JP2009000898A - Heat-shrinkable multilayer film and heat-shrinkable label - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-shrinkable multilayer film achieving excellent shrinkage finish property without causing defects such as wrinkles, distortion of a print pattern and shrinkage unevenness when used as a heat-shrinkable label for dry heat shrinkage, and to provide the heat-shrinkable label using the heat-shrinkable multilayer film as a base film. <P>SOLUTION: The heat-shrinkable multilayer film is formed by laminating an outer surface layer including polyester resin, through an intermediate layer including a polystyrene resin, wherein a Vicat softening temperature (Vt1) of the polyester resin and a Vicat softening temperature (Vt2) of the polystyrene resin satisfy an expression Vt1≤Vt2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

The present invention, when used as a heat-shrinkable label for dry heat shrinkage, can realize excellent shrink finish without causing problems such as wrinkles, printed pattern distortion and shrinkage unevenness after mounting. The present invention relates to a heat shrinkable multilayer film and a heat shrinkable label using the heat shrinkable multilayer film as a base film.

In recent years, many containers such as plastic bottles and metal bowls are equipped with a heat-shrinkable label obtained by printing a base film made of a heat-shrinkable resin film. As a method for heating a heat-shrinkable label and attaching it to a container, two kinds of methods, wet heat shrinkage and dry heat shrinkage, are widely used.

The wet heat shrinkage is a method in which the heat-shrinkable label is shrunk by heating with water vapor and is attached to the container. Since water vapor has a high thermal conductivity, a sufficient amount of heat can be given to the heat-shrinkable resin film in a short time, and the label mounting speed can be greatly increased. In addition, since heat unevenness in the atmosphere is unlikely to occur, printed pattern distortion and wrinkles seen after mounting are small, and the shrink finish is excellent.

On the other hand, dry heat shrinkage is a method in which a heat-shrinkable label is shrunk by heating using hot air and mounted on a container. Dry heat shrinkage is superior in terms of hygiene because it does not use water vapor compared to wet heat shrinkage. Moreover, compared with wet heat shrinkage, it has the advantage that it can be shrink-fitted with simple equipment. Therefore, when mounting on a container with a small number of lots, or when mounting a heat-shrinkable label on a container before filling the contents, mounting by dry heat shrinkage is generally performed.

As a heat-shrinkable label used when mounting by dry heat shrinkage, one made of a polystyrene resin is mainstream because of its excellent low-temperature shrinkage. However, the polystyrene-based resin film has a problem that since the rigidity of the film is low, the suitability for a machine is poor, and problems such as label clogging are likely to occur. In addition, since the polystyrene-based resin film has insufficient solvent resistance, there is a problem that when it is used for packaging an article containing oil, it may shrink or dissolve due to adhesion of the oil. It was.

On the other hand, an attempt has been made to use a polyester film excellent in heat resistance and solvent resistance as a heat shrinkable label in place of the polystyrene resin film. However, the polyester film has poor low-temperature shrinkability, and has a problem that printing pattern distortion and wrinkles are likely to occur when the polyester film is attached to a container. In addition, the heat-shrinkable label is often provided with a perforation for peeling so that the heat-shrinkable label can be easily peeled off from the used container in order to recycle the container. The system film has a problem in that the cut property at the perforation is poor and the heat-shrinkable label cannot be easily peeled off from the container.

On the other hand, Patent Document 1 discloses a hard multilayer shrinkable film in which an outer layer made of a polyester resin is laminated on an intermediate layer made of a polystyrene resin through an adhesive layer made of an olefin resin. ing. In Patent Document 2, an outer surface layer made of a polyester resin made of a specific monomer is laminated on both sides of an intermediate layer made of a polystyrene resin, and the intermediate layer and the outer surface layer form an adhesive layer. A heat-shrinkable label having a base film laminated without being interposed is disclosed. Furthermore, Patent Document 3 discloses a laminated film having a surface layer made of a polyester resin, an intermediate layer made of a styrene resin, and an adhesive layer made of an adhesive resin.

However, when these heat-shrinkable labels are attached to the container by dry heat shrinkage, the shrinkage behavior of the layer made of polystyrene resin and the layer made of polyester resin is greatly different. There has been a problem that defects such as shrinkage unevenness occur. Therefore, when used as a heat-shrinkable label for dry heat shrinkage, there is a need for a heat-shrinkable multilayer film having a high shrink finish without causing problems such as wrinkles, printed pattern distortion, and shrinkage unevenness after mounting. It was done.
JP 61-41543 A JP 2002-351332 A JP 2006-15745 A

In view of the above situation, the present invention, when used as a heat-shrinkable label for dry heat shrinkage, exhibits excellent shrinkage finish without occurrence of defects such as wrinkles, printed pattern distortion, and shrinkage unevenness after mounting. It is an object of the present invention to provide a heat-shrinkable multilayer film capable of realizing the above and a heat-shrinkable label using the heat-shrinkable multilayer film as a base film.

The present invention is a heat-shrinkable multilayer film in which an outer surface layer containing a polyester resin is laminated via an intermediate layer containing a polystyrene resin, and the Vicat softening temperature (Vt1) of the polyester resin and the polystyrene The Vicat softening temperature (Vt2) of the resin is a heat shrinkable multilayer film that satisfies the following formula (1).

以下に本発明を詳述する。

The present invention is described in detail below.

In the heat-shrinkable multilayer film in which an outer surface layer containing a polyester-based resin is laminated via an intermediate layer containing a polystyrene-based resin, the present inventors have a polyester-based resin and a polystyrene-based resin having a predetermined Vicat softening temperature. By using resin, when used as a heat-shrinkable label for dry heat shrinkage, heat shrinkage that prevents wrinkles, printed pattern distortion, shrinkage unevenness, etc. after mounting and has excellent shrinkage finish As a result, the present invention has been completed.

In the heat-shrinkable multilayer film of the present invention, an outer surface layer containing a polyester resin is laminated via an intermediate layer containing a polystyrene resin, the Vicat softening temperature (Vt1) of the polyester resin, and the above The Vicat softening temperature (Vt2) of the polystyrene resin satisfies the following formula (1).

When the Vicat softening temperature of the polyester resin and polystyrene resin satisfies the relationship of the above formula (1), when mounting is performed by dry heat shrinkage, the outer surface layer is softened first, and at the same time or thereafter The layer softens. Thereby, the shrinkage behavior of the heat-shrinkable multilayer film of the present invention is close to that of a single film of polystyrene resin having a high shrinkage finish, and the occurrence of defects such as wrinkles and printed pattern distortion can be prevented.
If the relationship of the above formula (1) is not satisfied, there are problems such as biting wrinkles and printed pattern distortion, or shrinkage unevenness in the circumferential direction becomes large when mounting by dry heat shrinkage. Occurs and shrink finish is reduced.
Moreover, in this invention, it is preferable that Vt2-Vt1 is 30 degrees C or less, satisfying the relationship of said Formula (1), More preferably, it is 25 degrees C or less, It is still more preferable that it is 21 degrees C or less. If it exceeds 30 ° C., the difference in shrinkage start temperature between the outer surface layer and the intermediate layer becomes large, and the shrinkage finish may be deteriorated.
The Vicat softening temperature can be measured by a method based on JIS K 7206 (1999).

The preferable lower limit of the Vicat softening temperature (Vt1) of the polyester resin is 60 ° C., and the preferable upper limit is 80 ° C. If it is lower than 60 ° C., shrinkage may start at a low temperature. In addition, the shrinkage rate decreases with time. If it exceeds 80 ° C., the shrinkage start temperature may increase.

The preferable lower limit of the Vicat softening temperature (Vt2) of the polystyrene resin is 60 ° C, and the preferable upper limit is 90 ° C. If it is lower than 60 ° C., shrinkage may be started at a low temperature or the natural shrinkage rate may be increased. In addition, the shrinkage rate decreases with time. If it exceeds 90 ° C, the shrinkage start temperature may increase. A more preferred upper limit is 85 ° C, and a still more preferred upper limit is 83 ° C.

The polyester resin constituting the outer surface layer can be obtained by condensation polymerization of dicarboxylic acid and diol.
The dicarboxylic acid is not particularly limited. For example, o-phthalic acid, terephthalic acid, isophthalic acid, succinic acid, adipic acid, sebacic acid, azelaic acid, octyl succinic acid, cyclohexanedicarboxylic acid, naphthalenedicarboxylic acid, fumaric acid, Examples include maleic acid, itaconic acid, decamethylene carboxylic acid, anhydrides and lower alkyl esters thereof.
The diol is not particularly limited. For example, ethylene glycol, 1,3-propanediol, 1,4-butanediol, diethylene glycol, 1,5-pentanediol, 1,6-hexanediol, dipropylene glycol, triethylene Glycol, tetraethylene glycol, 1,2-propanediol, 1,3-butanediol, 2,3-butanediol, neopentyl glycol (2,2-dimethylpropane-1,3-diol), 1,2-hexane Aliphatic diols such as diol, 2,5-hexanediol, 2-methyl-2,4-pentanediol, 3-methyl-1,3-pentanediol, 2-ethyl-1,3-hexanediol; 2-bis (4-hydroxycyclohexyl) propane, 2,2-bis (4-hydroxy) B carboxymethyl cyclohexyl) alkylene oxide adducts of propane, 1,4-cyclohexane diol, alicyclic diols such as 1,4-cyclohexanedimethanol.

Among these polyester resins, those containing a component derived from terephthalic acid as the dicarboxylic acid component and a component derived from ethylene glycol and 1,4-cyclohexanedimethanol as the diol component are preferred. By using such a polyester-based resin, particularly high heat resistance and solvent resistance can be imparted to the resulting heat-shrinkable multilayer film of the present invention.
In addition, when imparting particularly high heat resistance and solvent resistance, the content of the component derived from ethylene glycol is 60 to 80 mol%, and the content of the component derived from 1,4-cyclohexanedimethanol is 10 to 10. It is preferable to use one that is 40 mol%. Such a polyester resin may further contain 0 to 20 mol% of a component derived from diethylene glycol.
As a polyester-type resin which comprises the said outer surface layer, the polyester-type resin which has the composition mentioned above may be used independently, and 2 or more types of polyester-type resins which have the composition mentioned above may be used together.

As the polyester resin, a resin having a crystal melting temperature of 240 ° C. or lower is preferably used. In the manufacture of heat-shrinkable labels, it is common practice to use trimmed pieces of stretched ears and recycled films as return materials again. Usually, such a return material is mixed with a polystyrene resin as a raw material for the intermediate layer. However, since the polystyrene resin and the polyester resin have different properties such as a melting point, the temperature is suitable for molding the polystyrene resin. When film molding is performed, the polyester resin may be extruded in an unmelted state. However, by using a polyester resin having a relatively low crystal melting temperature or no crystal melting temperature, it is possible to prevent an unmelted product of the polyester resin from becoming a foreign substance in the film after molding. On the other hand, when the crystal melting temperature exceeds 240 ° C., when molding as a return material, undissolved polyester-based resin remains as foreign matter on the film, resulting in appearance failure or ink at the time of printing. In some cases, a problem such as a printing failure occurs due to flying. More preferably, it is 220 degrees C or less.

Examples of the polystyrene resin constituting the intermediate layer include an aromatic vinyl hydrocarbon-conjugated diene copolymer, or an aromatic vinyl hydrocarbon-conjugated diene copolymer and an aromatic vinyl hydrocarbon-aliphatic unsaturated. Examples thereof include a mixed resin with a carboxylic acid ester copolymer.
When the above aromatic vinyl hydrocarbon-conjugated diene copolymer is used, a heat-shrinkable multilayer film with little decrease in elongation under a low temperature atmosphere is obtained.
In addition, when a mixed resin of an aromatic vinyl hydrocarbon-conjugated diene copolymer and an aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer is used, a heat-shrinkable multilayer film excellent in low-temperature shrinkability and Become.

The aromatic vinyl hydrocarbon-conjugated diene copolymer is not particularly limited. For example, aromatic vinyl hydrocarbons include styrene, o-methylstyrene, p-methylstyrene and the like, and conjugated dienes are 1,3- Examples include butadiene, 2-methyl-1,3-butadiene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, and the like. These may be used alone or in combination of two or more. Among these, a styrene-butadiene-styrene copolymer (SBS resin) is preferable because it is particularly excellent in low-temperature shrinkage and cut performance at perforations. In order to produce a film with less fish eye, a styrene-isoprene-styrene copolymer (SIS resin) using 2-methyl-1,3-butadiene (isoprene) as a conjugated diene, or a styrene-isoprene. It is preferable to use a butadiene-styrene copolymer (SIBS resin) or the like.

When the SBS resin, SIS resin or SIBS resin is used as the aromatic vinyl hydrocarbon-conjugated diene copolymer, one kind of resin may be used alone, or a plurality of resins may be used in combination. . When used in plural, dry blending may be used, or a compound resin that is kneaded and pelletized using an extruder with a specific composition may be used.
It is preferable to use such resins singly or in combination to have a composition having a styrene content of 65 to 90% by weight and a conjugated diene content of 10 to 35% by weight. A resin having such a composition is particularly excellent in low-temperature shrinkage and perforation. On the other hand, when the conjugated diene content is less than 10% by weight, the film is easily cut when tension is applied to the film, and the film may break unexpectedly when used as a converting or label for printing or the like. . When the conjugated diene content exceeds 35% by weight, foreign matters such as gel may be easily generated during the molding process.

The aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer is not particularly limited, and examples of the aromatic vinyl hydrocarbon include styrene, o-methylstyrene, p-methylstyrene, and the like. Examples of the acid ester include methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, and butyl methacrylate. These may be used alone or in combination of two or more.

When a styrene-butyl acrylate copolymer is used as the aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer, the styrene content is 60 to 90% by weight, and the butyl acrylate content is 10 to 40. It is preferable to use what is weight%. By using the aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer having such a composition, a heat-shrinkable label having excellent shrinkage finishing properties and perforation cutting properties can be obtained.

When a mixed resin of an aromatic vinyl hydrocarbon-conjugated diene copolymer and an aromatic vinyl hydrocarbon-aliphatic unsaturated carboxylic acid ester copolymer is used as the intermediate layer, the aromatic vinyl carbonization in the mixed resin is used. The preferable lower limit of the blending amount of the hydrogen-conjugated diene copolymer is 20% by weight, and the preferable upper limit is 100% by weight. If it is less than 20% by weight, the low-temperature elongation becomes low, and the heat-shrinkable label may be broken when it is accidentally dropped during refrigerated storage. A more preferred lower limit is 30% by weight.

The Vicat softening temperature of the polystyrene resin is adjusted by copolymerizing an aromatic vinyl hydrocarbon with a conjugated diene or an aliphatic unsaturated carboxylic acid ester component. Even if the conjugated diene or the aliphatic unsaturated carboxylic acid ester is a polystyrene resin having the same weight ratio, it takes a random (or tapered) copolymer structure, a block copolymer structure, or these The Vicat softening temperature varies depending on the mixed structure. In general, random (or tapered) copolymers tend to have lower Vicat softening temperatures than block copolymers when the ratio of aromatic vinyl hydrocarbons to conjugated dienes or aliphatic unsaturated carboxylic acid ester components is the same. It is in. In addition, in the case of having both a block copolymer structure and a random (or tapered) copolymer structure, the larger the ratio of the random (or tapered) copolymer, the lower the Vicat softening temperature, and the random (or tapered) ) If the ratio of the copolymer is small, the Vicat softening temperature becomes high.

In the heat-shrinkable multilayer film of the present invention, the intermediate layer can contain an ultraviolet absorber. In this way, by containing an ultraviolet absorber, it is possible to impart ultraviolet cut-off properties, and in particular, excellent cut-off properties of ultraviolet rays (wavelength of 380 nm or less) emitted from sunlight or fluorescent lamps, so that the contents of the container are deteriorated. Can be prevented and storage can be improved.
Further, by including the ultraviolet absorber only in the intermediate layer containing the polystyrene resin, it is possible to solve problems such as thermal deterioration and roll contamination when the ultraviolet absorber is contained in the polyester resin. In addition, even when the content of the ultraviolet absorber is small, the desired ultraviolet cutting property can be achieved, which is advantageous in terms of cost.

The ultraviolet absorber is not particularly limited, and examples thereof include 2,4-dihydroxybenzophenone, 2,2 ′, 4,4′-tetrahydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, and 2-hydroxy-4-methoxy. Benzophenone ultraviolet absorbers such as benzophenone-5-sulfonic acid and 2-hydroxy-4-n-octoxybenzophenone; 2- (2′-hydroxy-4′-n-octoxyphenyl) benzotriazole, 2- (2 '-Hydroxy-5'-n-methoxyphenyl) benzotriazole, 2- (2'-hydroxy-3'-tert-butyl-5'-methylphenyl) -5-chlorobenzotriazole, 2- (2'-hydroxy) -3 ′, 5′-di-tert-butylphenyl) -5-chlorobenzotriazole, 2- (2′-hydride) Roxy-5′-tert-octylphenyl) benzotriazole, 2- [2′-hydroxy-3 ′-(3 ″, 4 ″, 5 ″, 6 ″ -tetrahydrophthalimidomethyl) -5′-methyl Benzotriazole ultraviolet absorbers such as phenyl] benzotriazole; benzoate ultraviolet absorbers such as 2,4-di-tert-butylphenyl-3,5-di-tert-butyl-4-hydroxybenzoate; p-tert- Examples thereof include salicylate ultraviolet absorbers such as butylphenyl salicylate; cyanoacrylate ultraviolet absorbers such as ethyl-2-cyano-3,3-diphenyl acrylate and octyl-2-cyano-3,3-diphenyl acrylate.
Among these, 2- (2′-hydroxy-5′-n-methoxyphenyl) benzotriazole and 2- (2′-hydroxy-3′-tert-butyl) are excellent in balance between ultraviolet absorption and heat resistance. -5'-methylphenyl) -5-chlorobenzotriazole is preferred.

The content of the ultraviolet absorber depends on the thickness of the intermediate layer, but the preferred lower limit is 1 part by weight and the preferred upper limit is 10 parts by weight with respect to 100 parts by weight of the material constituting the intermediate layer such as base resin and return material. It is. When the amount is less than 1 part by weight, the UV-cutting property becomes insufficient, and when used as a shrink label for a container, the content may not be prevented from being deteriorated. The mechanical strength decreases, and breakage or the like may occur when used as a converting or shrink label for printing or the like. The minimum with more preferable content of the said ultraviolet absorber is 2 weight part, and a more preferable upper limit is 8 weight part.

The heat-shrinkable multilayer film of the present invention preferably further has an adhesive layer between the outer surface layer and the intermediate layer. The resin constituting the adhesive layer is not particularly limited and commercially available adhesive resins can be used. Among them, styrene elastomers, polyester elastomers, or modified products thereof are preferable. Such an adhesive layer has a high affinity for either the polystyrene resin constituting the intermediate layer or the polyester resin constituting the outer surface layer, and can bond them with high strength. In addition, since it dissolves or swells in a solvent that dissolves the polyester resin constituting the outer surface layer, the solvent can penetrate into the interior of the shrink label during center sealing, and delamination occurs during subsequent heat shrinkage. Can be prevented. Furthermore, since it can be molded by the coextrusion method together with the intermediate layer and the outer surface layer, it is excellent in productivity. In addition, as resin which comprises the said contact bonding layer, the adhesive resin generally marketed other than the resin mentioned above can be used.

The styrenic elastomer includes those composed of polystyrene as a hard segment and polybutadiene, polyisoprene, a copolymer of polybutadiene and polyisoprene as a soft segment, and hydrogenated products thereof. The hydrogenated product may be one obtained by hydrogenating a part of polybutadiene or polyisoprene, or may be one obtained by hydrogenating all of them.

Examples of commercially available styrene elastomers include “Tuftec”, “Tufprene” (all manufactured by Asahi Kasei Chemicals), “Clayton” (manufactured by Kraton Polymer Japan), “Dynalon” (manufactured by JSR), “Septon”. (Made by Kuraray Co., Ltd.).

Examples of the modified styrenic elastomer include those modified with a functional group such as a carboxylic acid group, an acid anhydride group, an amino group, an epoxy group, and a hydroxyl group.
The preferred lower limit of the content of functional groups such as carboxylic acid groups, acid anhydride groups, amino groups, epoxy groups and hydroxyl groups in the modified styrene elastomer is 0.05% by weight, and the preferred upper limit is 5.0% by weight. It is. If it is less than 0.05% by weight, the adhesion to the outer surface layer may be insufficient, and if it exceeds 5.0% by weight, the resin is thermally deteriorated when the functional group is added, and the gel Such a foreign matter may be easily generated. A more preferred lower limit is 0.1% by weight, and a more preferred upper limit is 3.0% by weight.

The polyester elastomer is preferably a saturated polyester elastomer, and particularly preferably a saturated polyester elastomer containing a polyalkylene ether glycol segment. As the saturated polyester-based elastomer containing a polyalkylene ether glycol segment, for example, a block copolymer composed of an aromatic polyester as a hard segment and a polyalkylene ether glycol or an aliphatic polyester as a soft segment is preferable. Furthermore, a polyester polyether block copolymer having a polyalkylene ether glycol as a soft segment is more preferable.

The polyester polyether block copolymer includes (i) an aliphatic and / or alicyclic diol having 2 to 12 carbon atoms, and (ii) an aromatic dicarboxylic acid and / or an aliphatic dicarboxylic acid or an alkyl ester thereof. And (iii) polyalkylene ether glycol as a raw material, and those obtained by polycondensation of oligomers obtained by esterification reaction or transesterification reaction are preferred.

As said C2-C12 aliphatic and / or alicyclic diol, what is generally used as a raw material of a polyester, especially the raw material of a polyester-type elastomer can be used, for example. Specific examples include ethylene glycol, propylene glycol, trimethylene glycol, 1,4-butanediol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol and the like. Among these, 1,4-butanediol or ethylene glycol is preferable, and 1,4-butanediol is particularly preferable. These diols may be used alone or in combination of two or more.

As said aromatic dicarboxylic acid, what is generally used as a raw material of polyester, especially a polyester-type elastomer can be used. Specific examples include terephthalic acid, isophthalic acid, phthalic acid, and 2,6-naphthalenedicarboxylic acid. Among these, terephthalic acid or 2,6-naphthalenedicarboxylic acid is preferable, and terephthalic acid is particularly preferable. These aromatic dicarboxylic acids may be used alone or in combination of two or more.

Examples of the alkyl ester of the aromatic dicarboxylic acid include the dimethyl ester and diethyl ester of the aromatic dicarboxylic acid. Of these, dimethyl terephthalate and 2,6-dimethyl naphthalene dicarboxylate are preferable.

The aliphatic dicarboxylic acid is preferably cyclohexane dicarboxylic acid, and the alkyl ester is preferably dimethyl ester or diethyl ester. In addition to the above components, a small amount of a trifunctional alcohol, tricarboxylic acid or ester thereof may be copolymerized, and an aliphatic dicarboxylic acid such as adipic acid or a dialkyl ester thereof may be used as a copolymerization component.

Examples of the polyalkylene ether glycol include polyethylene glycol, poly (1,2- and / or 1,3-propylene ether) glycol, poly (tetramethylene ether) glycol, poly (hexamethylene ether) glycol, and the like. .

The preferable lower limit of the number average molecular weight of the polyalkylene ether glycol is 400, and the preferable upper limit is 6000. By setting it to 400 or more, the block property of the copolymer becomes high, and by setting it to 6000 or less, phase separation in the system hardly occurs and polymer physical properties are easily developed. A more preferred lower limit is 500, a more preferred upper limit is 4000, a still more preferred lower limit is 600, and a still more preferred upper limit is 3000. In addition, in this specification, a number average molecular weight means what was measured by gel permeation chromatography (GPC). The GPC calibration can be performed, for example, by using a POLYTETRAHYDROFURAN calibration kit (manufactured by POLYMER LABORATORIES, UK).

The polyester elastomer may coexist with a rubber component such as natural rubber and synthetic rubber (for example, polyisoprene rubber) and a softening agent such as process oil. By making the softener coexist, the plasticization of the rubber component can be promoted and the fluidity of the resulting thermoplastic resin composition can be improved. The softening agent may be paraffinic, naphthenic, or aromatic. Moreover, in the range which does not impair the effect of this invention, you may add other components, such as resin other than the above, rubber | gum, a filler, an additive, to this resin component and rubber component.

Examples of the filler include calcium carbonate, talc, silica, kaolin, clay, diatomaceous earth, calcium silicate, mica, asbestos, alumina, barium sulfate, aluminum sulfate, calcium sulfate, magnesium carbonate, carbon fiber, glass fiber, and glass bulb. , Molybdenum sulfide, graphite, shirasu balloon and the like. Examples of the additive include a heat resistance stabilizer, a weather resistance stabilizer, a colorant, an antistatic agent, a flame retardant, a nucleating agent, a lubricant, a slip agent, and an antiblocking agent.

As said heat stabilizer, well-known things, such as a phenol type, a phosphorus type, and a sulfur type, can be used, for example. As the weather resistance stabilizer, known ones such as hindered amines and triazoles can be used. Examples of the colorant include carbon black, titanium white, zinc white, red pepper, azo compound, nitroso compound, and phthalocyanine compound. In addition, known antistatic agents, flame retardants, nucleating agents, lubricants, slip agents, antiblocking agents and the like can be used.

Examples of commercially available polyester elastomers include “Primalloy” (manufactured by Mitsubishi Chemical Corporation), “Perprene” (manufactured by Toyobo Co., Ltd.), “Hytrel” (manufactured by Toray DuPont) and the like.

When using a polyester polyether block copolymer composed of polyester and polyalkylene ether glycol as the polyester elastomer, the content of the polyalkylene ether glycol component is preferably 5% by weight, and preferably 90% by weight. is there. When it is 5% by weight or more, it is excellent in flexibility and impact resistance, and when it is 90% by weight or less, it is excellent in hardness and mechanical strength. A more preferred lower limit is 30% by weight, a more preferred upper limit is 80% by weight, and a still more preferred lower limit is 55% by weight. The content of the polyalkylene ether glycol component can be calculated based on the chemical shift of the hydrogen atom and its content using nuclear magnetic resonance spectroscopy (NMR).

The modified polyester elastomer (hereinafter also referred to as a modified polyester elastomer) is obtained by modifying the polyester elastomer using a modifier. The modification reaction for obtaining the modified polyester elastomer is performed, for example, by reacting the polyester elastomer with an α, β-ethylenically unsaturated carboxylic acid as a modifier. In the modification reaction, a radical generator is preferably used. In the modification reaction, a graft reaction in which an α, β-ethylenically unsaturated carboxylic acid or a derivative thereof is added to a polyester elastomer mainly occurs, but a decomposition reaction also occurs. As a result, the modified polyester elastomer has a lower molecular weight and a lower melt viscosity. Further, in the modification reaction, it is generally considered that a transesterification reaction or the like occurs as another reaction, and the obtained reaction product is generally a composition containing unreacted raw materials, etc. The preferable lower limit of the content of the modified polyester elastomer in the obtained reaction product is 10% by weight, the more preferable lower limit is 30% by weight, and the content of the modified polyester elastomer is more preferably 100% by weight.

Examples of the α, β-ethylenically unsaturated carboxylic acid include unsaturated carboxylic acids such as acrylic acid, maleic acid, fumaric acid, tetrahydrofumaric acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid; succinic acid 2 -Octen-1-yl anhydride, 2-dodecen-1-yl anhydride, succinic acid 2-octadecen-1-yl anhydride, maleic anhydride, 2,3-dimethylmaleic anhydride, bromomalein Acid anhydride, dichloromaleic acid anhydride, citraconic acid anhydride, itaconic acid anhydride, 1-butene-3,4-dicarboxylic acid anhydride, 1-cyclopentene-1,2-dicarboxylic acid anhydride, 1,2, 3,6-tetrahydrophthalic anhydride, 3,4,5,6-tetrahydrophthalic anhydride, exo-3,6-epoxy-1,2,3,6-tetra Hydrophthalic anhydride, 5-norbornene-2,3-dicarboxylic anhydride, methyl-5-norbornene-2,3-dicarboxylic anhydride, endo-bicyclo [2.2.2] oct-5-ene-2 , 3-dicarboxylic acid anhydride, and unsaturated carboxylic acid anhydrides such as bicyclo [2.2.2] oct-7-ene-2,3,5,6-tetracarboxylic acid anhydride. Of these, acid anhydrides are preferred because of their high reactivity. The α, β-ethylenically unsaturated carboxylic acid can be appropriately selected according to the copolymer containing the polyalkylene ether glycol segment to be modified and the modification conditions. Good. The α, β-ethylenically unsaturated carboxylic acid can be used by dissolving in an organic solvent or the like.

Examples of the radical generator include t-butyl hydroperoxide, cumene hydroperoxide, 2,5-dimethylhexane-2,5-dihydroperoxide, 2,5-dimethyl-2,5-bis ( Tertiary butyloxy) hexane, 3,5,5-trimethylhexanoyl peroxide, t-butylperoxybenzoate, benzoyl peroxide, dicumyl peroxide, 1,3-bis (t-butylperoxyisopropyl) benzene Organic and inorganic peroxides such as dibutyl peroxide, methyl ethyl ketone peroxide, potassium peroxide, hydrogen peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (isobutylamide) dihalide, 2,2'-azobis [2-methyl-N- (2-hydrido Kishiechiru) propionamide], azo compounds such as azodi -t- butane, carbon radical generating agents such as dicumyl like. The radical generator can be appropriately selected according to the type of polyester elastomer used for the modification reaction, the type of α, β-ethylenically unsaturated carboxylic acid and the modification conditions, and two or more types can be used in combination. May be. Furthermore, the radical generator can be used by dissolving in an organic solvent or the like.

A preferable lower limit of the amount of the α, β-ethylenically unsaturated carboxylic acid is 0.01 parts by weight with respect to 100 parts by weight of the polyester elastomer, and a preferable upper limit is 30.0 parts by weight. When the amount is 0.01 parts by weight or more, the modification reaction can be sufficiently performed, and when the amount is 30.0 parts by weight or less, it is economically advantageous. A more preferred lower limit is 0.05 parts by weight, a more preferred upper limit is 5.0 parts by weight, a still more preferred lower limit is 0.10 parts by weight, and a still more preferred upper limit is 1.0 part by weight.

A preferable lower limit of the blending amount of the radical generator is 0.001 part by weight with respect to 100 parts by weight of the polyester elastomer, and a preferable upper limit is 3.00 part by weight. When the amount is 0.001 part by weight or more, the modification reaction is likely to occur, and when the amount is 3.00 part by weight or less, the material strength is less likely to decrease due to low molecular weight (decrease in viscosity) during modification. A more preferred lower limit is 0.005 parts by weight, a more preferred upper limit is 0.50 parts by weight, a still more preferred lower limit is 0.010 parts by weight, a still more preferred upper limit is 0.20 parts by weight, and a particularly preferred upper limit is 0.10 parts by weight. Part.

As the modification reaction for obtaining the modified polyester-based elastomer, known reaction methods such as a melt-kneading reaction method, a solution reaction method, a suspension-dispersion reaction can be used. Reaction methods are preferred.

In the method using the melt kneading reaction method, the above-described components are uniformly mixed at a predetermined blending ratio, and then melt kneaded. Henschel mixer, ribbon blender, V-type blender, etc. can be used for mixing each component, and Banbury mixer, kneader, roll, uniaxial or biaxial multi-screw kneading extruder etc. are used for melt-kneading. can do.

The preferable lower limit of the kneading temperature when the melt kneading is performed is 100 ° C., and the preferable upper limit is 300 ° C. By setting it within the above range, thermal deterioration of the resin can be prevented. A more preferred lower limit is 120 ° C., a more preferred upper limit is 280 ° C., a still more preferred lower limit is 150 ° C., and a still more preferred upper limit is 250 ° C.

The preferable lower limit of the modification rate (graft amount) of the modified polyester elastomer is 0.01% by weight, and the preferable upper limit is 10.0% by weight. When the content is 0.01% by weight or more, the affinity with the polyester is increased, and when the content is 10.0% by weight or less, a decrease in strength due to molecular deterioration during modification can be reduced. A more preferred lower limit is 0.03% by weight, a more preferred upper limit is 7.0% by weight, a still more preferred lower limit is 0.05% by weight, and a still more preferred upper limit is 5.0% by weight.

The modification rate (graft amount) of the modified polyester elastomer can be determined from the spectrum obtained by H ¹ -NMR measurement according to the following formula (2). As the equipment used to the ^H 1 -NMR measurement, for example, it can be used to "GSX-400" (manufactured by Nippon Denshi) and the like.

Graft amount (% by weight) = 100 × [(C ÷ 3 × 98) / {(A × 148 ÷ 4) + (B × 72 ÷ 4) + (C ÷ 3 × 98)}] (2)
In the formula (2), A represents an integral value at 7.8 to 8.4 ppm, B represents an integral value at 1.2 to 2.2 ppm, and C represents an integral value at 2.4 to 2.9 ppm.

The preferable lower limit of the JIS-D hardness of the reaction product containing the modified polyester elastomer obtained by the modification reaction is 10, and the preferable upper limit is 80. By setting it to 10 or more, the mechanical strength is improved, and by setting it to 80 or less, flexibility and impact resistance are improved. A more preferred lower limit is 15, a more preferred upper limit is 70, a still more preferred lower limit is 20, and a still more preferred upper limit is 60. The JIS-D hardness can be measured by using a durometer type D by a method in accordance with JIS K 6253.

The preferable lower limit of the total thickness of the heat-shrinkable multilayer film of the present invention is 20 μm, and the preferable upper limit is 80 μm. If the thickness is less than 20 μm, the rigidity and wear resistance required for the heat-shrinkable multilayer film cannot be obtained, and if it exceeds 80 μm, heat is not easily transmitted and the shrink finish may be deteriorated. A more preferred lower limit is 25 μm, a more preferred upper limit is 70 μm, a still more preferred upper limit is 60 μm, and a particularly preferred upper limit is 50 μm.

In the present invention, when the thicknesses of the outer surface layer on the front side and the back side are the same, the ratio of the thickness of the outer surface layer to the intermediate layer (the thickness of the outer surface layer: the thickness of the intermediate layer) is 1: 15-5: It is preferable to be within the range of 1. If the thickness of the intermediate layer is larger than 1:15, the physical properties necessary for the heat shrinkable multilayer film such as solvent resistance and rigidity may not be obtained, and the thickness of the intermediate layer is smaller than 5: 1. And shrinkage | contraction behavior becomes close to a polyester-type resin independent film, and shrinkage finishing property falls. The ratio is more preferably 1:12 to 3: 1, still more preferably 1:10 to 1: 1, and particularly preferably 1: 9 to 1: 3.

When the thickness of the whole film is 45 μm, the preferable lower limit of the thickness of the intermediate layer is 22 μm, and the preferable upper limit is 37 μm. If the thickness is less than 22 μm, sufficient cut performance at the perforation may not be obtained, and if it exceeds 37 μm, sufficient heat resistance may not be obtained. A more preferred lower limit is 26 μm, and a more preferred upper limit is 36 μm.
The preferable lower limit of the thickness of the outer surface layer is 3 μm, and the preferable upper limit is 10 μm. If it is less than 3 μm, sufficient oil resistance and heat resistance may not be obtained, and if it exceeds 10 μm, sufficient cut performance at the perforation may not be obtained. A more preferable lower limit is 4 μm, and a more preferable upper limit is 8 μm.
The preferable lower limit of the thickness of the adhesive layer is 0.5 μm, and the preferable upper limit is 4 μm. If it is less than 0.5 μm, sufficient adhesive strength may not be obtained, and if it exceeds 4 μm, the heat shrinkage characteristics may be deteriorated.

Regarding the heat shrink property of the heat-shrinkable multilayer film of the present invention, the preferred lower limit of the shrinkage when immersed in warm water at 70 ° C. for 10 seconds is 5%, and the preferred upper limit is 60%. If it is less than 5%, a large amount of heat is required at the time of mounting, which may lead to deformation of the container. If it exceeds 60%, it rapidly contracts due to heating, so that wrinkles and the like are likely to occur. A more preferred lower limit is 10%, a more preferred upper limit is 55%, a still more preferred lower limit is 20%, a still more preferred upper limit is 50%, a particularly preferred lower limit is 25%, and a particularly preferred upper limit is 45%.
The shrinkage when immersed in warm water at 70 ° C. for 10 seconds means that the heat-shrinkable multilayer film is cut to have a length of 300 mm and a width of 25 mm so that the main shrinkage direction is the length direction. Then, after immersing a measurement sample with a marked line so that the distance between marked lines becomes 200 mm in 70 ° C. warm water for 10 seconds, measure the distance between marked lines, and after heating to the dimension before the heat treatment It is a value expressed as a percentage of dimensions.

The preferred lower limit of the shrinkage when the heat shrinkable multilayer film of the present invention is allowed to stand for 10 seconds under hot air at 80 ° C. is 5%, and the preferred upper limit is 65%. If it is less than 5%, a large amount of heat is required at the time of mounting, which may lead to deformation of the container. If it exceeds 65%, it rapidly contracts due to heating, so that wrinkles and the like are likely to occur. A more preferred lower limit is 10%, a more preferred upper limit is 60%, a still more preferred lower limit is 20%, a still more preferred upper limit is 55%, a particularly preferred lower limit is 25%, and a particularly preferred upper limit is 50%.
The shrinkage rate when left for 10 seconds under hot air at 80 ° C. means that the heat-shrinkable multilayer film is cut to have a length of 300 mm and a width of 25 mm so that the main shrinkage direction is the length direction. Then, after leaving the measurement sample with the marked line so that the distance between the marked lines becomes 200 mm under hot air at 80 ° C. for 10 seconds, the distance between the marked lines is measured, and after heating to the dimension before the heat treatment It is a value expressed as a percentage of dimensions.

The method for producing the heat-shrinkable multilayer film of the present invention is not particularly limited, but a method of simultaneously forming each layer by a coextrusion method is suitable. For example, in co-extrusion using a T-die, any of a feed block method, a multi-manifold method, or a method using these in combination may be used as a lamination method. Specifically, for example, a polyester resin as the resin constituting the outer surface layer, a polystyrene resin as the resin constituting the intermediate layer, and a modified polyester elastomer as the resin constituting the adhesive layer are put into the extruder, respectively, and the multilayer die is used. A method of extruding into a sheet shape, cooling and solidifying with a take-off roll, and stretching uniaxially or biaxially can be used. The stretching temperature needs to be changed depending on the softening temperature of the resin constituting the film and the shrinkage characteristics required for the heat-shrinkable multilayer film. The preferred lower limit of the stretching temperature is 75 ° C., the preferred upper limit is 120 ° C., and more preferred. The lower limit is 80 ° C, and the more preferable upper limit is 115 ° C.

A heat-shrinkable label can be obtained by using the heat-shrinkable multilayer film of the present invention as a base film. Such a heat-shrinkable label is also one aspect of the present invention.
In the heat-shrinkable label of the present invention, the heat-shrinkable multilayer film may be used as a base film, and other layers such as a printing layer may be laminated as necessary.

As a method of attaching the heat-shrinkable label to the container, usually, a solvent is used to bond between the ends of the heat-shrinkable multilayer film to form a tube (center seal processing) to obtain a heat-shrinkable label. A method is employed in which the container is heated and shrunk while the container is covered.

According to the present invention, when used as a heat-shrinkable label for dry heat shrinkage, excellent shrink finish is realized without occurrence of defects such as wrinkles, printed pattern distortion, shrinkage unevenness, etc. after mounting. The heat-shrinkable multilayer film and the heat-shrinkable label using the heat-shrinkable multilayer film as a base film can be provided.

Hereinafter, the present invention will be described in more detail with reference to examples. However, the present invention is not limited to these examples.

(Example 1)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
These resins were put into an extruder having a barrel temperature of 160 to 250 ° C., extruded from a multilayer die at 250 ° C. into a sheet having a three-layer structure, and cooled and solidified by a take-up roll at 30 ° C. Next, the film was stretched at a stretching ratio of 6 in a tenter stretching machine having a preheating zone of 110 ° C., a stretching zone of 90 ° C., and a heat setting zone of 70 ° C., and then wound up with a winder to obtain a heat-shrinkable multilayer film.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (6 μm) / adhesive layer (1 μm) / intermediate layer (26 μm) / adhesive layer (1 μm) / outer surface layer (6 μm). It consisted of.
The Vicat softening temperature was measured by a method according to JIS K 7206 (1999). After a test piece was collected from the resin, a load of 10 N was applied to the needle-shaped indenter placed on the test piece, The temperature was measured by increasing the temperature at a speed and checking the temperature when the needle-like indenter entered 1 mm.

(Example 2)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
As a resin constituting the adhesive layer, a polyester-based elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Example 3)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

Example 4
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
As the resin constituting the adhesive layer, a styrene-isoprene copolymer (Clayton D1124, manufactured by Kraton Co., Ltd.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (7 μm) / adhesive layer (1 μm) / intermediate layer (24 μm) / adhesive layer (1 μm) / outer surface layer (7 μm). It consisted of.

(Example 5)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (7 μm) / intermediate layer (26 μm) / outer surface layer (7 μm).

(Example 6)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (15 μm) / intermediate layer (10 μm) / outer surface layer (15 μm).

(Example 7)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (13 μm) / adhesive layer (1 μm) / intermediate layer (12 μm) / adhesive layer (1 μm) / outer surface layer (13 μm). It consisted of.

(Example 8)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

Example 9
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 82% by weight, butadiene 17% by weight, isoprene 1% by weight: Vicat softening temperature 69 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

(Example 10)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (81% by weight of styrene, 18% by weight of butadiene, 1% by weight of isoprene: Vicat softening temperature 76 ° C.) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

Example 11
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (81% by weight of styrene, 18% by weight of butadiene, 1% by weight of isoprene: Vicat softening temperature 76 ° C.) was used.
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

Example 12
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 83 wt%, butadiene 17 wt%: Vicat softening temperature 80 ° C.) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

(Example 13)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 83 wt%, butadiene 17 wt%: Vicat softening temperature 80 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (10 μm) / intermediate layer (20 μm) / outer surface layer (10 μm).

(Example 14)
The resin constituting the outer surface layer contains 98.5 mol% of a component derived from terephthalic acid as a dicarboxylic acid component, 1.5 mol% of a component derived from isophthalic acid, and 72 components derived from ethylene glycol as a diol component. A polyester resin (Vicat softening temperature 70 ° C.) containing 20 mol% of a component derived from mol%, 2n-butyl-2-ethyl-1,3-propanediol and 8 mol% of a component derived from diethylene glycol was used. .
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 73 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

(Example 15)
The resin constituting the outer surface layer contains 98.5 mol% of a component derived from terephthalic acid as a dicarboxylic acid component, 1.5 mol% of a component derived from isophthalic acid, and 72 components derived from ethylene glycol as a diol component. A polyester resin (Vicat softening temperature 70 ° C.) containing 20 mol% of a component derived from mol%, 2n-butyl-2-ethyl-1,3-propanediol and 8 mol% of a component derived from diethylene glycol was used. .
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 79% by weight, butadiene 21% by weight: Vicat softening temperature 70 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (10 μm) / intermediate layer (20 μm) / outer surface layer (10 μm).

(Example 16)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 79% by weight, butadiene 21% by weight: Vicat softening temperature 70 ° C.) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

(Example 17)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a resin (Vicat softening temperature) obtained by mixing 80 parts by weight of styrene-butadiene copolymer (75% by weight of styrene, 25% by weight of butadiene: 83 ° C. Vicat softening temperature) and 20 parts by weight of GPPS. 90 ° C.).
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

(Example 18)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a resin obtained by mixing 80 parts by weight of styrene-butadiene copolymer (80% by weight of styrene, 20% by weight of butadiene: Vicat softening temperature 87 ° C.) and 20 parts by weight of GPPS was used.
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

Example 19
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 84 wt%, butadiene 16 wt%: Vicat softening temperature 83 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (10 μm) / intermediate layer (20 μm) / outer surface layer (10 μm).

(Example 20)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As components constituting the intermediate layer, 60 parts by weight of a styrene-butyl acrylate copolymer (83% by weight of styrene, 17% by weight of butyl acrylate) and 40% by weight of a styrene-butadiene copolymer (65% by weight of styrene, 35% by weight of butadiene) The mixture (Vicat softening temperature 76 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

(Example 21)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As components constituting the intermediate layer, 60 parts by weight of a styrene-butyl acrylate copolymer (80% by weight of styrene, 20% by weight of butyl acrylate) and 40 parts of a styrene-butadiene copolymer (65% by weight of styrene, 35% by weight of butadiene) What mixed the weight part (Vicat softening temperature 74 degreeC) was used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (10 μm) / intermediate layer (20 μm) / outer surface layer (10 μm).

(Example 22)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C., MFR 7.0 g / 10 min) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 30 μm, and is composed of five layers: outer surface layer (3 μm) / adhesive layer (1 μm) / intermediate layer (22 μm) / adhesive layer (1 μm) / outer surface layer (3 μm). It consisted of.

(Comparative Example 1)
As a resin constituting the outer surface layer, a polyester system containing terephthalic acid as a dicarboxylic acid component, 67 mol% of a component derived from ethylene glycol as a diol component, and 33 mol% of a component derived from 1,4-cyclohexanedimethanol Resin (Vicat softening temperature 85 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 78% by weight, butadiene 22% by weight: Vicat softening temperature 72 ° C., MFR 5.6 g / 10 min) was used.
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (7 μm) / adhesive layer (1 μm) / intermediate layer (29 μm) / adhesive layer (1 μm) / outer surface layer (7 μm). It consisted of.

(Comparative Example 2)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (80% by weight of styrene, 19% by weight of butadiene, 1% by weight of isoprene: Vicat softening temperature 66 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 3)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (82% by weight of styrene, 17% by weight of butadiene, 1% by weight of isoprene: Vicat softening temperature 66 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (4 μm) / intermediate layer (32 μm) / outer surface layer (4 μm).

(Comparative Example 4)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (82% by weight of styrene, 17% by weight of butadiene, 1% by weight of isoprene: Vicat softening temperature 66 ° C.) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (3 μm) / adhesive layer (1 μm) / intermediate layer (32 μm) / adhesive layer (1 μm) / outer surface layer (3 μm). It consisted of.

(Comparative Example 5)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (82% by weight of styrene, 17% by weight of butadiene, 1% by weight of isoprene: Vicat softening temperature 66 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (7 μm) / intermediate layer (31 μm) / outer surface layer (7 μm).

(Comparative Example 6)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 82% by weight, butadiene 17% by weight, isoprene 1% by weight: Vicat softening temperature 69 ° C.) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 45 μm, and is composed of five layers: outer surface layer (5 μm) / adhesive layer (1 μm) / intermediate layer (33 μm) / adhesive layer (1 μm) / outer surface layer (5 μm). It consisted of.

(Comparative Example 7)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 82% by weight, butadiene 17% by weight, isoprene 1% by weight: Vicat softening temperature 69 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 8)
As a resin constituting the outer surface layer, a polyester system containing terephthalic acid as a dicarboxylic acid component, 67 mol% of a component derived from ethylene glycol as a diol component, and 33 mol% of a component derived from 1,4-cyclohexanedimethanol Resin (Vicat softening temperature 85 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 83 wt%, butadiene 17 wt%: Vicat softening temperature 80 ° C.) was used.
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 9)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, 70 mol% of the component derived from ethylene glycol is used as the diol component, 25 mol% of the component derived from 1,4-cyclohexanedimethanol is derived from diethylene glycol A polyester resin (Vicat softening temperature 80 ° C.) containing 5 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 77% by weight, butadiene 22% by weight, isoprene 1% by weight: Vicat softening temperature 68 ° C.) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film had a total thickness of 40 μm and consisted of a three-layer structure of outer surface layer (4 μm) / intermediate layer (32 μm) / outer surface layer (4 μm).

(Comparative Example 10)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, 70 mol% of the component derived from ethylene glycol is used as the diol component, 25 mol% of the component derived from 1,4-cyclohexanedimethanol is derived from diethylene glycol A polyester resin (Vicat softening temperature 80 ° C.) containing 5 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 78% by weight, butadiene 21% by weight, isoprene 1% by weight: Vicat softening temperature 72 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 11)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, 70 mol% of the component derived from ethylene glycol is used as the diol component, 25 mol% of the component derived from 1,4-cyclohexanedimethanol is derived from diethylene glycol A polyester resin (Vicat softening temperature 80 ° C.) containing 5 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 79% by weight, butadiene 20% by weight, isoprene 1% by weight: Vicat softening temperature 71 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 12)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 78% by weight, butadiene 21% by weight, isoprene 1% by weight: Vicat softening temperature 66 ° C.) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 13)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, 70 mol% of the component derived from ethylene glycol is used as the diol component, 27 mol% of the component derived from 1,4-cyclohexanedimethanol is derived from diethylene glycol A polyester resin (Vicat softening temperature 82 ° C.) containing 3 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 77 wt%, butadiene 22 wt%, isoprene 1 wt%: Vicat softening temperature 66 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 14)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, 70 mol% of the component derived from ethylene glycol is used as the diol component, 23 mol% of the component derived from 1,4-cyclohexanedimethanol is derived from diethylene glycol A polyester resin (Vicat softening temperature 77 ° C.) containing 7 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 77 wt%, butadiene 22 wt%, isoprene 1 wt%: Vicat softening temperature 66 ° C.) was used.
As a resin constituting the adhesive layer, maleic anhydride-modified styrene-ethylene / butylene-styrene block copolymer (styrene content 30% by weight, maleic anhydride addition amount 1.0% by weight, MFR 4.0 g / 10 min, specific gravity 0 .92) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 15)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, 70 mol% of the component derived from ethylene glycol is used as the diol component, 25 mol% of the component derived from 1,4-cyclohexanedimethanol is derived from diethylene glycol A polyester resin (Vicat softening temperature 80 ° C.) containing 5 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 74 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 16)
As the resin constituting the outer layer, terephthalic acid is used as the dicarboxylic acid component, the component derived from ethylene glycol as the diol component is 70 mol%, the component derived from 1,4-cyclohexanedimethanol is derived from 20 mol%, and derived from diethylene glycol A polyester resin (Vicat softening temperature 74 ° C.) containing 10 mol% of the component to be used was used.
As a component constituting the intermediate layer, a styrene-butadiene copolymer (styrene 77 wt%, butadiene 23 wt%: Vicat softening temperature 73 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 17)
As a resin constituting the outer surface layer, a polyester system containing terephthalic acid as a dicarboxylic acid component, 67 mol% of a component derived from ethylene glycol as a diol component, and 33 mol% of a component derived from 1,4-cyclohexanedimethanol Resin (Vicat softening temperature 85 ° C.) was used.
As components constituting the intermediate layer, 60 parts by weight of styrene-butyl acrylate copolymer (80% by weight of styrene, 20% by weight of butyl acrylate) and 40% by weight of styrene-butadiene copolymer (65% by weight of styrene, 35% by weight of butadiene) A mixture with the part (Vicat softening temperature 74 ° C.) was used.
As the resin constituting the adhesive layer, a modified polyester elastomer (Mitsubishi Chemical Corporation, Primalloy APIF203, melting point 180 ° C., MFR 30.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (4 μm) / adhesive layer (1 μm) / intermediate layer (30 μm) / adhesive layer (1 μm) / outer surface layer (4 μm). It consisted of.

(Comparative Example 18)
As a resin constituting the outer surface layer, a polyester resin (Eastman Chemical Co., EMBRACE LV, Vicat softening temperature 69 ° C.) was used.
As a component constituting the intermediate layer, a styrene-butadiene-isoprene copolymer (styrene 78% by weight, butadiene 21% by weight, isoprene 1% by weight: Vicat softening temperature 67 ° C.) was used.
As a resin constituting the adhesive layer, a polyester elastomer (manufactured by Mitsubishi Chemical Corporation, Primalloy A1600N, melting point 160 ° C., MFR 5.0 g / 10 min) was used.
A heat-shrinkable multilayer film was obtained in the same manner as in Example 1 except that these resins were used.
The obtained heat-shrinkable multilayer film has a total thickness of 40 μm and is composed of five layers: outer surface layer (10 μm) / adhesive layer (1 μm) / intermediate layer (18 μm) / adhesive layer (1 μm) / outer surface layer (10 μm). It consisted of.

(Evaluation)
(1) Dry heat shrinkage ratio measurement The obtained heat-shrinkable multilayer film was cut so that the length of the main shrinkage was 300 mm and the width of 25 mm, and the distance between marked lines was 200 mm. A marked line was drawn to make a measurement sample (see FIG. 1). Next, both ends of the measurement sample are fixed to an indicator bar having a length of 520 mm, the heat-shrinkable multilayer film of the fixing part is bent outward (see FIG. 2), and the temperature is set to 70 ° C. and the humidity is set to 20%. It poured from the side hole of the tank (Nagano Scientific Machinery Co., Ltd., LH31-12M). The heat-shrinkable multilayer film is taken out 10 seconds after the introduction, the distance between the marked lines is measured, and the shrinkage ratio between the marked lines ((200 mm−distance between marked lines after shrinking (mm) / 200 mm) × 100) is calculated. did. The shrinkage rate was n = 3 and the average value was used. In addition, a value 2% or more away from the average value is not counted.
The measurement was also performed when the constant temperature and humidity chamber was set to 80 ° C.

(2) Wet heat shrinkage ratio measurement About the obtained heat-shrinkable multilayer film, (1) Similarly to the case of dry heat shrinkage ratio measurement, after the measurement sample of FIG. Except that it was immersed for 10 seconds, the wet heat shrinkage was measured in the same manner as (1) dry heat shrinkage measurement.

(3) Shrinkage finishing property After drawing lines at 5 mm intervals in the direction perpendicular to and parallel to the main shrinkage axis direction of the obtained heat-shrinkable multilayer film, and describing a 5 mm × 5 mm grid, the folding diameter is 129 mm A heat-shrinkable label having a pitch of 105 mm was produced.
This heat-shrinkable label is placed on a white polypropylene cup (upper diameter: 188 mm, lower diameter: 253 mm, height: 99 mm, weight: 13 g), and the lower four places are attached with an adhesive tape, and then tunnel (Nippon Technology Solution Co., Ltd.) Made by Pure-2001 2500 type) and contracted under the following tunnel conditions. And the shrinkage | contraction state of the heat-shrinkable label was observed visually, and shrinkage finishing property and external appearance were evaluated by the following references | standards.
◯: Generation of non-shrinking wrinkles, biting wrinkles, longitudinal distortion, oblique distortion, and shrinkage unevenness were not observed.
×: Even with one piece, generation of non-shrinking wrinkles, biting wrinkles, longitudinal distortion, oblique distortion, and shrinkage unevenness was observed.

(Tunnel conditions)
Preheating first zone: set temperature 80 ° C, fan output 60Hz
Preheating second zone: set temperature 115 ° C, fan output 50Hz
Heating zone: set temperature 150 ° C, fan output 20Hz
Tunnel transit time: 20 seconds

As shown in Table 1, it can be seen that all of the heat-shrinkable multilayer films obtained in the examples have high shrink finish. As an example, FIG. 3 shows a photograph of the state after mounting the heat-shrinkable multilayer film obtained in Example 2 on a container. Heat shrinkable multilayer film obtained in Comparative Example while no shrinkage wrinkles, biting wrinkles, longitudinal strain, oblique strain, shrinkage unevenness was observed and it was found that it had excellent shrink finish It can be seen that the shrinkage finish is low. As an example, FIG. 4 shows a photograph of the state after mounting the heat-shrinkable multilayer film obtained in Comparative Example 1 on a container. In this case, it can be seen that non-shrinkage wrinkles and biting wrinkles are generated. Moreover, the photograph which image | photographed the state after mounting | wearing the container with the heat-shrinkable multilayer film obtained by the comparative example 12 is shown in FIG. In this case, it can be seen that shrinkage unevenness and distortion in the vertical direction and the oblique direction are generated.

According to the present invention, when used as a heat-shrinkable label for dry heat shrinkage, excellent shrink finish is realized without occurrence of defects such as wrinkles, printed pattern distortion, shrinkage unevenness, etc. after mounting. The heat-shrinkable multilayer film and the heat-shrinkable label using the heat-shrinkable multilayer film as a base film can be provided.

It is a schematic diagram which shows the measurement sample in dry heat shrinkage rate measurement and wet heat shrinkage rate measurement. It is a schematic diagram which shows the measuring method of dry heat shrinkage rate measurement and wet heat shrinkage rate measurement. It is the photograph which image | photographed the state after mounting | wearing with the heat-shrinkable multilayer film obtained in Example 2. FIG. It is the photograph which image | photographed the state after mounting | wearing with the heat-shrinkable multilayer film obtained by the comparative example 1. It is the photograph which image | photographed the state after mounting | wearing with the heat-shrinkable multilayer film obtained by the comparative example 12.

Claims (5)

An outer surface layer containing a polyester resin is a heat-shrinkable multilayer film laminated via an intermediate layer containing a polystyrene resin,
The heat-shrinkable multilayer film, wherein the Vicat softening temperature (Vt1) of the polyester resin and the Vicat softening temperature (Vt2) of the polystyrene resin satisfy the following formula (1).

The heat-shrinkable multilayer film according to claim 1, wherein the Vicat softening temperature (Vt1) of the polyester resin is 60 to 80 ° C. The heat-shrinkable multilayer film according to claim 1 or 2, further comprising an adhesive layer between the outer surface layer and the intermediate layer. The heat-shrinkable multilayer film according to claim 3, wherein the resin constituting the adhesive layer is a styrene-based elastomer, a polyester-based elastomer, or a modified product thereof. A heat-shrinkable label comprising the heat-shrinkable multilayer film according to claim 1, 2, 3 or 4.

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