JPH04136067A - Packaging material - Google Patents

Abstract

PURPOSE:To provide a packaging material excellent in bio-degradability, flexibility, processability, strength, heat resistance, etc., by mixing a polyhydroxyalkanoate polymer with a specified amount of a lipid compound and a resin and molding the resulting mixture. CONSTITUTION:A base comprising a polyhydroxyalkanoate or its copolymer (e.g. 3-hydroxybutyrate/3-hydroxypropionate copolymer) or a mixture thereof is mixed with 0.01-60wt.% lipid compound (e.g. glycerol triacetate). The obtained biodegradable composition is mixed with 1-70wt.% resin (e.g. polyethylene terephthalate). The obtained resin composition is molded into a packaging material in the form of a sheet, a bag, a cup or the like. This packaging material can be biodegraded within a short time even when it is left standing in an atmosphere after being used, so that it does not cause environmental pollution.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a packaging material that is not only biodegradable but also has excellent performance in terms of flexibility, workability, strength, etc.

<Conventional technology> Medical products, foodstuffs, various industrial products, etc. are packaged in various packaging materials such as sheets, bags, and boxes to prevent stains and damage, and to improve aesthetics and product value. It is distributed on the market in the same condition.

Traditionally, paper was the most commonly used packaging material, but in recent years various resin materials, such as soft polychlorinated Vinyl, low-density or high-density polyethylene, linear low-density polyethylene, polypropylene, polystyrene, ionomers, various resins such as polyvinylidene chloride, polyvinyl acetate, polyvinyl alcohol, polyacrylonitrile, polymethyl methacrylate, nylon, polyester, etc. Copolymers and mixtures are applied as materials.

Packaging materials to which such resins are applied are made by mixing various additives such as plasticizers, softeners, cross-linking agents, antioxidants, and lubricants with the resin as necessary, and are made into films, sheets, and plates. , molded into a box shape, bottle shape, etc., or composited multiple types of molded films using coextrusion or lamination technology,
Furthermore, if necessary, by irradiating ionizing radiation after molding to promote crosslinking, various physical properties depending on the packaged item,
It is used as a shaped packaging material.

By the way, most packaging materials using resin as materials are disposable, and after being used for their respective purposes, they are disposed of as waste without being collected. However, the aforementioned resins do not naturally decompose (even if they are discarded, they remain in their original form without disintegrating for many years, causing various social problems such as environmental pollution). It is a well-known fact that
There is a method to dispose of it by incineration, but resin materials such as those mentioned above cannot be incinerated unless they are at high temperatures, and if toxic gases, mainly halides, are generated, there is no equipment to remove them. Therefore, expensive equipment is required and running costs are also high. Furthermore, the release of carbon dioxide gas generated by incineration is not just environmental pollution, but is also evolving into a major problem of global warming.

In response to these various problems, in recent years traditional paper packaging has been reconsidered, and so-called biodegradable materials, which are polymeric materials that can be decomposed by the natural ecosystem when discarded or left in the natural world, have been widely used. It is being studied and attracting attention.

<Problems to be Solved by the Invention> However, packaging materials made of paper have limited physical properties, and are therefore severely limited in terms of strength, freedom of shape, etc., and it is difficult to obtain the necessary characteristics depending on the packaged item. In addition, since paper uses wood valves as the main raw material, large consumption is not very desirable from the perspective of preserving forest resources.

Furthermore, poly(3-hydroxybutyrate) or a copolymer containing poly(3-hydroxybutyrate) as a main component is known as a biodegradable material. It has been confirmed that poly(3-hydroxybutyrate) decomposes well when left in the natural environment, and it also has excellent biocompatibility, so it was expected to be used in a variety of fields. . however,
Poly(3-hydroxybutyrate) is hard and brittle, so there are problems with its physical properties such as poor impact resistance, and although it has thermoplasticity, it begins to decompose even below its melting point, making it difficult to process. Therefore, it is difficult to apply it to packaging materials that require various shapes and physical properties depending on the packaged items.

On the other hand, as an attempt to change the physical properties of poly(3-hydroxybutyrate), D-(-)3-hydroxybutyrate and D-
Copolymers having repeating units such as (-)3-hydroxyvalerate are known. Although this copolymer has good effects in terms of lower melting point and flexibility, it requires a special substrate and has low productivity, making it expensive, and it is not suitable for general-purpose use such as packaging materials. There are problems in terms of usage.

Furthermore, attempts have also been made to modify poly(3-hydroxybutyrate) by mixing it with other resin materials such as ethylene oxide, ethylene propylene rubber, polyvinyl acetate, etc. However, either method leaves problems with the stability, economy, processability, etc. of the resulting resin composition, making it difficult to apply it to packaging materials.

Furthermore, packaging materials are required to have good biodegradability, flexibility, processability, etc., as well as performances required for packaging materials, such as tensile strength, breaking strength, heat resistance, and gas barrier properties.

The purpose of the present invention is to solve the problems of the prior art, and by using a specified resin composition as a material, it has excellent biodegradability and can be disposed of in a landfill or in the ocean after use. By leaving it in the natural environment, it decomposes in a short time and does not cause environmental pollution.It also has excellent processability and economic efficiency, and also has the bowing strength, breaking strength, and heat resistance required for packaging materials. properties, gas barrier properties, chemical resistance, water resistance,
The object of the present invention is to provide a packaging material that can also satisfy performance such as printability.

Means for Solving the Problems> In order to achieve the above object, the present invention provides a polyhydroxyalkanoate, a copolymer thereof, or a mixture thereof as a main component, and a lipid compound in an amount of 0.01 to 6
A packaging material characterized by being molded from a biodegradable composition containing 0% by weight and 1 to 70% by weight of a resin.

Further, the polyhydroxyalkanoate may be poly(3-
Hydroxyalkanoates) are preferred.

Further, the polyhydroxyalkanoate is poly(4-
Hydroxyalkanoates) are preferred.

Further, the polyhydroxyalkanoate may be poly(5-
Hydroxyalkanoates) are preferred.

In addition, it may be film-like, sheet-like, cylindrical, box-like, bag-like, hollow cylinder-like, cup-like, concave-shaped, bottle-like, string-like, band-like, spherical, net-like, or two of these shapes.
It is preferable that the shape is a combination of the above.

Further, the resins include polyvinyl chloride, low density or high density polyethylene, linear low density polyethylene, polypropylene, polystyrene, ionomer, polyvinyl acetate, polyvinyl alcohol, polyacrylic acid, polyacrylic acid ester, polymethacrylic acid, polyvinyl acetate, polyvinyl alcohol, polyacrylic acid, polyacrylic ester, polymethacrylic acid, Preferably, it is one or more selected from the group consisting of methacrylic acid ester, nylon, polyester, polyethylene terephthalate, polyvinylidene chloride, polyvinylidene fluoride, polyurethane, and copolymers containing these.

Hereinafter, a specific configuration of the present invention will be explained in detail.

The packaging material of the present invention comprises a biodegradable composition containing polyhydroxyalkanoate, a copolymer thereof, or a mixture thereof as a main component and containing 0.01 to 60% by weight of a lipid compound; It is molded from 70% by weight of resin.

In other words, the packaging material of the present invention has a lipid compound/(polyhydroxyalkanoate+lipid compound)=0.01 to 60w.
Contains a biodegradable composition having a composition of t% and various resins, resin/(biodegradable composition + resin) = 1 to 70w
It is made of a material having a composition of t%.

The packaging material of the present invention may be formed from a composite material in which a biodegradable composition and a resin are mixed, or may be formed from a laminate material of a biodegradable composition and a resin. formed from either a degradable material or a resin chair;
This includes all forms, including those at least partially formed by the other.

The packaging material of the present invention has good productivity, processability,
It is economical, has excellent biodegradability, and also has the tensile strength, elongation at break, tear strength, and
Heat resistance, gas barrier properties, solvent resistance, chemical resistance, water resistance,
Various performances such as printability and high-speed sealing properties can be improved as needed, so it can be suitably applied to various uses, is inexpensive, and can be left in natural environments such as underwater or soil. As a result, it decomposes well and does not cause environmental pollution due to disposal.

Here, in the present invention, packaging materials include not only films and sheets, but also those processed into cylinders, bags, boxes, bottles, etc., composites of various shapes, and even a plurality of bottles.
It includes all materials used to wrap or fill at least a portion of a certain item, regardless of whether it is a liquid, gas, or any other structure, such as string-like or band-like members used to bind cans, etc.

The packaging material of the present invention uses a biodegradable material that has polyhydroxyalkanoate, a copolymer thereof, or a mixture thereof as a main component and contains 0.01 to 60% by weight of a lipid compound, and has good biodegradability. A degradable composition is included as a material.

Examples of applicable polyhydroxyalkanoates include those having about 3 to 12 carbon atoms as a hydroxyalkanoate repeating unit, and specifically, poly(3
poly(3-hydroxyalkanoates), such as poly(3-hydroxypropionate), poly(3-hydroxybutyrate), poly(3-hydroxyvalerate), poly(3-hydroxyoctanoate); Poly(4-hydroxyalkanoates) such as hydroxybutyrate), poly(4-hydroxyvalerate), and poly(5-hydroxyalkanoates such as poly(5-hydroxyvalerate)) are preferably used. Among them, poly (
3-hydroxybutyrate) is preferably applied.

In the present invention, not only a single polyhydroxyalkanoate but also a copolymer thereof can be suitably applied. As a copolymer of polyhydroxyalkanoate, poly(
Copolymers of 3-hydroxybutyrate) and other hydroxyalkanoates having 3 to 12 carbon atoms are exemplified,
Specifically, (3-hydroxybutyrate) (3-hydroxypropionate) copolymer, (3-hydroxybutyrate)-(3-hydroxypropionate)-(
4-hydroxybutyrate) copolymer, (3-hydroxybutyrate)-(3-hydroxyvalerate) copolymer, (3-hydroxybutyrate)(3-hydroxyvalerate)-(3-hydroxyalkanoate)-
(3-hydroxyheptanoate) copolymer, (3-
hydroxybutyrate)-(3-hydroxyvalyrate)(3-hydroxyhexanoate)-(3-hydroxyheptanoate)-(3-hydroxyoctanoate) copolymer, (3-hydroxybutyrate)-(3 −
Hydroxyhexanoate)-(3-hydroxyoctanoate) copolymer (3-hydroxybutyrate)
(3-hydroxyvalerate)-(3-hydroxyheptanoate)-(3-hydroxyoctanoate) copolymer (3-hydroxybutyrate)-(3-hydroxyvalerate) (3-hydroxyvalerate) −(3
-hydroxyheptanoate)-(3-hydroxyoctanoate)-(3-hydroxynonanoate)-)-(
Preferred examples include (3-hydroxyvalerate)-(3-hydroxyundecanoate)-(3-hydroxylaurate) copolymer, (3-hydroxybutyrate)-(4-hydroxyvalerate) copolymer, etc. However, it is not particularly limited to these.

In addition, in the present invention, a mixture of the above-mentioned polyhydroxyalkanoates or a mixture of the above-mentioned copolymers,
Furthermore, a mixture of the two can also be suitably applied.

These polyhydroxyalkanoates and their copolymers are produced by various microorganisms, as is well known, but in the present invention, they may be produced by any of them. It may be obtained by synthesis.

Examples of microorganisms that produce polyhydroxyalkanoates include Acinetobacter [Ac1netobacter].
erl, Actinomycetus [Acti
nomycetesl, alcaligenes [Alcal
igenes] Aphanothe [Aphanothe]
ce], Aquaspirillum [Aquaspirillum]
uml Azospirillum
], Azotobacter, Bacillus, Beggi
Btoa], Be1jerinck
ial, Caulobacter
, Chlorofrexeus J,
Chloroproair [(:hlorogl.

ea], Chromatium, Chromobacterium
, Clostridium ,
Derxia, Ectothiorhodospira, Escherichia, Ferobacillus [F
errobacillus, Gamphosphaeria, Haemophilus [
Haemophilus J Halobacterium [Halo
bacterium, Aifomicrobium [H
yphomicrobium], lamprocytis [
Lamprocystis], Lamprobedia [La
mpropedial, Lebutothrix [Lept.
othrixl.

Methylobacterium [Methylobacterium]
ml, MeLhylocysti
sl, Micrococcus
, Micrococcus [Microc.

1eusl, Microcystis
tis] Moraxellal, Mycoplanal, Nitrobacter [N
1trobacter], Nitrococcus [N1tr
ococcus], Nocardia
, Oceanospirillum [Oceanospirillum]
ml, Paracoccus, Photobacterium, Pseudomonas, Rhizobium, Rhodobacterium
dobacterl, Rhodosvirilum [Rhodos
pirilum], Sphaerochilus [5phaero
tilus], Spirillum,
Spirulina [5pirulinal], Streptomyces [Streptomyces], Syntrophomonas [Syntrophomonasl, Thiobarasis]
Th1obacillus], Thiocabillus [Th1oc
apsa] Th1ocysti
sl, Th1odiction
, Thiopedia, Th1osphaera, Vibrio
brio], Santobacter [Xanthobacterium]
Various bacteria belonging to the bacterial species such as Rl, Zoogloeal and the like are exemplified.

The number average molecular weight Mw of the polyhydroxyalkanoate and its copolymer synthesized by fermentation in this way is usually 1.
It is about 0.000-3.000.000.
In addition, after fermentation synthesis, for example, heat treatment or γ
The molecular weight is reduced by post-treatment such as radiation treatment, e.g.
000 to about 10.000 can also be suitably used.

The biodegradable composition applied to the packaging material of the present invention contains such a polyhydroxyalkanoate or a copolymer thereof as a main component, and contains a lipid compound of 0.01 to 60%.
% by weight.

Lipid compounds to be blended include monoglycerides, diglycerides, triglycerides, monocarboxylic acid esters,
Dicarboxylic acid monoester, dicarboxylic acid diester,
Dialcohol monoester, dialcohol diester,
Examples include one or more of tricarboxylic acid monoester, tricarboxylic acid diester, tricarboxylic acid triester, etc. 6 Examples of glycerides include fatty acid glycerin esters having 2 to 18 carbon atoms; specifically, examples of monoglycerides include glycerol monoacetate, glycerol; Monopropionate, glycerol monobutyrate, glycerol monolaurate, glycerol monomyristate, glyceryl monopalmitate, glycerol monostearate, etc.; diglycerides include glycerol diacetate, glycerol dipropionate, glycerol diacetate, glycerol Dilaurate, glycerol simiristate, glycerol dipalmitate, glycerol distearate, etc.; triglycerides include glycerol triacetate, glycerol tribionate, glycerol tributyrate, glycerol trilaurate, glycerol tripalmitate, glycerol trimylate; state,
Various suitable examples include glycerol tristearate and the like.

Furthermore, as carboxylic acid esters, carbon atoms of 2 to 3
Examples include esters consisting of 0 carboxylic acid and an alkyl having 2 to 30 carbon atoms. Specifically, saturated or unsaturated monocarboxylic acid esters include 〇-amyl acetate, ethyl propionate, methyl caproate, Ethyl crotonate, n-butyl oleate, etc.; Saturated or unsaturated dicarboxylic acid monoesters include monomethyl sebacate, mono-n-butyl maleate, monoethyl terephthalate, etc.; Saturated or unsaturated dicarboxylic acids As a diester,
Dimethyl sebacate, dimethyl terephthalate, di(2-ethylhexyl) phthalate, di-n-octyl phthalate, etc.; Tricarboxylic acid monoesters include monomethyl trinalate, mono-butyl trimellidate, etc.; tricarboxylic acid diesters Examples of nitricarboxylic acid triesters include trimethyl trimelate, tributyl trimeldate, etc.; and dialcohol monoesters include ethylene glycol monostearate, propylene glycol monostearate, etc. Preferred examples of the di-alcohol diester include ethylene glycol distearate, propylene glycol distearate, and the like.

In addition, these lipid compounds may be liquid or solid at room temperature.

In the biodegradable composition applied to the packaging material of the present invention,
These lipid compounds act as a kind of plasticizing or softening agent for polyhydroxyalkanoates.
Furthermore, some of them will lower the melting point and glass transition temperature of the polyhydroxyalkanoate.

Therefore, the biodegradable composition applied to the present invention has significantly improved flexibility at the operating temperature (for example, room temperature) compared to polyhydroxyalkanoate or its copolymer, and some of it is Since the heating temperature during heating can be lowered, unnecessary thermal decomposition and the like can be prevented from occurring.
Moreover, these lipid compounds are generally inexpensive, so they are economically advantageous.

In the biodegradable material applied to the packaging material of the present invention,
The content of such lipid compounds is 0.01-60% by weight
, preferably 1 to 40% by weight. If the content of the lipid compound is less than 0.01% by weight, the effect of improving the physical properties of the polyhydroxyalkanoate will not be sufficiently obtained, and if the content exceeds 60% by weight, the lipid compound will separate into layers. etc., resulting in a decrease in the physical properties of the resulting packaging material.

The polyhydroxyalkanoate and these lipid compounds can be mixed by dissolving them in an appropriate solvent such as chloroform or dichloromethane, mixing them, and then evaporating the solvent, or by mechanically mixing them using a mixing roll or a Banbury mixer. It is possible to apply a method of mixing the two.

The biodegradable composition applied to the packaging material of the present invention is described in detail in Japanese Patent Application No. 76585/1999 filed by the present applicant.

In addition to such a biodegradable composition, the packaging material of the present invention contains
It contains various resins as molding materials. By having such a structure, the packaging material of the present invention not only has the characteristics of the biodegradable composition, but also has performance depending on the application for which the packaging material is required, such as tensile strength, elongation at break, tear strength, It suitably satisfies various performance requirements depending on the usage of packaging materials, such as heat resistance, gas barrier properties, solvent resistance, chemical resistance, water resistance, printability, and high-speed sealing properties, making it suitable for use as packaging materials. can be made wider.

There are no particular limitations on the applicable resin, and various known resins can be applied depending on the desired performance, but specifically, polyvinyl chloride, low density or high density polyethylene, linear low density polyethylene , polypropylene, polystyrene, ionomer, polyvinyl acetate, polyvinyl alcohol, polyacrylic acid, polyacrylic ester, polymethacrylic acid, polymethacrylic ester, polyvinylidene chloride, polyvinylidene fluoride, nylon, polyester, polyethylene terephthalate, polyurethane, etc. , copolymers and mixtures containing these are preferred examples.

Here, the resin to be mixed into the biodegradable composition described above can be appropriately selected depending on the desired properties to impart the properties of this resin, but for example, by applying polyethylene terephthalate, high speed Heat-sealability, processability, durability, and printability can be imparted, and by applying an ionomer, high-speed heat-sealability, processability, etc. can be imparted, and polyvinylidene chloride, polyvinyl alcohol, By applying a saponified ethylene-vinyl acetate copolymer or the like, gas barrier properties can be imparted.

The amount of resin in the packaging material of the invention is 1 to 70% by weight. If the amount of resin is less than 1% by weight, a sufficient effect of modifying physical properties cannot be obtained, and if it exceeds 70% by weight, good biodegradability cannot be exhibited. In addition, by setting the amount of resin to 2 to 30% by weight, more preferable results can be obtained in terms of being able to exhibit both the properties of improving physical properties and maintaining biodegradability.

In the packaging material of the present invention, the biodegradable composition and resin are:
They may be mixed and applied as a composite material, or both may be laminated and applied as a laminate material. Furthermore, a biodegradable material and a resin may be bonded together, and at least a portion of the material may be made of either one.

There are no particular limitations on the method of mixing a biodegradable composition and a resin to form a composite material, and since the above-mentioned biodegradable composition is soluble in solvents such as chloroform and dichloromethane, both are mixed in an appropriate solvent. A method of dissolving and mixing the two and then evaporating the solvent, a method of mechanically mixing using a mixing roll or a Banbury mixer, a method of triblending the two and directly mixing them through a heating router of a confinement molding machine or extruder methods etc. are applicable. In this case, the biodegradable composition and the resin to be applied do not need to be used alone, and either one or more of them may be used.

In addition, in the case of laminated materials, a lamination method in which one of the biodegradable compositions and resins is formed into a desired shape such as a sheet or a bottle, and then a coating of depping or casting is applied, a water-based Alternatively, any known method for laminating resin materials can be applied, such as wet lamination in which a solvent-based adhesive is applied, lamination by heating a film, etc., or dry lamination in which the adhesive is dried and then laminated.

Furthermore, since this biodegradable material is soluble in some organic solvents such as chloroform, processing by dip coating, roll coating, etc. can also be suitably applied, for example, when it is desired to form a laminated material with various resins.

In addition, the number of laminated layers is not limited to two layers, and may be laminated with three or more layers. In this case, the multiple layers may be made of biodegradable material or resin. or both.

In the packaging material of the present invention, in addition to these various resins, various additives such as fillers, dyes, pigments, lubricants, antioxidants, and heat stabilizers may be mixed as necessary. Good too. In this case, it is preferable that the total amount of the additive and the resin is 1 to 70% by weight.

The packaging material of the present invention is basically molded from the biodegradable composition and resin as described above.

As mentioned above, the packaging material in the present invention includes all materials used to wrap at least a portion of a certain item or to fill a certain item. Therefore, there are no limitations on its shape (for example, a film or sheet that envelops at least a portion of the object to be packaged; a bag-like or spherical shape that encloses at least a portion of the object to be packaged). Concave shapes such as box-like, cylindrical, cup-like, and bottom-like with one side closed, and their lids; Bottle-like, hollow column-shaped, and their lids that are especially suitable for filling liquids, etc.; Various shapes can be applied depending on the shape and material of the object to be packaged, such as band-like, string-like, thread-like shapes that are used for bundling bottles, cans, etc.; and composite shapes of these.

Furthermore, there are no limitations to the objects to be packaged to which the packaging material of the present invention can be applied, and all objects are covered, regardless of whether they are liquids, gases, or various structures. Specifically, needles, syringes,
Catheters, infusion sets, blood transfusion sets, infusion bags, blood circuits, pharmaceuticals in the form of granules or tablets, testing reagents, artificial organs such as dialysis machines, medical products such as electronic thermometers, electronic blood pressure monitors, and other medical products, fresh or processed. Examples include foods, various beverages, various daily necessities such as clothing and detergents, and various other industrial products.

The biodegradable composition applied to the packaging material of the present invention has thermoplasticity. Therefore, if the resin to be applied is a thermoplastic resin, any resin processing method normally applied to thermoplastic resins can be applied as the molding method of the present invention.

Preferred examples include extrusion molding, particularly extrusion molding using a T-die or inflation; various injection molding; blow molding, particularly extrusion blow molding or injection blow molding; powder molding; calendar molding; casting method; etc. . Moreover, these moldings may be performed while heating. Furthermore, it is formed into a sheet by extrusion molding, calendar molding, etc., and this sheet is then used for vacuum forming, press molding, laminated press molding, or dissolved in chloroform and coated to form a structure or laminate in the desired shape. (process). It may also be a foam.

The packaging material of the present invention is not limited to those that are integrally molded by the above-mentioned various molding methods; for example, two sheets or films obtained by extrusion molding using a T-die are heat-sealed or high-frequency sealed. (Also, when molding a bottle, etc., the main body and bottom are molded separately and molded integrally by methods such as heat sealing, high frequency sealing, ultrasonic sealing, etc.) In this case, the molding methods of the individual members may be the same or different.

It goes without saying that the surface of the packaging material of the present invention may be colored, printed, etc. during or after molding, or before processing.

The packaging material of the present invention molded in this way can be used for medical products,
When it is necessary to disinfect or sterilize the material, such as when it is used as a food packaging material, various known disinfection and sterilization methods can be applied. For example, sterilization methods include autoclave sterilization, ultraviolet sterilization, ionizing radiation sterilization such as gamma rays and electron beams, gas sterilization using ethylene oxide, etc.
Preferred examples of the disinfection method include chemical disinfection using cresol, disinfectant ethanol, and the like.

<Example> Hereinafter, the present invention will be explained in more detail by giving specific examples of the packaging material of the present invention.

[Example 1] Poly(3-hydroxybutyrate) (Mw=670
．． 000 (manufactured by Aldrich) and glycerol triacetate (manufactured by Tokyo Kasei) were dissolved and mixed in chloroform at a weight ratio of 80:20, and then the chloroform was evaporated to produce a film with a thickness of 0.2 mm. .

A composite film (hereinafter referred to as film) was obtained by laminating and adhering an ionomer (manufactured by DuPont Mitsui Polychemicals, Himilan) with a thickness of 50 LLm to this film using an epoxy adhesive (manufactured by Ciba Geigy, Araldite). Ta. Note that no trouble occurred during molding, and the obtained film was highly flexible.

When an attempt was made to seal the ionomer layer sides of the two obtained films with a heat sealer, the temperature was approximately 140°C.
, 02 seconds and cooling time of 02 seconds.

Using this sheet, a bag 10 as shown in FIG. 1 was made by heat sealing, and a 500 m
An infusion bag 12 containing β physiological saline (Terumo Saline, manufactured by Terumo ■) was placed and sealed with a heat seal.

This bag 10 was wrapped in cardboard and left in the trunk of a car used for commuting for two weeks, but no problems such as tearing of the bag 10 occurred. In addition, the bag maintained its flexibility and was in a state where it could withstand continued use.

After that, the infusion bag 12 was taken out and only the bag body 10 was buried in the soil in Nakai-cho, Ashigarakami-gun, Kanagawa Prefecture.When it was dug up 6 months later, some powdery sheet pieces were found, but it had completely decomposed. It did not retain its original shape.

[Comparative Example 1] In the same manner as in Example 1, poly(3-hydroxybutyrate) and glycerol acetate were mixed at a weight ratio of 80:20 to produce a 0.2 mm film.

When an attempt was made to heat seal two sheets of this film using a heat sealer, it required 170° C. for 0.5 seconds and cooling for 2 seconds, and the sealing performance was slightly inferior to that of the sheet of Example 1.

[Example 2] Poly(3-hydroxybutyrate) (i; 670.00
0 Aldrich), glycerol triacetate (Tokyo Kasei), and powdered polyethylene terephthalate resin (Eastman Kodak, PETG).
6763) in chloroform at a weight ratio of 80:20:30, and then the chloroform was evaporated to form a sheet with a thickness of 2 mm, which was cut with a cutter to form pellets. This pellet was tri-blended with 1 wt % of an antioxidant (Irganox 1010, manufactured by Ciba Geigy), and was then subjected to T-die extrusion molding using a blast mill (manufactured by Toyo Seiki Seisakusho ■) at a nozzle and die temperature of 180°C. ,
A film with a thickness of 0.6 mm was produced. Note that no trouble occurred during molding, and the obtained film was highly flexible.

Rubber No. 3 dumbbell (JISK6301) with this film
A tensile test was conducted at a tensile speed of 20 mm/min and a temperature of 23°C. As a result, the breaking strength was 29
It was MPa.

A bag similar to that in Example 1 was made using this sheet, and similar experiments were conducted.
After several months, some powdery sheet fragments were observed in the bag, but it had completely disintegrated and remained in its original shape.

[Comparative Example 2] A film with a thickness of 0.6 mm was produced in exactly the same manner as in Example 2, except that the polyethylene terephthalate resin was not added and the T-die extrusion temperature was 160°C.

The tensile strength of this film was measured in exactly the same manner as in Example 2, and was found to be 20 MPa.

[Example 3] 3-hydroxybutyrate/3-hydroxyvalerate copolymer (3-hydroxyvalerate component 23moj2
% Aldrich) and glycerol trilaurate (manufactured by Tokyo Kasei) in chloroform at a weight ratio of 80:20, and then the chloroform was evaporated to form a film with a thickness of 0.2 mm. was created.

One side of the sheet was coated with polyvinylidene chloride latex (manufactured by Kureha Kagaku Kogyo ■, Frehalon), and then dried at room temperature to obtain a sheet with a thickness of 0.3 mm.

Regarding this sheet, the oxygen permeation amount and water vapor permeation amount were measured using a gas permeation amount measurement device @ Lloo and water vapor permeation amount measurement device L80 manufactured by Lyssy, and the oxygen permeation amount was 5 cm”/m2dayatm (30°C).
, water vapor permeation amount is 1 g/m"day (40℃, 90
%RH).

A bag similar to that in Example 1 was made using this sheet, and similar experiments were conducted.
Around the circumference, the bag had disassembled and no longer retained its original shape.

[Comparative Example 3] A film with a thickness of 0.2 m11+ was obtained in the same manner as in Example 3, except that polyvinylidene chloride latex was not coated.

When the oxygen permeation amount and water vapor permeation amount of this film were measured in the same manner as in Example 3, the oxygen permeation amount was 1.
4 cm3/m"-day-atm (30℃), water vapor permeation rate is 7 g/m"-day (40℃, 90% R
H).

From the above results, the effects of the present invention are clear.

<Effects of the Invention> As explained in detail above, the packaging material of the present invention has excellent biodegradability by using a predetermined resin composition having good biodegradability as a material, and does not require landfilling after use. If it is disposed of in the environment, such as in the ocean or in activated sludge, it will decompose in a short time and will not cause environmental pollution. Moreover, it has excellent processability, economic efficiency, etc., and also has performance that meets the requirements of the packaging material, such as tensile strength, elongation at break, tear strength, heat resistance, gas barrier properties, etc.
It satisfies various performance requirements depending on the usage of packaging materials, such as solvent resistance, chemical resistance, water resistance, durability, printability, high-speed sealing performance, etc., making it more suitable for use as a packaging material. It can be wide.

Explanation of symbols 10... bag body, 12... Export night bag

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing an example of a bag according to the packaging material of the present invention.

Claims (5)

[Claims] (1) A biodegradable composition containing polyhydroxyalkanoate, a copolymer thereof, or a mixture thereof as a main component and containing 0.01 to 60% by weight of a lipid compound, and 1 to 70% by weight of a lipid compound. A packaging material characterized by being molded from resin. (2) The polyhydroxyalkanoate is poly(3-
The packaging material according to claim 1, wherein the packaging material is a hydroxyalkanoate. (3) The polyhydroxyalkanoate is poly(4-
The packaging material according to claim 1, wherein the packaging material is a hydroxyalkanoate. (4) The polyhydroxyalkanoate is poly(5-
The packaging material according to claim 1, wherein the packaging material is a hydroxyalkanoate. (5) Film-like, sheet-like, cylindrical, box-like, bag-like, hollow cylinder-like, cup-like, concave-shaped, bottle-like, string-like, band-like, spherical, net-like, or two or more of these shapes. The packaging material according to any one of claims 1 to 4, which has a composite shape.