JP3071881B2 - Degradable laminate composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

Ramine DOO laminate fill of the present invention relates to a thermoplastic polymer composition having easily decompose properties under the natural environment, a regenerated cellulose film (cellophane)
It relates to the arm. More specifically, a polymer and cellophane mainly containing copolymer of polylactic acid or lactic acid and oxycarboxylic acid, can be used for packaging materials, Ramine preparative laminated film decomposes under natural environmental
It relates to.

[0002]

2. Description of the Related Art In recent years, the amount of plastic used for packaging has been increasing due to the problems of aesthetics, hygiene, and packing and transportation of goods. Along with this, the amount of garbage discarded from homes and factories has increased rapidly, and the shortage of land to bury has become a serious problem around large cities.

A regenerated cellulose film called cellophane has degradability in a natural environment, and is degraded for a long time even when buried. In addition, since no harmful gas is generated even when incinerated, it is expected that the use as disposable packaging materials will increase in place of plastics having low degradability.

[0004] Cellophane is originally excellent in transparency, gas impermeability, printability and glossiness, and is in great demand as a packaging material. However, laminates with synthetic polymers are often used for the purpose of compensating for these properties because of their poor moisture-proof properties, low-temperature resistance, strength and heat-sealing properties. As a polymer used in these applications, a polyolefin-based film such as polyethylene and polypropylene has been used.

However, these polymers have almost no degradability in the natural environment, and when discarded and buried, greatly reduce the decomposition rate of cellophane, which is originally degradable. Also, when incinerated, it generates a lot of heat,
There were problems such as damage to the combustion furnace.

[0006] In recent years, lactic acid and its copolymers have become known as thermoplastic and biodegradable polymers. This lactic acid polymer is 100% biodegradable in the body of animals in months to years. In addition, when placed in soil or seawater, it decomposes in a few weeks in a humid environment and disappears in about one year. The decomposition products are all harmless with lactic acid, carbon dioxide and water.

US Patent 1,995,970,2,36
2,511,2,683,136 show a production method relating to the polymerization of lactic acid. U.S. Pat. No. 3,636,9
56, 3,797,499 show a method for producing a copolymer of lactic acid and glycolic acid. The polymer of lactic acid is
It is synthesized from a cyclic dimer of lactic acid, usually called lactide. When glycolic acid is copolymerized, ring opening polymerization is performed by mixing lactide and glycolide, which is a dimer of glycolic acid. When a polymer is directly synthesized from lactic acid or a mixture of lactic acid and glycolic acid by dehydration condensation, a polymer having a high molecular weight cannot be obtained even for a long time. On the other hand, a linear polyester synthesized by ring-opening polymerization using lactide or lactide and glycolide as raw materials has a high molecular weight.

[0008]

The present invention invention is to solve the above is, without the above-mentioned drawbacks, an object of the present invention is to provide a Ramine door laminated film which does not cause a problem when it is incinerated or disposed of in the natural environment.

[0009]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above problems, and as a result, polylactic acid having a property of decomposing for a long time in soil or water has been used as a main component. When the film is bonded to the cellophane to show adequate adhesion, also the Ramine DOO laminated film, transparency,
The inventors have found that they have excellent glossiness and moisture-proof properties and have even greater strength, and have completed the present invention.

The polymer used in the present invention is a mixture of polylactic acid and a polymer of another hydroxycarboxylic acid, or a copolymer of lactic acid and another hydroxycarboxylic acid. As other hydroxycarboxylic acids, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 5-hydroxyvaleric acid, 6-hydroxycaproic acid and the like are used.

These polymers may be those synthesized by direct dehydration polycondensation from lactic acid or other hydroxycarboxylic acids, or ring-opening polymerization of lactide, glycolide, ε-caprolactone, or a mixture thereof. A product obtained by doing so may be used. Alternatively, a copolymer synthesized by subjecting a polymer of polylactic acid and another hydroxycarboxylic acid to a transesterification reaction at a high temperature may be used. The lactic acid constituting the polymer may be L-lactic acid, D-lactic acid or a mixture thereof.

The average molecular weight of the polymer is between 10,000 and 100
10,000 is preferred. If the molecular weight is lower than this, the strength of a molded article such as a film is small and is not suitable for practical use. Also,
If the molecular weight is higher than this, the viscosity in a molten state when heated is high, and the moldability is poor.

[0013] Cellophane kind used in Ramine preparative laminated film of the present invention is not particularly limited, normally cellophane,
Moisture-proof cellophane is used.

Known laminating methods include a solution coating method, a hot melting method, and an extrusion laminating method. When an adhesive is used, it is preferable to use a degradable substance such as glue, gelatin, casein, and starch. Further, a method of anchor-coating the surface of cellophane paper with an organic titanium compound or polyethylene imine before lamination is also used.

The degradable Ramine preparative laminated film of the present invention may also be laminated with <br/> yet another film, for example, aluminum thin or paper.

[0016]

EXAMPLES The method of the present invention will be specifically described below with reference to examples.

EXAMPLE 1 30% gelatin was applied as an adhesive to a cellophane paper of 150 mm × 150 mm and 50 μm in thickness, and a weight average molecular weight of 1
A 30 μm thick film obtained from 50,000 poly L-lactic acid was overlaid and pressed overnight at a pressure of 1 kg / cm ² , and then dried at 60 ° C. for 1 day. The adhesive strength between cellophane and polymer film was good, and a strong film was obtained. This laminate film was subjected to a decomposition test in a compost at 40 ° C.
A month later, when taken out and examined, the film had deteriorated and easily collapsed due to external force.

Example 2 The same polylactic acid film as used in Example 1 was overlaid on cellophane paper of 150 mm × 150 mm and 50 μm in thickness, and pressed with a hot press at 200 ° C. under a pressure of 30 kg / cm ² for 5 minutes.
The adhesive strength between cellophane and polymer film was good, and a durable and beautiful film with good surface gloss was obtained. This laminate film was subjected to a decomposition test in a compost at 40 ° C.
A month later, when taken out and examined, the film on the surface was deteriorated and easily collapsed by external force.

Example 3 Instead of a film of poly-L-lactic acid, a weight average molecular weight of 1
Example 2 except that a 25 μm thick film obtained from a 10,000: 1 9: 1 copolymer of L-lactic acid and D-lactic acid was used.
A laminate film was obtained in the same manner as described above. The adhesive strength between cellophane and polymer film was good, and a durable and beautiful film with good surface gloss was obtained. Further, the laminated film was subjected to a decomposition test in a compost at 40 ° C. and taken out and examined after two months. The film was deteriorated and easily deformed by an external force.

Example 4 Instead of a film of poly L-lactic acid, a weight average molecular weight of 5
A laminated film was obtained in the same manner as in Example 2, except that a 25 μm thick film obtained from a 1: 1 copolymer of L-lactic acid and glycolic acid was used. The adhesive strength between cellophane and polymer film was good, and a durable and beautiful film with good surface gloss was obtained. Further, the laminated film was subjected to a decomposition test in a compost at 40 ° C. and taken out and examined after two months. The film was deteriorated and easily deformed by an external force.

Example 5 Instead of a film of poly-L-lactic acid, a weight average molecular weight of 6
A laminate film was obtained in the same manner as in Example 2, except that a 25 μm thick film obtained from a 1: 1 copolymer of L-lactic acid and 6-hydroxycaproic acid was used. The adhesive strength between cellophane and polymer film was good, and a durable and beautiful film with good surface gloss was obtained. Further, the laminated film was subjected to a decomposition test in a compost at 40 ° C. and taken out and examined after two months. The film was deteriorated and easily deformed by an external force.

Example 6 0.5 g of a 5% chloroform solution of poly-L-lactic acid having a molecular weight of 110,000 was applied to cellophane paper having a thickness of 150 μm and a thickness of 50 μm, and dried overnight at room temperature. The obtained laminate film was dried under reduced pressure at 50 ° C. When the laminated film was subjected to a decomposition test in a compost at 40 ° C. and taken out and examined one month later, the film was deteriorated and easily deformed by external force.

[0023]

Industrial Applicability According to the present invention, a laminating material which decomposes in a natural environment such as soil or water for a certain period of time, has excellent transparency and moisture resistance, and has a strong surface with a high gloss and a beautiful appearance. door laminated film can Rukoto obtain a.

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Norimasa Shinoda 2-1-1 Tango-dori, Minami-ku, Nagoya-shi, Aichi Mitsui Toatsu Chemicals Co., Ltd. (56) References JP-A-4-334448 (JP, A) JP-A-2-222421 (JP, A) Jikken 37-29460 (JP, Y1) (58) Fields investigated (Int. Cl. ⁷ , DB name) B32B 1/00-35/00 B65D 65/40

Claims (3)

(57) [Claims] 1. A thermoplastic biodegradable polymer-safe mainly containing copolymer of polylactic acid or lactic acid and oxycarboxylic acid
And Irumu, degradable laminating <br/> Natick preparative laminated film comprising a regenerated cellulose film. Wherein lactic acid is D- lactic, L- lactic acid or Ramine bets laminated fill of claim 1 wherein a mixture thereof
M Wherein hydroxycarboxylic acid is glycolic acid or 6-hydroxycaproic acid and laminating <br/> Natick preparative laminated film according to claim 1, wherein,.