JPH11279391A - Degradable thick-wall vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a degradable thick-wall vessel such as a bottle, a flowerpot or the like having excellent properties such as moldability, heat resistance and the like and excellent degradability. SOLUTION: The degradable thick-wall vessel is obtained by molding a lactone-containing resin (c) comprising a lactone resin (a) only or the lactone resin (a) and another degradable resin (b), or a lactone resin composition (e) comprising the lactone-containing resin (c) and a resin additive (d), the lactone resin (a) which constitutes the degradable thick-wall vessel being one having been subjected to the irradiation treatment solely or together with at least one of the other constituents. The vessel is used as a vessel for a liquid, creamy or solid food, toiletries, drugs, transportation of common materials or plant culture.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a decomposable thick container such as a bottle or a flowerpot made of a radiation-treated crosslinked lactone resin, and the degradable thick container has physical properties such as moldability and heat resistance. And excellent in decomposability.

[0002]

2. Description of the Related Art Conventionally, polyethylene terephthalate (PET) resin, polyester resin, vinyl chloride resin, polyolefin resin and the like are used for thick containers used for beverage bottles, cosmetic containers, flowerpots and the like. However, thick containers made of such a resin increase the amount of garbage when discarded, and when buried, they remain semi-permanently underground, and when discarded, pose a problem of damaging the landscape. ing. Until now, there has been no thick container that decomposes in the natural environment. Therefore, in order to solve these problems, biodegradable resins have recently attracted attention. Here, biodegradable resin, when used as a material, has almost the same physical properties as general-purpose plastics, but after disposal, in the natural environment such as on soil, in soil, in compost, in activated sludge, in water, etc. Is quickly biochemically caused by microorganisms such as bacteria and mold, or by natural conditions such as temperature, humidity, light, etc.
A macromolecule that is decomposed and assimilated. It is finely decomposed and eventually becomes carbon dioxide and water depending on the substance.

Conventionally, as a biodegradable resin, starch, EVOH (ethylene-vinyl alcohol copolymer) resin, EVOH resin, besides a specific polyester-based biodegradable resin in order to satisfy the above requirements. Blend-based resin compositions such as aliphatic polyester-based resins and aliphatic polyester-based resins-polyolefin-based resins are known, and these resins or resin compositions are practically used after being molded into various shapes such as bottles. However, in addition to the physical properties required as a thick container, the biochemical degradability required after disposal, and the excellent moldability required at the time of manufacture, an excellent resin composition is still proposed. Absent.

Japanese Patent Application Laid-Open No. 8-188706 discloses that a biodegradable resin, polycaprolactone (hereinafter sometimes abbreviated as PCL), is contained in an amount of 80 to 100% by weight and a biodegradable linear product produced by living organisms. Polyester resin 20 ~
Although a biodegradable plastic product obtained by molding a composition comprising 0% by weight is disclosed, there is a problem in mechanical strength at the time of molding and it is difficult to mass-produce the product. Even if it is put into a composting device together with garbage, it takes 100 days for biochemical decomposition, so the decomposition rate cannot be said to be sufficiently fast.

[0005] Japanese Patent Application Laid-Open No. Hei 6-276682 discloses a container using a biodegradable material such as aliphatic polyester, polyglycolic acid, polylactic acid, and polycaprolactone. However, polycaprolactone is simply described as being usable as a biodegradable resin, and is not improved at all.

Japanese Patent Application Laid-Open No. 8-58797 discloses a container formed by stretch blow molding using polylactic acid, aliphatic polyester, or the like. However, mechanical strength is insufficient for weight reduction. It is necessary to further provide a shrink film made of a biodegradable resin around the container.

[0007]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a well-balanced environmental degrader in all aspects such as moldability of a thick container, physical properties at the time of use of the container, and biochemical degradability after disposal. It is to provide a thick-walled container.

[0008]

Means for Solving the Problems As a result of intensive studies, the present inventors have found that a lactone resin typified by radiation-treated polycaprolactone, or a thick container made of a lactone resin and a synthetic aliphatic polyester resin. They have found that they are excellent in moldability, physical properties, biodegradability after disposal, and the like, and have completed the present invention.

That is, a first aspect of the present invention is to provide a lactone-containing resin (c) comprising the lactone resin (a) alone or the lactone resin (a) and another biodegradable resin (b), or the lactone-containing resin (c). ) And a lactone resin composition (e) comprising a resin additive (d), wherein the lactone resin (a) as a component of the decomposable thick container is used alone or A degradable thick container characterized by being subjected to a radiation irradiation treatment together with at least one other component. The second aspect of the present invention is that the lactone resin (a) is ε-caprolactone, 4-methylcaprolactone, 3,5,5-trimethylcaprolactone,
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 Alternatively, there is provided the degradable thick container according to the first aspect of the present invention, which is a mixture of copolymers. A third aspect of the present invention is that the lactone resin in the lactone-containing resin has a gel fraction of 0.05.
The thickness of the degradable thick container according to any one of the first to second aspects of the present invention, which is 90% to 90%. A fourth aspect of the present invention provides the degradable thick container according to any one of the first to third aspects of the present invention, wherein the other biodegradable resin is a synthetic and / or natural polymer.
A fifth aspect of the present invention is that the synthetic polymer is an aliphatic polyester,
A degradable thick container according to the fourth aspect of the present invention, comprising a biodegradable cellulose ester, polypeptide, polyvinyl alcohol, or a mixture thereof. Sixth Embodiment
Is a natural polymer, starch, cellulose, paper, pulp,
A degradable thick container according to the fourth aspect of the present invention, comprising a cotton, hemp, silk, leather, carrageenan, chitin / chitosan, natural linear polyester-based resin, or a mixture thereof. A seventh aspect of the present invention is that the resin additive is a plasticizer, a heat stabilizer, a lubricant, an antiblocking agent, a nucleating agent, a photodegradation agent, a biodegradation accelerator, an antioxidant, an ultraviolet stabilizer, an antistatic agent, a flame retardant. A decomposable thick container according to any one of the first to sixth aspects of the present invention, which is a dropping agent, an antibacterial agent, a deodorant, a filler, a colorant or a mixture thereof. An eighth aspect of the present invention is the degradability according to any one of the first to seventh aspects of the present invention, wherein the molding is extrusion molding, injection molding, blow molding, compression molding, transfer molding, thermoforming, flow molding, or lamination molding. Provide a thick container. A ninth aspect of the present invention provides the decomposable thick container according to any one of the first to eighth aspects of the present invention, which is obtained by irradiating the molded thick container with radiation. A tenth aspect of the present invention is a liquid, cream or solid food, toiletry,
The present invention provides a degradable thick container according to any one of the first to ninth aspects of the present invention, which is used for containers for pharmaceuticals, for transporting general substances, and for cultivating plants.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described specifically. The lactone resin used in the present invention has ε
-Caprolactone, 4-methylcaprolactone, 3,
Various methylated caprolactones such as 5,5-trimethylcaprolactone, 3,3,5-trimethylcaprolactone, β-propiolactone, γ-butyrolactone, δ-
Examples include valerolactone, a homopolymer of enantholactone, a copolymer of two or more of these monomers, and a mixture of these homopolymers or copolymers. In particular, those which do not soften at room temperature are preferable, and from this viewpoint, poly ε- having a high molecular weight and a melting point of 60 ° C. or more, which can easily obtain stable performance.
Caprolactone is preferred. Examples of the monomer other than the lactone monomer copolymerized with the lactone monomer include aliphatic hydroxycarboxylic acids such as lactic acid, hydroxypropionic acid, and hydroxybutyric acid; aliphatic diols and aliphatic dicarboxylic acids exemplified by the aliphatic polyester described below. Can be

Hereinafter, the lactone resin according to the present invention will be described using polycaprolactone as a typical example. The non-irradiated polycaprolactone preferably has a number average molecular weight of 10,000 to 1,000,000, and particularly preferably 100,000 to 500,000 in terms 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 aliphatic polyester, polyamide, polyamide ester, biodegradable cellulose ester, polypeptide, polyvinyl alcohol, 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. Examples of the aliphatic polyester resin include biodegradable polyester resins such as synthetic polylactic acid, polyethylene succinate, and polybutylene succinate (such resins include low molecular weight aliphatic resins represented by Bionole of Showa Polymer Co., Ltd.). Examples thereof include polyester resins synthesized from dicarboxylic acids and low molecular weight aliphatic diols), and JP-A-9-2.
No. 35360, 9-2333956, terpolymer aliphatic polyesters described in JP-A-7-17772
No. 6, lactic acid and hydroxycarboxylic acid copolymers. 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 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 polyamide esters. Examples of polyamide esters include resins synthesized from ε-caprolactone and ε-caprolactam. As an example of a synthetic polymer, for example, an aliphatic polyester resin, GP
C, the number average molecular weight is 20, in terms of standard polystyrene,
000 or more and 200,000 or less, preferably 40,00
Zero or more can be used.

As natural polymers, starch, cellulose,
Examples include paper, pulp, cotton, 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, potato chopsticks starch, sweet potato starch, wheat starch, cassava starch, sago starch, tapioca starch, rice starch, legume starch, kudzu starch,
Bracken starch, lotus starch, sis starch, and the like. Examples of the modified starch include physically modified starch (α-starch, fractionated amylose, wet heat-treated starch, etc.), enzyme-modified starch (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.). 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 is allyl ether Starch, methyl etherified starch, carboxymethyl etherified starch, hydroxyethyl etherified starch, hydroxypropyl etherified starch, etc .; Examples of the cationized starch include a reaction product of starch with 2-diethylaminoethyl chloride, and starch with 2,3- Epoxypropyltrimethylammonium chloride reactant and the like; Examples of the crosslinked starch include formaldehyde crosslinked starch, epichlorohydrin crosslinked starch, phosphoric acid crosslinked starch, and acrolein crosslinked starch.

In the present invention, the lactone-containing resin composition comprises a lactone-containing resin (c) and a resin additive (d). As a resin additive, a plasticizer, a heat stabilizer, a lubricant, an antiblocking agent, a nucleating agent, a photolytic agent, a biodegradation accelerator, an antioxidant, an ultraviolet stabilizer, an antistatic agent, a flame retardant, a dropping agent,
Examples include antimicrobial 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 preferably in the range of 3 to 30 parts by weight based on 100 parts by weight of the lactone-containing resin (c). 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,
In some cases, the breaking strength and the impact strength may be reduced.

The heat stabilizer used in the present invention includes 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 addition amount is in the range of 0.5 to 10 parts by weight based on 100 parts by weight of the lactone-containing resin (c). When a heat stabilizer is used in the above range, impact strength (Izod impact value) is improved, elongation at break, strength at break,
This has the effect of reducing the variation in impact strength.

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, polyglycerol, metal soap, modified silicone or a mixture thereof. Preferably, fatty acid esters, hydrocarbon resins and the like are used. When a lubricant is selected, it is necessary to select a lubricant having a melting point equal to or lower than the melting point of the lactone resin or other biodegradable resin. For example, in consideration of the melting point of the aliphatic polyester resin, a fatty acid amide having a melting point of 160 ° C. or less is selected as the fatty acid amide. The compounding amount is, for example, 100 parts of lactone-containing resin (c).
0.05 to 5 parts by weight of a lubricant is added to the parts by weight.
If the amount is less than 0.05 part by weight, the effect is not sufficient. 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; photoexciters 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.

Examples of the biodegradation accelerator include oxo acids (for example, oxo acids having about 2 to 6 carbon atoms such as glycolic acid, lactic acid, citric acid, tartaric acid, and malic acid), saturated dicarboxylic acids (for example, 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 (a) constituting the lactone-containing resin (c) has been subjected to a predetermined irradiation treatment. In the present invention, "the component lactone resin has been subjected to radiation irradiation alone or together with at least one other component" means that the lactone resin (a) alone and the lactone resin (a) are used alone. Irradiated before molding, during molding, or after molding in the state of a mixture with another biodegradable resin (b) and a state where at least one resin additive (d) is blended with the lactone-containing resin (c). Means that. Therefore, in the present invention, the lactone resin alone is subjected to a predetermined irradiation treatment in advance, and for example, 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 a lactone resin. The above-mentioned irradiation is performed by mixing a synthetic aliphatic polyester resin or a fatty acid amide and subjecting the same radiation irradiation treatment to a resin composition obtained by mixing the remaining components, a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide. A resin composition obtained by the treatment is also included. 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 or a mode of irradiating a molded article is used. Embodiments are also included. 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. Gel fraction 0.01-1
Irradiation so as to be 0%, preferably 0.05 to 1.0% causes cross-linking to increase the melting point, improve tensile strength and tear strength, release from the mold, and roll. Adhesion decreases and transparency increases.

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 dose is determined by 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.
For example, about 0.1 to 1% is preferable for a film. 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 crosslinking occurs mainly in the amorphous region of the polymer material, a large dose of, for example, 200 kGy is required in the irradiation treatment near room temperature, and in the treatment near the melting point, There is a tendency for a large number of voids to occur and reduce the strength. Therefore, in such a case, the lactone resin is melted at a temperature higher than the melting point (60 ° C. for polycaprolactone) and does not lead to crystallization after melting (for polycaprolactone, 50 ° C.).
(−35 ° C.). 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.

As a result of observing the effect of 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.

In the present invention, various molded articles can be obtained by molding a lactone-containing resin or a lactone-containing resin composition. After the primary molding into a preform such as a pellet, a plate, or a parison, they can be molded into a thick container in a secondary manner. Examples of the thick container include bottles, trays, and planting containers used for food, toiletry, pharmaceutical, general substance transport, and plant cultivation containers, and include liquid, cream, or solid containers. Can be accommodated. Extrusion molding, injection molding, blow molding,
Calender molding, compression molding, transfer molding, thermoforming, flow molding, lamination molding and the like are possible. When a bottle or the like is molded from a parison, vacuum molding, air pressure molding, vacuum pressure molding, or the like can be used.

As an example of a thick container, a beverage bottle will be described. Stretch blow molding is used for a beverage bottle in consideration of weight reduction and strength of the container. The preform (parison) includes a screw portion, a flange portion serving as a preform support during stretch molding, and a bottomed cylindrical portion having a preform body. In addition, as a stretch blow molding method, a cold parison method in which a preform molding step and a stretch blow molding step are divided into two steps and a hot parison method in which a preform molding step and a stretch blow molding step are performed in a series of steps are used. Molding is possible.

[0026]

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 and then cooled to 50.degree. C., and while being in an amorphous state, an electron beam was irradiated with 60 kGy and 160 kGy as radiation. 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 obtained sheet was subjected to a tear test, an impact strength test according to JIS K7211 and a tensile test according to 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 kgf in the order of the unirradiated product and the irradiated product.
・ Cm, the lateral direction (TD) is 210, 230kgf ・ c
m, tensile elongation (MD) 1130, 1240%, TD
Is 1130, 1160%, the tear strength (MD) is 160,
270 gf, the TD improved to 190 and 450 gf, and the impact strength test improved to 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 warm 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, trade name, 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,
Wrap in 200 mesh stainless steel wire mesh
It was immersed for 4 hours, and the gel fraction (the ratio of insolubles, which represents 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 heat resistance, PCL sliced to a thickness of 2 to 3 mm was compression-molded into a sheet by hot pressing at 200 ° C., but the obtained sheet was extremely excellent in transparency. For heat resistance, a tensile strength and an elongation at break were determined using a high-temperature tensile tester under the conditions of a tensile speed of 100 mm / min and 120 ° C. The results are shown in Table 1. 40 parts of polycaprolactone, 60 parts of poly-1,4-butanediol-succinate, 0.5 part of liquid paraffin, and 1 part of stearamide subjected to an irradiation treatment step adjusted to have the same gel fraction as the irradiation. Into a twin screw type vented extruder (40 mm diameter) and a die temperature of 18
The resin composition was extruded at 0 ° C. to obtain pellets. The MI of this resin composition was 0.1 g / 10 min.

[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 γ-ray 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.
5 parts, stearic acid amide 0.8 parts and fine powder silica (“Aerosil # 200” manufactured by Nippon Aerosil Co., Ltd.) 0.8
In the same manner as in Preparation Example 1 except for using the parts, pellets of the resin composition were obtained. 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, poly 1,
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 (test results of heat resistance are shown in Table 1), 60 parts of poly-1,4-butanediol-succinate, 0.5 part of liquid paraffin, 0.8 parts of stearamide,
Fine powder silica (Aerosil # 20 manufactured by Nippon Aerosil Co., Ltd.)
0 "), and pellets of the resin composition were obtained in the same manner as in Preparation Example 1 using 0.8 parts. The melt index of this resin composition was 3.9 g / 10 minutes.

EXAMPLE A thick container such as a bottle or a flowerpot was molded using the above-mentioned pellets, and was found to have good moldability, biodegradability in a natural environment, and excellent strength and transparency. ing.

[0038]

[Table 1]

[0039]

According to the present invention, a decomposable resin and a decomposable resin having excellent decomposability, moldability and mechanical properties by forming a crosslinked structure in the lactone resin by subjecting the lactone resin to a specific radiation treatment. Thick containers such as compositions, degradable molded articles, especially degradable bottles, trays and planting containers are obtained.
In particular, the melting point increases, and molding and use are possible at a higher temperature than before, and the decomposability is also improved. The molded article can be irradiated with radiation. Also, by irradiating the product,
At the same time, the thick container is sterilized.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Hiroshi Mitomo 1-5-1, Tenjin-cho, Kiryu-shi, Gunma Gunma University Faculty of Engineering (72) Inventor Dharmawan Dalwis 1-5-1, Tenjin-cho, Kiryu-shi, Gunma Gunma University Faculty of Engineering (72) Inventor Tadashi Murakami 1-323 Shinmatsudo Minami, Matsudo City, Chiba Prefecture

Claims (10)

[Claims] 1. A lactone-containing resin (c) comprising a lactone resin (a) alone or a lactone resin (a) and another biodegradable resin (b), or a lactone-containing resin (c) and a resin additive ( A decomposable thick container obtained by molding the lactone resin composition (e) comprising d), wherein the lactone resin (a) as a component of the decomposable thick container is used alone or in at least one other composition. A decomposable thick container, which has been subjected to a radiation irradiation treatment together with components. 2. The lactone resin (a) is selected from the group consisting of various methylated caprolactones such as ε-caprolactone, 4-methylcaprolactone, 3,5,5-trimethylcaprolactone, and 3,3,5-trimethylcaprolactone, and β-propiolactone. , Γ-butyrolactone, δ-valerolactone, a homopolymer of enantholactone, a copolymer of two or more of these monomers, or a mixture of these homopolymers or copolymers. container. 3. The decomposable thick container according to claim 1, wherein the lactone resin in the lactone-containing resin has a gel fraction of 0.05 to 90%. 4. The degradable thick container according to claim 1, wherein the other biodegradable resin is a synthetic and / or natural polymer. 5. The container according to claim 4, wherein the synthetic polymer comprises an aliphatic polyester, a biodegradable cellulose ester, a polypeptide, a polyvinyl alcohol, or a mixture thereof. 6. The natural polymer may be starch, cellulose, paper,
The decomposable thick container according to claim 4, comprising pulp, cotton, hemp, silk, leather, carrageenan, chitin / chitosan, natural linear polyester resin, or a mixture thereof. 7. The resin additive may be a plasticizer, a heat stabilizer, a lubricant,
Antiblocking agent, nucleating agent, photolytic agent, biodegradation accelerator,
The decomposable meat according to any one of claims 1 to 6, which is an antioxidant, an ultraviolet stabilizer, an antistatic agent, a flame retardant, a dropping agent, an antibacterial agent, a deodorant, a filler, a colorant, or a mixture thereof. Thick container. 8. The decomposable thick container according to claim 1, wherein the molding is extrusion molding, injection molding, blow molding, compression molding, transfer molding, thermoforming, flow molding, or lamination molding. 9. The decomposable thick container according to claim 1, which is obtained by irradiating the molded thick container with radiation. 10. The degradable product according to claim 1, which is used for a liquid, cream or solid food, toiletry, pharmaceutical, general substance transport, or plant cultivation container. Thick container.