Bio-degradable resin composition, film and shaped article

• US 6,146,750 A
• Filed: 09/22/1995
• Issued: 11/14/2000
• Est. Priority Date: 01/24/1994
• Status: Expired due to Fees

• Current Assignee: Sumitomo Chemical Company Limited
• Original Assignee: Sumitomo Chemical Company Limited
• Inventors: Sakaya, Taiichi, Kuroda, Toshiya, Kawakita, Toshio, Kotani, Kozo
• Primary Examiner(s): Thibodeau, Paul
• Assistant Examiner(s): TARAZANO, DONALD LAWRENCE
• Application Number:
  US08/522,423
• Time in Patent Office: 1,880 Days
• Field of Search: 106/607, 106/DIG. 4, 525/56, 428/480, 428/483, 428/481, 428/36.7, 428/357, 428/35.4, 428/454, 428/522, 428/514, 428/694 BA, 428/324, 428/323, 428/532
• US Class Current: 428/323
• CPC Class Codes: B32B 2307/7163 Biodegradable
• CPC Class Codes: B32B 2307/7244 Oxygen barrier
• CPC Class Codes: B32B 27/06 as the main or only constituent of a layer, which is next to another layer of the same or of a different material next to a layer of a particular substance B32B9/045; next to a bituminous or tarry layer B32B11/046; next to a water setting substance layer B32B13/12; next to a metal layer B32B15/08; next to a glass layer B32B17/10; next to a layer formed of natural mineral fibres or particles B32B19/045; next to a wood layer B32B21/08; next to a cellulosic plastic layer B32B23/08; next to a natural or synthetic rubber layer B32B25/08
• CPC Class Codes: B32B 27/08 of synthetic resin
• CPC Class Codes: B32B 27/18 characterised by the use of special additives
• CPC Class Codes: B32B 27/306 comprising vinyl acetate or vinyl alcohol (co)polymers
• CPC Class Codes: B32B 27/36 comprising polyesters
• CPC Class Codes: C08J 7/0423 with at least one layer of inorganic material and at least one layer of a composition containing a polymer binder
• CPC Class Codes: C08J 7/048 Forming gas barrier coatings
• CPC Class Codes: C08K 2201/008 Additives improving gas barrier properties
• CPC Class Codes: C08K 2201/016 Additives defined by their aspect ratio
• CPC Class Codes: C08K 3/346 Clay
• CPC Class Codes: Y10T 428/1341 Contains vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit
• CPC Class Codes: Y10T 428/1383 Vapor or gas barrier, polymer derived from vinyl chloride or vinylidene chloride, or polymer containing a vinyl alcohol unit is sandwiched between layers [continuous layer]
• CPC Class Codes: Y10T 428/25 Web or sheet containing structurally defined element or component and including a second component containing structurally defined particles
• CPC Class Codes: Y10T 428/251 Mica
• CPC Class Codes: Y10T 428/31786 Of polyester [e.g., alkyd, etc.]
• CPC Class Codes: Y10T 428/31797 Next to addition polymer from unsaturated monomers
• CPC Class Codes: Y10T 428/31935 Ester, halide or nitrile of addition polymer
• CPC Class Codes: Y10T 428/31971 Of carbohydrate

Abstract

The disclosed composition contains a biodegradable resin, and an inorganic laminar compound having an aspect ratio of not less than 50 and not more than 5000. A biodegradable film or shaped article includes, as at least a portion thereof, a layer (1) found from this biodegradable resin composition. The biodegradable resin composition, film or shaped article can exhibit a good gas barrier property while substantially retaining the desired biodegradability. Therefore, it can considerably contribute to the maintenance or protection of a terrestrial environment such as the disposal of trash or rubbish, or plastic wastes; and the reduction in the amount of wastes in landfills.

Claims

1. A biodegradable resin film having at least two layers having:

a first biodegradable layer comprising the composition which comprises;

a biodegradable resin which is capable of being biodegraded by the action of a microorganism, said biodegradable resin is a hydrogen-bonded resin wherein said hydrogen-bonded resin has 10% to 60% by weight of hydrogen-bonding groups selected from the group consisting of hydroxyl groups, amino groups, amide groups and thiol groups, and

an inorganic laminar compound having aspect ratio (Z) of from 100 to 3000, wherein the aspect ratio (Z) is defined by the equation (Z)=L/(a), wherein L represents the particle diameter of the inorganic laminar compound measured in a solvent by a dynamic light scattering method, and (a) represents the unit thickness of the inorganic laminar compound measured by powder x-ray diffraction, and wherein said inorganic laminar compound is swollen or cleft in a solvent; and

a second biodegradable layer comprising a material selected from the group consisting of polyester poly-3-hydroxybutyrate, 3-hydroxybutyrate-3-hydroxyvalerate copolymers, chitin, and chitosan.

2. A biodegradable resin film according to claim 1, wherein the composition has a relative ratio of the integrated intensity of the standard diffraction peak corresponding to the lattice spacing a to that of the diffraction peak corresponding to the lattice spacing d of 2 or more, wherein both the diffraction peaks are observed in the powder X-ray diffraction of the resin composition.

3. A biodegradable resin film according to claim 1, wherein the biodegradable resin a resin comprising a polyvinyl alcohol or a polysaccharide as a main component.

4. A biodegradable resin film according to claim 1, wherein the inorganic laminar compound is an inorganic laminar compound having a particle diameter of 5 μ

m of smaller.

5. A biodegradable resin film according to claim 1, wherein the inorganic laminar compound comprises a clay mineral having a swelling property.

6. A biodegradable resin film according to claim 1, wherein the biodegradable resin comprises a polyester producible by a microorganism as a main component.

7. A biodegradable resin film according to claim 1, wherein the biodegradable resin comprises a biodegradable polyester as a main component.

8. A biodegradable resin film according to claim 1, wherein the biodegradable resin film has, an oxygen permeability of not more than 0.2 cc/m² •

day•

atm under the conditions of 30°

C. and 60% RH (relative humidity).

9. A shaped article comprising a biodegradable resin film according to claim 1.

10. A biodegradable resin film according to claim 1, wherein the biodegradable resin is poly-3-hydroxybutyrate or 3-hydroxybutyrate-3-hydroxyvalerate copolymer.