JPH11278451A - Degradable resin blister pack or tray - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make excellent in biodegradability in natural environments and also to improve moldability, adaptability in distribution, mechanical strength or the like by molding a packaging container of a lactone resin or a composition containing a lactone resin which has been subjected to irradiation treatment. SOLUTION: A packaging container is formed of a composition constituting a lactone-containing resin with at least lactone resin subjected to irradiation. The irradiation may be performed for a single lactone resin, a mixture of the lactone resin and another biodegradable resin or with at least resin additive blended to the lactone containing resin before, during or after molding. By irradiation a crosslinking structure can be formed in the lactone resin. As a result, biodegradability is improved, and further, mechanical characteristics such as tensile strength, tensile elongation and tear strength are also improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disposable biodegradable resin blister pack or tray. More specifically, the present invention relates to a biodegradable resin blister pack or tray which uses a lactone resin which has been subjected to radiation irradiation treatment, has biodegradability in a natural environment, and is excellent in strength, transparency and the like.

[0002]

2. Description of the Related Art Conventionally, polyethylene and polypropylene have been used as containers and lids for plastic blister packs.
Resins such as polyethylene terephthalate, polyvinyl chloride, and ethylene-vinyl acetate copolymer are used. However, although blister packs made from such resins are excellent in moldability, transparency, and water resistance, they increase the bulk of garbage when discarded, and become brittle under natural environments.
Since it has almost no degradability or biodegradability, it remains semi-permanently even if buried. In addition, there is a problem that the landscape is impaired if left abandoned on the ground, and the living environment of other living things may be destroyed.

[0003] Further, a copolymer of polyhydroxybutyrate and polyhydroxyvalerate which is effective for decomposability,
Containers molded from starch-based degradable plastics have been developed, but are not preferred because they have low strength and rigidity, and may cause molds during normal use and storage. Further, the blister pack made of these materials has low transparency in both the container and the lid as compared with the general-purpose synthetic resin, so that it is difficult to confirm the contents filled in the container, which is not preferable for this use. . Polylactic acid or copolymers of lactic acid and other hydroxycarboxylic acids have also been developed as polymers with good biodegradability, but are not yet completed as a material for blister packs in terms of moldability, suitability for distribution, mechanical strength, etc. .

[0004]

SUMMARY OF THE INVENTION Accordingly, in view of the present situation relating to the above-mentioned blister packs or materials suitable for the same, the present invention is not only excellent in biodegradability in a natural environment, but also excellent in moldability, distribution suitability, and mechanical properties. It is an object of the present invention to obtain a blister pack that is practical in various points such as a target strength.

[0005]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve the above-mentioned problems, and as a result, the lactone resin to which poly-ε-caprolactone belongs or a composition containing the lactone resin is subjected to a specific irradiation treatment. Thereby, the knowledge that a cross-linked structure can be formed in the lactone resin was obtained, and a blister pack sheet using such a treated lactone resin or a composition thereof was successfully obtained. completed.

That is, the gist of the present invention is as follows.
A first aspect of the present invention is a biodegradable resin blister pack or tray formed by molding a biodegradable resin composition containing a lactone resin alone or a lactone resin into a packaging container. Alternatively, the present invention relates to a blister pack or a tray made of a degradable resin, wherein the component lactone resin of the tray has been subjected to radiation irradiation alone or together with at least one other component. A second aspect of the present invention relates to the degradable resin blister pack or tray according to the first aspect of the present invention, wherein the other biodegradable resin is a synthetic and / or natural polymer. A third aspect of the present invention is the degradable resin-made blister pack or tray according to the second aspect of the present invention, wherein the synthetic polymer is an aliphatic polyester, a biodegradable cellulose ester, a polypeptide, a polyvinyl alcohol, or a mixture thereof. It is about. A fourth aspect of the present invention is that the natural polymer is
The present invention relates to a blister pack or tray made of a degradable resin according to the second aspect of the present invention, which is starch, cellulose, carrageenan, chitin / chitosan, natural linear polyester resin, or a mixture thereof. The fifth of the present invention
Furthermore, photodegradation, biodegradation accelerator, heat stabilizer, lubricant, colorant, flame retardant, water resistant agent, autoxidizer, ultraviolet stabilizer,
The degradable resin blister pack or tray according to any one of the first to fourth aspects of the present invention, to which a crosslinking agent, an antibacterial agent, an antioxidant, a deodorant, a nucleating agent, an antiblocking agent or a mixture thereof is added. Things. Sixth Embodiment
Means that the tensile elastic modulus (JIS K7127) of the sheet constituting the blister pack or tray is 100 to 800 N /
The degradable resin blister pack or the tray according to any one of claims 1 to 5, wherein the blister pack has a diameter of ² mm or an impact strength (JIS K7211) of 10 to 50 kg · cm. A seventh aspect of the present invention is that the glass transition point of the resin constituting the blister pack or the tray is −60 to 20 ° C.
The blister pack or tray made of a degradable resin according to any one of the first to sixth aspects of the present invention. An eighth aspect of the present invention relates to the blister pack or tray made of a degradable resin according to any one of the first to seventh aspects, wherein the lactone resin is poly-ε-caprolactone.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The lactone resin used for thin-walled molded articles (hereinafter, referred to as blister packs and the like) such as biodegradable resin blister packs, trays, cups, and packaging boxes according to the present invention is ε-caprolactone, 4-methylcaprolactone. , 3,5,5-trimethylcaprolactone, 3,
Homopolymers of various methylated caprolactones such as 3,5-trimethylcaprolactone, β-propiolactone, γ-butyrolactone, δ-valerolactone, enantholactone, copolymers of two or more of these monomers, homopolymers thereof Or a mixture of copolymers. The lactone resin may be copolymerized with a lactone monomer and a monomer other than the lactone monomer, for example, an aliphatic hydroxycarboxylic acid such as lactic acid, hydroxypropionic acid, or hydroxybutyric acid; an aliphatic diol exemplified by an aliphatic polyester described below. And aliphatic dicarboxylic acids. In particular, those which do not soften at room temperature are preferable, and from this viewpoint, poly-ε-caprolactone having a high molecular weight and a melting point of 60 ° C. or more and easily obtaining stable performance (hereinafter sometimes referred to as PCL or polycaprolactone) is preferable. It is. On the other hand, poly-.epsilon.-caprolactone having a glass transition point of -60.degree. C. is suitable for molding into a thin container having large irregularities.

Hereinafter, the lactone resin according to the present invention will be described using polycaprolactone as a typical example. The number average molecular weight of the polycaprolactone before irradiation is preferably from 10,000 to 1,000,000, and particularly preferably from 100,000 to 500,000 from the viewpoint of efficient crosslinking. Polycaprolactone having the above molecular weight has a relative viscosity of 1.15 to JIS K6726.
2.80, particularly preferably 1.50.
~ 2.80.

The lactone-containing resin (c) used in the present invention is a lactone resin (a) alone or a mixture of the lactone resin (a) and another biodegradable resin (b). As the other biodegradable resin, a synthetic and / or natural polymer is used. Examples of the synthetic polymer include an aliphatic polyester, a polyamide, a polyamide ester, a biodegradable cellulose ester, a polypeptide, a polyvinyl alcohol, an ethylene-vinyl acetate copolymer, and a mixture thereof. The synthetic aliphatic polyester resin is a polyester resin other than the lactone resin, and is an aliphatic polyester resin obtained by a condensation polymerization system. Hereinafter, the synthetic aliphatic polyester resin is simply referred to as an aliphatic polyester resin, and in the case of a naturally occurring resin, this is clearly indicated. As the aliphatic polyester resin,
Biodegradable polyester resins such as synthetic polylactic acid, polyethylene succinate and polybutylene succinate (such as low molecular weight aliphatic dicarboxylic acid and low molecular weight aliphatic resin represented by Bionole of Showa Polymer Co., Ltd.) Examples thereof include polyester resins synthesized from diols), JP-A-9-235360, and JP-A-9-235360.
And terpolymer aliphatic polyesters described in JP-A-233956, and lactic acid-hydroxycarboxylic acid copolymers described in JP-A-7-177826. The aliphatic polyester resin may be a resin obtained by adding an aliphatic isocyanate such as hexamethylene diisocyanate to a low-molecular-weight aliphatic polyester and reacting the aliphatic polyester with a urethane bond to increase the molecular weight. Examples of the biodegradable cellulose ester include organic acid esters such as cellulose acetate, cellulose butyrate, and cellulose propionate; inorganic acid esters such as cellulose nitrate, cellulose sulfate, and cellulose phosphate; cellulose acetate butyrate, cellulose acetate phthalate, and nitric acid. Hybrid esters such as cellulose acetate can be exemplified. These cellulose esters are
They can be used alone or in combination of two or more. Among these cellulose esters, organic acid esters, particularly cellulose acetate, are preferred. Examples of the polypeptide include polyamino acids such as polyglutamic acid and polymethylglutamic acid, and polyamide esters. Examples of polyamide esters include resins synthesized from ε-caprolactone and ε-caprolactam. As the synthetic polymer, for example, taking an aliphatic polyester resin as an example,
Number average molecular weight is 2 in terms of standard polystyrene by GPC
0000 or more and 200,000 or less, preferably 40,
More than 000 can be used.

As natural polymers, starch, cellulose,
Paper, pulp, carrageenan, chitin / chitosan, natural linear polyester resin, or a mixture thereof. Examples of the starch include raw starch, processed starch, and a mixture thereof. As raw starch, corn starch, horsebell chopsticks starch, sweet potato starch, wheat starch, cassava starch, sago starch, tapioca starch, rice starch, bean starch,
Kudzu starch, bracken starch, lotus starch, Japanese cinnamon starch and the like, and the modified starches include physically modified starches (α-starch, fractionated amylose, wet heat-treated starch, etc.), and enzyme-modified starches (hydrolyzed dextrin, enzyme-decomposed dextrin). , Amylose, etc.), chemically degraded starch (acid-treated starch, hypochlorite oxidized starch, dialdehyde starch, etc.), and chemically modified starch derivatives (esterified starch, etherified starch, cationized starch, cross-linked starch, etc.). No. Among the above, as the esterified starch, acetate-starch, succinate-starch, nitrate-starch, phosphate-starch, urea-phosphate-starch, xanthate-starch, acetoacetate-starch Etc .; etherified starch such as allyl etherified starch, methyl etherified starch, carboxymethyl etherified starch, hydroxyethyl etherified starch and hydroxypropyl etherified starch; etc .; cationized starch includes starch and 2-diethylaminoethyl chloride And the reaction product of starch and 2,3-epoxypropyltrimethylammonium chloride; crosslinked starch includes formaldehyde crosslinked starch;
Epichlorohydrin cross-linked starch, phosphoric acid cross-linked starch, acrolein cross-linked starch and the like.

In the present invention, the lactone-containing resin composition comprises a lactone-containing resin and a resin additive. Resin additives include plasticizers, heat stabilizers, lubricants, antiblocking agents, nucleating agents, photolytic agents, biodegradation accelerators, antioxidants, ultraviolet stabilizers, antistatic agents, flame retardants, droplets, antibacterial agents Agents, deodorants, fillers, colorants or mixtures thereof.

Examples of the plasticizer include aliphatic dibasic acid esters, phthalic acid esters, hydroxy polycarboxylic acid esters, polyester plasticizers, fatty acid esters, epoxy plasticizers, and mixtures thereof. Specifically, di-2-ethylhexyl phthalate (DOP), dibutyl phthalate (DBP), diisodecyl phthalate (D
Phthalic acid esters such as IDP), adipic acid-di-2-
Adipates such as ethylhexyl (DOA) and diisodecyl adipate (DIDA), azelaic acid-
Azelaic acid esters such as di-2-ethylhexyl (DOZ), tri-2-ethylhexyl acetylcitrate,
Polyester plasticizers such as hydroxy polyvalent carboxylate esters such as acetyl tributyl citrate and polypropylene glycol adipate esters, which are used alone or in a mixture of two or more. The addition amount of these plasticizers varies depending on the application, but is generally 3 to 30 parts by weight, based on 100 parts by weight of the lactone-containing resin.
Particularly, the range of 5 to 15 parts by weight is preferable. If it is less than 3 parts by weight, elongation at break and impact strength will be low, and if it exceeds 30 parts by weight, the strength at break and impact strength may be reduced.

As the heat stabilizer used in the present invention, there is an aliphatic carboxylate. As the aliphatic carboxylic acid, an aliphatic hydroxycarboxylic acid is particularly preferred. As the aliphatic hydroxycarboxylic acid, naturally occurring ones such as lactic acid and hydroxybutyric acid are preferable. Examples of the salt include salts of sodium, calcium, aluminum, barium, magnesium, manganese, iron, zinc, lead, silver, copper, and the like. These can be used as one kind or as a mixture of two or more kinds. The amount of lactone-containing resin 1
The range is 0.5 to 10 parts by weight with respect to 00 parts by weight. When the heat stabilizer is used within the above range, the impact strength (Izod impact value) is improved, and there is an effect that variations in elongation at break, strength at break, and impact strength are reduced.

The lubricant used in the present invention includes an internal lubricant,
Those generally used as an external lubricant can be used. For example, fatty acid esters, hydrocarbon resins, paraffins, higher fatty acids, oxy fatty acids, fatty acid amides, alkylene bis fatty acid amides, aliphatic ketones, fatty acid lower alcohol esters, fatty acid polyhydric alcohol esters, fatty acid polyglycol esters, fatty alcohols, Examples include a hydric alcohol, polyglycol, polychrycerol, metal soap, modified silicone or a mixture thereof. Preferably, fatty acid esters, hydrocarbon resins and the like are used. When selecting a lubricant, it is necessary to select a lubricant whose melting point is lower than the melting point of the lactone resin or other biodegradable resin. For example, considering the melting point of the aliphatic polyester resin, the fatty acid amide is 160 ° C.
The following fatty acid amides are selected. The compounding amount is such that 0.05 to 5 parts by weight of a lubricant is added to 100 parts by weight of the lactone-containing resin. If the amount is less than 0.05 part by weight, the effect is not sufficient, and if it exceeds 5 parts by weight, the physical properties deteriorate. From the viewpoint of preventing environmental pollution, ethylene bisstearic acid amide, stearic acid amide, oleic acid amide, and erucic acid amide, which are highly safe and registered with the FDA (US Food and Drug Administration), are preferred.

Examples of the photodegradation accelerator include benzophenones such as benzoins, benzoin alkyl ethers, benzophenone and 4,4-bis (dimethylamino) benzophenone and derivatives thereof; acetophenone,
Acetophenones such as α, α-diethoxyacetophenone and derivatives thereof; quinones; thioxanthones; photoexciting materials such as phthalocyanine, anatase-type titanium oxide, ethylene-carbon oxide copolymer, sensitization of aromatic ketones with metal salts And the like. These photolysis accelerators are
One type or two or more types can be used in combination.

The biodegradation promoter includes, for example, oxo acids (eg, oxo acids having about 2 to 6 carbon atoms such as glycolic acid, lactic acid, citric acid, tartaric acid, malic acid, etc.) and saturated dicarboxylic acids (eg, Organic acids such as lower saturated dicarboxylic acids having about 2 to 6 carbon atoms such as oxalic acid, malonic acid, succinic acid, succinic anhydride, glutaric acid and the like; these organic acids and alcohols having about 1 to 4 carbon atoms; Lower alkyl esters. Preferred biodegradation promoters include organic acids having about 2 to 6 carbon atoms, such as citric acid, tartaric acid, and malic acid, and coconut shell activated carbon. One or more of these biodegradation accelerators can be used in combination.

In the present invention, at least the lactone resin constituting the lactone-containing resin has been subjected to a predetermined irradiation treatment. In the present invention, in the state of a lactone resin alone, or in a state of a mixture of a lactone resin and another biodegradable resin, or in a state where at least one resin additive is blended with a lactone-containing resin, before molding, during molding Alternatively, irradiation may be performed after molding. Further, the shape may be a powder, a pellet, a molding state, or a product state. Therefore, in the present invention, the lactone resin alone is subjected to a predetermined irradiation treatment in advance, and a synthetic aliphatic polyester resin is mixed with the lactone resin, or a resin composition obtained by further adding a fatty acid amide or the like, and synthesized with the lactone resin. A resin composition obtained by mixing an aliphatic polyester resin or a fatty acid amide and performing the same radiation irradiation treatment and then mixing the remaining components, a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide, and then performing the above irradiation treatment Are also included in the constituent resin compositions such as blister packs. Further, as a mode in which the three components are mixed and then subjected to the radiation irradiation treatment, a mode of irradiating a composition (for example, a strand for pellet manufacturing) at the time of manufacturing a pellet for molding may be irradiated during molding. The embodiment also includes an embodiment in which the molded article is irradiated.
Further, there is also included a mode of irradiating with a low dose first and irradiating with a high dose at a later stage. For example, at the pellet stage, the gel fraction becomes 0.01 to 10%, preferably 0.05 to 1.0%. Irradiation can be performed so as to be 1 to 90%, preferably 10 to 90% during or after molding.
This results in a higher melting point than unirradiated ones,
Irradiation can be performed again while maintaining the shape at a higher temperature, and crosslinking occurs with a high probability, and heat resistance is improved. The gel fraction is 0.01-10%, preferably 0.05-1.
By irradiating so as to be 0%, crosslinking occurs and the melting point increases, tensile strength and tear strength are improved, releasability from a mold and roll adhesion are reduced, and transparency is increased.

The radiation source used in the radiation irradiation treatment according to the present invention includes α-rays, β-rays, γ-rays, X-rays, electron beams,
Ultraviolet rays and the like can be used, but γ-rays, electron beams, and X-rays from cobalt 60 are more preferable. Among them, γ-rays, electron beam irradiation treatment using an electron accelerator is useful for introducing a bridge structure of a polymer material. Most convenient.

The irradiation amount is determined using a gel fraction of a lactone resin as a measure for introducing a crosslinked structure of a polymer material as one measure. When irradiating the lactone resin before molding, the gel fraction is 0.05 to 10% in consideration of moldability.
And preferably about 0.1 to 1%. When irradiating a molded article, the gel fraction of the lactone resin can be as high as about 90%. When the gel fraction is set to 10% or more, since the crosslinking occurs mainly in the non-crystalline region of the polymer material, in the irradiation treatment near room temperature, for example, 200 kGy
In the process near the melting point, a large number of voids are generated and the strength tends to decrease. Therefore, in such a case, the lactone resin is cooled to a temperature not lower than the melting point (60 ° C. for polycaprolactone) and not crystallization after melting (50 to 35 ° C. for polycaprolactone). By performing the above treatment in this state, a gel with a very high gel fraction can be obtained at a low dose. As described above, one of the conditions for the radiation irradiation treatment was specified as “a state that does not lead to crystallization after melting”. Occurs in the non-crystal part, so that the non-crystal state is dominant. If the degree of crystallinity is lower than in the room temperature state, there is a corresponding irradiation effect.
In addition, not only the treatment with the lactone resin alone, but also the treatment with the above various compositions comprising other components, it is sufficient to consider only the molten state of the lactone resin component. Of course, it is also possible to irradiate up to a high gel fraction without melting.

As a result of observing the effect of the radiation treatment of the lactone resin in the present invention, the gel fraction and MI of the degree of crosslinking were measured.
When kGy is reached, the effect starts to appear, and the gel fraction is 100.
A sharp rise was seen at kGy, and MI was 60 kGy.
, And tend to be stable at higher doses. Regarding biodegradability, when measured in sludge, the higher the irradiation dose, the higher the decomposition rate,
Biodegradation was started by immersion for 4 to 5 days, and after about 10 days, a result of a decomposition rate of 50% was obtained. In addition, improvements in mechanical properties (tensile strength, tensile elongation, tear strength, impact strength) and anti-blocking properties of the film against nip rolls were also observed.

The resin constituting the blister pack of the present invention preferably has a glass transition point of -60 to 20 ° C. Further, the tensile elastic modulus (JIS K7127) of the resin sheet constituting the blister pack or the like is 100 to 800N.
/ Mm ² or impact strength (JIS K7211)
Is preferably 10 to 50 kg · cm.

In the present invention, various molded articles can be obtained by molding a lactone-containing resin or a lactone-containing resin composition. In the middle of the molding, a preform such as a sheet or a parison can be used. Examples of the forming method include a vacuum forming method, a pressure forming method, and a vacuum / pressure forming method.

The thickness of the blister pack or the like according to the present invention is not always the same between the container and the lid.
Usually, it is preferable to make it thicker. The respective thicknesses of the blister packs and the like are appropriately selected depending on the application, but are usually used, and the thickness which can obtain a crosslinking effect by irradiation with radiation is 10 to 1000.
μm is preferred, and 20 to 500 μm is more preferred.

[0024]

EXAMPLES The present invention will be described below in more detail with reference to examples, but the present invention is not limited to these examples. In the Examples, “%” and “parts” are based on weight unless otherwise specified. The melt index (MI) is a value indicating the flow characteristics under a load of 2160 g at 190 ° C. First, in addition to the above-described effects of the radiation irradiation treatment of polycaprolactone of the lactone resin according to the present invention, a more specific description will be given using reference examples.

REFERENCE EXAMPLE 1 Polycaprolactone pellets (melt index 2.57 g / 10 min) were heated to a melting point or higher, then cooled to 50 ° C., and while being in an amorphous state, an electron beam was irradiated as radiation at 60 kGy and 160 kGy. Upon irradiation, the resulting treated pellets had a melt index of 0.05 g / 10 min (gel fraction 60 described below).
%) And 0.03 g / 10 min (gel fraction 80%). The untreated pellets and treated pellets were placed in an urban sewage sludge environment at 25 ° C. according to JIS K6950,
They were subjected to a 4-week biodegradability test. As a result, the decomposition rate of the non-irradiated product was 55%, while that of the irradiated product was 86.2% and 77.2%, respectively. Further, the irradiated product was formed into a sheet by a hot press at 200 ° C., and a biodegradability test was similarly performed on the pulverized sample. as a result,
The decomposition rates were 87.0% and 87.8%, respectively. The same test results were obtained by changing the irradiation type from electron beam to gamma ray.

Reference Example 2 The polycaprolactone used in Reference Example 1 was irradiated at room temperature with an electron beam irradiation amount of 15 kGy. Processed pellets (melt index is 1.0
g / 10 min, gel fraction 0.2%) was extruded with an extruder (resin temperature 150 ° C.) provided with a 40 mmφ T-die to obtain a sheet having a thickness of about 270 μm. The resulting sheet was subjected to a tear test, an impact strength test in accordance with JIS K7211 and a tensile test in accordance with JIS K6782 at room temperature, and compared with the test results of unirradiated products similarly formed into sheets. As a result, the tensile strength (MD: longitudinal direction) was 260, 280 kg in the order of the unirradiated product and the irradiated product.
f · cm, the transverse direction (TD) is 210, 230 kgf ·
cm, tensile elongation (MD) 1130, 1240%, T
D is 1130, 1160%, tear strength (MD) is 16
0, 270 gf, the TD was 190 and 450 gf, and the impact strength test was 23.8 and 25.2 kgf · cm, respectively.

Reference Example 3 An electron beam was applied to the polycaprolactone used in Reference Example 1 at room temperature at 10, 20, 40, 10
Irradiation at 0 kGy was performed to measure changes in MI and gel fraction (%), and the following values were obtained in order. Electron beam dose (kGy): 0, 10, 20, 40, 1
00 MI (g / 10 min): 2.6, 1.0, 0.5, 0.1, 0.08 Gel fraction (%): 0, 0.1, 0.2, 0.3, 23.7

In Reference Examples 1 to 3, irradiation was examined for polycaprolactone to which biodegradable resin Bionole was added, but there was essentially no change.

A sample obtained by cutting a sheet obtained from 20 kGy-irradiated caprolactone in Reference Example 3 into a 10 cm square was immersed in hot water at 70 ° C., and the shrinkage was measured. As a result, the sheet obtained from unirradiated caprolactone was melted, but the 20 kGy irradiated sheet was not melted and contracted 60% in the MD direction and 30% in the TD direction.

(Preparation of Biodegradable Resin Composition) [Preparation Example 1] Polycaprolactone (Placcel H7, manufactured by Daicel Chemical Industries, Ltd., number average molecular weight 1.2)
10 g of 8 × 10 ⁵ ) pellets were placed in a 1.5 cm diameter glass ampule, which was connected to a vacuum line to remove air, and then sealed. This sample was completely melted in an oven at 80 ° C., inserted into a metal block adjusted to 45 ° C. in advance, and irradiated with 100 kGy at a dose rate of 10 kGy / hr by gamma rays from cobalt 60. After the irradiation, the glass ampule was opened, and a cylindrical PCL having a diameter of 1.5 cm was taken out. From this, cut out a thin plate about 5mm thick,
It was wrapped in a 200-mesh stainless steel wire gauze, immersed in an acetone solution for 24 hours, and the gel fraction (the ratio of insolubles, representing the degree of crosslinking) was found to be 70% by the following equation. Gel fraction _{(%) = (W 2 /} W 1) × 100 ( wherein, W ₁ represents the dry weight of the PCL before immersion, W ₂
Represents the dry weight of the insoluble matter after immersion. Further, in order to examine the heat resistance, PCL sliced to a thickness of 2 to 3 mm was compression-molded into a film by hot pressing at 200 ° C., and the obtained film was extremely excellent in transparency. Heat resistance is 100mm / min tensile speed
Using a high temperature tensile tester. The results are shown in Table 1. 40 parts of polycaprolactone, which has been subjected to an irradiation treatment step adjusted to have the same gel fraction as the irradiation, poly 1,
60 parts of 4-butanediol-succinate, 0.5 part of liquid paraffin and 1 part of stearamide are put into a twin-screw vented extruder (40 mm diameter) and extruded at a die temperature of 180 ° C. to obtain a resin composition. Was obtained. The MI of this resin composition is 0.1 g / 10 mi.
n.

[Preparation Example 2] The gel fraction (%) of polycaprolactone obtained through the same step as the irradiation step described in Preparation Example 1 was 82%, except that irradiation was performed with gamma rays at a dose of 150 kGy. . Further, a heat resistance test was conducted by the method described in Preparation Example 1, and the results are shown in Table 1. After the irradiation step, 40 parts of polycaprolactone, 60 parts of poly-1,4-butanediol-succinate, and liquid paraffin 0.1 part were used.
Pellets of the resin composition were obtained in the same manner as in Preparation Example 1 using 5 parts, 0.8 parts of stearic acid amide and 0.8 parts of finely divided silica (Aerosil # 200, same as above). The MI of this resin composition was 0.09 g / 10 min.

[Preparation Example 3] 40 parts of polycaprolactone and poly 1, which had undergone the same irradiation step as described in Preparation Example 2,
Resin composition as in Preparation Example 1 using 60 parts of 4-butanediol-succinate, 0.5 parts of liquid paraffin, 0.5 parts of stearamide and 0.5 parts of finely divided silica (Aerosil # 200). A product pellet was obtained. The MI of this resin composition was 0.09 g / 10 min.

[Preparation Example 4] 40 parts of polycaprolactone and poly 1, which had undergone the same irradiation step as described in Preparation Example 2,
Preparation Example 1 using 60 parts of 4-butanediol-succinate, 0.5 part of liquid paraffin, 0.5 part of stearic acid amide, 0.5 part of finely divided silica (Aerosil # 200), and 50 parts of corn starch In the same manner as in the above, pellets of the resin composition were obtained. The MI of this resin composition is 0.09
g / 10 min.

[Comparative Preparation Example 1] 40 parts of unirradiated polycaprolactone (the properties such as heat resistance are shown in Table 1 as in Preparation Example 1), 60 parts of poly 1,4-butanediol-succinate, and fluidity Pellets of the resin composition were obtained in the same manner as in Preparation Example 1 using 0.5 parts of paraffin and 0.8 parts of stearamide. The melt index of this resin composition was 3.9 g / 10 minutes.

(Examples 1-4, Comparative Example 1) Preparation Examples 1
4. A sheet was formed using the resin composition pellets prepared in Comparative Preparation Example 1, respectively, and a blister pack container and lid were formed using the sheet by air pressure molding. The blister pack of the present invention has good film moldability, moldability from a film to a blister pack, has biodegradability in a natural environment, and is excellent in strength, transparency and the like.

[0036]

[Table 1]

[0037]

The blister pack made of a biodegradable resin according to the present invention is mainly composed of a lactone resin, which is difficult to form by continuous extrusion or injection molding, vacuum or pressure molding, etc. Although a resin is used, various kinds of stable molding can be performed by a specific radiation irradiation treatment in a raw material or a manufacturing process, and a blister pack or the like made of a resin having excellent biodegradability has been successfully obtained. These have made it possible to provide environmentally friendly food containers, especially blister packs and trays, based on their biodegradability.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08L 1/00 C08L 1/00 3/00 3/00 5/00 5/00 67/02 67/02 67/04 ZAB 67 / 04 ZAB 89/00 89/00 93/00 93/00 // B29K 1:00 29:00 67:00 277: 00 311: 00 (72) Inventor Hiroshi Mitomo 1-1-5 Tenjincho, Kiryu-shi, Gunma No. Gunma University Faculty of Engineering (72) Inventor Dharmawan Dalwis 1-5-1, Tenjincho, Kiryu-shi, Gunma Gunma University Faculty of Engineering (72) Inventor Tadashi Murakami 1-323 Shinmatsudo Minami, Matsudo-shi, Chiba

Claims (8)

[Claims] A blister pack or tray made of a biodegradable resin obtained by molding a lactone resin alone or a biodegradable resin composition containing a lactone resin into a packaging container, wherein the blister pack or tray is made of the biodegradable resin. A blister pack or tray made of a degradable resin, wherein the lactone resin of the above (1) has been subjected to radiation irradiation treatment alone or together with at least one other component. 2. The blister pack or tray made of a degradable resin according to claim 1, wherein the other biodegradable resin is a synthetic and / or natural polymer. 3. The blister pack or tray made of a degradable resin according to claim 2, wherein the synthetic polymer is an aliphatic polyester, a biodegradable cellulose ester, a polypeptide, a polyvinyl alcohol, or a mixture thereof. 4. The blister pack or tray made of a degradable resin according to claim 2, wherein the natural polymer is starch, cellulose, carrageenan, chitin / chitosan, natural linear polyester resin, or a mixture thereof. 5. Photodecomposition, biodegradation accelerators, heat stabilizers, lubricants, coloring agents, flame retardants, water resistance agents, autoxidizers, ultraviolet stabilizers, crosslinking agents, antibacterial agents, antioxidants, deodorants The blister pack or tray made of a degradable resin according to any one of claims 1 to 4, further comprising an agent, a nucleating agent, an antiblocking agent, or a mixture thereof. 6. The tensile elastic modulus (JIS K7127) of a sheet constituting a blister pack or a tray is 100 to 100.
800 N / mm ² or impact strength (JIS K7
The blister pack or tray made of a degradable resin according to any one of claims 1 to 5, wherein (211) is 10 to 50 kg · cm. 7. The resin constituting the blister pack or tray has a glass transition point of −60 to 20 ° C.
6. The blister pack or tray made of a degradable resin according to any one of 6. 8. The blister pack or tray made of a degradable resin according to claim 1, wherein the lactone resin is polyε-caprolactone.