JP6513919B2 - Shrink label - Google Patents

Description

  The present invention relates to shrink labels. More particularly, the present invention relates to a shrink label suitable for use in, for example, a container for beverages, foods, toiletries, pharmaceuticals and the like.

  At present, plastic bottles such as PET bottles and metal bottles such as bottle cans are widely used as containers for beverages such as tea and soft drinks. These containers are often equipped with plastic labels for display, decoration, or functional addition. For example, due to merits such as decoration, processability (followability to containers), wide display area, etc., shrink A shrink label or the like in which a print layer is provided on a film (heat shrinkable film) is widely used.

  As the above-mentioned shrink film, a heterogeneous laminated film in which different resin materials are laminated is known for the purpose of imparting various functions to the film. As such a shrink film, for example, a resin layer (A layer) containing an aromatic polyester resin, a resin layer containing 5 to 40% by weight of an aromatic polyester resin and 50 to 95% by weight of a polyolefin resin ( Layer B) and a resin layer (C layer) containing a polypropylene-based resin have a laminated structure in which the layers A, B, and C are laminated in the order of A layer / B layer / C layer, without using any other layer. There is known a shrink film comprising 35 to 75% by weight of a structural unit derived from ethylene, 15 to 60% by weight of a structural unit derived from propylene, and a structural unit derived from butene (see Patent Document 1). According to the above-mentioned shrink film, it is a heterogeneous laminated film having a resin layer composed of a polypropylene-based resin and a resin layer composed of an aromatic polyester-based resin, and at the time of shrink processing also at normal temperature (especially high temperature shrink Even during processing), it is possible to obtain a shrink film which has high interlayer strength and is hard to cause delamination. Such a different kind of laminated film having a resin layer composed of a polyester resin and a resin layer composed of a polypropylene resin comprises a resin layer composed of a polyester resin and a resin layer composed of a polyolefin resin By combining these, it is difficult to generate wrinkles and the like at the time of heat shrinkage, and the finish after shrinking is good, and a shrink film having a relatively high heat shrinkage rate and rigidity is obtained, which is preferable.

JP, 2013-226711, A

  However, a shrink label having a shrink film having a resin layer composed of a polyolefin resin as described above as a label substrate has a low rigidity and tends to weaken the rigidity of the label. In addition, such a shrink label tends to have low transparency, and when it is used as a shrink label (back-printed shrink label) to show printing through a shrink film, the print may appear cloudy and the decorativeness may be deteriorated.

  That is, an object of the present invention is to provide a shrink label having high rigidity while retaining the characteristics of different laminated films of polyester resin and polyolefin resin. Another object of the present invention is to provide a shrink label with relatively high transparency.

  That is, the present invention is a shrink label having a shrink film, wherein the shrink film has a base layer portion and surface layers provided on both sides of the base layer portion, and the surface layer is a polyester resin. 50% by weight or more, and the base layer portion includes 5 to 65 layers, and at least a layer (A layer) containing 50% by weight or more of a polyolefin resin as a layer in the base layer portion. Provide a shrink label.

  In the present invention, the base layer portion has at least a layer (B layer) containing 10 to 90% by weight of a polyolefin resin and 10 to 90% by weight of a polyester resin as a layer in the base layer portion. Provide a shrink label.

  The present invention also provides the shrink label, wherein the layer B contains 10 to 60% by weight of a polyolefin resin and 40 to 90% by weight of a polyester resin.

  The present invention also provides the shrink label, wherein the layer B contains 40 to 90% by weight of a polyolefin resin and 10 to 60% by weight of a polyester resin.

  Moreover, this invention provides the said shrink label whose said polyolefin resin is a propylene-alpha-olefin copolymer as polypropylene resin.

  Further, according to the present invention, all the layers in the base layer portion are the A layer, and each A layer in the base layer portion provides the above-described shrink label having a different density from that of the adjacent A layer.

  Since the shrink label of the present invention has a shrink film having a resin layer mainly composed of a polyolefin resin as a label base by having the above specific configuration, the label has high rigidity while the label has high rigidity. It is possible to prevent a defect that causes a mounting defect when mounting a label on a bottle using In addition, since the transparency is relatively high, the decorative property is excellent even when used as a back-printed shrink label.

It is the schematic (partial cross section) which shows an example of the shrink label of this invention. It is the schematic (partial cross section) which shows another example of the shrink label of this invention. It is the schematic which shows an example of the cylindrical shrink label which is one embodiment of the shrink label of this invention. It is the schematic (an essential part enlarged view of the A-A 'cross section of FIG. 3) which shows an example of the cylindrical shrink label which is one Embodiment of the shrink label of this invention.

  The shrink label of the present invention is a shrink label having a shrink film. In the present specification, the above-mentioned shrink film (that is, the shrink film contained in the shrink label of the present invention) may be referred to as "the shrink film of the present invention". The shrink label of the present invention may contain a layer other than the shrink film of the present invention, as long as the effects of the present invention are not impaired.

[Shrink film]
The shrink film of the present invention has a surface layer laminated on both sides of the base layer portion. That is, the shrink film of the present invention includes a base layer portion and surface layers provided on both sides of the base layer portion. Specifically, the shrink film of the present invention has a layer configuration of surface layer / base layer portion / surface layer, and preferably, the base layer portion and the surface layer are directly laminated. The surface layers on both sides of the base layer in the shrink film of the present invention may be the same layer or different layers (layers of different resin composition and layer thickness). It may be. In the shrink film of the present invention, an antistatic layer or an anchor coat layer may be provided on the outer surface of the surface layer as long as the effects of the present invention are not impaired. The surface of the shrink film of the present invention may be subjected to conventional surface treatment such as corona discharge treatment, primer treatment, or flame treatment, as required.

<Surface layer>
The surface layer (that is, the surface layers provided on both sides of the base layer portion) in the shrink film of the present invention is a layer containing 50% by weight or more of a polyester resin in the layer. By having the above-mentioned surface layer, the shrink label of the present invention can improve its rigidity and can strengthen its waist.

  The surface layer contains a polyester resin as an essential component. The said polyester-based resin may use only 1 type, and may use 2 or more types. Moreover, the surface layer is not particularly limited, but may contain a resin other than the above-mentioned polyester resin.

  The polyester-based resin includes, for example, a polyester comprising at least a dicarboxylic acid component and a diol component as essential components (that is, a polyester containing at least a structural unit derived from a dicarboxylic acid (structural unit) and a structural unit derived from a diol And polylactic acid polymers and polyester elastomers. As a main thing of polyester containing the structural unit derived from dicarboxylic acid and the structural unit derived from diol, the polymer by condensation reaction of dicarboxylic acid and diol, a copolymer, or these mixtures are mentioned.

  Examples of the dicarboxylic acid (dicarboxylic acid component) include terephthalic acid, isophthalic acid, phthalic acid, 2,5-dimethylterephthalic acid, 5-t-butylisophthalic acid, 4,4'-biphenyldicarboxylic acid, trans-3 , 3'-stilbenedicarboxylic acid, trans-4,4'-stilbenedicarboxylic acid, 4,4'-dibenzyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,3-naphthalene Dicarboxylic acid, 2,6-naphthalenedicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,2,6,6-tetramethylbiphenyl-4,4'-dicarboxylic acid, 1,1,3-trimethyl-3-phenyl Indene-4,5-dicarboxylic acid, 1,2-diphenoxyethane-4,4'-dicarboxylic acid, diphenyl ether Dicarboxylic acids, 2,5-anthracene dicarboxylic acids, 2,5-pyridine dicarboxylic acids, and aromatic dicarboxylic acids such as their substitution products; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberin Acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, icosanedioic acid, docosanedioic acid, 1, Aliphatic dicarboxylic acids such as 12-dodecanedioic acid and their substitution products; 1,3-cyclopentanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid 1,4-decahydronaphthalenedicarboxylic acid 1,5-decahydronaphth Dicarboxylic acid, 2,6-decahydronaphthalene dicarboxylic acid and an alicyclic dicarboxylic acid such as substituted versions thereof and the like. The dicarboxylic acids may be used alone or in combination of two or more.

  Examples of the diol (diol component) include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol 2,2-dimethyl-1,3-propanediol (neopentyl glycol), 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3 Propanediol, 1,8-octanediol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2,4-dimethyl-1,3-hexanediol, 1,10-decanediol, Aliphatic diols such as polyethylene glycol and polypropylene glycol; 1,2-cyclohexanedimethanol, Alicyclic diols such as 2,3-cyclohexanedimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol; 2,2-bis (4-β-hydroxy) Ethylene oxide adducts of bisphenol compounds such as ethoxyphenyl) propane and bis (4-β-hydroxyethoxyphenyl) sulfone; and aromatic diols such as xylylene glycol. The above diols may be used alone or in combination of two or more.

  In addition to the above, the polyester-based resin is, besides the above, oxycarboxylic acids such as p-hydroxybenzoic acid and p-oxyethoxybenzoic acid; monocarboxylic acids such as benzoic acid and benzoylbenzoic acid; polyvalent carboxylic acids such as trimellitic acid A unit derived from a monohydric alcohol such as polyalkylene glycol monomethyl ether; a polyhydric alcohol such as glycerin, pentaerythritol, trimethylolpropane and the like, and the like.

  Among them, from the viewpoints of rigidity, surface gloss, mechanical strength, heat resistance, shrinkage characteristics, and abrasion resistance, the polyester resin is preferably an aromatic polyester resin. In addition, 50 mol% or more (preferably 70 mol% or more) in all the dicarboxylic acid components is 50 mol% or more (preferably) in the aromatic dicarboxylic acid and / or all diol components in the above-mentioned aromatic polyester resin. Is a polyester-based resin in which 70 mol% or more is an aromatic diol. Further, an aromatic polyester-based resin which is a polymer, a copolymer, or a mixture thereof by a condensation reaction of a dicarboxylic acid containing an aromatic dicarboxylic acid and a diol containing an aliphatic diol is preferable.

  The above-mentioned aromatic polyester-based resin makes the polyester-based resin non-crystalline, thereby increasing the heat shrinkage, making it difficult to cause delamination between the surface layer and the base layer portion, and obtaining appropriate rigidity. Thus, a modified aromatic polyester resin not containing a single repeating unit but containing a modifying component (copolymer component) is preferred. As the modified aromatic polyester resin, for example, at least one of a dicarboxylic acid component and a diol component is composed of two or more components, that is, a modified aromatic polyester resin containing a modifying component in addition to the main component Resins are preferred. In other words, the aromatic polyester resin is preferably a modified aromatic polyester resin including a structural unit derived from at least two or more types of dicarboxylic acids and / or a structural unit derived from at least two or more types of diols.

  Among the above-mentioned modified aromatic polyester resins, among the above, in polyethylene terephthalate (PET) using terephthalic acid as a dicarboxylic acid component and ethylene glycol (EG) as a diol component, part of the dicarboxylic acid component and / or diol component Preferred is a modified PET in which is substituted by a modifying component (ie, another dicarboxylic acid component and / or another diol component).

  Examples of the dicarboxylic acid component used as a modifying component (copolymer component) of the modified aromatic polyester resin (particularly modified PET) include cyclohexanedicarboxylic acid, adipic acid and isophthalic acid. Among them, preferred is isophthalic acid. Moreover, as a diol component used as a modification | denaturation component, 1, 2- cyclohexane dimethanol (CHDM), 2, 2- dialkyl 1, 3- propanediols, such as neopentyl glycol (NPG), a diethylene glycol, etc. are mentioned. Among them, CHDM and 2,2-dialkyl-1,3-propanediol (especially NPG) are preferred. The alkyl group in the 2,2-dialkyl-1,3-propanediol is preferably an alkyl group having 1 to 6 carbon atoms, and the two alkyl groups may be the same or different. It may be an alkyl group.

  The above-mentioned aromatic polyester-based resin is not particularly limited, but specifically, from the viewpoint of heat-shrinkability (shrinkage property), polyethylene terephthalate (PET using PET as a dicarboxylic acid component and EG as a diol component A modified aromatic polyester resin using terephthalic acid as the dicarboxylic acid component, ethylene glycol as the diol component and CHDM as the copolymer component (sometimes referred to as "CHDM copolymer PET"); dicarboxylic acid Modified aromatic polyester resin using terephthalic acid as a component, ethylene glycol as a diol component and 2,2-dialkyl-1,3-propanediol as a copolymerization component ("2,2-dialkyl-1 , Referred to as “3-propanediol copolymerized PET” That) is preferable. In the above 2,2-dialkyl-1,3-propanediol copolymerized PET, particularly, a modified aroma using terephthalic acid as the dicarboxylic acid component, ethylene glycol as the diol component, and NPG as the copolymerization component Family polyester resins (sometimes referred to as "NPG copolymerized PET") are preferred. The aromatic polyester resin is particularly preferably CHDM copolymerized PET and / or 2,2-dialkyl-1,3-propanediol copolymerized PET, more preferably CHDM copolymerized PET and / or NPG copolymerized PET Most preferably, CHDM copolymerized PET. In addition, copolymerization components other than CHDM and 2,2-dialkyl-1,3-propanediol are used for the CHDM copolymerization PET and 2,2-dialkyl-1,3-propanediol copolymerization PET, respectively. For example, isophthalic acid or diethylene glycol may be further copolymerized.

  In the above modified aromatic polyester resin, the copolymerization ratio of the copolymerization component (modification component) [the ratio (ratio) of the copolymerized dicarboxylic acid component to the total dicarboxylic acid component, or the ratio of the copolymerized diol component to the total diol component ( The proportion) is not particularly limited, but from the viewpoint of optimizing the heat deformation behavior of the layer and reducing the delamination, 10 mol% or more (for example, 10 to 40 mol%) is preferable, more preferably 15 mol% or more (For example, 15 to 40 mol%). Among them, for example, in the case of CHDM copolymerized PET, the ratio of CHDM is preferably 10 mol% or more (EG is 90 mol% or less), more preferably 12 mol% or more (EG is 88 mol% or less And more preferably 15 mol% or more (EG is 85 mol% or less), and may be 20 mol% or more (EG is 80 mol% or less), or 25 mol% or more (EG is 75 mol% or less) . The upper limit of the CHDM ratio is preferably 40 mol% or less (EG is 60 mol% or more), more preferably 35 mol% or less (EG is 65 mol% or more), still more preferably 30 mol% of all diol components. % Or less (EG is 70 mol% or more), particularly preferably 25 mol% or less (EG is 75 mol% or more). In the case of 2,2-dialkyl-1,3-propanediol copolymerized PET, the ratio of 2,2-dialkyl-1,3-propanediol (in the case of NPG copolymerized PET, the ratio of NPG) is all 10 mol% or more (EG is 90 mol% or less) in a diol component is preferable, More preferably, it is 15 mol% or more (EG is 85 mol% or less). The upper limit of the proportion of NPG is preferably 40 mol% or less (EG is 60 mol% or more), more preferably 30 mol% or less (EG is 70 mol% or more), based on all diol components. Furthermore, part of the EG component (preferably, 1 to 30 mol%, more preferably 1 to 10 mol% in the total diol components) may be replaced with diethylene glycol.

  The aromatic polyester-based resin is preferably a substantially amorphous aromatic polyester-based resin, and more preferably an aromatic polyester-based resin that is an amorphous saturated polyester-based resin. Although not particularly limited, the aromatic polyester-based resin is difficult to be crystallized by being modified as described above, and thus can be made substantially amorphous by, for example, modification. By making the aromatic polyester resin amorphous, extrusion at a relatively low temperature becomes possible. As a result, the layer formability of the surface layer at the time of extrusion processing is improved, delamination is less likely to occur between the surface layer and the base layer portion, and the shrinkage characteristics of the shrink label are improved.

  The degree of crystallinity of the polyester-based resin measured by differential scanning calorimetry (DSC) method (measured at a temperature rising rate of 10 ° C./min) is preferably 15% or less, more preferably 10% or less. Furthermore, as the above-mentioned polyester resin, one having almost no melting point (melting peak) as determined by the above-mentioned DSC method (that is, one having a crystallinity of 0%) is most preferable. The degree of crystallization can be calculated from the value of heat of crystal fusion obtained by DSC measurement, using a clear sample of the degree of crystallinity measured by an X-ray method or the like as a standard. For heat of crystal melting, for example, using a DSC (differential scanning calorimetry) device manufactured by Seiko Instruments Inc., perform nitrogen sealing with a sample amount of 10 mg and a heating rate of 10 ° C./min, and rise once to over the melting point. The temperature can be determined from the area of the melting peak when the temperature is raised again after the temperature is lowered to room temperature. The crystallinity is preferably measured from a single resin, but when measured in the mixed state, the melting peak of the mixed resin is subtracted to obtain the melting peak of the target aromatic polyester resin. You can ask for The same applies to the degree of crystallization of the polyester resin that may be contained in the layer in the base layer portion.

  The weight average molecular weight (Mw) of the polyester resin is preferably 15,000 to 100,000, more preferably 15,000 to 90,000, and still more preferably 30,000 to 100,000 from the viewpoint of melting behavior and shrinkage behavior. 90,000, particularly preferably 30,000 to 80,000. In the case of 2,2-dialkyl-1,3-propanediol copolymerized PET, 50,000 to 70,000 are particularly preferred. In the present specification, the weight average molecular weight (Mw) is not particularly limited, but can be measured, for example, by GPC using polystyrene as a standard substance.

  The glass transition temperature (Tg) of the polyester-based resin is preferably 60 to 80 ° C., and more preferably 60 to 75 ° C., from the viewpoint of stretching characteristics and shrinkage characteristics. The Tg can be controlled by the type of dicarboxylic acid or diol constituting the polyester resin, or the copolymerization ratio of the copolymerization component (modification component) used for modification.

  In the present specification, the glass transition temperature (Tg) of a resin can be measured, for example, by DSC (differential scanning calorimetry) in accordance with JIS K 7121. Although the DSC measurement is not particularly limited, for example, it can be performed under the condition of a temperature rising rate of 10 ° C./min using a differential scanning calorimeter “DSC 6200” manufactured by Seiko Instruments Inc.

  The polyester resin may be a commercially available product, for example, “EMBRACE 21214”, “EMBRACE LV” (above, CHDM copolymer PET) manufactured by Eastman Chemical (Eastman Chemical), or Bell Polyester Products Co., Ltd. "Belpet MGG200" (2,2-dialkyl-1,3-propanediol copolymerized PET), "Belpet E02" (NPG copolymerized PET) manufactured by Bell Polyester Products Co., Ltd., and the like are commercially available.

  The polylactic acid-based polymer means a polymer having lactic acid (D-lactic acid, L-lactic acid, DL-lactic acid, or a mixture thereof) as a monomer component, and lactic acid and other monomer components (for example, And copolymers with other hydroxycarboxylic acids, lactones, dicarboxylic acids, diols, etc.). As other hydroxycarboxylic acids, for example, glycolic acid, 2-methyllactic acid, 2-hydroxybutyric acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxy-3-methylbutyric acid, 2-hydroxy-3,3-dimethylbutyric acid Butyric acid, 2-hydroxycaproic acid and the like. Examples of lactones include γ-butyrolactone, δ-valerolactone, ε-caprolactone and the like. Moreover, as dicarboxylic acid, the dicarboxylic acid etc. which were illustrated and demonstrated as a component which comprises the above-mentioned polyester-type resin, etc. are mentioned. Moreover, as a diol, the diol etc. which were illustrated and demonstrated as a component which comprises the above-mentioned polyester-type resin are mentioned. These other monomer components may be mixed in a monomer state with lactic acid and may be introduced into the polymer as a random copolymer, or an oligomer previously polymerized as a polyester, or a block copolymer with lactic acid as a prepolymer. It may be introduced into the polymer in the form of forming the polymer.

  The composition ratio of the optical isomer of lactic acid (content ratio of D-form and L-form) constituting the polylactic acid-based polymer differs depending on the required physical properties and is not particularly limited, but from the viewpoint of crystallinity control The ratio of D-lactic acid to the total lactic acid component is 1 to 20% by weight (preferably 1 to 15% by weight), or the ratio of L-lactic acid to the total lactic acid component is 1 to 20% by weight (preferably 1 to It is preferable that it is 15 weight%. Among them, the case where the ratio of D-lactic acid to the total lactic acid component is 1 to 20% by weight is more preferable.

  The proportion of lactic acid in all the monomers constituting the polylactic acid-based polymer is not particularly limited, but is preferably 50 mol% or more, more preferably 65 mol% or more, and still more preferably 80 mol% or more. Although the upper limit of the said ratio is not specifically limited, 100 mol% may be sufficient. The polylactic acid-based polymer may be used alone or in combination of two or more. For example, two or more types of polylactic acid polymers having different ratios of L-lactic acid and D-lactic acid can be used in combination.

  The polylactic acid-based polymer can be produced, for example, by polymerizing lactic acid produced using starch obtained from corn or potatoes as a raw material. The polymerization method is not particularly limited, and any known or commonly used method such as a condensation polymerization method or a ring-opening polymerization method can be adopted. For example, in the polycondensation method, polylactic acid-based polymer having an arbitrary composition can be obtained by direct dehydration condensation of lactic acid or lactic acid and other monomer components. In the ring-opening polymerization method, a polylactic acid-based polymer having an arbitrary composition can be obtained by polymerizing lactide, which is a cyclic dimer of lactic acid, in the presence of a suitable catalyst.

  The weight average molecular weight (Mw) of the polylactic acid-based polymer is not particularly limited, but is usually 5,000 to 100,000, preferably about 10,000 to 50,000, from the viewpoint of mechanical properties and melt viscosity. . When the said weight average molecular weight is too small, mechanical physical properties and heat resistance may be inferior. When the said weight average molecular weight is too large, moldability may fall.

  The content of the polyester resin in the surface layer is 50% by weight or more, preferably 55% by weight or more, more preferably 60% by weight or more, based on the total weight (100% by weight) of the surface layer. More preferably, it is 70% by weight or more, particularly preferably 80% by weight or more, and most preferably 90% by weight or more. The upper limit of the content is not particularly limited, but may be 100% by weight, or may be less than 100%, and may be 99% by weight or less and 98% by weight or less. If the content is less than 50% by weight, the heat shrinkage rate and the rigidity of the label decrease. The content of the polyester resin is the sum of the contents of all polyester resins contained in the surface layer.

  Although a surface layer is not specifically limited, You may contain resin other than the said polyester-type resin. Examples of resins other than the above-mentioned polyester resins include thermoplastic resins such as polystyrene resins, polyolefin resins, vinyl chloride resins, polycarbonate resins, polyamide resins and thermoplastic elastomers. Resin other than the said polyester-type resin may use only 1 type, and may use 2 or more types. When the surface layer contains a resin other than a polyester resin, the content of the resin is 50% by weight or less (for example, more than 0% by weight) based on the total weight (100% by weight) of the surface layer. 50% by weight or less), preferably 30% by weight or less, more preferably 10% by weight or less. The surface layer may contain a resin other than the above-mentioned polyester resin, but it is most preferable not to contain it.

  The surface layer is a lubricant, a filler, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, an antifogging agent, a flame retardant, a coloring agent, and a pinning agent, as long as the effects of the present invention are not impaired. You may contain additives, such as an alkaline earth metal), a softener, and a compatibilizer.

Density of the surface layer is not particularly limited, but is preferably 1.15~1.40g / cm ^3, more preferably 1.25~1.35g / cm ^3.

In the present specification, the density of each layer in the shrink film (the density of the surface layer, the density of the layer in the base layer portion, etc.) may be determined, for example, by actually forming a single layer and measuring the single layer. Can. Alternatively, in the case of a layer composed of a single resin, the density of the single resin may be the density of the layer. Moreover, in the case of the layer comprised from mixed resin, it can obtain | require, for example using the density and content of each resin which comprise a layer. Specifically, for example, a layer composed of a mixed resin is a resin (P1) whose density is d ₁ (g / cm ³ ) and a resin (P2) whose density is d ₂ (g / cm ³ ) When the content of P1 in the 100% by weight of the layer composed of the above mixed resin is W ₁ (% by weight) and the content of P ₂ is W ₂ (% by weight), the above mixed resin The density of the layer composed of can be determined as follows.
Density of the layer ^{(g / cm 3) = d} 1 × W 1/100 + d 2 × W 2/100

<Base layer portion>
The base layer portion in the shrink film of the present invention comprises 5 to 65 layers. Moreover, the said base layer part has a layer (A layer) which contains 50 weight% or more of polyolefin resin as a layer in a base layer part. By providing the base layer portion, the shrink label of the present invention having the shrink film of the present invention can have high rigidity. In addition, since the base layer portion has an A layer and is multilayered, the thickness per one A layer can be made relatively thin, so the shrink label of the present invention is composed of a conventional polyolefin resin The transparency is relatively higher than a shrink label having a film containing a resin layer.

  The base layer portion is not particularly limited, but includes at least one layer (B layer) containing 10 to 90% by weight of a polyolefin resin and 10 to 90% by weight of a polyester resin as a layer in the base layer portion. Is preferred. In the case where the base layer part includes the B layer in the outermost layer, the adhesion between the surface layer and the A layer in the base layer part can be improved to make it difficult to cause delamination. In addition, since the adhesiveness of the layer B is not impaired even if the layer B is interposed between the layer A and the layer A, the rigidity of the shrink label is increased by interposing the layer B in the base layer portion. It can also be used to

  In the present specification, the "base layer portion" is a portion sandwiched by the surface layer in the shrink film of the present invention. The base layer portion has a structure in which 5-65 layers are stacked, and is a layer in the base layer portion and is sandwiched between the two outermost layers located on both end faces in the thickness direction and the outermost layer It is comprised by the several intermediate | middle layer located inside thickness direction. That is, the base layer portion has a configuration of [the outermost layer / the intermediate layer /... / The intermediate layer / the outermost layer]. In addition, the above-mentioned “layer containing 50% by weight or more of polyolefin resin” may be referred to as “A layer”. In addition, the above-mentioned “layer containing 10 to 90% by weight of a polyolefin resin and 10 to 90% by weight of a polyester resin” may be referred to as “B layer”. When there are a plurality of A layers in the base layer portion, all or some of the plurality of A layers in the base layer portion may be the same layer, as defined in the present application. The layers different from each other within the range of the layer A (layers having different resin compositions and layer thicknesses constituting the layers) may be used. Similarly, when there are a plurality of B layers in the base layer portion, all or some of the plurality of B layers in the base layer portion may be the same layer, or each other. It may be different layers (layers having different resin compositions and layer thicknesses). Moreover, the said base-layer part may contain layers (other layers) other than A layer and B layer in the range which does not impair the effect of this invention. Furthermore, each of the layer A and the layer B may be the outermost layer of the base layer portion, may be an intermediate layer, or may be included in the base layer portion as both of them.

  In the base layer portion, the layers in adjacent base layer portions have different raw material compositions. When the raw material compositions of the layers in the adjacent base layer portions are the same, the interface between the adjacent layers in the base layer portion is not visible, and the layers overlap to form one layer.

  The layer in the base layer portion is a resin layer. The resin layer may contain at least a thermoplastic resin. The content of the thermoplastic resin in the resin layer is not particularly limited, but is preferably 50% by weight or more, more preferably 70% by weight or more, and still more preferably 90% by weight based on the total weight (100% by weight) of the resin layer. % Or more, particularly preferably 95% by weight or more.

  The thermoplastic resin is not particularly limited, but, for example, polyester resins, polystyrene resins, polyolefin resins, vinyl chloride resins, polycarbonate resins, polyamide resins, thermoplastic elastomers, acrylic resins, urethane resins And vinyl acetate resins.

  The layer in the base layer portion is not particularly limited, but may contain a polymer plasticizer from the viewpoint of improving the heat shrinkability of the shrink film. Examples of the polymer plasticizer include rosin resins (rosin, polymerized rosin, hydrogenated rosin and derivatives thereof, resin acid dimer, etc.), terpene resins (terpene resin, aromatic modified terpene resin, hydrogenated terpene resin) And terpene-phenol resins), petroleum resins (aliphatic petroleum resins, aromatic petroleum resins, alicyclic petroleum resins) and the like. Among them, petroleum resins are preferred. The polymer plasticizer may be used alone or in combination of two or more. As the above-mentioned polymer plasticizer, "Arcon" manufactured by Arakawa Chemical Industries, Ltd., "Clearon" manufactured by Yashara Chemical Co., Ltd., "Imarb" manufactured by Idemitsu Kosan Co., Ltd., etc. can be obtained as commercial products.

  The layer in the base layer may optionally contain other components (additives) such as a lubricant, a filler, a heat stabilizer, an antioxidant, an ultraviolet absorber, an antistatic agent, an antifogging agent, and a flame retardant. , Colorants, pinning agents (alkaline earth metals), softeners, compatibilizers, etc. may be contained. One of these components may be used alone, or two or more thereof may be used. Moreover, the layer in the said base-layer part may contain the collection | recovery raw material (reclaimed material) in the range which does not impair the effect of this invention. The recovered raw material is a recycled raw material comprising before and after commercialization, non-product parts such as film edges, remaining parts when product films are collected from intermediate products, film scraps such as non-standard products, and polymer scraps. However, the recovered raw material is preferably one (so-called self-recovered product) produced from the production of the shrink film of the present invention.

(A layer)
A layer is a layer which contains 50 weight% or more of polyolefin resin in a layer.

  The A layer contains a polyolefin resin as an essential component. The said polyolefin resin may use only 1 type, and may use 2 or more types. Moreover, although A layer is not specifically limited, You may contain resin other than the said polyolefin resin.

  The polyolefin-based resin is a polymer (including an olefin-based elastomer) composed of an olefin as an essential monomer component, that is, a polymer comprising at least a constituent unit derived from an olefin in a molecule (in one molecule). It is union. Although it does not specifically limit as said olefin, For example, alpha-olefins, such as ethylene, propylene, 1-butene, 4-methyl- 1-pentene, are mentioned.

  As said polyolefin resin, For example, the polymer (polyethylene resin) comprised as an essential monomer component ethylene, the polymer (polypropylene resin) comprised as an essential monomer component, an ionomer And amorphous cyclic olefin polymers and olefin elastomers. The polyolefin-based resin is not particularly limited, but among them, polyethylene-based resin, polypropylene-based resin, and amorphous cyclic olefin-based polymer are preferable, more preferably polyethylene-based resin and polypropylene-based resin, and still more preferably polypropylene-based resin It is. A container for carbonated beverages whose internal pressure drops and shrinks and shrinks when the polyolefin-based resin is a polyethylene-based resin, and a frozen content which shrinks and deforms due to dissolution of frozen contents It is excellent in the relaxation deterring property with respect to a container for deformation, such as a container for a container, a tube container which is dented and deformed when squeezing in order to take out contents, and is preferable. It is excellent in transparency that the said polyolefin resin is a polypropylene resin, and it is preferable. The said polyolefin resin may use only 1 type, and may use 2 or more types.

  The polyethylene resin is a polymer composed of ethylene as an essential monomer component, that is, a polymer containing at least a structural unit derived from ethylene in one molecule (one molecule). As a polyethylene resin, for example, a homopolymer of ethylene, a copolymer comprising ethylene and one or more monomer components (monomer components other than ethylene) as essential monomer components (ethylene copolymer Polymers) and the like.

  Examples of monomer components other than ethylene include α-olefins; vinyl monomers such as vinyl chloride; (meth) acrylic acid, maleic acid, fumaric acid, crotonic acid, itaconic acid, citraconic acid, 5-norbornene- Unsaturated carboxylic acids such as 2,3-dicarboxylic acid; maleic anhydride, citraconic anhydride, 5-norbornene-2,3-dicarboxylic acid anhydride, unsaturated carboxylic acids such as tetrahydrophthalic anhydride; (meth) acrylic Methyl acid, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 3- (meth) acrylate Hydroxypropyl, glycidyl (meth) acrylate, monoethyl maleate, diethyl maleate Which unsaturated carboxylic acid esters; acrylamide, methacrylamide, unsaturated amides or imides, such as maleimide; and vinyl acetate; (meth) sodium acrylate, unsaturated carboxylic acid salts such as zinc (meth) acrylate. Only 1 type may be used for monomer components other than the said ethylene, and 2 or more types may be used.

  Examples of the above-mentioned α-olefins include 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 1-decene, etc. 20 alpha-olefins (preferably C4-C8 alpha-olefins) etc. are mentioned. The above α-olefins may be used alone or in combination of two or more.

  As the ethylene copolymer, for example, a copolymer composed of ethylene and one or more α-olefins as an essential monomer component (ethylene-α-olefin copolymer); ethylene-vinyl acetate type copolymer Polymer (EVA); ethylene-carboxylic acid copolymer such as ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid copolymer (EMAA), etc .; ethylene-ethyl acrylate copolymer (EEA) And ethylene-carboxylic acid ester copolymers such as ethylene-methyl methacrylate copolymer (EMMA).

Examples of the polyethylene-based resin include low density polyethylene (LDPE), linear low density polyethylene (LLDPE) and the like, and although not particularly limited, LLDPE is particularly preferable from the viewpoint of heat shrinkability. The LDPE is a low density polyethylene of at least about 0.850 to 0.945 g / cm ³ produced by a high pressure method, containing at least a structural unit derived from ethylene. The LLDPE is a low density polyethylene of at least about 0.850 to 0.945 g / cm ³ having at least a structural unit derived from ethylene, manufactured by a medium-low pressure method, and having short chain branching.

  The content of the constituent unit derived from ethylene in the polyethylene resin (100% by weight), that is, the content of ethylene in all the monomer components (100% by weight) constituting the polyethylene resin is particularly limited. 80% by weight or more is preferable, more preferably 85% by weight or more, and still more preferably 90% by weight or more, and the upper limit thereof is 100% by weight, 99% by weight, 98% by weight, or 95% by weight May be

  Among the above-mentioned polyethylene resins, ethylene-α-olefin copolymers are preferable. The said ethylene-alpha-olefin copolymer may contain the structural unit derived from monomer components other than ethylene and alpha-olefin. Further, the content of the structural unit derived from α-olefin in the above ethylene-α-olefin copolymer (100% by weight), that is, all the monomer components constituting the above ethylene-α-olefin copolymer ( The content of the α-olefin in 100% by weight is not particularly limited, but is preferably 1 to 20% by weight, more preferably 2 to 15% by weight, and still more preferably 5 to 10% by weight. The sum of the content of structural units derived from ethylene and the content of structural units derived from α-olefin in the above ethylene-α-olefin copolymer (100% by weight), that is, the above ethylene-α-olefin copolymer The total content of ethylene and the content of α-olefin in all the monomer components (100% by weight) constituting the unit is not particularly limited, but 90% by weight or more is preferable, and more preferably 95% by weight or more More preferably, it is 97% by weight or more, particularly preferably 98% by weight or more.

The density of the polyethylene resin is not particularly limited, but is preferably 0.800 g / cm ³ or more, more preferably 0.850 g / cm ³ or more, more preferably 0.870 g / cm ³ or more, and particularly preferably 0. It is 890 g / cm ³ or more. The upper limit of the density is not particularly limited, but is preferably 0.950 g / cm ³ , more preferably 0.935 g / cm ³ . Further, the melt flow rate (MFR) (temperature 190 ° C., load 2.16 kg) of the polyethylene-based resin is not particularly limited, but it is preferably 1 to 30 g / 10 min from the viewpoint of melt extrusion suitability and productivity. Preferably, it is 1 to 10 g / 10 min.

  The polyethylene-based resin is not particularly limited, but is preferably a polyethylene-based resin (metallocene catalyst-based polyethylene-based resin) obtained by polymerization using a metallocene catalyst. As the above-mentioned metallocene catalyst, known to conventional metallocene polymerization catalysts for olefin polymerization can be used. It does not specifically limit as a polymerization method (copolymerization method) of the said polyethylene-type resin, Well-known polymerization methods, such as a slurry method, solution polymerization method, a gaseous-phase method, are mentioned.

  A commercially available product may be used as the above-mentioned polyethylene resin, for example, Ube Maruzen Polyethylene Co., Ltd. “University 4540F”, “University 3540F”, “University 2540F”, “University 1540F”, “University 0540F”, Benefits 2040 FC, 0520F, 1520F, 0520F, 715FT, Evolue SP 1520, Prime Polymer Co., Ltd., Evolue SP 2040, Kernel KF 260T, Japan Polyethylene Co., Ltd. , "Kernel KF360T", "kernel KF380", "kernel KS340T" (above, metallocene catalyst system LLDPE), Ube Maruzen Polyethylene Co., Ltd. "F234" (LDPE , Ube Maruzen Polyethylene Co., Ltd. "V206", Japan polyethylene Co., Ltd. "Novatec EVA Series" (or more, EVA) is and available in the market.

  The polypropylene-based resin is not particularly limited. For example, a homopolymer of propylene (homopolypropylene), propylene and one or more monomer components (monomer components other than propylene) are essential monomer components. And copolymers (propylene copolymers) configured as

  Examples of monomer components other than propylene include ethylene and monomer components exemplified and explained as monomer components other than ethylene in the above-mentioned ethylene copolymer. Among the above-mentioned propylene copolymers, copolymers (propylene-α-olefin copolymers) composed of propylene and one or more α-olefins as essential monomer components are preferable.

  The propylene-α-olefin copolymer is a copolymer containing at least a constituent unit derived from propylene and a constituent unit derived from an α-olefin in a molecule (in one molecule). Examples of the α-olefin used as a copolymerization component of the above-mentioned propylene-α-olefin copolymer include ethylene, 1-butene, 1-pentene, 4-methyl-1-pentene, 1-hexene and 1-heptene C4-C20 alpha olefins, such as 1-octene, 1-nonene, 1-decene, are mentioned. The above α-olefins may be used alone or in combination of two or more. The propylene copolymer (propylene-α-olefin copolymer or the like) may be a block copolymer, a random copolymer, or a graft copolymer. Among them, random copolymers and graft copolymers are preferable, and random copolymers are more preferable.

  Among the above, as the propylene-α-olefin copolymer, a propylene-ethylene copolymer is particularly preferable. In the above propylene-ethylene copolymer, the ratio of ethylene to propylene is, for example, the former / the latter (weight ratio) = 1/99 to 40/60 (preferably 2/98 to 30/70, more preferably 3/97 It is possible to select from the range of about 25/75, more preferably 3/97 to 20/80). The propylene-ethylene copolymer may be any form of block copolymer, random copolymer and graft copolymer, and ethylene and other α-olefins other than propylene may be further copolymerized. It is also good. As said propylene-ethylene copolymer, a propylene-ethylene graft copolymer and a propylene-ethylene random copolymer are preferable, and a propylene-ethylene random copolymer is more preferable. In the case of the propylene-ethylene random copolymer, the ratio of ethylene to propylene is more preferably the former / latter (weight ratio) = 3/97 to 5/95, particularly preferably 3/97 to 4.5 / 95. 5 Further, as the above-mentioned propylene-ethylene random copolymer, one having an isotactic index of 90% or more is preferable from the viewpoint of low temperature shrinkage and strength of the shrink label.

  The propylene-ethylene graft copolymer is particularly preferably a propylene-ethylene graft copolymer which is a modified polypropylene resin having a polypropylene as a main chain and a polyethylene resin graft-copolymerized. When the above-mentioned propylene-ethylene graft copolymer is used as the above-mentioned polyolefin resin, the natural shrinkage of the shrink film (or shrink label) can be suppressed, and the heat shrinkage rate at the time of shrink processing can be more effectively maintained. .

  The polypropylene-based resin is not particularly limited, but is preferably a polypropylene-based resin (metallocene catalyst-based polypropylene-based resin) obtained by polymerization using a metallocene catalyst. As the above-mentioned metallocene catalyst, known to conventional metallocene polymerization catalysts for olefin polymerization can be used. It does not specifically limit as a polymerization method (copolymerization method) of the said polypropylene resin, Well-known polymerization methods, such as a slurry method, solution polymerization method, a gaseous phase method, are mentioned.

  The propylene content in the polypropylene resin (that is, the content of the constituent unit derived from propylene in the polypropylene resin) is not particularly limited, but from the viewpoint of the heat shrinkability, the strength and the density of the shrink film, the polypropylene resin 50 weight% or more is preferable with respect to the total weight (100 weight%) of resin, More preferably, it is 70 weight% or more, More preferably, it is 80 weight% or more. The upper limit of the propylene content may be 100% by weight.

  Further, the content of the structural unit derived from α-olefin in the above-mentioned propylene-α-olefin copolymer (100% by weight), that is, all the monomer components constituting the above-mentioned propylene-α-olefin copolymer ( The content of α-olefin in 100% by weight is not particularly limited, but is preferably 1 to 40% by weight, more preferably 2 to 30% by weight, and still more preferably 3 to 25% by weight. The sum of the content of constituent units derived from propylene and the content of constituent units derived from α-olefin in the above-mentioned propylene-α-olefin copolymer (100% by weight), ie, the above-mentioned propylene-α-olefin copolymer The total of the content of propylene and the content of α-olefin in all the monomer components (100% by weight) constituting the unit is not particularly limited, but is preferably 90% by weight or more, more preferably 95% by weight or more More preferably, it is 97% by weight or more, particularly preferably 98% by weight or more.

Although the density of the said polypropylene resin is not specifically limited, 0.800 g / cm < ³ > or more is preferable, More preferably, it is 0.850 g / cm < ³ > or more. The upper limit of the density is not particularly limited, but is preferably 0.950 g / cm ³ .

  Commercial products may be used as the polypropylene-based resin, and “Wintec WFX6”, “Wintech WFX4”, “Wintec WFX4T”, “Wintech WFX4TA”, “Wintech WFW4” manufactured by Nippon Polypropylene Corporation may be used. , "Wintec WFW 4F", "Wintech WFW 5T", "Wintech 1987 FC" (above, metallocene catalyst type propylene-ethylene random copolymer), Mitsubishi Chemical Co., Ltd. "Zelas # 7000", "Zelas # 5000" “Novatec FB3HAT”, “Novatec FW3GT”, “Novatec FW4BT”, “Novatec FX4E”, “Novatec FX4G” (above, polypropylene-based resin) manufactured by Nippon Polypropylene Corp., “Vistamaxx” manufactured by Exxon Mobil Chemical Co., Ltd. 3020FL "," Vistamaxx 3980FL "," Vistamaxx 6102 "(or more, propylene-ethylene graft copolymer) are commercially available.

  As the non-crystalline cyclic olefin polymer, for example, a copolymer of an α-olefin such as ethylene, propylene, 1-butene, 1-hexene, 4-methyl-1-pentene and at least one cyclic olefin (Sometimes referred to as "cyclic olefin copolymer"), ring-opened polymer of cyclic olefin or hydrogenated product thereof (sometimes referred to as "ring-opened polymer of cyclic olefin or hydrogenated product thereof") Can be mentioned. The cyclic olefin copolymer, the ring-opening polymer of cyclic olefin or the hydrogenated product thereof also includes the graft modified product thereof.

Examples of cyclic olefins used for the above-mentioned amorphous cyclic olefin polymers include bicyclo [2.2.1] hept-2-ene (norbornene) and tetracyclo [4.4.0.1 ^2,5 . 1 ^{7, 10} ] -3-dodecene, hexacyclo [6.6.1.1 ^3,6 . 1 ^{10, 13} . 0 ^{2, 7} . 0 ^{9, 14} ] -4-heptadecene, octacyclo [8.8.0.1 ^2,9 . 1 ^{4, 7} . ^{11, 18} . ^{13, 16} . 0 ^{3, 8} . 0 ^{12, 17} ] -5-docosene, pentacyclo [6.6.1.1 ^3,6 . 0 ^{2, 7} . 0 ^9,14] -4-hexadecene, heptacyclo-5-icosene, heptacyclo-5-henicosenoic, tricyclo [4.3.0.1 ^{2, 5]-3-decene,} tricyclo [4.4.0.1 ^{2 , 5} ] -3-Undecene, pentacyclo [6.5.1.1 ^3,6 . 0 ^{2, 7} . 0 ^{9, 13} ] -4-pentadecene, pentacyclopentadecadiene, pentacyclo [4.7.0.1 ^2,5 . 0 ^{8, 13} . 19, ¹² ] -3-Pentadecene, nonacyclo [9.10.1.1 ^4,7 . ^{13, 20} . ^{15, 18} . 0 ^{2, 10} . 0 ^{12, 21} . 0 ^14,19] -5-polycyclic olefins such pentacosenoic like. Among them, norbornene is preferred. These cyclic olefins may have an ester group such as a methoxycarbonyl group or an ethoxycarbonyl group, an alkyl group such as a methyl group, a substituent such as a haloalkyl group, a cyano group or a halogen atom in the ring.

  The cyclic olefin copolymer is, for example, a so-called Ziegler catalyst, a metallocene catalyst, or the like in a hydrocarbon solvent such as hexane, heptane, octane, cyclohexane, benzene, toluene, xylene, etc. It can be obtained by polymerization using a catalyst. Such cyclic olefin copolymers are commercially available, and for example, "APEL" manufactured by Mitsui Chemicals, Inc., "TOPAS" manufactured by Polyplastics Co., Ltd., etc. can be used.

  The ring-opened polymer of cyclic olefin or hydrogenated product thereof is, for example, subjected to metathesis polymerization (ring-opening polymerization) catalyzed by one or more cyclic olefins catalyzed by a molybdenum compound or a tungsten compound, It can be produced by further hydrogenating the obtained polymer. Such ring-opened polymers of cyclic olefins or hydrogenated products thereof are commercially available. For example, “Arton” manufactured by JSR Co., Ltd., “Zeonex”, “Zeonor” manufactured by Nippon Zeon Co., Ltd., etc. can be used.

  The non-crystalline cyclic olefin polymer is not particularly limited, but a cyclic olefin copolymer is more preferable. When a cyclic olefin copolymer is mixed with a polyolefin-based resin, it is possible to obtain a shrink film having high compatibility and compatibility with the polyolefin-based resin, and excellent transparency and impact resistance.

  The glass transition temperature (Tg) of the non-crystalline cyclic olefin polymer is not particularly limited, but is preferably 50 to 80 ° C., more preferably 60 to 80 ° C., still more preferably 60 to 75, from the viewpoint of stretching properties. ° C., most preferably 65-75 ° C. (especially around 70 ° C.). The glass transition temperature of the amorphous cyclic olefin polymer can be adjusted by the kind of the monomer component (for example, cyclic olefin etc.) and the blending ratio thereof.

  When the non-crystalline cyclic olefin polymer is a cyclic olefin copolymer, the content of the structural unit derived from cyclic olefin (eg, norbornene etc.) in the cyclic olefin copolymer is not particularly limited, but heat is preferable. From the viewpoint of shrinkage, it is preferably 50 to 75% by weight, more preferably 60 to 70% by weight, based on the total weight (100% by weight) of the cyclic olefin copolymer. For example, it is preferable that the norbornene content (Norbornene content in COC) in the cyclic olefin copolymer is in the above range.

  A commercial item may be used as said olefin type elastomer, Mitsubishi Chemical Co., Ltd. product, "Zelas" etc. are commercially available.

  Among the above polyolefin resins, ethylene homopolymers, ethylene-α-olefin copolymers, propylene homopolymers and propylene-α-olefin copolymers are preferable, and propylene homopolymers and propylene-α-olefin copolymers Merging is more preferable, and metallocene catalyst-based polypropylene homopolymer, metallocene catalyst-based propylene-α-olefin copolymer (particularly, metallocene catalyst-based propylene-α-olefin random copolymer is preferable, and among them, metallocene catalyst-based propylene-ethylene Random copolymers are more preferred.

  The content of the polyolefin resin in the layer A is 50% by weight or more, preferably 55% by weight or more, and more preferably 60% by weight or more based on the total weight (100% by weight) of the layer A. The upper limit of the content may be 100% by weight. In addition, when 2 or more types of polyolefin resin are contained in A layer, said "content of polyolefin resin in A layer" is the content of all the polyolefin resin contained in A layer. It is a total.

  Although A layer is not specifically limited, You may contain resin other than the said polyolefin resin. Examples of resins other than the above-mentioned polyolefin-based resins include thermoplastic resins such as polyester-based resins, polystyrene-based resins, vinyl chloride-based resins, polycarbonate-based resins, polyamide-based resins, and thermoplastic elastomers. When the layer A contains a resin other than the above-mentioned polyolefin resin, from the viewpoint of improving the adhesion between the base layer portion and the surface layer, among them, the thermal contraction rate and the rigidity, and when the layer A has the outermost layer of the base layer portion, Polyester resins are preferred. Resin other than the said polyolefin resin may use only 1 type, and may use 2 or more types.

  When the layer A contains a resin other than a polyolefin resin, the content of the resin other than the polyolefin resin is 50% by weight or less (e.g., 0%) based on the total weight (100% by weight) of the layer A. It is more than 50% by weight, preferably 1 to 45% by weight, and more preferably 5 to 40% by weight. When the layer A contains a resin other than a polyolefin resin, the upper limit of the content of the polyolefin resin in the layer A may be less than 100% by weight, and preferably 99% by weight or less. Preferably it is 95 weight% or less.

  When the layer A contains a polyester-based resin, the content of the polyester-based resin in the layer A is preferably 5% by weight or more based on the total weight (100% by weight) of the layer A, and is more preferable. Is 10% by weight or more. The upper limit of the content is not particularly limited, but is preferably less than 50% by weight, more preferably 40% by weight or less, and still more preferably 30% by weight or less. In addition, when A layer contains 10 weight% or more of polyester-type resin, said A layer corresponds also to B layer mentioned later. In this case, the base layer portion is a base layer portion having at least an A layer as a layer, and is also a base layer portion having at least a B layer as a layer.

  Although it does not specifically limit as said polyester-based resin, For example, the polyester-based resin etc. which were illustrated and demonstrated as polyester-based resin contained in the above-mentioned surface layer are mentioned. The polyester resin may be the same polyester resin as the polyester resin contained in the surface layer, or may be a different polyester resin. Further, from the viewpoint of recyclability, since a polyester resin contained in the surface layer can be used as a recovered raw material, a polyester resin identical to the polyester resin contained in the surface layer is preferable.

  The content of the polymer plasticizer (particularly petroleum resin) in the layer A in the case of adding the polymer plasticizer is not particularly limited, but it is preferably 2 to 2 based on the total weight (100% by weight) of the layer A. 35 wt% is preferred, more preferably 4 to 25 wt%. The effect of a polymer plasticizer can fully be acquired as the said content is 2 weight% or more. When the content is more than 35% by weight, the shrink film may become brittle.

  The layer A may contain a recovered raw material (reclaimed material) as long as the effects of the present invention are not impaired. The content of the recovered raw material in the layer A in that case is preferably 1 to 50% by weight with respect to the total weight (100% by weight) of the layer A from the viewpoint of recyclability.

Although the density of the A layer is not particularly limited, it is preferably 0.850 to 1.000 g / cm ³ , more preferably 0.870 to 0.970 g / cm ³ .

(B layer)
The layer B is a resin layer containing 10 to 90% by weight of a polyolefin resin and 10 to 90% by weight or more of a polyester resin in the layer. It is preferable to have a B layer as the outermost layer of the base layer portion, because the adhesiveness between the surface layer and the A layer in the base layer portion can be improved, and delamination can be less likely to occur. Further, since the adhesiveness is not impaired even if the B layer is interposed between the A layer and the A layer, the rigidity of the shrink label is increased by interposing the B layer in the base layer portion between the A layers. Can also be used. In addition, said B layer is said A layer, when content of the polyolefin resin in a layer is 50 weight% or more.

  The layer B contains a polyolefin resin and a polyester resin as essential components. The said polyolefin resin and polyester resin may use only 1 type, and may use 2 or more types. The B layer is not particularly limited, but may contain a resin other than the above-mentioned polyolefin resin and polyester resin.

  Although it does not specifically limit as polyolefin resin contained in said B layer, The polyolefin resin etc. which were illustrated and demonstrated as polyolefin resin contained in the above-mentioned A layer, etc. are mentioned. The polyolefin resin may be the same polyolefin resin as the polyolefin resin contained in the layer A, or may be a different polyolefin resin.

  Among the above polyolefin resins, ethylene homopolymers, ethylene-α-olefin copolymers, propylene homopolymers and propylene-α-olefin copolymers are preferable, and propylene homopolymers and propylene-α-olefin copolymers Merging is more preferable, and metallocene catalyst-based polypropylene homopolymer, metallocene catalyst-based propylene-α-olefin copolymer (particularly, metallocene catalyst-based propylene-α-olefin random copolymer is preferable, and among them, metallocene catalyst-based propylene-ethylene Random copolymers are more preferred.

  Although it does not specifically limit as a polyester-type resin contained in said B layer, The polyester-type resin etc. which were illustrated and demonstrated as a polyester-type resin contained in the above-mentioned surface layer are mentioned. The polyester resin may be the same polyester resin as the polyester resin contained in the surface layer, or may be a different polyester resin. From the viewpoint of recyclability, since a polyester resin contained in the surface layer can be used as a recovered raw material, a polyester resin identical to the polyester resin contained in the surface layer is preferable.

  Among the above polyester resins, modified aromatic polyester resins are preferable, substantially non-crystalline aromatic polyester resins are more preferable, and aromatic polyester resins that are non-crystalline saturated polyester resins are preferable. More preferable. Among the above modified aromatic polyester resins, CHDM copolymerized PET and 2,2-dialkyl-1,3-propanediol copolymerized PET (particularly NPG copolymerized PET) are preferable, and CHDM copolymerized PET is more preferable. It is.

  The content of the polyolefin resin in the layer B is 10 to 90% by weight with respect to the total weight (100% by weight) of the layer B, preferably 15 to 85% by weight, more preferably 20 to 80%. %. When the content is 10% by weight or more, the adhesiveness with the layer A is improved when the layer B is adjacent to the layer A, which is preferable.

  The content of the polyester-based resin in the layer B is 10 to 90% by weight, preferably 15 to 85% by weight, more preferably 20 to 80% by weight based on the total weight (100% by weight) of the layer B. %. When the content is 10% by weight or more, the adhesion between the base layer portion and the surface layer is improved when the B layer is the outermost layer of the base layer portion, which is preferable.

  The total content of the polyolefin-based resin and the polyester-based resin in the layer B is 20% by weight or more based on the total weight (100% by weight) of the layer B, preferably 50% by weight or more, more preferably It is 60% by weight or more, more preferably 75% by weight or more. The upper limit of the total content is 100% by weight.

  In order to further increase the rigidity of the shrink label, a layer containing 10 to 60% by weight of a polyolefin resin and 40 to 90% by weight of a polyester resin is preferable as the B layer, and 10 to 50 of a polyolefin resin is preferable. The layer containing 50% to 90% by weight of polyester resin is more preferable.

  Among them, a layer containing 40 to 90% by weight of a polyolefin-based resin and 10 to 60% by weight of a polyester-based resin is preferable as the layer B when a shrink label is desired to have a lower density. A layer containing 90% by weight and 10 to 50% by weight of a polyester resin is more preferable, and a layer containing 55 to 90% by weight of a polyolefin resin and 10 to 45% by weight a polyester resin is more preferable.

  Although B layer is not specifically limited, You may contain resin other than the said polyolefin resin and the said polyester resin. Examples of such resins include thermoplastic resins such as polystyrene resins, vinyl chloride resins, polycarbonate resins, polyamide resins and thermoplastic elastomers. The resins other than the above-mentioned polyolefin resin and polyester resin may be used alone or in combination of two or more. When the layer B contains a resin other than the polyolefin resin and the polyester resin, the content of the resin is 80% by weight or less (for example, 0% by weight) based on the total weight (100% by weight) of the layer B. % To 80% by weight or less), preferably 5 to 50% by weight, more preferably 15 to 40% by weight.

  The content of the polymer plasticizer (particularly petroleum resin) in the layer B in the case of adding the polymer plasticizer is not particularly limited, but it is preferably 2 to 2 based on the total weight (100% by weight) of the layer B. 25 weight% is preferable, and 4 to 20 weight% is more preferable. The effect of a polymer plasticizer can fully be acquired as the said content is 2 weight% or more. When the content exceeds 25% by weight, the shrink film may become brittle.

  The layer B may contain a recovered raw material (reclaimed material) as long as the effects of the present invention are not impaired. In that case, the content of the recovered raw material in the layer B is preferably 1 to 80% by weight with respect to the total weight (100% by weight) of the layer B.

The density of the layer B is not particularly limited, but is preferably 0.870 to 1.150 g / cm ³ , and more preferably 0.870 to 1.050 g / cm ³ from the viewpoint of low specific gravity.

(The outermost layer)
The said outermost layer is a layer of a base layer part, Comprising: It is a layer located in the both end surfaces of the thickness direction. The outermost layer may be the layer A or the layer B, or may be a layer other than the layer A and the layer B. The outermost layer is not particularly limited, but a resin layer containing, as an essential component, at least one resin selected from the group consisting of EVA, modified polystyrene resins, styrene elastomers, polyester elastomers, and olefin elastomers; The B layer is preferred, and the B layer is particularly preferred. When the outermost layer of the base layer portion is the B layer, the shrink label can maintain higher relaxation suppressing property, heat shrinkability, and rigidity in addition to the improvement in the interlayer strength between the surface layer and the base layer portion. ,preferable. In the present specification, the above-mentioned “at least one resin selected from the group consisting of EVA, modified polystyrene resin, styrene elastomer, polyester elastomer, and olefin elastomer” is referred to as “specific resin”. There is. In addition, the above “resin layer containing, as an essential component, at least one resin selected from the group consisting of EVA, modified polystyrene resin, styrene elastomer, polyester elastomer, and olefin elastomer”, ie “specific resin” The resin layer contained as an essential component may be called a "specific resin layer."

  When the outermost layer is the specific resin layer, the content of the specific resin in the specific resin layer is not particularly limited, but 50% by weight based on the total weight (100% by weight) of the specific resin layer. The above is preferable, More preferably, it is 70 weight% or more, More preferably, it is 75 weight% or more. The upper limit of the content is not particularly limited, and may be 100% by weight. When the said specific resin layer contains 2 or more types of said specific resin, content of the said specific resin is the sum total of content of all the specific resin in the said specific resin layer.

(Intermediate layer)
The intermediate layer is a layer constituting the base layer portion, and is a layer other than the outermost layer. The base layer portion is not particularly limited, but a layer or the like for giving various functions of the base layer portion can be used as the intermediate layer, and, for example, an intermediate layer other than the A layer, B layer, A layer and B layer Layers (other intermediate layers) can be mentioned. The base layer portion preferably includes at least an A layer as the intermediate layer, and more preferably includes at least an A layer and a B layer.

  Examples of the other intermediate layer include layers other than the layer A and the layer B among the layers illustrated and described as the layer in the base layer portion described above. Among them, the specific resin layer described as the outermost layer described above is preferable.

  When there are a plurality of other intermediate layers in the base layer portion, all or some of the plurality of other intermediate layers in the base layer portion may be the same layer, The layers may be different layers (layers having different resin compositions and layer thicknesses).

(Layer configuration of base layer, physical properties, etc.)
The number of layers included in the base layer portion is 5 to 65, preferably 5 to 33, and more preferably 9 to 33. If the number of layers is less than 5, the effect of multilayering the base layer portion is small, and the effect of improving the rigidity can not be obtained. On the other hand, when the number of layers exceeds 65, when the thickness (total thickness) of the shrink film is in the range suitable for the shrink label, the thickness of the layer A (thickness per layer) becomes too thin. The effect of using a layer is reduced, the stiffness of the shrink film and the shrink label is reduced, and the waist is weakened.

  The base layer portion contains one or more layers, preferably two or more layers, and more preferably three or more layers as a layer in the base layer portion. The upper limit of the number of layers A is not particularly limited, but may be 65 or less, preferably 33 or less, and more preferably 17 or less.

  When the base layer portion has a B layer, the number of B layers in the base layer portion is one or more, preferably two or more, and more preferably four or more. The upper limit of the number of layers B is not particularly limited, but may be 64 or less, preferably 33 or less, and more preferably 17 or less. When the layer B is also an layer A, the upper limit of the number of layers B may be 65 layers.

  When the base layer portion has a layer B, the total number of layers A and B is not particularly limited, but preferably 5 to 65, more preferably 5 to 33, and still more preferably 9 to 33. is there.

  When the said base layer part has B layer, it is preferable that the said base layer part has a laminated structure which A layer and B layer adjoin. When the base layer portion has the above-described laminated structure, the layer A has no problem in adhesion to the layer B, and can be used to optimize the shrinkage rate or to increase the compressive strength and rigidity of the shrink label. Therefore, it is preferable.

  The base layer portion is not particularly limited, but it is preferable that the base layer portion have three or more interfaces formed by the A layer and the B layer being adjacent (directly laminated). The number of the interfaces is not particularly limited, but is preferably 3 or more, more preferably 4 or more, and still more preferably 5 or more. Further, the upper limit of the number of the interfaces is 64, preferably 32. It is preferable that the base layer portion has three or more of the above interfaces because the tearability of the label is improved, and the stress due to the impact of the drop is dispersed and relaxed at each interface when dropped and the drop resistance is also improved. Further, since the base layer portion is multilayered, the label is difficult to delaminate (delamination) even when the interlayer strength at the interface is relatively weak.

  When the base layer part has a B layer, the layer A is not particularly limited in the base layer part, but it is preferable to be interposed between two or more B layers, and it is preferable to be interposed between all B layers in the base layer part. Is more preferable. In particular, in the base layer portion, the A layer and the B layer are not particularly limited, but are preferably stacked alternately, and more preferably directly stacked alternately without interposing another layer. That is, it is most preferable that the above-mentioned base layer part contains 5 to 65 layers in total alternately as A layer and B layer as a layer.

  The base layer portion may include 5 to 65 layers, and at least the A layer as a layer in the base layer portion. The laminated constitution of the above-mentioned base layer part is not particularly limited, but specifically, laminated constitution which repeats “A layer / B layer” as a repeating unit without interposing layers other than A layer and B layer (A layer / B Layer / A layer / B layer / ... ... / A layer / B layer / A layer), (B layer / A layer / B layer / A layer / ... ... / B layer / A layer / B layer) , (A layer / B layer / A layer / B layer / ... ... / A layer / B layer) or (B layer / A layer / B layer / A layer / ... ... / B layer / A layer) It is preferable that The outermost layer on both sides of the base layer portion may be an A layer or a B layer, but a B layer is preferable on both sides. It is preferable to use a B layer as the outermost layer of the base layer portion, since it is possible to suppress delamination which is likely to occur during shrinking (at the time of heat contraction) between the surface layer and the base layer portion. Moreover, since the stress at the time of thermal contraction becomes small and the layers are not easily displaced, the rigidity can be further increased without decreasing the interlayer strength, which is preferable.

  Although not particularly limited, in the base layer portion, all the layers A are preferably formed of the same raw material, and all the layers B are preferably formed of the same raw material. That is, the layers A and the layers B are preferably formed of the same raw material. In particular, all of the layers A are preferably layers of the same composition, and all layers B are preferably layers of the same composition.

  When the base layer portion has a laminated structure in which the A layer and the B layer are adjacent, as in the laminated structure repeating the above “A layer / B layer” as a repeating unit, the A layer and the B layer have different raw material compositions. It is a layer, and the content of the polyolefin resin in each layer is preferably different, and the difference in the content of the polyolefin resin in each layer is more preferably 5% by weight or more, and 8% More preferably, it is at least%.

  In addition, as a lamination constitution of the above-mentioned base layer part, for example, it consists of A layer and other layers, and laminates constitution which repeats "A layer / other layers" as a repeating unit (A layer / other layer / A layer / other Layer / ... / A layer / other layer / A layer), (other layer / A layer / other layer / other layer / A layer / ... ... other layer / A layer / other layer), (A layer / other layer / A layer / other layer / ... ... / A layer / other layer) or (other layer / A layer / other layer / A layer / ... ... other Layer / A layer). The outermost layers on both sides of the base layer portion may be an A layer or other layers.

  In addition, the laminated constitution of the base layer part in the case where the base layer part is formed of only the A layer is, for example, using two A layers (A1 layer and A2 layer) having different raw material compositions “A1 layer / A2 Layer structure (A1 layer / A2 layer / A1 layer / A2 layer / ..... / A1 layer / A2 layer / A1 layer) repeating as a repeating unit, (A2 layer / A1 layer / A2 layer / A1 layer / A1 layer) ... / A2 layer / A1 layer / A2 layer), (A1 layer / A2 layer / A1 layer / A2 layer / ... ... / A1 layer / A2 layer) or (A2 layer / A1 layer / A2 layer / A1 layer /...../ A2 layer / A1 layer) can be mentioned. The outermost layers on both sides of the base layer portion may be an A1 layer or an A2 layer.

  When the base layer portion has a laminated structure in which two A layers having different raw material compositions are adjacent, as in the laminated structure repeating the above “A1 layer / A2 layer” as a repeating unit, the adjacent two A layers are raw materials The layers preferably have different compositions, and the content of the polyolefin resin in each layer is preferably different, and the difference in the content of the polyolefin resin in each layer is 5% by weight or more. Preferably, it is 8% by weight or more.

  In addition, as the laminated configuration of the base layer portion, for example, the outermost layers on both sides are the specific resin layer, and the intermediate layer is “A layer / B layer”, “A layer / other layer”, or “A1 layer / The laminated structure which makes it the structure repeated as an A2 layer "as a repeating unit is mentioned. In such a laminated structure, specifically, when the intermediate layer is configured to be repeated with "A layer / B layer" as a repeating unit (specific resin layer / A layer / B layer / A layer / B layer) / · · · / A layer / B layer / A layer / specific resin layer), (specific resin layer / B layer / A layer / B layer / A layer / · · · · / B layer / A layer / B layer / Specific resin layer), (Specific resin layer / A layer / B layer / A layer / B layer / ···· / A layer / B layer / Specific resin layer) or (Specific resin layer / B layer / A layer / B-layer / A-layer /... / B-layer / A-layer / specific resin layer) can be mentioned. When the intermediate layer is configured to be repeated as “A layer / other layer” as a repeating unit (specific resin layer / A layer / other layer / A layer / other layer /... / A layer / others Layer / A layer / specific resin layer), (specific resin layer / other layer / A layer / other layer / other layer / A layer / ... ... / other layer / A layer / other layer / specific resin layer) , (Specific resin layer / A layer / other layer / A layer / other layer / ... ... / A layer / other layer / specific resin layer) or (specific resin layer / other layer / A layer / other Layer / A layer /... / Other layer / A layer / specific resin layer). When the intermediate layer is configured to be repeated with “A1 layer / A2 layer” as a repeating unit (specific resin layer / A1 layer / A2 layer / A1 layer / A2 layer /... / A1 layer / A2 layer / A1 Layer / specific resin layer), (specific resin layer / A2 layer / A1 layer / A2 layer / A1 layer / ... ... / A2 layer / A1 layer / A2 layer / specific resin layer), (specific resin layer / A1 layer / A2 layer / A1 layer / A2 layer / ... ... / A1 layer / A2 layer / specific resin layer) or (specific resin layer / A2 layer / A1 layer / A1 layer / A1 layer / A1 layer / ... ... / A2 layer / A1 layer / specific resin layer).

Among the above, from the viewpoint of forming the interface between each layer in the base layer portion as the base layer portion to further improve the rigidity of the shrink film or the label and to make the density low, the following (I) to (III) It is particularly preferable that the base layer portion satisfy at least one of them. (I) all layers in the base layer part are A layers, and each A layer in the base layer part is a base layer part different in density from the adjacent A layer; (II) all in the base layer part A layer is an A layer, and a base layer portion alternately containing a layer containing 50% by weight or more of a polyethylene resin and a layer containing 50% by weight or more of a polypropylene resin as the A layer; (III) A layer , base portion having at least a layer containing a density 0.900 g / cm ³ or less polyethylene resin and 0.900 g / cm ³ by summing the following polypropylene resin 50% by weight or more. In addition, the said base-layer part may satisfy | fill only one of said (I)-(III), and may satisfy | fill two or more.

  As the base layer portion satisfying the above (I), for example, the base layer portion is a base layer portion in which two A layers (A1 layer and A2 layer) having different densities are directly laminated alternately without interposing other layers. Can be mentioned. In this case, as a combination of the A1 layer and the A2 layer, for example, (i) A1 layer and A2 layer respectively containing polypropylene resins different in density; (ii) A1 respectively containing polyethylene resins different in density Layer and A2 layer; (iii) A1 layer containing 50% by weight or more of polyethylene resin and A2 layer containing 50% by weight or more of polypropylene resin; (iv) at least one of A1 layer and A2 layer of polyolefin resin As a mixed resin layer of a resin and another resin, an A1 layer and an A2 layer, etc. in which the content of the polyolefin resin and the other resin are different from each other can be mentioned. Among the above, the base layer portion satisfying the above (I) is preferably the above (iv) from the viewpoint of heat shrinkability.

In base unit satisfying the (I), the difference in density of the A layer adjacent to is not particularly limited, but is preferably 0.005 g / cm ³ or more, more preferably 0.01 g / cm ³ or more, more preferably It is 0.02 g / cm ³ or more. It is thought that the interface between two adjacent A layers is clearly formed when laminating by coextrusion or the like if the difference in density is 0.005 g / cm ³ or more, but rigidity improvement by multilayer lamination is considered. It is preferable because the effect of is easily obtained.

(Structure, physical properties, etc. of the shrink film of the present invention)
The shrink film of the present invention includes the base layer portion and the surface layer. The surface layer is laminated on both sides of the base layer portion, and provided on one surface side and the other surface side of the base layer portion.

  The thickness (total thickness) of the shrink film of the present invention is not particularly limited, but is preferably 10 to 100 μm, more preferably 15 to 50 μm, and still more preferably 20 to 45 μm. When the thickness is 10 μm or more, the rigidity is further improved and the waist becomes stronger, which is preferable.

  The thickness of the surface layer (the thickness of one layer) is not particularly limited, but is preferably 1 to 15 μm, more preferably 2 to 10 μm, still more preferably 2.5 to 8 μm, and particularly preferably 5 to 8 μm. The rigidity of a label improves more that the said thickness is 1 micrometer or more, and is preferable. It becomes difficult to generate | occur | produce delamination between a surface layer and a base layer part as the said thickness is 15 micrometers or less, and it is preferable. In the shrink film of the present invention, the thicknesses of the surface layers on both sides of the base layer may be the same or different from each other.

  The thickness of the base layer is not particularly limited, but is preferably 5 μm or more, more preferably 8 to 90 μm, still more preferably 10 to 45 μm, and particularly preferably 11 to 40 μm. The rigidity of a label improves more that the said thickness is 5 micrometers or more, and is preferable. It is preferable that the thickness is 90 μm or less, since delamination is difficult even when the delamination strength of the interface between the layers in the base layer portion is relatively low.

  The thickness of the layer in the base layer (the thickness of one layer) is not particularly limited, but is preferably 0.2 μm or more (eg, 0.2 to 15 μm), more preferably 0.3 μm or more (eg, 0.3) ̃10 μm). When the thickness is 0.2 μm or more, the effect of improving the rigidity of the shrink label can be sufficiently obtained, which is preferable. The thickness of the plurality of layers in the base layer portion may be the same as or different from all of them.

  The thickness (thickness per layer) of the outermost layer of the base layer portion is not particularly limited, but is preferably 0.2 μm or more (eg, 0.2 to 15 μm), and more preferably 0.3 to 10 μm.

  The thickness (thickness per layer) of the intermediate layer is not particularly limited, but is preferably 0.3 μm or more (for example, 0.3 to 15 μm), and more preferably 0.6 to 10 μm.

  The thickness (thickness per layer) of the layer A is not particularly limited, but is preferably 0.2 μm or more, more preferably 0.3 μm or more, and further preferably 0.6 μm or more. When the thickness is 0.2 μm or more, the effect of improving the rigidity is large, and delamination between the surface layer and the base layer is unlikely to occur, which is preferable. The upper limit of the thickness is not particularly limited, but is preferably 15 μm, more preferably 10 μm, and still more preferably 8 μm. When the base layer portion includes a plurality of layer A, the thickness of the plurality of layers A in the base layer portion may be the same as or different from each other. For example, the A layer, which is the outermost layer of the base layer portion, may be thinner than the A layer, which is an intermediate layer of the base layer portion.

  When the base layer portion includes the B layer, the thickness (thickness per layer) of the B layer is not particularly limited, but is preferably 0.2 μm or more (eg, 0.2 to 15 μm), more preferably 0.3 It is preferably 10 to 10 μm, more preferably 0.4 to 5 μm. When the thickness is 0.2 μm or more, the effect of improving the rigidity of the shrink label can be sufficiently obtained, which is preferable. When the base layer portion includes a plurality of B layers, the thickness of the plurality of B layers in the base layer portion may be the same as or different from each other. For example, the B layer which is the outermost layer of the base layer portion may be thinner than the B layer which is an intermediate layer of the base layer portion. In addition, the thickness of the layer B is preferably thinner than the thickness of the layer A from the viewpoint of transparency.

  The ratio [(thickness of surface layer) :( thickness of base layer)] of the thickness of the surface layer (sum of the thicknesses of all surface layers) and the thickness of the base layer in the shrink film of the present invention is not particularly limited. 2: 1 to 1:10 are preferable, more preferably 1: 1 to 1: 4. When the base layer portion is thicker than the above ratio of 2: 1, wrinkles and delamination between the surface layer and the base layer portion are less likely to occur, which is preferable. On the other hand, when the surface layer is thicker than 1:10, the rigidity and abrasion resistance of the label are further improved, which is preferable.

  The shrinkage stress at 90 ° C. of the shrink film of the present invention is not particularly limited, but is preferably 1 to 10 N, more preferably 1 to 7 N, still more preferably 1 to 5 N, and particularly preferably 1 to 3 N. It is preferable that the contraction stress is 1 N or more, since the followability of the shrink label to the container and the like is improved. The shrinkage stress can be adjusted, for example, by the thickness of the shrink film, the layer configuration, the raw material composition, the raw material composition of the surface layer, the layer in the base layer portion, the thickness, and the like. In the present specification, the contraction stress is measured with a measurement width of 15 mm.

  The shrinkage stress at 90 ° C. of the shrink film of the present invention is not particularly limited. For example, both ends of the shrink film are fixed so that the shrink film does not sag, and the film is dipped in warm water at 90 ° C. Can be obtained by measuring the stress at which the heat shrinks. Although the measuring machine used for the measurement of the said contraction stress is not specifically limited, For example, Shimadzu Corp. make "Shimadzu autograph (AGS-50G: load cell type 500N)" etc. are mentioned.

  The shrink film of the present invention is a film oriented in at least one direction (for example, a film oriented in one direction, a film oriented in one direction and a direction different from one direction) from the viewpoint of exhibiting a shrink property preferable. Furthermore, it is preferable that all the film layers (surface layer, each layer of the base layer part including the A layer) be a film in which at least one direction is oriented. In particular, a film oriented in one direction (uniaxially oriented film) or a film oriented in one direction and a direction orthogonal to one direction (biaxially oriented film) is often used as a shrink film, and in particular, uniaxial orientation Films are generally used, including substantially unidirectionally stretched films that are primarily stretched in one direction and slightly stretched in a direction orthogonal to the one direction.

  The film oriented in at least one direction is obtained by stretching the unstretched film in at least one direction. For example, when the film oriented in at least one direction is a uniaxially oriented film, it is obtained by stretching the unstretched film in one direction, and when it is a biaxially oriented film, the unstretched film is unidirectionally It is obtained by stretching in the direction orthogonal to the direction. The shrink label of the present invention can be thermally shrunk mainly in the direction of orientation of the shrink film of the present invention.

  The heat shrinkage ratio (sometimes referred to as “heat shrinkage ratio (90 ° C., 10 seconds)”) at 90 ° C. for 10 seconds (warm water treatment) of the shrink film (before shrink processing) of the present invention in the main shrinkage direction is Although not particularly limited, 20% or more (eg, 20 to 90%) is preferable, more preferably 30% or more (eg, 30 to 85%), still more preferably 40% or more (eg, 40 to 80%) More preferably, it is 45% or more (for example, 45 to 80%), more preferably 60% or more (for example, 60 to 80%). If the thermal contraction rate (90 ° C., 10 seconds) is less than 20%, the shrinkage process in which the shrink label is brought into heat contact with the container is not sufficiently shrunk, making it difficult to follow the shape of the container. The finish may be poor for shaped containers. The “main shrinkage direction” is the direction in which the thermal contraction rate is the largest, and is generally the direction in which the stretching treatment is mainly performed, for example, a film stretched substantially in one direction in the width direction In the case of the width direction.

  The heat shrinkage ratio (90 ° C., 10 seconds) in the direction perpendicular to the main shrinkage direction of the shrink film (before shrink processing) of the present invention is not particularly limited, but is preferably -5 to 15%, more preferably -3 to 10%.

The density of the shrink film of the present invention (shrink before processing) is not particularly limited, but is preferably 1.20 g / cm ³ or less, more preferably 1.15 g / cm ³ or less, from the viewpoint of the shrink label and low density, 1.05 g / cm ³ or less is more preferable, and particularly preferably less than 1.00 g / cm ³ . The lower limit of the density is not particularly limited, but may be, for example, 0.8 g / cm ³ or more.

  When the shrink film of the present invention is transparent, the haze value (in accordance with JIS K 7136, thickness 40 μm, unit:%) of the shrink film is not particularly limited, but is preferably 15% or less, more preferably Preferably it is 10% or less, More preferably, it is 7% or less. When the haze value exceeds 15%, in the case of a shrink label (back print shrink label), printing is performed on the inner side of the shrink film (the side which becomes the container side when the shrink label is attached to the container) and the printing is indicated through the shrink film. When making a product, the print may be cloudy and the decorativeness may be reduced. However, even when the haze value exceeds 15%, the film may be opaque in applications other than the above applications where printing is shown through a shrink film (table printing shrink label) and can be sufficiently used.

[Shrink label]
The shrink label of the present invention is at least a shrink label having the shrink film of the present invention. The shrink label of the present invention may have a layer other than the shrink film of the present invention.

(Layers other than the shrink film of the present invention)
The layer other than the shrink film of the present invention, which is included in the shrink label of the present invention, is not particularly limited, but other layers such as a printing layer, nonwoven fabric and foam sheet, adhesive layer (pressure sensitive adhesive layer, heat sensitive Adhesive layer, etc., a protective layer, an anchor coat layer, a primer coat layer, a coating layer, an antistatic layer, an aluminum vapor deposition layer and the like.

(Printed layer)
The printing layer is not particularly limited, and examples thereof include known and commonly used printing layers and the like used in shrink labels. In addition, as the printing layer, for example, a design printing layer (color printing layer etc.) such as a brand name, an illustration, a figure or design such as handling precautions, a background printing layer formed in a single color such as white, a film Examples include a protective print layer provided to protect the print layer, and a primer print layer provided to enhance the adhesion between the film and the print layer. The printing layer is not particularly limited, but may be provided only on one side of the shrink film of the present invention, or may be provided on both sides of the shrink film of the present invention. Moreover, the said printing layer may be provided in the whole surface of the surface (surface by which a printing layer is provided) of the shrink film of this invention, and may be provided in one part. Furthermore, although the said printing layer is not specifically limited, A single layer may be sufficient and a multilayer may be sufficient.

  Although the said printing layer is not specifically limited, It is preferable to contain binder resin as an essential component. Furthermore, if necessary, additives such as color pigments such as blue, red, yellow, black and white, lubricants, dispersants and antifoaming agents may be included. The said binder resin etc. may each use only 1 type, and may use 2 or more types.

  The binder resin is not particularly limited, and for example, a resin used as a binder resin in a known or commonly used printing layer or printing ink can be used. Examples of the binder resin include acrylic resins, urethane resins, polyester resins, polyamide resins, cellulose resins (including nitrocellulose resins), and vinyl chloride-vinyl acetate copolymer resins. The color pigment is not particularly limited. For example, color pigments used in known or commonly used printing layers and printing inks can be used. As the above-mentioned color pigment, for example, white pigments such as titanium oxide (titanium dioxide), base pigments such as copper phthalocyanine blue, carbon black, aluminum flakes, mica (mica), other color pigments, etc. can be selected and used according to applications. . In addition, as the above-mentioned color pigment, an extender pigment such as alumina, calcium carbonate, barium sulfate, silica, acrylic beads and the like can also be used for the purpose of gloss adjustment and the like.

  Although the thickness of the said printing layer is not specifically limited, For example, 0.1-10 micrometers is preferable, More preferably, it is 0.3-5 micrometers. If the thickness is less than 0.1 μm, it may be difficult to provide the print layer uniformly, and partial “swimming” may occur to impair the decorativeness or make printing as designed difficult. There is. In addition, when the thickness exceeds 10 μm, a large amount of printing ink is consumed, which may increase the cost, make it difficult to apply uniformly, or may make the print layer fragile and easily peel off, In some cases, it is difficult for the print layer to follow the thermal contraction of the shrink film during shrink processing.

  1 and 2 are each a schematic view (partial cross-sectional view) showing a preferred example of the shrink label of the present invention. The shrink label 3 of the present invention described in FIG. 1 includes the shrink film 1 of the present invention and the printing layer 2 provided on one side of the shrink film 1 of the present invention. The shrink film 1 of the present invention includes a base layer portion 12 and a surface layer 11 provided one on each side of the base layer portion 12. The base layer portion 12 has the outermost layer (layer in contact with the surface layer 11) as a B layer 12a, and a B layer 12a and an A layer 12b are alternately laminated in a total of nine layers. In the base layer portion 12, the number of interfaces formed by the B layer 12a and the A layer 12b being adjacent (directly laminated) is eight. In addition, the surface layer 11 and the base layer portion 12 are directly laminated without interposing another layer. Specifically, the surface layer 11 and the B layer 12a which is the outermost layer of the base layer portion 12 are directly laminated without interposing another layer. In addition, the A layer 12b intervenes between all the B layers 12a.

  The shrink label 3 of the present invention shown in FIG. 2 includes the shrink film 1 of the present invention and the printing layer 2 provided on one side thereof, and the shrink film 1 of the present invention comprises the surface layer 11 and the base layer portion 12 The base layer portion 12 is formed by laminating a total of 17 B layers 12a and A layers 12b alternately, with the outermost layer (layer in contact with the surface layer 11) as a B layer 12a. In the base layer portion 12, the number of interfaces formed by the B layer 12a and the A layer 12b being adjacent (directly laminated) is sixteen. Also in FIG. 2, the surface layer 11 and the base layer portion 12 are directly laminated without another layer interposed, and the surface layer 11 and the B layer 12 a which is the outermost layer of the base layer portion 12 intervene the other layer. There is no direct lamination. In addition, the A layer 12b intervenes between all the B layers 12a. In the shrink label 3 of the present invention shown in FIG. 1 and FIG. 2, the B layer 12 a and the A layer 12 b may have an opposite positional relationship.

  The thickness (total thickness) of the shrink label of the present invention is not particularly limited, but is preferably 10 to 110 μm, more preferably 15 to 60 μm, and still more preferably 20 to 50 μm. When the thickness is 10 μm or more, the rigidity is further increased and the rigidity of the label is increased, which is preferable.

Although the density of the shrink label (before shrink processing) of the present invention is not particularly limited, it is preferably 0.85 to 1.25 g / cm ³ , more preferably 0.90 to 1.20 g / cm ³ .

  The shrink label of the present invention is, for example, a cylindrical shrink label of the type in which both ends of the label are sealed with a solvent or adhesive and made cylindrical and attached to a container, or one end of the label is attached to the container and the label is wound After that, it can be used as a winding type shrink label in which the other end is overlapped with one end to form a tubular shape. Among the above, the shrink film of the present invention is particularly preferably used for a cylindrical shrink label from the viewpoint of high rigidity. That is, the shrink label of the present invention is preferably a cylindrical shrink label. Hereinafter, the cylindrical shrink label using the shrink label of this invention may be called "the cylindrical shrink label of this invention."

  An example of the cylindrical shrink label which is a preferable embodiment of the shrink label of this invention is demonstrated using FIG.3 and FIG.4. The cylindrical shrink label 4 of the present invention shown in FIG. 3 is formed into a cylindrical shape by superimposing the other end on the outside of one end of the shrink label of the present invention formed in a rectangular shape, and the inner surface and one end of the other end. It is a cylindrical body in which a seal portion 41 is formed by bonding the outer surface of the portion with a solvent or an adhesive. The cylindrical shrink label of the present invention includes the shrink film of the present invention, and the shrink film of the present invention is oriented at least in the circumferential direction D of the cylindrical shrink label of the present invention, and can be thermally shrunk in that direction. The cylindrical shrink label of the present invention is preferably mounted such that the circumferential direction is the main contraction direction.

  FIG. 4 is a cross-sectional view taken along the line A-A 'in FIG. 3, that is, an enlarged view of the main part of the cylindrical shrink label 4 of the present invention in the vicinity of the seal portion. It is joined by an adhesive 53. Specifically, the shrink label 3 of the present invention is designed and printed in the area excluding the area of the predetermined width from the end of the other end of one surface (surface of the inner surface of the cylindrical shape) of the shrink film 1 of the present invention. The layer 52 is formed, and the background print layer 51 is formed over substantially the entire area excluding the area of a predetermined width from the end of the other end of one surface of the shrink film 1 so as to cover the design print layer 52 There is. For this reason, in the shrink label 3 of the present invention, the background print layer 51 and the design print layer 52 are not formed in a region having a predetermined width from the end of the other end, and the shrink film 1 of the present invention is exposed. A film exposed surface is formed, and the seal portion 41 is a solvent or an adhesive, which is the film exposed surface formed on the inner surface side of the other end of the shrink label 3 of the present invention and the outer surface (film exposed surface) of one end. It is joined by 53. That is, in the seal portion 41, it is preferable that the shrink films 1 according to the present invention be bonded with a solvent or an adhesive 53. In addition, since the adhesiveness is not affected even if it has printing layers, such as a background printing layer and a design printing layer, among the said both ends, the part which is not joined may have a printing layer.

  In the cylindrical shrink label 4 of the present invention in FIG. 4, one end extends to a position where the end overlaps the background print layer 51 at the other end, and the background print layer 51 at the one end and the other end. A region in which the two overlap with one another via the shrink film 1 is formed. Therefore, there is no region where the background print layer 51 does not exist in the thickness direction. The cylindrical shrink label according to the present invention may have a structure in which the end of the one end and the background print layer on the other end are overlapped as shown in FIG. The structure extends to a region overlapping with the surface and does not extend to a position where the end of one end overlaps with the background print layer on the other end side, and the end of the one end and the background print layer on the other end do not overlap It is also good.

  Examples of the above-mentioned design print layer include a layer displaying a product name, an illustration, a handling instruction and the like. Although it does not specifically limit as said design printing layer, For example, the said printing layer etc. can be used. More specifically, the design print layer is formed of a plurality of print layers different in color pigment so as to have a desired design. Although the thickness of the said design printing layer is not specifically limited, 0.1-8 micrometers is preferable.

  The said background printing layer is a printing layer used as the background of the design printing layer when the cylindrical shrink label of this invention is observed from the outer side of a pipe | tube. The background print layer is not particularly limited, but, for example, the print layer can be used. Among them, a background print layer such as a white print layer containing 20 to 60% by weight of titanium oxide as a color pigment is preferable from the viewpoint of being a background of the design print layer. Although the thickness of the said background printing layer is not specifically limited, 0.5-10 micrometers is preferable.

  Although the width | variety of the said seal | sticker part is not specifically limited, 1-10 mm is preferable, More preferably, it is 2-4 mm.

  The shrink film of the present invention has a base layer portion and surface layers provided on both sides of the base layer portion, the surface layer is a layer containing 50% by weight or more of a polyester resin, and the base layer portion is It contains 5 to 65 layers, and includes an A layer containing 50% by weight or more of a polyolefin resin as the layer. Thus, the shrink label of the present invention has a base film portion having a multilayer structure including a layer mainly composed of a polyolefin resin and a shrink film having a surface layer and the above-mentioned surface layer, so a polyolefin resin which is a relatively soft resin While having a layer as the main component, the rigidity can be increased while maintaining the characteristics of the polyester resin and the polyolefin resin.

[Method for producing shrink label of the present invention]
The method for producing a shrink label of the present invention at least includes the step of producing the shrink film of the present invention. In the present specification, the above-mentioned "step of producing the shrink film of the present invention" may be referred to as "film producing step". The method for producing a shrink label of the present invention may further include other steps (steps other than the above-mentioned film producing step) such as a step of forming a layer other than the shrink film of the present invention.

(Film making process)
In the film preparation step, the shrink film of the present invention can be prepared by a conventional method such as melt film formation. Among them, the melt film forming method (in particular, the T-die method) is preferable. Moreover, as a method of lamination, a conventional method, for example, co-extrusion method (feed block method, multi manifold method, etc.), dry lamination method, etc. can be used. Among them, the co-extrusion method is preferable, and the feed block method is preferable. Furthermore, it is preferable to perform multilayering of the base layer portion using a layer multiplier, especially using a combination of a feed block and a layer multiplier. The layer multiplier is an apparatus for forming a film layer in multiple layers. The method of forming a multilayer film layer by the layer multiplier is not particularly limited, but a method of laminating the divided film layer in the thickness direction after dividing the film layer in the width direction may be mentioned. In the present specification, the above-mentioned "layer multiplier" may be simply referred to as "multiplier". The above-mentioned multiplier can be obtained, for example, from EDI, Inc. and Klolen.

  A specific example of the coextrusion method (feed block method) will be described below. For example, the raw material for forming the base layer portion and the raw material for forming the surface layer are respectively introduced into a plurality of extruders respectively set to predetermined temperatures, and co-extrusion is performed from the T-die. At this time, it is preferable to combine the feed block and the multiplier to make the base layer part into a multi-layered structure to have a predetermined laminated structure. In addition, if necessary, a gear pump may be used to adjust the supply amount. Furthermore, it is preferable to remove foreign matter by using a filter, because film breakage can be reduced. In addition, although extrusion temperature changes also with types of raw material to be used and is not specifically limited, 150-250 degreeC is preferable. A laminated unstretched film (sheet) can be obtained by quenching the co-extruded polymer using a cooling drum or the like.

  Although the said film preparation process is not specifically limited, When a base-layer part is formed from A layer and B layer, the raw material ("raw material (a)" may be called) which comprises A layer, and B layer The first to melt (or melt and knead) the constituent material (sometimes referred to as "raw material (b)") and the raw material (sometimes referred to as "raw material (c)") that constitute the surface layer A second step of laminating the raw material (a) and the raw material (b) melted (or melt-kneaded) in the first step, and forming a laminate by further layering; It is preferable to include at least a third step of laminating the raw material (c) melted in the first step on both sides of the laminate formed in the second step. Furthermore, other steps (steps other than the first step, the second step, and the third step) may be included. The other steps may be, for example, before the first step, after the third step, between the first step and the second step, between the second step and the third step, etc. It may be provided at the position of.

  In the first step, it is preferable to melt (or melt and knead) each of the raw material (a), the raw material (b) and the raw material (c) using a known or commonly used extruder. For example, the raw material (a), the raw material (b) and the raw material (c) can be charged into three extruders respectively set to predetermined temperatures, and melting (or melt kneading) can be performed. Although the extrusion temperature is not particularly limited, 150 to 250 ° C. is preferable.

  The laminate obtained by laminating the raw material (a) and the raw material (b) melted in the first step in the second step and laminating them in multiple layers is not particularly limited. The laminate formed by sequentially laminating the raw material (a) and the raw material (b), or simultaneously laminating (co-extrusion) using the feed block, is further formed into a multilayer using It may be a laminated body. Although it does not specifically limit for the said lamination | stacking, It is preferable to use combining a feed block and a multiplier. Only one or two or more of the feed block and the multiplier may be used. In the laminate, the total of the number of layers formed of the raw material (a) and the number of layers formed of the raw material (b) is preferably 5 to 65, more preferably 5 to 33, still more preferably Is 9 to 33 layers. The laminate obtained in the second step forms the base layer portion of the shrink film of the present invention.

  In the second step, the raw material (a) and the raw material (b) are laminated, and the laminated body obtained by further laminating is specifically, for example, the raw material (a) melted in the first step. And extrude the raw material (b) using a feed block to produce a laminate (may be referred to as “laminate 1”) having the structure of [raw material (a) / raw material (b) / raw material (a)] Then, the above laminate 1 is stacked as one unit using a multiplier [raw material (a) / raw material (b) / raw material (a) / raw material (a) / raw material (b) / raw material (a) A laminate (sometimes referred to as “laminate 2”) having a structure of / / ... / raw material (a) / raw material (b) / raw material (a) can be obtained.

  In addition, in the second step, the raw material (a) and the raw material (b) are laminated, and the multi-layered laminate is specifically, for example, a raw material melted in the first step. A laminate having a configuration of [raw material (b) / raw material (a) / raw material (b)] by extruding (a) and the raw material (b) using a feed block (sometimes referred to as “laminated body 3” ), And then laminating the laminate 3 as one unit, using a multiplier, [raw material (b) / raw material (a) / raw material (b) / raw material (b) / raw material (a) / It is also possible to obtain a laminated body (sometimes referred to as “laminated body 4”) having a structure of raw material (b) /... / Raw material (b) / raw material (a) / raw material (b)].

  In addition, in the second step, the raw material (a) and the raw material (b) are laminated, and the multi-layered laminate is specifically, for example, a raw material melted in the first step. (A) and the raw material (b) are extruded using a feed block to produce a laminate (may be referred to as “laminated body 5”) having the structure of [raw material (a) / raw material (b)], Then, the above laminate 5 is laminated as one unit using a multiplier [raw material (a) / raw material (b) / raw material (a) / raw material (b) /... / Raw material (a) / The laminated body (sometimes called "the laminated body 6") which has a structure of a raw material (b) can be obtained. In addition, if the said laminated body 6 is chased from reverse, [raw material (b) / raw material (a) / raw material (b) / raw material (a) / ... / raw material (b) / raw material (a)] It is also a laminate having a structure.

  In the third step, the raw material (c) melted in the first step is placed on both sides of the laminate (for example, the laminate 2, 4 or 6) formed in the second step. When laminating, it is preferable to use a feed block. The laminated raw material (c) forms the surface layer of the shrink film of the present invention. According to the third step, there is obtained a multilayer structure in which the raw material (c) melted in the first step is laminated on both sides of the laminate formed in the second step.

  Although not particularly limited, the laminate unformed film is obtained by coextruding the laminate formed through the first step, the second step, and the third step from a T-die and quenching using a cooling drum or the like. (Sheet) can be obtained.

  In addition, [a raw material (a) / a raw material (b) / a raw material (a) / a raw material (a) / a raw material (b) / a raw material (a) / ... / a raw material (a) / a raw material (b) / a raw material (a) The laminate 2 having the structure a) has a structure of [A layer / B layer / A layer / A layer / B layer / A layer /... / A layer / B layer / A layer] It is supposed to be the base layer part, but in fact, the part of [A layer / A layer] formed from [raw material (a) / raw material (a)] laminated with the same material of laminate 2 can not see the interface 1 Since it becomes one A layer, it becomes a base layer part having a structure of [A layer / B layer / A layer / B layer /... / A layer / B layer / A layer]. Similarly, the portion of [B layer / B layer] formed from the same material of the above-mentioned laminate 4 is stacked [raw material (b) / raw material (b)], so that the interface is not visible and it becomes one B layer. The base layer portion derived from the laminate 4 is a base layer portion having a structure of [B layer / A layer / B layer / B layer / A layer / B layer /... / B layer / A layer / B layer]. In actuality, the base layer portion has a structure of [B layer / A layer / B layer / A layer /... / B layer / A layer / B layer]. When the B layer is the A layer in the base layer portion, that is, a laminate formed by laminating the raw materials for forming two different A layers (A1 layer and A2 layer) in the base layer portion [A1 When the layer / A2 layer is present, the part of [A1 layer / A2 layer] does not become one A layer because the interface is seen. When the surface layer and the outermost layer layer (resin layer) of the base layer portion are layers made of the same resin composition as a raw material, the interface is not visible, and the surface layer and the outermost layer layer of the base layer portion It becomes one layer (surface layer).

  Although it does not specifically limit as said other step, The step of extending | stretching, the step of surface-treating, etc. are mentioned. For example, the laminated unstretched film produced in the third step further has a step of performing stretching.

  The step of performing the stretching (stretching step) is biaxial stretching in the longitudinal direction (film production line direction, also referred to as MD direction) and the width direction (direction orthogonal to the longitudinal direction, also referred to as TD direction). Uniaxial stretching in the direction or the like can be used. The stretching method may be any of a roll method, a tenter method, and a tube method. In the case of biaxial stretching, the film may be simultaneously stretched in two axes or may be sequentially stretched in two axes. More specifically, for example, after stretching at a stretching temperature of 65 to 100 ° C. and a stretching ratio of 1.05 to 1.50 in the longitudinal direction by a roll method, the stretching temperature is 70 to 100 ° C. in the width direction by a tenter method It is stretched at a magnification of 3 to 8 (preferably 4 to 7).

  Examples of the step of surface treatment include the step of subjecting the surface of the shrink film of the present invention to conventional surface treatment such as corona discharge treatment, primer treatment and frame treatment.

  Although the example in which the base layer portion is formed of only the A layer and the B layer has been described in the film forming step, the base layer portion and the laminated unstretched film can be obtained by the same steps also when including layers other than the A layer and the B layer. It can be made. Moreover, although the said film preparation process showed the example which melts and uses 3 types of raw materials, it is not limited to this, Two types of raw materials (For example, a raw material (a) and a raw material (b)) A first step of melting, and a second step of laminating two types of raw materials (eg, the raw material (a) and the raw material (b)) melted in the first step adjacently to form a laminated body; In this case, the third stage is not provided, and the outermost layer of the second stage laminate is the surface layer.

(Other process)
The method for producing a shrink label of the present invention is not particularly limited, but may have a step of providing a print layer, a step of providing a protective layer, and the like as steps (other steps) other than the film preparation step.

  In the step of providing the printing layer, the printing layer is formed by applying a printing ink on at least one surface of the shrink film of the present invention and performing one or more printing steps in which the printing ink is solidified by drying or the like. For example, one or more printing steps may be performed to form a design printing layer, and then one or more printing steps may be performed to form a background printing layer. A well-known and usual printing method can be used for the process of providing said printing layer, and a gravure printing method or a flexographic printing method is especially preferable.

  The said printing ink is manufactured by mixing the said binder resin, the said color pigment, a solvent, another additive, etc. as needed, for example. The mixing can be carried out by a known or conventional mixing method, and is not particularly limited. For example, a mixer such as a paint shaker, butterfly mixer, planetary mixer, pony mixer, dissolver, tank mixer, homo mixer, homo disper, etc. A mixing apparatus such as a roll mill, a sand mill, a ball mill, a bead mill, a mill such as a line mill, or a kneader is used. The mixing time (retention time) during mixing is not particularly limited, but is preferably 10 to 120 minutes. The obtained printing ink may be used after filtration, if necessary. Each of the above components (binder resin, color pigment, solvent, and other additives) may be used alone or in combination of two or more.

  As said solvent (solvent), the organic solvent etc. which are normally used for printing ink can be used. Examples of the solvent include esters of acetic acid ester (ethyl acetate, propyl acetate, butyl acetate and the like); alcohols such as methanol, ethanol, isopropyl alcohol, propanol and butanol; ketones such as methyl ethyl ketone and methyl isobutyl ketone; toluene, xylene Aromatic hydrocarbons such as; aliphatic hydrocarbons such as hexane and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; glycols such as ethylene glycol and propylene glycol; ethylene glycol monopropyl ether, propylene glycol monomethyl ether, propylene Glycol ethers such as glycol monobutyl ether; glycol ether esters such as propylene glycol monomethyl ether acetate It is. The above-mentioned solvent can be removed by drying after applying the printing ink to the shrink film of the present invention. In addition, the said solvent (solvent) also includes the meaning of "dispersion medium."

(Method of manufacturing cylindrical shrink label)
Although the manufacturing method of the cylindrical shrink label of this invention is not specifically limited, For example, it is as follows. A long, shrink film of the present invention is optionally provided with a printing layer or the like, and then slit to a predetermined width, and a long label (a longitudinal direction) in which a plurality of shrink labels of the present invention are continuous. Get the body. This label long body is formed into a cylindrical shape so that the other end portion is outside the one end portion so that the main contraction direction (that is, the main contraction direction of the shrink film of the present invention) becomes the circumferential direction. Then, the overlapped portions are sealed in a strip shape with a predetermined width, and both end portions are joined to obtain a long cylindrical label continuous body (long cylindrical shrink label). By cutting this long cylindrical shrink label in the width direction such that the longitudinal direction has a predetermined length, one cylindrical shrink label having a predetermined length in the height direction (a cylindrical shrink label of the present invention ) Can be obtained.

  In addition, when providing the perforation for label cutting in a cylindrical shrink label, the perforation of predetermined length and pitch is formed in the longitudinal direction (direction orthogonal to the circumferential direction). The perforations can be applied by a conventional method (for example, a method of pressing a disk-like cutter having a cut portion and a non-cut portion repeatedly formed around the periphery, a method of using a laser, etc.). The step of applying perforations can be appropriately selected, for example, after the step of providing the printing layer, or before and after the step of processing into a cylindrical shape.

[Labeled container]
Although the shrink label of the present invention is not particularly limited, it is attached to a container and used as a labeled container. In addition, the shrink label of this invention may be used for to-be-adhered bodies other than a container. For example, by attaching the shrink label of the present invention (in particular, a cylindrical shrink label) around the container so that the shrink label of the present invention becomes cylindrical and attaching it to the container by heat contraction, the label is attached A container (a labeled container having a shrink label of the present invention) is obtained. The above containers include, for example, bottles for soft drinks such as PET bottles, milk bottles for home delivery, containers for food such as seasoning, bottles for alcoholic beverages, containers for chemical products such as pharmaceutical containers, detergents and sprays, and toiletries. Containers, cup noodle containers etc. are included. Although it does not specifically limit as a shape of the said container, For example, various shapes, such as cylindrical and square bottle types, and a cup type, are mentioned. Moreover, as a material of the said container, although it does not specifically limit, For example, plastics, such as PET, glass, a metal, etc. are mentioned.

  The labeled container can be produced, for example, by externally fitting a cylindrical shrink label into a predetermined container, and then heat shrinking the cylindrical shrink label by heat treatment to closely follow the container (shrink processing). Examples of the method of the heat treatment include a method of passing through a hot air tunnel or a steam tunnel, a method of heating with radiant heat such as infrared rays, and the like. In particular, a method of treating with steam at 80 to 100 ° C. (passing through a heating tunnel filled with steam and steam) is preferable. Also, dry steam at 101 to 140 ° C. can be used. Although the said heat processing is not specifically limited, It is preferable to implement in the temperature range which the temperature of a shrink film becomes 85-100 degreeC (especially 90-97 degreeC). The shrink film of the present invention can be heat-treated particularly at a high temperature, so that it can be used for containers requiring high heat shrinkability. Moreover, as for the processing time of heat processing, 4 to 20 seconds are preferable from a viewpoint of productivity and economical efficiency.

  EXAMPLES The present invention will be described in more detail based on examples given below, but the present invention is not limited by these examples.

  In Table 1, the raw material for surface layer (raw material (c)), the raw material for layer A (raw material (a)), the raw material for layer B (raw material (b)) used in Examples and Comparative Examples, Examples And the structure of the shrink film and shrink label which were produced by the comparative example, evaluation results, etc. were shown.

Example 1
(material)
36% by weight of a polypropylene resin A (manufactured by ExxonMobil Chemical Co., Ltd., trade name "Vistamax 3020FL") as a raw material (material for A layer) constituting a layer A Name: “Wintec WFX 6”: 39% by weight Polyester resin A (Eastman Chemical, product name: “EMBRACE LV”): 9% by weight Resin resin A (Arakawa Chemical Industries, Ltd.): product name: “Alcon 16 wt% of P125 ") was used.
55% by weight of a polypropylene resin A, 11% by weight of a polypropylene resin B, 30% by weight of a polyester resin A, and 4% by weight of a petroleum resin A as raw materials (materials for the B layer) constituting the layer B .
100 weight% of polyester-based resin A was used as a raw material (raw material for surface layer) which comprises a surface layer.

(Shrink film)
The raw material for A layer was put into the extruder x heated to 220 ° C., the raw material for layer B was put into the extruder y heated to 220 ° C., and the raw material for surface layer was put into the extruder z heated to 220 ° C. Melt extrusion was performed using the above three extruders. The raw material for layer A and the raw material for molten layer B are combined using a laminating apparatus combining a feed block of two types and three layers type and a multiplier of 4 divisions, for raw material for layer B / layer A The two-kind / three-layer structure of the raw material / B layer material is divided, merged, and stacked as one repeating unit, and a laminate (I) (having four layers of the two-type and three-layer structure (repeating number 4)) The raw materials for the surface layer which had been melted were joined and laminated on both sides of the laminate (I) using feed blocks to obtain a laminate (II). Furthermore, the laminate (II) was extruded from a T-die and then quenched on a casting drum cooled to 25 ° C. to obtain a laminated unstretched film in which surface layers were provided on both sides of the base layer portion. .
Next, a long film of a stretched film (shrink film) which is mainly stretched in the width direction by having the above laminated unstretched film stretched by 5 times at 85 ° C. in the width direction and is mainly stretched in the width direction I got

Examples 2 and 3
As shown in Table 1, the shrink film was obtained in the same manner as Example 1, changing the composition and component ratio of the raw material (a), the raw material (b) and the raw material (c).

  In Examples 1 to 3, the shrink film has an 11-layer structure of [surface layer / B layer / A layer / B layer / A layer / B layer / A layer / B layer / A layer / B layer / surface layer]. It has become. In the above-mentioned shrink film, the base layer part is 12 layers since repeating units of 2 types and 3 layer constitution are laminated by repeating number 4 but in actuality the interface between layers is a part where materials for B layer overlap. It can not be seen, it overlaps and it becomes one layer. For this reason, the base layer portion has nine layers of [B layer / A layer / B layer / A layer / B layer / A layer / B layer / A layer / B layer], and the outermost layer of the base layer portion is It is B layer. Further, in the base layer portion, the number of the interfaces where the A layer and the B layer are formed adjacent to each other is eight. In Examples 1 and 2, the B layer is also an A layer. That is, in the base layer portion, two A layers (A1 layer and A2 layer) having different raw material compositions are alternately stacked.

Comparative Example 1
(material)
36% by weight of a polypropylene resin A, 39% by weight of a polypropylene resin B, 9% by weight of a polyester resin A, and 16% by weight of a petroleum resin A were used as raw materials (raw materials for layer A) forming the layer A .
55% by weight of a polypropylene resin A, 11% by weight of a polypropylene resin B, 30% by weight of a polyester resin A, and 4% by weight of a petroleum resin A as raw materials (materials for the B layer) constituting the layer B .
100 weight% of polyester-based resin A was used as a raw material (raw material for surface layer) which comprises a surface layer.

(Shrink film)
The raw material for A layer was put into the extruder x heated to 220 ° C., the raw material for layer B was put into the extruder y heated to 220 ° C., and the raw material for surface layer was put into the extruder z heated to 220 ° C. Melt extrusion was performed using the above three extruders. The raw material for layer A and the raw material for layer B are combined in two types and three layers, using a feed block having two types and three layers of joining method, and two types and three layers of raw material for B layer / raw material for A layer / raw material for B layer The layered product (III) was produced, and the melted raw material for surface layer was merged and laminated on both sides of the layered product (III) using feed blocks to obtain a layered product (IV). Furthermore, the laminate (IV) was extruded from a T-die, and then quenched on a casting drum cooled to 25 ° C. to obtain a laminated unstretched film in which surface layers were provided on both sides of the base layer portion. .
Next, a long film of a stretched film (shrink film) which is mainly stretched in the width direction by having the above laminated unstretched film stretched by 5 times at 85 ° C. in the width direction and is mainly stretched in the width direction I got

  The shrink film has a five-layer structure of [surface layer / B layer / A layer / B layer / surface layer]. Accordingly, in the shrink film, the base layer portion has a three-layer structure of [B layer / A layer / B layer], and the outermost layer of the base layer portion is a B layer. Further, in the base layer portion, the number of the interfaces formed when the A layer and the B layer are adjacent is two.

Comparative example 2
As shown in Table 1, the shrink film was obtained in the same manner as in Comparative Example 1 by changing the composition and component ratio of the raw material (a), the raw material (b) and the raw material (c).

(Evaluation)
The following evaluation was performed about the shrink film obtained by the Example and the comparative example. The evaluation results are shown in Table 1.

(1) Compressive strength (rigidity) (ring crush method)
Evaluation was performed using the shrink film (before shrink process) obtained by the Example and the comparative example. In accordance with JIS P 8126, the compressive strength of the shrink label was measured under the following conditions. The measurement direction is the longitudinal direction of the shrink film. In addition, the evaluation result described in Table 1 is an average value of the result evaluated by the following test number.
Measuring device: Autograph (AGS-50G: load cell type 500N) manufactured by Shimadzu Corporation
Sample size: 15 mm (longitudinal direction) x 152.4 mm (width direction: main contraction direction)
Number of tests: 5 times

(2) Transparency (haze value)
The shrink film obtained in Examples and Comparative Examples was used as an evaluation sample, and the haze value (unit:%) was measured according to JIS K 7136 using "Haze-guard II" manufactured by Toyo Seiki Seisakusho Co., Ltd. .

  As can be seen from Table 1, the shrink label of the present invention of Example 1 uses the A layer and B layer of the same raw material composition, but the base layer portion does not have 5 to 65 layers. In comparison, the film had high compressive strength, excellent label rigidity, and excellent transparency. In addition, the shrink label of the present invention of Example 2 uses the A layer and the B layer of the same raw material composition, but the base layer portion has a film compared to the shrink label of Comparative Example 2 having 5 to 65 layers. The compressive strength was high, the rigidity of the label was excellent, and the transparency was also excellent. In addition, the shrink label of the present invention of Example 3 was high in the compressive strength of the film, excellent in the rigidity of the label, and excellent in the transparency.

DESCRIPTION OF SYMBOLS 1 shrink film 11 surface layer 12 base layer part 12a B layer 12b A layer 2 printed layer 3 shrink label of this invention 4 cylindrical shrink label of this invention 41 seal part D circumferential direction 51 background print layer 52 design print layer 53 Solvent or adhesive

Claims (4)

A shrink label having a shrink film,
The shrink film has a base layer portion and surface layers provided on both sides of the base layer portion,
The surface layer contains 50% by weight or more of a polyester resin,
The base layer portion includes 5 to 65 layers, and in the base layer portion , a layer containing 50% by weight or more of a polyolefin resin (A layer) and 10 to 90% by weight of a polyolefin resin; A shrink label in which layers containing 90% by weight (B layer) are alternately laminated . A shrink label having a shrink film,
The shrink film has a base layer portion and surface layers provided on both sides of the base layer portion,
The surface layer contains 50% by weight or more of a polyester resin,
The base layer portion includes 5 to 65 layers, and at least a layer (A layer) containing 50% by weight or more of a polyolefin resin as a layer in the base layer portion ,
A shrink label , wherein the outermost layer of the base layer portion is a layer (B layer) containing 10 to 50% by weight of a polypropylene resin and 50 to 90% by weight of a polyester resin . All the layers in the base layer part are layers containing 50% by weight or more of a polyolefin resin, and the layers containing 50% by weight or more of each polyolefin resin in the base layer part are respectively adjacent polyolefin resins. The shrink label according to claim 1 , wherein the density is different from that of the layer containing 50% by weight or more . The shrink label according to any one of claims 1 to 3, wherein the polyolefin resin in the layer A and / or the layer B is a propylene-α-olefin copolymer as a polypropylene resin .

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