Biodegradable polymer films and sheets suitable for use as laminates and wraps for laminates and other packaging materials

Patent Name Suitable Biodegradable Polymer Films and Films for Laminate Covers and Wraps and Other Packaging Materials Patent Applicant E. Kashangji Industrial Co., Ltd. Principal Applicant Address California State Inventor Kischan Kemani Harald Schmidt's application (patent) No. 01814532.9 Application date 2001.03.28 Award date Approval notice No. 1468273 Approval announcement date 2004.01.14 Instruction CD D0402 Main classification number C08G63/91 C08G63/91; C08L3 /00; B32B27/06 Division Original Application Number PRIORITY SUMMARY Abstract This invention discloses a biodegradable polymer blend comprising at least one "hard" biopolymer and at least one "soft" polymer. Made of polymer, suitable for laminate coverings, wraps and other packaging materials. "Hard" biopolymers tend to be more brittle and more rigid, and typically have a glass transition temperature above about 10°C. "Soft" biopolymers tend to be softer and more flexible, and typically have a glass transition temperature below about 0°C. Although hard and soft polymers each have specific intrinsic advantages, it has been found that specific blends of hard and soft polymers have superior synergistic properties than hard or soft polymers per se. Biodegradable polymers include polyesters, polyesteramides, and thermoplastically processable starches. The polymer blend may optionally contain inorganic fillers. Films and sheets made from this polymer blend can be textured to enhance their rich feel. Wraps are usually manufactured to have good "deadfold" properties, so as to maintain the package site and do not bounce back to the "unwrapped" and planar form. When laminated films are evaluated in terms of water vapor permeability coefficient (WVPC), they generally have good water vapor barrier properties. Slaves 1. A biodegradable polymer blend comprising: at least one rigid, biodegradable synthetic polymer having a glass transition temperature above about 10°C; and at least one having less than about A soft, biodegradable polymer having a glass transition temperature of 0°C, wherein the polymer blend is suitable for molding into at least one of an extruded sheet and a blown film.