One of the patented technologies of polylactic acid layered plates

Polylactic acid (PLA) is a new type of polyester material produced by using organic acid lactic acid as a raw material. Polylactic acid has good biodegradability, can be completely degraded by microorganisms in the natural world after use, does not pollute the environment, and has advantages over existing plastic poly The advantages of ethylene, polypropylene, polystyrene and other materials are defined by the industry as the most promising new packaging materials in the new century, and are a star of environmental protection packaging materials. In the future, they will be expected to replace polyethylene, polypropylene, and polyphenylene. Ethylene and other materials are used in plastic products and have broad application prospects.

Polylactic acid has good mechanical properties and physical properties, suitable for blow molding, thermoplastics and other processing methods, processing is convenient, application is very extensive. It can be used to process various plastic products from industrial to civilian use, packaged foods, fast food lunch boxes, non-woven fabrics, industrial and civilian cloths, and can also be processed into agricultural fabrics, health fabrics, rags, hygiene products, outdoor UV protection fabrics, tent fabrics The market outlook is very promising.

At present, China's research on polylactic acid and related product development has just started. This series of articles will specifically analyze the foreign patents of polylactic acid in the application of plates and sheets to provide technical reference for relevant research institutions and enterprises in China.

In the patent database of DERWENT and the U.S. patent database, the author retrieved a total of 74 patent documents on the application of polylactic acid in layered products. One, two, and three of this series of articles will successively introduce that DERWENT is publicly available from January to October in 2005. Polylactic acid layered plate related patented technology:

1. Title: POLYLACTIC-ACID-baseD SHEET MATERIAL AND METHOD OF MAKING (polylactic acid sheet and its preparation method)

Source: US20050112352 (public date: 2005.05.26, filing date: 2003.11.26)

Inventors: Aylward Peter T (US); Best Kenneth W JR (US); Campbell Bruce C (US); Dagan Sandra J (US); Laney Thomas M (US)

The purpose of this patent is to provide a single or multi-layer sheet comprising a microporous layer which is permeable to a low surface tension liquid, the microporous layer comprising a continuous phase, consisting of a polylactic acid based material and interconnected micropores. The total absorption capacity of the microporous layer is at least 14 cc/m2.

The method for preparing a polylactic acid sheet disclosed in the present invention is: (a) mixing inorganic particles and melting polylactic acid material, (b) extruding a polylactic acid material containing inorganic particles to form a sheet, (c) a two-phase stretched sheet Interconnected micropores are formed around the inorganic particles, and the stretching temperature is lower than 75°C. The polylactic acid-based material is composed of polylactic acid and a compatible comonomer hydroxycarboxylic acid, wherein the polylactic acid is at least 75 wt%; the average particle diameter of the inorganic particles is 0.1-10 μm, which is 45-total weight of the microporous layer. At 75%, the inorganic particles can be selected from barium sulfate, calcium carbonate, zinc sulfide, zinc oxide, titanium dioxide, silica, alumina and their compounds.

Uses: This invention can be used for inkjet printer recording elements or other media.

2. Title: BIODEGRADABLE POLYESTER RESIN COMPOSITION AND FILMS, SHEETS AND OTHER MOLDED ARTICLES THEREOF (Biodegradable Polyester Resin Components and Their Films, Sheets, and Other Molded Products)

Source: US20040024141A1 (public date: 2004.02.05, filing date: 2003.06.27)

Inventor: Hasebe Tadashi (JP); Sashida Kazuyuki (JP)

Family patents: EP1388562(A1), JP2004067801(A)

The object of the present invention is to provide a transparent, biodegradable polyester resin composition and its films, sheets and other molded products having excellent antistatic properties.

The biodegradable polyester resin composition of the invention comprises: 0.2 to 5 parts by weight of an antistatic agent comprising mono fatty acid ester and alkyl sulfonate; and 100 parts by weight of a biodegradable polyester resin. Among them, the polyester resin is polylactic acid resin or the resin mainly includes polylactic acid.

3. Title: BIODEGRADABLE PACKAGING LAMINATE, A METHOD OF PRODUCING THE PACKAGING LAMINATE, AND PACKAGING ConTAINERS PRODUCED FROM THE PACKAGING LAMINAT (Biodegradable Packaging Laminate and Methods of Making Same, and Packaging Containers Made Therefrom)

Source: US20020127358 A1 (public day: 2002.09.12, filing date: 1999.05.21)

Inventor: BERLIN MIKAEL (SE); HENNINGSSON KARIN (SE)

Family patents: WO9809812 (A1), EP0927101 (A1), SE9603211 (L), SE514845 (C2)

The object of the invention is to provide a biodegradable packaging laminate with excellent liquid tightness and oxygen barrier properties.

The packaging laminate includes at least one liquid tight layer and an oxygen barrier layer, all of which are biodegradable. The liquid tight layer includes a copolymer and a homopolymer selected from the group consisting of lactic acid, glycol acid, lactide, glycolide, hydroxybutyric acid, hydroxyvaleric acid, hydroxycaproic acid, and pentane. The ester, the liquid tight layer is preferably the lactide copolymer and the homopolymer; the oxygen barrier layer employs a polymer selected from the group consisting of polyvinyl alcohol, starch and starch derivatives.

The biodegradable laminate is suitable for liquid food packaging.

4. Topic: ALIPHATIC POLYESTER COMPOSITIONS, FILMS MADE THEREOF AND

LAMINATES THEREOF (aliphatic polyester components and films and laminates made therefrom)

Source: US 6521336 B2 (Licensing Date: 2003.02.18, Filing Date: 2001.09.25)

Patentee: Tohcello Co Ltd JP

The purpose of the invention is to provide a biodegradable, transparent, aliphatic polyester component with excellent heat sealing at low temperature; to provide an aliphatic polyester film suitable for any molding method; to provide a good The heat seal strength, peel performance, laminates with excellent adhesion between layers.

The disclosed aliphatic polyester component comprises (by weight): 27-70% polylactic acid, 70-27% aliphatic polyester, and 1-20% tackifier, 3-10% tackifier selected from fats Group ring hydrocarbon resins, rosin ester salts, and rosin esters with an acid number of ≤10. The laminate includes a substrate and an aliphatic polyester component disposed thereon, the substrate being a biodegradable polymer, which may be paper.

5. Title: LACTIC ACID-baseD POLYMER LAMINATED PRODUCT AND MOLDED PRODUCT

Source: US 6248430 B1 (Licensing Announcement Date: 2001.06.19, Filing Date: 1999.08.10)

Patentee: Dainippon Ink & Chemicals Inc (JP)

The invention relates to a lactic acid polymer layered product with accelerated or controlled biodegradability, which can be used as a film or sheet for agriculture or civil engineering, or used for packaging various foods, beverages, chemicals, and sundries. Etc., also relates to molded articles prepared from the layered products, particularly films, sheets, packaging bags, or lightweight containers, injection molded containers, blow molded containers, and the like obtained by heat molding from a film or sheet.

An object of the present invention is to provide a lactic acid-based polymer layered product in which there is little leakage of lactide during storage of molded or molded articles, and a degradation rate is high, and a molded product obtained therefrom.

The independent claim of the invention is a lactic acid-based polymer layered product comprising (I) a degradation accelerator barrier layer prepared from a lactic acid based polymer (B), the polymer (B) containing not more than 0.1 (wt %) of the lactide is laminated on one or both sides of the base layer (II), the base layer (II) is made of the lactic acid base polymer (A), and the polymer (A) includes a degradation accelerator made of lactide and / Or content of 0.3-7 (wt)% of organic acids, wherein the ratio of the thickness of the barrier layer and the base layer is 0.02:1.

6. Title: HEAT-SEALABLE LACTIC ACID-baseD POLYMER LAMINATES (heat-sealable lactic acid-based polymer laminates)

Source: US 6153276 A (Licensing Date: 2000.11.28, Filing Date: 1998.05.21)

Patentee: Dainippon Ink & Chemicals Inc JP

The object of the invention is to provide a lactic acid-based polymer laminate having heat resistance higher than 60°C, high heat-sealing strength and good biodegradability, which can be used in various films, sheets, packaging containers, etc., and is mainly applicable to Packaging of various foods, beverages, pharmaceuticals, sundries, etc., as well as packaging containers such as bags, boxes, and lightweight containers that are thermoformed from laminates.

The independent claim of the invention is a heat-sealable lactic acid-based polymer laminate comprising: a base layer (I) made of a crystalline lactic acid base polymer (A) having a melting point of at least 120[deg.] C., and a softening point of 40. A heat-seal layer (II) made of an amorphous lactic acid-based polymer at -110°C, wherein one side of the heat seal layer is laminated on one side of the base layer, and the other side of the heat seal layer is the outer surface of the laminate layer.