JP2008170822A - Plastic label and manufacturing method for the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a plastic label superior in productivity, and excellent in contact property (adhesiveness) between a plastic film and a printing layer and between printing layers, scratch resistance and rubbing resistance of label surface. <P>SOLUTION: The plastic label is constituted wherein on at least one side of the plastic film, a printed layer A printed with a solvent ink in which the added amount of a photoinitiator is 0.1-50 parts by weight, with respect to 100 parts by weight of the solid content weight of the ink (solid content weight, before the photoinitiator is added) 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 having to interpose another layer between them. <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 reduces the amount of the organic solvent used and that satisfies 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-type ink containing a specific amount of a photopolymerization initiator, and further formed thereon a cationic polymerizable active energy ray curing. By providing a printing layer with mold ink, while maintaining the curability of the cationic polymerizable active energy ray curable ink, the plastic label is excellent in all aspects of environmental properties (low solvent usage), cost, and various resistances. As a result, the present invention was completed.

  That is, according to the present invention, the addition amount of the photopolymerization initiator on at least one surface of the plastic film is 0.1 to 100 parts by weight of the solid content weight of the ink (solid content weight before addition of the photopolymerization initiator). A printing layer A is formed with 50 parts by weight of solvent-based ink, and a printing layer B is formed on the surface of the printing layer A without any other layers by using a cationic polymerizable active energy ray-curable ink. A plastic label is provided.

  Furthermore, in the present invention, the addition amount of the photopolymerization initiator is at least 0.1 weight with respect to 100 parts by weight of the solid content weight of the ink (solid content weight before addition of the photopolymerization initiator) on at least one surface of the plastic film. The printing layer C is formed with a solvent-type ink that is less than the portion, the printing layer A is formed on the surface of the printing layer C, and the printing layer B does not pass through other layers on the surface of the printing layer A. A plastic label as described above is provided.

  Furthermore, the present invention provides the plastic label, wherein the photopolymerization initiator is a sulfonium photopolymerization initiator or an iodonium photopolymerization initiator.

  Furthermore, the present invention provides the plastic label, wherein the solvent-type ink contains at least one binder resin selected from urethane resin, acrylic resin, cellulose resin, polyester resin, and vinyl chloride resin.

  Furthermore, the present invention provides the plastic label, wherein the binder resin is a mixed resin of an acrylic resin and a cellulose resin or a mixed resin of a urethane resin and a cellulose resin.

  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 plastic label, wherein the cationically polymerizable active energy ray-curable ink further 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 the 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.

  Further, in the present invention, after at least one surface of the plastic film is coated with a solvent-type ink containing a binder resin, a photopolymerization initiator, an organic solvent, and a pigment and dried to form the printed layer A, the printed layer The surface of A is coated with a cationically polymerizable active energy ray-curable resin and a cationically polymerizable active energy ray-curable ink containing a polymerization initiator, and the printed layer B is formed by curing with active energy rays. A method for manufacturing a plastic label is provided.

  Furthermore, the present invention applies a solvent type ink containing a binder resin, an organic solvent, and a pigment to at least one surface of a plastic film, and dries to form a printed layer C. Further, a binder is formed on the surface of the printed layer C. Resin, photopolymerization initiator, solvent-type ink containing organic solvent is applied and dried to form printed layer A, and then on the surface of printed layer A, a cationic polymerizable active energy ray-curable resin, photopolymerization is started. Provided is a method for producing a plastic label, wherein a printing layer B is formed by applying a cationic polymerizable active energy ray-curable ink containing an agent and curing the active energy ray.

  Furthermore, in the present invention, a solvent type ink containing a binder resin, a photopolymerization initiator, an organic solvent, and a pigment is applied to at least one surface of a plastic film and dried to form a printed layer A, and then an active energy ray is applied. After irradiating the printing layer A, the surface of the printing layer A is coated with a cationic polymerizable active energy ray curable ink containing a cationic polymerizable active energy ray curable resin and a photopolymerization initiator, and active energy ray cured. Thus, a method for producing the plastic label for forming the printing layer B is provided.

  Furthermore, the present invention applies a solvent type ink containing a binder resin, an organic solvent, and a pigment to at least one surface of a plastic film, and dries to form a printed layer C. Further, a binder is formed on the surface of the printed layer C. A solvent-type ink containing a resin, a photopolymerization initiator, and an organic solvent is applied and dried to form a printed layer A. Then, the printed layer A is irradiated with active energy rays, and then the surface of the printed layer A is exposed to a cation. Provided is a method for producing the above-mentioned plastic label, in which a polymerizable active energy ray-curable resin and a cationic polymerizable active energy ray-curable ink containing a photopolymerization initiator are applied and active energy ray-cured to form a printing layer B.

  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 including a specific amount of photopolymerization initiator in the solvent-type ink, even if these different types of ink are overprinted, curing of the cationic polymerizable active energy ray-curable ink is not hindered, and productivity is improved. Excellent plastic labels can be 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”) with a solvent-type ink containing a photopolymerization initiator is formed on at least one surface side of the plastic film, and the surface of the printing layer A (plastic) On the surface opposite to the film side, a printing layer (referred to as “printing layer B”) made of a cationic 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.

  In the plastic label of the present invention, a printing layer (referred to as “printing layer C”) with a solvent-based ink substantially not containing a photopolymerization initiator is formed on at least one surface side of the plastic film. A laminated structure in which the printing layer A and the printing layer B are formed on the side opposite to the plastic film may be employed. In this case as well, the printing layer C may be formed on the plastic film via another layer, or another layer may be formed between the printing layer C and the printing layer A. .

  The plastic film, the printing layer A, the printing layer B, and the printing layer C may each have a multilayer structure. 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]
In the plastic label of the present invention, the printing layer A is formed on the surface of the plastic film by applying solvent type ink. When the printing layer C is not provided, 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. Moreover, when the printing layer C is provided as a color printing layer, it is preferably used as an anchor coat layer of the printing layer B, and improves the curability of the cationic polymerizable active energy ray curable ink forming the printing layer B. Take a role. The solvent-based ink includes so-called water-based ink using water as a solvent.

  The solvent-type ink for forming the printing layer A of the present invention contains a binder resin, a photopolymerization initiator, and an organic solvent as essential components. Moreover, when the printing layer A is a color printing layer, it is preferable to contain a coloring agent further.

  As the binder resin in the solvent-based ink for forming the printing layer A of the present invention, a known and commonly used binder resin used for solvent-based inks can be used. Examples of such resins include urethane resins, acrylic resins, cellulose resins, polyester resins, and vinyl chloride resins. Among these, urethane resin, acrylic resin, and cellulose resin are preferable from the viewpoint of adhesion to a plastic film (also referred to as adhesiveness), and acrylic resin / cellulose resin or urethane resin / It is a mixed resin of cellulosic resins. Furthermore, in the case of a mixed resin of acrylic resin / cellulose resin, the curability is the best.

  Of the binder resins, the urethane-based resin is not particularly limited as long as it is a resin obtained by reacting a polyisocyanate compound and a polyol compound and exhibits an adhesive force (adhesive force) to a plastic film, Conventional or known polyurethane resins having such characteristics can be used.

  As the polyisocyanate compound, one or a mixture of two or more known diisocyanates of aromatic, aliphatic and alicyclic groups can be used. Specific examples of diisocyanates include tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, 1,3-phenylene diisocyanate, hexamethylene diisocyanate, xylylene diisocyanate, 1,5-naphthalene diisocyanate, and isophorone diisocyanate. If necessary, trifunctional or higher functional polyisocyanates and polyisocyanate adducts can be mixed with the diisocyanate.

  Examples of the polyol compound include ethylene glycol, diethylene glycol, 1,3-propanediol, propylene glycol, butanediol (1,3-butanediol, 1,4-butanediol, etc.), 1,6-hexanediol, and cyclohexanedimethanol. Low molecular weight glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, polytetramethylene glycol-polycaprolactone copolymer and other polyether diols; propylene glycol, butanediol, hexanediol and other diols and adipic acid, Polyester diol obtained from dibasic acids such as sebacic acid, azelaic acid, isophthalic acid, terephthalic acid, fumaric acid; polycaprolactone polyol, polyvale Lactone polyol, a known diols, lactone diols such as lactone block copolymer polyols can be used. Moreover, said diols and a trifunctional or more than trifunctional polyol compound can also be mixed and used as needed.

  The weight average molecular weight of the urethane resin is generally about 5000 to 100,000, preferably about 10,000 to 70000. When the weight average molecular weight is less than 5,000, the dried coating film is poor and has poor toughness, and when it exceeds 100,000, the solubility tends to decrease and the viscosity tends to increase. A polyurethane resin can be used 1 type or in combination of 2 or more types.

  As the urethane-based resin used in the present invention, “Samprene IB911” manufactured by Sanyo Chemical Co., Ltd., “FS-64” manufactured by Nippon Kayaku Paint Co., Ltd., etc. are available on the market.

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; N-methylol (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N-dimethyl (Meth) acrylic acid amide derivatives such as (meth) acrylamide and N, N-diethyl (meth) acrylamide; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate, dipropylaminoethyl (meth) acrylate, dimethylamino (Meth) acrylic acid dialkylaminoalkyl esters such as propyl (meth) acrylate and dipropylaminopropyl (meth) acrylate; styrene compounds such as styrene, vinyltoluene and α-methylstyrene; vinyl acetate, Vinyl esters such as vinyl pionate; Vinyl halides such as vinyl chloride; Vinyl ethers such as methyl vinyl ether; Cyano group-containing vinyl compounds such as (meth) acrylonitrile; Polymerizability of olefins and dienes such as ethylene and propylene Unsaturated compounds 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 7000 to 40000. When the weight average molecular weight is less than 8000, the 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.

  In addition, the cellulose resin is preferable because the adhesion of the printing layer A to the plastic film, the toughness of the coating film, the hardness, and the ink cracking resistance are improved by mixing with the 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 order to improve the curability of the cationically polymerizable active energy ray-curable ink that forms the printing layer B, the solvent-type ink that forms the printing layer A of the present invention has an active energy ray polymerization initiator (“photopolymerization initiator”). Is added). The photopolymerization initiator is a photocationic polymerization initiator, and examples thereof include diazonium salts, diaryliodonium salts, triarylsulfonium salts, silanol / aluminum complexes, sulfonate esters, and imide sulfonates. Among these, from the viewpoint of reactivity, iodonium photopolymerization initiators such as diaryl iodonium salts and sulfonium photopolymerization initiators such as triarylsulfonium salts are particularly preferable. The addition amount of a photoinitiator is 0.1-50 weight part with respect to 100 weight part of solid content weight (solid content weight before photoinitiator addition) of the solvent-type ink which forms the printing layer A. The amount is preferably 0.2 to 40 parts by weight. In addition, the solid content weight of the said solvent-type ink is a solid content weight before adding a photoinitiator, and is solid content weight, such as binder resin and a pigment. Moreover, when the photoinitiator to add is a solution, the said addition amount is calculated using the weight of a solution.

  Moreover, it is preferable to add a sensitizer to the solvent-type ink for forming the printing layer A of the present invention. This is particularly effective when a titanium oxide pigment or the like is added to the ink. In addition, the kind of sensitizer can use the thing similar to the cation polymerizable active energy ray hardening-type ink mentioned later. The addition amount of the sensitizer is preferably 0.1 to 50 parts by weight, more preferably 0.2 to 100 parts by weight of the solids weight of the ink (solids weight before addition of the photopolymerization initiator). ~ 40 parts by weight. Calculation of the addition amount is the same as in the case of the photopolymerization initiator.

  As the organic solvent in the solvent-type ink for forming the printing layer A of the present invention, solvents usually used for printing inks such as gravure printing and flexographic printing can be used, for example, ethyl acetate, propyl acetate, butyl acetate, etc. Acetates of methanol; alcohols such as methanol, 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; Cycloaliphatic hydrocarbons such as cyclohexane and methylcyclohexane; glycols such as ethylene glycol and propylene glycol; glycol ethers such as propylene glycol monomethyl ether and propylene glycol monobutyl ether; propylene Such as glycol ether esters such as glycol monomethyl 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.

  When the solvent type ink for forming the printing layer A of the present invention is a color ink (for example, when the printing layer C is not provided and the printing layer A is a color printing layer), the solvent type ink includes a dye, It is preferable to add a colorant such as a pigment. Of these, organic and inorganic color pigments are preferably used from the viewpoint of colorability. Examples of the pigment include white pigments such as titanium oxide (titanium dioxide), indigo (blue) pigments such as copper phthalocyanine blue, red pigments such as condensed azo pigments, 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 be used 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 for forming the printing layer A of the present invention is produced by mixing the binder resin (urethane resin, acrylic resin, cellulose resin, etc.), organic solvent, photopolymerization initiator, colorant and the like. . When other additives are used, they are mixed at the same time. Mixing can be performed by a known and common 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, or a ball mill. , Bead mill, line mill and other mills, kneaders and the like. 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 that forms the printing layer A of the present invention is not particularly limited, but is preferably 10 to 2000 mPa · s, and more preferably when applied by gravure printing, for example. Is 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 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 forming the printing layer A 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 or the printing layer A and the printing layer C described later as a solvent-type ink, the dispersibility of the pigment is good, the kind of pigment to be added, and the degree of freedom of the content is high. A color printing layer can be formed with a color ink having good coatability. For this reason, color printing excellent in design is possible. In addition, since solvent-based ink is less expensive than cationically polymerizable active energy ray-curable ink, using the solvent-based ink as a part of the printing layer is advantageous in terms of production cost.

  In the present invention, by adding a photopolymerization initiator to the printing layer A, it is possible to suppress a decrease in the curing rate when the cationic polymerizable active energy ray-curable ink is applied and cured on the printing layer A, which is favorable. Exhibits curability. In general, when a cationic polymerizable active energy ray-curable ink is applied and cured on a printing layer made of solvent-based ink, the curing rate due to active energy ray curing tends to decrease. In particular, when the solvent-type ink is formed using a binder resin containing a nitrogen atom having an unshared electron pair such as a polyurethane resin, the curing rate is remarkably reduced. 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. Even when the solvent-type ink layer is made of an acrylic resin that does not contain a nitrogen atom having an unshared electron pair or the like, the curing speed is insufficient for high-speed printing.

  On the other hand, in this invention, since the photoinitiator is added in the printing layer A, the said superposition | polymerization inhibition can be suppressed and also sclerosis | hardenability improves since a hardening reaction arises also from the printing layer A side. . After forming the printing layer A and before applying the printing layer B, it is preferable to irradiate with active energy rays in advance because the above-described effects can be more effectively exhibited.

[Print layer B]
In the plastic label of the present invention, the printing layer B is formed on the surface of the printing layer A by applying and curing a cationic polymerizable active energy ray-curable ink. The printing layer B plays a role of imparting surface resistance such as solvent resistance, scratch resistance, and slip resistance by covering the A layer as well as the base of color printing display, glossing, matting and the like. Layers, 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 composition containing a compound (hereinafter referred to as component b) as an essential 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 used as a colored ink such as a white ink, it is preferable to contain a colorant such as a pigment in addition to the above components. Moreover, it is preferable to contain a photoinitiator (photocation polymerization initiator) in order to develop 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. Of these, 3-ethyl-3- (hydroxymethyl) oxetane and bis [(3-ethyloxetane-3-yl) methyl] are particularly preferable from the viewpoints of coating processability and ink curability. 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 or a mat ink containing a pigment, the content is preferably 30 to 95% by weight, more preferably 35 to 90% by weight.

  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, carboxyl-modified silicone, and fluorine-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, 100 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 cationic 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 matte layer, it is preferable to add 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. Further, the content of titanium oxide is preferably 20 to 60% by weight, more preferably 30 to 55% by weight, based on the total weight of the ink, from the viewpoints of concealability and suppression of coarse protrusion formation.

  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. Although content of a photoinitiator is not specifically limited, 0.5-7 weight% is preferable with respect to the total weight of ink, More preferably, it is 1-5 weight%.

  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, and a kneader 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. Moreover, since the usage-amount of the organic solvent at the time of plastic label manufacture can be reduced by using a solvent-free type cation polymerizable active energy ray hardening-type ink for a part of printing layer, it is preferable also from an environmental viewpoint.

[Print layer C]
In the plastic label of the present invention, the printing layer C may be formed by applying a solvent-type ink substantially free of a photopolymerization initiator between the plastic film and the printing layer A. . When the printing layer C is provided, the printing layer C 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. When the printing layer C is provided in addition to the printing layer A, the amount of the photopolymerization initiator added as the whole printing layer can be reduced, which is advantageous in terms of cost.

  The solvent-type ink for forming the printing layer C of the present invention is the same as the solvent-type ink for forming the printing layer A except that it contains substantially no photopolymerization initiator, that is, a binder resin and an organic solvent are essential. The component of Since the printing layer C is preferably used as a color printing layer, the ink preferably further contains a colorant.

  As the binder resin, the organic solvent, and the colorant in the solvent-type ink for forming the printing layer C of the present invention, those exemplified for the solvent-type ink for forming the above-mentioned printing layer A can be used, and preferable inclusion in the ink The amount and the like are the same as in the case of the solvent-type ink for forming the printing layer A. In addition, since the adhesiveness of the printing layer A and the printing layer C improves especially by using the same kind (preferably the same) binder resin and organic solvent as the solvent type ink which forms the printing layer A, it is preferable.

  The solvent-based ink forming the printing layer C of the present invention contains substantially no photopolymerization initiator from the viewpoint of cost reduction. Here, “substantially not contained” means that the added amount is 0.1 parts by weight with respect to 100 parts by weight of the solid content of the solvent-based ink (solid content before addition of the photopolymerization initiator). The amount is less than the corresponding amount, preferably less than 0.01 part by weight.

[Plastic label]
The plastic label of the present invention has a “laminated structure in which the printing layer A and the printing layer B are laminated without any other layer” on at least one surface side of the plastic film (the printing layer B is on the surface layer side). It is the layer structure which has at least. Among these, the layer configuration of plastic film / printing layer A / printing layer B and the layer configuration of plastic film / printing layer C / printing layer A / printing layer B are preferable. Further specific embodiments are not particularly limited. 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 film / color printing layer A printing layer A / clear printing layer or a printing layer B which is a matte layer;
(3) transparent plastic film / printing layer A as a color printing layer / printing layer A as a white printing layer / printing layer B as a white or clear printing layer; (4) printing layer B / color as a clear printing layer; Printing layer A which is a printing layer / transparent or white plastic film / printing layer A which is a color or white printing layer / printing layer B which is a white or clear printing layer; (5) printing layer which is a transparent plastic film / color printing layer C / printing layer A which is a transparent printing layer (anchor layer) / printing layer B which is a white printing layer; (6) white plastic film / printing layer which is a color printing layer C / printing which is a transparent printing layer (anchor layer) Layer A / printing layer B which is a clear printing layer or mat layer; (7) transparent plastic film / printing layer C which is a color printing layer / printing layer C which is a white printing layer / transparent printing layer (a) And printing layer B is a print layer A / white or clear printed layer is a car layer) can be mentioned.

  In the plastic label of the present invention, the plastic film, the printing layer A, the printing layer B, and the printing layer C may each have a multilayer structure. In the case of multicolor printing, for example, the printing layer A or the printing layer C is A multilayer structure is preferred. Further, the printing layer A, the printing layer B, and the printing layer C are not necessarily provided on the entire surface of the label, but the printing layer A or the portion where the printing layer C is exposed or the layered structure of the printing layer C / printing layer B. In the case where a printing layer is provided, it is desirable that the structure is at least covered with the printing layer B. Furthermore, it is desirable that the printing layer C has a structure covered with the printing layer B via the printing layer A which is an anchor layer.

  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. In addition, when printing layer A is an anchor layer, although it does not specifically limit, 0.1-10 micrometers is preferable from a viewpoint of cost reduction or sclerosis | hardenability improvement, More preferably, it is 0.5-5 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.

  When the printing layer C is provided on the plastic label of the present invention, the thickness of the printing layer C (total thickness in the case of a multilayer structure) is not particularly limited, but is preferably in the same range as the printing layer A. .

  The plastic label of the present invention is excellent in decorativeness because the color printing layer is formed with a solvent-type color ink. Moreover, the printing layer A and the printing layer C formed by the solvent type ink are not exposed, and the surface on the side where the printing layer is provided is covered with the printing layer B by the cationic polymerizable active energy ray curable ink. Therefore, it has 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 example of the manufacturing method of the plastic label of this invention is shown below. When the plastic label of the present invention has a layer structure of plastic film / printing layer A / printing layer B, (1) solvent-type ink for forming the printing layer A is formed on at least one surface of the plastic film. A step of forming a printed layer A by coating and drying; (2) a step of applying a cationic polymerizable active energy ray-curable ink to the surface of the printed layer A, and forming a printed layer B by active energy ray curing. It is included as an essential process. Further, (3) a step of irradiating the print layer A with active energy rays is provided between the steps (1) and (2) (that is, the order of steps (1), (3), and (2)). Is preferable because the curing speed when the printing layer B is cured is improved.

  Further, when the plastic label of the present invention has a layer structure of plastic film / printing layer C / printing layer A / printing layer B, (4) the printing layer C is formed on at least one side of the plastic film. A step of applying a solvent-type ink for drying and forming a printing layer C; (5) applying a solvent-type ink for forming the printing layer A on the surface of the printing layer C and drying the printing layer C; A step of forming A; (6) A step of applying the cationic polymerizable active energy ray-curable ink to the surface of the printing layer A and curing the active energy ray to form the printing layer B is included as an essential step. Further, (7) a step of irradiating the print layer A with active energy rays is provided between the above steps (5) and (6) (that is, (4), (5), (7), (6) Is preferable because the curing speed when the printing layer B is cured is improved.

  The above process may be provided during the plastic film production process (in-line coating) or after film formation (off-line coating), but from the viewpoint of productivity and workability, the offline coating may be performed. preferable. Moreover, although said process may be performed continuously and may each be performed independently, it is preferable to perform by a continuous process from a viewpoint of productivity. Further, when another layer is provided between the plastic film and the printing layer A or the printing layer C, the other layer is formed on the plastic film before the step of forming the printing layer A or the printing layer C. A process may be provided.

(Formation of printing layer A)
As a method for applying solvent-type ink for forming the printing layer A on the plastic film or the printing layer C, gravure printing and flexographic printing are preferable 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 as necessary), the solvent is removed, and the printed layer A is formed. The drying may be natural drying, but a general heating device that can be heated in-line (hot air heater, oven such as an infrared oven, infrared heater, etc.) may 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. In addition, when the active energy ray irradiation is performed after the printing layer A is formed, it is preferable to perform the irradiation conditions similar to the conditions in the following printing layer B.

(Formation of printing layer B)
As a method of 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 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.

(Formation of printing layer C)
As a method for forming the printing layer C on the plastic film, the same method as the printing layer A described above can be used. The print layer C does not need to be irradiated with active energy rays.

  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) of cationically polymerizable active energy ray-curable ink
In Examples and Comparative Examples, the surface of the print layer was touched with a finger immediately after the ultraviolet curing treatment (process speed: 70 m / min) of the print layer B, 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) Adhesion between printing layer A / printing layer B (tape peeling test)
The plastic labels obtained in Examples and Comparative Examples were evaluated. The test was performed according to JIS K 5600, except that no cross cuts were made on the grid. Nichiban tape (width 18 mm) was applied to the surface of the plastic label obtained in the examples and comparative examples on the surface provided with the print layer, peeled in the direction of 90 degrees, and the print layer (print The remaining area of layer B) was observed and 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%: poor adhesion (×)

(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 printing layer (printing layer B) on the surface of the printing layer is visually observed, and if the remaining area is 90% or more, the resistance to scumming is good (O), and if it is less than 90%, the suffice resistance is poor (X) was judged.

(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 (printed layer B) is not peeled off 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) Film thickness and printed 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).

(6) 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 1 (manufactured by Dow Chemical Co., Ltd.), product Table 1 shows titanium dioxide (manufactured by Teika Co., Ltd., trade name “JR-809”) as a white pigment, and dibutoxyanthracene (manufactured by Kawasaki Kasei Kogyo Co., Ltd.) as a sensitizer. According to the indicated blending amount (parts by weight), a cationic polymerizable active energy ray curable ink (white ink) was obtained. No solvent was used.

(Solvent ink)
As binder resin, acrylic resin A (manufactured by Toagosei Co., Ltd., trade name “ARUFON UH2060”), nitrocellulose resin 1 (manufactured by Bergerac, trade name “LIG 1/8”), organic solvent (ethyl acetate / propyl acetate) Mixed solvent), red pigment (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name “chromoftal RED 2030SA”), photopolymerization initiator 1 (manufactured by Dow Chemical Co., Ltd., trade name “UVI-6992”), According to the blending amount (parts by weight) shown in Fig. 1, solvent type ink (color ink) was obtained.

(Plastic label)
Tabletop gravure printer (made by Nissho Gravure Co., Ltd., trade name “GRAVO PROOF MINI”) and 90-line gravure plate with a plate depth of 30 μm, and the solvent-based ink obtained was transferred to a polyester-based shrink film (Toyobo Co., Ltd. ), Product 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).
Furthermore, using the ultraviolet irradiation device (Fusion UV Systems Japan Co., Ltd., brand name "LIGHT HAMMER 10": output 100%, D bulb) for the printed layer A, the conveyor speed is 70 m / min, 240 W / cm. Ultraviolet irradiation was performed under conditions.
Next, using the same gravure printing machine and gravure plate as described above, the entire surface of the printing layer A was subjected to gravure printing (thickness: 4 μm) at a process speed of 50 m / min.
Thereafter, an ultraviolet irradiation device (trade name “LIGHT HAMMER 10” manufactured by Fusion UV Systems Japan Co., Ltd .: output 100%, D valve) is used on the film under the conditions of a conveyor speed of 70 m / min and 240 W / cm. Irradiation with ultraviolet rays 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 (adhesiveness), resistance to scratching, and scratch resistance.
As shown in Table 1, the obtained plastic label has good curability of the printing layer B and excellent productivity, and also has good adhesion between the printing layer A and the printing layer B, resistance to scratching, and scratch resistance. there were.

Examples 2-8, Comparative Examples 1-6
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 plastic labels (Examples) satisfying the provisions of the present invention have good curability of the printing layer B and excellent productivity, and adhesion between the printing layer A and the printing layer B, and resistance to rubiness. The scratch resistance was also good. On the other hand, the plastic label (comparative example) that does not satisfy the provisions of the present invention has poor curability of the active energy ray-curable ink (printing layer B). In addition, about the plastic label of the comparative example, since the printing layer was not hardened | cured, the abrasion resistance and the scratch resistance could not be evaluated.

Example 9
(Cationically polymerizable active energy ray-curable ink)
The same cationically polymerizable active energy ray-curable ink as in Example 1 was used.

(Solvent ink for forming the printing layer A (anchor coating agent))
Acrylic resin C (made by Toagosei Co., Ltd., trade name “ARUFON UH2900”), acrylic resin D (made by Toagosei Co., Ltd., trade name “ARUFON UH3000”) and nitrocellulose resin 2 (made by Asahi Kasei, product) No. “HIG 1”), organic solvent (mixed solvent of ethyl acetate / propyl acetate), photopolymerization initiator 1 (manufactured by Dow Chemical Co., Ltd., trade name “UVI-6992”) are shown in Table 2. The solvent-based ink (anchor coating agent) which mixes according to (weight part) and forms the printing layer A was obtained.

(Solvent ink (color ink) that forms the printing layer C)
As binder resin, acrylic resin A (manufactured by Toagosei Co., Ltd., trade name “ARUFON UH2060”), nitrocellulose resin 1 (manufactured by Bergerac, trade name “LIG 1/8”), organic solvent (ethyl acetate / propyl acetate) Mixed solvent), red pigment (manufactured by Ciba Specialty Chemicals Co., Ltd., trade name “chromoftal RED 2030SA”) according to the blending amount (parts by weight) shown in Table 2, and containing no photopolymerization initiator, A solvent-type ink (color ink) for forming the printing layer C was obtained.

(Plastic label)
Table-top gravure printing machine (made by Nissho Gravure Co., Ltd., trade name “GRAVO PROOF MINI”) and 90-line gravure plate with plate depth of 30 μm, solvent-based ink (color ink) that forms the printed layer C obtained On one side of a polyester shrink film (trade name “Space Clean S7042”: film thickness 45 μm, manufactured by Toyobo Co., Ltd.), subjected to full gravure printing at a process speed of 50 m / min, dried by natural drying, and the solvent removed. A printing layer C (thickness: 2 μm, single layer) was formed.
Next, using the same gravure printing machine and gravure plate as above, solvent-type ink (anchor coating agent) for forming the printing layer A is subjected to gravure printing on the printing layer C at a process speed of 50 m / min, Drying was performed by natural drying, the solvent was removed, and a printing layer C (thickness: 2 μm, single layer) was formed. The printed layer A was irradiated with ultraviolet rays under the same conditions as in Example 1.
Further, in the same manner as in Example 1, the active energy ray-curable ink was printed on the printing layer A and irradiated with ultraviolet rays to form the printing layer B (thickness: 4 μm, single layer), and the curability was evaluated. .
The obtained plastic label was evaluated for adhesion, resistance to scratching and scratch resistance.
As shown in Table 2, the obtained plastic label has good curability of the printing layer B and excellent productivity, and also has good adhesion between the printing layer A and the printing layer B, resistance to scratching, and scratch resistance. there were.

Examples 10-13, Comparative Examples 7-12
As shown in Table 2, a plastic label was obtained in the same manner as in Example 1 except that the composition of the solvent-type ink was changed.

  As shown in Table 2, the plastic label (Example) satisfying the provisions of the present invention has good curability of the printing layer B and excellent productivity, and further, adhesion between the printing layer A and the printing layer B, and resistance to abrasion. The scratch resistance was also good. On the other hand, the plastic label (comparative example) that does not satisfy the provisions of the present invention has poor curability of the active energy ray-curable ink (printing layer B). In addition, about the plastic label of the comparative example, since the printing layer was not hardened | cured, the abrasion resistance and the scratch resistance could not be evaluated.

  Moreover, about the plastic label obtained in the said Example, the labeled container was produced using this label. The obtained plastic label is formed in a cylindrical shape so that the printing surface is the inner surface, and the length in the circumferential direction is adjusted so as to be attached to the body of the PET bottle after being heat-shrinked by 20%. Was 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 and Table 2 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 1: manufactured by Dow Chemical Co., Ltd., trade name “UVI-6992”
Sensitizer: Dibutoxyanthracene (solvent ink), manufactured by Kawasaki Kasei Kogyo Co., Ltd.
Acrylic resin A: manufactured by Toagosei Co., Ltd., trade name “ARUFON UH2060” (solid content 50% by weight)
Acrylic resin B: manufactured by Mitsubishi Rayon Co., Ltd., trade name “Dianar LR1941” (solid content 50% by weight)
Acrylic resin C: manufactured by Toagosei Co., Ltd., trade name “ARUFON UH2900” (solid content: 100% by weight)
Acrylic resin D: manufactured by Toagosei Co., Ltd., trade name “ARUFON UH3000” (solid content: 100% by weight)
Urethane resin: Nippon Kakko Paint Co., Ltd., trade name “FS-64” (solid content 40% by weight)
Nitrocellulose resin 1: manufactured by Bergerac, trade name “LIG 1/8” (solid content: 100% by weight)
Nitrocellulose resin 2: manufactured by Asahi Kasei Co., Ltd., trade name “HIG 1” (solid content: 100% by weight)
CAB resin: manufactured by Eastman Chemical Japan Co., Ltd., trade name “CAB381-2” (weight average molecular weight: 40000) (solid content: 100% by weight)
Red pigment: Ciba Specialty Chemicals Co., Ltd., trade name “Chromoval RED 2030SA” (solid content: 100% by weight)
Photopolymerization initiator 1: manufactured by Dow Chemical Co., Ltd., trade name “UVI-6992”
Photopolymerization initiator 2: Ciba Specialty Chemicals Co., Ltd., trade name “IRGACURE 250”

Claims (14)

  The solvent in which the addition amount of the photopolymerization initiator is 0.1 to 50 parts by weight with respect to 100 parts by weight of the solid content of the ink (solid content before addition of the photopolymerization initiator) on at least one surface of the plastic film A printing layer A is formed by a mold ink, and a printing layer B is formed on the surface of the printing layer A by a cationic polymerizable active energy ray-curable ink without any other layers. label.   The solvent type in which the addition amount of the photopolymerization initiator is less than 0.1 parts by weight with respect to 100 parts by weight of the solid content of the ink (solid content before addition of the photopolymerization initiator) on at least one surface of the plastic film A printing layer C made of ink is formed, the printing layer A is formed on the surface of the printing layer C, and the printing layer B is formed on the surface of the printing layer A without any other layers. Item 2. A plastic label according to Item 1.   The plastic label according to claim 1 or 2, wherein the photopolymerization initiator is a sulfonium photopolymerization initiator or an iodonium photopolymerization initiator.   The plastic label according to any one of claims 1 to 3, wherein the solvent-type ink contains at least one binder resin selected from urethane resins, acrylic resins, cellulose resins, polyester resins, and vinyl chloride resins. .   The plastic label according to claim 4, wherein the binder resin is a mixed resin of an acrylic resin and a cellulose resin or a mixed resin of a urethane resin and a cellulose resin.   The plastic label according to any one of claims 1 to 5, wherein the cationic polymerizable active energy ray-curable ink contains an oxetane compound and an epoxy compound.   The plastic label according to claim 6, 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 7, containing 0.1 to 30 parts by weight.   The plastic label according to any one of claims 1 to 8, wherein the cationic polymerizable active energy ray-curable ink contains a pigment in an amount of 0.1 to 70% by weight based on the total weight of the ink.   The plastic label according to any one of claims 1 to 9, wherein the plastic label is a shrink label.   A solvent-type ink containing a binder resin, a photopolymerization initiator, an organic solvent, and a pigment is applied to at least one surface of the plastic film and dried to form a printing layer A, and then a cation is applied to the surface of the printing layer A. The printing layer B is formed by applying a polymerizable active energy ray-curable resin and a cationic polymerizable active energy ray-curable ink containing a photopolymerization initiator and curing the active energy ray. The manufacturing method of the plastic label of description.   A solvent-type ink containing a binder resin, an organic solvent, and a pigment is applied to at least one surface of the plastic film and dried to form a printed layer C. Further, a binder resin and a photopolymerization initiator are formed on the surface of the printed layer C. Then, after applying a solvent-type ink containing an organic solvent and drying to form the printing layer A, the surface of the printing layer A is further cationically polymerizable active energy ray-curable resin and a cationic polymerization agent containing a photopolymerization initiator. The method for producing a plastic label according to claim 2, wherein the printing layer B is formed by applying an active energy ray-curable ink and curing the active energy ray.   After applying a solvent type ink containing a binder resin, a photopolymerization initiator, an organic solvent, and a pigment to at least one surface of the plastic film and drying to form the printing layer A, the printing layer A is irradiated with active energy rays. Thereafter, 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. The method for producing a plastic label according to claim 11.   A solvent-type ink containing a binder resin, an organic solvent, and a pigment is applied to at least one surface of the plastic film and dried to form a printed layer C. Further, a binder resin and a photopolymerization initiator are formed on the surface of the printed layer C. After applying solvent-type ink containing an organic solvent and drying to form the printing layer A, the printing layer A is irradiated with active energy rays, and then the surface of the printing layer A is cured with cationic polymerizable active energy rays. The method for producing a plastic label according to claim 12, wherein the printing layer B is formed by applying a cationic polymerizable active energy ray-curable ink containing a mold resin and a photopolymerization initiator and curing the active energy ray.