JPH10109382A - Laminated or coated regenerated cellulose film and its manufacture - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a solid residue from being generated when a regenerated cellulose film is discarded as refuse and buried in the soil by laminating or coating a biodegradable resin on a regenerated cellulose film through an anchoring agent consisting of a hydrophilic polymer compound. SOLUTION: First, an anchoring agent consisting of a synthetic polymer compound such as a polyvinyl alcohol resin dissolved in a hydrophilic solvent such as methanol is applied to the surface of cellophane and the coat is dried. Further, a resin liquid or an aqueous dispersion consisting of a biodegradable resin with biodegradability such as a polymer of hydrocarboxylic acid dissolved is applied and dried to obtained a coated film. The coated film thus obtained has biodegradability in not only a regenerated cellulose film but also in the biodegradable resin applied. In addition, the anchoring agent is also degradable in the soil and is soluble in water so that no residue is generated. Thus it is possible to bury this regenerated cellulose film in the soil as a method for disposing of refuse.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a regenerated cellulose film obtained by laminating or coating a biodegradable resin via a predetermined anchoring agent.

[0002]

2. Description of the Related Art A regenerated cellulose film obtained from viscose, that is, cellophane, is a so-called biodegradable resin that is decomposed by microorganisms. This cellophane is highly transparent, glossy, has high gas barrier properties and oil resistance, has excellent printability, and has moderate waist strength and slipperiness, and has no chargeability. However, they have the disadvantages of low strength such as tensile strength and tear strength, low water resistance, and lacking in thermal adhesiveness, that is, lack of heat sealability.

[0003] Therefore, it is known to improve the strength, water resistance, and heat sealing property by laminating a cellophane with a polyethylene film or the like, and this laminated film is widely used in the field of light packaging mainly for food products. Has uses.

[0004]

However, when the above-mentioned laminated film of cellophane and polyethylene film is used and buried in the soil when discarded as garbage,
Although the cellophane portion is decomposed in the soil, the polyethylene film portion remains without being decomposed in the soil. As a result, environmental pollution is caused, which is not preferable. Further, when the laminated film is incinerated, polyethylene is burned while generating a large amount of heat, so that there is a problem that the incinerator is damaged.

[0005] Further, it is conceivable to recycle the laminated film, but it is difficult to separate the laminated film for each layer. Therefore, it is difficult to collect the laminated film for each type of resin constituting each layer. Even in the case of recycling without peeling off each layer, since printing is performed on the cellophane layer side between both layers, it is difficult to remove ink and it is difficult to recycle.

[0006] Therefore, an object of the present invention is to provide a regenerated cellulose film laminate that does not generate a solid residue when discarded as garbage and buried in soil.

[0007]

In order to solve the above-mentioned problems, the present invention is obtained by laminating or coating a biodegradable resin on a regenerated cellulose film via an anchor agent comprising a hydrophilic polymer compound.

Since the biodegradable resin is laminated or coated on the regenerated cellulose film, not only the regenerated cellulose film layer but also the laminated or coated biodegradable resin layer is decomposed,
As a garbage disposal method, it is possible to bury the soil.

In addition, when a biodegradable resin is laminated or coated on a regenerated cellulose film, a hydrophilic polymer compound is used as an anchoring agent. In the middle, decomposition by microorganisms, hydrolysis, etc., or dissolves in water in the soil, so that it is possible to prevent the anchor agent from remaining in the soil, the above-mentioned laminated film or coating film is used as a garbage disposal method in the soil Can be buried.

Further, since the biodegradable resin is laminated or coated on the regenerated cellulose film, the properties such as strength of the biodegradable resin itself are imparted to the regenerated cellulose film, thereby avoiding the drawbacks of the regenerated cellulose film itself. be able to.

Further, since a hydrophilic polymer compound is used as the anchoring agent, not only the adhesiveness between the biodegradable resin film and the anchoring agent but also the adhesiveness between the regenerated cellulose film and the anchoring agent are improved. Adhesion between the resin film and the regenerated cellulose film can be improved.

Further, the laminating conditions for laminating the biodegradable resin on the regenerated cellulose film do not require any special pressing conditions, and the pressing by a pressing roller used in an ordinary extruder or the like is sufficient. The regenerated cellulose film layer and the biodegradable resin layer can be joined. That is, the above-mentioned laminated body can be manufactured by an ordinary extrusion molding machine or the like without preparing a special device such as a press machine.

[0013]

Embodiments of the present invention will be described below. The laminated or coated regenerated cellulose film according to the present invention is obtained by laminating or applying a biodegradable resin to a regenerated cellulose film via an anchor agent composed of a hydrophilic polymer compound.

The above-mentioned regenerated cellulose film is a film obtained from viscose and is referred to as cellophane (hereinafter, the regenerated cellulose film is referred to as cellophane). The type of cellophane used is not particularly limited, and for example, ordinary cellophane or moisture-proof cellophane can be used.

The above-mentioned biodegradable resin refers to a resin decomposed by microorganisms, and any resin may be used as long as it has microbial degradability. Examples of such resins include homopolymers and copolymers of hydroxycarboxylic acids, ester polymers of diols and dicarboxylic acids, ring-opening polymers of caprolactones, and polysaccharides.

The monomers and dimers used in the homopolymers and copolymers of the hydroxycarboxylic acids include glycolic acid, lactic acid, glycolide, lactide, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, -Hydroxyvaleric acid, 6-hydroxycaproic acid and the like. The diols used in the ester polymer include ethylene glycol,
Examples thereof include 1,3-propanediol and 1,4-butanediol, and examples of the dicarboxylic acid include succinic acid and fumaric acid.

Further, examples of the monomers used for the ring-opening polymer of caprolactones include ε-caprolactone and the like, and examples of polysaccharides include starch and cellulose. The polysaccharide itself may be insufficient in terms of strength and the like, and in this case, a modified polysaccharide that has been modified can be used. Examples of modified starch include PVA-modified starch modified with polyvinyl alcohol (PVA).
In addition, examples of the modified cellulose include cellulose acetate modified with acetic acid.

Examples of commercially available biodegradable resins include polylactic acid ("Lacty" manufactured by Shimadzu Corporation and "LACEA" manufactured by Mitsui Toatsu Chemicals, Inc.), 3-hydroxybutyric acid / 4
-Hydroxyvaleric acid copolymer ("Biopol" manufactured by UK-based Zeneca), polybutylene succinate ("Bionole" manufactured by Showa Polymer Co., Ltd.), PVA-modified starch ("Matterby" manufactured by Nippon Synthetic Chemical Company), polycaprolactone ( Examples include “Tone” manufactured by Nippon Unicar, “Placcel” manufactured by Daicel Chemical), and cellulose acetate (“Lunare” manufactured by Nippon Shokubai).

The anchor agent comprising the above-mentioned hydrophilic polymer compound is indispensable when cellophane and biodegradable resin are compounded, and has an anchoring effect on both cellophane and biodegradable resin. . This anchor agent, when buried in the soil, since both the cellophane and the biodegradable resin are degraded by microorganisms, a biodegradable compound that does not retain solids in the soil, a hydrolyzable compound, or Water-soluble compounds are preferred. Further, since it is used by dissolving it in a solvent in order to facilitate coating on cellophane, it is preferable that it be soluble in a solvent.

Examples of such a compound include a natural polymer compound having a polar functional group and a synthetic polymer compound. Examples of the natural polymer include proteins such as collagen, gelatin and glue, polysaccharides such as chitosan, and modified compounds thereof. These are all hydrophilic and have good adhesiveness not only to the biodegradable resin but also to cellophane.

Examples of the synthetic high molecular compound include a polyester resin having an ester bond, a polyvinyl alcohol resin such as polyvinyl alcohol (PVA) having a hydroxy group, and an adhesive composed of a modified resin thereof. . Each of these compounds contains a hydrophilic group and has good adhesiveness not only to a biodegradable resin but also to cellophane. Among these, polyvinyl alcohol (PVA) resin is particularly preferred from the viewpoint of immediate effect of disappearing in soil.

Examples of the solvent for dissolving the above compound include hydrophilic solvents such as methanol, ethanol, propanol, acetone and methyl ethyl ketone. If necessary, a hydrophobic solvent such as toluene is mutually dissolved in these solvents. A solvent dissolved in the range to be obtained can be used. Since these solvents are easy to volatilize, they are easy to dry after being applied to cellophane. In addition, since the anchoring agent needs to have an anchoring effect on both cellophane and the biodegradable resin, a certain number of hydrophilic groups are required in the molecule.

The anchor agent is decomposed by microorganisms in the soil, hydrolyzed by moisture in the soil, or
Since it is a soil-extinguishing compound that dissolves in soil moisture, no solid remains when buried in the soil.

A laminated film or a coated film obtained by laminating or coating the above biodegradable resin on the above cellophane via the above anchoring agent is formed from a microbial degradable and soil extinguishable resin. When buried, the prototype is not retained and no residue is produced.

The above biodegradable resin has higher strength such as tensile strength and tear strength than cellophane, and has water resistance and heat sealability. Therefore, a laminated film obtained by laminating or applying these is used. And the coated film becomes a film having higher strength and improved water resistance and heat sealability as compared with cellophane itself.

When a transparent resin such as cellulose acetate or polylactic acid is used as the biodegradable resin, the resulting laminated film or coated film maintains transparency. Further, when a resin having translucency other than polylactic acid is used as the biodegradable resin, the thickness of the coating is about several μm, and the thickness of the laminate is about several tens to one hundred and several tens μm. Therefore, it does not become translucent due to the thickness of the coating or the lamination, and sufficiently maintains transparency.

Next, a method for producing the above-mentioned laminated or coated cellophane will be described. First, an anchor agent dissolved in the above solvent is applied to the surface of cellophane. Next, the solvent is dried. Thereby, the anchor agent can be exposed on the cellophane surface, and when the biodegradable resin is applied or laminated, it is easily bonded and hardly causes peeling.

Then, a coated film can be produced by applying and drying a resin solution or an aqueous dispersion in which the biodegradable resin is dissolved. As the solvent for dissolving the biodegradable resin at this time, any solvent can be used in accordance with the biodegradable resin. However, it is preferable to have volatility because it is dried. further,
In the case of dispersing in water, if only water is used as the solvent, cellophane is affected, and therefore, a mixed solution of water and a hydrophilic solvent is preferably used as the solvent.

In the case of producing a laminated film, the above-mentioned biodegradable resin is hot-melted to cellophane coated with the above-mentioned anchoring agent and dried to form a film, and laminated by passing between pressure rolls. be able to. At this time, since the laminated biodegradable resin film is easily joined by the anchor agent, it is not particularly necessary to perform a pressure treatment, and the film is passed between pressure rolls of a normal extruder, that is, 170-200 ° C, 1-5kg /
A pressure of 0.1 to 1 second in cm ² is sufficient.

According to the above-mentioned method, 5 to 1 on cellophane.
A biodegradable resin coating having a thickness of 0 μm can be formed, and a biodegradable resin film having a thickness of 20 to 150 μm can be laminated on cellophane.

The thus-obtained laminated film or coated film has suitable strength, water resistance, and other characteristics, and can be used for food packaging, pharmaceutical packaging, and agriculture.

[0032]

Next, examples of the present invention will be described below.

Preparation of Anchor Agent Solution An anchor agent solution was prepared using the anchor agent and the diluting solution shown in Table 1 according to the adjusting method shown in Table 1. Since then
The notation of each anchor agent solution is represented by the abbreviation described in the leftmost column of Table 1. Note that MEK in Table 1 indicates methyl ethyl ketone, and the manufacturers of the anchor agents described in Table 1 are as shown below.・ Pesthresin S-1130: Modified polyester adhesive manufactured by Takamatsu Yushi Co., Ltd. ・ Pesresin S-253D: Modified polyester adhesive manufactured by Takamatsu Yushi Co., Ltd. ・ Pesthresin S-313D: Modified polyester adhesive manufactured by Takamatsu Yushi Corporation ・ TKR-635 6: Modified polyester adhesive manufactured by Takamatsu Yushi Co., Ltd. ・ MC-1243Z: Collagen aqueous solution manufactured by Takamatsu Yushi Co., Ltd. ・ SMR-150L: Modified PVA adhesive manufactured by Shin-Etsu Chemical Co., Ltd. ・ Chitosan CLH: Chitosan-lactic acid aqueous solution manufactured by Yaizu Suisan Chemical Co., Ltd. ・Gelatin: Aqueous gelatin solution manufactured by Nacalai Tesque, Inc.-Eslek BL-1: Butyral resin adhesive manufactured by Sekisui Chemical Co., Ltd.-Eslec BL-S: Butyral resin adhesive manufactured by Sekisui Chemical Co., Ltd.-Eslec BM-1: Butyral resin manufactured by Sekisui Chemical Lactic acid was added in the chitosan solution. This is to a water-soluble chitosan as a salt.

[0034]

[Table 1]

Examples 1 to 8 Production of Coated Film An anchor solution shown in Table 1 was coated on the surface of cellophane (No. 300 manufactured by Rengo Co., Ltd.) using a Meyer bar, and the thickness was 2
A μm layer was formed. Then, the hot air dryer 100
C. for 2 minutes to evaporate the diluting solvent to produce cellophane coated with an anchor agent. Next, cellulose acetate containing triacetin (manufactured by Nippon Shokubai Co., Ltd .: Runare) was dissolved in ethyl acetate to prepare a viscous, translucent 10% solution, which was applied to the above surface, and then heated in a hot air drier. 11
It was dried at 0 ° C. for 3 minutes to produce a biodegradable resin-coated cellophane. The thickness of the obtained cellulose acetate coating is 5 μm
Met. The obtained cellophane coated with the anchor agent and the cellophane coated with the biodegradable resin were subjected to a releasability test by the following method, and the releasability of the anchor agent and the releasability of the Lunale coat layer as the biodegradable resin layer were examined. In addition, the change when buried in the soil was examined by the following method. Table 2 shows the results. Further, the coating of Example 6 was applied at 180 ° C., 1
Heat was applied for 2 seconds at kg / cm ² to perform heat sealing. When the seal strength of this seal was measured by the following method, it was 150 g / 15 mm.

Peelability test A commercially available cellophane tape was affixed to the coated surface, and the tape was peeled off at once at an angle of about 90 ° C., and the presence or absence of peeling of the coat layer at this time was examined .

The soil burying test sample is buried in the soil having a depth of 25 cm and left for 3 months. Thereafter, the sample was taken out and its appearance was observed.

Seal Strength Test The surfaces of the seals were joined together and heated at a constant temperature and a constant pressure for several seconds to be fused at a width of 15 mm and a length of 5 mm, and the strength of the seal was measured by a Shopper type strength measuring instrument.

[Comparative Examples 1 to 3] Coated films were produced in the same manner as in Example 1 except that an anchor agent solution containing a hydrophobic compound shown in Table 2 was used. The peeling test and the burial test in the soil of the obtained coated film were performed according to the above-mentioned methods. Table 2 shows the results.

[0040]

[Table 2]

Results As is evident from Examples 1 to 8, the biodegradable resin Lunare in ethyl acetate was translucent,
, Almost became transparent. However, when the protein-based compound was used as an anchoring agent, it became slightly cloudy after drying. Further, from the peelability test, it was revealed that the peel strength was high when the anchor agents of Examples 1 to 8 were used. In contrast, Comparative Examples 1 to 3
It was found that when the anchor agent was used, the peel strength was weak, and it could not be used. Furthermore, from the soil burial test,
It was found that when left in the soil for one month, it was decomposed to such an extent that the prototype was not retained.

Example 9 Production of Laminated Film Modified PV shown in Table 1 was applied to the surface of cellophane used in Example 1.
An anchor solution consisting of Solution A was coated with a Meyer bar to form a layer having a thickness of 3 μm. Next, it was dried at 100 ° C. for 2 minutes in a warm air drier to evaporate the diluting solvent.
Subsequently, a polybutylene succinate resin film (Bionole 3000, manufactured by Showa Kogyo Co., Ltd.) was laminated on the above-mentioned anchored cellophane, and the melt-extrusion molding apparatus was used to form a film.
The film was applied to a pressure roller under the conditions of 0 ° C. and 3 kg / cm ² , and a 30 μm polybutylene succinate resin film was laminated on cellophane. The time during which the pressure was applied by the pressure roller was less than 1 second. The peelability of the obtained laminated film was examined by the above method. The result was good without any peeling. Further, the obtained laminated film was subjected to a soil burying test by the above method. As a result, the cellophane part completely disappeared after being left in the soil for three months, and was not retained at all as a prototype. In addition, the biodegradable resin was also finely broken into small pieces, indicating that the decomposition was progressing. Further, when a seal strength test was performed according to the above method, the seal strength was 200 g.
/ 15 mm.

[0043]

According to the present invention, not only the regenerated cellulose film but also the laminated or coated biodegradable resin has degradability in the obtained laminated film or coated film. Since it is decomposed or dissolved in water, no residue is generated, and burying treatment in soil as a waste disposal method becomes possible.

In addition, since the biodegradable resin is laminated or coated, the properties such as the strength of the biodegradable resin are imparted to the regenerated cellulose film, and the disadvantages of the regenerated cellulose film itself such as low strength are compensated. Can be.

Furthermore, since the biodegradable resin is laminated or coated on the regenerated cellulose film, the properties such as strength and heat sealing property of the biodegradable resin itself are imparted to the regenerated cellulose film, and the regenerated cellulose film itself has Disadvantages can be avoided.

Further, since a hydrophilic polymer compound is used as the anchoring agent, not only the adhesiveness between the biodegradable resin film and the anchoring agent but also the adhesiveness between the regenerated cellulose film and the anchoring agent are improved. Adhesion between the resin film and the regenerated cellulose film can be improved.

Furthermore, the laminating conditions for laminating the biodegradable resin on the regenerated cellulose film do not require any special pressing conditions, and the pressing by a pressing roller used in an ordinary extruder or the like is sufficient. The regenerated cellulose film layer and the biodegradable resin layer can be joined.

Claims (3)

[Claims] 1. A laminated or coated regenerated cellulose film obtained by laminating or coating a biodegradable resin on a regenerated cellulose film via an anchor agent made of a hydrophilic polymer compound. 2. The laminated or coated regenerated cellulose film according to claim 1, wherein the hydrophilic polymer compound is a resin selected from a polyester resin, a polyvinyl alcohol resin or a modified resin thereof. 3. Applying a hydrophilic polymer compound dissolved in a solvent to the surface of a regenerated cellulose film, drying the film, and then laminating a film made of a biodegradable resin and laminating the film by passing between pressure rolls, or , Apply biodegradable resin,
A method for producing a laminated or coated regenerated cellulose film to be dried.