JPH071583A - Antistatic heat-shrinkable polyester film - Google Patents

Abstract

PURPOSE:To provide a heat-shrinkable polyester film generating no trouble due to static electricity and good in shrink finish. CONSTITUTION:In a heat-shrinkable polyester film wherein a heat shrinkage factor at 100 deg.C is 40% or more (primary heat shrinkage factor) in a main shrink direction and 20% or less in the direction right-angled to the main shrink direction, the 40% heat shrinkage factor (secondary heat shrinkage factor) obtained when the polyester film is heated for 10sec in hot air in the main shrink direction at 100 deg.C is 12% or more and the intrinsic surface resistivity of the film is 1X10<13>OMEGA/square or less.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a heat-shrinkable polyester film which is suitable as a packaging material used for coating, binding, exterior packaging and the like. In particular, it gives a beautiful finished appearance with very few defects such as wrinkles, distortion, and whitening of shrinkage spots when it is heat-shrinked, and it has excellent antistatic properties and heat with less trouble due to static electricity. The present invention relates to a shrinkable polyester film.

[0002]

2. Description of the Related Art Heat-shrinkable films are used for various containers such as bottles (including glass and plastic bottles) and cans, and long objects (pipes, rods, wood, various rods, etc.).
It is used for coating, binding, or exterior. For example, it is used for covering a part or the whole of the cap, shoulder, and body of a bottle for the purpose of marking, protection, bundling, and improvement of commercial value. In addition, a box,
It is also used for applications in which a plurality of bottles, plates, notebooks, etc. are accumulated and packaged, and applications in which a film is brought into close contact with a film to be packaged (skin package). The above applications make use of the shrinkage and shrinkage stress of the film. As the material of the film, polyvinyl chloride, polystyrene, polyethylene, rubber hydrochloride, etc. are used. Usually, these films are formed into a tube shape, for example, after covering a bottle or accumulating pipes,
Packaging or binding is performed by heat shrinking. However, since the conventional film has poor heat resistance and cannot withstand any high temperature boil treatment or retort treatment, it cannot be sterilized at high temperature. For example, when a retort process is performed, the conventional film is damaged during the process. Further, when a conventional film, for example, a polyvinyl chloride film is printed, the adhesion to ink is poor.
Furthermore, since vinyl chloride lacks heat resistance, gels of polymers and additives are likely to be partially formed during film forming. Because of this gel-like material, pinholes are likely to occur on the printed surface.

Since the above-mentioned conventional film shrinks with time after manufacturing, the printing pitch changes due to the shrinkage, and high-precision printing cannot be performed. On the other hand, a heat-shrinkable film using a polyester excellent in heat resistance, weather resistance and solvent resistance has been proposed. This polyester heat-shrinkable film has been problematic in that the heat shrinkage in the desired direction is insufficient and the heat shrinkage in the direction orthogonal to the direction cannot be reduced. However, such a problem is caused by, for example, Japanese Patent Laid-Open No. 63-63.
This can be solved by optimizing the copolymerization composition of the raw material polyester resin, as disclosed in, for example, No. 156833. However, the films obtained by these methods also have a problem that the shrinking speed is too fast, for example, and defects such as wrinkles, distortions, shrinkage spots, and partial whitening of the film when heat-shrinked are beautiful. There is a drawback that it is difficult to obtain a good appearance. Further, since the above-mentioned conventional film is an insulator, it has a drawback that static electricity is likely to be generated and accumulated, causing various troubles due to electrostatic damage. For example, in the printing process, tubing process, label mounting process, etc., winding around a roll, electric shock to the human body, reduction in production efficiency such as difficulty in handling, occurrence of print mustache, poor opening of mouth, film surface There was a drawback that it could cause a decrease in product value such as dirt on the product.

[0004]

SUMMARY OF THE INVENTION The present invention is to solve the above-mentioned problems of the prior art. The object of the present invention is to make the heat shrinkage sufficiently large and to shrink uniformly. A heat-shrinkable polyester type that gives a beautiful appearance without defects such as wrinkles, distortion, shrinkage spots, and partial whitening of the film when exposed to electricity, and has excellent antistatic properties, and less troubles due to static electricity. To provide a film.

[0005]

The heat-shrinkable polyester film of the present invention has a heat shrinkage at 100 ° C. of 40% or more (primary heat shrinkage) in the main shrinking direction (main shrinking direction). A heat-shrinkable polyester film having a heat shrinkage ratio of 20% or less in a direction orthogonal to the main shrinkage direction, and the main shrinkage direction is heated in hot air at 100 ° C. for 10 seconds to shrink by 40% and then 130 The heat shrinkage rate (secondary heat shrinkage rate) when treated for 10 seconds in hot air at ℃ is 12% or more, and the surface resistivity of the film is 1 × 10 ¹³ Ω / mouth or less. It is an antistatic heat-shrinkable polyester film. As the dicarboxylic acid component constituting the polyester contained in the composition used in the thermoplastic polyester film of the present invention, in addition to terephthalic acid constituting the ethylene terephthalate unit, aromatic dicarboxylic acid, aliphatic dicarboxylic acid and alicyclic dicarboxylic acid Any of these can be used. As aromatic dicarboxylic acids, benzenedicarboxylic acids such as isophthalic acid, orthophthalic acid, and 5-tert-butylisophthalic acid;
Naphthalenedicarboxylic acids such as 6-naphthalenedicarboxylic acid; 4,4'-dicarboxydiphenyl, 2,2
Dicarboxybiphenyls such as 6,6-tetramethylbiphenyl-4,4'-dicarboxylic acid; 1,1,3-trimethyl-3-phenylindene-4,5-dicarboxylic acid and substituted compounds thereof; 1,2- Diphenoxyethane-
4,4'-dicarboxylic acid and its substitution products.
Examples of the aliphatic dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, pimelic acid, suberic acid, undecanoic acid, dodecanedicarboxylic acid, brassic acid, tetradecanedicarboxylic acid, and tapsinic acid. , Nonadecane dicarboxylic acid, docosane dicarboxylic acid, and substitution products thereof, 4,4′-dicarboxycyclohexane and substitution products thereof.

As the diol component of the polyester contained in the above composition, there is ethylene glycol which constitutes a polyethylene terephthalate unit, and in addition to this, any of aliphatic diol, alicyclic diol and aromatic diol can be used. Examples of the aliphatic diol include diethylene glycol propylene glycol, butanediol, 1,6-hexanediol, 1,10-decanediol, neopentyl glycol, 2-methyl-2-ethyl-1,3-propanediol, 2-diethyl- 1,3
-Propanediol, 2-ethyl-2-n-butyl-
1,3-propanediol and the like. As the alicyclic diol, 1,3-cyclohexanedimethanol, 1,
4-cyclohexanedimethanol and the like. Aromatic dicarboxylic acids include 2,2-bis (4'-β-hydroxyethoxydiphenyl) propane and bis (4'-β-
Ethylene oxide adducts of bisphenol compounds such as hydroxyethoxyphenyl) sulfone; polyalkylene glycols such as xylylene glycol, polyethylene glycol and polypropylene glycol.

The polyester contained in the composition used in the film of the present invention may be formed from the above-mentioned acid component and diol component. In order to prepare a polyester, it is usually preferable to use one or more acid components or diol components in combination, which can improve the properties as a heat-shrinkable film. The type and content of the monomer components used in combination can be appropriately determined based on desired film properties, economic efficiency and the like.

The heat-shrinkable polyester film of the present invention is a heat-shrinkable polyester film comprising a composition containing at least one polyester as described above, and the total polyester content is 40 to 90 mol. %
Is preferably an ethylene terephthalate unit. Any of the polyesters contained in the above composition can be produced by a conventional method. For example, a (copolymerization) polyester is prepared by a direct esterification method in which a dicarboxylic acid and a diol are directly reacted; a transesterification method in which a dicarboxylic acid dimethyl ester and a diol are reacted. The preparation may be performed by either a batch method or a continuous method.

In general, since the copolyester has a low melting point, there is a problem that it is difficult to handle when dried. It is preferable to use a mixture of copolyesters. In particular, the method of mixing polyethylene terephthalate and the copolyester is preferable from the economical point of view because polyethylene terephthalate can be obtained at a low cost. The composition is preferably amorphous and has a glass transition point of 50 ° C. or higher.

The polyester composition constituting the film of the present invention contains various additives as required in addition to the above polyester. Examples thereof include lubricants such as titanium dioxide, finely divided silica, kaolin, calcium carbonate, antiaging agents, ultraviolet ray inhibitors, and colorants (dyes, etc.). The intrinsic viscosity when the above polyester and various components of the polyester composition containing various additives as required are mixed is preferably 0.50 to 1.3 d / g. In the heat-shrinkable polyester film of the present invention, the heat shrinkage at 100 ° C. (primary heat shrinkage) in the seed shrinking direction needs to be 40% or more. If the shrinkage ratio is less than 40%, when the film is attached to the surface of the irregularly-shaped package and heat-shrinked, the required shrinkage in each part cannot be achieved, and in order to achieve the above-described shrinkage, high temperature is required. Will have to heat up. However, the heat resistance of the packaged object is also limited, and the range of application is narrowed by itself, which is not preferable.

In the present invention, the thermal shrinkage at 100 ° C. in the direction orthogonal to the main shrinkage direction must be 20% or less. It is preferably 15% or less, more preferably 10% or less. A film having such a shrinkage ratio of more than 20% is not preferable because, for example, when it is shrunk as a label, the film is greatly shrunk along the longitudinal direction of the container, causing distortion and curling of the end portion. Furthermore, the film of the present invention has a main shrinkage direction of 10 ° C. in hot air at 100 ° C.
After heating for 40 seconds and shrinking by 40%, the heat shrinkage rate (secondary shrinkage rate) is 14% when treated for 10 seconds in hot air at 130 ° C.
It is necessary to be above. When the heat shrinkage ratio is less than 14%, defects such as wrinkles, distortions and shrinkage spots occur in the film when heat-shrinked, and a beautiful appearance cannot be obtained, which is not preferable.

The above polyester composition is formed into a film by a known method (eg, extrusion method, calender method). The shape of the film is, for example, a plane shape or a tube shape, and is not particularly limited. The obtained film is stretched in a predetermined direction (main stretching direction) in a range of 2.5 times to 7.0 times, preferably 3.0 times to 6.0 times under predetermined conditions described below. To be done. It is more preferably 4.0 times to 6.0 times, and most preferably 4.5 times to 6.0 times. It is stretched in the direction orthogonal to the machine direction in the range of 1.0 to 2.0 times, preferably 1.1 to 1.8 times. Either may be first in the order of this stretching. Stretching in the main stretching direction is performed to obtain a high heat shrinkage ratio in this direction. By stretching in the direction orthogonal to the main stretching direction, the impact resistance of the obtained film is improved and the property of being easily torn in one direction is relaxed. When the stretching ratio in the right-angled direction exceeds 2 times, the heat-shrinkability in the direction orthogonal to the main shrinkage direction becomes too large, and the finish when heat-shrinked becomes uneven in a wavy state. The film stretched at the above ratio usually has a shrinkage ratio of 15 in the direction orthogonal to the shrinkage ratio in the main direction.
% Or less, preferably 8 to 9% or less, more preferably 7
% Or less. Such a film has a uniform finish when subjected to heat treatment.

As a stretching method, a usual method is adopted. Examples thereof include roll stretching method, long gap stretching method, tenter stretching method, and tubular stretching method. In any of these methods, the stretching is performed by sequential biaxial stretching and simultaneous biaxial stretching.
Axial stretching, uniaxial stretching, and combinations thereof can be performed. In the above-mentioned biaxial stretching, stretching in the longitudinal and transverse directions may be performed simultaneously, but sequential biaxial stretching in which either one is performed first is effective, and the longitudinal and lateral directions may be performed first. Preferably, the above stretching is performed in the following steps. For example, first, the film is preheated at a temperature not lower than the average glass transition temperature (Tg) of the polymer constituting the film, for example, Tg + 80 ° C. or lower. When preheating is performed in the above temperature range during stretching in the main direction (main shrinkage direction), heat shrinkage in the direction orthogonal to the direction can be suppressed.
Moreover, by performing the heating within the temperature range of 80 ± 25 ° C., the heat shrinkage ratio in the orthogonal direction becomes almost minimum. During these stretching, heat setting is usually performed. For example, it is recommended to pass a heating zone at 30 ° C to 150 ° C for about 1 to 30 seconds after stretching. By performing heat setting, dimensional change of the obtained film under high temperature in summer can be prevented. The stretching may be performed to a predetermined degree after the film is stretched and before or after the heat setting. In that case, the film length is 70
Elongation is performed at a rate of up to%. In particular, it extends in the main direction and is in the non-contracting direction (direction orthogonal to the main contracting direction).
It is better not to extend. Furthermore, after the stretching,
Shrinking of the obtained film by heating by adding a step of cooling the film while applying tension to the film while keeping it in a stretched or tensioned state, or a step of subsequently cooling the film after releasing the tensioned state after the treatment. The characteristics are better and more stable.

The plane orientation coefficient of the film thus obtained is preferably 100 × 10 ^-3 or less. When the surface orientation coefficient exceeds 100 × 10 ⁻³ , the strength is lowered and the surface is liable to be broken even by a small amount of external damage. For example, even if it is wrapped around the outer surface of a bottle and used as a reinforcing material, the reinforcing effect is low. The birefringence is preferably 15 × 10 ^{−3 to} 160 × 10 ⁻³ . When the birefringence is less than 15 × 10 ⁻³ , the shrinkage rate and shrinkage stress in the main shrinkage direction are low. On the other hand, if it exceeds 160 × 10 ⁻³ , it is easily broken by external damage and the impact strength is low, so that it is not practical. The resulting film thickness is 6
The range of ˜250 μm is preferable.

Another major constituent requirement of the present invention is that the surface resistivity of the film is 1 × 10 ¹³ Ω / port or less. It is preferably 1 × 10 ¹² Ω / port or less. The surface resistivity of the film is 1 × 10 ¹³ Ω /
If you pass over the mouth, the film will be easily charged and static electricity will be generated.
Accumulation is likely to occur, which causes various troubles due to electrostatic damage, which is not preferable. For example, in the printing process, tubing process, label device process, etc., winding around a roll, electric shock to the human body, reduction in work efficiency such as difficulty in handling, occurrence of print mustache, poor opening of mouth, stain on film surface It causes the decrease of the product value. The film surface resistivity is 1 × 10 ¹³ Ω /
In order to make it less than or equal to the mouth, (1) an antistatic agent is added to the above polyester composition to produce a film. This can be achieved by (2) applying an antistatic agent to the surface of the film in the above-described film production step, or (3) applying an antistatic agent to the surface of the film produced by the above method.

The antistatic agent is not limited at all, and any type of nonionic, anionic, cationic and amphoteric antistatic agents may be used, or these antistatic agents may be used in combination. Further, it may be a low molecular weight type or a high molecular weight type. When the method (1) is carried out, the heat resistance of the antistatic agent is required, so it is preferable to use a nonionic or anionic antistatic agent. Further, as the antistatic agent for carrying out the methods (2) and (3) described above, it is preferable to use an ionic antistatic agent which exhibits an effect even when applied in a small amount. When the method (2) or (3) is carried out, the antistatic agent may be applied alone, or may be diluted with a solvent or dissolved and applied.
A method of coating by diluting or dissolving with a solvent is preferable from the viewpoint of forming a uniform coating film. An organic solvent having a boiling point as low as possible is preferably used as a solvent for coating by this method.
It is a preferred embodiment to use lower alcohols.

EXAMPLES The present invention will be described below with reference to examples. The measuring method used in the examples is as follows. (1) Primary heat shrinkage rate The film is cut into a width of 15 mm to form a sample, and a marked line is drawn in a gap of 200 mm in the longitudinal direction. This sample is heated by applying hot air at a predetermined temperature (100 ° C.) for 1 minute to measure the shrinkage rate.

(2) Secondary heat shrinkage ratio The film was fixed to a metal frame with a slack of 40% with respect to the film width in the main shrinkage direction, and heated in hot air at 100 ° C. for 10 minutes.
Heat for 2 seconds to shrink the film 40%. The heat-shrinked film is cut into a piece having a width of 15 mm, and the lengthwise direction is 200 m.
Mark lines at intervals of m. This sample is treated in hot air at 130 ° C. for 10 seconds, and the shrinkage rate is measured.

(3) The shrink-finished film was metallically printed as a shrink label and tubed into a cylindrical shape, and then covered with a rectangular PET bottle of 1.5 and passed through a shrink tunnel. The condition of the shrink tunnel is 100 ° C in the first zone and the residence time is 4.5.
Second, the second zone was 140 ° C. and the residence time was 5 seconds. The finish of shrinkage of the obtained label was visually judged with respect to wrinkles, print distortion, and print density due to shrinkage unevenness.

(4) Surface specific resistance: Takeda Riken specific resistance measuring instrument applied voltage of 500 V, 2
It was measured under the conditions of 3 ° C. and 50% RH.

Example 1 95 mol% of terephthalic acid as dicarboxylic acid, 5 mol% of adipic acid, and ethylene glycol 6 as diol component
8 mol%, diethylene glycol 2 mol%, cyclohexanedimethanol 30 mol%, average particle size 2.4
0.05% by weight of silicon dioxide of μm and sodium chain alkyl sulfonate (Atrai AS- manufactured by Nippon Mining Co., Ltd.)
1000) Including 0.5% by weight, intrinsic viscosity 0.70d
1 / g of copolyester was melt extruded at 290 ° C. to obtain a film having a thickness of 200 μm. This unstretched film was preheated at 120 ° C. for 6 seconds and then stretched 5.0 times in a predetermined direction. The temperature conditions during the stretching were set to 80 ° C. in half of all steps and to 90 ° C. in the other half. After stretching, heat treatment was performed at 95 ° C. for 5 seconds. At the time of this heat treatment, relaxation treatment of 3% in the lateral direction and 0.2% in the longitudinal direction was performed to obtain a heat-shrinkable film of 40 μm. The properties of the heat-shrinkable film thus obtained are shown in Table 1. The heat-shrinkable film obtained in this example had a high secondary heat-shrinkability, a shrinkable finish as a shrinkable label was good, and it was highly practical. In addition, the heat-shrinkable film has excellent antistatic property, and causes various troubles due to electrostatic damage such as winding around a roll, occurrence of print whiskers, and poor opening of mouth in a printing process, a tubing process, a label mounting process, or the like. The work efficiency was high, and even when the product was displayed in the store for a long period of time, there was little surface stain on the film, and the handleability and product value were both high.

Comparative Example 1 Table 1 shows the properties of the heat-shrinkable film obtained by the same method as in Example 1 except that the linear sodium sulfonate was not added. The heat-shrinkable film obtained in this comparative example has a high secondary shrinkability and a good shrink finish as a shrink label, but is inferior in antistatic property, and is not suitable for printing process, tubing process or label mounting process. Various troubles occurred due to static electricity troubles such as winding around a roll, occurrence of print whiskers, and poor opening of the mouth, resulting in a decrease in work efficiency and poor handleability.

Comparative Example 2 83 mol% of terephthalic acid as a dicarboxylic acid component, 14 mol% of isophthalic acid, 3 mol% of sebacic acid, 97 mol% of ethylene glycol as a glycol component, 3 mol% of diethylene glycol, and an average particle diameter of 2.4 μm. 0.05% by weight of silicon dioxide and straight chain alkyl sulfonic acid soda (Atrai AS1000 manufactured by Nippon Mining Co., Ltd.)
A copolyester having an intrinsic viscosity of 0.70 dl / g containing 0.5% by weight was melt extruded at 290 ° C. and a thickness of 172
A film of μm was obtained. This unstretched film was preheated at 120 ° C. for 6 seconds and then stretched 4.3 times in a predetermined direction. The temperature condition during stretching was 65 ° C in all steps. After stretching, heat treatment was performed at 82 ° C. for 5 seconds. At the time of this heat treatment, relaxation treatment of 3% in the transverse direction and 0.2% in the longitudinal direction was performed to obtain a heat-shrinkable film of 40 μm. The properties of the heat-shrinkable film thus obtained are shown in Table 1. The heat-shrinkable polyester film obtained in this comparative example was excellent in antistatic property and was used in Example 1
The film was excellent in handleability similarly to the film No. 1, but had a low secondary heat shrinkability, and the shrinkage as a shrinkable label was poor and the practicability was low.

Example 2 90 mol% of terephthalic acid as a dicarboxylic acid component, 10 mol% of sebacic acid, 48 mol% of ethylene glycol as a glycol component, 2 mol% of diethylene glycol, and 50 mol% of neopentyl glycol having an intrinsic viscosity of 0.65 dl. 60% by weight of copolyester / g,
Polyethylene terephthalate 4 containing 0.125% by weight of silicon dioxide having an average particle diameter of 2.4 μm and 1.25% by weight of linear alkyl sulfonate sodium (Atrai AS1000 manufactured by Nippon Mining Co., Ltd.) and an intrinsic viscosity of 0.75 dl / g.
Table 1 shows the characteristics of the heat-shrinkable film obtained in the same manner as in Example 1 by using the composition of 0% by weight. Like the heat-shrinkable film obtained in Example 1, the heat-shrinkable film obtained in this Example has high secondary shrinkability, and has a good shrink finish as a shrink label and is highly practical. there were. Further, the heat-shrinkable film obtained in this example has excellent antistatic property like the heat-shrinkable film obtained in Example 1 and is easy to handle as a shrinkable label and has little dust adhesion due to static electricity. The value was high.

Comparative Example 3 Table 1 shows the characteristics of the heat-shrinkable film obtained in the same manner as in Example 2 except that polyethylene terephthalate to which the linear sodium sulfonate was not added was used. The heat-shrinkable film obtained in this Comparative Example has a good finish as a shrinkable label similarly to the film obtained in Comparative Example 1, but is inferior in antistatic property and poor in handleability as a shrinkable label. there were.

Example 3 90 mol% of terephthalic acid as a dicarboxylic acid component, 10 mol% of azelaic acid, 48 mol% of ethylene glycol as a glycol component, 2 mol% of diethylene glycol,
An intrinsic viscosity of 25 mol% neopenterglycol and 25 mol% 1,4-cyclohexanedimethanol has an intrinsic viscosity of 0.6.
Polyethylene terephthalate 50 having an intrinsic viscosity of 0.75 dl / g, containing 50 mol% of 5 dl / g copolymerized polyester and 0.10% by weight of silicon dioxide having an average particle size of 2.4 μm
A heat-shrinkable film was obtained in the same manner as in Example 1 except that the composition of wt% was used. The heat-shrinkable polyester film was used in a printing machine to obtain oleic acid methyl ester 0.05% by weight and polyoxyethylene alkylamine 0.05% by weight.
And about 6 g of an ethanol solution containing an antistatic agent consisting of 0.04% by weight of alkyl trimethyl ammonium salt
After coating with a coating amount of m ² , it was dried at a temperature of 50 ° C. The properties of the heat-shrinkable film coated with the obtained antistatic agent are shown in Table 1. The heat-shrinkable film obtained in this example is the same as that in Example 1.
Similar to the heat-shrinkable film obtained in 1., the secondary shrinkability was high, the shrinkable finish as a shrinkable label was good, and the practicability was high. Further, like the heat-shrinkable film obtained in this example, it was excellent in antistatic property, and was easy to handle as a shrinkable label and had little dust adhesion due to static electricity and had a high commercial value.

Comparative Example 4 Table 1 shows the characteristics of the heat-shrinkable film obtained by the same method as in Example 3 except that the application of the antistatic agent was stopped in the method of Example 3. The heat-shrinkable film obtained in this Comparative Example has a good finish as a shrinkable label similarly to the film obtained in Comparative Example 1, but is inferior in antistatic property and poor in handleability as a shrinkable label. there were.

[0028]

EFFECT OF THE INVENTION The shrink film of the present invention is a film which gives a beautiful appearance with very few defects such as wrinkles, distortions and shrinkage spots when heat-shrinked, and is excellent in antistatic property. There are few troubles due to the generation of static electricity, for example, it has excellent handleability and is useful in a wide range of packaging material fields including shrink films for labels.
High utility value.

[0029]

[Table 1]

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[Procedure amendment]

[Submission date] June 23, 1993

[Procedure Amendment 1]

[Document name to be amended] Statement

[Name of item to be amended] Claims

[Correction method] Change

[Correction content]

[Claims]

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Shinichiro Okumura 344 Maebata, Kizu character, Inuyama City, Aichi Prefecture Toyobo Co., Ltd. Inuyama Factory

Claims (1)

[Claims] 1. The heat shrinkage ratio at 100 ° C. is 40% or more (primary heat shrinkage ratio) in the main shrinkage direction (main shrinkage direction), and the heat shrinkage ratio in the direction orthogonal to the main shrinkage direction is 20.
% Of the heat-shrinkable polyester film,
Main shrinkage direction is heated in hot air at 100 ° C for 10 seconds to 40%
An antistatic heat-shrinkable polyester film having a heat shrinkage (secondary heat shrinkage) of 12% or more and a surface specific resistance of the film of 1 × 10 ¹³ Ω / port or less.