JP2008170697A - Plastic label and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic label excellent not only in productivity but also in adhesiveness between printing layers, scratch resistance and rubbing resistance of label surface. <P>SOLUTION: On at least one side of a plastic film, a printed layer A printed with a solvent ink in which a binder resin is a resin not containing nitrogen atoms having an unshared electron pair is formed and, on the surface of the printed layer A, a printed layer B printed with a cationic polymerizable active energy ray curing type ink is formed without depending on another layer. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a plastic label and a manufacturing method thereof. More specifically, the present invention relates to a plastic label having a printing layer made of a solvent type ink and a printing layer made of a non-solvent type active energy ray curable ink and a method for producing the same.

  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. In many cases, these containers are coated with a resin composition such as an ink or a coating agent for the purpose of displaying the contents and imparting various functions such as decorativeness, scratch resistance, and slipperiness. A plastic label made of a plastic film (a so-called shrink label or stretch label) is attached. From the viewpoint of rich design and expressiveness, the above coating is usually performed by gravure printing or flexographic printing, and is mainly performed by overprinting of color ink and white ink or color ink and transparent ink. It has become.

  Conventionally, for gravure printing, solvent-based inks in which a binder resin and pigment are dissolved and dispersed in an organic solvent are used from the viewpoints of handleability such as pigment dispersibility, printability such as productivity, design, and expression. It has been. However, these solvent-based inks are not preferable in terms of environment because they use an organic solvent, and the cost of recovering and decomposing the solvent is large. For this reason, it is required to reduce the amount of the solvent-based ink used.

  As a method for solving this problem, a method using a water-based ink that does not use an organic solvent or uses a small amount of an organic solvent, or a printing that reduces the amount of solvent-based ink used in combination with a solvent-based ink and a water-based ink. A method is known (see, for example, Patent Document 1). However, when water-based inks are used, it takes time to dry, so printing speed is slow and productivity is lowered, pigment dispersibility is reduced and usable colors are limited, and water-based inks are also used. Nevertheless, the solvent contains a relatively large amount of alcohol, resulting in a problem that the amount of organic solvent used cannot be reduced sufficiently. Furthermore, both solvent-based inks and water-based inks have insufficient resistance such as solvent resistance, water resistance, oil resistance, and scratch resistance. When these inks are used, the use of labels requires various resistances. It has a problem that it is limited to applications that cannot be performed (for example, beverage applications).

  On the other hand, in the field of flexographic printing, active energy ray curable inks such as ultraviolet rays are the mainstream, and radical polymerizable or cationic polymerizable active energy ray curable inks are used. According to these active energy ray curable inks, printing was possible without using an organic solvent, and further, there was an advantage that various resistances were excellent.

  However, the radically polymerizable active energy ray-curable ink has a problem that it cannot be used in the food field such as beverages because of the odor of the initiator and unreacted monomer contained in the ink. In addition, when used as a shrink label, there is a problem in that the ink follows the shrinking process and is inferior, and thus ink peeling or shrinkage whitening occurs.

  According to the cationic polymerizable active energy ray curable ink, although the above-mentioned problems due to odor can be solved, the printability is poor due to the high viscosity, the expression of the printed matter, the designability, etc. are not satisfied. Since it is expensive compared with the ink of No. 1, there was a problem that it was disadvantageous in terms of cost.

  As described above, the present situation is that a plastic label that can reduce the use of an organic solvent and satisfy various durability and printability at a low cost has not yet been obtained.

Japanese Patent No. 2951936

  In order to solve the above problem, the present inventors further provided a printing layer formed by coating a cationic polymerizable active energy ray-curable ink on a printing layer formed by applying a solvent-type ink, thereby providing a solvent. We have developed plastic labels that reduce both the amount of organic solvent and the amount of organic solvent used, and the cost of using both cationic ink and cationic polymerizable active energy ray-curable ink.

  However, it has been found that when cationically polymerizable active energy ray-curable ink is overprinted on a printing layer made of solvent-based ink, there is a problem that the curability of the active energy ray-curable ink is significantly reduced.

  Therefore, the object of the present invention is to reduce the amount of organic solvent used by overprinting a solvent-type ink and a cationic polymerizable active energy ray-curable ink, and to provide a plastic label excellent in cost and various resistances. In addition, another object of the present invention is to provide a plastic label in which the active energy ray-curable ink has good curability and excellent productivity. Moreover, it is providing the manufacturing method of this plastic label.

  As a result of intensive studies to achieve the above object, the inventors of the present invention formed a printing layer using a solvent-based ink having a resin not containing a nitrogen atom having an unshared electron pair and containing no nitrogen atom as a binder resin. By providing a printing layer with a cationic polymerizable active energy ray curable ink, while maintaining the curability of the cationic polymerizable active energy ray curable ink, all of environmental properties (low solvent usage), cost, and various resistances are maintained. The present inventors have found that an excellent plastic label can be obtained in terms of surface and completed the present invention.

  That is, according to the present invention, a printing layer A is formed on at least one surface of a plastic film by a solvent-based ink using a resin not containing a nitrogen atom having an unshared electron pair as a binder resin, and the surface of the printing layer A Further, the present invention provides a plastic label characterized in that the printing layer B made of a cation polymerizable active energy ray curable ink is formed without any other layers.

  Further, the present invention provides the above plastic label, wherein the resin having no lone pair and not containing a nitrogen atom is at least one resin selected from an acrylic resin, a cellulose resin, a polyester resin, and a vinyl chloride resin. provide.

  Furthermore, the present invention provides the above plastic label, wherein the cationically polymerizable active energy ray curable ink contains an oxetane compound and an epoxy compound.

  Furthermore, the present invention provides the above plastic label, wherein the cationically polymerizable active energy ray-curable ink contains a silicone compound.

  Further, according to the present invention, the weight ratio of the oxetane compound and the epoxy compound in the cationically polymerizable active energy ray-curable ink is 2: 8 to 8: 2, and the silicone compound is further added to the oxetane compound and the epoxy compound in a total amount of 100. The plastic label containing 0.1 to 30 parts by weight with respect to parts by weight is provided.

  Furthermore, the present invention provides the above-mentioned plastic label containing 0.1 to 70% by weight of a pigment in a cationically polymerizable active energy ray-curable ink based on the total weight of the ink.

  Furthermore, the present invention provides the aforementioned plastic label, wherein the plastic label is a shrink label.

  Furthermore, in the present invention, after at least one surface of the plastic film is coated with a solvent-type ink containing a resin not containing a nitrogen atom having an unshared electron pair, an organic solvent, and a pigment, and dried to form the printed layer A Further, a cationic polymerizable active energy ray curable resin and a cationic polymerizable active energy ray curable ink containing a photopolymerization initiator are applied to the surface of the printing layer A, and the active energy ray is cured to form the printing layer B. A method for producing the plastic label is provided.

  Since the plastic label of the present invention uses solvent-based ink only in some printing layers (for example, color printing layers), the amount of solvent-based ink used is reduced, which is excellent in terms of environment. In addition, since a printing layer formed of a cationic polymerizable active energy ray curable ink is provided on the surface of the printing layer made of solvent-based ink, it has excellent surface resistance such as solvent resistance and scratch resistance, and also has a cationic layer. Since the use amount of the polymerizable active energy ray-curable ink is also reduced, the cost can be kept low. Furthermore, by using a specific resin as a binder resin for solvent-based inks, even when these different types of ink are overprinted, the curing of the cationic polymerizable active energy ray-curable ink is not inhibited, and the productivity is excellent. A plastic label is obtained.

  Below, the plastic label of this invention is demonstrated in detail.

  In the plastic label of the present invention, a printing layer (referred to as “printing layer A”) by solvent-based ink is formed on at least one surface side of the plastic film, and further, a cationic layer is formed on the surface of the printing layer A opposite to the plastic film. A printing layer (referred to as “printing layer B”) using a polymerizable active energy ray-curable ink is formed without any other layers. In the above, the printing layer A may be formed on the surface of the plastic film without any other layer, or may be provided via another layer such as an anchor layer. The plastic film, the printing layer A, and the printing layer B may each have a multilayer structure. Furthermore, in addition to the above, the plastic label of the present invention may have other layers such as a coating layer (such as an adhesive layer) and a resin film layer.

[Plastic film]
The plastic label of the present invention has a plastic film layer. The plastic film is a base material layer of the plastic label of the present invention, serves as a carrier for the printing layer, and plays a role of label strength, rigidity and shrinkage characteristics.

  The type of plastic film used for the plastic label of the present invention can be appropriately selected according to the required physical properties, application, cost, etc., and is not particularly limited. For example, polyester resin, polyolefin resin, polystyrene Resins such as resin, polyvinyl chloride resin, polyamide resin, aramid resin, polyimide resin, polyphenylene sulfide resin, and acrylic resin can be used. Among these, polyester resins, polystyrene resins, and polyolefin resins are preferable, and polyester resins are more preferable.

  Examples of the polyester resin include various polyesters composed of a dicarboxylic acid component and a diol component. Examples of the dicarboxylic acid component include terephthalic acid, isophthalic acid, phthalic acid, 5-t-butylisophthalic acid, 4,4′-biphenyldicarboxylic acid, trans-3,3′-stilbene dicarboxylic acid, and trans-4,4. '-Stilbene dicarboxylic acid, 4,4'-dibenzyldicarboxylic acid, 1,4-naphthalenedicarboxylic acid, 1,5-naphthalenedicarboxylic acid, 2,3-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic 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- Aromatic dicals such as diphenoxyethane-4,4′-dicarboxylic acid, diphenyl ether dicarboxylic acid, and substituted products thereof Acid; 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, Aliphatic dicarboxylic acids such as heptadecanedioic acid, octadecanedioic acid, nonadecanedioic acid, icosanedioic acid, docosanedioic acid, 1,12-dodecanedioic acid, and their substitutions; 1,4-decahydronaphthalenedicarboxylic acid, 1,5-decahydronaphthalenedicarboxylic acid, 2,6-decahydronaphthalenedicarboxylic acid, cis-1,4-cyclohexanedicarboxylic acid, trans-1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, and these And alicyclic dicarboxylic acids such as substitution products thereof. These dicarboxylic acid components can be used alone or in combination of two or more.

  Examples of the diol component include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, 1,5-pentanediol, 2,2 -Dimethyl-1,3-propanediol, 1,6-hexanediol, 2-ethyl-2-methyl-1,3-propanediol, 2,2-diethyl-1,3-propanediol, 1,8-octane Aliphatic acids such as diol, 2-ethyl-2-butyl-1,3-propanediol, 2-ethyl-2,4-dimethyl-1,3-hexanediol, 1,10-decanediol, polyethylene glycol, polypropylene glycol Diol; 1,2-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4 Cycloaliphatic diols such as cyclohexanedimethanol, 2,2,4,4-tetramethyl-1,3-cyclobutanediol; 2,2-bis (4′-β-hydroxyethoxydiphenyl) propane, bis (4′- Examples thereof include ethylene oxide adducts of bisphenol compounds such as β-hydroxyethoxyphenyl) sulfone and aromatic diols such as xylylene glycol. These diol components can be used alone or in combination of two or more.

  In addition to the above, the polyester-based resin includes oxycarboxylic acids such as p-oxybenzoic acid and p-oxyethoxybenzoic acid; monocarboxylic acids such as benzoic acid and benzoylbenzoic acid; and polyvalent carboxylic acids such as trimellitic acid. Structural units such as monohydric alcohols such as polyalkylene glycol monomethyl ether; polyhydric alcohols such as glycerin, pentaerythritol and trimethylolpropane may be included.

  The polyester resin used in the present invention is not particularly limited, but terephthalic acid is used as the dicarboxylic acid component, polyethylene terephthalate (PET) using ethylene glycol as the diol component, and 2,6-naphthalenedicarboxylic acid as the dicarboxylic acid component. Poly (ethylene-2,6-naphthalenedicarboxylate) (PEN) using ethylene glycol as the diol component, terephthalic acid as the dicarboxylic acid component, ethylene glycol as the diol component, 1,4- A copolymerized polyester (CHDM copolymerized PET) using cyclohexanedimethanol (CHDM) as a copolymerization component is preferred. From the viewpoint of cost, productivity, etc., PET is particularly preferable. Furthermore, diethylene glycol may be copolymerized from the viewpoint of improving low-temperature shrinkage.

  The above-mentioned polystyrene resin is, for example, styrene, α-methyl styrene, m-methyl styrene, p-methyl styrene, p-ethyl styrene, p-isobutyl styrene, pt-butyl styrene, chloromethyl styrene or the like as a constituent monomer. The resin is not particularly limited as long as it is a resin that contains one or more styrene monomers and exhibits film-forming properties. Examples of such polystyrene resins include general polystyrene (GPPS), which is a homopolymer of styrene, a homopolymer or copolymer of styrene monomers; a mixture of polystyrene and synthetic rubber (for example, polybutadiene or polyisoprene), High impact polystyrene (HIPS) with styrene grafted on synthetic rubber; styrene monomer and conjugated dienes such as butadiene and isoprene, such as styrene-butadiene-styrene (SBS) block copolymer Styrene-conjugated diene copolymer that is a polymer (particularly a block copolymer); Styrene-polymerizable unsaturated carboxylic acid that is a copolymer of a styrene monomer and a (meth) acrylate monomer Acid ester copolymer; styrene-conjugated diene-polymerizable unsaturated carboxylic acid ester copolymer; A rubbery elastic material is dispersed in a continuous phase of a copolymer of a monomer and a (meth) acrylic acid ester monomer, and the copolymer is graft-polymerized on the rubbery elastic material. -High impact polystyrene (graft TIPS) etc. are mentioned.

  Although it does not specifically limit as said polyolefin resin, For example, homopolymers, such as polyethylene (PE), polypropylene (PP), polybutylene, polymethylpentene (PMP); Ethylene-alpha-olefin random copolymer, propylene- Random copolymers such as α-olefin random copolymers; copolymers of cyclic olefins and α-olefins (ethylene, propylene, etc.) or graft modified products thereof, ring-opened polymers of cyclic olefins or hydrogenated products thereof, or Examples thereof include amorphous cyclic olefin polymers such as graft-modified products thereof. Among these, polyethylenes such as low density polyethylene (LDPE), linear low density polyethylene (LLDPE), metallocene catalyst system LLDPE (mLLDPE), and propylene random copolymers such as polypropylene and propylene-α-olefin copolymers. Is preferred. Moreover, these polyolefin resin can be used individually or in mixture of 2 or more types.

  The plastic film of the present invention may be a single layer film, or may be 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 different resins may be laminated. For example, it may be a three-layer laminated film composed of a central layer and a surface layer portion (inner layer, outer layer), a film in which the central layer is composed of a polyolefin resin or a polystyrene resin, and a surface layer is composed of a polyester resin. Moreover, you may use any of an unstretched film, a uniaxially oriented film, and a biaxially oriented film according to a required physical property, a use, etc. In particular, when the plastic label is a shrink label, a uniaxial or biaxially oriented film is often used, and in particular, a film (substantially oriented) in the film width direction (direction that becomes the label circumferential direction). A film uniaxially stretched in the width direction is generally used.

  The plastic 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 plastic film. The surface of the plastic film may be subjected to conventional surface treatment such as corona discharge treatment or primer treatment, if necessary.

  The heat shrinkage rate (90 ° C., 10 seconds) of the plastic film is not particularly limited. For example, in the case of shrink label use, one direction out of the longitudinal direction and the width direction is − 3 to 15% is preferable, and the other direction is preferably 20 to 80%.

  Although the thickness of the said plastic film changes with uses and is not specifically limited, 10-200 micrometers is preferable, for example, in the case of a shrink label use, 20-80 micrometers is preferable, More preferably, it is 30-60 micrometers.

  Commercially available products may be used for the plastic film of the present invention. For example, “Space Clean S7042” manufactured by Toyobo Co., Ltd., “LX-10S” manufactured by Mitsubishi Plastics Co., Ltd. (above, polyester film); Gunze Co., Ltd. ) “GMLS” (polystyrene film); Gunze “FL” (polyolefin film), and the like.

[Print layer A]
A printed layer A is formed on the surface of the plastic film of the present invention by applying solvent-based ink. The printing layer A is preferably used as a so-called color printing layer, and plays a role of displaying a design for decoration, a product name, a product description, a barcode, and the like. The solvent-based ink includes so-called water-based ink containing water as a solvent.

  The solvent-type ink for forming the printing layer A of the present invention contains a binder resin and an organic solvent as essential components. Furthermore, the solvent-based ink preferably contains a colorant.

  The binder resin in the solvent-type ink of the present invention is a resin not containing a nitrogen atom having an unshared electron pair. Examples of such resins include acrylic resins, cellulose resins, polyester resins, and vinyl chloride resins. Among these, from the viewpoint of adhesion (adhesiveness) to a plastic film, an acrylic resin and a cellulose resin are preferable, and an acrylic resin / cellulose resin mixed resin is particularly preferable.

Examples of the monomer component constituting the acrylic resin that is the binder resin include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, (meth ) Butyl acrylate, isobutyl (meth) acrylate, s-butyl (meth) acrylate, t-butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic acid 2 -(Meth) acrylic acid alkyl esters such as ethylhexyl, isononyl (meth) acrylate, decyl (meth) acrylate, dodecyl (meth) acrylate [preferably (meth) acrylic acid C _1-12 alkyl ester, etc.]; Contains carboxyl groups such as (meth) acrylic acid, crotonic acid, itaconic acid, fumaric acid, maleic acid Synthetic unsaturated compounds or anhydrides thereof; 2-hydroxymethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 6-hydroxyhexyl (meth) acrylate, diethylene glycol mono (meth) ) And hydroxyl group-containing (meth) acrylic acid esters [preferably (meth) acrylic acid hydroxy C _1-8 alkyl esters and the like] such as acrylate and dipropylene glycol mono (meth) acrylate.

  In addition to the above, if necessary, (meth) acrylic acid cycloalkyl esters such as cyclohexyl (meth) acrylate; styrene compounds such as styrene, vinyltoluene, α-methylstyrene; vinyl acetate, vinyl propionate, etc. Polymeric unsaturated compounds such as vinyl halides such as vinyl chloride; vinyl ethers such as methyl vinyl ether; olefins such as ethylene and propylene; and dienes can also be used as monomer components.

  As the acrylic resin used in the present invention, “Alfon” manufactured by Toagosei Co., Ltd., “Dianar” manufactured by Mitsubishi Rayon Co., Ltd., “John Krill” manufactured by Johnson Polymer, etc. are commercially available.

  The acrylic resin preferably has a weight average molecular weight of 8000 to 50000, more preferably 9000 to 40000. When the weight average molecular weight is less than 8000, physical properties of the coating such as adhesion and ink cracking are insufficient. On the other hand, when the weight average molecular weight exceeds 50000, the viscosity increases, and a larger amount of a diluting solvent is required when adjusting the viscosity to be appropriate for gravure printing, so that the printability is lowered. In addition, the said weight average molecular weight means the value in the whole acrylic resin. Therefore, when two or more polymers having different monomer compositions are blended and used as the acrylic resin, a polymer having a weight average molecular weight outside the above range can be used, but the weight average molecular weight is within the above range. It is preferable to blend the polymers inside.

  Although the acid value of the said acrylic resin is not specifically limited, The range of 0.1-120 mg-KOH / g is preferable. When the acid value is less than 0.1 mg-KOH / g, the adhesion of the coating film to the polyester film tends to be insufficient, and when it exceeds 120 mg-KOH / g, the alkali resistance of the coating film decreases. It becomes easy. Although the hydroxyl value of acrylic resin is not specifically limited, The range of 0.1-120 mg-KOH / g is preferable. When the hydroxyl value is less than 0.1 mg-KOH / g, the compatibility tends to decrease when mixed with a cellulose resin, and when it exceeds 120 mg-KOH / g, the hot water resistance of the coating film tends to decrease. Become. In addition, said acid value and hydroxyl value mean the value in the whole acrylic resin, respectively. When two or more kinds of polymers having different monomer compositions are blended and used as the acrylic resin, the acid value (or hydroxyl value) of the acrylic resin is the acid value (or hydroxyl value) of each polymer and each It can obtain | require by calculation from the weight ratio of a polymer.

  Although the glass transition temperature (Tg) of the said acrylic resin is not specifically limited, It is preferable that it is the range of 35-80 degreeC. When the glass transition temperature is less than 35 ° C., the physical properties of the printed layer are lowered, and in the case of a shrink label, for example, ink cracking is likely to occur in the shrink process. Further, when the glass transition temperature exceeds 80 ° C., the printability is lowered, and also in this case, ink cracks are liable to occur.

  Preferred examples of the cellulose resin as the binder resin include esterified cellulose resins such as nitrocellulose (nitrified cotton) resin, cellulose acetate butyrate (CAB) resin, cellulose acetate, and cellulose acetate propionate. .

  As said nitrocellulose resin, 10-14% of nitrogen content is preferable, More preferably, it is 10.0-12.5%. The average degree of polymerization of nitrocellulose is preferably in the range of 30 to 100, more preferably 45 to 95. When the average degree of polymerization is less than 30, the effect of adding nitrocellulose is small. When the average degree of polymerization exceeds 100, the viscosity of the solvent-type ink increases, and a larger amount of dilution solvent is required when adjusting to a viscosity suitable for gravure printing. Therefore, the printability tends to decrease.

  As said esterified cellulose resin, it is preferable that 0.5-80% is esterified in the hydroxyl group in resin, More preferably, it is 2-70%. The weight average molecular weight of the esterified cellulose resin is preferably in the range of 12000-75000, more preferably 12000-65000. When the weight average molecular weight is less than 12000, the effect of adding esterified cellulose is small. When the weight average molecular weight exceeds 75,000, the viscosity of the solvent-type ink increases, and a larger amount of dilution solvent is required to adjust the viscosity to be appropriate for gravure printing. Therefore, the printability tends to decrease.

  Moreover, the cellulose resin is preferable because it improves the adhesion (adhesiveness) of the printing layer A to the plastic film, the toughness of the coating film, the hardness, and the ink cracking resistance by mixing with an acrylic resin. In this case, the ratio of the acrylic resin to the cellulose resin is preferably in the range of acrylic resin / cellulose resin (weight ratio) = 50/50 to 99.5 / 0.5, more preferably 60/40. ~ 90/10. When this ratio is lower than 50/50, the adhesion when a polystyrene film is used as the plastic film is insufficient, and when it is higher than 99.5 / 0.5, the adhesion to the polyester film is insufficient. It becomes.

  In the present invention, it is necessary to use a binder resin that does not contain a nitrogen atom having an unshared electron pair as described above. Examples of the structure containing a nitrogen atom having an unshared electron pair include a urethane bond, an amino group, an amide group, and the like. As a resin containing the structure (a resin that cannot be used as a binder resin in the present invention), A typical example is urethane resin. Urethane resin is a resin generally used as a binder resin for gravure printing ink from the viewpoint of adhesion to a plastic film. However, when a resin containing a nitrogen atom having an unshared electron pair is used as a binder resin, the curability of the cationically polymerizable active energy ray-curable ink coated on the resin is markedly lowered. Sufficient productivity cannot be obtained. The details of this cure inhibition mechanism are not clear, but the polymerization reaction (curing reaction) is caused by the coordinate bond between the proton that initiates cationic polymerization generated by irradiation of active energy rays and the lone pair on the nitrogen atom. Is presumed to be partly due to inhibition.

  As the organic solvent in the solvent-type ink of the present invention, solvents usually used for printing inks such as gravure printing and flexographic printing can be used. For example, acetates such as ethyl acetate, propyl acetate, and butyl acetate; methanol Alcohols such as ethanol, isopropyl alcohol, 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; cyclohexane and methylcyclohexane Alicyclic hydrocarbons; glycols such as ethylene glycol and propylene glycol; glycol ethers such as propylene glycol monomethyl ether and propylene glycol monobutyl ether; Such as glycol ether esters such as ether acetate can be exemplified. Among these, acetates and alcohols are preferable from the viewpoints of solubility and safety. An organic solvent can be used individually or in mixture of 2 or more types. The organic solvent can be removed by drying after applying solvent-based ink to a plastic film.

  In order to obtain a color ink, it is preferable to add a colorant such as a dye or a pigment to the solvent-type ink of the present invention. Of these, organic and inorganic color pigments are preferably used from the viewpoint of colorability. Examples of pigments used in solvent-based inks include white pigments such as titanium oxide (titanium dioxide), indigo (blue) pigments such as copper phthalocyanine blue, red pigments such as condensed azo pigments, and yellow pigments such as azo lake pigments. Carbon black, aluminum flakes, mica (mica), etc. can be selected and used according to the application. In addition, extender pigments such as alumina, calcium carbonate, barium sulfate, silica, and acrylic beads can also be used as pigments for the purpose of adjusting gloss.

  The average particle diameter of the pigment (when forming an aggregate, the particle diameter of the aggregate, so-called secondary particle diameter) is, for example, 0.01 to 1 μm, preferably 0.1 to 0.5 μm. Preferably it is 0.15-0.5 micrometer. If the average particle size is less than 0.01 μm, the decorative property may be insufficient. If it exceeds 1 μm, so-called “plate fog” (printing failure due to defective ink scraping of portions other than the image area on the plate) during gravure printing. ) May occur. The content of the pigment can be arbitrarily designed depending on the type of pigment, the concentration of the target color, etc., but is preferably about 0.1 to 70% by weight, more preferably 1 to 50%, based on the total weight of the solvent-based ink. % By weight.

  The solvent-type ink of the present invention is produced by mixing the binder resin (acrylic resin, cellulose resin, etc.), an organic solvent, a colorant and the like. When other additives are used, they are mixed at the same time. Mixing can be carried out using a known and commonly used mixing method, and is not particularly limited.For example, a mixer such as a butterfly mixer, a planetary mixer, a pony mixer, a dissolver, a tank mixer, a homomixer, a homodisper, a roll mill, a sand mill, A mill such as a ball mill, a bead mill, or a line mill, or a kneader is used. The mixing time (retention time) during mixing is preferably 10 to 120 minutes. The obtained ink composition may be used after filtration, if necessary.

  The viscosity (23 ± 2 ° C.) of the solvent-type ink of the present invention is not particularly limited, but is preferably 10 to 2000 mPa · s, more preferably 20 to 1000 mPa · s, for example, when applied by gravure printing. It is. When the viscosity exceeds 2000 mPa · s, the gravure printability may be lowered, and “decrease” or the like may occur, and the decorating property may be lowered. On the other hand, when the viscosity is less than 10 mPa · s, the storage stability may be deteriorated, for example, the pigment or the additive may easily settle. The viscosity of the solvent-type ink can be controlled by the type of binder resin, the amount added, the thickener, the thickener, and the like. In the present specification, “viscosity” is JIS Z unless otherwise specified, using an E-type viscometer (conical plate-type rotational viscometer) under the conditions of 23 ± 2 ° C. and cylinder rotation speed of 50 rotations. The value measured according to 8803 is meant.

  The thixotropy of the solvent-type ink of the present invention is preferably low, and the thixotropic index (TI value) is preferably less than 20, more preferably less than 15, and still more preferably less than 10. When the TI value is 20 or more, the gravure and flexographic printability may decrease, and the productivity may decrease.

  In the present invention, by using the printing layer A as a solvent-type ink, the dispersibility of the pigment is good, the kind of pigment to be added, the degree of freedom of the content is high, and the ink coating property is also good. For this reason, color printing excellent in design is possible. Moreover, since it is cheaper than a cationically polymerizable active energy ray-curable ink, using a solvent-type ink for a part of the printing layer is advantageous in terms of production cost.

[Print layer B]
In the plastic label of the present invention, the printing layer B is formed by applying a cationic polymerizable active energy ray-curable ink on the surface of the printing layer A. The printing layer B is a layer that plays a role such as imparting surface resistance such as solvent resistance and scratch resistance by covering the printing layer A together with roles such as base of color printing display, gloss, matte, etc. Mainly a white print layer, a clear (transparent) print layer, a mat print layer, and the like.

  The cationically polymerizable active energy ray-curable ink for forming the printing layer B of the present invention can be cured by cationic polymerization with active energy rays such as visible light, ultraviolet rays, and electron beams. Of the ink composition. Among the active energy rays, ultraviolet curable and near ultraviolet curable are particularly preferable. A preferable absorption wavelength is 200 to 460 nm.

  Unlike the case of thermosetting, the cationically polymerizable active energy ray-curable ink of the present invention is also suitably used for a substrate that easily deforms due to heat, such as a shrink film. In addition, unlike radically polymerizable inks such as urethane acrylate resins, it has less odor and can be used in a wide range of fields such as beverage applications.

  The cationically polymerizable active energy ray-curable ink of the present invention is only required to have cationic polymerizability and active energy ray-curing property, and known and commonly used cationically polymerizable active energy rays such as epoxy, vinyl ether and oxetane. An ink composition containing a curable resin can be used. Among them, from the viewpoints of curability (curing speed), toughness of the printed layer after curing, and surface resistance, an oxetane compound (hereinafter referred to as component a), epoxy An oxetane / epoxy mixed ink composition containing a compound (hereinafter referred to as component b) as an essential constituent component is preferred. Further, particularly when the ink contains a white pigment, it is preferable to contain a silicone compound (hereinafter referred to as component c) because the curability and the adhesion to the printing layer A are further improved. In addition, the said component a and component b shall not contain the silicone which has an oxetanyl group and an epoxy group.

  When the cationically polymerizable active energy ray-curable ink of the present invention is a colored ink such as a white ink, it is preferable to further contain a colorant such as a pigment in addition to the above components. Moreover, it is preferable to contain a photocationic polymerization initiator (hereinafter referred to as a photopolymerization initiator) in order to exhibit active energy ray curability. Also, for the purpose of imparting other functions, other resin components, sensitizers, dispersants, antioxidants, fragrances, deodorants, stabilizers, lubricants, color separation inhibitors, etc. are impaired. You may add to such an extent that it does not exist.

  The component a is a compound having at least one oxetanyl group in the molecule, and may be either a monomer or an oligomer. For example, oxetane compounds described in JP-A-8-85775 and JP-A-8-134405 can be used, and among them, compounds having one or two oxetanyl groups in one molecule are preferable. As a compound having one oxetanyl group in one molecule, 3-ethyl-3-[(phenoxy) methyl] oxetane, 3-ethyl-3- (hexyloxymethyl) oxetane, 3-ethyl-3- (2- Ethylhexyloxymethyl) oxetane, 3-ethyl-3- (hydroxymethyl) oxetane, 3-ethyl-3- (chloromethyl) oxetane, and the like. Examples of the compound having two oxetanyl groups in one molecule include 1,4-bis [[(3-ethyloxetane-3-yl) methoxy] methyl] benzene, bis [(3-ethyloxetane-3-yl) methyl. ] Ether etc. are mentioned. Among these, 3-ethyl-3- (hydroxymethyl) oxetane and bis [(3-ethyloxetane-3-yl) methyl are particularly preferable from the viewpoint of coating processability and the curability of the coating layer. ] Ether.

  The component a can be produced according to a known method using oxetane alcohol and a halide (for example, xylene dichloride) produced from trimethylolpropane and dimethyl carbonate. In addition, as the component a, an existing oxetane compound may be used. For example, “Aron oxetane OXT-101, 121, 211, 221, 212” manufactured by Toagosei Co., Ltd. is commercially available.

  As the component b, a known epoxy compound having at least one epoxy group in the molecule can be used. For example, an aliphatic epoxy compound, an alicyclic epoxy compound, or an aromatic epoxy compound can be used. Among these, from the viewpoint of high reaction rate, a compound having a glycidyl group or a compound having an epoxycyclohexane ring is preferable, and an epoxy compound having two or more epoxy groups is preferable. For example, examples of the aliphatic epoxy compound include propylene glycol glycidyl ether. Examples of the alicyclic epoxy compound include 3,4-epoxycyclohexylmethyl-3 ', 4'-epoxycyclohexanecarboxylate and bis- (3,4-epoxycyclohexyl) adipate. Examples of the aromatic epoxy compound include bisphenol A glycidyl ether, glycidyl ether condensate of bisphenol A, and epichlorohydrin modified products of novolac resin and cresol resin.

  As the component b, those synthesized by a general method such as synthesis from epichlorohydrin and bisphenol A can be used. For example, “Celoxide 2021”, “Celoxide 2080”, “Epolide” manufactured by Daicel Chemical Industries, Ltd. GT400 "and" UVR6110 "manufactured by Dow Chemical Co., Ltd. are commercially available.

  The compounding ratio (weight ratio) of component a and component b in the cation polymerizable active energy ray curable ink of the present invention is 2: 8 to 8: 2 (component a / component b is 0.25 to 4). Preferably, when coating by gravure or flexographic printing, 4: 6 to 8: 2 (component a / component b is 2/3 to 4) is preferable, and more preferably 5: 5 to 8: 2 (component a / component). b is 1-4). When the amount of the component a is larger than the above range, the ink curing reaction start speed becomes slow, and it takes time for curing, so that productivity may be lowered or uncured in a normal curing process. Further, when the amount of component b is larger than the above range, the viscosity of the ink becomes large and it becomes difficult to apply uniformly by a coating method such as gravure printing or flexographic printing, or the curing reaction is likely to stop. In some cases, the cured product has a low molecular weight, and the printed layer after curing becomes brittle.

  The total amount of the component a and the component b is preferably 30 to 99% by weight with respect to the total amount of the cationic polymerizable active energy ray-curable ink from the viewpoints of coatability and curability. Among these, when the cationic polymerizable active energy ray-curable ink is a clear ink, the content is preferably 60 to 99% by weight, and more preferably 70 to 90% by weight. Further, when the cationic polymerizable active energy ray-curable ink is a colored ink containing a pigment, 30 to 90% by weight is preferable, and when it is a matte ink, 40 to 85% by weight is preferable.

  The silicone compound (silicone oil) as the component c is a polysiloxane having a main chain composed of a siloxane bond, and has a straight silicone compound (dimethyl silicone, methyl phenyl silicone, methyl hydrogen) having no substituent other than methyl group and phenyl group. May be a modified silicone compound having a substituent other than a methyl group or a phenyl group at the side chain or terminal.

  Among the above, the component c is preferably a modified silicone compound from the viewpoint of curability. The silicone used as the base of the modified silicone compound may be a polysiloxane having a main chain composed of a siloxane bond. For example, all side chains, dimethyl silicone having a terminal methyl group, and a phenyl group in a part of the side chain Examples thereof include methylphenyl silicone and methyl hydrogen silicone in which a part of the side chain is hydrogen. Among these, dimethyl silicone is preferable. The bonding position of the substituent in the modified silicone compound is not particularly limited, and has at both ends of the main chain (both ends type: the following structural formula (1)) or one end (one end type: the following structural formula (2)). It may be included in the side chain (side chain type: Structural formula (3) below), and is represented by the following structural formula, for example. Furthermore, you may have a substituent in a side chain and the terminal (both terminal, one terminal).

In the formula, X ¹ and X ² are substituents (other than methyl group and phenyl group). R ¹ , R ² , and R ³ in the formula are hydrogen atoms or hydrocarbon groups, and may contain an oxygen atom, a nitrogen atom, or a sulfur atom. A hydrogen atom, a methyl group, and a phenyl group are preferable, and a methyl group is particularly preferable. Further, m and n in the formula are integers of 1 or more.

  Examples of the substituent in the modified silicone include an epoxy group, a fluorine atom, an amino group, a carboxyl group, an aliphatic hydroxyl group (alcoholic hydroxyl group), an aromatic hydroxyl group (phenolic hydroxyl group), and a (meth) acryloyl group. Examples include a substituent and a substituent containing a polyether chain. Examples of the modified silicone having these substituents include epoxy-modified silicone, fluorine-modified silicone, amino-modified silicone, (meth) acryl-modified silicone, polyether-modified silicone, carboxyl-modified silicone, carbinol-modified silicone, phenol-modified silicone, Examples include diol-modified silicone. Among these, polyether-modified silicone, phenol-modified silicone, and carboxyl-modified silicone are particularly preferable.

  Component c may contain an organic group such as an alkyl group and / or an aralkyl group in addition to the substituents listed above.

なお、式中のＲ⁴、Ｒ⁵は水素原子または炭化水素基であり、酸素原子、窒素原子、硫黄原子を含んでいてもよい。上記エポキシ変性シリコーンにおけるエポキシ基の官能基当量は、硬化性の観点から、３００〜５０００が好ましく、より好ましくは、４００〜４０００である。 When component c of the present invention is an epoxy-modified silicone, the epoxy group as a substituent may be one in which the oxygen atom does not contain a cyclic aliphatic skeleton (left figure: referred to as an aliphatic epoxy group). Alternatively, it may be one in which an oxygen atom of an epoxy group is formed including a cyclic aliphatic skeleton (right figure: referred to as an alicyclic epoxy group).

R ⁴ and R ⁵ in the formula are a hydrogen atom or a hydrocarbon group, and may contain an oxygen atom, a nitrogen atom, or a sulfur atom. From the viewpoint of curability, the functional group equivalent of the epoxy group in the epoxy-modified silicone is preferably 300 to 5000, and more preferably 400 to 4000.

When the component c is a fluorine-modified silicone, the substituent is not particularly limited. For example, a fluorinated alkyl group such as [—R ⁶ CF ₃ ] is preferable. Specifically, —CH ₂ CH ₂ CF _3, such as -C ₃ H ₆ CF ₃ are exemplified. R ⁶ is a hydrocarbon group and may contain an oxygen atom, a nitrogen atom, or a sulfur atom. The fluorine-modified silicone has a viscosity (23 ± 2 ° C.) of preferably 100,000 mPa · s or less, more preferably 50000 mPa · s or less. When the viscosity exceeds 100,000 mPa · s, the viscosity of the ink is increased, and the coatability may be lowered.

When the component c is an amino-modified silicone, the substituent is a substituent containing an amino group and is not particularly limited, but [-R ⁷ NH ₂ ], [—R ⁸ NH—R ⁹ NH ₂ ], An aminoalkyl group represented by [—R ¹⁰ NHC ₆ H ₁₁ ] or the like is preferable, and specific examples include —C ₃ H ₆ NH ₂ , —C ₃ H ₆ NHC ₆ H _{11 and the} like. R ⁷ , R ⁸ , R ⁹ and R ¹⁰ are hydrocarbon groups and may contain an oxygen atom, a nitrogen atom or a sulfur atom. The amino-modified silicone has a viscosity (23 ± 2 ° C.) of preferably 100000 mPa · s or less, more preferably 50000 mPa · s or less. When the viscosity exceeds 100,000 mPa · s, the viscosity of the ink is increased, and the coatability may be lowered. Moreover, the functional group equivalent (unit: g / mol) of amino-modified silicone is 500 or more (for example, 500-60000), More preferably, it is 700-60000. When the functional group equivalent is less than 500, curing inhibition may occur and the curing reaction may not proceed sufficiently. When the functional group equivalent exceeds 60000, the addition effect (adhesion and curing speed improvement) is obtained. There may not be.

When the component c is a (meth) acryl-modified silicone, the substituent is a substituent containing a (meth) acryloyl group, and is not particularly limited, but [-R ¹¹ OCOCH = CH ₂ ], [-R ¹² OCOC (CH ₃ ) ═CH ₂ ] and the like are preferable, and specifically, —C ₃ H ₆ OCOC (CH ₃ ) ═CH ₂ , —C ₃ H ₆ OCOCH═CH _{2 and the} like are exemplified. R ¹¹ and R ¹² are hydrocarbon groups and may contain an oxygen atom, a nitrogen atom, or a sulfur atom. The functional group equivalent (unit: g / mol) of the (meth) acryl-modified silicone is 20000 or less (for example, 50 to 20000), more preferably 100 to 15000. When the functional group equivalent exceeds 20000, the effect of addition may not be obtained.

When the component c is a polyether-modified silicone, the substituent is a substituent containing two or more repeating units containing an ether bond, and is not particularly limited, but [-R ¹³ (C ₂ H ₄ O) _a R ¹⁴ ], [—R ¹⁵ (C ₃ H ₆ O) _b R ¹⁶ ], [—R ¹⁷ (C ₂ H ₄ O) _c (C ₃ H ₆ O) _d R ¹⁸ ], An organic group having a propylene oxide unit as a main component is preferably exemplified. ^{Incidentally, R 13, R 14, R} 15, R 16, R 17, R 18 is a hydrocarbon group, a, b is 6 to 30, c, d is from 1 to 20 approximately an integer. The polyether-modified silicone has a viscosity (23 ± 2 ° C.) of preferably 100000 mPa · s or less, more preferably 50000 mPa · s or less. When the viscosity exceeds 100,000 mPa · s, the viscosity of the ink is increased, and the coatability may be lowered. Moreover, although the HLB value (Hydrophile-Lipophile Balance) of polyether modified silicone is not specifically limited, 0-12 are preferable from a compatible viewpoint, More preferably, it is 0-10. When the HLB value exceeds 12 and the hydrophilicity is high, the compatibility may decrease.

When the component c is carbinol-modified silicone, the substituent is represented by [—R ¹⁹ OH]. Specifically, for example, —C ₃ H ₆ OC ₂ H ₄ OH, —C ₃ H ₆ OH, etc. Is exemplified. In the case of diol-modified silicone, the substituent is

で表されるアルコール性ジオールなどが好ましく、具体的には、

Are preferred, and specifically,

Etc. are exemplified. In the case of phenol-modified silicone, the substituent is represented by, for example, [—R ²⁵ —C ₆ H ₄ —OH], specifically, —C ₂ H ₄ —C ₆ H ₄ —OH, _{-C 3 H 6 -C 6 H 4} -OH and the like. Note that R ¹⁹ , R ²⁰ , R ²¹ , R ²² , R ²³ , and R ²⁵ are aliphatic hydrocarbon groups and may contain an oxygen atom, a nitrogen atom, or a sulfur atom. R ²⁴ is a hydrogen atom, a methyl group, an ethyl group or a propyl group. The hydroxyl value (unit: mg KOH / g) of these aliphatic or aromatic hydroxyl-modified silicones is preferably 5 to 150, more preferably 10 to 140. When the functional group equivalent is less than 5, the effect of addition (particularly adhesion) may not be sufficient, and when it exceeds 150, curing inhibition may occur and the curing reaction may not proceed sufficiently. In addition, although the said hydroxyl value can be measured based on JISK5601-2-1, it calculates from functional group equivalent [functional group equivalent (g / mol) = 56000 / hydroxyl value (mgKOH / g)]. (Especially in the case of phenol-modified silicone).

When the component c is a carboxyl-modified silicone, the substituent is not particularly limited, but is preferably represented by [—R ²⁶ COOH], specifically, for example, —C ₂ H ₄ COOH, — Examples thereof include C ₃ H ₆ COOH. The above R ²⁶ is an aliphatic hydrocarbon group and may contain an oxygen atom, a nitrogen atom, or a sulfur atom. The functional group equivalent (unit: g / mol) of the carboxyl-modified silicone is 6000 or less (for example, 500 to 6000), more preferably 100 to 5000. When the functional group equivalent exceeds 6000, the effect of addition may not be obtained. In addition, the said functional group equivalent is an equivalent of a carboxyl group (COOH part).

  As the component c, commercially available products can be used. For example, as the epoxy-modified silicone, “KF-101, KF-102, KF-105, KF-1001, X-22” manufactured by Shin-Etsu Silicone Co., Ltd. -163A, X-22-163B, X-22-163C, X-22-169AS, X-22-169B, X-22-173DX, X-22-2000 "and the like. As the fluorine-modified silicone, “FL-5, FL-100-100cs, FL-100-450cs, FL-100-1000cs, FL-100-10000cs, X-22-821, X-manufactured by Shin-Etsu Chemical Co., Ltd. 22-822 "," FS1265 "manufactured by Toray Dow Corning Co., Ltd., and the like. Examples of the amino-modified silicone include “KF-8005, KF-859, KF-8008, X-22-3820W, KF-857, KF-8001, KF-861” manufactured by Shin-Etsu Chemical Co., Ltd. As modified silicone, Shin-Etsu Chemical Co., Ltd. "X-22-2426, X-22-164A, X-22-164C, X-22-2404, X-24-8201" (above, methacryl modification), “X-22-2445, X-22-1602” manufactured by Shin-Etsu Chemical Co., Ltd., “TEGO Rad 2400, 2500, 2600, 2700” (manufactured by acrylic modification) manufactured by Degussa Co., Ltd., and the like. As the polyether-modified silicone, “KF-351A, KF-352A, KF-353, KF-354L, KF-355A, KF-615A, KF-945, KF-640, KF-642 manufactured by Shin-Etsu Chemical Co., Ltd. , KF-643, KF-6020, KF-6004, KF-6011, KF-6012, KF-6015, KF-6017, X-22-6191, X-22-4515, X-22-2516 “FZ-2110, FZ-2122, FZ-7006, FZ-2166, FZ-2164, FZ-2154, FZ-2191, FZ-7001, FZ-2120, FZ-2130, FZ-720 manufactured by Dow Corning Co., Ltd. , FZ-7002, FZ-2123, FZ-2104, FZ-77, FZ-2105, FZ-2118, FZ 7604, FZ-2161, FZ-2162, FZ-2203, FZ-2207, FZ-2208, SH-8400, SH-8700, SH-3746, SH-3771, SF-8491 ", and the like. Examples of the carbinol-modified silicone include “X-22-160AS, KF6001, KF6002, KF6003, X-22-4015, X-22-4039, X-22-170DX” manufactured by Shin-Etsu Chemical Co., Ltd., and the like. Examples of the diol-modified silicone include “X-22-176DX, X-22-176D, X-22-176F” manufactured by Shin-Etsu Chemical Co., Ltd. Examples of the phenol-modified silicone include “X-22-1821, X-22-165B” manufactured by Shin-Etsu Chemical Co., Ltd., “BY16-752, BY16-150S” manufactured by Toray Dow Corning Co., Ltd., and the like. As the carboxyl-modified silicone, “X-22-162C, X-22-3701E, X-22-3710” manufactured by Shin-Etsu Chemical Co., Ltd., “BY16-750, BY16-880” manufactured by Toray Dow Corning Co., Ltd. Etc.

  The addition amount of the component c is preferably 0.1 to 30 parts by weight, more preferably 0.2 to 15 parts by weight with respect to the total amount (100 parts by weight) of the component a and the component b. When the amount of component c added is less than 0.1 parts by weight, the effect of component c addition is small, and the curing rate, the adhesion between the printing layer A and the printing layer B, and the toughness of the printing layer B are reduced. There is. In addition, when it exceeds 30 parts by weight, the content of component a or component b is reduced, the curability is lowered, the ink becomes highly viscous, the coating property is lowered, and the printing is blurred. May occur.

  When the cationic polymerizable active energy ray-curable ink of the present invention is used as a colored ink, a colorant such as a pigment can be added. As the coloring agent to be added, the same ones as those of the solvent type ink described above can be used. When the printing layer B is a white printing layer, the cationically polymerizable active energy ray-curable ink is preferably a white printing ink containing a white pigment such as titanium oxide (titanium dioxide). When the printing layer B is a mat layer, it is preferable that the pigment contains extender pigments such as alumina, calcium carbonate, barium sulfate, silica, and acrylic beads from the viewpoint of glossiness.

  The content of the pigment can be arbitrarily designed depending on the type of pigment and the concentration of the target color, but is preferably about 0.1 to 70% by weight, more preferably 1 to 50% by weight based on the total weight of the ink. %.

  When the cationic polymerizable active energy ray curable ink of the present invention is used as a white printing ink, the titanium oxide includes rutile type (tetragonal high temperature type), anatase type (tetragonal low temperature type), brookite type (orthorhombic type). Any of these may be used. For example, titanium oxide particles “Taipeke” manufactured by Ishihara Sangyo Co., Ltd., titanium oxide “JR Series” manufactured by Teika Co., Ltd., etc. are available. Moreover, the average particle diameter of the titanium oxide particles (in the case where an aggregate is formed, the particle diameter of the aggregate, so-called secondary particle diameter) is, for example, 0.01 to 1 μm, preferably 0.1 to 0.00. It is 5 μm, more preferably 0.2 to 0.5 μm. When the average particle size is less than 0.01 μm, the white density is lowered and the concealability is insufficient. If it exceeds 1 μm, so-called “plate fogging” (printing failure due to defective ink scraping of portions other than the image line portion of the plate) occurs during gravure printing. In addition, the content of titanium oxide is preferably 20 to 60% by weight, more preferably 30 to 55%, based on the total weight of the cationic polymerizable active energy ray-curable ink, from the viewpoint of concealability and suppression of coarse protrusion formation. % By weight.

  In the cationically polymerizable active energy ray-curable ink of the present invention, the component a has a characteristic of forming a tough printing layer having a high molecular weight because the curing reaction is difficult to stop, but the initiation reaction is also difficult to proceed. There are drawbacks in that the process takes time and the productivity is lowered, and that the curing does not proceed with a short curing time and the toughness of the printed layer is insufficient. On the other hand, although the component b has a fast initiation reaction and a high production rate, the reaction is likely to stop. Therefore, the cured product has a low molecular weight and the toughness of the printed layer is insufficient. It is preferable to mix components a and b as a cationically polymerizable active energy ray-curable ink since both the curing speed (productivity) and toughness can be achieved. When component c (especially modified silicone oil) is added in addition to components a and b, the curing rate is further improved dramatically. For this reason, since hardening of a printing layer advances by active energy ray irradiation for a short time, it is possible to increase the process speed and improve productivity. Furthermore, since the termination reaction is suppressed, high molecular weight can be achieved and high toughness can be achieved. That is, it is possible to achieve both productivity and toughness at a higher level. Further, by using a mixture of components a, b, and c, the adhesion (applicability for overcoating) between the cationic polymerizable active energy ray-curable ink and other ink (solvent type ink) is dramatically improved.

  In general, when silicone oil is added to the ink, the curing is inhibited and the curing rate is lowered, the releasability is increased, and the adhesion tends to be lowered. However, in the three-component system of the components a to c, the curing speed and the adhesion are improved against these tendencies. The details of the above-described improvement in curing speed, adhesion to plastic film, and the ability to recoat inks are unclear, but are thought to be due to the interaction of the three components of components a to c. For example, component c It is considered that the reactivity increases due to the effect of enclosing the components a and b when the resin is cured by irradiation with active energy rays.

  It is preferable to add a photopolymerization initiator to the cationic polymerizable active energy ray-curable ink of the present invention in order to exhibit active energy ray curability. The photopolymerization initiator of the present invention is a photocationic polymerization initiator, and examples thereof include diazonium salts, diaryliodonium salts, triarylsulfonium salts, silanol / aluminum complexes, sulfonate esters, and imide sulfonates. Of these, diaryl iodonium salts and triarylsulfonium salts are particularly preferable from the viewpoint of reactivity. The content of the photopolymerization initiator is not particularly limited, but is preferably 0.5 to 7% by weight, more preferably 1 to 5% by weight, based on the total weight of the cationic polymerizable active energy ray-curable ink. .

  Moreover, it is preferable to add a sensitizer to the cation polymerizable active energy ray curable ink of the present invention as necessary from the viewpoint of increasing production efficiency. This is particularly effective when the titanium oxide pigment is used. In this case, the sensitizer can be selected from existing sensitizers in consideration of the type of active energy ray used. For example, (1) amine sensitizers such as amines containing nitrogen in the ring, such as aliphatic, aromatic amines, piperidine, (2) urea sensitizers such as allyl, o-tolylthiourea, (3) sodium Sulfur compound sensitizers such as diethyldithiophosphate, (4) anthracene sensitizers, (5) nitrile sensitizers such as N, N-disubstituted-p-aminobenzonitrile compounds, (6) tri -Phosphorus compound sensitizers such as n-butylphosphine, (7) Nitrogen compound sensitizers such as N-nitrosohydroxylamine derivatives and oxazolidine compounds, (8) Chlorine compound sensitizers such as carbon tetrachloride, etc. Sensitizers. Also in the above, in particular, anthracene sensitizers are preferred because of their strong sensitizing action. Of these, thioxanthone and 9,10-dibutoxyanthracene are preferably used. The content of the sensitizer is not particularly limited, but is preferably 0.1 to 5% by weight, particularly preferably 0.3 to 3% by weight, based on the total weight of the ink.

  Moreover, the cation polymerizable active energy ray-curable ink of the present invention may contain a lubricant as necessary. Examples of the lubricant herein include various waxes such as polyolefin wax such as polyethylene wax, fatty acid amide, fatty acid ester, paraffin wax, polytetrafluoroethylene (PTFE) wax and carnauba wax.

  In the cationically polymerizable active energy ray-curable ink of the present invention, the content of the solvent that does not participate in the reaction and is mainly used as a dispersant is preferably 5% by weight or less, more preferably 1% by weight. Most preferably, it is substantially free of solvent. The solvent here refers to, for example, an organic solvent such as toluene, xylene, methyl ethyl ketone, ethyl acetate, methyl alcohol, and ethyl alcohol, and water. In gravure and flexographic printing inks, coating processability and These are usually used for the purpose of improving the compatibility and dispersibility of each component, and do not include reactive diluents incorporated into the cured composition. The cationically polymerizable active energy ray-curable ink of the present invention can exhibit excellent coating properties and dispersibility between components even without a solvent, so that the amount of the organic solvent can be extremely reduced, so that removal of the solvent becomes unnecessary. It is possible to reduce the environmental load.

  The cationically polymerizable active energy ray-curable ink of the present invention is produced by mixing a resin component (for example, the above-mentioned component a, component b, and further component c as necessary), a photopolymerization initiator, and the like. Furthermore, when using other additives, such as a pigment and a sensitizer, it mixes simultaneously. For mixing, a mixer such as a butterfly mixer, a planetary mixer, a pony mixer, a dissolver, a tank mixer, a homomixer, and a homodisper, a mill such as a roll mill, a sand mill, a ball mill, a bead mill, and a line mill, a kneader, and the like are used. The mixing time (retention time) during mixing is preferably 10 to 120 minutes. The obtained ink composition may be used after filtration, if necessary.

  The viscosity (23 ± 2 ° C., 50 rotations, E-type viscometer, JIS Z 8803) of the cationically polymerizable active energy ray-curable ink of the present invention is not particularly limited. For example, when applied by gravure printing Is preferably 10 to 2000 mPa · s, more preferably 20 to 1000 mPa · s. When the viscosity exceeds 2000 mPa · s, the gravure printability may be lowered, and “decrease” or the like may occur, and the decorating property may be lowered. On the other hand, when the viscosity is less than 10 mPa · s, the storage stability may be deteriorated, for example, the pigment or the additive may easily settle. The viscosity can be controlled by an ink component, a blending ratio, a thickener, a thinning agent, and the like.

  The thixotropy of the cationically polymerizable active energy ray-curable ink of the present invention is preferably low, and the thixotropic index (TI value) is preferably less than 20, more preferably less than 15, and still more preferably less than 10. When the TI value is 20 or more, the gravure and flexographic printability may decrease, and the productivity may decrease.

  In the present invention, the surface resistance of the plastic label is provided by providing the printing layer B formed from the cationic polymerizable active energy ray-curable ink on the printing layer A having poor surface resistance such as solvent resistance and scratch resistance. Can be improved. In addition, by using solvent-free cationic polymerizable active energy ray-curable ink for a part of the printing layer, the amount of organic solvent used in the production of plastic labels is reduced, making the manufacturing process excellent in environmental performance. Can do.

[Plastic label]
The plastic label of the present invention has a layer structure in which the printed layer A is formed on at least one surface side of the plastic film, and the printed layer B is formed without any other layers. Although it does not specifically limit as a specific aspect of the plastic label of this invention, For example, (1) Printing layer A which is a transparent plastic film / color printing layer / printing layer B which is a white printing layer; (2) White plastic Print layer A which is a film / color print layer / print layer B which is a clear print layer or a mat layer; (3) Print layer A which is a transparent plastic film / color print layer / print layer A which is a white print layer / white or Print layer B which is a clear print layer; (4) Print layer B which is a clear print layer / Print layer A which is a color print layer / Transparent or white plastic film / Print layer A which is a color or white print layer / White or clear Print layer B which is a print layer; (5) Print layer A which is a transparent plastic film / color print layer / print layer B which is a clear print layer. Among the above, in the case of the layer configuration of (1) or (2), the printed layer B is the outermost surface of the label (the outermost surface on the side in contact with the container when the label is attached to the container or the outermost surface on the opposite side of the container) ) Is effective.

  The plastic film, the printing layer A, and the printing layer B may each have a multilayer structure. In the case of multicolor printing, for example, the printing layer A preferably has a multilayer structure. Moreover, the printing layer A and the printing layer B do not necessarily have to be provided on the entire surface of the label, but it is preferable that there is no portion where only the printing layer A is provided on the plastic film. The printing layer B is preferably provided on the printing layer A.

  In addition to the above, the plastic label of the present invention may be provided with other layers such as an adhesive layer, an ultraviolet protection layer, an anchor coat layer, a primer coat layer, a nonwoven fabric, and paper as necessary.

  The thickness of the printing layer A in the plastic label of the present invention (thickness after solvent removal, total thickness in the case of a multilayer structure) varies depending on the application and the number of colors in the case of multicolor printing, and is not particularly limited. 1-15 micrometers is preferable, Most preferably, it is 0.5-10 micrometers. If the thickness of the printed layer is less than 0.1 μm, it may be difficult to provide the printed layer uniformly, and partial “fading” may occur, resulting in a loss of decorativeness or design. Street printing may be difficult. In addition, when the thickness of the printing layer exceeds 15 μm, a large amount of solvent-based ink is consumed, which increases the amount of organic solvent used, which is not preferable from an environmental point of view. It becomes brittle and easy to peel off.

  The thickness of the printing layer B (total thickness in the case of a multilayer structure) in the plastic label of the present invention varies depending on the application and is not particularly limited, but is preferably 0.1 to 15 μm, particularly preferably 0.5 to 10 μm. It is. When the thickness of the printing layer is less than 0.1 μm, it may be difficult to provide the printing layer uniformly, and partial “bluring” may occur and the decorativeness may be impaired or the surface resistance may be reduced. There is a case. On the other hand, when the thickness of the printing layer exceeds 15 μm, a large amount of cationically polymerizable active energy ray-curable ink is consumed, which is not preferable in terms of cost, and it becomes difficult to apply uniformly, and the printing layer is fragile. It becomes easier to peel off. Among these, when the printing layer B of the present invention is a white printing layer, the thickness is preferably 3 to 10 μm from the viewpoint of concealment, and when the printing layer B is a clear printing layer, from the viewpoint of transparency, the thickness is preferably 0. 2 to 3 μm is preferable. In addition, the thickness of the printing layer B of the present invention hardly changes before and after curing.

  The plastic label of the present invention is generally excellent in decorativeness because the color printing layer is formed with a solvent-type color ink. Moreover, since the printing layer A formed with the solvent-based ink is not exposed, and the surface on the side where the printing layer is provided is covered with the printing layer B with the cationic polymerizable active energy ray-curable ink, Excellent surface resistance such as solvent resistance, chemical resistance, oil resistance, water resistance, acid resistance, alkali resistance, and scratch resistance. For this reason, it can be used widely for applications requiring solvent resistance, water resistance and the like. In addition, the printed layer is hardly damaged during the manufacturing process and the distribution stage. In addition, since the toughness of the printed layer is improved, it is excellent in resistance to squeeze, and the shrink film is also excellent in followability to shrinkage deformation during shrinkage processing.

  Specifically, the plastic label of the present invention can be used for stretch labels, shrink labels, stretch shrink labels, in-mold labels, tack labels, roll labels (wrap-type glued labels), heat-sensitive adhesive labels, and the like. Among these, when used for shrink label applications, the effect of preventing shrinkage whitening, shrinkage peeling, and shrinkage cracks (ink cracks) is obtained, reflecting the good adhesion and followability to shrink processing.

  The plastic label of the present invention is generally mounted on a container and used as a labeled container. Such containers include, for example, soft drink bottles such as PET bottles, milk containers for home delivery, food containers such as seasonings, alcohol beverage bottles, pharmaceutical containers, containers for chemical products such as detergents and sprays, cups, etc. This includes noodle containers. Also, the material of the container includes plastic such as PET, glass, metal and the like. In addition, the plastic label of this invention may be used for adherends other than a container.

[Plastic label manufacturing method]
The method for producing a plastic label of the present invention comprises (1) a step of applying the solvent-based ink to at least one surface of the plastic film and drying to form a printed layer A; (2) on the surface of the printed layer A; It consists of a process of forming a printing layer B by applying a cationic polymerizable active energy ray-curable ink and curing the active energy ray. The steps (1) and (2) may be applied, dried, cured, etc. during the plastic film manufacturing process (in-line coating), or may be performed after film formation (off-line coating). However, off-line coating is preferred from the viewpoint of productivity and workability. Moreover, although the process of (1) and (2) may be performed continuously and may each be performed independently, it is preferable to perform by a continuous process from a viewpoint of productivity.

(Formation of printing layer A)
Gravure printing and flexographic printing are preferable as a method for applying solvent-based ink on a plastic film from the viewpoints of cost, productivity, printing decoration, and the like. Among these, a gravure printing method is particularly preferable. Next, the applied ink layer is dried (heated and dried if necessary) to remove the solvent, and the printed layer A is formed. Although the natural drying may be sufficient as the said drying process, the general heating apparatus (Oven, such as a hot air heater and an infrared oven, an infrared heater, etc.) which can be heated in-line can be used. Among these, a hot air heater is particularly preferable from the viewpoint of safety. The heating temperature at the time of heat drying is preferably 35 to 65 ° C., and particularly in the case of a shrink film, 40 to 60 ° C. is preferable from the viewpoint of drying efficiency and film deformation suppression. In addition, when forming the multilayer printing layer A, such as in the case of multicolor printing, the above-described application / drying process may be repeated.

(Formation of printing layer B)
As a method for applying the cationic polymerizable active energy ray curable ink on the printing layer A, gravure printing, flexographic printing or ink jet printing method is preferable, and gravure printing method is particularly preferable. Next, the applied ink layer is irradiated with active energy rays to cure the ink layer. Curing is preferably performed in a coating step and a series of steps from the viewpoint of productivity. Curing is preferably performed using an ultraviolet (UV) lamp, an ultraviolet LED, an ultraviolet laser, or the like. The active energy ray to be irradiated varies depending on the composition of the cation-polymerizable active energy ray-curable ink and is not particularly limited. However, from the viewpoint of curability, an ultraviolet ray having a wavelength of 200 to 460 nm (near ultraviolet ray) is preferable. The strength is preferably 150 mJ / cm ^{2 to} 1000 mJ / cm ² and the irradiation time is preferably 0.1 to 3 seconds. As needed, you may provide a heating process before and after an active energy ray irradiation process.

  The long plastic label obtained as described above is slit into a predetermined width and wound into a roll to form a plurality of rolls.

  Hereinafter, an example of processing of a plastic label and attachment to a container when the plastic label of the present invention is a shrink label will be described, but the present invention is not limited to this.

[Processing of plastic labels]
While feeding one of the rolls, the long plastic label is formed into a cylindrical shape so that the width direction is the circumferential direction. Specifically, a long plastic label is formed into a cylindrical shape, and a solvent or adhesive such as tetrahydrofuran (THF) or the like (hereinafter referred to as “THF”) is formed on one side edge of the label in a band shape in the longitudinal direction. Solvent etc.) is applied to the inner surface, rolled up into a cylindrical shape, and the solvent applied portion is overlapped at a position of 5-10 mm from the other side edge and adhered to the outer surface (center seal). To obtain a long cylindrical plastic label. In addition, it is preferable that the printing layer is not provided in the part which applies said solvent etc., and the part to adhere | attach.

  In the case where a perforation for label excision is provided, a perforation having a predetermined length and pitch is formed in the longitudinal 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.

[Container with label]
Finally, after cutting the long cylindrical plastic label obtained above, it is attached to a predetermined container, and the label is contracted by heat treatment, and a container with a label is prepared by closely contacting the container. The above long cylindrical plastic label is supplied to an automatic label mounting device (shrink labeler), cut to the required length, and then externally fitted into a container filled with the contents, and a hot air tunnel or steam tunnel at a predetermined temperature is attached. Passed or heated with radiant heat such as infrared rays to cause heat shrinkage and adhere to the container to obtain a labeled 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).

[Methods for measuring physical properties and methods for evaluating effects]

(1) Curability (initial tackiness)
In Examples and Comparative Examples, immediately after the curing treatment was performed at an ultraviolet irradiation process speed (conveyor speed) of 50 m / min, the surface of the printed layer was touched with a finger, and it was visually observed whether or not the finger was inked. When ink was not applied to the finger, it was judged that curability was good (O), and when ink was applied, curability was poor (x).

(2) Adhesiveness (tape peeling test)
The test was performed according to JIS K 5600, except that no cross cuts were made on the grid. The Nichiban tape (width 18mm) was applied to the surface of the plastic label obtained in Examples and Comparative Examples on the surface where the printed layer was provided, peeled in the direction of 90 degrees, and the printed layer remained in an area of 5mm x 5mm. The observed area was observed, and adhesiveness (adhesion) was judged according to the following criteria.
90% or more: Good adhesion (○)
80% or more and less than 90%: Adhesiveness is slightly poor but usable level (△)
Less than 80%: Adhesive failure (×)

(3) Scratch resistance Sample pieces having a length of 100 mm and a width of 100 mm were collected from the plastic labels obtained in Examples and Comparative Examples. Hold both ends of the sample piece with both hands and hold it 10 times. The remaining area of the printed layer on the surface of the printed layer is visually observed. If the remaining area is 90% or more, the resistance to cracking is good (◯), and if the remaining area is less than 90%, the resistance to cracking is poor (x). did.

(4) Scratch resistance A sample piece having a length of 100 mm and a width of 100 mm was collected from the plastic labels obtained in Examples and Comparative Examples. Place the sample on a smooth table, observe the surface after rubbing the surface on the side where the printed layer is provided 10 times in the back of the nail of the hand (20 mm in the longitudinal direction). It was judged.
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 (×)

(5) Viscosity and thixotropy Using an E-type viscometer (“RE115L” manufactured by Toki Sangyo Co., Ltd.), the measurement was performed at 23 ± 2 ° C. according to JIS Z 8803. Moreover, the value which remove | divided the viscosity in rotation speed 1rpm by the viscosity in rotation speed 100rpm was made into the thixo index (TI value).

(6) Film layer thickness, printing layer thickness The film thickness was measured using a stylus type thickness gauge. The printed layer thickness was measured by using a three-dimensional microscope (VK8510 manufactured by Keyence Corporation) for the level difference between the portion provided with the printed layer (coated surface) and the portion not provided with the printed layer (non-coated surface).

(7) Plastic film heat shrinkage (90 ° C)
A rectangular sample piece having a length of 200 mm (mark interval 150 mm) and a width of 10 mm is prepared from the plastic film in the measurement direction (longitudinal direction or width direction).
The sample piece is heat-treated in warm water at 90 ° C. for 10 seconds (under no load), the difference between the marked lines before and after the heat treatment is read, and the thermal contraction rate is calculated by the following formula.
Thermal shrinkage (%) = (L ₀ −L ₁ ) / L ₀ × 100
L ₀ : Mark interval before heat treatment L ₁ : Mark interval after heat treatment

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

Example 1
(Cationically polymerizable active energy ray-curable ink)
As component a, bis [(3-ethyloxetane-3-yl) methyl] ether (manufactured by Toagosei Co., Ltd., trade name “Aron Oxetane OXT-221”) and as component b, an epoxy monomer (manufactured by Daicel Chemical Industries, Ltd.) , Trade name “Celoxide 2021P”), polyether-modified silicone (manufactured by Shin-Etsu Chemical Co., Ltd., trade name “X-22-2516”) as component c, photopolymerization initiator (manufactured by Dow Chemical Co., Ltd., trade name) Table 1 shows "UVI-6992"), titanium dioxide as a white pigment (manufactured by Teika Co., Ltd., trade name "JR-809"), and dibutoxyanthracene (manufactured by Kawasaki Kasei Kogyo Co., Ltd.) as a sensitizer. In accordance with the blended amount (parts by weight), a cationically polymerizable active energy ray-curable ink (white ink) was obtained. No solvent was used.

(Solvent ink)
Acrylic resin (trade name “ARUFON UH2060” manufactured by Toagosei Co., Ltd.) (acrylic resin A), nitrocellulose (trade name “LIG 1/8” manufactured by Bergerac), organic solvent (ethyl acetate / A mixed solvent of propyl acetate), a red pigment (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name “Chromophthal RED 2030SA”) was blended according to the blending amount (part by weight) shown in Table 1, and solvent-based ink (color Ink) was obtained.

(Plastic label)
Using a table-top gravure printing machine (trade name “GRAVO PROOF MINI” manufactured by Nissho Gravure Co., Ltd.) and a gravure plate with 90 lines and a plate depth of 30 μm, the obtained solvent-based ink was transferred to a polyester-based shrink film (Toyobo ( Co., Ltd., trade name “Space Clean S7042”: film thickness 45 μm), full-surface gravure printing at a process speed of 50 m / min, drying by natural drying, solvent removal, printing layer A (thickness: 2 μm, single Layer).
Next, using the same gravure printing machine and gravure plate as described above, the cation polymerizable active energy ray curable ink was gravure printed on the entire surface of the printing layer A at a process speed of 50 m / min (thickness: 4 μm).
Then, the said film was used on the conditions of the conveyor speed of 50 m / min and 240 W / cm using the ultraviolet irradiation device (Fusion UV Systems Japan Co., Ltd. make, brand name "LIGHT HAMMER 10": Output 100%, D valve). Light irradiation was performed to form a printing layer B (thickness: 4 μm, single layer), and the curability was evaluated. The irradiation intensity (measured by the trade name “UV Power Pack” manufactured by EIT Co., Ltd.) is 55 mJ / cm ² (UVC), 515 mJ / cm ² (UVB), 1550 mJ when the conveyor speed is 10 m / min. / Cm ² (UVA) and 955 mJ / cm ² (UVV).
The obtained plastic label was evaluated for adhesion, resistance to scratching and scratch resistance.
As shown in Table 1, the obtained plastic label had good curability of the printed layer B and excellent productivity, and also had good adhesion, resistance to scratching, and scratch resistance.

Examples 2 and 3
As shown in Table 1, a plastic label was obtained in the same manner as in Example 1 by changing the composition of the solvent-type ink.
As shown in Table 1, the obtained plastic label had good curability of the printed layer B and excellent productivity, and also had good adhesion, resistance to scratching, and scratch resistance.

Examples 4-6
A plastic label was obtained in the same manner as in Examples 1 to 3, except that the cationic polymerizable active energy ray-curable ink was changed to a clear ink to which no pigment was added.
As shown in Table 1, the obtained plastic label had good curability of the printed layer B and excellent productivity, and also had good adhesion, resistance to scratching, and scratch resistance.

Comparative Examples 1 and 2
As shown in Table 1, as a solvent-type ink for forming the printing layer A, a urethane resin that is a resin containing a nitrogen atom having an unshared electron pair (product name “FS-64” manufactured by Nippon Kayaku Co., Ltd.) A plastic label was produced in the same manner as in Examples 1 and 4 except that the ink containing was used. As shown in Table 1, the plastic label was inferior in curability of the printing layer B.
Furthermore, although adhesiveness, resistance to scratching and scratch resistance were evaluated, these characteristics were also poor.

  Moreover, about the plastic label obtained in the said Examples 1-6, the container with a label was produced using this label. The obtained plastic label (produced at a conveyor speed of 50 m / min) was cylindrical so that the printing surface was the inner surface in Examples 1 to 3 and the printing layer was the outer side in Examples 4 to 6. After adjusting the length in the circumferential direction so as to be 20% heat-shrinked and attached to the body of the PET bottle, both ends were welded to obtain a cylindrical plastic label. Further, the container was attached to a 500 ml PET bottle, and the label was shrunk by a steam tunnel having an atmospheric temperature of 90 ° C. to obtain a labeled container. The resulting labeled container had an excellent finish.

In addition, each compound shown in Table 1 is as follows. The unit of the blending amount in the table is “parts by weight”.
(Cationically polymerizable active energy ray-curable ink)
Ingredient a: Toagosei Co., Ltd., trade name “Aron Oxetane OXT-221”
Ingredient b: Daicel Chemical Industries, Ltd., trade name “Celoxide 2021P”
Component c: Product name “X-22-2516” manufactured by Shin-Etsu Chemical Co., Ltd.
White pigment: Product name "JR-809" manufactured by Teika Co., Ltd.
Photopolymerization initiator: trade name “UVI-6992” manufactured by Dow Chemical Co., Ltd.
Sensitizer: Dibutoxyanthracene (solvent ink), manufactured by Kawasaki Kasei Kogyo Co., Ltd.
Acrylic resin A: manufactured by Toagosei Co., Ltd., trade name “ARUFON UH2060”
Acrylic resin B: Mitsubishi Rayon Co., Ltd., trade name “Dianar LR1941”
Nitrocellulose: manufactured by Bergerac, trade name “LIG 1/8”
Urethane resin: Nippon Kakko Paint Co., Ltd., trade name “FS-64”
Red pigment: Ciba Specialty Chemicals Co., Ltd., trade name “Chromoval RED 2030SA”

Claims (8)

  On at least one surface of the plastic film, a printing layer A is formed by a solvent-based ink using a resin not containing a nitrogen atom having an unshared electron pair as a binder resin, and the surface of the printing layer A has a cationic polymerizable activity. A plastic label, wherein the printing layer B made of energy ray curable ink is formed without any other layers.   2. The plastic label according to claim 1, wherein the resin not containing a nitrogen atom having an unshared electron pair is at least one resin selected from an acrylic resin, a cellulose resin, a polyester resin, and a vinyl chloride resin.   The plastic label according to claim 1 or 2, wherein the cationic polymerizable active energy ray curable ink contains an oxetane compound and an epoxy compound.   The plastic label according to claim 3, wherein the cationic polymerizable active energy ray-curable ink further contains a silicone compound.   The weight ratio of the oxetane compound and the epoxy compound in the cationic polymerizable active energy ray-curable ink is 2: 8 to 8: 2, and the silicone compound is further added to 100 parts by weight of the total amount of the oxetane compound and the epoxy compound. The plastic label according to claim 4, containing 0.1 to 30 parts by weight.   The plastic label according to any one of claims 1 to 5, wherein the cationic polymerizable active energy ray-curable ink contains 0.1 to 70% by weight of a pigment with respect to the total weight of the ink.   The plastic label according to any one of claims 1 to 6, wherein the plastic label is a shrink label.   After at least one surface of the plastic film is coated with a solvent-type ink containing a resin not containing a nitrogen atom having an unshared electron pair, an organic solvent, and a pigment, and dried to form a printing layer A, the printing layer A A cation polymerizable active energy ray curable resin and a cation polymerizable active energy ray curable ink containing a photopolymerization initiator are applied to the surface of the substrate, and the printed layer B is formed by curing the active energy ray. Item 8. A method for producing a plastic label according to Item 1-7.