JPH11279392A - Degradable tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a tape with excellent degradability, moldability and mechanical properties. SOLUTION: The degradable tape 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-containing resin composition (e) comprising the lactone-containing resin (c) and a resin additive (d), and the lactone resin (a) which constitutes the degradable tape is one having been subjected to the irradiation treatment solely or together with at least one of the other constituents. The tape is used for packaging, adhesive tapes, labeling and the like.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a lactone-containing resin comprising a specific radiation-treated lactone resin alone or a lactone resin and another biodegradable resin.
Or a decomposable tape formed by molding a lactone-containing resin composition comprising the lactone-containing resin and a resin additive,
It has excellent decomposability, moldability and mechanical properties.

[0002]

2. Description of the Related Art Conventionally, tapes used for packing tapes, bands, adhesive tape base materials, labels, and tapes for various other industrial materials include natural materials such as paper, polyolefin resins, and polyvinyl chloride resins. , Polyester resin,
Synthetic resins such as polyamide resins are mainly used. However, natural materials such as paper are vulnerable to moisture, which limits the range of use. When discarded, the tape produced from a synthetic resin increases the amount of garbage, and when buried, it remains semi-permanently underground, and when discarded, poses a problem of damaging the landscape. Until now, there has been no degradable tape that decomposes in a 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 formed into various shapes such as films and put to practical use. However, in addition to the physical properties required as a degradable tape, the biochemical degradability required after disposal, and the like, there is still an excellent resin composition that is balanced in the moldability required during the production of films and the like. Not proposed. JP-A-8-188706 discloses that a biodegradable resin, polycaprolactone (hereinafter sometimes abbreviated as PCL) is 80 to 100% by weight and a biodegradable linear polyester resin produced by living organisms. Lubricant 0.3-0.8 with respect to 100 parts by weight of a mixture with 20 to 0% by weight.
Although a biodegradable plastic film bag obtained by molding a composition comprising parts by weight is disclosed, there is a problem in mechanical strength at the time of film forming, and it is difficult to mass-produce the film. Not only that, even if the film is put into a composting device together with garbage, the biochemical decomposition of the film takes 100 days, so the decomposition rate is not sufficiently fast.

[0004] Also, JP-A-8-11206 discloses that
Proposals have been made to use downward dies for inflation film formation of biodegradable resin, but there is no solution to the problem based on the characteristics of the biodegradable resin itself, only by lowering the extrusion direction. Therefore, it has not been a fundamental solution to the problem in inflation film formation of a biodegradable resin. Japanese Patent Application Laid-Open No. 8-150658 discloses heat sealability, mechanical strength, and the like using a composition comprising a biodegradable aliphatic polyester and a saponified ethylene-vinyl acetate copolymer, starch and a plasticizer. Although a method of forming an inflation film having excellent moisture resistance and the like is disclosed, since a biodegradable ethylene-vinyl acetate copolymer saponified compound is present, some of the biodegradable properties are sacrificed. This is not a disclosure of a solution to the above problem.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a resin, a resin composition, and a resin composition having excellent decomposability, moldability, and mechanical properties using a lactone resin. To provide a decomposable tape obtained by the above method.

[0006]

Means for Solving the Problems The present inventors have made intensive studies to achieve the above object, and have found that lactone resins and aliphatic polyester resins represented by polycaprolactone which have been subjected to radiation treatment under specific conditions. The present invention has been found that by adding a lubricant, a plasticizer, a heat stabilizer, etc., a decomposable tape with a good balance in terms of film formability, film physical properties, biodegradability after disposal, etc. can be obtained. Was completed.

That is, a first aspect of the present invention is to provide a lactone-containing resin (c) composed of a lactone resin (a) alone or a lactone resin (a) and another biodegradable resin (b), or the lactone-containing resin (c). ) And a resin additive (d), which is a decomposable tape formed by molding a lactone-containing resin composition (e), wherein the component lactone resin of the decomposable tape is used alone or at least one other component. And a decomposable tape characterized by being subjected to a radiation irradiation treatment. In the second aspect of the present invention, a lactone resin (a)
Is ε-caprolactone, 4-methylcaprolactone,
3,5,5-trimethylcaprolactone, 3,3,5-
Various methylated caprolactone such as trimethylcaprolactone, β-propiolactone, γ-butyrolactone,
The degradable tape according to the first aspect of the present invention, which is a homopolymer of δ-valerolactone or enantholactone, a copolymer of two or more of these monomers, or a mixture of these homopolymers or copolymers. A third aspect of the present invention provides the degradable tape according to any one of the first to second aspects of the present invention, wherein the gel fraction of the lactone resin in the lactone-containing resin is 0.05 to 90%. A fourth aspect of the present invention provides the degradable tape 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. The fifth of the present invention
Provides the degradable tape according to the fourth aspect of the present invention, wherein the synthetic polymer comprises an aliphatic polyester, a biodegradable cellulose ester, a polypeptide, a polyvinyl alcohol, or a mixture thereof. A sixth aspect of the present invention is the fourth aspect of the present invention, wherein the natural polymer comprises starch, cellulose, paper, pulp, cotton, hemp, carrageenan, chitin / chitosan, natural linear polyester resin, or a mixture thereof. The present invention provides a decomposable tape as described in 1. The seventh aspect of the present invention is that the resin additive is a plasticizer, a heat stabilizer, a lubricant, an antioxidant, an ultraviolet stabilizer, an antistatic agent, a flame retardant, a dropping agent, an antibacterial agent, a deodorant, a filler, a coloring agent. Or the first to the present invention which is a mixture thereof
6. A degradable tape according to any one of 6. An eighth aspect of the present invention provides the degradable tape according to any one of the first to seventh aspects of the present invention, which is uniaxially or biaxially stretched. A ninth aspect of the present invention is the first aspect of the present invention, which has irregularities on one or both surfaces.
The present invention provides a degradable tape according to any one of claims 1 to 8. A tenth aspect of the present invention provides the degradable tape according to any one of the first to ninth aspects of the present invention, which has an adhesive layer, a release agent layer, and / or a heat seal layer on one or both surfaces. An eleventh aspect of the present invention is the first to tenth aspects of the present invention reinforced with biodegradable fibers.
The present invention provides a degradable tape according to any one of the above. According to a twelfth aspect of the present invention, there is provided the degradable tape according to any one of the first to eleventh aspects of the present invention, which is used for packing, adhesive tape, and display.

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The lactone resin used in the present invention is a homopolymer of a lactone monomer, a lactone copolymer comprising two or more lactone monomers, or a copolymer of a lactone monomer and a monomer other than the lactone monomer. , And mixtures thereof. Examples of the lactone monomer include ε-caprolactone; 4-methylcaprolactone, 2,2,4-trimethylcaprolactone,
Various methylated caprolactones such as 3,5-trimethylcaprolactone; β-propiolactone; γ-butyrolactone; δ-valerolactone; and enantholactone. 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

In the present invention, another biodegradable resin may be used in combination with polylactone. The other biodegradable resin is not particularly limited as long as it can be molded into a degradable tape in combination with the lactone resin.
Alternatively, a natural polymer is used. As the synthetic polymer, aliphatic polyester, biodegradable cellulose ester, polypeptide, polyvinyl alcohol, ethylene-
Examples include a vinyl acetate copolymer or a mixture thereof. Examples of the natural polymer include starch, cellulose, paper, pulp, cotton, wool, silk, chitin / chitosan, natural linear polyester resin, or a mixture thereof.

An aliphatic polyester resin as a synthetic polymer is a polyester resin other than a lactone resin,
It is an aliphatic polyester resin obtained by a condensation polymerization system.
Examples of the aliphatic polyester resin, polylactic acid, polymers of hydroxycarboxylic acids such as polylactic acid copolymer,
Copolymers: polyesters and copolyesters of low molecular weight aliphatic dicarboxylic acids and low molecular weight aliphatic diols. Examples of the polylactic acid include ECOPLA (manufactured by Cargill), Lacty (manufactured by Shimadzu Corporation), and the like. Examples of the polyester of a low-molecular aliphatic dicarboxylic acid and a low-molecular aliphatic diol include a linear or branched aliphatic diol having 1 to 10 carbon atoms and a polyester composed of a linear or branched aliphatic dicarboxylic acid having 1 to 10 carbon atoms. Is preferred. A diol content of 20% by weight to 70% by weight and an aliphatic dicarboxylic acid content of 30% by weight to 80% by weight are used. As the aliphatic polyester resin, G
Number average molecular weight is 2 in terms of standard polystyrene by PC
0000 or more and 200,000 or less, preferably 40,
More than 000 can be used. Examples of commercially available polyesters from aliphatic diols / aliphatic dicarboxylic acids include biodegradable polyester resins such as polyethylene succinate and polybutylene succinate, for example, Bionole (manufactured by Showa Polymer Co., Ltd.). it can.
An aliphatic polyester resin having a high molecular weight by forming a urethane bond by reacting an aliphatic diisocyanate such as hexamethylene diisocyanate with a low molecular weight polyester from an aliphatic diol / aliphatic dicarboxylic acid can also be used.

When polycaprolactone and polylactic acid are used, the weight ratio is from 99/1 to 1/99, preferably from 90/10 to 60/40. When using a polyester from polycaprolactone and a diol / aliphatic dicarboxylic acid, the weight ratio is 80/20 to 20/80.
It is blended in the range. When three kinds of polylactic acid, polyester from diol / aliphatic carboxylic acid, and biodegradable polymer of polycaprolactone are mixed and used, the polymerization ratio of polyester from diol / aliphatic carboxylic acid to polycaprolactone is 30/70 to 70. / 30,
Polymerization ratio of polylactic acid and polycaprolactone is 20/80
Formulated to be ~ 80/20.

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 propionate; Hybrid esters such as cellulose acetate butyrate, cellulose acetate phthalate and cellulose nitrate 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 as the synthetic polymer include polyamino acids and polyamide esters.

Examples of the starch include raw starch, processed starch, and mixtures thereof. 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 amount of the starch added is not particularly limited, but in order to effectively achieve the purpose of addition, 10% by weight of the lactone resin or 100 parts by weight of the total amount of the lactone resin and the aliphatic polyester resin. The amount is preferably from 80 to 80 parts by weight, and particularly preferably from 25 to 50 parts by weight.

As the lubricant used in the present invention, those generally used 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. The compounding amount is 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight of a lubricant based on 100 parts by weight of the lactone resin or the total of the lactone resin and other biodegradable resin. If the amount is less than 0.05 part by weight, the effect is not sufficient, and if the amount is more than 5 parts by weight, the material is not wound around a roll, and the physical properties are deteriorated. As a commercially available product, RIQUESTER EW-100 (manufactured by RIKEN Vitamin Co., Ltd.)
And Hoechst wax OP (manufactured by Hoechst).

Examples of the plasticizer used in the present invention include aliphatic dibasic acid esters, phthalic acid esters, hydroxy polycarboxylic acid esters, polyester plasticizers, fatty acid esters, epoxy plasticizers, and mixtures thereof. For example, di-2-ethylhexyl phthalate (D
OP), phthalic acid esters such as dibutyl phthalate (DBP) and diisodecyl phthalate (DIDP), adipic acid esters such as di-2-ethylhexyl adipate (DOA), diisodecyl adipate (DIDA), and azelaic acid-diamine Polyester plasticizers such as azelaic acid esters such as -2-ethylhexyl (DOZ), hydroxy polyvalent carboxylic acid esters such as tri-2-ethylhexyl acetylcitrate and tributyl acetylcitrate, and polypropylene glycol adipate; Is used in one kind or in a mixture of two or more kinds. Preferably, di-2-ethylhexyl azelate (DO)
Z). The addition amount of these plasticizers is preferably in the range of 3 to 30 parts by weight based on 100 parts by weight of the lactone resin or the total of the lactone resin and another biodegradable resin. Further, it is preferably 5 to 15 parts by weight. 3
If it is less than parts by weight, elongation at break and impact strength will be low,
On the other hand, if it exceeds 30 parts by weight, the breaking strength and the impact strength may be undesirably 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 amount of the lactone resin, or a total of 100 parts by weight of the lactone resin and the other biodegradable resin, in the range of 0.5 to 10 parts by weight, preferably,
It is in the range of 0.5 to 5 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.

If necessary, the lactone resin, the lactone resin composition or the composition to which the various additives have been added may be used as a photodecomposition or biodegradation accelerator, a lactone resin and a fat as components of the resin composition. Resin components other than the aromatic polyester resin (eg, ethylene / vinyl acetate copolymer (EVA) and other polyolefins, hydrogenated styrene butadiene rubber, polyurethane, polyamide, polyhydroxybutyrate, etc.), and natural polymers other than the above-mentioned starch (For example, polysaccharide-based polymer, cellulose-based polymer, protein-based polymer, etc.), fine powder particles having a diameter of 50 μm or less and manufactured from paper, heat stabilizer, filler, talc, calcium carbonate, etc. Agents, lubricants, coloring agents, flame retardants, water resistance agents, autoxidants, UV stabilizers, crosslinkers, antibacterial agents, herbicides, antioxidants, It can be added to the deodorant and the like.
Urea, alkaline earths, alkali metal hydroxides and mixtures thereof can also be added as starch modifiers. Fillers such as talc and calcium carbonate are mixed with a total of 100 parts by weight of a lactone resin such as polycaprolactone and an aliphatic polyester such as polybutylene succinate and a filler such as talc, 10 to 50 parts by weight. You. The predetermined irradiation treatment may be performed before or after the addition.

Examples of the ethylene / vinyl acetate copolymer include those having an ethylene content of 10 to 70% by weight and a vinyl acetate content of 30 to 90% by weight. Preferably, the ethylene content is 20 to 40% by weight. It has a vinyl acetate content of 60 to 80% by weight. When the vinyl acetate content is less than 30% by weight, the elongation at break decreases, and when the vinyl acetate content exceeds 90% by weight, the impact strength (Izod impact value) decreases. The weight average molecular weight is preferably about 50,000 to 500,000, and if it is less than 50,000, the breaking strength and the yield strength are reduced, and the breaking elongation is also reduced. If it exceeds 500,000, the breaking strength decreases. EVA is added in an amount of 5 to 70 parts by weight, preferably 10 to 30 parts by weight, based on 100 parts by weight of the total of the lactone resin or the lactone resin and the other biodegradable resin. E
If the VA is less than 5 parts by weight, sufficient elongation at break and impact strength cannot be obtained, and if the EVA exceeds 70 parts by weight, the transparency of the present composition is reduced, and the strength is greatly reduced. Commercially available E
For VA, Ebaslen 250, 310P, 450P
(Manufactured by Dainippon Ink and Chemicals, Inc.). When the present invention is applied to a decomposable tape, if EVA is added, the shrinkage at low temperature is improved (excellent low-temperature shrinkability).
preferable.

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 promoter include oxo acids (eg, 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 (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.

The lactone resin constituting the decomposable tape of the present invention has been subjected to a predetermined irradiation treatment. As the lactone homopolymer to be subjected to the radiation irradiation treatment, those which do not soften at room temperature are particularly preferable, and from this viewpoint, polycaprolactone (PCL) having a high molecular weight and a melting point of 60 ° C. or more, which is easy to obtain stable performance, is preferable. .

Hereinafter, the lactone resin according to the present invention will be described using polycaprolactone as a typical example. Polycaprolactone has a number average molecular weight of 10,000.
１，1,000,000 is preferred, but 100,000，500,000 is particularly preferred in terms of efficient crosslinking. Polycaprolactone having the above molecular weight is JIS K6
It has a relative viscosity of 1.15 to 2.80 according to the definition of 726, and particularly preferably has a relative viscosity of 1.50 to 2.80. Examples of commercially available polycaprolactone include Plaxel (manufactured by Daicel Chemical Industries, Ltd.).

The lactone resin irradiated with the radiation may be a lactone resin used alone as a film raw material, or a lactone resin and at least one other component constituting the lactone resin composition may coexist. Good. Here, the other at least one component constituting the lactone resin composition is another biodegradable resin, a lubricant, a plasticizer, a heat stabilizer, or the like.

In the present invention, the irradiation time of radiation is
Before molding, during molding, may be at any stage after molding, preferably, powdery or pellet-shaped lactone resin alone,
This is performed on the lactone resin composition. In the case of these compositions, it may be a simple mixture of each component in the form of powder or pellets, but the mixture in a properly kneaded state is powdered,
Or a pelletized product is more preferable. In addition, a mode in which irradiation is performed at a low dose first and then a high dose is performed at a later stage is also included. For example, the gel fraction is 0.01 to 10 in the pellet stage.
%, Preferably 0.05 to 1.0%, and 1 to 90%, preferably 10 to 9% during or after molding.
Irradiation can be performed so as to be 0%. By irradiating so that the gel fraction becomes 0.01 to 10%, preferably 0.05 to 1.0%, crosslinking occurs, the melting point becomes higher, tensile strength and tear strength are improved, and gold The releasability from the mold and the roll adhesion are reduced, and the 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, 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 decomposable tape of the present invention is obtained by molding the lactone-containing resin (c) or the lactone-containing resin composition (e) into a tape or a film using a T-die extruder or the like. It is obtained by cutting the obtained film into a tape shape, forming a fiber or a fiber bundle into a tape shape by weaving or knitting them, or arranging and adhering fibers into a tape shape by fusing or the like. . The tape may be laminated with another biodegradable resin material or may be reinforced with fiber. The degradable tape may be uniaxially or biaxially stretched, may be provided with irregularities on one or both surfaces to give an effect such as anti-slip, etc., an adhesive layer, a release agent layer on one or both surfaces. And / or a heat seal layer may be provided. The tape of the present invention is used for packing, band, adhesive tape, heat seal tape, gap tape, separator, cover tape, packaging material tear tape, display, side tape of diapers and sanitary goods, etc. Is done.

[0028]

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 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 normal 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

Incidentally, 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, 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 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. 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, which had been subjected to an irradiation treatment step adjusted to have the same gel fraction as the irradiation, and liquid paraffin 0.1 part.
5 parts and 1 part of stearic acid amide were put into a twin screw type vented extruder (40 mm diameter), and extruded at a die temperature of 180 ° C. to obtain a resin composition pellet. 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, poly-1, which had undergone the same steps as the irradiation step 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 (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 1 Using the pellets of the resin compositions prepared in Preparation Examples 1 to 4 and Comparative Preparation Example 1, tapes were formed at a longitudinal stretching ratio of 5 times using a T-die extruder.
The tapes obtained in Preparation Examples 1 to 4 were balanced in terms of moldability, strength, and decomposability.

Example 2 Polycaprolactone (PCLH7) irradiated at normal temperature with an electron beam irradiation amount of 20 kGy
(Daicel Chemical Industries, Ltd.) 30 parts and poly 1,4-
Butanediol-succinate (Bionole # 10
01 (manufactured by Showa Polymer Co., Ltd.)) and 30 parts of talc were added to 70 parts of a lactone-containing resin, and the mixture was placed in a twin-screw vented extruder (40 mm diameter). To obtain a pellet of the lactone-containing resin composition, and then a tape was produced using the pellet. As a result, conventional polypropylene packaging and
A tape equal to or better than the packaging tape was obtained. In addition, the tape was subjected to a biodegradability test. As a result, about 75% of the tape was decomposed by activated sludge in 28 days. Biodegradability test method: The tape obtained above was pulverized and crushed in an urban sewage sludge environment according to JIS K6950.
It was subjected to an 8-day biodegradability test.

[0041]

According to the present invention, the heat resistance and biodegradability are improved, and the decomposable tape is well balanced in terms of moldability, physical properties during use, and chemical decomposability after disposal. An adhesive tape was obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08G 63/16 C08G 63/16 C08L 1/00 C08L 1/00 3/00 3/00 5/08 5/08 29/04 29 / 04 D 67/00 67/00 77/00 77/00 101/12 ZAB 101/12 ZAB C09J 7/02 C09J 7/02 Z // C08J 7/00 CFD C08J 7/00 CFD 305 305 (72) Invention Person Hiroshi Mitomo 1-5-1, Tenjincho, Kiryu-shi, Gunma Gunma University Faculty of Engineering (72) Inventor Dharmawan Dalwis 1-15-1 Tenjincho, Kiryu-shi, Gunma Gunma University Faculty of Engineering (72) Inventor Tadashi Murakami 1-323 Shin-Matsudo South, Matsudo City, Chiba Prefecture

Claims (12)

[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 tape obtained by molding the lactone-containing resin composition (e) comprising d), wherein the lactone resin constituting the decomposable tape is subjected to radiation irradiation alone or together with at least one other component. A degradable tape characterized by the fact that: 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. 2. The decomposable tape according to claim 1, which is a homopolymer of γ-butyrolactone, δ-valerolactone, enantholactone, a copolymer of two or more of these monomers, or a mixture of these homopolymers or copolymers. 3. The decomposable tape according to claim 1, wherein the gel fraction of the lactone resin in the lactone-containing resin is 0.05 to 90%. 4. The degradable tape according to claim 1, wherein the other biodegradable resin is a synthetic and / or natural polymer. 5. The degradable tape 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,
Pulp, cotton, hemp, carrageenan, chitin / chitosan,
The degradable tape according to claim 4, comprising a natural linear polyester-based resin or a mixture thereof. 7. The resin additive may be a plasticizer, a heat stabilizer, a lubricant,
The decomposable tape 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. . 8. The decomposable tape according to claim 1, which is uniaxially or biaxially stretched. 9. The decomposable tape according to claim 1, which has irregularities on one or both surfaces. 10. The decomposable tape according to claim 1, having an adhesive layer, a release agent layer and / or a heat seal layer on one or both surfaces. 11. The method according to claim 1, which is reinforced with biodegradable fibers.
11. The decomposable tape according to any one of 10). 12. The decomposable tape according to claim 1, which is used for packing, adhesive tape, and display.