JP5768297B2 - Shrink label - Google Patents

Description

  The present invention relates to a shrink label. More specifically, the present invention relates to a shrink label that is excellent in adhesion between a substrate, in particular, a polyester film substrate and a print layer, and also excellent in printability of the print layer.

  Currently, 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 to give display, decoration, and functionality. For example, from the merits of decoration, workability (followability to containers, etc.), wide display area, etc. Shrink labels are widely used. As such a shrink label, a label having a printing layer formed from printing ink on a substrate is widely used. As the substrate, a film made of a polyester resin, a polyolefin resin, a polystyrene resin, or the like is used according to required characteristics and applications.

  Especially, the film (polyester-type film) which consists of a polyester-type resin is inferior to the adhesiveness of printing ink, and it was difficult to obtain the shrink label excellent in the adhesiveness of a base material and a printing layer. For this reason, it has excellent adhesion to a printed layer having excellent adhesion to a polyester film, and further to a substrate made of various resins such as polyester resin, polyolefin resin and polystyrene resin. Therefore, a printing layer having excellent versatility has been demanded.

  As a printing ink that satisfies this requirement, for example, a printing ink containing a specific ratio of an acrylic resin and a cellulose resin and a specific solvent is known (see Patent Document 1). However, even with the printing ink, there is a problem that the adhesion is not sufficient particularly for a thin PET film having poor ink adhesion. Furthermore, a method for producing a printed matter for shrinkable labels is known in which a print layer containing a specific cellulose resin and an acrylic resin is provided on an anchor coat layer comprising an anchor coat agent containing nitrocellulose and a polyurethane resin. (See Patent Document 2). However, this production method has a problem in terms of safety and management because it uses a relatively large amount of flammable nitrocellulose.

  As described above, the present situation is that a shrink label having a printing layer excellent in adhesion to a polyester film having a wide range of thickness (various thicknesses) using a relatively safe acrylic resin has not been obtained. .

JP 2008-163215 A Japanese Patent No. 3895253

  The inventors of the present invention have a printed layer containing a urethane acrylic resin and an acrylic resin that exhibits excellent adhesion to many substrates commonly used for shrink labels, particularly for polyester films with a wide range of thicknesses. Also found excellent adhesion. Furthermore, the shrink label which has the said printing layer was discovered.

  However, the printing layer containing the urethane acrylic resin and the acrylic resin (or the printing ink forming the printing layer) has insufficient printability when it contains a pigment (particularly when it contains titanium oxide). In particular, the expressiveness such as the design of gradation expression is not sufficient.

  Accordingly, an object of the present invention is to exhibit excellent adhesion to many substrates used for shrink labels, particularly excellent adhesion to a wide range of polyester films, and also to printability (particularly gradation). An object of the present invention is to provide a shrink label having a printed layer that is also excellent in design and the like.

  As a result of intensive studies to achieve the above object, the present inventors have found that on at least one side of the base material, urethane acrylic resin, acrylic resin, pigment, and structural units and phosphate groups derived from lactone compounds. A print layer in which the content of the polymer containing a structural unit derived from a lactone compound and a phosphate group is controlled within a specific range is further provided. Thus, the present inventors have found that a shrink label having excellent adhesion between a substrate, particularly a polyester film substrate having a wide thickness and a printed layer, and excellent printability of the printed layer can be obtained. .

  That is, the present invention includes, on at least one side of the substrate, a urethane acrylic resin, an acrylic resin, a pigment, and a polymer containing a structural unit derived from a lactone compound and a phosphoric acid group, and further a cellulose type A structural unit derived from the lactone compound with respect to a total weight of 100 parts by weight of the urethane acrylic resin, the acrylic resin, and the cellulose resin in the printed layer, including a printed layer that includes or does not include a resin. And a content of the polymer containing a phosphate group is 1 to 20 parts by weight.

Furthermore, in the present invention, the content of the urethane acrylic resin is 4 to 40% by weight relative to a total weight of 100% by weight of the urethane acrylic resin, the acrylic resin, and the cellulose resin in the printed layer. The shrink label is provided in which the content of the acrylic resin is 40 to 96% by weight and the content of the cellulose resin is 0 to 20% by weight.
The printed layer contains a solvent, a urethane acrylic resin, an acrylic resin, a pigment, and a polymer containing a structural unit derived from a lactone compound and a phosphate group, or a solvent, a urethane acrylic resin, an acrylic. A coating ink containing a structural resin derived from a resin, a pigment, a lactone compound and a phosphoric acid group, and a printing ink containing a cellulose resin was applied to the surface of the substrate and dried. A printed layer is preferred.
It is preferable that the pigment is titanium oxide and the content of titanium oxide is 30 to 90% by weight with respect to the total weight (100% by weight) of the printed layer.

The shrink label of the present invention uses an acrylic resin as a resin component for forming the printed layer. For this reason, a hard printed layer can be formed relatively safely. Moreover, urethane acrylic resin is used as a resin component which forms a printing layer. For this reason, the adhesiveness of a base material and a printing layer improves especially also to a polyester-type film base material. Thereby, the peeling resistance of the shrink label, the scratch resistance, the rub resistance, and the ink cracking deterrence (ink cracking resistance) during shrink processing are improved.
Furthermore, the shrink label of this invention contains the polymer containing the structural unit and phosphate group derived from a lactone type compound in a printing layer. For this reason, the printability of the print layer is improved and, for example, the expression of gradation design by the print layer is excellent.

  The shrink label of the present invention includes, on at least one side of a substrate, a urethane acrylic resin, an acrylic resin, a pigment, and a polymer containing a structural unit derived from a lactone compound and a phosphate group, and further cellulose. A printing layer containing or not containing a resin based on the lactone compound for a total weight of 100 parts by weight of the urethane acrylic resin, the acrylic resin and the cellulose resin in the printing layer It has a printed layer whose content of the polymer containing a unit and a phosphate group is 1 to 20 parts by weight. In the present specification, the print layer may be referred to as “print layer of the present invention”.

In the present specification, the “urethane acrylic resin” in the printing layer of the present invention is referred to as “urethane acrylic resin (A)” or “component (A)”, and the “acrylic resin” is referred to as “acrylic resin ( B) ”or“ component (B) ”, the above“ cellulosic resin ”as“ cellulosic resin (C) ”or“ component (C) ”, and the“ pigment ”as“ pigment (D) ”or“ component (D ) ”And the“ polymer containing a structural unit derived from a lactone compound and a phosphate group ”may be referred to as“ lactone polymer (E) ”or“ component (E) ”, respectively. The “polymer containing a structural unit derived from a lactone compound and a phosphate group” may be referred to as “a lactone polymer containing a phosphate group”.
Furthermore, the urethane acrylic resin (A), the acrylic resin (B), and the cellulose resin (C) in the printing layer of the present invention may be collectively referred to as “specific resin”. When the cellulose resin (C) is not contained in the printing layer of the present invention, the urethane acrylic resin (A) and the acrylic resin (B) are “specific resins”, and the printing layer of the present invention includes When the cellulose resin (C) is included, the urethane acrylic resin (A), the acrylic resin (B), and the cellulose resin (C) are “specific resins”.

[Print layer of the present invention]
The printed layer of the present invention is an essential printed layer in the shrink label of the present invention. The printing layer of the present invention contains urethane acrylic resin (A), acrylic resin (B), pigment (D) and lactone polymer (E) as essential components. Moreover, although the printing layer of this invention may contain the cellulose resin (C) and does not need to contain it, it is preferable to contain a cellulose resin (C). Furthermore, the printing layer of the present invention may contain components (additives) other than the components (A), (B), (C), (D) and (E). Each of the above component (A), component (B), component (C), component (D), component (E) and additive may be used singly or in combination of two or more. Good.

(Urethane acrylic resin (A))
Although the said urethane acrylic resin (A) is not specifically limited, It is a polymer (copolymer) comprised by making a urethane component and an acrylic component into essential structural components. In other words, the urethane acrylic resin (A) includes a urethane component part having a urethane bond and an acrylic component part containing a structural unit (structural unit) derived from a monomer having a (meth) acryloyl group in the molecule. It is a polymer. The urethane acrylic resin (A) is not particularly limited, but is a resin component that plays a role of improving the adhesion between the printing layer of the present invention and the substrate. The “(meth) acryloyl group” represents “acryloyl group [CH ₂ ═CHCO—]” and / or “methacryloyl group [CH ₂ ═C (CH ₃ ) CO—]”. A monomer having a (meth) acryloyl group has a structure of [CH ₂ ═CHCO—] and / or [CH ₂ ═C (CH ₃ ) CO—] in the molecule. “(Meth) acryl” means “acryl” and / or “methacryl” (any one or both of acryl and methacryl).

  The urethane acrylic resin (A) does not include the urethane acrylic resin corresponding to the component (E). That is, the urethane acrylic resin (A) excludes a urethane acrylic resin containing a structural unit derived from a lactone compound and a phosphate group in the molecule.

  The acrylic component in the urethane acrylic resin (A) includes a monomer (monomer) having a (meth) acryloyl group as an essential monomer component. That is, the acrylic component and the urethane acrylic resin (A) have at least a structural unit derived from a monomer having a (meth) acryloyl group. The monomer component constituting the acrylic component may contain a monomer component other than the monomer having a (meth) acryloyl group, but the monomer component constituting the acrylic component consists only of a monomer having a (meth) acryloyl group. It is preferable.

Examples of the monomer having the (meth) acryloyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, ( Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) (Meth) acrylic acid alkyl ester having a linear or branched alkyl group such as isononyl acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate [preferably C _1-12 alkyl (meth) acrylate Esters etc.]; (Meth) acrylic acid; carboxyl groups such as carboxyethyl acrylate (Meth) acrylic acid ester; 2-hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 6-hydroxyhexyl (meta) ) Hydroxyl group-containing (meth) acrylic acid ester such as acrylate, diethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate [preferably (meth) acrylic acid hydroxy C _1-8 alkyl ester etc.]; (Meth) acrylic acid cycloalkyl esters such as cyclohexyl acrylate; N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-di (Meth) acrylic acid amide derivatives such as til (meth) acrylamide; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dipropylamino And (meth) acrylic acid dialkylaminoalkyl esters such as propyl (meth) acrylate. The monomer which has the said (meth) acryloyl group can be used individually or in combination of 2 or more. Among these, as a monomer having a (meth) acryloyl group, from the viewpoint of compatibility with the acrylic resin (B), a (meth) acrylic acid alkyl ester having a linear or branched alkyl group [among others, (Meth) acrylic acid C _1-12 alkyl ester] and (meth) acrylic acid are preferable, and methyl methacrylate (MMA) and butyl methacrylate (BMA) are more preferable.

  The monomer component constituting the acrylic component other than the monomer having the (meth) acryloyl group is not particularly limited. For example, a carboxyl group-containing polymerizable unsaturated compound such as crotonic acid, itaconic acid, fumaric acid, maleic acid or the like Its anhydrides; Styrene compounds such as styrene, vinyltoluene and α-methylstyrene; Vinyl esters such as vinyl acetate and vinyl propionate; Vinyl halides such as vinyl chloride; Vinyl ethers such as methyl vinyl ether; (Meth) acrylonitrile And cyano group-containing vinyl compounds such as ethylene and propylene.

  Content of monomer having (meth) acryloyl group in the total amount of monomer component constituting the acrylic component, that is, (meth) in acrylic component (total acrylic component) (100% by weight) in urethane acrylic resin (A) The content of the structural unit derived from the monomer having an acryloyl group is not particularly limited, but is preferably 80% by weight or more (80 to 100% by weight), more preferably from the viewpoint of compatibility with the acrylic resin (B). Is 90% by weight or more (90 to 100% by weight).

  Although the urethane component in the said urethane acrylic resin (A) is not specifically limited, For example, a polyisocyanate compound and a polyol compound are comprised as a raw material component. That is, the urethane component has a structural unit derived from a polyisocyanate compound and a structural unit derived from a polyol compound. Especially, it is preferable that the said urethane component is comprised as an essential raw material component as a polyol compound from a viewpoint of the adhesive improvement of the printing layer of this invention, and a polyester-type film (base material). That is, it is preferable that the urethane component and the urethane acrylic resin (A) have at least a structural unit derived from a polyester polyol.

  Examples of the polyisocyanate compound include known diisocyanates such as aromatic diisocyanate, aliphatic diisocyanate, and alicyclic diisocyanate. Examples of the diisocyanates include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, and isophorone diisocyanate. The above diisocyanates can be used alone or in combination of two or more. If necessary, trifunctional or higher functional polyisocyanates and polyisocyanate adducts can be used in combination with the diisocyanates. Of these, isophorone diisocyanate (IPDI) and tolylene diisocyanate (TDI) are preferable from the viewpoint of improving the adhesion to the polyester film (base material).

  The polyester polyol is a polyester compound having two or more hydroxyl groups in the molecule (in one molecule), and among them, a polyester diol having two hydroxyl groups in the molecule is preferable. The polyester polyol is not particularly limited, but is preferably a polymer composed of a dicarboxylic acid component and a diol component as essential components. That is, the polyester polyol preferably has at least a structural unit derived from a dicarboxylic acid and a structural unit derived from a diol.

  Examples of the dicarboxylic acid include terephthalic acid, isophthalic acid, 2,5-dimethylterephthalic acid, 5-t-butylisophthalic acid, 4,4′-biphenyldicarboxylic acid, trans-3,3′-stilbene dicarboxylic acid, Trans-4,4′-stilbene dicarboxylic acid, 4,4′-dibenzyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalene Dicarboxylic acid, 2,7-naphthalenedicarboxylic acid, 2,2,6,6-tetramethylbiphenyl-4,4′-dicarboxylic acid, 1,1,3-trimethyl-3-phenylindene-4,5-dicarboxylic acid 1,2-diphenoxyethane-4,4′-dicarboxylic acid, diphenyl ether dicarboxylic acid, 2,5-ant Aromatic dicarboxylic acids such as sendicarboxylic acid, 2,5-pyridinedicarboxylic acid, and substituted products thereof; oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic 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, 1,12-dodecanedioic acid, and Aliphatic dicarboxylic acids such as these substitutes; 1,4-decahydronaphthalenedicarboxylic acid, 1,5-decahydronaphthalenedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid , Trans-1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedi Carboxylic acid, and include alicyclic dicarboxylic acids such as substituted versions thereof. Of these, aromatic dicarboxylic acids are preferable, and terephthalic acid (TPA) and isophthalic acid (IPA) are more preferable. The said dicarboxylic acid can be used individually or in combination of 2 or more.

  Examples of the diol 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, polyethylene glycol, polypropylene Aliphatic diols such as glycol; 1,2-cyclohexanedimethanol, 1,3-cyclohexane Cycloaliphatic diols such as sandimethanol, 1,4-cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol; 2,2-bis (4-β-hydroxyethoxyphenyl) propane And ethylene oxide adducts of bisphenol compounds such as bis (4-β-hydroxyethoxyphenyl) sulfone, and aromatic diols such as xylylene glycol. Of these, aliphatic diols are preferable, and neopentyl glycol (NPG) and ethylene glycol (EG) are more preferable. The above diols can be used alone or in combination of two or more.

  In addition to the above, the polyester polyol includes oxycarboxylic acids such as p-oxybenzoic acid and p-oxyethoxybenzoic acid; monocarboxylic acids such as benzoic acid and benzoylbenzoic acid; polyvalent carboxylic acids such as trimellitic acid; It may contain a structural unit derived from a monohydric alcohol such as polyalkylene glycol monomethyl ether; a polyhydric alcohol such as glycerin, pentaerythritol or trimethylolpropane.

  The polyester polyol (preferably polyester diol) is an aromatic dicarboxylic acid (particularly terephthalic acid) as a dicarboxylic acid component, particularly from the viewpoint of improving the adhesion between the aromatic polyester film (PET film or the like) and the printing layer of the present invention. , Isophthalic acid). Furthermore, the diol component preferably includes neopentyl glycol (NPG) or ethylene glycol (EG), which is a diol having a relatively short chain length between carbon atoms to which a hydroxyl group is bonded. By using NPG or EG, it is presumed that the density of the aromatic ring can be made relatively high, particularly when copolymerized with an aromatic dicarboxylic acid, but the aromatic polyester film and the printing layer of the present invention Adhesion is further improved. Therefore, the polyester polyol includes a structural unit derived from an aromatic dicarboxylic acid (particularly, terephthalic acid and / or isophthalic acid), and a structural unit derived from neopentyl glycol (NPG) and / or ethylene glycol (EG). The polyester polyol (particularly polyester diol) is particularly preferable.

  The polyol compound in the urethane component may contain a polyol compound other than the polyester polyol. Although it does not specifically limit as polyol compounds other than said polyester polyol, For example, ethylene glycol, diethylene glycol, 1,3-propanediol, propylene glycol (1,2-propanediol), butanediol (1,3-butanediol) , 1,4-butanediol, etc.), 1,6-hexanediol, low molecular weight glycols such as cyclohexanedimethanol; known diols such as polyether diols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, A trifunctional or higher functional polyol compound (polyether polyol, etc.) can be used.

  The content of the polyester polyol in the polyol compound in the urethane component, that is, the structural unit derived from the polyester polyol in the structural unit (100% by weight) derived from the polyol (total polyol) in the urethane acrylic resin (A). Although content is not specifically limited, From a viewpoint of the adhesive improvement of the printing layer of this invention, and a base material (especially polyester-type film), 80 weight% or more (80-100 weight%) is preferable, More preferably, 90 % By weight (90 to 100% by weight).

  The ratio of urethane component (content of urethane component) to acrylic component (content of acrylic component) [urethane component: acrylic component] (weight ratio) in the urethane acrylic resin (A) is 1: 9 to 9: 1. Is more preferable, and 3: 7 to 7: 3 is more preferable. When [urethane component: acrylic component] is less than 1: 9, the adhesion between the printed layer and the substrate may be lowered. On the other hand, when the [urethane component: acrylic component] is less than 9: 1, the acrylic component is likely to be blocked, and the printability at the time of forming the printing layer may be reduced (plate fog is likely to occur).

  The content of the structural unit derived from the monomer having the (meth) acryloyl group in the urethane acrylic resin (A) (100% by weight) is not particularly limited, but is preferably 10 to 90% by weight, more preferably. Is 30 to 70% by weight. When the content is less than 10% by weight, the acrylic component in the urethane acrylic resin (A) is small and blocking is likely to occur, or the printability at the time of forming the printing layer is reduced (plate fog is likely to occur). There is. On the other hand, if the content exceeds 90% by weight, the urethane component in the urethane acrylic resin (A) is small, and the adhesion between the printing layer and the substrate (particularly the polyester film) may be lowered.

  Analysis / measurement of the constituent units (monomer components) constituting the urethane acrylic resin (A), acrylic resin (B) and lactone polymer (E) and the content of the constituent units are not particularly limited. For example, it can be performed by nuclear magnetic resonance (NMR), gas chromatograph mass spectrometer (GCMS) or the like.

  The glass transition temperature (Tg) of the urethane acrylic resin (A) is not particularly limited, but is preferably −30 to 100 ° C., more preferably 0 to 70 ° C. from the viewpoint of improving scratch resistance and ink crack resistance. It is. In the present specification, Tg can be measured by, for example, DSC (differential scanning calorimetry). The DSC measurement is not particularly limited. For example, the DSC measurement can be performed using a differential scanning calorimeter “DSC6200” manufactured by Seiko Instruments Inc. under a temperature rising rate of 10 ° C./min.

  The weight average molecular weight (Mw) of the urethane acrylic resin (A) is not particularly limited, but it is improved in shrinkage followability (followability of the print layer against shrinkage deformation during shrink processing), the print layer and the substrate of the present invention. From the viewpoint of improving the adhesion and preventing blocking, 20000 to 100000 is preferable, 25000 to 80000 is more preferable, and 30000 to 60000 is more preferable. In the present specification, Mw can be measured, for example, by gel permeation chromatography (GPC).

  Although the acid value of the said urethane acrylic resin (A) is not specifically limited, From a viewpoint of the storage stability (coagulation inhibitory property of a pigment (especially titanium oxide)) of the printing ink which forms the printing layer of this invention, 0- 20 mgKOH / g is preferable, More preferably, it is 0.3-5 mgKOH / g. In addition, in this specification, an acid value is calculated | required based on JISK5601-2-1 (titration method).

  A commercial item can also be used for the said urethane acrylic resin (A). For example, “Acryt 8UA-140” and “Acryt 8UA-357” manufactured by Taisei Fine Chemical Co., Ltd. are available on the market.

(Acrylic resin (B))
The acrylic resin (B) is not particularly limited, and a known or common acrylic resin for printing ink can be used. Although the said acrylic resin (B) is not specifically limited, The role as a main resin component which forms the printing layer of this invention is borne. As the acrylic resin (B), a polymer composed of an acrylic monomer as an essential monomer component, that is, a polymer (copolymer) having at least a structural unit derived from a monomer having a (meth) acryloyl group. Can be mentioned. The monomer component constituting the acrylic resin (B) may contain a monomer component other than the monomer having a (meth) acryloyl group, but the monomer component constituting the acrylic resin (B) is (meth). It preferably consists of only a monomer having an acryloyl group.

  The acrylic resin (B) does not include the acrylic resin corresponding to the component (A) or the component (E). That is, the acrylic resin (B) excludes an acrylic resin having a urethane bond in the molecule, and an acrylic resin containing a structural unit derived from a lactone compound and a phosphate group in the molecule.

Examples of the monomer having the (meth) acryloyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, ( Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) (Meth) acrylic acid alkyl ester having a linear or branched alkyl group such as isononyl acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate [preferably C _1-12 alkyl (meth) acrylate Esters etc.]; (Meth) acrylic acid; carboxyl groups such as carboxyethyl acrylate (Meth) acrylic acid ester; 2-hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 6-hydroxyhexyl (meta) ) Hydroxyl group-containing (meth) acrylic acid ester such as acrylate, diethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate [preferably (meth) acrylic acid hydroxy C _1-8 alkyl ester etc.]; (Meth) acrylic acid cycloalkyl esters such as cyclohexyl acrylate; N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-di (Meth) acrylic acid amide derivatives such as til (meth) acrylamide; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, dipropylamino And (meth) acrylic acid dialkylaminoalkyl esters such as propyl (meth) acrylate. The monomer which has the said (meth) acryloyl group can be used individually or in combination of 2 or more.

  Although it does not specifically limit as a monomer component which comprises acrylic resin (B) other than the monomer which has the said (meth) acryloyl group, For example, carboxyl group containing polymeric properties, such as crotonic acid, itaconic acid, fumaric acid, and maleic acid Unsaturated compounds or anhydrides thereof; styrenic compounds such as styrene, vinyltoluene, and α-methylstyrene; vinyl esters such as vinyl acetate and vinyl propionate; vinyl halides such as vinyl chloride; vinyl ethers such as methyl vinyl ether; Examples include cyano group-containing vinyl compounds such as (meth) acrylonitrile; ethylene, propylene and the like.

  Among the above, the acrylic resin (B) is a group consisting of methyl methacrylate, ethyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, isobutyl methacrylate, ethyl acrylate, butyl acrylate and methacrylic acid. An acrylic resin having a structural unit derived from a monomer having a more selected (meth) acryloyl group as a main structural unit is particularly preferable.

  Content of monomer having (meth) acryloyl group in total amount (100% by weight) of monomer component constituting acrylic resin (B), that is, (meth) in acrylic resin (B) (100% by weight) The content of the structural unit derived from the monomer having an acryloyl group is not particularly limited, but is 80% by weight or more (80 to 100%) from the viewpoint of the adhesion between the printing layer of the present invention and the substrate (particularly polyester film). % By weight), more preferably 90% by weight or more (90 to 100% by weight).

  Although the weight average molecular weight (Mw) of the said acrylic resin (B) is not specifically limited, From a viewpoint of the improvement of the adhesiveness of the printing layer of this invention, and a base material, the improvement of printability, and blocking prevention, it is 10,000-150,000. Is more preferable, 20000 to 80000, more preferably 30000 to 60000.

  The glass transition temperature (Tg) of the acrylic resin (B) is not particularly limited, but is preferably 30 to 105 ° C. from the viewpoint of improving scratch resistance, heat resistance and ink crack resistance of the printing layer of the present invention. More preferably, it is 40-80 degreeC.

  The acid value of the acrylic resin (B) is preferably 1 to 40 mgKOH / g from the viewpoint of the storage stability of the printing ink for forming the printing layer of the present invention (aggregation inhibition of pigment (particularly titanium oxide)), More preferably, it is 2-20 mgKOH / g.

  A commercial item can also be used for the said acrylic resin (B). For example, “ARUFON series” manufactured by Toagosei Co., Ltd. and “Dianar series (BR series, LR series, etc.)” manufactured by Mitsubishi Rayon Co., Ltd. are available on the market.

(Cellulose resin (C))
The cellulose resin (C) is not particularly limited, and a known or commonly used cellulose resin for printing ink can be used. As the cellulose resin (C), for example, esterified cellulose resins such as nitrocellulose (nitrified cotton), cellulose acetate butyrate (CAB), cellulose acetate, and cellulose acetate propionate (CAP) are preferable. These can be used alone or in combination of two or more. Among these, cellulose acetate butyrate (CAB) and nitrocellulose are particularly preferable.

  The cellulose-based resin (C) is not particularly limited, but the effect of adjusting the viscosity of a resin composition for forming a printing layer (sometimes referred to as “printing ink”) and imparting hardness to the printing layer. Demonstrate the effect. In the case where the viscosity of the printing ink is low, it is preferable to increase the viscosity by adding the cellulose resin (C) because the coating property (coating property) can be improved.

  Although the weight average molecular weight of the said cellulose resin (C) is not specifically limited, 10,000-150,000 are preferable, More preferably, it is 20,000-100,000. If the weight average molecular weight is less than 10,000, the viscosity of the printing ink may not increase. On the other hand, if it exceeds 150,000, the solubility of the cellulose resin may deteriorate. Further, a stringing phenomenon may occur during gravure printing, which is not preferable.

  A commercial item can also be used for the said cellulose resin (C). For example, “CAB-381-20, CAB-381-0.5, CAB-551-0.1” manufactured by Eastman Chemical Co., “HIG Series”, “LIG Series” manufactured by Bergerac NC are available on the market. Is possible.

(Pigment (D))
The said pigment (D) is not specifically limited, The well-known thru | or usual pigment used for printing inks can be used. Although the said pigment (D) is not specifically limited, it plays the role which gives a color to the printing layer of this invention. Examples of the pigment (D) include inorganic pigments and organic pigments. Examples of the inorganic pigment include titanium oxide (white pigment), carbon (black pigment / black pigment), pearl pigment, metal (silver pigment), and more specifically, for example, titanium oxide (titanium dioxide), Oxides such as bengara; sulfates such as barium sulfate (eg, precipitated barium sulfate); carbonates such as calcium carbonate (eg, precipitated calcium carbonate); silicates such as hydrous silicate and anhydrous silicate; aluminum powder And metal powders such as aluminum flakes, carbon black, and pearl pigments. Examples of the organic pigment include azo pigments and polycyclic pigments. Examples of the azo pigment include azo lake (soluble azo) pigments such as carmine 6B (PR-57) and red 2B (PR-48); monoazo yellow (PY-1, PY-3), disazo yellow (PY-12, PY). -13, PY-14, PY-17, PY-83), pyrazolone orange (PO-13, PO-34), insoluble azo pigments such as Vulcan orange (PO-16); Chromophthalo Yellow (PY-93, PY) -95) and condensed azo pigments such as chromophthaled red (PR-144, PR-166). Examples of the polycyclic pigment include phthalocyanine pigments such as copper phthalocyanine blue (PB-15, PB-15: 1, PB-15: 3) and copper phthalocyanine green (PG-7); dioxazine violet (PV -23) and the like; isoindolinone yellow pigments such as isoindolinone yellow (PY-109, PY-110); and selenium pigments such as perylene, perinone, flavantron, and thioindigo. Among these, as the pigment (D), titanium oxide is preferable.

  The said titanium oxide is not specifically limited, The well-known thru | or usual titanium oxide (titanium dioxide) used for printing inks can be used. Examples of the titanium oxide include rutile type (tetragonal high temperature type), anatase type (tetragonal low temperature type), and brookite type (orthorhombic type) titanium oxide. Further, the titanium oxide may be a titanium oxide surface-treated with at least one selected from the group consisting of alumina, silica, zinc, and zirconium.

  The average particle diameter (average particle diameter) of the titanium oxide (in the case where an aggregate is formed, the particle diameter of the aggregate, so-called secondary particle diameter) is not particularly limited, but is, for example, 0.1 to 1 μm. Is preferable, more preferably 0.1 to 0.5 μm, and still more preferably 0.2 to 0.4 μm. If the average particle size is less than 0.1 μm, the titanium oxide particles may not be scraped off by the doctor during printing, and printing defects (so-called “fogging”) may occur, and the white density is low. Therefore, the concealment may be reduced. On the other hand, when the thickness exceeds 1 μm, titanium oxide particles are likely to settle in the printing ink, and the storage stability (also referred to as storage stability) of the printing ink may be reduced. In this case, the white density also decreases. There is.

  A commercial item can also be used for the pigment (D). For example, a titanium oxide “JR series (JR-809, JR-708, JR-707, etc.)” manufactured by Teika Corporation is available.

(Lactone polymer (E))
The lactone polymer (E) is a polymer containing a structural unit derived from a lactone compound and a phosphate group. That is, the lactone polymer (E) is a polymer that contains at least one phosphate group in the molecule and is composed of a lactone compound as an essential raw material component. The lactone polymer (E) improves the printability (printability of printing ink) of the printing layer of the present invention.

  Examples of the lactone polymer (E) include a homopolymer of a lactone compound containing a phosphate group; a copolymer of two or more lactone compounds containing a phosphate group; Examples thereof include a copolymer of a lactone compound and a compound other than the lactone compound. More specifically, as the lactone polymer (E), for example, a polymer containing a phosphate group, a polymer having a polylactone chain as a main chain (polylactone containing a phosphate group); A copolymer having a polylactone chain and a polyether chain; a copolymer having a phosphate group and having a polylactone chain and a polyacryl chain (an acrylic copolymer having a structural unit derived from a lactone compound and a phosphate group) Polymer).

  When the lactone polymer (E) is a copolymer, the form of copolymerization is not particularly limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. The lactone polymer (E) may be a copolymer containing a molecular chain composed of a lactone compound (polylactone chain) in the main chain, or a molecular chain composed of a lactone compound (polylactone). It may be a copolymer containing a chain) in the side chain.

  The lactone compounds (lactones) are not particularly limited and include known or commonly used lactones (γ-lactone, δ-lactone, etc.). Among them, as the lactone compound, for example, γ-pentalactone, γ-caprolactone, δ-valerolactone, δ-caprolactone, and ε-caprolactone (2-oxepanone) are preferable. The lactone compounds can be used alone or in combination of two or more.

  Although it does not specifically limit as compounds other than a lactone type compound used as a raw material component which comprises the said lactone type polymer (E), The monomer, polyol compound, etc. which have a (meth) acryloyl group are mentioned. These can be used alone or in combination of two or more.

Examples of the monomer having the (meth) acryloyl group include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, ( Isobutyl acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, (meth) (Meth) acrylic acid alkyl ester having a linear or branched alkyl group such as isononyl acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate [preferably C _1-12 alkyl (meth) acrylate Esters etc.]; (Meth) acrylic acid; carboxyl groups such as carboxyethyl acrylate (Meth) acrylic acid ester; 2-hydroxymethyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 6-hydroxyhexyl (meta) ) Hydroxyl group-containing (meth) acrylic acid ester such as acrylate, diethylene glycol mono (meth) acrylate, dipropylene glycol mono (meth) acrylate [preferably (meth) acrylic acid hydroxy C _1-8 alkyl ester etc.]; (Meth) acrylic acid cycloalkyl esters such as cyclohexyl acrylate; aromatic (meth) acrylates such as phenyl (meth) acrylate, benzyl (meth) acrylate, and phenoxyethyl (meth) acrylate; N (Meth) acrylic acid amide derivatives such as methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (meth) acrylamide, N, N-diethyl (meth) acrylamide; dimethylaminoethyl (meth) And (meth) acrylic acid dialkylaminoalkyl esters such as acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, dimethylaminopropyl (meth) acrylate, and dipropylaminopropyl (meth) acrylate. . Among these, as a monomer having a (meth) acryloyl group, a (meth) acrylic acid alkyl ester having a linear or branched alkyl group [in particular, a (meth) acrylic acid C _1-12 alkyl ester], ( Preferred are (meth) acrylic acid and aromatic (meth) acrylate, and more preferred are methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate and benzyl methacrylate.

  The polyol compound is not particularly limited. For example, ethylene glycol, diethylene glycol, 1,3-propanediol, propylene glycol (1,2-propanediol), butanediol (1,3-butanediol, 1,4- Butanediol, etc.), low molecular weight glycols such as 1,6-hexanediol and cyclohexanedimethanol; known diols such as polyether diols such as polyethylene glycol, polypropylene glycol and polytetramethylene glycol, and trifunctional or higher functional polyols Examples thereof include compounds (such as polyether polyols).

  The lactone polymer (E) has at least one phosphate group in the molecule.

  The lactone polymer (E) may have an amino group from the viewpoint of improving the adsorptivity to the pigment (D) (particularly titanium oxide).

  The weight average molecular weight (Mw) of the lactone polymer (E) is not particularly limited, but is from 300 to 10,000 from the viewpoint of preventing the lactone polymer (E) from bleeding out and improving the dispersibility of the pigment (D). Preferably, it is 500-5000.

  Although the acid value of the said lactone type polymer (E) is not specifically limited, 10-150 mgKOH / g is preferable, More preferably, it is 15-100 mgKOH / g. When the acid value is less than 10 mgKOH / g, the adsorptivity of the lactone polymer (E) to the pigment (D) (particularly titanium oxide) is lowered, and the dispersibility of the pigment (D) may be lowered. On the other hand, when the acid value exceeds 150 mgKOH / g, the pigment (D) (particularly titanium oxide) tends to aggregate in the printing ink, and the storage stability of the printing ink may be lowered. In addition, printability may be reduced.

  The amine value of the lactone polymer (E) is not particularly limited, but is preferably 0 to 50 mgKOH / g, more preferably 0 to 30 mgKOH / g, from the viewpoint of dispersibility of the pigment (D).

  A commercial item can also be used for the lactone polymer (E). For example, “DISPERBYK-111” and “DISPERBYK-2001” manufactured by BYK-Chemie are available on the market.

(Additive)
The printing layer of the present invention contains components (additives) other than component (A), component (B), component (C), component (D) and component (E) within a range not impairing the effects of the present invention. You may contain. Although it does not specifically limit as said additive, Resin other than a component (A), a component (B), a component (C), and a component (E), dye, a plasticizer, a lubricant, an anti-settling agent, a dispersing agent, a stabilizer , Curing agents, antifoaming agents, fillers, antioxidants, ultraviolet absorbers, antistatic agents, anti-coloring agents, fragrances, deodorants and the like. The said additive can be used individually or in combination of 2 or more.

  Examples of the lubricant include polyolefin waxes such as polyethylene wax and polyethylene oxide wax, various waxes (waxes) such as fatty acid amide, fatty acid ester, paraffin wax, polytetrafluoroethylene (PTFE) wax, carnauba wax, and the like. Can be mentioned.

  Content (namely, content of component (A), component of said specific resin (urethane acrylic resin (A), acrylic resin (B), and cellulose resin (C)) in the printing layer of this invention The total amount of the content of (B) and the content of component (C) is preferably 5 to 50% by weight, more preferably based on the total weight (100% by weight) of the printing layer of the present invention. Is 10 to 40% by weight, more preferably 20 to 30% by weight. When the content of the specific resin is less than 5% by weight, the adhesion between the printed layer and the substrate may be lowered, and particularly, the scratch resistance and the rub resistance may be lowered.

In the printing layer of the present invention, the total weight of the specific resin [that is, the total weight (total weight) of the urethane acrylic resin (A), the acrylic resin (B), and the cellulose resin (C)] (100 wt%) The content of the urethane acrylic resin (A) is preferably 4 to 40% by weight, more preferably 5 to 30% by weight, and still more preferably 6 to 20% by weight. Further, the content of the acrylic resin (B) with respect to the total weight (100% by weight) of the specific resin is preferably 40 to 96% by weight, more preferably 55 to 95% by weight, and further preferably 70 to 94% by weight. It is.
When the content of the urethane acrylic resin (A) is less than 4% by weight or when the content of the acrylic resin (B) exceeds 96% by weight, the printing layer and the substrate (particularly the polyester film substrate) In some cases, the peel resistance may decrease before and after shrink processing, or the print layer may be easily peeled off during the manufacture, processing and distribution of the shrink label. In addition, the scratch resistance of the printing layer may be reduced, and the shrink label surface may be easily damaged. Further, the printed layer becomes brittle, the resistance to padding is lowered, and the printed layer may be easily cracked or peeled off during shrink processing or distribution.
On the other hand, when the content of the urethane acrylic resin (A) exceeds 40% by weight, the printed layer becomes too soft, and the printed layer at the seal portion is pulled during the shrink processing, and is easily broken into vertical streaks. , Shrinkability may be reduced. In addition, printing ink may be expensive and disadvantageous in cost. In addition, plate fog is likely to occur during printing.

  In the printing layer of the present invention, the content of the cellulose resin (C) with respect to the total weight (100% by weight) of the specific resin is preferably 0 to 20% by weight, more preferably 0 to 15% by weight, and still more preferably. Is 3 to 10% by weight. If the content of the cellulose-based resin (C) exceeds 20% by weight, the adhesion between the printed layer and the substrate is lowered, and particularly the peel resistance is deteriorated. There is a case where peeling of the printed layer is likely to occur. In addition, the printing ink may have a too high viscosity and the coating property may deteriorate.

  Although content of the pigment (D) in the printing layer of this invention is not specifically limited, 5-90 weight% is preferable with respect to the total weight (100 weight%) of the printing layer of this invention. In particular, when the pigment (D) is titanium oxide, the content of titanium oxide in the printed layer of the present invention is not particularly limited, but from the viewpoint of concealability and printability, the total amount of the printed layer of the present invention is not limited. 30-90 weight% is preferable with respect to a weight (100 weight%), More preferably, it is 40-80 weight%, More preferably, it is 50-70 weight%.

  In the printing layer of the present invention, the content of the lactone polymer (E) is 1 to 20 parts by weight with respect to the total weight (100 parts by weight) of the specific resin, and 1.3 to 15 parts by weight. preferable. When content of the said component (E) is less than 1 weight part, the printability of a printing layer may fall. On the other hand, when the content of the component (E) exceeds 20 parts by weight, the pigment (D) (particularly titanium oxide) aggregates.

  The content of the lubricant (especially wax) in the printing layer (100% by weight) of the present invention is not particularly limited, but is preferably 0.1 to 10% by weight, more preferably 2 to 7% by weight. .

  The thickness of the printing layer of the present invention is not particularly limited, but is preferably 0.5 to 5 μm, more preferably 1 to 4 μm, from the viewpoint of wear resistance and concealment.

[Base material]
The base material in the shrink label of the present invention serves as a support for the printed layer, and has a major influence on the strength, rigidity and shrinkage characteristics of the label. Although the said base material is a shrink film (heat-shrinkable film) and is not specifically limited, The shrink film used as a base material of a well-known shrink label can be used. The type of resin that forms the shrink film can be appropriately selected according to the required physical properties, application, cost, and the like, and is not particularly limited. For example, a polyester resin, a polyolefin resin, a polystyrene resin, Examples of the resin include polyvinyl chloride resin, polyamide resin, aramid resin, polyimide resin, polyphenylene sulfide resin, and acrylic resin. These resins may be used alone or in combination of two or more. Furthermore, the same kind or different kinds of resins may be laminated to be used as a laminated film. Of these, polyester resins, polyolefin resins, and polystyrene resins are preferable. That is, the shrink film includes a polyester film made of a polyester resin, a polystyrene film made of a polystyrene resin, a polyolefin film made of a polyolefin resin, a polyester resin as an outer layer, and a polyolefin resin or a polystyrene resin as an inner layer. The heterogeneous laminated film is preferred. Among the above, a polyester film is particularly preferable from the viewpoint of transparency. The printed layer of the present invention also exhibits excellent adhesion to a base material of a polyester film whose adhesion is likely to be lowered with respect to general printing inks and printing layers. Examples of the polyester-based resin, polyolefin-based resin, and polystyrene-based resin include, for example, JP-A-2008-170822, JP-A-2008-170697, JP-A-2008-163215, and JP-A-2008-163231. The polyester resins, polyolefin resins, polystyrene resins, and the like described can be used.

  As the polyester resin used for the polyester film, polyethylene terephthalate (PET) resin, poly (ethylene-2,6-naphthalenedicarboxylate) (PEN), polylactic acid (PLA), and the like can be used. Among them, polyethylene terephthalate (PET) resin is preferable. As the PET resin, polyethylene terephthalate (PET) using terephthalic acid as the dicarboxylic acid component and ethylene glycol as the diol component; terephthalic acid as the dicarboxylic acid component, ethylene glycol as the diol component, Copolyester (CHDM copolymerized PET) using 4-cyclohexanedimethanol (CHDM) as a copolymerization component, terephthalic acid as a dicarboxylic acid component, ethylene glycol as a main component as a diol component, neopentyl glycol (NPG) as a main component Copolyester (NPG copolymerized PET) used as copolymer component, terephthalic acid as dicarboxylic acid component, ethylene glycol as main component as diol component, diethylene glycol as copolymer component Diol-modified PET, such as copolymerized polyester; (in the dicarboxylic acid component, modified terephthalic acid as a main component with isophthalic acid and / or adipic acid) the dicarboxylic acid-modified PET, and the like.

  As a polystyrene-type resin used for the said polystyrene-type film, as a constituent monomer, for example, styrene, α-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, p-isobutylstyrene, pt- Examples thereof include resins containing one or more styrene monomers such as butyl styrene and chloromethyl styrene. Specifically, for example, general polystyrene, styrene-butadiene-styrene copolymer (SBS), styrene-butadiene / isoprene-styrene copolymer (SBIS), styrene-acrylate copolymer, and the like are preferably exemplified. .

  Polyolefin resins used for the polyolefin film include polyethylene resins such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), and metallocene catalyst LLDPE (mLLDPE), polypropylene, and propylene-α-olefin. Examples include polypropylene resins such as copolymers, ethylene-vinyl acetate copolymers, and cyclic olefin resins. In particular, the polyolefin film is preferably one having a cyclic olefin resin as an outer layer. For example, it is preferable to use a cyclic olefin resin as an outer layer and a polyethylene resin or a polypropylene resin as an inner layer (center layer).

  The substrate in the present invention may have a single layer configuration or may have a laminated configuration. That is, the shrink film may be a single layer film or a laminated film in which a plurality of film layers are laminated according to required physical properties, applications, and the like. In the case of a laminated film, film layers made of the same kind of resin may be laminated, or film layers made of different resins may be laminated. In the case of a laminated film, a laminated film having a polyester resin as an outer layer and a polyolefin resin or polystyrene resin as an inner layer, or a laminated film having a cyclic olefin resin as an outer layer and a polyethylene resin or a polypropylene resin as an inner layer is preferable.

  The shrink film used as the substrate is preferably a uniaxially, biaxially or multiaxially oriented film from the viewpoint of exhibiting shrinkage characteristics. When the shrink film is a laminated film, it is preferable that at least one film layer in the laminated film is oriented. When all the film layers are non-oriented, sufficient shrink characteristics may not be exhibited. As the shrink film, a uniaxial or biaxially oriented film is particularly preferable, and among them, a film that is strongly oriented in the uniaxial direction of the film (substantially uniaxially stretched film) is more preferable. A film uniaxially stretched in the width direction is particularly preferable.

  The shrink film can be produced by a conventional method such as melt film formation or solution film formation. It is also possible to use a commercially available shrink film. The surface of the shrink film may be subjected to conventional surface treatment such as corona discharge treatment or primer treatment, if necessary. When a shrink film having a laminated structure is produced, a conventional method such as a co-extrusion method or a dry lamination method can be used as a lamination method. Biaxial stretching in the longitudinal direction (the film production line direction; also referred to as the longitudinal direction or MD direction) and the width direction (the direction perpendicular to the longitudinal direction; also referred to as the transverse direction or TD direction) is used as a method for orienting the shrink film. Further, uniaxial stretching or the like in the longitudinal direction or the width direction can be used. As the stretching method, for example, a roll method, a tenter method, a tube method, or the like can be used. For example, the stretching treatment of the film substantially uniaxially stretched in the width direction is, for example, 1.01 to 1.5 times, preferably 1.05 in the longitudinal direction at a temperature of about 70 to 100 ° C., if necessary. The film can be stretched by about 3 to 6 times, preferably about 4 to 5.5 times in the width direction after stretching about 1.3 times.

  The shrinkage rate of the shrink film in the main orientation direction at 90 ° C. for 10 seconds (sometimes referred to as “thermal shrinkage rate (90 ° C., 10 seconds)”) is not particularly limited, but is 15 to 90%. Preferably, it is 20 to 85%. Although the thermal contraction rate (90 degreeC, 10 second) of the direction orthogonal to the main orientation direction of the said shrink film is not specifically limited, -3-10% is preferable. The above-mentioned “main orientation direction” is a direction mainly subjected to a stretching process (a direction having the largest thermal shrinkage), and is generally a longitudinal direction or a width direction, for example, substantially in the width direction. In the case of a uniaxially stretched film, it is the width direction.

  When the shrink film is a transparent film, the haze value (%) of the shrink film (based on JIS K 7105) is preferably less than 10%, more preferably less than 5.0%, and still more preferably less than 2.0%. . When the haze value is 10% or more, when printing is shown through the shrink film, the printing may become cloudy and the decorativeness may be deteriorated.

  Although the thickness of the said base material is not specifically limited, 10-100 micrometers is preferable, More preferably, it is 12-80 micrometers, More preferably, it is 15-60 micrometers. When the substrate thickness is thin (for example, about 10 to 45 μm), details are unknown, but generally, the crystallinity of the substrate is increased during film formation, and thus the adhesion between the printed layer and the substrate is low. Although it tends to decrease, the printed layer of the present invention is preferable because it can exhibit excellent adhesion even to such a thin substrate, that is, a so-called thin substrate (particularly a thin polyester film).

  A commercial item can also be used for the shrink film used as the substrate. For example, “Space Clean S7042” and “SV-808” manufactured by Toyobo Co., Ltd. “LX-10S” and “LX-61S” manufactured by Mitsubishi Plastics Co., Ltd. (hereinafter polyester film); CI Kasei Co., Ltd. “Bonset” manufactured by Gunze Co., Ltd. “GMLS” manufactured by Gunze (polystyrene film); “FL” manufactured by Gunze Co., Ltd. (polyolefin film); “Ecology” manufactured by Mitsubishi Plastics Co., Ltd. (polylactic acid film) ); “DL” manufactured by Mitsubishi Resin Co., Ltd., “HGS” manufactured by Gunze Co., Ltd. (a laminated film having a polyester resin as a surface layer and a polystyrene resin as a central layer).

[Shrink label]
The shrink label of the present invention has the printed layer of the present invention on at least one side of the substrate. The printed layer of the present invention may be provided on the entire surface of the shrink label surface, or may be provided only on a part of the surface of the shrink label. Even if the printed layer of the present invention is provided directly on the substrate without using another layer such as an anchor coat layer, sufficient adhesion can be exhibited. For this reason, it is advantageous in terms of productivity and cost. In addition, the printing layer of this invention may be provided on the base material through the anchor coat layer as needed.

  The print layer of the present invention is used as a design print layer (color print layer, white print layer, etc.) such as a figure, a design, or a background.

  Furthermore, in the shrink label of the present invention, in addition to the base material and the printed layer of the present invention, other than the adhesive layer, the ultraviolet protection layer, the print protective layer, the anchor coat layer, the primer coat layer, and the printed layer of the present invention. You may provide layers, such as a printing layer (it may call an "other printing layer"), a nonwoven fabric, paper, as needed.

In the shrink label of the present invention, the printed layer of the present invention may be provided so as to be inside the label, or may be provided so as to be outside the label.
The laminated structure of the shrink label of the present invention is not particularly limited. For example, from the front side (the front side of the label), the substrate / the printed layer of the present invention, and the two-layer laminated structure of the printed layer / substrate of the present invention; Examples of the multi-layer structure include a printing layer of the invention / a substrate / a printing layer of the invention.

  In the present specification, the “front side” of the shrink label means the side viewing the design of the label (the side of the surface on which the design looks correct), and the “back side” of the shrink label means the above “front side”. Means the other side. The “outside” of the shrink label means the side that does not contact the container (the side opposite to the container) when the shrink label is attached to the container, and the “inside” of the shrink label contacts the container. Means side (container side).

  The shrinkage rate of the shrink label of the present invention in the main orientation direction at 90 ° C. for 10 seconds (thermal shrinkage rate (90 ° C., 10 seconds)) is not particularly limited, but is 15% or more (for example, 15 to 90%). ) Is preferable, and more preferably 20 to 85%. When the heat shrinkage (90 ° C., 10 seconds) is less than 15%, the followability with respect to the shape of a container or the like to which the label is attached is insufficient during shrink processing, and a beautiful finish may not be obtained. Although the thermal contraction rate (90 degreeC, 10 second) of the direction orthogonal to the main orientation direction of the shrink label of this invention is not specifically limited, -3-10% is preferable. The “main orientation direction” is a direction mainly subjected to a stretching process (a direction having the largest thermal shrinkage rate), and is generally a circumferential direction when the shrink label is a cylindrical shrink label.

In the shrink label of this invention, acrylic resin (B) is used as a resin component which forms the printing layer of this invention. For this reason, it is relatively safe. Furthermore, since the printing layer of this invention contains urethane acrylic resin (A), it has high adhesiveness with a base material, and also has moderate softness | flexibility. Therefore, the shrink label of the present invention is difficult to peel off the printed layer, and is excellent in the resistance to scratching and scratch of the printed layer. Therefore, it is possible to use a polyester-based film, particularly a thin (thin) polyester-based film, which is safe and easily deteriorates in adhesion to a general printing layer. In addition, the printed layer of the present invention can be provided on various types of substrates such as polyester, polystyrene, and polyolefin, and various thicknesses. In other words, the shrink label of the present invention is based on The type and thickness of the material can be widely changed, and it has excellent versatility.
In addition, the toughness of the printing layer increases due to the effect of the printing layer becoming flexible, so there is no problem of cracking the printing layer and blowing powder on the guide in the label manufacturing and processing processes, and productivity is improved. To do.

However, when a printing ink containing a urethane acrylic resin contains a pigment (particularly when it contains titanium oxide), the coating (coating) property tends to be insufficient. As a result, the printing ink The printing layer formed from the above tends to have insufficient printability, and in particular, expressiveness such as design of gradation (gradation) expression tends to be insufficient.
On the other hand, this invention improved the printability of the printing layer by adding a specific lactone polymer (E). The lactone polymer (E) in the present invention contains a structural unit derived from a lactone compound and a phosphate group in the molecule. As a result, the phosphoric acid group moiety has an adsorptivity to the pigment (particularly titanium oxide), and the structural unit part (polylactone moiety, etc.) derived from the lactone compound has an affinity for the specific resin. Although it is considered to improve the dispersibility of the pigment in the printing ink and the printing layer, the coating property of the printing ink and the printing property of the printing layer of the present invention are improved. For this reason, the printing layer of the present invention is excellent in expressiveness such as a design of gradation expression while containing a pigment.

  Thereby, the shrink label of the present invention has both the adhesion between the substrate and the printing layer and the printing property of the printing layer at a high level while having a printing layer containing a pigment (particularly titanium oxide).

  Although the shrink label of this invention is not specifically limited, such as a cylindrical label and a winding label, it is a cylindrical shrink label (cylindrical shrink label) from a viewpoint which is excellent in design property (decorative property) and followability with respect to a container shape. Is preferred.

  Although the shrink label of this invention is not specifically limited, It mounts | wears with containers, such as a container for drinks, and is used as a container with a label. In addition, the shrink label of this invention may be used for adherends other than a container.

  By placing the shrink label of the present invention (particularly the cylindrical shrink label of the present invention) on the container by arranging and heat shrinking the front side to be opposite to the container, A labeled container having a shrink label) is obtained. Examples of the containers include soft drink bottles such as PET bottles, milk bottles, food containers such as seasonings, alcoholic beverage bottles, pharmaceutical containers, detergents, chemical product containers such as sprays, and cup noodle containers. included. Although it does not specifically limit as a shape of the said container, For example, various shapes, such as bottle types, such as cylindrical shape and a square shape, and a cup type, are mentioned. The material of the container is not particularly limited, and examples thereof include plastic such as PET, glass, and metal.

[Shrink label manufacturing method and processing method]
Examples of the shrink label manufacturing method and processing method (cylindrical shrink label processing method) of the present invention are shown below.
The resin composition (printing ink) for forming the printing layer of the present invention includes the specific resin (urethane acrylic resin (A), acrylic resin (B), and, if necessary, cellulose resin (C). ), The pigment (D), the lactone polymer (E), and a solvent, and, if necessary, an additive. Mixing can be performed by a known and common 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, homomixer, homodisper, or roll mill , Sand mills, ball mills, bead mills, line mills, kneaders and the like are used. The mixing time (retention time) during mixing is not particularly limited, but is preferably 10 to 120 minutes.

  In order to control the content of each component (component (A), (B), (C), (D), (E), etc.) in the printing layer of the present invention, The printing ink may be prepared so that the content of each of the components becomes a desired content in the printing layer. In general, the content (% by weight) of each component (nonvolatile content) in the total nonvolatile content of the printing ink is equal to the content (% by weight) of each component in the printing layer of the present invention of the shrink label. Become.

  As said solvent, the organic solvent etc. which are normally used for printing inks, such as gravure printing and flexographic printing, etc. can be used, for example, acetates, such as ethyl acetate, propyl acetate, butyl acetate; methanol, ethanol, isopropyl alcohol, Alcohols such as propanol and butanol; Ketones such as methyl ethyl ketone and methyl isobutyl ketone; Aromatic hydrocarbons such as toluene and xylene; Aliphatic hydrocarbons such as hexane and octane; Alicyclic carbonization such as cyclohexane and methylcyclohexane Hydrogens; glycols such as ethylene glycol and propylene glycol; glycol ethers such as ethylene glycol monopropyl ether, propylene glycol monomethyl ether and propylene glycol monobutyl ether; B propylene glycol monomethyl ether glycol ether esters such as acetate, etc. are exemplified. Among these, acetates and alcohols are preferable from the viewpoints of solubility and safety. The said solvent can be used individually or in mixture of 2 or more types. The solvent can be removed by drying after applying the printing ink to the substrate. The solvent (solvent) includes the meaning of “dispersion medium”.

  The viscosity (23 ± 2 ° C.) of the printing ink is not particularly limited. For example, in the case of coating by gravure printing, 10 to 1000 mPa · s is preferable, and 20 to 500 mPa · s is more preferable. When the viscosity exceeds 1000 mPa · s, for example, the gravure printability is lowered, and “blur”, “plate fog”, etc. may occur, and printing may not be performed as desired. In addition, when the viscosity is less than 10 mPa · s, the storage stability is deteriorated, for example, the pigment and the additive are easily settled, or “span” occurs, resulting in uneven printing, and printing according to the desired design. May not be possible. The viscosity of the printing ink can be controlled by the type and blending amount (content) of a specific resin and other components, a thickener, a thinning agent, and the like. In particular, the addition of the cellulose-based resin (C) is preferable because the viscosity can be easily controlled within an appropriate range. In the present specification, “viscosity” is JIS Z 8803 under the conditions of 23 ± 2 ° C. and cylinder rotation speed of 50 rpm using an E-type viscometer (conical flat plate rotational viscometer) unless otherwise specified. The value measured according to.

  Next, the printing ink of the present invention is provided by applying and drying the printing ink on the surface of the substrate (shrink film), and the shrink label of the present invention can be produced. The above coating and drying steps may be performed during the shrink film manufacturing process (in-line coating) or after the shrink film formation (off-line coating), but from the viewpoint of productivity and workability An off-line coat is preferred. Moreover, you may provide layers other than the printing layer of this invention as needed.

  As a method for applying the printing ink, a gravure printing method, a flexographic printing method, and a letterpress printing method are preferable from the viewpoints of cost, productivity, printing decoration, and the like, and a gravure printing method is particularly preferable. Moreover, when drying the applied printing ink layer (application layer) by heating or the like, a general heating device capable of heating on the printing device can be preferably used. From the viewpoint of safety, a hot air heater or the like can be preferably used.

  The shrink label may be processed into a cylindrical label. For example, the shrink label is formed in a cylindrical shape so that the main orientation direction is the circumferential direction. Specifically, a shrink label having a predetermined width in the main orientation direction is formed into a cylindrical shape by overlapping both ends in the main orientation direction so that the outer surface (outside) of the shrink label is on the front side, and one side of the label Apply a solvent or adhesive such as tetrahydrofuran (THF) or an adhesive (hereinafter referred to as an adhesive) on the inner surface at a width of about 2 to 4 mm on the edge, and apply the adhesive or the like to the outer surface of the other side edge. To obtain a cylindrical shrink label. In addition, it is preferable that the printing layer is not provided in the part which apply | coats said adhesive agent etc., and the part to adhere | attach.

  In addition, when providing the perforation for label cutting to a cylindrical shrink label, the perforation of predetermined length and a pitch is formed in the direction orthogonal to the circumferential direction. The perforation can be applied by a conventional method (for example, a method of pressing a disk-shaped blade having a cut portion and a non-cut portion repeatedly formed around it, a method using a laser, or the like). The process stage for perforating can be appropriately selected after the printing process and before and after the cylindrical processing process.

  The cylindrical shrink label can be attached to a container to form a labeled container. For example, after a cylindrical shrink label is externally fitted to a predetermined container, the label is thermally contracted by heat treatment, and a container with a label is manufactured by closely contacting the container. Examples of the heat treatment include treatment with steam at 80 to 100 ° C. (passing through a heating tunnel filled with steam and steam). In addition, it is preferable that the shrink label of this invention is mounted | worn with the container so that the printing layer of this invention may become an inner side.

  EXAMPLES Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples.

Table 1 shows the blending composition (blending amount) of the printing ink used in Examples and Comparative Examples, the content of the specific resin in the printing ink and the printing layer, the urethane acrylic resin and the acrylic resin relative to the total weight of the specific resin. , A cellulose resin, a structural unit derived from a lactone compound and a polymer containing a phosphate group (a lactone polymer containing a phosphate group), a dispersant other than a lactone polymer containing a phosphate group ( The content of the non-volatile content), the evaluation result of the obtained shrink label, and the like are shown.
The blending composition of the above printing ink is indicated by the blending amount (parts by weight) based on the weight of the product used. In addition, the content of the specific resin in the printing layer (equal to the content of the specific resin in the non-volatile content of the printing ink) is the urethane acrylic resin and acrylic resin in the printing layer (in the total non-volatile content of the printing ink). And the total content of cellulose resin (nonvolatile content) (% by weight). Furthermore, the content of the dispersant other than urethane acrylic resin, acrylic resin, cellulose resin, lactone polymer containing phosphate groups, and lactone polymer containing phosphate groups with respect to the total weight of the specific resin is The content in terms of nonvolatile content (parts by weight or% by weight).
The urethane acrylic resin and acrylic resin described above do not include dispersants (a) to (e).

  Table 2 shows details of products (resins etc.) used for printing ink.

Further, Table 3 shows the types and structures of resins contained in the urethane acrylic resin solution (made by Taisei Fine Chemical Co., Ltd., trade name “Acryt 8UA-140”) used as the urethane acrylic resin (a). The compound (monomer component constituting the resin) derived from the constituent unit constituting and the weight percentage (ratio in the resin) of each constituent unit], the acid value and the weight average molecular weight are shown. Moreover, the solvent composition (a kind and content rate of a solvent) and non-volatile content concentration of the said solution were shown. In addition, the structure of said resin was measured by < ¹ > H-NMR analysis and thermal decomposition analysis. ¹ H-NMR analysis was performed under the following conditions using NMR (500 MHz) [manufactured by JEOL Ltd., “JNM-LA500”]. In addition, pyrolysis analysis was performed by gas chromatograph mass spectrometer [manufactured by Shimadzu Corporation, “GCMS-QP2010”], medium polarity column [manufactured by Restek, “Rtx-200”], and micropolar column [manufactured by Frontier Lab. , “UltraALLOY-5”] and a portable pyrolyzer [manufactured by Japan Analytical Industries, Ltd., “JCI-22”].
^<1 H-NMR analysis conditions>
EXMOD (measurement method): non (measure in a state in which the influence of hydrogen nuclei remains)
OBNUC (observation nucleus): ¹ H
IRNUC (irradiation nucleus): ¹ H
CTEMP (set temperature): 22.9 ° C
SLVNT (measurement solvent): CDCl ₃ (deuterated chloroform)

Example 1
(Printing ink)
As urethane acrylic resin (a), urethane acrylic resin solution (manufactured by Taisei Fine Chemical Co., Ltd., trade name “Acryt 8UA-140”, nonvolatile content concentration: 40% by weight) 2 parts by weight (as urethane acrylic resin, 0 .8 parts by weight) was used. As shown in Table 3, the urethane acrylic resin solution (Acryt 8UA-140) was neopentyl glycol 8.1% by weight, ethylene glycol 3.3% by weight, terephthalic acid 12.9% by weight, isophthalic acid 12 9.9% by weight, isophorone diisocyanate 17.2% by weight, n-butyl methacrylate 30.9% by weight, methyl methacrylate 14.7% by weight as a monomer component (compound derived from the structural unit), A polyester diol urethane acrylic resin solution having a weight average molecular weight of 40,000 and an acid value of 2.5 mgKOH / g (solvent: mixed solvent of 99% by weight of ethyl acetate and 1% by weight of isopropyl alcohol, non-volatile content: 40% by weight) is there.
As the acrylic resin (a), 10 parts by weight of an acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd., trade name “Dianar BR-113”, nonvolatile concentration: 100% by weight) was used.
As the acrylic resin (b), 2 parts by weight of an acrylic resin (manufactured by Mitsubishi Rayon Co., Ltd., trade name “Dianar BR-116”, nonvolatile concentration: 100 wt%) was used.
As the cellulose resin, 0.5 part by weight of CAB resin (manufactured by Eastman Chemical Co., Ltd., trade name “CAB-381-20”, nonvolatile content concentration: 100% by weight) was used.
As titanium oxide (pigment), 37 parts by weight of titanium oxide (manufactured by Teika Co., Ltd., trade name “JR-707”, nonvolatile content concentration: 100% by weight) was used.
As a dispersant (a), a lactone polymer solution containing a phosphate group (BYK-Chemie (BIC Chemie), trade name “DISPERBYK-111”, nonvolatile content concentration: 95% by weight) 0.2 parts by weight (0.19 parts by weight as a lactone polymer containing a phosphate group) was used.
The urethane acrylic resin (a), acrylic resin (a), acrylic resin (b), cellulosic resin, titanium oxide, dispersant (a), anti-settling agent (manufactured by Ito Oil Co., Ltd., product) Name “ASA-TS-021”, non-volatile content: 20% by weight) 0.5 part by weight, wax (manufactured by Sasol, trade name “SPRAY105”, non-volatile content: 100% by weight) 2 parts by weight, ethyl acetate 9 A printing ink (100.2 parts by weight) was prepared by adding 13 parts by weight of n-propyl acetate, 5 parts by weight of propyl cellosolve and 19 parts by weight of isopropyl alcohol (IPA).
The urethane acrylic resin content is 6.0% by weight and the acrylic resin content is based on the total weight (100% by weight) of the specific resin (urethane acrylic resin, acrylic resin and cellulose resin) in the printing ink. The amount was 90.2% by weight, and the content of cellulosic resin was 3.8% by weight. In addition, the content of the lactone polymer containing a phosphate group with respect to the total weight (100 parts by weight) of the specific resin in the printing ink was 1.4 parts by weight.
In addition, the ratio of content of each resin and polymer in said printing ink is equal to the ratio of content of each resin and polymer in the printing layer of a shrink label.

(Shrink label)
Polyester (PET) shrink film (trade name “SV808”, manufactured by Toyobo Co., Ltd., thickness: 30 μm, heat shrinkage ratio in main orientation direction (width direction) (90 ° C., 10 seconds): 50%) on one side, using a gravure plate with an engraving of 70 lines / inch, the entire surface is subjected to gravure printing, dried using a hot air dryer at 50 ° C. to form a printed layer, and a shrink label is obtained. It was. The thickness of the printed layer after drying was about 3 μm.
The base material was a polyester (PET) shrink film (Mitsubishi Resin Co., Ltd., trade name “LX-61S”, thickness: 45 μm, heat shrinkage in the main orientation direction (width direction) (90 ° C., 10 seconds). ): 81%) A shrink label was obtained in the same manner as above except that the content was changed to 81%). The thickness of the printed layer after drying was about 3 μm.

Examples 2 to 4, Comparative Example 3
As shown in Table 1, printing inks and shrink labels were produced in the same manner as in Example 1 except that the amount of the lactone polymer (dispersant) containing a phosphate group was changed.

Example 5
As shown in Table 1, printing inks and shrink labels were produced in the same manner as in Example 1 except that the type and blending amount of the lactone polymer (dispersant) containing a phosphate group were changed.

Comparative Example 1
As shown in Table 1, a printing ink and a shrink label were produced in the same manner as in Example 1 without using a urethane acrylic resin and a dispersant containing a lactone polymer containing a phosphate group.

Comparative Example 2
As shown in Table 1, printing inks and shrink labels were produced in the same manner as in Example 1 without using a dispersant containing a lactone polymer containing a phosphate group.

Comparative Examples 4-6
As shown in Table 1, Example 1 was carried out using a dispersant containing a compound other than a lactone polymer containing a phosphate group without using a dispersant containing a lactone polymer containing a phosphate group. In the same manner, printing ink and shrink label were prepared.

(Evaluation)
For the shrink labels obtained in the examples and comparative examples, the peel resistance (tape peel test), scratch resistance (scratch test), flaw resistance (fir test), shrink suitability (ink crack test), main orientation direction The thermal shrinkage rate (90 ° C., 10 seconds) was evaluated and tested by the following method.
The tape peel test (peeling resistance), scratch test (scratch resistance), and fir tree test (fir resistance) are based on the product name “SV808” (thin type PET film) manufactured by Toyobo Co., Ltd. For the ink cracking test (shrink suitability), a shrink label based on the product name “LX-61S” (high shrinkage type PET film) was used for the ink cracking test (shrink suitability). .
Moreover, the tape peeling test (peeling resistance), the scratch test (scratch resistance), and the fouling test (fir resistance) were tested on shrink labels immediately after production.

(1) Peel resistance (tape peel test)
The test was conducted in accordance with JIS K 5600-5-6 except that no cross cuts were made on the grid. An adhesive tape having a width of 18 mm (manufactured by Nichiban Co., Ltd., trade name “Cello Tape (registered trademark))” is pasted on the surface of the printed layer of the shrink label obtained in Examples and Comparative Examples. Peeled in the direction.
In the area of 5 mm (longitudinal direction; orthogonal direction to the main orientation direction) × 5 mm (width direction; main orientation direction) in the surface of the printed layer with the adhesive tape attached, the remaining area (ratio) of the print layer was visually observed. And judged according to the following criteria.
The remaining area of the printed layer is 90% or more. : Good peel resistance (○)
The remaining area of the printed layer is 80% or more and less than 90%. : Peeling resistance is slightly poor but usable (△)
The remaining area of the printed layer is less than 80%. : Poor peel resistance (×)

(2) Scratch resistance (scratch test)
Samples for measurement measuring 100 mm (longitudinal direction; orthogonal direction to the main orientation direction) × 100 mm (width direction; main orientation direction) were collected from the shrink labels obtained in the examples and comparative examples. Place the sample for measurement on a smooth table, observe the surface after rubbing the surface on the side where the printed layer was provided 10 times in the back of the nail of the hand (20 mm in the longitudinal direction). Judged by criteria.
The printed layer is not peeled at all. : Good scratch resistance (○)
Partial peeling is observed on the printed layer. : Scratch resistance is slightly poor but usable level (△)
The printed layer is peeled off significantly. : Scratch resistance failure (×)

(3) Scratch resistance (scratch test)
Samples for measurement measuring 100 mm (longitudinal direction; orthogonal direction to the main orientation direction) × 100 mm (width direction; main orientation direction) were collected from the shrink labels obtained in the examples and comparative examples. Hold both ends of the sample for measurement with both hands, and even 10 times. The remaining area (ratio) of the printed layer on the surface provided with the printed layer was visually observed and evaluated according to the following criteria.
The remaining area of the printed layer is 90% or more. : Good resistance to cracking (○)
The remaining area of the printed layer is 80% or more and less than 90%. : Slightly poor resistance to wear, but usable level (△)
The remaining area of the printed layer is less than 80%. : Poor resistance to cracking (×)

(4) Shrinkability (ink cracking test)
From the shrink labels obtained in Examples and Comparative Examples, a measurement sample of 110 mm (longitudinal direction; direction orthogonal to the main orientation direction) × 210 mm (width direction; main orientation direction) was collected. After making the measurement sample into a cylindrical shape so that the main orientation direction of the measurement sample (the main orientation direction of the shrink film) is the circumferential direction, and the surface on the side where the printing layer is provided is inside, the both ends are overlapped The overlapping portions were joined by heat welding to obtain a cylindrical shrink label (peripheral length: 200 mm).
A cylindrical glass bottle having a diameter of 62 mm (circumferential length of 194 mm) and a height of 108 mm was prepared. Furthermore, 110 mm (longitudinal direction; perpendicular direction to the main orientation direction) × 10 mm (width direction; main orientation direction) shrink film (trade name “LX-61S”, manufactured by Mitsubishi Plastics, Inc., thickness: 45 μm) I prepared a strip.
The strips were aligned so that the width direction (main orientation direction) was the circumferential direction of the cylindrical glass bottle, and the upper and lower ends of the strip and the upper and lower ends of the cylindrical glass bottle were fixed with cellophane adhesive tape (upper and lower ends). The strip and the cylindrical glass bottle are not bonded at the center of the strip, except for). Next, the cylindrical shrink label is placed over the cylindrical glass bottle (with strips) so that the printed layer faces the strip, and immersed in hot water at 90 ° C. for 20 seconds to heat the shrink label. Shrinkage (the strip also thermally shrinks in the width direction at this time) to obtain a labeled container.
Observe the appearance (outside) of the label of the container with the label, peel off the cylindrical shrink label, observe the inside of the label, and crack the ink along the strip (stripe ink in the height direction of the container) It was visually observed whether or not peeling occurred. Evaluation was made according to the following criteria.
No ink cracks are seen from the outside or from the inside after peeling off the label. : Good shrinkability (○)
Even when observed from the outside, no ink cracks are seen, but when the label is peeled off, ink cracks are seen inside the label. : Shrinkability is slightly poor but usable level (△)
Ink cracks are seen from the outside. : Shrinkability failure (×)

(5) Thermal shrinkage in main orientation direction (90 ° C., 10 seconds)
A rectangular measurement sample having a length of 200 mm (mark interval 150 mm) and a width of 10 mm in the measurement direction (main alignment direction) was cut out from the shrink labels obtained in Examples and Comparative Examples.
The measurement sample is heat-treated for 10 seconds (under no load) in hot water at 90 ° C., the difference between the marked lines before and after the heat treatment is read, and the heat shrinkage rate is calculated by the following formula.
Thermal shrinkage (%) = (L ₀ −L ₁ ) / L ₀ × 100
L ₀ : Marking interval before heat treatment L ₁ : Marking interval after heat treatment In the examples and comparative examples, the main orientation direction is the width direction of the shrink label.
Further, the thermal contraction rate (90 ° C., 10 seconds) in the direction orthogonal to the main alignment direction can be measured in the same manner as described above by changing the measurement direction to the direction orthogonal to the main alignment direction.

  Using the printing inks obtained in the examples and comparative examples, the printability and the storage stability of the printing ink were tested and evaluated by the following methods.

(6) Printability (gradation expression)
(Gradation expression before shrink processing)
The printing inks obtained in the examples and comparative examples were printed on one side of a PET-based shrink film (manufactured by Toyobo Co., Ltd., trade name “SV808”, thickness: 30 μm) with a gradation plate [manufactured by Custom Gravure Co., Ltd., Using gravure 70 lines / cm, angle 0], gravure printing was performed at a process speed of 200 m / min, and drying was performed at 50 ° C. using a hot air dryer to obtain a shrink label.
The gradation plate has a color density of 100%, 50%, 20%, and 5%.
The printed part (gradation printed part) of the shrink label obtained above was visually observed and evaluated according to the following criteria.
The printing ink has been transferred (printed) to the shrink film up to the 20% color density (at least 100%, 50%, 20%). : Good printability (gradation expression) (○)
The printing ink is not transferred to the shrink film in the portion having the color density of 20%, but the printing ink is transferred to the shrink film up to the portion having the color density of 50%. : Printability (gradation expression) is slightly poor but usable (△)
The printing ink is not transferred to the shrink film even at the portion where the color density is 50%. : Printability (gradation expression) failure (×)

(Gradation expression after shrink processing)
From the above-obtained shrink label (shrink label including a gradation printed portion), a label piece including a gradation printed portion [100 mm (longitudinal direction; perpendicular direction to the main orientation direction) × 150 mm (width direction; main orientation direction) ] Was cut out. The label piece was fixed to a jig capable of fixing a portion having a length of 100 mm in the main orientation direction (width direction) of the label piece at an interval of 70 mm. (It is in a slack state before shrink processing.) The label piece fixed to the jig was treated by immersing it in hot water at 90 ° C. for 20 seconds and thermally contracted by 30% in the main orientation direction (shrink treatment). In this way, a label piece thermally contracted by 30% in the main orientation direction was obtained.
The printed part (gradation printed part) of the label piece that was shrink-treated by the above method and thermally contracted by 30% in the main orientation direction was visually observed and evaluated according to the following criteria.
The printing ink has been transferred (printed) to the shrink film up to the 20% color density (at least 100%, 50%, 20%). : Good printability (gradation expression) (○)
The printing ink is not transferred to the shrink film in the portion having the color density of 20%, but the printing ink is transferred to the shrink film up to the portion having the color density of 50%. : Printability (gradation expression) is slightly poor but usable (△)
The printing ink is not transferred to the shrink film even at the portion where the color density is 50%. : Printability (gradation expression) failure (×)

(7) Storage stability of printing ink (titanium oxide aggregation suppression)
The printing inks obtained in Examples and Comparative Examples were allowed to stand in a polypropylene bottle for 1 week at room temperature (23 ° C.). Thereafter, the properties of the printing ink were observed and evaluated according to the following criteria.
There is no aggregation and sedimentation of titanium oxide. : Good storage stability (○)
Reversible aggregation or sedimentation of titanium oxide occurs. : Stable storage stability but usable level (△)
Irreversible aggregation or sedimentation of titanium oxide occurs. : Storage stability failure (×)

As can be seen from the evaluation results, the shrink labels (Examples) of the present invention are excellent in the adhesion between the printed layer and the substrate while using an acrylic resin as the main resin component for forming the printed layer, and have good resistance to resistance. It had releasability, resistance to scratching, scratch resistance, and shrinkability (inhibition of ink cracking during shrink processing). Furthermore, it was a shrink label excellent in the printability of the print layer (particularly the expression of gradation printing).
On the other hand, when no urethane acrylic resin was added to the printing layer (Comparative Example 1), the adhesion between the printing layer and the substrate was lowered, and the peel resistance was poor. In the case where a structural unit derived from a lactone compound and a polymer containing a phosphate group (a lactone polymer containing a phosphate group) are not added to the printing layer (Comparative Examples 2, 4 to 6), The printability of the printing ink and the printing layer was lowered. Furthermore, when the content of the lactone polymer containing a phosphoric acid group in the printing ink and the printing layer is too large (Comparative Example 3), the pigment (titanium oxide) tends to aggregate and the storage stability of the printing ink is increased. And the peel resistance of the printed layer was lowered.
In addition, the thermal contraction rate (90 degreeC, 10 second) of the main orientation direction of the shrink label (a base material is SV808 thing) obtained by the Example and the comparative example is 50%, and a shrink label (a base material is LX-). The heat shrinkage rate (90 ° C., 10 seconds) in the main alignment direction was 81%.

Claims (4)

At least one side of the substrate includes a urethane acrylic resin, an acrylic resin, a pigment, and a polymer containing a structural unit derived from a lactone compound and a phosphate group, and further includes or does not include a cellulose resin. Having a printing layer,
Content of the polymer containing the structural unit derived from the lactone compound and the phosphate group with respect to 100 parts by weight of the total weight of the urethane acrylic resin, the acrylic resin, and the cellulose resin in the printed layer. A shrink label, wherein 1 to 20 parts by weight.   The content of the urethane acrylic resin is 4 to 40% by weight with respect to the total weight of 100% by weight of the urethane acrylic resin, the acrylic resin, and the cellulose resin in the printing layer, and the acrylic resin is contained. The shrink label according to claim 1, wherein the amount is 40 to 96% by weight and the content of the cellulose resin is 0 to 20% by weight. The printing layer contains a solvent, a urethane acrylic resin, an acrylic resin, a pigment, and a polymer containing a structural unit derived from a lactone compound and a phosphate group, or a solvent, a urethane acrylic resin, an acrylic. A coating ink containing a structural resin derived from a resin, a pigment, a lactone compound and a phosphoric acid group, and a printing ink containing a cellulose resin was applied to the surface of the substrate and dried. The shrink label according to claim 1, which is a printed layer. The shrink according to any one of claims 1 to 3, wherein the pigment is titanium oxide, and the content of titanium oxide is 30 to 90% by weight with respect to the total weight (100% by weight) of the printed layer. label.