JP2006104237A - Heat-shrinkable film comprising alicyclic structure-containing polymer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heat-shrinkable film excellent both in resistance to whitening with finger sebum and in surface gloss. <P>SOLUTION: The heat-shrinkable film has at least one layer prepared by stretching a film comprising a resin composition (C) comprising an alicyclic structure containing polymer (A) and an aromatic vinyl/conjugated diene block copolymer (B) having an aromatic vinyl block content of 10 to 30 wt.% in an (A)/(B) weight ratio in the range of 85/15 to 70/30. It is preferable that the aromatic vinyl/conjugated diene block copolymer (B) is a styrene/isoprene block copolymer. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heat-shrinkable film comprising an alicyclic structure-containing polymer, and more specifically, a ratio of an alicyclic structure-containing polymer and an aromatic vinyl block that is excellent in finger whitening resistance and surface gloss. The present invention relates to a heat-shrinkable film comprising a resin composition containing an aromatic vinyl / conjugated diene block copolymer having a content of 10 to 30% by weight.

A heat-shrinkable film made of a resin composition containing an alicyclic structure-containing polymer is excellent in heat-shrinkability and transparency, and is used as a packaging material for PET bottles and the like.
In addition, in order to improve the strength of the heat-shrinkable film, it has been studied to add a soft polymer to the alicyclic structure-containing polymer.
Patent Document 1 discloses a heat-shrinkable film obtained by stretching a film comprising a resin composition in which 100 parts by weight of an alicyclic structure-containing polymer is blended with 18 parts by weight of an ethylene / propylene random copolymer as a soft polymer. Is disclosed.
Patent Document 2 contains 100 parts by weight of an alicyclic structure-containing polymer and 20 parts by weight of a hydride of a styrene / butadiene / styrene block copolymer having a ratio of 42% by weight of an aromatic vinyl block as a soft polymer. A heat-shrinkable film obtained by stretching a film made of the resin composition is disclosed.
JP-A-8-165357 JP 2000-143829 A

On the other hand, in the field of packaging materials such as PET bottles, the surface gloss from the point of view of the design of the product that finger oils do not whiten when touched by hand and then thermally shrink (finger whitening resistance) and the design of the product Sex is required.
However, the heat-shrinkable films described in Patent Documents 1 and 2 do not satisfy both finger whitening resistance and surface gloss.
Therefore, the subject of this invention is providing the heat-shrinkable film excellent in finger-fat whitening resistance and surface glossiness.

As a result of intensive studies to solve the above-mentioned problems, the present inventors have found that an alicyclic structure-containing polymer and an aromatic vinyl / conjugated diene block copolymer in which the ratio of the aromatic vinyl block is 10 to 30% by weight. A heat-shrinkable film having at least one layer formed by stretching a film made of a resin composition formulated with a specific ratio is found to have excellent finger whitening resistance and surface glossiness, completing the present invention. It came to do.
Thus, according to the present invention, the alicyclic structure-containing polymer (A) and the aromatic vinyl block conjugated diene block copolymer (B) having an aromatic vinyl block ratio of 10 to 30% by weight are contained, There is provided a heat-shrinkable film having at least one layer formed by stretching a film made of a resin composition (C) in which (A) / (B) is in the range of 85/15 to 70/30 by weight ratio. .
In addition, the aromatic vinyl / conjugated diene block copolymer (B) is preferably a block copolymer of styrene and isoprene, and the aromatic vinyl / conjugated diene block copolymer (B) is derived from a conjugated diene compound-derived single copolymer. The proportion of monomer units derived from 1,2- and 3,4-addition polymerization in the monomer units is more preferably 60% by weight or more. Moreover, it is especially preferable that the surface glossiness of the heat-shrinkable film is 120 to 150%.

  The heat-shrinkable film of the present invention is excellent in finger fat whitening resistance and surface gloss.

The heat-shrinkable film of the present invention contains an alicyclic structure-containing polymer (A) and an aromatic vinyl / conjugated diene block copolymer (B) in which the ratio of the aromatic vinyl block is 10 to 30% by weight. It has at least one layer formed by stretching a film made of the resin composition (C).
In the present invention, the term “film” refers to a flat-shaped molded body (generally referred to as “film”) having a thickness of 250 μm or less, and a flat-shaped molded body having a thickness of 3 to 250 μm (generally “ Sometimes called a "sheet").

(Alicyclic structure-containing polymer (A))
The alicyclic structure-containing polymer used in the present invention is a polymer containing an alicyclic structure in the repeating unit of the polymer.
The alicyclic structure may be present in either the main chain or the side chain, but from the viewpoint of the mechanical strength and heat resistance of the resulting heat-shrinkable film, the main chain contains the alicyclic structure. Is preferred.
Examples of the alicyclic structure include a cycloalkane structure and a cycloalkene structure, and a cycloalkane structure is preferable from the viewpoint of the thermal stability of the polymer.
The number of carbon atoms constituting the alicyclic structure is usually in the range of 4 to 30, preferably 5 to 20, and more preferably 5 to 15. When the number of carbon atoms constituting the alicyclic structure is within this range, the heat-shrinkable film obtained has excellent heat resistance.
The ratio of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer is not particularly limited, but is preferably 50% by weight or more, more preferably 70% by weight or more, and 90% by weight or more. And particularly preferred. When the ratio of the repeating unit having an alicyclic structure in the alicyclic structure-containing polymer is within this range, the heat resistance of the resulting heat-shrinkable film is excellent.
In addition, the remainder other than the repeating unit which has an alicyclic structure in an alicyclic structure containing polymer is suitably selected according to the intended purpose.

Specific examples of the alicyclic structure-containing polymer include (1) norbornene polymer, (2) monocyclic olefin polymer, (3) cyclic conjugated diene polymer, and (4) vinyl alicyclic hydrocarbon. Examples thereof include polymers and hydrides thereof.
Among these, norbornene-based polymers, cyclic conjugated diene polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof are preferable from the viewpoint of heat resistance, mechanical strength, and the like of the heat-shrinkable film obtained. More preferred are polymer-based polymers, vinyl alicyclic hydrocarbon polymers, and hydrides thereof, and hydrides of norbornene-based polymers are particularly preferable.

(1) Norbornene-based polymer The norbornene-based polymer includes a ring-opening polymer of a norbornene-based monomer, a ring-opening copolymer of a norbornene-based monomer and other monomers capable of ring-opening copolymerization, and hydrides thereof. Addition polymers of norbornene monomers, addition copolymers of norbornene monomers and other monomers that can be addition copolymerized therewith, and the like. Among these, a ring-opening polymer hydride of a norbornene monomer is most preferable from the viewpoints of heat resistance, mechanical strength, and the like of the heat-shrinkable film obtained.

ノルボルネン系モノマーとしては、ビシクロ［２．２．１］ヘプト−２−エン（慣用名：ノルボルネン）及びその誘導体（環に置換基を有するもの）、トリシクロ［４．３．０．１^２，５］デカ−３，７−ジエン（慣用名：ジシクロペンタジエン）及びその誘導体、テトラシクロ［７．４．０．０^２，７．１^{１０，１３}］トリデカ−２，４，６，１１−テトラエン（慣用名：メタノテトラヒドロフルオレン）及びその誘導体、テトラシクロ［４．４．０．１^２，５．１^７，１０］ドデカ−３−エン（慣用名：テトラシクロドデセン）及びその誘導体などが挙げられる。
置換基としては、アルキル基、アルキレン基、ビニル基、アルコキシカルボニル基などが例示でき、上記ノルボルネン系モノマーは、これらの置換基を２種以上有していてもよい。
具体的には、８−メトキシカルボニル−テトラシクロ［４．４．０．１^２，５．１^７，１０］ドデカ−３−エン、８−メチル−８−メトキシカルボニル−テトラシクロ［４．４．０．１^２，５．１^７，１０］ドデカ−３−エンなどが挙げられる。これらのノルボルネン系モノマーは、それぞれ単独であるいは２種以上を組み合わせて用いられる。 In the present invention, the norbornene-based monomer is a compound having a norbornene structure represented by the formula (1).

Examples of the norbornene-based monomer include bicyclo [2.2.1] hept-2-ene (common name: norbornene) and derivatives thereof (having a substituent in the ring), tricyclo [4.3.0.1 ^2,5 ] Deca-3,7-diene (common name: dicyclopentadiene) and derivatives thereof, tetracyclo [7.4.0.0 ^2,7 . 1 ^10,13] trideca -2,4,6,11- tetraene (common name: methanolate tetrahydrofluorene) and derivatives thereof, tetracyclo [4.4.0.1 ^{2, 5. 17, 10} ] dodec-3-ene (common name: tetracyclododecene) and its derivatives.
Examples of the substituent include an alkyl group, an alkylene group, a vinyl group, and an alkoxycarbonyl group, and the norbornene-based monomer may have two or more of these substituents.
Specifically, 8-methoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene, 8-methyl-8-methoxycarbonyl-tetracyclo [4.4.0.1 ^2,5 . 1 ^7,10 ] dodec-3-ene and the like. These norbornene monomers are used alone or in combination of two or more.

Ring-opening polymers of these norbornene monomers, or ring-opening copolymers of norbornene monomers and other monomers capable of ring-opening copolymerization are polymerized in the presence of a known ring-opening polymerization catalyst. Can be obtained.
Ring-opening polymerization catalysts include metal halides such as ruthenium and osmium, nitrates or acetylacetone compounds, and reducing agents; metal halides or acetylacetone compounds such as titanium, zirconium, tungsten and molybdenum, and organoaluminum. And a catalyst comprising a cocatalyst such as a compound.

  Examples of other monomers capable of ring-opening copolymerization with norbornene monomers include monocyclic olefin monomers such as cyclohexene, cycloheptene, and cyclooctene.

  The ring-opening polymer hydride of a norbornene-based monomer is usually prepared by adding a known hydrogenation catalyst containing a transition metal such as nickel or palladium to the polymerization solution of the above-mentioned ring-opening polymer so that the carbon-carbon unsaturated bond is hydrogenated. Can be obtained.

  Addition polymers of norbornene monomers, or addition copolymers of norbornene monomers and other monomers copolymerizable therewith, these monomers can be combined with known addition polymerization catalysts such as titanium, zirconium or vanadium compounds. It can be obtained by (co) polymerization using a catalyst comprising an organoaluminum compound.

  Other monomers that can be copolymerized with norbornene monomers include, for example, ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-octene, 1-decene, 1-dodecene, 1-tetradecene, 1 -C2-C20 alpha-olefins, such as hexadecene, 1-octadecene, 1-eicocene, and derivatives thereof; cyclobutene, cyclopentene, cyclohexene, cyclooctene, 3a, 5,6,7a-tetrahydro-4,7- Cycloolefins such as methano-1H-indene, and derivatives thereof; non-conjugated such as 1,4-hexadiene, 4-methyl-1,4-hexadiene, 5-methyl-1,4-hexadiene, 1,7-octadiene Diene; etc. are used. Among these, an α-olefin, particularly ethylene is preferable.

  These other monomers capable of addition copolymerization with norbornene-based monomers can be used alone or in combination of two or more. In the case of addition copolymerization of a norbornene monomer and another monomer capable of addition copolymerization, a structural unit derived from a norbornene monomer in the addition copolymer and a structural unit derived from another monomer capable of copolymerization are used. The ratio is appropriately selected so that it is usually in the range of 30:70 to 99: 1, preferably 50:50 to 97: 3, more preferably 70:30 to 95: 5 by weight.

(2) Monocyclic Cyclic Olefin Polymer Examples of the monocyclic cycloolefin polymer include addition polymers of monocyclic cycloolefin monomers such as cyclohexene, cycloheptene, and cyclooctene.

(3) Cyclic conjugated diene polymer Examples of the cyclic conjugated diene polymer include polymers obtained by subjecting a cyclic conjugated diene monomer such as cyclopentadiene and cyclohexadiene to 1,2- or 1,4-addition polymerization, and hydrides thereof. .

The weight average molecular weight of the norbornene-based polymer, monocyclic olefin polymer or cyclic conjugated diene polymer is appropriately selected according to the purpose of use of the multilayer film, but is usually 5,000 to 500,000, preferably 8 The range is from 10,000 to 200,000, more preferably from 10,000 to 100,000, and particularly preferably from 20,000 to 60,000. When the weight average molecular weight is in this range, the moldability of the obtained resin composition and the mechanical strength of the obtained heat-shrinkable film are highly balanced, which is preferable.
Here, the weight average molecular weight is a value in terms of polyisoprene or polystyrene measured by a gel permeation chromatography method of a cyclohexane solution (or a toluene solution when the polymer resin is not dissolved).

(4) Vinyl alicyclic hydrocarbon polymer As the vinyl alicyclic hydrocarbon polymer, polymers of vinyl alicyclic hydrocarbon monomers such as vinylcyclohexene and vinylcyclohexane and their hydrides; styrene, α-methylstyrene And other monomers such as butadiene that can be copolymerized with vinyl alicyclic hydrocarbon monomers and vinyl aromatic monomers, and the like. Any of a random copolymer, a copolymer such as a block copolymer, and a hydride thereof may be used. Examples of the block copolymer include diblock, triblock, or more multiblock and gradient block copolymers, and are not particularly limited.

  When the vinyl alicyclic hydrocarbon polymer is a hydride of the aromatic ring portion of the polymer of the vinyl aromatic monomer, the hydrogenation rate of the aromatic ring portion is usually 50% or more, preferably 80% or more, more preferably Is 90% or more, particularly preferably 95% or more, and most preferably 99% or more.

The weight average molecular weight of the vinyl alicyclic hydrocarbon polymer is appropriately selected according to the purpose of use of the multilayer film, but is usually 10,000 to 300,000, preferably 15,000 to 250,000, more preferably. It is in the range of 20,000 to 200,000. When the weight average molecular weight is within this range, the molding processability of the obtained resin composition and the mechanical strength of the resulting multilayer film are highly balanced, which is preferable.
Here, the weight average molecular weight is a value in terms of polyisoprene or polystyrene measured by a gel permeation chromatography method of a cyclohexane solution (or a toluene solution when the polymer resin is not dissolved).

The melt mass flow rate (MFR) of the alicyclic structure-containing polymer used in the present invention is not particularly limited, but is preferably in the range of 2 to 30 g / 10 minutes, and more preferably in the range of 3 to 20 g / 10 minutes. A range of 5 to 10 g / 10 min is particularly preferable. When the MFR is in this range, the moldability of the resulting resin composition is excellent.
In the present invention, melt mass flow rate (MFR) is a value measured according to JIS K 7210 under conditions of a temperature of 230 ° C. and a load of 21.18 N.

The glass transition temperature (Tg) of the alicyclic structure-containing polymer used in the present invention is preferably 50 ° C. or higher, and particularly preferably in the range of 60 ° C. to 90 ° C. When Tg is within this range, the heat-shrinkable film obtained has excellent heat resistance and durability.
In the present invention, Tg is a value measured by differential scanning calorimetry (DSC) based on JIS K7121.

(Aromatic vinyl / conjugated diene block copolymer (B) having an aromatic vinyl block ratio of 10 to 30% by weight)
The aromatic vinyl / conjugated diene block copolymer (B) used in the present invention having an aromatic vinyl block ratio of 10 to 30% by weight is a block copolymer having an aromatic vinyl block and a conjugated diene block. In the block copolymer, the ratio of the aromatic vinyl block in the polymer is in the range of 10 to 30% by weight.
In the present invention, the aromatic vinyl block is a portion obtained by polymerizing an aromatic vinyl compound, and the conjugated diene block is a portion obtained by polymerizing a conjugated diene compound.

  Examples of the conjugated diene compound used here include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-methyl-1,3-pentadiene, 1,3- Examples include hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, and chloroprene. Among these, 1,3-butadiene, isoprene and 1,3-pentadiene are preferable, 1,3-butadiene and isoprene are more preferable, and isoprene is particularly preferable.

  Examples of the aromatic vinyl compound used here include styrene, α-methylstyrene, p-methylstyrene, t-butylstyrene, divinylbenzene, N, N-dimethyl-p-aminoethylstyrene, and N, N-diethyl. -P-aminoethylstyrene, vinylpyridine, etc. are mentioned. Among these, styrene and α-methylstyrene are preferable, and styrene is more preferable.

The ratio of the aromatic vinyl block in the aromatic vinyl / conjugated diene block copolymer (B) is not particularly limited as long as it is in the range of 10 to 30% by weight, but is preferably in the range of 12 to 28% by weight, It is more preferable in the range of 15 to 25% by weight.
The ratio of the aromatic vinyl block can be determined by preparing a calibration curve for absorption based on a phenyl group of 679 cm ⁻¹ by infrared analysis.

  Examples of the block copolymer include diblocks, triblocks, or more multiblocks, and are not particularly limited.

Ratio of monomer units derived from 1,2- and 3,4-addition polymerization in monomer units derived from the conjugated diene compound of the aromatic vinyl / conjugated diene block copolymer (B) used in the present invention. Is not particularly limited, but is preferably 60% by weight or more, more preferably 65% by weight or more, and particularly preferably 69% by weight or more.
The ratio of the monomer units derived from 1,2- and 3,4-addition polymerization in the monomer units derived from the conjugated diene compound of the aromatic vinyl / conjugated diene block copolymer (B) is within this range. And the transparency of the heat-shrinkable film obtained is excellent.

  The monomer unit derived from the conjugated diene compound of the aromatic vinyl / conjugated diene block copolymer (B) is a monomer unit derived from 1,2-addition polymerization, or a monomer unit derived from 3,4-addition polymerization. 1,4-addition polymerization-derived monomer units.

本発明において、共役ジエン化合物由来の単量体単位中の３，４−付加重合由来の単量体単位とは、例えば、共役ジエン化合物として２−メチル−１，３−ペンタジエンを用いた場合に、３，４−付加重合して得られる式（３）で表される単量体単位である。

本発明において、共役ジエン化合物由来の単量体単位中の１，４−付加重合由来の単量体単位とは、例えば、共役ジエン化合物として２−メチル−１，３−ペンタジエンを用いた場合に、１，４−付加重合して得られる式（４）又は式（５）で表される単量体単位である。

共役ジエン化合物由来の単量体単位中の、１，２−、３，４−および１，４−付加重合由来の単量体単位の割合は、赤外分析法を用い、モレロ法により算出することが出来る。 In the present invention, the monomer unit derived from 1,2-addition polymerization in the monomer unit derived from the conjugated diene compound is, for example, when 2-methyl-1,3-pentadiene is used as the conjugated diene compound. The monomer unit represented by the formula (2) obtained by 1,2-addition polymerization.

In the present invention, the monomer unit derived from 3,4-addition polymerization in the monomer unit derived from the conjugated diene compound is, for example, when 2-methyl-1,3-pentadiene is used as the conjugated diene compound. The monomer unit represented by the formula (3) obtained by 3,4-addition polymerization.

In the present invention, the monomer unit derived from 1,4-addition polymerization in the monomer unit derived from the conjugated diene compound is, for example, when 2-methyl-1,3-pentadiene is used as the conjugated diene compound. 1,4-addition polymerization is a monomer unit represented by Formula (4) or Formula (5).

The ratio of the monomer units derived from 1,2-, 3,4- and 1,4-addition polymerization in the monomer units derived from the conjugated diene compound is calculated by the Morero method using infrared analysis. I can do it.

  Most preferably, the double bond in the monomer unit derived from the conjugated diene compound is not hydrogenated, but the hydrogenation rate of the double bond is usually 10% or less, preferably 1% or less, more preferably 0.1% or less.

  The aromatic vinyl / conjugated diene block copolymer (B) may be a polymer in which a polymer molecular chain is extended or branched through a coupling agent residue by using a coupling agent. Coupling agents used at this time include diethyl adipate, divinylbenzene, methyldichlorosilane, silicon tetrachloride, butyltrichlorosilicon, tetrachlorotin, butyltrichlorotin, dimethylchlorosilicon, tetrachlorogermanium, 1,2-dibromo. Examples include ethane, 1,4-chloromethylbenzene, bis (trichlorosilyl) ethane, epoxidized linseed oil, tolylene diisocyanate, 1,2,4-benzene triisocyanate, and the like.

  The aromatic vinyl / conjugated diene block copolymer (B) used in the present invention is not limited by its production method. For example, an aromatic vinyl compound and a conjugated diene compound are started in an organic solvent with an organic alkali metal compound. And a living anionic polymerization method used as an agent.

The monomer units derived from 1,2- and 3,4-addition polymerization in the monomer units derived from the conjugated diene compound of the aromatic vinyl / conjugated diene block copolymer (B) used in the present invention. This ratio can be prepared by using a Lewis base in combination with the polymerization reaction.
Examples of the Lewis base include ethers such as diethyl ether, tetrahydrofuran, and ethylene glycol dibutyl ether; amines such as tetramethylethylenediamine, pyridine, and tributylamine.

The number average molecular weight of the aromatic vinyl / conjugated diene block copolymer (B) is not particularly limited, but is preferably in the range of 50,000 to 700,000, and more preferably in the range of 50,000 to 600,000. Preferably, it is especially preferable in the range of 50,000 to 400,000.
When the number average molecular weight is within this range, the processability of the aromatic vinyl / conjugated diene block copolymer (B) is excellent, and when the hydride is pelletized, it is difficult to block and contains an alicyclic structure. When blended with a polymer, the mechanical strength, molding appearance, and molding processability of the resulting heat-shrinkable film are excellent.

The melt mass flow rate (MFR) of the aromatic vinyl / conjugated diene block copolymer (B) is not particularly limited, but is preferably 0.1 to 20 g / 10 minutes, more preferably 0.5 to 20 g / 10 minutes, particularly Preferably it is 0.5-10g / 10min, Most preferably, it is 1-5g / 10min.
When the MFR is in this range, the extrudability and layer forming property of the resulting aromatic vinyl / conjugated diene block copolymer (B) are excellent.
In the present invention, the MFR of the aromatic vinyl / conjugated diene block copolymer (B) is a value measured in accordance with ASTM D1238 (190 ° C., load 21.18 N).

(Resin composition (C))
The resin composition (C) used in the present invention comprises an alicyclic structure-containing polymer (A) and an aromatic vinyl / conjugated diene block copolymer having an aromatic vinyl block ratio of 10 to 30% by weight ( B) is contained, and (A) / (B) is in the range of 85/15 to 70/30 by weight.
Among them, (A) / (B) is preferably in the range of 84/16 to 75/25 by weight, and more preferably in the range of 83/17 to 80/20.

  The resin composition (C) used in the present invention is an aromatic vinyl / conjugated diene block copolymer in which the ratio of the alicyclic structure-containing polymer (A) and the aromatic vinyl block is 10 to 30% by weight. It is obtained by adding a compounding agent to (B) as necessary within a range not impairing the effects of the invention.

(Combination agent)
Compounding agents include antioxidants, lubricants, flame retardants, anti-blocking agents, mold release agents, light stabilizers, UV absorbers, antistatic agents, dispersants, thermal stabilizers, nucleating agents, dispersants, and chlorine scavengers. Agents, crystallization nucleating agents, antifogging agents, pigments, dyes, organic fillers, inorganic fillers, neutralizers, decomposing agents, metal deactivators, antifouling agents, antibacterial agents, and other types of polymers (Rubber or resin).

In the present invention, it is preferable to use an antioxidant for the purpose of preventing oxidation during storage, storage, oxidation deterioration during long-term use, and aging deterioration.
Antioxidants include phenolic antioxidants, phosphorus antioxidants, sulfur antioxidants, etc. Among these, phenolic antioxidants are preferred, and alkyl-substituted phenolic antioxidants are more preferred. .

  Examples of phenolic antioxidants include 2,6-di-t-butyl-4-methylphenol, 2,6-di-t-butyl-4-ethylphenol, and octadecyl-3- (3,5-di-t. -Butyl-4-hydroxyphenyl) propionate, 2,2'-methylene-bis (4-methyl-6-t-butylphenol), 4,4'-butylidene-bis (6-t-butyl-m-cresol), 4,4′-thiobis (3-methyl-6-tert-butylphenol), bis (3-cyclohexyl-2-hydroxy-5-methylphenyl) methane and the like can be mentioned.

  Examples of phosphorus antioxidants include triphenyl phosphite, diphenylisodecyl phosphite, phenyl diisodecyl phosphite, and tris (nonylphenyl) phosphite.

  Sulfur-based antioxidants include dilauryl 3,3′-thiodipropionate, dimyristyl-3,3′-thiodipropionate, distearyl 3,3′-thiodipropionate, lauryl stearyl 3,3′- Thiodipropionate, pentaerythritol-tetrakis- (β-lauryl-thio-propionate), 3,9-bis (2-dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane Etc.

  These antioxidants can be used alone or in combination of two or more, but it is preferable to use two or more in combination. When used in combination, the combined use of a phenolic antioxidant and a phosphorus-based antioxidant is preferable because of its excellent transparency. Although the compounding quantity of antioxidant is selected suitably, it is 0.001-5 weight part normally with respect to 100 weight part of alicyclic structure containing polymers, Preferably it is the range of 0.01-1 weight part. .

  A lubricant can be used for the purpose of improving moldability such as releasability. Examples of the lubricant include inorganic fine particles, natural oils, synthetic oils, waxes, higher fatty acid amides such as lauric acid amides and oleic acid amides. Here, the inorganic fine particles are oxides of elements of Group 1, Group 2, Group 4, Group 6, Group 7, Group 8 to 10, Group 11, Group 12, Group 13 or Group 14 of the Long Periodic Table. Particles such as hydroxide, sulfide, nitride, halide, carbonate, sulfate, acetate, phosphate, phosphite, organic carboxylate, silicate, titanate, or borate A particulate form of a hydrous compound of these compounds or salts; a particulate monomer of a composite compound having these salt centers, or natural mineral particles mainly composed of these salts;

  These lubricants can be used alone or in combination of two or more. Although the compounding quantity of a lubrication agent is selected suitably, it is 0.001-5 weight part normally with respect to 100 weight part of alicyclic structure containing polymers, Preferably it is the range of 0.005-3 weight part. When the blending amount is within this range, the transparency of the heat-shrinkable film and the moldability at the time of molding are highly balanced.

  Examples of the flame retardant include phosphoric acid flame retardant, antimony trioxide, magnesium hydroxide, aluminum hydroxide, magnesium carbonate, red phosphorus, and the like. Among these, a phosphoric acid flame retardant is preferable from the viewpoint of dispersibility.

  Examples of the antiblocking agent include fine particles of silica, silica alumina, natural zeolite, synthetic zeolite, kaolin, talc, silicone resin, silicone rubber, fused silica, melamine resin, acrylic resin, hydrotalcite, and the like.

  Examples of the release agent include etherified products of polyhydric alcohols and esterified products of polyhydric alcohols.

  Examples of etherified polyhydric alcohols include glycerol monostearate, glycerol monolaurate, glycerol monobehenate, diglycerol monostearate, glycerol distearate, glycerol dilaurate, pentaerythritol monostearate, pentaerythritol monolaurate, Examples include pentaerythritol monobeherate, pentaerythritol distearate, pentaerythritol dilaurate, pentaerythritol tristearate, dipentaerythritol distearate, and the like.

  Examples of esterified polyhydric alcohols include 3- (octyloxy) -1,2-propanediol, 3- (decyloxy) -1,2-propanediol, 3- (lauryloxy) -1,2-propanediol, 3- (4-nonylphenyloxy) -1,2-propanediol, 1,6-dihydroxy-2,2-di (hydroxymethyl) -7- (4-nonylphenyloxy) -4-oxoheptane, p -Ether compound obtained by reaction of nonylphenol-formaldehyde condensate with glycidol, ether compound obtained by reaction of p-octylphenol-formaldehyde condensate with glycidol, reaction of p-octylphenol-dicyclopentadiene condensate with glycidol Examples include ether compounds obtained

The molecular weight of the etherified product and esterified product of these polyhydric alcohols is not particularly limited, but is preferably in the range of 500 to 2,000, and more preferably in the range of 800 to 1,500. When the molecular weight is within this range, it is preferable because the etherified product and esterified product of polyhydric alcohol are difficult to elute and the decrease in transparency is small.
These polyhydric alcohol etherified products and esterified products can be used alone or in combination of two or more. The blending amount of the polyhydric alcohol etherified product and esterified product is appropriately selected depending on the purpose of use, but is usually 0.01 to 5 parts by weight, preferably 100 parts by weight of the alicyclic structure-containing polymer. 0.05 to 2 parts by weight, particularly preferably 0.1 to 1.0 parts by weight. When the addition amount is within this range, the moldability of the obtained resin composition and the low elution property of the obtained heat-shrinkable film are highly balanced, which is preferable.

Examples of the light stabilizer include hindered amine stabilizers.
Examples of ultraviolet absorbers include benzophenone ultraviolet absorbers and benzotriazole ultraviolet absorbers.
Examples of the antistatic agent include nonionic antistatic agents, cationic antistatic agents, anionic antistatic agents, zwitterionic antistatic agents, inorganic fillers, and carbon nanotubes. Among these, nonionic antistatic agents, cationic antistatic agents, anionic antistatic agents, and carbon nanotubes are preferable from the viewpoints of transparency and dispersibility.
Examples of the dispersant include a bisamide dispersant, a wax dispersant, and an organic metal salt dispersant.

  Other types of polymers (rubbers and resins) include olefin polymers such as polyethylene and polypropylene; isobutylene polymers such as polyisobutylene and isobutylene / isoprene rubber; acrylics such as polybutyl acrylate and polyhydroxyethyl methacrylate Polymers; Polymers of vinyl compounds such as polyvinyl alcohol, polyvinyl acetate, vinyl acetate / styrene copolymers; Epoxy polymers such as polyethylene oxide, polypropylene oxide, epichlorohydrin rubber; Vinylidene fluoride rubber, Tetrafluoroethylene -Fluoropolymers such as propylene rubber; These polymers may have a crosslinked structure, or may have a functional group introduced by a modification reaction.

  These other types of polymers (rubber and resin) can be used alone or in combination of two or more. The amount of the other type of polymer (rubber or resin) is appropriately selected, but is usually less than 5 parts by weight, preferably less than 2 parts by weight, based on 100 parts by weight of the alicyclic structure-containing polymer. The range is preferably less than 1 part by weight, particularly preferably less than 0.3 part by weight. When the blending amount of other types of polymers (rubber and resin) is within this range, the transparency of the heat-shrinkable film and the moldability at the time of molding are highly balanced.

The preparation method of the resin composition (C) used for this invention is not specifically limited.
For example, the alicyclic structure-containing polymer (A) and the aromatic vinyl / conjugated diene block copolymer (B) in which the ratio of the aromatic vinyl block is 10 to 30% by weight, and optionally used. A method of mixing the compounding agent with a mixer such as a Henschel mixer, a V blender, a ribbon blender, a tumbler blender, or a conical blender; or, after this mixing, melt kneading using a single screw extruder, twin screw extruder, kneader or the like Method: After adding and dispersing a solution in which a compounding agent used as necessary is dispersed in the solution of the alicyclic structure-containing polymer (A), the solvent is removed by a coagulation method, a cast method, or a direct drying method. A method of mixing an aromatic vinyl / conjugated diene block copolymer (B) having a ratio of the aromatic vinyl block of 10 to 30% by weight after removal; After mixing the compounding agent used as needed in the reaction or hydrogenation reaction stage, the aromatic vinyl block conjugated diene block copolymer (B) in which the ratio of the aromatic vinyl block is 10 to 30% by weight is mixed. And the like.

(Heat shrinkable film)
The heat-shrinkable film of the present invention has at least one layer formed by stretching a film made of the resin composition (C).

  The method for molding the heat-shrinkable film of the present invention is not particularly limited. For example, a (unstretched) film made of the resin composition (C) was obtained by a known method such as a T-die method, an inflation method, or a press molding method. Thereafter, this (unstretched) film can be obtained by stretching.

  The thickness of the unstretched film is usually in the range of 50 to 500 μm, and preferably in the range of 50 to 300 μm.

  The method for stretching the unstretched film is not particularly limited, and for example, any of a roll method, a tenter method, and a tube method can be performed. The stretching temperature is preferably 0 to 60 ° C., preferably 10 to 40 ° C. higher than the glass transition temperature (Tg) of the alicyclic structure-containing polymer constituting the unstretched film. In the present invention, either uniaxial stretching or biaxial stretching may be used, but it is preferable to stretch in uniaxial stretching (lateral direction; TD direction). Although the draw ratio is not particularly limited, it is preferably in the range of 1.2 to 10.0 times in the TD direction, and particularly preferably in the range of 2.0 to 6.0 times. Even in uniaxial stretching, a stretching process can be performed at a low stretching ratio (for example, 1.5 times or less) in the length direction (longitudinal direction; MD direction) as necessary. In the present invention, the uniaxially stretched film stretched only in one direction and the biaxially stretched film stretched mainly in one direction and slightly stretched in the direction orthogonal to the direction are included.

  The heat-shrinkable film of the present invention is preferably a single-layer film composed only of the stretched layer (I) of the resin composition (C), but if necessary, a layer (II) composed of another resin is laminated. A laminated film may be used. The lamination mode of the laminated film is not particularly limited. For example, layer (I) / layer (II), layer (I) / layer (II) / layer (I), layer (II) / layer (I) / layer (II It is also possible to stack them as shown in FIG. Especially, it is preferable to laminate | stack layer (I) on the film surface which contacts sebum. Further, the laminated film may include an adhesive layer between the layers (I) and (II).

Other resins used here include low-density or high-density polyethylene crystalline resin, polypropylene crystalline resin, polyester crystalline resin, polyamide crystalline resin, fluorine crystalline resin, and other crystalline resins. Is mentioned. Among these, a polyethylene crystalline resin and a polypropylene crystalline resin are good in terms of balance of moisture resistance, mechanical strength, etc. of the heat shrinkable film.
Adhesives constituting the adhesive layer include thermosetting resin adhesives such as epoxy resins, silicone resins and urethane resins, thermoplastic resin adhesives such as polyvinyl ether, acrylic resins and vinyl acetate-ethylene copolymers, and polyamide resins. And hot-melt adhesives, and rubber adhesives such as nitrile rubber.

When the heat-shrinkable film of the present invention is a laminated film, the production method is not particularly limited.
(I) By stretching after bonding a film made of another resin to the single-layer unstretched film of the resin composition (C),
(II) By stretching a single-layer film of the resin composition (C) and bonding a stretched or unstretched film made of another resin to it,
(III) By applying a solution of another resin to the single-layer unstretched film of the resin composition (C), drying, and stretching,
(IV) by coating the stretched film of the resin composition (C), or
(V) The resin composition (C) and another resin can be obtained by co-extrusion such as co-extrusion T-die method, co-extrusion inflation method, co-extrusion lamination method and the like.

  The ratio of the thickness of the stretched layer (I) of the resin composition (C) and the layer (II) made of another resin is not particularly limited. For example, the ratio of the layer (I) / layer (II) is 1/8 to 8/1 is preferred.

  The thickness of the heat-shrinkable film of the present invention is not particularly limited, but is preferably in the range of 5 to 400 μm, more preferably in the range of 25 to 250 μm, and particularly preferably in the range of 8 to 150 μm. When the thickness is within this range, the heat-shrinkable film has excellent tear resistance and transparency.

  The heat-shrinkable film of the present invention has a temperature atmosphere in the range of 20 ° C. to 80 ° C. higher than the glass transition temperature (Tg) of the alicyclic structure polymer (A), for example, in the range of 60 to 120 ° C. When held below, heat shrinkage occurs, and the heat shrinkage rate in the stretching direction is usually in the range of 30 to 90%, preferably in the range of 50 to 80%. When the heat shrinkage ratio is in this range, the adhesiveness of the heat shrinkable film to the package and the various physical properties of the film after heat shrink are highly balanced.

The heat-shrinkable film of the present invention is excellent in finger oil whitening resistance and surface gloss.
The surface glossiness of the heat-shrinkable film of the present invention is not particularly limited, but the surface glossiness is preferably 120 to 150%, more preferably 130 to 150%, and particularly preferably 140 to 150%.
When the surface glossiness is in this range, it is excellent from the viewpoint of design.
In the present invention, the surface glossiness is a value obtained by measuring the 60 ° specular glossiness based on JIS K 7105.

The value (d (haze) (%)) obtained by subtracting the haze before coating from the haze value after coating / shrinking of the heat-shrinkable film of the present invention is not particularly limited, but is preferably 1% or less. It is more preferably 6% or less, and particularly preferably 0.5% or less. When d (haze) (%) is within this range, the heat-shrinkable film is easy to handle, and the design of the film after heat-shrinking the heat-shrinkable film is excellent.
In the present invention, a value (d (haze) (%)) obtained by subtracting the haze before application from the haze value after application / shrinkage is a value obtained by the following method.
(Method) A heat-shrinkable film is cut into a size of 100 mm length × 100 mm width, and the haze is measured with a haze meter according to JIS K 7105. Next, finger oil equivalent (mixed reagent consisting of 50% oleic acid, 40% stearyl palmitate and 10% squalene) is applied onto the heat shrinkable film. Next, the heat-shrinkable film is immersed in a 90 ° C. hot water bath for 10 seconds to be heat-shrinked. Next, the film is taken out and the haze is measured with a haze meter according to JIS K 7105. The value obtained by subtracting the haze before coating from the haze value after coating and shrinkage was defined as d (haze) (%). The smaller the d (haze) (%), the better the finger fat whitening resistance.

The heat-shrinkable film of the present invention is excellent in finger oil whitening resistance and surface gloss, and is also excellent in moisture resistance, mechanical strength, transparency, and heat-shrink characteristics. Because of these characteristics, the heat-shrinkable film of the present invention is a heat-shrinkable packaging material for storing and transporting foods, drugs, utensils, stationery, notebooks, and other miscellaneous goods; Suitable for heat-shrinkable label materials such as bottles and containers.
In addition, the heat-shrinkable film of the present invention is excellent in finger whitening resistance and surface glossiness, has a high heat-resistant temperature, is transparent and has good shrinkage, and is also suitable for labels such as heat-resistant polyethylene terephthalate (PET) bottles. Is preferred.

  There is no particular limitation on the method for shrink-wrapping the package body with the heat-shrinkable film of the present invention. As a general method, a film to be wrapped is roughly wrapped with the film, and then heated through a hot air tunnel (hereinafter referred to as a shrink tunnel). A method is used in which the product is packaged closely.

  You may give a printing process to the heat-shrinkable film of this invention. The printing method is not particularly limited, and a known method may be used. Examples thereof include relief printing, intaglio printing, and flat printing. The type of printing ink applied to printing may be appropriately selected and used depending on the printing method. For example, letterpress ink, flexographic ink, dry offset ink, gravure ink, gravure offset ink, offset Examples thereof include ink and screen ink.

  Printing ink is at least a colorant (including pigments, dyes, etc.), vehicle (a mixture of oils and fats, resins, and solvents). As oils and fats, drying oils, semi-drying oils, non-drying oils, processing oils, etc .; Is a general natural resin, synthetic resin; solvents include hydrocarbon solvents, ester solvents, ketone solvents, alcohol solvents, aqueous solvents) and auxiliary agents (compounds, dryers, other dispersants, The type and composition of the printing ink depending on the type and purpose of use of the alicyclic structure-containing polymer resin in the heat-shrinkable film of the present invention to be printed. Is appropriately selected. Further, before using the printing ink, the heat-shrinkable film of the present invention may be subjected to a surface treatment for the purpose of enhancing the adhesion of the ink. As the surface treatment method, corona discharge treatment, plasma discharge treatment may be used. , Flame treatment, embossing treatment, sand matting treatment, and satin finishing treatment.

EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples and comparative examples. However, the present invention is not limited only to these examples. Unless otherwise specified, parts and% are based on weight, and pressure is gauge pressure. The measuring method of the physical property in an Example and a comparative example is as follows.
(1) Weight average molecular weight (Mw)
Measured by gel permeation chromatography (GPC) using tetrahydrofuran (THF) as a solvent, and determined in terms of standard polystyrene.
(2) Glass transition temperature (Tg)
Measured by differential scanning calorimetry (DSC method) based on JIS K7121.
(3) Hydrogenation rate of alicyclic structure-containing polymer The hydrogenation rate of the polymer main chain and aromatic ring is calculated by measuring ¹ H-NMR.
(4) Film thickness Measured using a micro gauge.
(5) Transparency (haze (%))
A heat-shrinkable film or an unstretched film is measured with a haze meter according to JIS K 7105. A smaller haze value indicates better transparency.
(6) Surface glossiness (%)
A 60 degree specular glossiness is measured for a heat-shrinkable film or an unstretched film based on JIS K 7105. The higher the glossiness, the better.
(7) Finger oil whitening resistance (d (haze) (%))
The heat-shrinkable film is cut into a size of 100 mm long × 100 mm wide and the haze is measured with a haze meter according to JIS K 7105. Next, finger oil equivalent (mixed reagent consisting of 50% oleic acid, 40% stearyl palmitate and 10% squalene) is applied onto the heat shrinkable film. Next, the heat-shrinkable film is immersed in a 90 ° C. hot water bath for 10 seconds to be heat-shrinked. Next, the film is taken out and the haze is measured with a haze meter according to JIS K 7105. The value obtained by subtracting the haze before coating from the haze value after coating and shrinkage was defined as d (haze) (%). The smaller the d (haze) (%), the better the finger fat whitening resistance.
(8) Shrinkage rate (%)
The heat-shrinkable film is cut into a size of 100 mm long × 100 mm wide and immersed in a 90 ° C. hot water bath for 10 seconds. The shrinkage rate is the ratio of change in length before and after immersion (%) (= (film length in TD direction before immersion−film length in TD direction after immersion)) / (film length in TD direction before immersion) in the TD direction. Film length) × 100) is calculated. It is favorable when the shrinkage rate is in the range of 50% to 80%.
(9) Ratio of aromatic vinyl block in aromatic vinyl / conjugated diene block copolymer (B) A calibration curve is prepared and determined for absorption based on a phenyl group of 679 cm ⁻¹ by infrared analysis.
(10) Ratio of monomer units derived from 1,2- and 3,4-addition polymerization in monomer units derived from a conjugated diene compound Calculated by the Morero method using an infrared analysis method.

(Reference Example 1)
In a nitrogen atmosphere, 500 parts of dehydrated cyclohexane, 0.82 part of 1-hexene, 0.15 part of dibutyl ether, and 0.30 part of triisobutylaluminum were mixed in a reactor at room temperature, and then maintained at 45 ° C. , 160 parts of tricyclo [4.3.01, 6.12,5] deca-3,7-diene (dicyclopentadiene, hereinafter abbreviated as “DCP”), and bicyclo [2.2.1] hept. 40 parts of 2-ene (norbornene, hereinafter abbreviated as “NB”) and 80 parts of tungsten hexachloride (0.7% toluene solution) were continuously added and polymerized over 2 hours. To the polymerization solution, 1.06 part of butyl glycidyl ether and 0.52 part of isopropyl alcohol were added to deactivate the polymerization catalyst and stop the polymerization reaction.

  Next, 270 parts of cyclohexane is added to 100 parts of the reaction solution containing the obtained ring-opening polymer, and further 5 parts of a nickel-alumina catalyst (manufactured by JGC Chemical Co., Ltd.) is added as a hydrogenation catalyst. The mixture was heated to 200 ° C. while being pressurized and stirred, and then reacted for 4 hours to obtain a reaction solution containing 20% of a DCP / NB ring-opening copolymer hydrogenated product. The hydrogenation catalyst is removed by filtration, and then 0.1 part of a hindered phenolic antioxidant (manufactured by Yoshitomi Pharmaceutical; Tominox TT) per 100 parts of the hydrogenated product is added to the resulting solution and dissolved. I let you. Next, using a cylindrical concentrating dryer (manufactured by Hitachi, Ltd.), at a temperature of 270 ° C. and a pressure of 1 kPa or less, cyclohexane and other volatile components as solvents are removed from the solution, and then the hydride is extruded in a molten state. Were extruded into strands, cooled and pelletized to obtain pellets. The pelletized ring-opening copolymer hydrogenated product had a weight average molecular weight (Mw) of 35,000, a hydrogenation rate of 99.8%, a Tg of 70 ° C., and a specific gravity of 1.01.

Example 1
82.5 parts of the alicyclic structure-containing polymer obtained in Reference Example 1 and aromatic vinyl / conjugated diene block copolymer B1 (manufactured by Kuraray Co., Ltd., Hibler 5125: styrene / isoprene block copolymer, aromatic vinyl block) And 17.5 parts of monomer units derived from 1,2- and 3,4-addition polymerization) were mixed in a blender and then dried at 55 ° C. for 4 hours. Next, a resin melt that is equipped with a screw with a screw diameter of 50 mmφ, a compression ratio of 2.5, and L / D = 30, and three 40, 80, and 120 mesh filters provided in front of the T-die to allow the molten resin to pass through. Using a hanger manifold type T-die film melt extrusion molding machine with a kneading machine, die lip 0.5mm, molten resin temperature 200 ° C, T-die temperature 220 ° C, T-die width 300mm, cast roll temperature 60 An unstretched film (C1) having a thickness of 100 μm was obtained under the conditions of ℃ and cooling roll temperature of 50 ℃. Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C1).
During molding, nitrogen was introduced into the hopper from the lower part of the hopper. When bringing the unstretched film (C1) into close contact with the cast roll, an air knife was used.
The obtained unstretched film (C1) was stretched 5 times in the TD direction by using a tender stretching machine under the condition of atmospheric temperature Tg + 20 ° C. (90 ° C.) to obtain a heat-shrinkable film (D1) having a thickness of 20 μm. It was. The measurement results and evaluation results of the obtained heat-shrinkable film (D1) are shown in Table 1.

(Example 2)
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, the aromatic vinyl / conjugated diene block copolymer B2 (styrene / isoprene block copolymer, aromatic Unstretched film in the same manner as in Example 1 except that 20 parts of a vinyl group block proportion of 13 wt% and 1,2- and 3,4-addition polymerization-derived monomer units of 70 wt% were used. C2) was obtained and stretched to obtain a heat-shrinkable film (D2). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C2) and heat-shrinkable film (D2).

(Example 3)
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, an aromatic vinyl / conjugated diene block copolymer B3 (styrene / isoprene block copolymer, aromatic Unstretched film in the same manner as in Example 1 except that 20 parts by weight of the vinyl group block and 70 parts by weight of the monomer units derived from 1,2- and 3,4-addition polymerization were used. C3) was obtained and stretched to obtain a heat-shrinkable film (D3). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C3) and heat-shrinkable film (D3).

Example 4
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, an aromatic vinyl / conjugated diene block copolymer B4 (manufactured by Nippon Zeon Co., Ltd., QUINTAC 3450: Except for using 20 parts of styrene / isoprene block copolymer, 19% by weight of aromatic vinyl block, 8% by weight of monomer units derived from 1,2- and 3,4-addition polymerization) In the same manner as in Example 1, an unstretched film (C4) was obtained and stretched to obtain a heat-shrinkable film (D4). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C4) and heat-shrinkable film (D4).

(Example 5)
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, an aromatic vinyl / conjugated diene block copolymer B5 (styrene / isoprene block copolymer, aromatic Unstretched film in the same manner as in Example 1 except that 20 parts by weight of the vinyl group 19% and 50 parts by weight of the monomer units derived from 1,2- and 3,4-addition polymerization are used. C5) was obtained and stretched to obtain a heat-shrinkable film (D5). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C5) and heat-shrinkable film (D5).

(Comparative Example 1)
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, an aromatic vinyl / conjugated diene block copolymer B6 (styrene / isoprene block copolymer, aromatic Unstretched film in the same manner as in Example 1 except that 20 parts by weight of the vinyl group block and 7 parts by weight of monomer units derived from 1,2- and 3,4-addition polymerization (70 weight%) were used. C6) was obtained and stretched to obtain a heat-shrinkable film (D6). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C5) and heat-shrinkable film (D6).

(Comparative Example 2)
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, an aromatic vinyl / conjugated diene block copolymer B7 (styrene / isoprene block copolymer, aromatic Unstretched film in the same manner as in Example 1 except that 20 parts of a vinyl group block proportion of 33 wt% and 1,2- and 3,4-addition-derived monomer units proportion of 70 wt% are used. C7) was obtained and stretched to obtain a heat-shrinkable film (D7). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C7) and heat-shrinkable film (D7).

(Comparative Example 3)
Unstretched film (C8) in the same manner as in Example 1 except that the amount of the alicyclic structure-containing polymer was changed to 90 parts and the amount of the aromatic vinyl / conjugated diene block copolymer B1 was changed to 10 parts. Was stretched to obtain a heat-shrinkable film (D8). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C8) and heat-shrinkable film (D8).

(Comparative Example 4)
An unstretched film (C9) in the same manner as in Example 1, except that the amount of the alicyclic structure-containing polymer was changed to 80 parts and the blending amount of the aromatic vinyl / conjugated diene block copolymer B1 was changed to 35 parts. Was stretched to obtain a heat-shrinkable film (D9). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C9) and heat-shrinkable film (D9).

(Comparative Example 5)
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, a hydride of aromatic vinyl / conjugated diene block copolymer (Kuraray Co., Ltd., Hibler 7125: Unstretched film (C10) in the same manner as in Example 1 except that 20 parts of hydride of styrene / isoprene block copolymer and 63% of double bond hydrogenation ratio in monomer units derived from isoprene are used. Was stretched to obtain a heat-shrinkable film (D10). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C10) and heat-shrinkable film (D10).

(Comparative Example 6)
The amount of the alicyclic structure-containing polymer is changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, the aromatic vinyl / conjugated used in Example 2 of JP-A-2000-143829 is disclosed. An unstretched film (C11) was obtained in the same manner as in Example 1, except that 20 parts of a hydride of a diene block copolymer (Asahi Kasei Corporation, Tuftec H1051G: styrene / ethylene / butylene / block copolymer) was used. This was stretched to obtain a heat-shrinkable film (D11). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C11) and heat-shrinkable film (D11).

(Comparative Example 7)
The amount of the alicyclic structure-containing polymer was changed to 80 parts, and instead of the aromatic vinyl / conjugated diene block copolymer B1, a hydride (styrene / butadiene / random copolymer) of an aromatic vinyl / conjugated diene random copolymer was used. An unstretched film (C12) was obtained in the same manner as in Example 1 except that 20 parts of the combined hydride) was used, and this was stretched to obtain a heat-shrinkable film (D12). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C12) and heat-shrinkable film (D12).

(Comparative Example 8)
The ethylene / propylene random copolymer used in Example 2 of JP-A-8-165357 is used instead of the aromatic vinyl / conjugated diene block copolymer B1 in an amount of 82 parts of the alicyclic structure-containing polymer. An unstretched film (C13) was obtained in the same manner as in Example 1 except that 20 parts of a polymer (ethylene content 80 mol%, glass transition temperature -45 ° C, intrinsic viscosity 2.2 dl / g) was used. The film was stretched to obtain a heat-shrinkable film (D13). Table 1 shows the measurement results and evaluation results of the obtained unstretched film (C13) and heat-shrinkable film (D13).

  From the results in Table 1, the following can be understood. The alicyclic structure-containing polymer (A) of the present invention contains an aromatic vinyl / conjugated diene block copolymer (B) in which the ratio of the aromatic vinyl block is 10 to 30% by weight, (A) A heat-shrinkable film having at least one layer formed by stretching a film made of the resin composition (C) having a weight ratio of / (B) in the range of 85/15 to 70/30 is finger grease whitening resistance. And excellent surface gloss (Examples 1 to 5). In contrast, when an aromatic vinyl / conjugated diene block copolymer (B) in which the ratio of the aromatic vinyl block is not in the range of 10 to 30% by weight is used. The surface gloss is inferior (Comparative Examples 1 and 2). Further, a heat shrinkable film in which (A) / (B) is greater than 85/15 by weight ratio is inferior in finger whitening resistance (Comparative Example 3), and a heat shrinkable film smaller than 70/30 has surface gloss. Inferior (Comparative Example 4). A heat-shrinkable film using a hydride of a styrene / isoprene block copolymer instead of the aromatic vinyl / conjugated diene block copolymer (B) has poor surface gloss (Comparative Example 5). A heat-shrinkable film using a hydride of a styrene / butadiene block copolymer in place of the aromatic vinyl / conjugated diene block copolymer (B) is inferior in finger whitening resistance and surface gloss (Comparative Example 6). . A heat shrinkable film using a hydride of a styrene / butadiene random copolymer instead of the aromatic vinyl / conjugated diene block copolymer (B) has poor surface gloss (Comparative Example 7). A heat-shrinkable film using an ethylene / propylene random copolymer instead of the aromatic vinyl / conjugated diene block copolymer (B) is inferior in finger whitening resistance and surface gloss (Comparative Example 8).

  Since the heat-shrinkable film of the present invention is excellent in finger fat whitening resistance and surface gloss, it can be used as various packaging materials or packaging materials.

Claims (4)

  It contains an alicyclic structure-containing polymer (A) and an aromatic vinyl / conjugated diene block copolymer (B) in which the ratio of the aromatic vinyl block is 10 to 30% by weight, and (A) / (B) A heat-shrinkable film having at least one layer formed by stretching a film made of the resin composition (C) having a weight ratio of 85/15 to 70/30.   The heat-shrinkable film according to claim 1, wherein the aromatic vinyl / conjugated diene block copolymer (B) is a block copolymer of styrene and isoprene.   The proportion of monomer units derived from 1,2- and 3,4-addition polymerization in the monomer units derived from the conjugated diene compound of the aromatic vinyl / conjugated diene block copolymer (B) is 60% by weight or more. The heat-shrinkable film according to claim 1 or 2.   The heat-shrinkable film according to claim 1, 2, 3, or 4, having a surface glossiness of 120 to 150%.