pea, sorghum, rice and arrowroot, and in embodiments where the starch is corn starch, the corn starch may contain between about 30% and 75% amylose.
U.S. Pat. Nos. 5,321,064 and 5,444,078 disclose a biodegradable interpolymer and composition prepared by the reactive blending of a synthetic polymer having functional groups with a naturally occurring biodegradable polymer such as a carbohydrate or protein compound. During reactive blending, the synthetic polymer is said to undergo a chemical reaction with the biodegradable natural polymer which results in covalent and physical bonding between the two polymers, thereby forming an interpolymer. By this process, a biodegradable interpolymer composition is produced that is suitable for molding various articles. It is disclosed that a variety of naturally occurring biodegradable materials can be employed in producing the biodegradable interpolymers and compositions. Such natural polymer materials disclosed include carbohydrates such as starch and cellulose, lignin, proteins, nucleic acids, amino acids, and lipids, which are all biodegradable. These natural polymers can be used either separately or in various mixtures in formulating the interpolymer and composition of the invention. The above natural polymers can be derived from corn, wheat, potato, sorghum, tapioca, rice, arrow root, sago, soybean, pea, sunflower, peanut, gelatin, milk, eggs, etc.
U.S. Pat. No. 5,397,834 provides biodegradable, thermoplastic compositions made of the reaction product of a starch aldehyde with protein. According to the disclosure, the resulting products formed with the compositions possess a smooth, shiny texture, and a high level of tensile strength, elongation, and water resistance compared to articles made from native starch and protein Suitable starches which may be modified and used according to the invention include those derived, for example, from corn including maize, waxy maize and high amylose corn; wheat including hard wheat, soft wheat and durum wheat; rice including waxy rice; and potato, rye, oat, barley, sorghum, millet, triticale, amaranth, and the like. The starch may be a normal starch (about 20-30 wt % amylose), a waxy starch (about 0-8 wt % amylose), or a high-amnylose starch (greater than about 50 wt % amylose).
U.S. Pat. Nos. 4,133,784, 4,337,181, 4,454,268, 5,322,866, 5,362,778, and 5,384,170 relate to starch-based films that are made by extrusion of destructurized or gelatinized starch combined with synthetic polymeric materials. U.S. Pat. No. 5,322,866 specifically concerns a method of manufacture of biodegradable starch-containing blown films that includes a step of extrusion of a mixture of raw unprocessed starch, copolymers including polyvinyl alcohol, a nucleating agent and a plasticizer. The process is said to avoid the need for pre-processing of the starch. U.S. Pat. No. 5,409,973 reports biodegradable compositions made by extrusion from destructurized starch and an ethylenevinyl acetate copolymer.
U.S. Pat. No. 5,087,650 relates to injection-molding of mixtures of graft polymers and starch to produce partially biodegradable products with acceptable elasticity and water stability.
U.S. Pat. No. 5,258,430 relates to the production of biodegradable articles from destructurized starch and chemically-modified polymers, including chemically-modified polyvinyl alcohol. The articles are said to have improved biodegradability, but to retain the mechanical properties of articles made from the polymer alone.
U.S. Pat. No. 5,292,782 relates to extruded or molded biodegradable articles prepared from mixtures of starch, a thermoplastic polymer and certain plasticizers.
U.S. Pat. No. 5,403,875 relates to blends of starch with acrylic polymers which are melt-processed into thermoplastic articles.
U.S. Pat. No. 5,393,804 relates to biodegradable compositions made from starch melts containing converted starch and plasticizers including polyvinyl alcohol.
U.S. Pat. No. 5,095,054 concerns methods of manufacturing shaped articles from a mixture of destructurized starch and a polymer.
U.S. Pat. No. 4,125,495 relates to a process for manufacture of meat trays from biodegradable starch compositions. Starch granules are chemically modified, for example with a silicone reagent, blended with polymer or copolymer and shaped to form a biodegradable shallow tray.
U.S. Pat. No. 4,673,438 relates to extrusion and injection molding of starch for the manufacture of capsules.
U.S. Pat. No. 5,427,614 also relates to a method of injection molding in w
Bittner Donald R.
Franke Hans G.
Baker & Botts L.L.P.
Mulcahy Peter D.
Standard Starch, L.L.C.
LandOfFree
Sorghum meal-based biodegradable formulations, shaped... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Sorghum meal-based biodegradable formulations, shaped..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Sorghum meal-based biodegradable formulations, shaped... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2451214