JP2003212269A - Biodegradable shrink sheet material and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a biodegradable shrink sheet material which has a high thermal shrinkage capability, and transparency and heat sealing property that are well balanced with the thermal shrinkage capability. <P>SOLUTION: A compound mainly containing a mixture of (A) 95 to 80 wt.% of polylactic acid polymer and (B) 5 to 20 wt.% of biodegradable polyester resin is subjected to processes of inflation forming and forced cooling to form the sheet material having a shrinkage rate of MD 40% or more and TD 30% or more. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention is suitable for use as a biodegradable shrink sheet material having a high heat shrinkability and a good balance between transparency and heat sealability, and especially for packaging materials and label materials. Biodegradable shrink sheet material.

[0002]

2. Description of the Related Art Shrink sheets and films are well known for their main applications such as product accumulation, packaging, and bundling. They are excellent in heat shrinkability, transparency, heat sealability, etc. There is a strong demand for resin materials. Among the required characteristics, the heat shrinkability is such that during shrink wrapping, each product is melt-fused with a heat sealer and passed through a shrink tunnel that is subjected to hot air or superheated steam treatment to allow the products to be collected, packaged, and bound. Necessary for shrinkage and close contact. Transparency is important because if it is high, it is possible to easily confirm visually by a packaged object such as a packaged product, and it is generally indicated by light transmittance. The heat-sealing property is a property that allows shrink sheets and films to be pasted or bonded together by applying heat or pressure, and if excellent, it can easily produce various sheet or film processed products and packaging materials. It is important because it is possible.

Conventionally, most of plastic films having such properties, especially packaging materials, are discarded immediately after use, so that the treatment thereof is a problem. In other words, general-purpose plastic remains stable without being decomposed and remains undegraded, adversely affecting the environment and ecosystems, causing garbage problems and fauna and flora such as rivers, oceans and mountains such as seafood and algae. , Causing various problems in the habitation of wild birds. Vinyl chloride type, which is often used for packaging and labels,
Olefin type, styrene type, styrene-butadiene type,
Shrink sheets and films made of polyethylene terephthalate resin are no exception.

In addition, vinyl chloride-based resins are incinerated due to the problem that due to the composition of chlorine gas and harmful polychlorine-substituted organic substances represented by dioxins generated by high-temperature incinerator treatment of garbage containing the resin, etc. No, I can't do it, polyolefins such as polyethylene and polypropylene, polystyrene,
General-purpose plastics such as styrene-butadiene-based resins and polyethylene terephthalate-based resins have high calorific value when incinerated, and although the amount of carbon dioxide generated due to the polymer structure is very large, they are not suitable for landfill treatment. Due to the decrease and various limitations of the treatment itself, most of the waste treatment after use is incineration, and there is a problem in environmental protection such as air pollution accompanying the incineration treatment.

[0005] Therefore, in order to cope with such a problem and to perform incineration treatment, a degradable polymer has attracted attention as a plastic material which does not contain chlorine, etc. and has a small calorific value and a small amount of carbon dioxide generation at the time of incineration. Among them, polylactic acid, biodegradable polyester, etc. have a calorific value and carbon dioxide generation amount at the time of incineration as little as half of polyethylene, and decomposition in natural environment such as hydrolysis in soil or water progresses, and Various studies have been carried out because it is decomposed by the action of enzymes and enzymes.

[0006]

[Problems to be Solved by the Invention] However, polylactic acid is
It has excellent biodegradability, and when it is made into a sheet or film, it is highly transparent and heat-shrinkable, but it is weak and brittle because it is hard and poor in flexibility and adhesive strength is insufficient. However, although the biodegradable polyester has sufficient adhesive strength, it has a problem that it lacks transparency, is difficult to stretch, and has insufficient heat shrinkability. Therefore, it is an object of the present invention to provide a biodegradable shrink sheet material having a high heat shrinkability and a good balance with transparency and heat sealability.

[0007]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a polylactic acid-based polymer and a specific polyester have a mixed composition. It was found that a biodegradable shrink sheet material having a specific shrinkage rate, which is a sheet material, is suitable for it, and the present invention has been completed based on this finding.

That is, the present invention provides the following biodegradable shrink sheet material and a method for producing the same. (1) A sheet-like product obtained by inflation molding and forced cooling of a composition mainly containing a mixture of (A) a polylactic acid-based polymer (95 to 80 mass%) and (B) a biodegradable polyester-based resin (5 to 20 mass%). There is MD4
A biodegradable shrink sheet material, characterized in that it is 0% or more and TD is 30% or more. (2) The polylactic acid-based polymer is poly-L-lactic acid, poly-D-
The biodegradable shrink sheet material according to (1) above, which is at least one selected from lactic acid and a copolymer of L-lactic acid and D-lactic acid. (3) The above-mentioned (1) or (2), wherein the biodegradable polyester resin is at least one aliphatic polyester selected from polycondensates of aliphatic dicarboxylic acids and aliphatic diols and derivatives thereof. The biodegradable shrink sheet material described. (4) The biodegradable shrink sheet material according to the above (1), (2) or (3), wherein the biodegradable polyester resin is a biodegradable aromatic-aliphatic mixed polyester having elastomeric properties. (5) The biodegradable shrink sheet material according to any one of (1) to (4) above, which further comprises an antistatic agent. (6) The biodegradable shrink sheet material according to the above (5), wherein the antistatic agent is an alkyl sulfonate-based anionic surfactant. (7) The biodegradable shrink sheet material according to any one of (1) to (6), wherein the composition further contains an inflation molding aid. (8) The biodegradable shrink sheet material according to (7) above, wherein the inflation molding aid is at least one silicon-based inorganic additive selected from silica, silicic acid and silicate. (9) The biodegradable shrink sheet material according to any of (1) to (8) above, wherein the composition further contains an antiblocking agent. (10) The biodegradable shrink sheet material according to the above (9), wherein the antiblocking agent is at least one lubricant selected from amides, fatty acids, metallic soaps and fatty acid esters. (11) A composition mainly containing a mixture of 95 to 80% by mass of a polylactic acid polymer and 5 to 20% by mass of a biodegradable polyester resin, a molding temperature of 150 to 210 ° C. and a blow ratio of 2.5 to 4. A method for producing a biodegradable shrink sheet material having a shrinkage ratio of MD 40% or more and TD 30% or more, which comprises performing inflation molding at 0 and a molding speed of 5 to 18 m / min and then forcibly cooling. (12) The production method according to (11) above, wherein the composition further contains an antistatic agent. (13) The production method according to (12) above, wherein the antistatic agent is an alkyl sulfonate-based anionic surfactant. (14) The method according to (11), (12) or (13) above, wherein the composition further contains an inflation molding aid. (15) The production method according to (14) above, wherein the inflation molding aid is at least one silicon-based inorganic additive selected from silica, silicic acid and silicates. (16) The method according to any one of (11) to (15) above, wherein the composition further contains an antiblocking agent. (17) The method according to (16) above, wherein the antiblocking agent is at least one lubricant selected from amides, fatty acids, metallic soaps and fatty acid esters. In the present invention, the sheet material is a sheet or film,
The shrinkage is the value when the sheet-like material is immersed in a glycerin bath at 130 ° C for 30 seconds to shrink, and MD is the longitudinal direction.
TD means the width direction, respectively, and the silica and silicate in the inflation molding aid include not only itself but also its hydrate or hydrate. Inflation molding may also be referred to as blow sheet molding.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Inflation molding or blow sheet molding in the present invention is preferably inflation film molding (this may be referred to as blow film molding). In the present invention, the composition used for inflation molding or blow sheet molding (hereinafter referred to as molding composition) is a polylactic acid polymer as the component (A) and a biodegradable polyester resin as the component (B). The mixture mainly contains 85% by mass or more, and preferably 90% by mass or more of the total amount of the resin components in the molding composition. The molding composition or the resin component in the molding composition also includes those composed only of a mixture of the component (A) and the component (B). Further, as the resin component in the molding composition, other biodegradable resins or general-purpose resins may be used in addition to the components (A) and (B) described above. The polylactic acid-based polymer used as the component (A) in this mixture is a homopolymer of D-lactic acid or L-lactic acid, a copolymer thereof, or a mixture thereof.
Examples thereof include poly L-lactic acid which is lactic acid, poly D-lactic acid whose structural unit is D-lactic acid, and poly DL-lactic acid which is a copolymer of L-lactic acid and D-lactic acid. As poly DL-lactic acid,
It is preferable that the structural unit of L-lactic acid or D-lactic acid accounts for 90% or more because the crystallinity can be maintained to such an extent that the shrinkage ability is not significantly impaired.

The polylactic acid polymer can be produced by a known method such as a polycondensation method or a ring-opening polymerization method. In the polycondensation method, for example, D-lactic acid, L-lactic acid or a mixture thereof is directly dehydrated and polycondensed to obtain polylactic acid having an arbitrary composition. Further, in the ring-opening polymerization method, for example, lactide, which is a cyclic dimer of lactic acid, is subjected to ring-opening polymerization in the presence of a predetermined catalyst while optionally using a polymerization modifier, etc. Lactic acid is obtained. The lactide includes L-lactide, which is a dimer of L-lactic acid, D-lactide, which is a dimer of D-lactic acid, and DL, which is a dimer of D-lactic acid and L-lactic acid.
-A lactide, and a desired polymer having an arbitrary composition and crystallinity can be obtained by mixing and polymerizing these if necessary.

The biodegradable polyester resin used as the component (B) in the above mixture is a biodegradable polyester, for example, an aliphatic polyester which is a polycondensation product of an aliphatic dicarboxylic acid and an aliphatic diol, or a cyclic polyester. Aliphatic polyester, which is a ring-opening polymer of lactones,
Other synthetic aliphatic polyesters, biosynthetic aliphatic polyesters, biodegradable aromatic-aliphatic mixed polyesters having elastomeric properties, mixtures thereof and the like can be mentioned.

When the aliphatic polyester is a polycondensation product of an aliphatic dicarboxylic acid and an aliphatic diol, examples of the aliphatic dicarboxylic acid include succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedicarboxylic acid and the like. Further, examples of the aliphatic diol include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol and the like. Examples of such aliphatic polyesters include a polybutylene succinate derivative obtained by extending the chain length of a polyester resin obtained by using 1,4-butanediol and succinic acid with polyisocyanate to give a high molecular weight compound, and 1,4 There is a derivative of a polybutylene succinate / adipate copolymer obtained by extending the chain length of a polyester resin obtained from butanediol, succinic acid, and adipic acid with polyisocyanate to give a high molecular weight.

Examples of the above cyclic lactones are ε-caprolactone, δ-valerolactone, β-methyl-δ-
Valerolactone and the like. Examples of the other synthetic aliphatic polyesters described above include copolymers of cyclic acid anhydrides and oxiranes, for example, copolymers of succinic anhydride and ethylene oxide or propion oxide.

An example of the above-mentioned biosynthetic aliphatic polyester is an aliphatic polyester biosynthesized by acetyl coenzyme A (acetyl CoA) in the fungus body such as Alcaligenes eutrophus. This is mainly poly-β-hydroxybutyric acid, but a copolymer having a valeric acid unit as a structural unit is industrially advantageous in order to improve practical properties as a plastic. The proportion of valeric acid units is generally 0-40%. Such a copolymer may be a copolymer of a long chain hydroxyalkanoate.

The biodegradable aromatic-aliphatic mixed polyester having elastomeric properties, which is used as the component (B) in the above mixture, is an aliphatic polyester which is a polycondensation product of an aliphatic dicarboxylic acid and an aliphatic diol. Part of the aliphatic dicarboxylic acid is an aromatic dicarboxylic acid,
For example, those substituted with terephthalic acid, phthalic acid, etc.,
For example, it is at least one selected from polycondensates of aliphatic dicarboxylic acids, aromatic dicarboxylic acids and aliphatic diols and their derivatives.

The biodegradable polyester resin can be made higher in molecular weight by lengthening the chain length during the polymerization by using a small amount of a chain extender such as a diisocyanate compound, an epoxy compound or an acid anhydride. .

The polylactic acid-based polymer and the biodegradable polyester-based resin described above have a suitable mass average molecular weight of 60,000 to 300,000, preferably 90,000 to 200,000 for the polylactic acid-based polymer. When it is less than this range, practical physical properties are hardly expressed, and when it exceeds this range, the melt viscosity is too high and the moldability is poor, and the biodegradable polyester resin is 6
In the range of 10,000 to 300,000, preferably 90,000 to 200,000,
When it is less than this range, practical physical properties are hardly expressed, and when it exceeds this range, the melt viscosity is too high and the moldability is poor.

In the mixture of the above-mentioned components (A) and (B) mainly constituting the molding composition, the ratio of both components is 95-80% by mass of the polylactic acid-based polymer of the component (A), preferably In the range of 93 to 80% by mass, the biodegradable polyester resin as the component (B) is selected in the range of 5 to 20% by mass, preferably 7 to 20% by mass. If the amount of the component (A) deviates from this range, the strength decreases and the brittleness increases and the flexibility decreases, and if the amount of the component (B) is too large, the transparency decreases and the stretching The characteristics deteriorate and the heat shrinkability becomes poor.

In the general-purpose resin molded product, an antistatic agent may be applied to the surface or kneaded in order to impart antistatic property. The application of the antistatic agent that imparts antistatic properties to the sheet material of the present invention is easier in the kneading method than in the coating method in terms of process, since molding is performed by an inflation machine. Further, the kneading method is preferable to the coating method in order to maintain the antistatic property. As the antistatic agent, an alkyl sulfonate-based anionic surfactant is preferable, but a nonionic surfactant, for example, fatty acid ester of polyhydric alcohol, sorbitan fatty acid ester, alkylene oxide adduct of higher alcohol or polyhydric alcohol, Among them, the ethylene oxide adduct and the like may be used. The content of the antistatic agent is preferably selected in the range of 0.1 to 10 parts by mass per 100 parts by mass of the sheet material of the present invention. The antistatic effect is exerted as an improvement in efficiency when shrink-processing the sheet-like product of the present invention or when used as a film packaging material, and prevention of dust adhesion during product packaging. Further, the antistatic effect is, for example, that the surface resistivity is 10 ¹⁴ Ω or more when the antistatic agent is not contained, but becomes 5 × 10 ¹³ Ω or less when the antistatic agent is contained. Can be confirmed.

The molding composition preferably further contains an inflation molding aid. By using this additive, it was difficult to obtain a practical shrink-sheet material having a sufficient shrinkage rate by inflation molding or blow-sheet molding, and the desired material was easily obtained. Like As the inflation molding aid, silica-based inorganic additives such as silica, silicic acid and silicates are preferable, but alumina, silica-
Inorganic additives such as alumina, calcium carbonate, zinc oxide, titanium oxide and mica are also used, and silica, quartz, silica stone, silica sand, amorphous silica, colloidal silica, hydrous silica, etc. Magnesium silicate,
Examples thereof include aluminum silicate, calcium silicate, hydrates and hydrates thereof (eg, talc, kaolinite, etc.), and silica is particularly preferable. These may be used alone or in combination of two or more. Inflation molding aids, especially inorganic additives such as silicon-based inorganic additives, have an average particle size of 5
nm to 30 μm, and particularly preferably 10 nm to 5 μm. If the average particle size is less than 5 nm, the particles are likely to aggregate to deteriorate workability, and if the average particle size exceeds 30 μm, fine irregularities are likely to be generated on the surface of the sheet-like material to impair the appearance and reduce transparency. . Further, the content of the inflation molding aid, especially the silicon-based inorganic additive is 0.1 to 5 parts by mass, and especially 0.1 to 5 parts by mass per 100 parts by mass of the molding composition.
It is preferable to select in the range of 3 parts by mass. Content is 0.1
If it is less than 5 parts by mass, the effect of addition is not sufficient, and if it exceeds 5 parts by mass, the transparency is lowered.

The sheet material of the present invention preferably further contains an antiblocking agent. This is preferably contained in the molding composition. Examples of antiblocking agents include lubricants such as amides, fatty acids, metallic soaps and fatty acid esters. These may be used alone or in combination of two or more. Examples of this amide include fatty acid amides such as stearic acid amide, oleic acid amide, and erucic acid amide, methylenebisstearic acid amide, ethylenebisstearic acid amide,
There are alkylene bis fatty acid amides such as ethylene bis oleic acid amide. Examples of fatty acids include stearic acid, behenic acid, 12-hydroxystearic acid and the like. Examples of metallic soaps include calcium stearate, zinc stearate, magnesium stearate and the like. Examples of fatty acid esters include stearyl stearate, butyl stearate, stearic acid monoglyceride, hydrogenated castor oil, and the like. The content of the antiblocking agent is 0.1 to 100 parts by mass of the sheet material of the present invention.
It is preferable to select 5 parts by mass, especially 0.1 to 3 parts by mass. When the anti-blocking agent is contained in the molding composition, the content thereof is 100%.
It is preferable to select in the range of 0.1 to 5 parts by mass, especially 0.1 to 3 parts by mass per mass part. If the content is less than 0.1 parts by mass, the effect of addition is not sufficient, and if it exceeds 5 parts by mass, the transparency decreases.

If necessary, the sheet material of the present invention may contain other biodegradable resins or non-biodegradable resins, lubricants, plasticizers, antifogging agents, antioxidants, and ultraviolet rays, as long as they do not impair the purpose. You may contain additives, such as an inhibitor, a filler, and a coloring agent.

The sheet material of the present invention is obtained by inflation-molding or blow-sheet molding a composition comprising such various components and then forcibly cooling it into a sheet, which has a shrinkage ratio of MD 40% or more. , TD 30% or more. The sheet material of the present invention varies depending on the purpose of use and application, but is 10 to 300 μm, and particularly 15 to 15 μm.
The thickness is preferably about 0 μm.

Next, a method for manufacturing a shrink sheet-like material according to the method of the present invention will be described. This shrink sheet material comprises a composition mainly containing a mixture of 95 to 80% by mass of polylactic acid polymer and 5 to 20% by mass of biodegradable polyester resin at a molding temperature of 150 to 210 ° C. and a blow ratio of 2. 5 to 4.0, molding speed 5 to 18 m / min, preferably molding temperature 170 to 200 ° C., blow ratio 2.8 to 3.
5. It can be produced by inflation molding or blow sheet molding at a molding speed of 7 to 15 m / min, and then forced cooling. Those mainly containing the above mixture also include those consisting only of the mixture of the component (A) and the component (B).

In such a manufacturing method, first, a polylactic acid-based polymer, a biodegradable polyester-based resin, an antistatic agent, an inflation molding aid, an antiblocking agent, and other various additives which are optionally used are mixed. A composition is prepared. Next, this composition is subjected to inflation molding or blow sheet molding to form a sheet that is heated and melted and expanded, and this is forcibly cooled and rapidly cooled.

If the molding temperature exceeds the molding conditions of the method of the present invention, for example, if the molding temperature is too high, the biodegradable plastic tends to be thermally deteriorated, and if it is too low, the moldability becomes poor, and if the blow ratio is too high. The sheet material is easily broken, uneven thickness, sink marks, wrinkles, scars, mottle, etc. are less likely to be homogenized, and if it is too low, the stretching properties deteriorate, the heat shrinkability becomes poor, and the molding speed increases. If it is too much, the sheet-like material is likely to break, and uneven thickness, sink marks, wrinkles, scars, mottles, etc. are likely to occur and it becomes difficult to homogenize, and if it is too low, the stretching properties deteriorate and the heat shrinkability becomes poor.

Forced cooling is performed because it is necessary to cool in a short time in order to improve shrinkability and transparency. For example, cooling machines may be provided in multiple stages or a water-cooling type internal cooling machine may be provided. By combining these methods, for example, a blower equipped with a spot cooler and a pinch roller equipped with a water-cooled refrigerant circulation cooling device are used. Such forced cooling improves the shrinkability of the sheet-like material because the biodegradable resin, in particular, polylactic acid is heated and melted and then naturally cooled, the cooling rate or the temperature decreasing rate is a general-purpose resin such as polyethylene. Since it is much slower than the above, it takes a long time to cool, for example, about 2 to 3 times as much as that in the case of polyethylene. With such a long cooling time, crystallization occurs in the biodegradable resin, especially in the polylactic acid part. This is partly because the biodegradable resin, especially the polylactic acid part, is amorphized by the rapid cooling, where spherulites are promoted, spherulites develop and stretching is difficult, and sufficient shrinkage is difficult to obtain.

According to the method of the present invention, during the inflation molding or the blow sheet molding, a suitable stretching is performed by adopting the molding conditions described above, and a sheet material obtained in combination with the forced cooling treatment is obtained. Good heat shrinkability is imparted. Therefore, according to the method of the present invention, until now, it was complicated because it required a work step of once producing a molded product and taking it out, and then a separate working process of further heating and stretching the molded product. It can be easily performed without requiring a stretching treatment.

[0029]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited to these examples. In addition, the measurement and evaluation of the physical properties of the sheet-shaped material sample of each example were performed as follows.

(1) Shrinkage rate The sample is cut to prepare a test piece having a length of 100 mm for both MD and TD. This test piece was immersed in a glycerin bath at 130 ° C. for 30 seconds to shrink, and then MD and TD after the shrinkage.
Was calculated, and the shrinkage rate was calculated for each of MD and TD by the following equation. Shrinkage rate (%) = {(dimension before shrinkage)-(dimension after shrinkage)} / (dimension before shrinkage) × 100

(2) Transparency (haze) The haze was determined according to JIS K7105.

(3) Heat-sealing property The heat-sealing strength was determined according to JIS Z1711.

(4) Comprehensive evaluation The above-mentioned physical properties were comprehensively evaluated according to the following criteria. ◯: Good performance as a whole. X: It does not have sufficient performance as a whole.

Example 1 90 parts by mass of Lacty 9031 (manufactured by Shimadzu Corporation, polylactic acid type polymer, mass average molecular weight 150,000), Bionole #
3001 (trade name, polybutylene succinate / adipate copolymer derivative manufactured by Showa High Polymer Co., Ltd.) 10 parts by mass, Dasper 902D (trade name, alkyl sulfonate anionic surfactant manufactured by Miyoshi Yushi Co., Ltd.) 1 part by mass 0.2 parts by mass of Silohobic 100 (trade name, manufactured by Fuji Silysia Chemical Ltd., silica powder), and Alflo E-10 (trade name, manufactured by NOF CORPORATION, amide blocking inhibitor).
2 parts by mass were mixed, and the mixture was blown with the blow ratio shown in Table 1.
Inflation molding or blow sheet molding under the molding conditions of a molding temperature of 180 ° C. and a molding speed of 10 m / min, and the obtained melt film is rapidly cooled by an air ring device installed as an in-line, and a shrink of 25 μm in thickness A film was obtained as a sample.

Examples 2 to 4 and Comparative Examples 1 to 3 As shown in Table 1, shrink films were obtained as samples in the same manner as in Example 1 except that the composition of the mixture and the molding conditions were changed. The physical properties of these samples were investigated,
The evaluation results are also shown in Table 1.

[0036]

[Table 1]

The composition components in the table are as follows. -Mixed polyester resin: ENPOL 8002 (trade name, manufactured by Korea Ile Chemical Co., Ltd., with some succinic acid units of polybutylene succinate changed to terephthalic acid units)

From Table 1, it can be seen that the shrink films of Examples 1 to 4 have high heat shrinkability, and also have good transparency and heat sealability. On the other hand, in the sample of Comparative Example 1 in which the blending composition ratio of the polylactic acid-based polymer is small, both the shrinkage rate and the transparency are greatly reduced, and the inflation molding or blow sheet molding molding conditions deviate from the specified range of the present invention. In the sample of Comparative Example 2 in which the shrinkage rate decreases, the sample of Comparative Example 3 in which the composition ratio of the predetermined biodegradable polyester resin exceeding the specified range of the present invention significantly decreases the transparency. It In addition,
In the above Examples and Comparative Examples, the transparency, heat shrinkability, and heat sealability of the samples were noted, and biodegradability was not mentioned, but due to the characteristics of the resin used in the present invention, the sheet form of the present invention was used. It is self-evident that the material has good biodegradability.

[0039]

EFFECTS OF THE INVENTION The sheet material of the present invention is biodegradable, has less heat generation when incinerated than general-purpose resins, and does not easily damage the incinerator. It also has high heat shrinkability, transparency and heat sealability. Since it has a good balance with and has an antistatic property in some cases, it contributes to the reduction of environmental load and is also useful as a shrink label material or a packaging material. Items include trays, containers, foods such as fresh food, cosmetics, pharmaceuticals, music media (CD, MD, cassette tape, etc.), video media (video, DVD, etc.), computer media (F
D, MO, CD, DVD, etc.), communication media (mobile phones, etc.), stationery, miscellaneous goods, etc., and examples of trays and containers include those made of glass, plastic, paper and the like.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 3E067 AA11 AB01 AB38 AB40 AB79                       AB81 BA10B BA18C BB14C                       CA01 CA30 EA29 FB01 FC01                 3E086 AB01 AD05 AD16 BA15 BB22                       BB51 BB67 BB87 BB90 CA01                       CA28 CA35

Claims (17)

[Claims] 1. A polylactic acid-based polymer (A) 95 to 80% by mass and a biodegradable polyester-based resin (B) 5 to 20% by mass.
A sheet-like product obtained by inflation molding and forced cooling of a composition mainly containing a mixture of
D40% or more, TD30% or more, biodegradable shrink sheet material. 2. The raw material according to claim 1, wherein the polylactic acid-based polymer is at least one selected from poly L-lactic acid, poly D-lactic acid, and a copolymer of L-lactic acid and D-lactic acid. Degradable shrink sheet material. 3. The biodegradable polyester resin is at least one aliphatic polyester selected from polycondensates of aliphatic dicarboxylic acids and aliphatic diols and derivatives thereof. Biodegradable shrink sheet material. 4. The biodegradable shrink sheet material according to claim 1, 2 or 3, wherein the biodegradable polyester resin is a biodegradable aromatic-aliphatic mixed polyester having elastomer properties. 5. The biodegradable shrink sheet material according to claim 1, which further comprises an antistatic agent. 6. The biodegradable shrink sheet material according to claim 5, wherein the antistatic agent is an alkyl sulfonate-based anionic surfactant. 7. The biodegradable shrink sheet material according to claim 1, wherein the composition further comprises an inflation molding aid. 8. The biodegradable shrink sheet material according to claim 7, wherein the inflation molding aid is at least one silicon-based inorganic additive selected from silica, silicic acid and silicate. 9. The biodegradable shrink sheet material according to claim 1, wherein the composition further contains an antiblocking agent. 10. The biodegradable shrink sheet material according to claim 9, wherein the antiblocking agent is at least one lubricant selected from amides, fatty acids, metal soaps and fatty acid esters. 11. A composition mainly containing a mixture of 95 to 80% by mass of a polylactic acid polymer and 5 to 20% by mass of a biodegradable polyester resin, at a molding temperature of 150 to 210 ° C.
A biodegradable shrink sheet having a shrinkage ratio of MD 40% or more and TD 30% or more, which is characterized by being blow-molded at a blow ratio of 2.5 to 4.0 and a molding speed of 5 to 18 m / min and then forcedly cooled. Method of manufacturing things. 12. The method according to claim 11, wherein the composition further contains an antistatic agent. 13. The method according to claim 12, wherein the antistatic agent is an alkyl sulfonate-based anionic surfactant. 14. The method according to claim 11, 12 or 13, wherein the composition further contains an inflation molding aid. 15. The inflation molding aid is silica.
The method according to claim 14, wherein the at least one silicon-based inorganic additive is selected from silicic acid and silicate. 16. The method according to claim 11, wherein the composition further contains an antiblocking agent. 17. The method according to claim 16, wherein the antiblocking agent is at least one lubricant selected from amides, fatty acids, metallic soaps and fatty acid esters.