JPH11279390A - Degradable trash bag - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain degradable trash bags having well-balanced properties such as moldability of its film and the bag made of the film, material properties at use of the bag, biodegradability after disposed and the like by molding a radiation-treated lactone resin or a biodegradable resin composition containing the lactone resin. SOLUTION: A preferable biodegradable resin composition contains 0.2-5 parts by weight of a fatty acid amide against 100 parts by weight of the total of a lactone resin and a synthesized aliphatic polyester resin. The lactone resin which is the component of biodegradable trash bags, is radiation-treated singularly or with at least one other component. The weight ratio of the lactone resin to the synthesized aliphatic polyester resin is preferably 5/95-70/30. Optionally, 0.1-3 parts by weight of a liquid lubricant, 0.1-3 parts by weight of a fine powder silica, 10-80 parts by weight of a starch or the like is added to 100 parts by weight of the total of the lactone resin and the synthesized aliphatic polyester resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to a biodegradable lactone resin which is environmentally friendly even if discarded.
Because of its relatively low temperature of ℃, there is a limit to its application to packaging materials such as films.Specific radiation treatment is applied to improve the heat resistance, tear strength, etc. by introducing a network structure. It is intended to expand applications. More specifically, at least the lactone resin has been subjected to a specific radiation treatment, and the lactone resin alone or a composition containing at least the lactone resin, particularly a lactone resin, a biodegradable resin composed of a synthetic aliphatic polyester resin and a fatty acid amide The present invention relates to a collapsible garbage bag obtained by forming a film of the composition. Further, the present invention relates to a disintegrable garbage bag obtained by molding a biodegradable resin composition obtained by further adding a liquid lubricant or starch to the composition.
Further, the present invention relates to a disposable garbage bag which is a garbage bag for compost or a garbage bag made of a draining net obtained by molding.

[0002]

2. Description of the Related Art Various types of waste, especially food waste, are often stored in a disposal bag and buried in the ground as they are. Chemical or biochemical (hereinafter sometimes abbreviated as "biochemical") decomposition has been required, and various bags for disposal using biodegradable resins have been proposed. Here, biodegradable resin, when used as a bag material, has almost the same physical properties as general-purpose plastics, but after disposal, in the natural environment such as on soil, in activated sludge, in soil, in water, in compost, etc. Refers to macromolecules that are rapidly biochemically decomposed and assimilated by microorganisms such as bacteria and molds or natural conditions such as temperature, humidity, and light, and eventually turn into carbon dioxide and water depending on the type.

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 resin-polyolefin-based resins are known, and these resins or resin compositions are practically formed into various shapes such as films (bags). However, in addition to the physical properties required as the bag material, the biochemical degradability required after disposal, etc., the moldability required in the production of films (bags) etc. is balanced. An excellent resin composition that has been taken has not yet been proposed.

For example, Japanese Patent Application Laid-Open No. 8-150658 proposes specific molding conditions for molding using a resin composition comprising a starch-EVOH-polycaprolactone resin. According to the gazette, a lubricant is used in an amount of 0.3 to 0.1% by weight based on 100 parts by weight of a mixture of 80 to 100% by weight of polycaprolactone and 20 to 0% by weight of a biodegradable linear polyester resin produced by living organisms.
There is disclosed a garbage storage bag made of a biodegradable plastic, which is molded with a composition containing 8 parts by weight.
When the molding conditions described in JP-A-8-150658 are adopted, there is a problem that EVOH does not have sufficient biodegradability. Furthermore, the garbage storage bag disclosed in JP-A-8-188706 has a problem in mechanical strength at the time of molding, and it is difficult to mass-produce the film.

On the other hand, radiation widely used industrially for modification of polymer materials by crosslinking or the like includes γ-rays from cobalt 60 and electron beams from accelerators. In particular, for applications requiring high strength and high melt viscosity, a high degree of crosslinking is required. In that case, since radiation crosslinking occurs mainly in the amorphous region of the polymer material, a large dose of, for example, 200 kGy is required for the irradiation treatment at around room temperature. Conversely, treatment near the melting point tends to generate a large number of voids and reduce strength.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to balance all aspects such as moldability of a film and a bag obtained therefrom, physical properties of the bag at the time of use, and biochemical degradability after disposal. It is an object of the present invention to provide a collapsible garbage bag, and more specifically, to provide a garbage-filling bag or a garbage-filling net bag for garbage filling with biochemical decomposition (disintegration).

[0007]

Means for Solving the Problems The present inventor has conducted intensive studies to achieve the above object, and as a result, performed radiation treatment.
A lactone resin represented by polycaprolactone, or a biodegradable composition containing a lactone resin, especially a resin composition using a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide, has good moldability and physical properties of a film molded product ( For example, improvement in tear strength, particularly in the transverse direction (TD)), biodegradability after disposal, etc.
In particular, they have found that they are suitable as compost garbage bags or drainer net bags, and have completed the present invention.

That is, the first aspect of the present invention comprises a lactone resin alone or a biodegradable resin composition containing at least a lactone resin, or the second aspect of the present invention comprises a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide,
Total 10 of lactone resin and synthetic aliphatic polyester resin
A disintegrable garbage bag formed by molding a biodegradable resin composition having a fatty acid amide ratio of 0.2 to 5 parts by weight to 0 part by weight, wherein the lactone resin as a component of the disintegrable garbage bag is used alone. Or a collapsible garbage bag that has been subjected to a radiation irradiation treatment together with at least one other component. Third, the weight ratio of lactone resin / synthetic aliphatic polyester resin is 5/95.
The present invention relates to the collapsible garbage bag according to the second aspect of the present invention, which is ７０70/30. A fourth aspect of the present invention is the disintegration according to the second or third aspect, further comprising 0.1 to 3 parts by weight of a liquid lubricant based on 100 parts by weight of the total of the lactone resin and the synthetic aliphatic polyester resin. It is related to sex garbage bags. A fifth aspect of the present invention is the disintegratable garbage bag according to any one of the second to fourth aspects of the present invention, further comprising 10 to 80 parts by weight of starch based on 100 parts by weight of the total of the lactone resin and the synthetic aliphatic polyester resin. It is about. In the sixth aspect of the present invention, fine powder silica is further added to 0.1 part by weight based on 100 parts by weight of the total of the lactone resin and the synthetic aliphatic polyester resin.
The present invention relates to the collapsible garbage bag according to any one of the second to fifth aspects of the present invention, which contains 1 to 3 parts by weight. A seventh aspect of the present invention is the first to the first aspects of the present invention, wherein the collapsible garbage bag is a compost garbage bag.
6. The collapsible garbage bag according to any one of 6. The eighth aspect of the present invention relates to the collapsible garbage bag according to any one of the first to seventh aspects of the present invention, wherein the collapsible garbage bag is a drainage net garbage bag. A ninth aspect of the present invention relates to the collapsible garbage bag according to the eighth aspect, wherein the collapsible garbage bag is a garbage bag made of a draining net for compost. A tenth aspect of the present invention relates to the collapsible trash bag according to any one of the first to ninth aspects, wherein the lactone resin is poly-ε-caprolactone.

[0009]

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 50 ° C. or more, which can easily obtain stable performance.
Caprolactone (sometimes referred to as PCL or polycaprolactone) is preferred. Hereinafter, the lactone resin according to the present invention will be described using polycaprolactone as a typical example. The polycaprolactone includes, besides a homopolymer of ε-caprolactone, a copolymer using a comonomer such as valerolactone, glycolide or lactide, and has a number average molecular weight of 10,000 to 300,
000 is preferred, but 40,00 for practical bridging.
Those having 0 to 150,000 are particularly preferred.

[0010] The biodegradable resin composition used in the present invention contains at least a lactone resin. The other biodegradable resin constituting the composition is not particularly limited as long as it can be mixed with a lactone resin and formed into a film as a composition, and various known resins are used. Preferred examples of such a biodegradable resin include aliphatic polyesters (to be further exemplified later), biodegradable cellulose esters, polypeptides, and starch (to be further exemplified later). These can be used alone or in combination of two or more. As the biodegradable cellulose ester, cellulose acetate, cellulose butyrate,
Organic acid esters such as cellulose propionate; inorganic acid esters such as cellulose nitrate, cellulose sulfate, and cellulose phosphate; and hybrid esters such as cellulose acetate propionate, cellulose acetate butyrate, cellulose acetate phthalate, and cellulose nitrate acetate. . 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 and polyamide esters. Preferably, such a biodegradable resin composition is obtained by adding a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide. Hereinafter, the present invention will be described using this composition as an example, but the same applies to a case where a lactone resin is used alone or a composition of lactone and another biodegradable resin.

As a preferred example of the present invention, in a collapsible garbage bag formed by molding a biodegradable resin composition comprising a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide, at least the lactone resin constituting the collapsible garbage bag Is the one that has been irradiated. Therefore, as the resin composition used in the present invention, the lactone resin alone is irradiated with radiation, and in addition to the resin composition obtained by adding a synthetic aliphatic polyester resin and a fatty acid amide thereto,
A resin composition obtained by mixing a lactone resin and a synthetic aliphatic polyester resin or a fatty acid amide and performing radiation irradiation treatment and then mixing the remaining components, a lactone resin, a synthetic aliphatic polyester resin, and a fatty acid amide are mixed and irradiated. A resin composition obtained by the treatment is also included. Further, as a composition to be subjected to radiation irradiation treatment by mixing these three components, in addition to a mode of irradiating a composition as a molding raw material (eg, pellets or a strand after kneading for pellet production), a composition being molded may be used. The irradiation mode is also included. In order to improve the biodegradability of the molded article, it is preferable to mold using a resin composition containing a lactone resin obtained by irradiation treatment, for example, pellets.

The above-mentioned biodegradable resin composition used in the present invention may further contain a liquid lubricant, finely divided silica and / or starch, and the irradiation treatment may be performed after the addition. . Similarly, the biodegradable resin composition of the present invention may contain a plasticizer, a photodegradation accelerator, and a biodegradation accelerator.

The synthetic aliphatic polyester resin used in the present invention is a polyester resin other than a 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). The polyester resin includes a resin whose molecular weight is improved by a diisocyanate compound. As the aliphatic polyester resin, the number average molecular weight in terms of standard polystyrene by GPC is usually from 20,000 to 200,000,
Preferably, those having 40,000 or more can be used. Their melting points are usually 90-110 ° C.

The one-component fatty acid amide of the biodegradable resin composition according to the present invention includes lauric amide, palmitic amide, high-purity palmitic amide, stearic amide, purified stearic amide, high-purity stearic amide, Saturated fatty acid monoamides such as behenic acid amide, high-purity behenic acid amide, hydroxystearic acid amide and oleic acid amide; methylene bisstearic acid amide;
Ethylene biscapric acid amide, ethylene bislauric acid amide, ethylene bisstearic acid amide, ethylenebisisostearic acid amide, ethylenebishydroxystearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, hexamethylenebisbehenic acid amide Saturated fatty acid bisamides such as hexamethylene bishydroxystearic acid amide, N, N'-distearyl adipamide, N, N'-distearyl sebacic acid amide; oleic acid amide, purified oleic acid amide, purified erucic acid amide , Unsaturated fatty acid monoamides such as ricinoleamide; ethylenebisoleamide, hexamethylenebisoleamide,
Unsaturated fatty acid bisamides such as N, N'-dioleyl adipamide, N, N'-dioleyl sebacamide; N-stearyl stearamide, N-oleyl oleamide, N-stearyl oleamide;
Substituted amides such as N-oleyl stearamide, N-stearyl erucamide, N-oleyl palmitamide; methylol stearamide; methylol amides such as methylol behenamide; N, N-distearyl isophthalate Fatty acid amides such as aromatic bisamides such as acid amide and meta-xylylene bisstearic acid amide. These are solid lubricants at room temperature.

Among the above fatty acid amides, ethylene bisstearic acid, which is highly safe and is registered with the FDA (US Food and Drug Administration), from the viewpoint of preventing environmental pollution due to the disintegratable garbage bag according to the present invention. Amides, stearamides, oleamides, and erucamides are preferred.

When an appropriate fatty acid amide is selected from the above fatty acid amides according to the present invention, it is of course necessary to select a fatty acid amide having a melting point lower than the melting point of various aliphatic polyester resins to be blended. . For example,
In consideration of the melting point of the synthetic aliphatic polyester resin, a fatty acid amide of 160 ° C. or lower is selected as the fatty acid amide.

According to the radiation irradiation treatment of the present invention, the powdery or pelletized lactone resin alone, a composition having at least a lactone resin, particularly a composition comprising a lactone resin and a synthetic aliphatic polyester resin, It is performed on a composition comprising a lactone resin and a fatty acid amide, or a composition comprising a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide. In addition, in the case of these compositions, a simple mixture of each component in the form of powder or pellets may be used, but a mixture obtained by appropriately kneading the mixture is more preferably powdered or pelletized. Further, when irradiation is performed during film formation, the lactone resin is irradiated once while being heated and melted at a temperature equal to or higher than the melting point, whereby the crystals of the lactone resin are collapsed, and the lactone resin is irradiated while it is still in an amorphous state even when cooled. And a high degree of cross-linking is obtained, which is efficient. Of course, the irradiation treatment may be performed after the molded lactone resin is crystallized.

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, the γ-rays or electron beam irradiation treatment using an electron accelerator can be used to introduce a crosslinked structure of a polymer material. Is the most convenient.

The radiation irradiation treatment according to the present invention is excellent in heat resistance, strength and the like by irradiating the lactone resin with radiation. In particular, when the film is stretched at 60 ° C. or more and cooled, transparency and heat shrinkage are obtained. And a film molded product for a collapsible garbage bag or a net-like garbage bag is obtained. In addition,
In the case of the treatment with the above-mentioned various compositions composed of other components instead of the treatment with the lactone resin alone, the same effect can be obtained because the lactone resin component causes crosslinking.

The crosslinking reaction, which is the effect of radiation treatment of the lactone resin in the present invention, occurs even with a small irradiation dose, and is effective even at room temperature of about 15 kGy, and the degree of crosslinking increases as the dose increases. The radiation dose rate is not particularly limited, but when a high degree of crosslinking is required, a higher dose rate is preferable because the production efficiency is improved. The atmosphere at the time of the radiation treatment is not particularly limited, but it is advantageous that the lower the oxygen concentration, the smaller the irradiation dose.

The preferred mixing ratio of each component constituting the biodegradable resin composition according to the present invention will be described. First, the compounding ratio of the lactone resin to the aliphatic polyester resin is preferably 30 to 95% by weight of the former (70 to 5% by weight) (total 100% by weight of both), but in this case, the upper limit of the former is 60%. It is particularly preferred that the content is not more than 40% by weight, and the range of 60 to 90% by weight of the latter is more preferable than 40 to 10% by weight of the former. In this case, if the lactone resin exceeds 70% by weight, the mechanical properties at high temperature of a molded product such as a film tend to decrease, and if it is less than 5% by weight, disintegration based on biochemical decomposition may decrease. This tendency is 40 ~
The same can be said for a case outside the range of 10% by weight. On the other hand, if the amount of the aliphatic polyester resin exceeds 95% by weight, the biodegradability tends to be slow, and
When the amount is less than the weight percentage, for example, when processed into a film, heat resistance may be reduced. The same can be said for the case where this tendency is out of the range of 60 to 90% by weight.

The compounding ratio of the fatty acid amide is preferably from 0.2 to 5 parts by weight, more preferably from 0.3 to 1.5 parts by weight, based on 100 parts by weight of the total of the lactone resin and the aliphatic polyester resin. preferable. If the fatty acid amide is less than 0.2 parts by weight, the anti-blocking effect of the film molded product is slightly lowered, while if it exceeds 5 parts by weight, the slipperiness of the film tends to be unnecessarily high, and the printability, adhesiveness, etc. Begins to show a downward trend.

When the material for forming a film is irradiated with radiation, the melt fluidity of the biodegradable resin composition according to the present invention comprising the above-mentioned irradiated lactone resin, aliphatic polyester resin and fatty acid amide is as follows. The resin composition is not particularly limited as long as the resin composition can be used for film forming. For film forming for disintegrating garbage bags or net garbage bags, a melt flow index (MI) is used.
(Measured at 190 ° C with a load of 2160 g) is 0.01
-10 g / 10 min, preferably 0.3 to 10 g / 10 min.
3 g / 10 min is suitable. The degree of crosslinking of the lactone resin is 10% or less, preferably 0.1 to
It is in the range of 1%. When the irradiation treatment is performed during or after the molding, unlike the case where the irradiation treatment is performed on the molding raw material, the melt fluidity has little or no problem. Conditions can be set to perform a high degree of crosslinking. In this case, the gel fraction of the lactone resin is usually in the range of 1 to 90%.

The biodegradable resin composition according to the present invention may further contain a liquid lubricant, finely divided silica, starch and the like, if necessary. The purpose of use of the liquid lubricant is that the lactone resin or the aliphatic polyester resin as the resin component constituting the resin composition is usually supplied in the form of pellets or beads as described above, and the fine powder having an extremely small bulk specific gravity as described below. This is because, in order to uniformly mix silica and the like, it is preferable to keep the surfaces of the pellets and beads as wet as possible. The amount of the liquid lubricant having such a purpose of use is preferably 0.1 to 3 parts by weight, more preferably 0.2 to 0.1 part by weight, based on 100 parts by weight of the total amount of the lactone resin and the aliphatic polyester resin. It is added in the range of 7 parts by weight. If the added amount exceeds 3 parts by weight, a large amount of the liquid lubricant adheres to the inner surface of the mixing tumbler, and it may be difficult to produce a stable and sticky material. If the added amount is less than 0.1 part by weight, the effect as a wetting agent is sufficient. May not be able to demonstrate. This tendency is also observed outside the more preferred range of 0.2 to 0.7 parts by weight.

Therefore, the liquid lubricant as a wetting agent preferably has a melting point of 70 ° C. or less, and more preferably a liquid lubricant at ordinary temperature. For example, in addition to liquid paraffin, paraffin wax, stearyl alcohol, stearic acid, etc., stearic esters such as butyl stearate, monoglyceride stearate, pentaerythritol tetrastearate, stearyl stearate and the like can be mentioned.

The most preferred liquid paraffin in the above liquid lubricants has an oral acute toxicity (rat) LD50 of 5 g / k.
g, it is very safe, is recognized as a food additive under the Food Sanitation Act, and is a very convenient material in terms of preventing environmental pollution when garbage bags are discarded. As described above, a liquid lubricant was selected as the lubricant, but if a solid lubricant is used, the entire system including the resin composition needs to have a melting point of the solid lubricant or higher, and a low temperature of the melting point or lower. It is difficult to use. Liquid paraffin, which is liquid at room temperature, is a preferred lubricant in this regard.

The purpose of using the finely divided silica is to prevent blocking of the disintegratable garbage bag or its material film according to the present invention. The fine powdered silica used may be silica produced by a wet method, silica produced by high-temperature hydrolysis of silicon tetrachloride in an oxyhydrogen flame, and the like, particularly those having a particle size of 50 nm or less. Is preferred. As the addition method, a method in which the mixture is heated and kneaded in a mixture of the resin composition or the lactone resin and the aliphatic polyester resin according to the present invention is most preferable, and the secondary aggregated particles are unraveled by the action of a considerably high shear force, It has the effect of preventing blocking of film and bags of products. In addition, the addition amount of the fine powder silica is most preferably in the range of 0.1 to 3 parts by weight based on 100 parts by weight of the mixture of the lactone resin and the aliphatic polyester resin in view of the above effects.

Various starches can be added to the resin composition according to the present invention. The addition of the starch improves biodegradability and economic efficiency. The amount of the starch added is not particularly limited, but in order to effectively achieve the purpose of addition, 10 to 80 parts by weight based on 100 parts by weight of the total amount of the lactone resin and the aliphatic polyester resin. Preferred, but 25-50
The range of parts by weight is particularly preferred.

The starches that can be used for the above purpose include:
Raw starch, processed starch and mixtures thereof are included. Examples of the raw starch include corn starch, horse bell chopsticks starch, sweet potato starch, wheat starch, cassava starch, sago starch, tapioca starch, rice starch, legume starch, kuzu starch, bracken starch, lotus starch, and heishi starch. Examples of the 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-modified starch (acid-treated starch, hypochlorite). Acid-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 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 , A reaction product of starch and 2,3-epoxypropyltrimethylammonium chloride, etc .; Examples of the crosslinked starch include formaldehyde crosslinked starch, epichlorohydrin crosslinked starch, phosphoric acid crosslinked starch, and acrolein crosslinked starch.

The photodegradable or biodegradable accelerator, a lactone resin and an aliphatic resin as components of the resin composition may be added to the biodegradable resin composition or the composition further containing the various additives, if necessary. Resin components other than the polyester resin (for example, polyamide ester resin synthesized from ε-caprolactone and ε-caprolactam, polyamino acid resin,
Ethylene copolymers and other polyolefins, hydrogenated styrene butadiene rubber, polyurethane, polyamide, polyhydroxybutyrate, etc., and natural polymers other than the above-mentioned starch (for example, polysaccharide polymers, cellulose polymers, protein systems) Polymer, etc.), fine powder particles manufactured from paper having a diameter of 50 microns or less, plasticizers, heat stabilizers, extenders, fillers such as calcium carbonate, lubricants, coloring agents, flame retardants, water resistance agents, automatic Resin additives such as oxidizing agents, ultraviolet stabilizers, crosslinking agents, antibacterial agents, herbicides, antioxidants, deodorants, nucleating agents, and antistatic agents can be added. Urea, alkaline earths, alkali metal hydroxides and mixtures thereof can also be added as starch modifiers.

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.

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.

As a method for obtaining a blended composition obtained by adding the various additives to the biodegradable resin composition, various methods conventionally used can be applied, and are not particularly limited. For example, to describe an example of a method for producing the above composition, first, a lactone resin and an aliphatic polyester resin and a liquid lubricant are placed in a tumbler, and
Then, the fatty acid amide is added, and the fine powder silica and starch are added thereto, and the mixture is further stirred and mixed for 20 to 30 minutes. After that, a 14 or single screw extruder or the like is used.
Melt kneading is performed at about 0 to 210 ° C. to obtain powder or pellets of the resin composition containing various additives.

The powdery or pelletized additive-containing resin composition obtained as described above is subjected to an inflation method,
-Formed by conventional various forming methods such as a die method and processed into a film. For example, a method of forming a film by an inflation method is described below. First, it is supplied to an extruder equipped with an annular die, melt-kneaded at a temperature of 180 ° C., and extruded into a tube from an annular die slit. For example, the extrusion diameter of the extruder at this time is about 40 to 65 mm, the length / diameter ratio (L / D) is 26 to 32,
The diameter of the annular die can be 50 to 150 mm, and the gap of the die slit is preferably in the range of 0.5 to 1.5 mm. The extruded tube-shaped film expands to a predetermined diameter with a blow ratio (tube diameter / die diameter) of 2 or more by the pressure of gas introduced from a gas blowing pipe inserted through the die, and then It is folded by a nip roll and taken off at a constant speed. The resin composition or the various additive-containing resin compositions obtained through the radiation irradiation treatment step according to the present invention, under an environmental temperature close to room temperature, regardless of the temperature of the resin extruded from the annular die, stably Film production is possible, but when the outside air temperature is extremely high, such as in summer, when cold air of 20 ° C. or less is introduced from the gas blow-in tube, a more completely film free of blocking can be obtained. The same applies to the case where the film being formed is irradiated with radiation.

In the case where the film is a single flat sheet such as a T-die film, the film cut into an appropriate size is folded and, for example, a garbage bag is obtained by bonding the side surfaces, and the inflation method is used. In the case of a cylindrical shape such as a film, a garbage bag can be obtained by bonding the bottom. The method of bonding may be heat fusion or a method using an adhesive.However, it is preferable that the adhesive also has biodegradability. The fusion method is preferred. The thickness of the film varies depending on the application, but as a household garbage bag
m, 50 to 50% for large garbage bags with large contents
Those having a thickness of 200 μm are preferably used.

In the case of garbage in which it is preferable to remove the contained water, a garbage bag made of a draining net is used as a collapsible garbage bag. The easiest way to obtain the drainage net garbage bag mentioned here is to form a large number of drainage holes in the wall surface of the collapsible garbage bag having ordinary watertightness. There is no particular problem as long as the hole is provided at a position where the draining function can be exerted. The hole may be provided on both sides or one side of the wall surface, or on the upper, lower, or entire surface. There is no particular limitation on the shape of the holes and the mutual positional relationship of the holes as long as the strength and function as a drainable garbage bag are within the intended range,
The shape may be, for example, a circular hole, and the mutual positional relationship may be regularly arranged vertically, may be obliquely shifted, or may be irregularly provided. The diameter of the hole depends on the size of the minimum waste to be filled,
Usually, 0.1 to 5 mm is preferable, and 1 to 3 mm is more preferable. The number of holes is preferably 10 per 10 cm square.
２０００2000, more preferably 100-1500. In addition, a nonwoven fabric made of a split cloth obtained from a molded film, a woven fabric using a stretched tape, a nonwoven fabric, and the like can also be used. The garbage bag made of the drainer net thus obtained can be used for draining by laying it inside a garbage container placed in a corner of a kitchen sink or the like.

The collapsible garbage bag according to the present invention is effective because it can be subjected to a biodegradation treatment together with garbage. After draining, put it in a compost container as it is, the garbage bag may be biodegraded together with garbage to be composted, or collected by a garbage truck, then discarded on the ground and discarded in the soil to biodegrade the whole May be.

[0038]

EXAMPLES The present invention will now be described specifically 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. Melt index is 190
It is a value showing the flow characteristics at a load of 2160 g at ° C.

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, electron beams were irradiated at 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 with an electron beam at a dose of 15 kGy at room temperature. 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 and JIS at room temperature.
A tensile test was performed according to K6782, and the results were compared with the test results of an unirradiated product similarly formed into a sheet. As a result, the tensile strength (MD: longitudinal direction) was 260, 280 kgf · cm, and the transverse direction (TD) in the order of the unirradiated product and the irradiated product.
Are 210 and 230 kgf · cm, and the tensile elongation (MD) is 1
130, 1240%, TD is 1130, 1160%,
The tear strength (MD) is 160, 270 gf, and the TD is 19
0, 450 gf, impact strength test 23.8, 25.2
kgf · cm respectively.

(Preparation of Biodegradable Resin Composition) [Preparation Example 1] Polycaprolactone (Placcel H7, trade name, manufactured by Daicel Chemical Industries, Ltd., number average molecular weight 7 × 1)
0 ⁴⁾ the pellets 10g were placed in a glass ampoule of 1.5cm diameter were熔封Following removal of air by connecting it to a vacuum line. After the sample was completely melted in an oven at 80 ° C., it was inserted into a metal block that had been adjusted to 45 ° C. in advance, and a dose rate of 10 k was applied with γ-rays from cobalt 60.
Irradiation was performed at 100 kGy at Gy / hr. After the irradiation, the glass ampule was opened, and a cylindrical PCL having a diameter of 1.5 cm was taken out. From this, a thin plate with a thickness of about 5 mm is cut out and 200
Wrap in mesh stainless steel wire mesh and
It was immersed for a period of time, and the gel fraction (the ratio of insolubles, which represents the degree of crosslinking) was determined by the following equation, and was 70%. 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 1 at a pulling speed of 100 mm / min.
It was determined using a 20 ° C. high temperature tensile tester. 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 a gel fraction similar to the irradiation. 2
The mixture was placed in a shaft screw type vented extruder (40 mm diameter) and extruded at a die temperature of 180 ° C. to obtain pellets of the resin composition. The melt index of this resin composition was 0.1 g / 10 minutes.

[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 fine powdered silica ("Aerosil # 200" manufactured by Nippon Aerosil Co., Ltd.).
The melt index of this resin composition was 0.09 g / 1.
It was 0 minutes.

[Preparation Example 3] 40 parts of polycaprolactone, poly1, which had undergone the same irradiation step as described in Preparation Example 2,
Pellets of the 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 Aerosil # 200 (same as above). I got The melt index of this resin composition was 0.09 g / 10 minutes.

[Preparation Example 4] 40 parts of polycaprolactone, poly 1, which had undergone the same irradiation step as described in Preparation Example 2,
4-butanediol-succinic ester 60 parts, liquid paraffin 0.5 part, stearic acid amide 0.5 part, Aerosil # 200 (same as above) 0.5 part, corn starch 5
Using 0 parts, pellets of the resin composition were obtained in the same manner as in Preparation Example 1. The melt index of this resin composition is 0.09
g / 10 minutes.

COMPARATIVE PREPARATION EXAMPLE 1 Unirradiated polycaprolactone (40 parts), poly-1,4-butanediol-succinate (60 parts), liquid paraffin (0.5 parts), stearic acid amide (0.8 parts), fine powdered silica (Japan Pellets of the resin composition were obtained in the same manner as in Preparation Example 1 using 0.8 parts of "Aerosil # 200" manufactured by Aerosil Co., Ltd. The melt index of this resin composition was 3.9 g / 10 minutes.

(Examples 1-4, Comparative Example 1) Preparation Examples 1
4. Using the resin composition pellets prepared in Comparative Preparation Example 1, a film was produced by the inflation method under the following molding conditions, and the width was 450 m by heat sealing.
m, a vertically long garbage bag having a length of 500 mm was produced. (Molding conditions) Extruder: 40 mm diameter extruder Screw: L / D = 28, screw die for MDPE (medium density polyethylene): lip diameter 150 mm, die gap 1 mm Extrusion temperature: 170 ° C. at cylinder tip Die temperature: 170 ° C. Resin temperature (T1): 160 ° C. Screw rotation speed: 15 rpm Discharge amount: 15 kg / hr Blow ratio: 2.5 Garbage bags obtained from films using the resin compositions of Preparation Examples 1 to 4 above were each used in Example 1. 4, and a garbage bag obtained from a film using the resin composition of Comparative Preparation Example 1 was used in Comparative Example 1. Specifically, food waste generated in a kitchen at home is put into these garbage bags, and put into a composting device while the bags are still in the bag. Processed. As a result, the garbage bags according to the present invention (Examples 1 to 4) and the garbage bag of Comparative Example 1 were both biodegraded and collapsed.

Comparative Example 2 A garbage bag was prepared in the same manner as in Example 1 using a cellulose film having a thickness of 30 μm as a film, filled with garbage, and observed for biodegradability. Although the garbage bag of Comparative Example 2 was torn and curled, the film itself of the bag remained almost intact without biodegradation.

Example 5 A hole having a diameter of 1 mm was formed in the lower half of both the front and back wall surfaces of the garbage bag obtained in Example 1 vertically and horizontally.
The interval was 0 mm. By placing this garbage bag inside a triangular prism-shaped plastic storage container provided at the corner of the sink, it can be used as a draining net garbage bag,
When treated in a composting device at about 80 ° C. for 8 hours in a state where the water content was as low as possible, the garbage bag according to the present invention was biodegraded and collapsed.

[0049]

[Table 1]

[0050]

According to the present invention, a disintegrable garbage bag that can be easily decomposed chemically and biochemically in a short time on soil, in soil, in a composting device, or in other natural environments. A garbage bag made of a draining net can be provided.

 ──────────────────────────────────────────────────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 disintegrable garbage bag obtained by molding a lactone resin alone or a biodegradable resin composition containing at least a lactone resin, wherein the lactone resin as a component of the disintegrable garbage bag is used alone or in another form. A collapsible garbage bag that has been subjected to a radiation irradiation treatment together with at least one component. 2. A biodegradable composition comprising a lactone resin, a synthetic aliphatic polyester resin and a fatty acid amide, wherein the ratio of the fatty acid amide to the total of 100 parts by weight of the lactone resin and the synthetic aliphatic polyester resin is 0.2 to 5 parts by weight. A collapsible garbage bag obtained by molding a resin composition, wherein the lactone resin as a component of the collapsible garbage bag has been subjected to radiation irradiation treatment alone or together with at least one other component. Disintegrable garbage bags. 3. The weight ratio of lactone resin / synthetic aliphatic polyester resin is from 5/95 to 70/30.
The collapsible garbage bag according to 1. 4. The disintegratable garbage bag according to claim 2, further comprising 0.1 to 3 parts by weight of a liquid lubricant based on 100 parts by weight of the total of the lactone resin and the synthetic aliphatic polyester resin. 5. The disintegratable garbage bag according to claim 2, further comprising 0.1 to 3 parts by weight of fine silica powder based on 100 parts by weight of the total of the lactone resin and the synthetic aliphatic polyester resin. . 6. Starch is further added to 10 parts by weight of a total of 100 parts by weight of a lactone resin and a synthetic aliphatic polyester resin.
The disintegrable garbage bag according to any one of claims 2 to 5, comprising 80 parts by weight. 7. The collapsible garbage bag according to claim 1, wherein the collapsible garbage bag is a compost garbage bag. 8. The collapsible garbage bag according to claim 1, wherein the collapsible garbage bag is a drainage net garbage bag. 9. The collapsible garbage bag according to claim 8, wherein the collapsible garbage bag is a garbage bag made of a draining net for compost. 10. The collapsible trash bag according to claim 1, wherein the lactone resin is poly-ε-caprolactone.