JP2016155336A - Printing ink laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a printing ink laminate that is excellent in various physical properties of coating films by using a combination of ink film layers based on different resins.SOLUTION: A printing ink laminate excellent in various physical properties of coating films can be obtained by specifying acid values of an acrylic resin and a polyurethane resin and using a suitable combination of ink coating layers formed of the respective resins, without having an over-print varnish layer in a top face printing configuration or without having an anchor coat varnish layer in a back face printing configuration.SELECTED DRAWING: None

Description

  The present invention relates to a printing ink laminate, and more particularly to a printing ink laminate having various coating film properties that are excellent by using a combination of different resin-based ink coating layers.

  Product packaging is often printed with printing inks to protect the surface and increase consumer willingness to purchase. These packages are mainly obtained by printing on a plastic film substrate by a method such as flexographic printing or gravure printing and then processing according to the contents.

  Among plastic packaging, especially sanitary ware packaging and food packaging, the packaging is processed so that the printed surface does not touch the contents. In packaging in which printing ink is printed on a plastic film substrate, the printing ink layer is exposed to the outside, so that the printing ink layer is physically rubbed at each stage of processing, filling, and distribution. On the other hand, in a packaging in which printing ink is printed on the back side of a plastic film substrate, the printed material consisting of the plastic substrate and the printing ink layer is laminated with the sealant film via an adhesive, so the printing ink layer is directly applied to the contents. Although it is not touched, it must be laminated.

  In surface printing, a method of strengthening the coating film strength by providing an overprint varnish layer on the printing ink layer is generally performed against friction. On the other hand, in reverse printing, in order to ensure laminating suitability, a technique for improving the adhesion between the plastic film substrate and the printing ink layer is generally performed by providing an anchor coat varnish layer under the printing ink layer. Yes.

  In recent years, in addition to improving the image quality of plastic packaging, printing ink layers are required to have high-quality coating film properties such as adhesion, friction resistance, water resistance, and blocking resistance. Furthermore, since the demand for environmental burden reduction and safety at the time of printing increases, reduction of the volatile organic compound contained in the printing ink layer and water-based treatment have been demanded.

  For these problems, when a known aqueous acrylic resin system is used as the binder resin, there is a problem that the coating film is hard and the adhesion to various substrates and followability are poor. On the other hand, when using a known aqueous polyurethane resin system as a binder resin, in addition to the problem that the coating film is flexible and the friction resistance and blocking resistance are inferior, the problem is low pigment dispersibility and re-dissolvability It is as.

  For this reason, various attempts have been made in recent years. In particular, as in Patent Document 1, by combining a water-based acrylic resin-based color ink film layer and a water-based polyurethane resin-based white ink film layer, it is possible to obtain film properties and ink properties that could not be obtained so far. Can be done. However, since the combination configuration of these ink film layers requires an overprint varnish layer or an anchor coat varnish layer, there remains a problem regarding productivity during printing.

Japanese Patent Laying-Open No. 2005-225083

  An object of this invention is to provide the printing ink laminated body which has various various coating-film physical properties, without using an overprint varnish layer and an anchor coat varnish layer.

  As a result of intensive studies on the above problems, the present inventor has found that the problem can be solved by using a combination of different resin-based ink film layers described below, and has reached the present invention.

That is, the present invention
A printing ink structure (I) in which a plastic film (X) is laminated with a first ink film layer (Y), a second ink film layer (Z), and a sealant film in order through an adhesive. )
Or the printing ink structure (II) formed by laminating the second ink film layer (Z) and the first ink film layer (Y) in this order on the plastic film (X).
It is a printing ink laminated body which has these, Comprising: It is the following (1)-(3), It is related with the printing ink laminated body characterized by the above-mentioned.
(1) The first ink film layer (Y) contains an acrylic resin (A) having an acid value of 50 to 140 mgKOH / g, an organic pigment, and / or carbon black.
(2) The second ink film layer (Z) contains the polyurethane resin (B).
(3) The difference in acid value between the acrylic resin (A) and the polyurethane resin (B) is 90 KOHmg / g or less.

Furthermore, the present invention provides
The acid value of a polyurethane resin (B) is 25-50 KOHmg / g, It is related with the said printing ink laminated body characterized by the above-mentioned.

Furthermore, the present invention provides
The ink film layer (Y) and the ink film layer (Z) are formed by a flexographic printing method and relate to the printed material ink laminate.

  According to the present invention, the acid value of the acrylic resin and the polyurethane resin is defined, and the ink film layer made of each resin is used in an optimal combination, so that the overprint varnish layer is not used in the front print configuration, and the reverse print configuration is used. Can provide a printing ink laminate having various excellent film properties without an anchor coat varnish layer.

  Hereinafter, although the present invention will be described in detail, the description of the constituent elements described below is an example (representative example) of an embodiment of the present invention, and the present invention is not limited to these contents unless it exceeds the gist.

  The printing ink laminate in the present invention contains a plastic film (X), a first ink film layer (Y), and a second ink film layer (Z), and is used for printing (surface printing or back printing). (X), (Y), and (Z) are stacked in the optimal order. Furthermore, in back printing, a sealant film is laminated via an adhesive in addition to (X), (Y), and (Z).

  The printing ink laminate in the back printing configuration is formed by laminating a plastic film (X), a first ink film layer (Y), a second ink film layer (Z), and a sealant film in order through an adhesive. It is printing ink structure (I).

  The printing ink laminate in the front printing configuration is a printing ink construction (II) formed by laminating a plastic film (X), a second ink coating layer (Z), and a first ink coating layer (Y) in this order. is there.

  As the plastic film (X) in the present invention, stretched and unstretched polyolefins such as polypropylene, polyethylene, polystyrene, polyester, nylon, cellophane, vinylon, and the like can be used. In the case of a polyolefin film, it is preferable to use a surface-treated polyolefin film having a functional group such as a hydroxyl group or a carbonyl group.

  The first ink film layer (Y) in the present invention is an ink film layer formed from a printing ink (y) containing an acrylic resin (A), an organic pigment and / or carbon black. The printing ink (y) used is preferably aqueous.

  As the acrylic resin (A), an acrylic resin having an acid value of 50 to 140 mgKOH / g can be used. When the acid value is less than 50 mgKOH / g, the pigment dispersibility is lowered, so that the ink stability is deteriorated and the amount of ink transferred to the plastic film during printing is reduced. Therefore, the scratch resistance, blocking resistance, friction resistance, and water friction resistance of the printed coating film deteriorate. On the other hand, even when it exceeds 140 mgKOH / g, the dispersion / solubility of the acrylic resin in water is improved and the ink stability is improved, but the water friction resistance and the suitability for lamination are deteriorated. The acrylic resin (A) may be contained in an amount sufficient to ensure the stability of the ink and the physical properties of the coating film, that is, 10 to 35% by weight in terms of solid content in 100% by weight of the ink composition. preferable.

  Organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, isoindoline, etc. Pigments. From the viewpoint of coloring power, copper phthalocyanine is preferably used for the indigo ink. For transparent yellow ink, C.I. I. It is preferable to use PigmentNoYellow83. The organic pigment is preferably contained in an amount sufficient to ensure the concentration and coloring power of the ink, that is, 10 to 25% by weight in 100% by weight of the ink composition. With black ink, black ink can be obtained by mixing organic pigments, but carbon black is preferably used from the viewpoint of blackness.

  Printing ink (y) can also use an additive as needed. For example, additives such as leveling agents, antifoaming agents, waxes, silane coupling agents, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, and flame retardants can be used.

  The printing ink (y) can use an adhesion assistant. As the adhesion assistant, a compound containing a hydrazide group is preferable. An example is adipic acid dihydrazide (ADH). As will be described later, the adhesion to the plastic film and the strength of the ink film are improved by interacting with the keto group in the resin and the curing agent.

  Further, a curing agent can be used for the printing ink (y). Examples of the curing agent include resin fine particle dispersions containing reactive groups such as carbodiimide groups and keto groups. Commercially available reactive group-containing resin fine particle dispersions include, for example, Nisshinbo Co., Ltd., Carbodilite E-02, SV-02, V-02, V-02-L2, V-04, BASF, Acronal YJ2716D, YJ2720D. YJ2727DN, YJ2741D, YJ2746DS, manufactured by DSM Neoresin, NEOCRYLA-1127, A-1125, A-1120, A-1131, and the like.

  For the purpose of further improving the adhesion to the substrate and the ink film strength, the above curing agent should be used within a range that does not adversely affect the storage stability of the aqueous ink composition of the present invention and the compatibility between the resins. Can do. The addition amount is preferably about 0.5 to 15% by weight in terms of solid content in 100% by weight of the ink composition.

  In the printing ink (y), it is preferable to use water or alcohol as a solvent. Examples of alcohols include methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, and iso-butanol. When applied to food packaging materials, it is preferable to use ethanol, 1-propanol or 2-propanol as alcohols from the viewpoint of safety and hygiene and residual odor. Since the printing ink (y) in the present invention is a water-based ink, water alone and water and one or more of ethanol, 1-propanol or 2-propanol are mixed and used.

  Furthermore, ethylene glycol, diethylene glycol, propylene glycol, dipropylene glycol and their mono- or diethers can be used as necessary for the purpose of adjusting the drying.

  As the printing ink (y), an acrylic resin and another water-based resin can be used. Examples of the aqueous resin include polyester resin, polyamide resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, chlorinated polyolefin resin, and styrene maleic acid resin. The aqueous resin that can be used in combination is preferably used in an amount of about 0.5 to 15% by weight in terms of solid content in 100% by weight of the water-based ink composition.

  The second ink film layer (Z) in the present invention is an ink film layer formed from the printing ink (z) containing the polyurethane resin (B). The printing ink (z) is preferably aqueous. An inorganic pigment may be added to the printing ink (z).

It is preferable that the acid value of a polyurethane resin (B) is the range of 25-50 mgKOH / g.
When the acid value is less than 25 mgKOH / g, the dispersion and solubility of the polyurethane resin in water is poor, so that the ink stability is deteriorated and the amount of ink transferred to the plastic film during printing is reduced. Therefore, the scratch resistance, blocking resistance, friction resistance, and water friction resistance of the printed coating film deteriorate. Also, when the acid value exceeds 50 mgKOH / g, the dispersion and solubility of the polyurethane resin in water is good and the stability is improved, but the water friction resistance is deteriorated. The urethane resin (B) may be contained in an amount sufficient to ensure ink stability and physical properties of the coating film, that is, in a proportion of 10 to 35% by weight in terms of solid content in 100% by weight of the ink composition. preferable.

  Examples of the inorganic pigment include titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, and silica. It is preferable that the inorganic pigment is contained in an amount sufficient to ensure the concentration and coloring power of the ink, that is, in a ratio of 10 to 50% by weight in 100% by weight of the ink composition in the printing ink.

  Additives, adhesion assistants, curing agents, and solvents used as necessary for the printing ink (z) may be the same as those described for the printing ink (y).

  As the printing ink (z), urethane resin and other water-based resin can be used. Examples of the aqueous resin include polyester resin, polyamide resin, vinyl chloride resin, vinyl chloride-vinyl acetate copolymer resin, ethylene-vinyl acetate copolymer resin, chlorinated polyolefin resin, and styrene maleic acid resin. The aqueous resin that can be used in combination is preferably used in an amount of about 0.5 to 15% by weight in terms of solid content in 100% by weight of the water-based ink composition.

The printing ink (y) and the printing ink (z) can be produced by using the above-mentioned raw materials using a commonly used disperser such as a roller mill, a ball mill, a pebble mill, an attritor, a sand mill and the like.

  When bubbles or unexpectedly large particles are included in the printing ink, it is preferably removed by filtration or the like in order to reduce the quality of the printed matter. A conventionally well-known filter can be used.

  The viscosity of the printing ink is preferably in the range of 10 mPa · s or more from the viewpoint of preventing the pigment from settling and being appropriately dispersed, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production or printing. In addition, the said viscosity is a viscosity measured at 25 degreeC with the Tokimec B-type viscometer.

  As the printing coating method, a known flexographic printing method and gravure printing method can be applied. The thickness of the printing ink layer is preferably printed or applied so as to be about 0.1 to 5 μm in a dry state. More preferably, it is about 0.1 to 2 μm.

  In the printing ink structure (I) (back printing structure) and the printing ink structure (II) (surface printing structure), excellent film properties are obtained by laminating ink film layers composed of different resin systems in the prescribed order. (Tape adhesion, laminating suitability, water friction resistance, etc.) can be obtained. When an ink film layer made of the same type of resin is laminated, the physical properties of the coating film deteriorate.

  In the printing ink structure (I) (back printing structure), when the ink film layers made of acrylic resin are laminated, the flexibility of the ink laminated body is lowered, so that the laminating suitability is deteriorated. When the ink film layers made of polyurethane resin are laminated, scratch resistance and blocking resistance are deteriorated. On the other hand, when the ink film layers comprising urethane acrylic resin or a mixed system of urethane resin and acrylic resin are laminated, the suitability for lamination deteriorates.

  In the printing ink construction (II) (surface printing construction), when the ink film layers made of acrylic resin are laminated, the flexibility of the ink laminated body is lowered, so that the tape adhesion and the sag resistance are deteriorated. On the other hand, when the ink film layers made of polyurethane resin are laminated, scratch resistance and blocking resistance deteriorate. Furthermore, since the film | membrane intensity | strength of an ink laminated body is low, friction resistance, scratch resistance, and blocking resistance deteriorate. On the other hand, when the ink film layers composed of urethane acrylic resin or a mixed system of urethane resin and acrylic resin are laminated, tape adhesion, friction resistance and the like deteriorate.

  In the present invention, the acrylic resin (A) contained in the ink film layer (Y) and the polyurethane resin (B) contained in the ink film layer (Z) are different in acid value (acid of the acrylic resin (A)). (The acid value of the polyurethane resin (B)) can be used in a combination of 90 mgKOH / g or less. When the acid value difference exceeds 90 mgKOH / g, in the printing ink construction (I) (back printing construction), the tape adhesion and laminating suitability deteriorate, and in the printing ink construction (II) (front printing construction). Deteriorates water rub resistance and sag resistance.

  Furthermore, a difference in polarity occurs due to the difference between the resin system of the base ink applied first and the base ink applied later, and the trapping of the same resin system is better than that of overprinting. . The trapping means a state in which the upper ink spreads out when the ink is printed on the base ink. By forming a uniform printed film, the physical properties of the coating film are improved.

  The printing ink structure (I) (back printing structure) in the present invention is obtained by laminating a printed material and a sealant film through an adhesive and then aging. There are various processing methods for laminating, but typical examples include a non-sol laminating method (NL), a dry laminating method (DL), and an extrusion laminating method (EL).

  The non-sol laminating method is a method in which a solvent-free adhesive is applied to the printing surface of the obtained printed matter and is laminated by pressing with a sealant. As the adhesive, a two-component type of polyol / isocyanate is mainly used, and specific examples include EA-N373A / EA-N373B manufactured by Toyo Morton. Examples of the sealant include the above-described various films, paper, aluminum foil, or a film or sheet made of a composite material thereof. Specifically, there are TUX-FCD (LLDPE) manufactured by Mitsui Chemicals Tosero Co., Ltd., ZK93KM (CPP) manufactured by Toray Industries, Inc., Dialeraster (VMPET) manufactured by Reiko, 2203 (VMPP) manufactured by Toray Industries, Inc., and the like.

  The dry laminating method is a method in which an adhesive is diluted to an appropriate viscosity with an organic solvent, applied to the printed surface of the obtained printed matter, dried and then pressure bonded to a sealant for lamination. As the adhesive, a two-component type of polyol / isocyanate is mainly used. Specifically, TM-250HV / CAT-RT86L-60, TM-550 / CAT-RT37, TM-314 / CAT-14B manufactured by Toyo Morton Co., Ltd. Etc. As the sealant, the same sealant as that used in the non-sol laminating method can be used.

The extrusion laminating method is a method in which a thermoplastic resin is melted on the printing surface of the obtained printed matter and extruded from a slit-like die called a T die into a film shape and laminated on a substrate. In many cases, an anchor coating agent is applied in advance to the printed surface of a printed material and then laminated. It is also possible to extrude the molten resin onto the printed surface of the printed material and bond the sealant from another unwinder. Anchor coating agents include imine, butadiene,
Isocyanate-based anchor coating agents can be used. Specific examples include EL-420 (imine type), EL-452 (butadiene type), EL-530A / B (isocyanate type), EL-540 / CAT-RT32 (isocyanate type), manufactured by Toyo Morton. It is done. As the molten resin, low density polyethylene, polypropylene, ethylene-vinyl acetate copolymer and the like can be used. Specific examples include Novatec LD LC600A (low density polyethylene) manufactured by Nippon Polyethylene. As the sealant, the same sealant as that used in the non-sol laminating method can be used.

  The printing ink structure (I) (back printing structure) obtained by the above method becomes a packaging bag by heat-sealing the sealant surfaces. Therefore, a film for imparting heat sealability is used for the sealant that hits the innermost side in the packaging bag. For example, polyolefin such as unstretched polyethylene or polypropylene can be used.

Method for Using Printing Ink Constituent (II) Also in the printing ink laminate (II) (surface printing configuration), the non-printing surface can be processed as a packaging material by using a heat-sealable film. Specific examples of the heat-sealable film include FOH manufactured by Futamura Chemical Co., P3162 manufactured by Toyobo.

  Subsequently, the acrylic resin (A) of the present invention will be described. Examples of the acrylic resin (A) of the present invention include a water-soluble acrylic resin (A-1) and an emulsion type (hereinafter abbreviated as Em type) acrylic resin (A-2).

  As the acrylic resin (A) in the present invention, a water-soluble acrylic resin (A-1) or an Em-type acrylic resin (A-2) may be used alone, or a mixture of two or more of these may be used. .

  The acid value in the case of the said mixture shall be computed from the sum of the product of the acid value of each used acrylic resin, and a weight ratio.

  First, the water-soluble acrylic resin (A-1) will be described. The water-soluble acrylic resin (A-1) can be obtained by solution polymerization or bulk polymerization according to a conventionally known method.

  Examples of the method for producing the water-soluble acrylic resin (A-1) include styrene- (meth) acrylic acid- (meth) acrylic acid alkyl ester copolymers. An organic solvent is charged into the reaction vessel and the temperature is raised. Any organic solvent can be used as long as it does not adversely affect the reaction and the subsequent treatment and can dissolve the obtained resin. After raising the temperature, radical polymerization is performed by adding a radical initiator while dropping styrene, (meth) acrylic acid, and (meth) acrylic acid alkyl ester under a nitrogen atmosphere. About the obtained resin solution, after neutralizing with a basic compound, it may be diluted with ion-exchanged water as it is, or the organic solvent may be replaced with ion-exchanged water. A water-soluble acrylic resin can be obtained by the above steps.

The water-soluble acrylic resin (A-1) preferably has an aromatic skeleton and a carboxyl group from the viewpoint of good water friction resistance and scratch resistance in the laminate. Aromatic ethylenically unsaturated monomer (a-1), carboxyl group-containing ethylenically unsaturated monomer (a-2) and ethylenically unsaturated monomer (a-3) copolymerizable therewith The ethylenically unsaturated monomer (a) can be obtained by solution polymerization or bulk polymerization with a radical initiator.
The obtained resin can be made aqueous by neutralization with a basic compound.

  Examples of the aromatic ethylenically unsaturated monomer (a-1) include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, m-methylstyrene, vinylnaphthalene, benzyl acrylate, benzyl methacrylate, Examples include phenoxyethyl acrylate, phenoxyethyl methacrylate, phenoxydiethylene glycol acrylate, phenoxydiethylene glycol methacrylate, phenoxytetraethylene glycol acrylate, phenoxytetraethylene glycol methacrylate, phenoxyhexaethylene glycol acrylate, phenoxyhexaethylene glycol methacrylate, phenyl acrylate, and phenyl methacrylate.

  Examples of the carboxyl group-containing ethylenically unsaturated monomer (a-2) include maleic acid, fumaric acid, itaconic acid, citraconic acid, or alkyl or alkenyl monoesters thereof, hexahydrophthalic acid β- (meta ) Acryloxyethyl monoester, β- (meth) acryloxyethyl monoester succinic acid, acrylic acid, methacrylic acid, crotonic acid, cinnamic acid and the like. In the range which does not deviate from content of the aromatic ethylenically unsaturated monomer (a-1) defined above and the ethylenically unsaturated monomer (a-2), An ethylenically unsaturated monomer (a-3) copolymerizable therewith can be used in combination.

  Examples of the copolymerizable ethylenically unsaturated monomer (a-3) include methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, t-butyl methacrylate, pentyl (meth) acrylate, and heptyl (meth). Acrylate, hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, decyl (meth) acrylate, undecyl (meth) acrylate, dodecyl (meth) acrylate, tridecyl (meth) Straight chain or branched alkyl group-containing ethylenically unsaturated monomers such as acrylate and tetradecyl (meth) acrylate; cycloaliphatic alkyl groups such as cyclohexyl (meth) acrylate and isobornyl (meth) acrylate Ethylenically unsaturated monomers; fluorinated alkyl group-containing ethylenically unsaturated monomers such as trifluoroethyl (meth) acrylate and heptadecafluorodecyl (meth) acrylate; (meth) acrylamide, N-methoxymethyl- (Meth) acrylamide, N-ethoxymethyl- (meth) acrylamide, N-propoxymethyl- (meth) acrylamide, N-butoxymethyl- (meth) acrylamide, N-pentoxymethyl- (meth) acrylamide, N, N- Di (methoxymethyl) acrylamide, N-ethoxymethyl-N-methoxymethylmethacrylamide, N, N-di (ethoxymethyl) acrylamide, N-ethoxymethyl-N-propoxymethylmethacrylamide, N, N-di (propoxymethyl) ) Acrylamide, N- Toximethyl-N- (propoxymethyl) methacrylamide, N, N-di (butoxymethyl) acrylamide, N-butoxymethyl-N- (methoxymethyl) methacrylamide, N, N-di (pentoxymethyl) acrylamide, N- Amido group-containing ethylenic groups such as methoxymethyl-N- (pentoxymethyl) methacrylamide, N, N-dimethylaminopropylacrylamide, N, N-diethylaminopropylacrylamide, N, N-dimethylacrylamide, N, N-diethylacrylamide Unsaturated monomer: 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 4-hydroxybutyl (meth) acrylate, glycerol mono (meth) acrylate, 4-hydroxyvinylbenzene, 1 -Ethynyl-1-cyclohexanol, hydroxyl group-containing ethylenically unsaturated monomers such as allyl alcohol; keto group-containing ethylenically unsaturated monomers such as diacetone (meth) acrylamide, acetoacetoxy (meth) acrylate; Is mentioned.

  As the radical initiator, a known oil-soluble polymerization initiator can be used. For example, benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert-butyl peroxy (2-ethylhexanoate), organic peroxides such as tert-butylperoxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide; 2,2′-azobisisobutyronitrile, 2,2′-azobis- Examples include azobis compounds such as 2,4-dimethylvaleronitrile, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1'-azobis-cyclohexane-1-carbonitrile. .

  Basic compounds used as neutralizing agents include ammonia; monoethylamine, diethylamine, trimethylamine, triethylamine, triisopropylamine, tributylamine, triethanolamine, methyldiethanolamine, monoethanolamine, dimethylethanolamine, diethylethanolamine, morpholine. Organic amines such as N-methylmorpholine and 2-amino-2-ethyl-1-propanol; inorganic alkalis such as sodium hydroxide and potassium hydroxide, and the like. However, in order to improve the water friction resistance of the printed coating film after drying, water-soluble and highly volatile substances that are easily dissociated by heat are preferable. Particularly, ammonia, dimethylethanolamine, trimethylamine are preferred. Triethylamine is preferred.

  The aromatic ethylenically unsaturated monomer (a-1) is preferably 10 to 70% by weight in 100% by weight of the ethylenically unsaturated monomer. If it is less than 10% by weight, the pigment dispersibility is lowered and the storage stability of the ink is lowered. On the other hand, even when it exceeds 70% by weight, the dispersibility of the water-soluble acrylic resin (A-1) is reduced, so that agglomerates are easily generated and the resin stability is lowered. As a result, the storage stability of the ink and the physical properties of the coating film are adversely affected.

  In 100% by weight of the ethylenically unsaturated monomer, the carboxyl group-containing ethylenically unsaturated monomer (a-2) is preferably 10 to 40% by weight. When the content is less than 10% by weight, the dispersibility of the water-soluble acrylic resin (A-1) is reduced, so that aggregates are likely to be generated, and the storage stability of the ink is deteriorated. On the other hand, if it exceeds 40% by weight, the physical properties of the coating film deteriorate due to the occurrence of poor drying in the printed coating film and the increase of components eluted into water.

  Furthermore, it is preferable that the weight average molecular weights (Mw) of water-soluble acrylic resin (A-1) are 5000-30000. If the weight average molecular weight is less than 5,000, the dispersion stability of the resin fine particle dispersion may be lowered, and the storage stability of the ink may be lowered, or the physical properties of the coating film may be adversely affected due to an increase in components eluted in water. is there. On the other hand, even when the weight average molecular weight (Mw) exceeds 30000, the viscosity is remarkably increased, and the storage stability of the ink may be lowered or the physical properties of the coating film may be adversely affected. The weight average molecular weight (Mw) here refers to a value in terms of polystyrene by GPC (gel permeation chromatography) measurement.

  Next, the Em type acrylic resin (A-2) will be described. The Em type acrylic resin (A-2) can be obtained by emulsion polymerization of the ethylenically unsaturated monomer (a-4) using a surfactant or a polymer dispersant as an emulsifier. Among these, from the viewpoint of excellent film resistance of the laminate, it is preferable to use an Em type acrylic resin using the water-soluble acrylic resin as an emulsifier.

  Specifically, the manufacturing method of Em type acrylic resin which uses water-soluble acrylic resin (A-1) for a polymer emulsifier is mentioned. First, an aqueous medium and a water-soluble acrylic resin (A-1) are charged into a reaction tank, and dissolved by heating. Thereafter, a radical polymerization initiator is added while dropping the ethylenically unsaturated monomer (a-4) under a nitrogen atmosphere. Since the color of the solution in the reaction vessel turns pale after the reaction starts, the formation of particle nuclei can be confirmed. The target Em type acrylic resin (A-2) can be obtained by further reacting for several hours after the completion of dropping of the ethylenically unsaturated monomer. The ethylenically unsaturated monomer may be added dropwise to the reaction vessel as it is, or it may be added dropwise after previously emulsifying with an aqueous medium. The water-soluble acrylic resin (A-1) functions as a protective colloid (shell component) in an aqueous medium and stabilizes the generated particle core (core component). The Em-type acrylic resin obtained by this method has a viscosity close to Newtonian, and thus is very excellent in printability.

  Examples of the ethylenically unsaturated monomer (a-4) include the aromatic ethylenically unsaturated monomer (a-1), the carboxyl group-containing ethylenically unsaturated monomer (a-2), Examples thereof include a copolymerizable ethylenically unsaturated monomer (a-3) and a crosslinkable ethylenically unsaturated monomer.

Examples of the crosslinkable ethylenically unsaturated monomer include:
Allyl (meth) acrylate, 1-methylallyl (meth) acrylate, 2-methylallyl (meth) acrylate, 1-butenyl (meth) acrylate, 2-butenyl (meth) acrylate, 3-butenyl (meth) acrylate, 1,3- Methyl-3-butenyl (meth) acrylate, 2-chloroallyl (meth) acrylate, 3-chloroallyl (meth) acrylate, o-allylphenyl (meth) acrylate, 2- (allyloxy) ethyl (meth) acrylate, allyl lactyl (meth) Acrylate, citronellyl (meth) acrylate, geranyl (meth) acrylate, rosinyl (meth) acrylate, cinnamyl (meth) acrylate, diallyl maleate, diallyl itaconic acid, vinyl (meth) acrylate, vinyl crotonic acid Vinyl oleate, vinyl linolenate, 2- (2′-vinyloxyethoxy) ethyl (meth) acrylate, ethylene glycol di (meth) acrylate, triethylene glycol (meth) acrylate, tetraethylene glycol (meth) acrylate, trimethylol Propane tri (meth) acrylate, pentaerythritol tri (meth) acrylate, 1,1,1-trishydroxymethylethane diacrylate, 1,1,1-trishydroxymethylethane triacrylate, 1,1,1-trishydroxymethyl Ethylenically unsaturated monomers having two or more ethylenically unsaturated groups such as propane triacrylate, divinylbenzene, divinyl adipate, diallyl isophthalate, diallyl phthalate, diallyl maleate;
Epoxy group-containing ethylenically unsaturated monomers such as glycidyl (meth) acrylate and 3,4-epoxycyclohexyl (meth) acrylate; γ-methacryloxypropyltrimethoxysilane, γ-methacryloxypropyltriethoxysilane, γ-methacrylic Roxypropyltributoxysilane, γ-methacryloxypropylmethyldimethoxysilane, γ-methacryloxypropylmethyldiethoxysilane, γ-acryloxypropyltrimethoxysilane, γ-acryloxypropyltriethoxysilane, γ-acryloxypropylmethyldimethoxy Silane, γ-methacryloxymethyltrimethoxysilane, γ-acryloxymethyltrimethoxysilane, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltributoxysilane, vinylmethyl Alkoxysilyl group-containing ethylenically unsaturated monomers such as dimethoxysilane; methylol group-containing ethylene such as N-methylol (meth) acrylamide, N, N-dimethylol (meth) acrylamide, alkyl etherified N-methylol (meth) acrylamide Although an unsaturated monomer is mentioned, it is not specifically limited to these. These can be used alone or in combination of two or more.

  Among the copolymerizable ethylenically unsaturated monomers (a-4) shown above, by using the keto group-containing ethylenically unsaturated monomer in combination, the tape adhesion of the ink film and the water friction resistance can be improved. It can be further improved by a synergistic effect. Keto groups derived from ethylenically unsaturated monomers react with hydrazide compounds in the ink composition to form keto-hydrazide bridges upon drying.

  It is preferable that 1-3 weight% of keto group containing ethylenically unsaturated monomers are contained in 100 weight% of ethylenically unsaturated monomers. If it is less than 1% by weight, the effect of crosslinking may not be confirmed in the physical properties of the coating film. On the other hand, when it exceeds 3% by weight, the compatibility of the shell component and the core component is deteriorated, and on the contrary, the physical properties of the coating film may be adversely affected.

  The polymerization initiator used for obtaining the emulsion type acrylic resin (A-2) used in the present invention is not particularly limited as long as it has the ability to initiate radical polymerization, and known oil-soluble polymerization initiators and A water-soluble polymerization initiator can be used.

  The oil-soluble polymerization initiator is not particularly limited, and examples thereof include benzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl hydroperoxide, tert-butyl peroxy (2-ethylhexanoate), and tert-butyl peroxide. Organic peroxides such as oxy-3,5,5-trimethylhexanoate, di-tert-butyl peroxide; 2,2′-azobisisobutyronitrile, 2,2′-azobis-2,4- Mention may be made of azobis compounds such as dimethylvaleronitrile, 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1′-azobis-cyclohexane-1-carbonitrile. These can be used alone or in combination of two or more.

  In the present invention, a water-soluble polymerization initiator is preferably used. For example, ammonium persulfate (APS), potassium persulfate (KPS), hydrogen peroxide, 2,2′-azobis (2-methylpropionamidine) dihydro Conventionally known materials such as chloride can be preferably used.

  Moreover, when performing emulsion polymerization, a reducing agent can be used together with a polymerization initiator if desired. Thereby, it becomes easy to accelerate the emulsion polymerization rate or to perform the emulsion polymerization at a low temperature.

  Examples of such a reducing agent include reducing organic compounds such as metal salts such as ascorbic acid, ersorbic acid, tartaric acid, citric acid, glucose, formaldehyde sulfoxylate, sodium thiosulfate, sodium sulfite, sodium bisulfite, Examples include reducing inorganic compounds such as sodium bisulfite, ferrous chloride, Rongalite, thiourea dioxide, and the like. These reducing agents are preferably contained in an amount of 0.05 to 5.0% in 100% by weight of the ethylenically unsaturated monomer. In addition, it can superpose | polymerize also by a photochemical reaction, radiation irradiation, etc. irrespective of an above described polymerization initiator. The polymerization temperature is not less than the polymerization start temperature of each polymerization initiator. For example, in the case of a peroxide-based polymerization initiator, it may be usually about 80 ° C. The polymerization time is not particularly limited, but is usually 2 to 24 hours.

  Further, if necessary, sodium acetate, sodium citrate, sodium bicarbonate, etc. as a buffering agent, and octyl mercaptan, 2-ethylhexyl thioglycolate, octyl thioglycolate, stearyl mercaptan, lauryl mercaptan as a chain transfer agent A suitable amount of mercaptans such as t-dodecyl mercaptan can be used.

  When obtaining the Em type acrylic resin used in the present invention by radical polymerization, various surfactants can be used in addition to the water-soluble acrylic resin (A-1). These can be used alone or in combination of two or more.

Examples of the surfactant include alkyl ethers (commercially available products include, for example, Aqualon KH-05, KH-10, KH-20, manufactured by Daiichi Kogyo Seiyaku Co., Ltd., ADEKA rear soap SR-10N, SR manufactured by ADEKA CORPORATION. -20N, LATEMUL PD-104 manufactured by Kao Corporation), sulfosuccinic acid ester type (commercially available products include LATEMUL S-120, S-120A, S-180P, S-180A, Sanyo Chemical Co., Ltd. manufactured by Kao Corporation) Company-made Eleminol JS-2 etc.), alkyl phenyl ether type or alkyl phenyl ester type (commercially available products include, for example, Aqualon H-2855A, H-3855B, H-3855C, H, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.)
-3856, HS-05, HS-10, HS-20, HS-30, ADEKA Corporation ADEKA rear soap SDX-222, SDX-223, SDX-232, SDX-233, SDX-259, SE-10N, SE-20N, etc.), (meth) acrylate sulfate system (commercially available products include, for example, Nippon Emulsifier Co., Ltd. Antox MS-60, MS-2N, Sanyo Chemical Industries Co., Ltd., Eleminol RS-30, etc.), Anionic reactive emulsifiers such as phosphate esters (for example, H-3330PL manufactured by Daiichi Kogyo Seiyaku Co., Ltd., ADEKA rear soap PP-70 manufactured by ADEKA Co., Ltd.);

Higher fatty acid salts such as sodium oleate, alkylaryl sulfonates such as sodium dodecylbenzene sulfonate, alkyl sulfate salts such as sodium lauryl sulfate, polyoxyethylene alkyl ether sulfate salts such as sodium polyoxyethylene lauryl ether sulfate, Polyoxyethylene alkylaryl ether sulfates such as sodium polyoxyethylene nonylphenyl ether sulfate, alkyl sulfosuccinates such as sodium monooctyl sulfosuccinate, sodium dioctyl sulfosuccinate, sodium polyoxyethylene lauryl sulfosuccinate and derivatives thereof, Anionic non-reactive emulsification of polyoxyethylene distyrenated phenyl ether sulfates ;

Polyoxyethylene alkyl ethers such as polyoxyethylene lauryl ether and polyoxyethylene stearyl ether, polyoxyethylene alkyl phenyl ethers such as polyoxyethylene octylphenyl ether and polyoxyethylene nonylphenyl ether, sorbitan monolaurate, sorbitan mono Sorbitan higher fatty acid esters such as stearate and sorbitan trioleate, polyoxyethylene sorbitan higher fatty acid esters such as polyoxyethylene sorbitan monolaurate, polyoxyethylene such as polyoxyethylene monolaurate and polyoxyethylene monostearate Glycerin higher fatty acid ester such as higher fatty acid esters, oleic acid monoglyceride, stearic acid monoglyceride Le ethers, polyoxyethylene polyoxypropylene block copolymer, nonionic non-reactive emulsifier polyoxyethylene distyrenated phenyl ether; and the like.

  The average particle diameter of the Em type acrylic resin (A-2) is preferably in the range of 30 to 80 nm. When the average particle size is less than 30 nm, the dispersion stability of the Em type acrylic resin in the ink composition is lowered, which adversely affects the storage stability of the ink. On the other hand, when it exceeds 80 nm, the film formation at the time of drying becomes insufficient, and the physical properties of the coating film (tape adhesion, water rub resistance, blocking resistance) deteriorate. The average particle diameter referred to here is a volume average measured by a dynamic light scattering method in which a water dilution of an Em type acrylic resin (A-2) is irradiated with laser light and the Brownian motion of the particles is detected from the scattered light. It is the value of the particle diameter.

  The glass transition temperature (Tg) of the Em type acrylic resin (A-2) is preferably in the range of 10 to 65 ° C. When the Tg is less than 10 ° C., the strength of the ink film is lowered and the coating film properties (tape adhesion, water friction resistance, blocking resistance) are deteriorated. On the other hand, even when the glass transition temperature exceeds 65 ° C., the movement of the molecular chain under low temperature drying is inhibited, so that the film formation and the compatibility of the core component and the shell component become insufficient, and the coating film properties (tape Adhesion and water friction resistance) deteriorate.

  The weight average molecular weight (Mw) of the Em type acrylic resin (A-2) is preferably in the range of 100,000 to 600,000. When the weight average molecular weight is less than 100,000, the stability of the resin fine particles in the ink solvent is lowered, so that the film strength of the ink laminate is lowered and the film properties (tape adhesion, water friction resistance, blocking resistance) are reduced. ) May get worse. On the other hand, when the molecular weight exceeds 600,000, the movement of the molecular chain under low temperature drying is inhibited, so the film formation and the compatibility of the core component and the shell component become insufficient, and the coating film resistance (tape adhesion, water friction resistance). May get worse.

Next, the polyurethane resin (B) used in the present invention will be described.
The polyurethane resin (B) is not particularly limited, but can be obtained by subjecting a polyol and a polyisocyanate to a polyaddition reaction according to a conventionally known method.

  Typical examples of the polyol used as the raw material for the polyurethane resin (B) include polyester polyol, polyether polyol, and polycarbonate polyol.

  Examples of the polyester polyol include a polyester polyol obtained by condensation reaction of a polyol component and a dibasic acid component. Among the polyols, diols include ethylene glycol, propylene glycol, dipropylene glycol, diethylene glycol, triethylene glycol, butylene glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, and 3,3′-diene. Methylol heptane, polyoxyethylene glycol, polyoxypropylene glycol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, octanediol, butylethylpentanediol, 2-ethyl-1,3-hexanediol, Examples of the polyol having three or more hydroxyl groups include glycerin, trimethylolpropane, pentaerythritol, and the like as dibasic acid components. Examples thereof include aliphatic or aromatic dibasic acids such as terephthalic acid, adipic acid, azelaic acid, sebacic acid, dimer acid, hydrogenated dimer acid, phthalic anhydride, isophthalic acid and trimellitic acid, and anhydrides thereof. Moreover, the polyester polyol obtained by ring-opening polymerization of cyclic ester compounds, such as lactones, such as (epsilon) -caprolactone, poly ((beta) -methyl-gamma-valerolactone), and polyvalerolactone, is mentioned.

  Examples of the polyether polyol include tetrahydrofuran, or a polymer, copolymer or graft copolymer of alkylene oxide such as tetrahydrofuran, ethylene oxide, propylene oxide, butylene oxide, hexanediol, methylhexanediol, heptanediol, octanediol, or Those having two or more hydroxyl groups, such as polyether polyols obtained by condensation of these mixtures and polyether polyols which are propoxylated or ethoxylated, can be used. Among these, an ethylene oxide polymer (polyethylene glycol) is introduced into the resin skeleton as a hydrophilic group.

  Examples of the polycarbonate polyol include those obtained by a reaction between a polyol and a carbonate compound such as dialkyl carbonate, alkylene carbonate, and diaryl carbonate. As a polyol which comprises a polycarbonate polyol, the polyol illustrated previously as a structural component of a polyester polyol can be used. Examples of the dialkyl carbonate include dimethyl carbonate and diethyl carbonate, examples of the alkylene carbonate include ethylene carbonate, and examples of the diaryl carbonate include diphenyl carbonate.

  In addition, polybutadiene polyol, acrylic polyol, polysiloxane polyol, castor oil polyol, and the like are also included.

  These polyols may use only 1 type, or may use multiple types together.

  In order to dissolve or disperse the polyurethane resin in the aqueous medium, it is necessary to introduce a hydrophilic group into the resin skeleton. The polyethylene glycol mentioned above is also useful as a hydrophilic group, but in order to dissolve or disperse it in an aqueous medium only with an ethylene oxide chain, it must be introduced in a large amount into the resin skeleton. In that case, since the water resistance of the resin coating is significantly reduced, the water friction resistance of the laminate is also significantly deteriorated. Therefore, a polyol having an anionic group is used for introducing a hydrophilic group. Among the polyols having an anionic group, it is desirable to use a polyol having a carboxyl group from the viewpoint of excellent resistance after drying.

  Examples of the polyol having a carboxyl group include dimethylolacetic acid, dimethylolpropionic acid, dimethylolbutanoic acid, 2,2-dimethylolbutyric acid, dimethylolalkanoic acid such as 2,2-dimethylolpentanoic acid, dihydroxysuccinic acid, Examples include dihydroxypropionic acid and dihydroxybenzoic acid. These carboxyl group-containing polyols can be used alone or in combination.

  In addition to the above polyols, low molecular polyols can be used in combination as appropriate for the purpose of increasing the urethane bond concentration in the resin skeleton or introducing a branched structure or tertiary amino group into the resin.

As a low molecular polyol, for example,
Ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, hexanediol, 1,4-cyclohexanedimethanol, octane Diol, 2-butyl-2-ethyl-1,3-propanediol, 1,4-butylenediol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-butanetriol, pentaerythritol, And sorbitol, N, N-bis (2-hydroxypropyl) aniline, and the like.

  Furthermore, it is also possible to introduce an ethylenically unsaturated group into the urethane skeleton by using an ethylenically unsaturated monomer having at least two hydroxyl groups and one unsaturated group in the same molecule. .

  Examples of the ethylenically unsaturated monomer having at least two hydroxyl groups and one unsaturated group in the same molecule include a reaction product of glycidol and acrylic acid, a reaction of triol, diisocyanate and 2-hydroxymethacrylate. Thing etc. are mentioned.

  As the polyisocyanate to be reacted with the polyol, aromatic, aliphatic and alicyclic polyisocyanates are used.

  Examples of the aromatic polyisocyanate include 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, 4,4′-diphenylmethane diisocyanate, xylylene diisocyanate, lysine diisocyanate, 3,3′-dimethyl-4,4′-biphenylene diisocyanate, 3,3′-dimethoxy-4,4′-biphenylene diisocyanate, 3,3′-dichloro-4,4′-biphenylene diisocyanate, 1,5-naphthalene Examples thereof include diisocyanate and 1,5-tetrahydronaphthalene diisocyanate.

  Examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, hexamethylene diisocyanate, and trimethylhexamethylene diisocyanate.

  Examples of the alicyclic polyisocyanate include, but are not limited to, isophorone diisocyanate, 1,4-cyclohexylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, and the like. These may use only 1 type or may use multiple types together.

  Catalysts used for the reaction of isocyanate and hydroxyl group include dibutyltin dilaurate, tin octoate, dibutyltin di (2-ethylhexoate), lead 2-ethylhexoate, 2-ethylhexyl titanate, titanium ethyl acetate, Examples include 2-ethylhexoate iron, 2-ethylhexoate cobalt, zinc naphthenate, cobalt naphthenate, tetra-n-butyltin, stannous chloride, stannic chloride, and iron chloride.

  The urethane resin used in the present invention may undergo a chain extension reaction as necessary. In the chain extension reaction, after producing an isocyanate group-excess urethane prepolymer, a bifunctional or higher functional hydrogen-containing compound that reacts with an isocyanate group, such as diamine, is reacted as a chain extender. This reaction is preferably performed when the resin is neutralized and made aqueous, from the viewpoint of significant thickening of the resin solution. By chain extension, it is possible to further increase the molecular weight of the polyurethane resin. In addition, by introducing a urea bond, further improvement in the cohesive strength of the resin can be expected. Therefore, various coating film resistance of the laminated body using this resin is also improved.

Examples of chain extenders include:
Diamines such as hydrazine, ethylenediamine, propylenediamine, hexamethylenediamine, nonamethylenediamine, xylylenediamine, isophoronediamine, piperazine and derivatives thereof, phenylenediamine, tolylenediamine, xylenediamine, adipic acid dihydrazide, isophthalic acid dihydrazide;
Triamines such as diethylenetriamine;
Ethylene glycol, propylene glycol, 1,4-butanediol, 1,6-hexanediol, 1,4-bis (β-hydroxyethoxy) benzene, 1,4-cyclohexanediol, bis (β-hydroxyethyl) terephthalate, xylyl Diols such as lenglycol;
Triols such as trimethylolpropane;
Pentaols such as pentaerythritol;
Known chain extenders such as amino alcohols such as N- (β-aminoethyl) ethanolamine can be used.
When a monofunctional monoamine or monool is used in combination, the molecular weight can be controlled by stopping the chain extension.

  The ethylene oxide unit content (hereinafter abbreviated as EO%) of the polyurethane resin (B) is preferably in the range of 4-40. When the EO% is less than 5, in addition to the same problem as the case where the acid value is less than 25, the trapping property between the ink film layers is lowered due to the low new water content, so that the physical properties of the coating film are deteriorated. . Moreover, when EO% exceeds 40, water friction resistance and tape adhesiveness are inferior, and furthermore, the viscosity of the polyurethane resin (B) becomes high and the effective amount of the binder in the ink becomes too small. Cause inviting problems. EO% is a solid content weight ratio of polyethylene glycol in the polyurethane resin (B).

  The polyurethane resin (B) solution can be produced by neutralizing the polyurethane resin thus obtained with a basic compound to make it aqueous, and removing the solvent as necessary.

  The weight average molecular weight of the polyurethane resin (B) is preferably in the range of 5,000 to 100,000. When the molecular weight of the polyurethane resin is less than 5,000, the formed printed coating film tends to be inferior in friction resistance and water friction resistance. When the molecular weight exceeds 100,000, the viscosity of the resulting aqueous printing ink increases. Since the effective amount of the binder is too small, there is a problem in that the strength of the printed coating film is reduced.

  As the basic compound for neutralizing the anionic group incorporated in the polyurethane resin (B), the same basic compound as used for neutralizing the water-soluble acrylic resin can be used.

Examples of the inert and hydrophilic organic solvent for the isocyanate used in the present invention include ethers such as tetrahydrofuran and dioxane, esters such as ethyl acetate, ketones such as acetone, methyl ethyl ketone, and cyclohexanone, dimethylformamide, Amides such as N-methylpyrrolidone, etc. are mentioned, but since the polyurethane is usually removed by distillation under reduced pressure, and even when used without solvent removal, the drying rate is increased. The use of a boiling solvent is desirable.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to these examples without departing from the technical idea of the present invention. In the examples, “part” represents “part by weight” and “%” represents “% by weight”.

<Production of water-soluble acrylic resin (A-1)>
[Production Example 1]
While introducing nitrogen gas into a reaction vessel equipped with a stirrer, a thermometer, two dropping funnels, and a refluxer, 95.0 parts of methyl isobutyl ketone was charged and the temperature was raised to 100 ° C. Next, in two dropping funnels, 60.0 parts of styrene, 30.0 parts of acrylic acid, and 10.0 parts of cyclohexyl methacrylate were dropped from one side over 3 hours. From the other side, 6.0 parts of dimethyl 2,2′-azobisisobutyrate was dissolved in 12.0 parts of methyl isobutyl ketone and added dropwise over 4 hours. After completion of the dropwise addition, the reaction was completed by further reacting for 10 hours. After cooling, the obtained water-soluble resin solution was neutralized by adding 23.3 parts of 25% aqueous ammonia. Further, ion exchange water was added, and solvent substitution was performed while heating to obtain a water-soluble acrylic resin (Ac1) solution. Finally, the solid content of the water-soluble acrylic resin (Ac1) solution was adjusted to 35.0% with ion-exchanged water. The acid value of the water-soluble acrylic resin (Ac1) was 220 mgKOH / g, the glass transition temperature (Tg) was 98 ° C., and the weight average molecular weight (Mw) was 15000.

  The acid value, glass transition temperature (Tg), and weight average molecular weight (Mw) were evaluated by the following methods.

[Acid value]
Number of milligrams of potassium hydroxide required to neutralize acidic components contained in 1 g of resin. The dried water-soluble acrylic resin (A-1) was calculated by performing potentiometric titration with a potassium hydroxide / ethanol solution according to the method described in JISK2501.

[Glass-transition temperature]
The glass transition temperature is the theoretical value calculated from the FOX equation below.
<FOX type> 1 / Tg = W1 / Tg1 + W2 / Tg2 + ... + Wi / Tgi + ... + Wn / Tgn
[In the above FOX formula, the glass transition temperature of the homopolymer of each monomer constituting the polymer composed of n types of monomers is Tgi (K), the mass fraction of each monomer is Wi, and (W1 + W2 + ... + Wi +... Wn = 1). ]

[Weight average molecular weight (Mw)]
The weight average molecular weight is a value in terms of polystyrene as measured by GPC (gel permeation chromatography). The dried resin was dissolved in tetrahydrofuran to prepare a 0.1% solution, and the weight average molecular weight was measured using the following apparatus and measurement conditions.
Apparatus: HLC-8320-GPC system (manufactured by Tosoh Corporation)
Column; TSKgel-SuperMultiporeHZ-M0021488
4.6 mm I.D. x 15 cm x 3 (molecular weight measurement range 2,000 to about 2 million)
Elution solvent; Tetrahydrofuran standard substance; Polystyrene (Tosoh Corporation)
Flow rate: 0.6 mL / min, sample solution usage: 10 μL, column temperature: 40 ° C.

[Production Examples 2 to 6]
A solution of a water-soluble acrylic resin (Ac2-6) was prepared in the same manner as in Production Example 1 with the composition shown in Table 1. 25% ammonia water as a neutralizing agent was added so that the carboxyl group of the water-soluble acrylic resin (Ac2-6) and ammonia were equimolar. Further, the same operation as in Production Example 1 was performed to prepare a water-soluble acrylic resin (Ac2-6) solution having a solid content of 35%. About the obtained water-soluble acrylic resin (Ac2-6), the acid value, the glass transition temperature (Tg), and the weight average molecular weight (Mw) were measured.

<Manufacture of Em type acrylic resin (A-2)>
[Production Example 7]
While introducing nitrogen gas into a reaction vessel equipped with a stirrer, a thermometer, two dropping funnels, and a refluxing vessel, 100.0 parts of ion-exchanged water and a water-soluble acrylic resin having a solid content of 35% prepared in Production Example 1 ( Ac1) 757.1 parts of solution was charged and the temperature was raised to 80 ° C. Next, in two dropping funnels, 20.0 parts of styrene, 20.0 parts of benzyl methacrylate, and 60.0 parts of n-butyl acrylate were dropped from one side over 2 hours. From the other side, 4.5 parts of a 20% aqueous solution of ammonium persulfate was added dropwise over 2 hours. After completion of dropping, the reaction was further continued for 4 hours to obtain an Em type acrylic resin (Ac7) solution. The solid content of the Em acrylic resin (Ac7) solution was adjusted to 35.0% with ion-exchanged water. The resulting Em type acrylic resin (Ac7) had an average particle size of 35 nm, a weight average molecular weight (Mw) of 200000, an acid value of 160 mgKOH / g, and a glass transition temperature of 61 ° C. About the obtained Em type acrylic resin (Ac7), the acid value, glass transition temperature (Tg), and weight average molecular weight (Mw) were evaluated by the method similar to manufacture example 1, and the average particle diameter was evaluated by the following method. .

[Average particle size]
The resin fine particle dispersion was diluted with water 500 times, and about 5 ml of the diluted solution was measured by a dynamic light scattering measurement method (measurement device manufactured by Nanotrack EX150 Nikkiso Co., Ltd.). The peak of the volume particle size distribution data (histogram) obtained at this time was defined as the average particle size.

[Production Examples 8 to 12]
An em-type acrylic resin (Ac8-12) solution was prepared in the same manner as in Production Example 7 with the formulation shown in Table 2, and the acid value, glass transition temperature (Tg), weight average molecular weight (Mw), average particle size Evaluated. For Production Examples 8 to 11, after the synthesis, adipic acid dihydrazide as a crosslinking agent was added so that the hydrazide group was equimolar with respect to the keto group in the Em type acrylic resin (Ac12). The solid content of the Em type acrylic resin (Ac8-12) solution was all adjusted to 35.0%.

<Manufacture of polyurethane resin (B)>
[Production Example 13]
While introducing nitrogen gas into a reaction vessel equipped with a thermometer, stirrer, reflux condenser, stirrer, and refluxer, PTG-3000SN (Hodogaya Chemical polytetramethylene glycol functional group number 2 number average molecular weight 3000) 11.5 Parts, PEG # 200 (NOF polyethylene glycol functional group number 2 number average molecular weight 2000) 2.3 parts, N, N-bis (2-hydroxypropyl) aniline 0.4 part, dimethylolpropionic acid 3.6 parts and 7.2 parts of isophorone diisocyanate was charged and reacted at 90 ° C. for 3 hours. After cooling, the resulting water-soluble resin is made water-soluble by gradually dropping and neutralizing a mixed solution of 1.6 parts of 25% aqueous ammonia and 75.0 parts of ion-exchanged water to obtain an aqueous solution of polyurethane resin (Ur1) Got. The resulting polyurethane resin (Ur1) had an acid value of 60 mgKOH / g, EO% of 9.2%, and a weight average molecular weight (Mw) of 36000. The acid value and the weight average molecular weight (Mw) were measured by the methods described above.

[Production Example 14]
While introducing nitrogen gas into a reaction vessel equipped with a thermometer, a stirrer, a reflux condenser, a stirrer, and a refluxer, PTG-3000SN (Hodogaya Chemical polytetramethylene glycol functional group number 2 number average molecular weight 3000) 7.4 Parts, PEG # 200 (NOF polyethylene glycol functional group number 2 number average molecular weight 2000) 3.0 parts, N, N-bis (2-hydroxypropyl) aniline 0.5 parts, dimethylolpropionic acid 3.0 parts, 9.6 parts of isophorone diisocyanate and 60.0 parts of methyl ethyl ketone were charged, heated to 80 ° C. and reacted for 3 hours. The obtained terminal isocyanate group urethane prepolymer solution was cooled to 40 ° C., and a mixed solution of 1.5 parts of N- (β-aminoethyl) ethanolamine and 40.0 parts of acetone was added dropwise over 30 minutes with stirring. The chain extension reaction was performed for 1 hour. Furthermore, 1.4 parts of 25% aqueous ammonia and 75.0 parts of ion exchange water were added, the temperature was raised, 100.0 parts were removed, and an aqueous solution of polyurethane resin (Ur2) was obtained. The resulting polyurethane resin (Ur2) had an acid value of 50 mgKOH / g, EO% of 12.0%, and a weight average molecular weight (Mw) of 38000. The acid value and the weight average molecular weight (Mw) were measured by the methods described above.

[Production Examples 15 to 18]
A polyurethane resin (Ur3-6) solution was prepared in the same manner as in Production Example 13 with the formulation shown in Table 3. 25% ammonia water as a neutralizing agent was added so that the carboxyl group of the polyurethane resin (Ur3-6) and ammonia were equimolar. About the obtained polyurethane resin (Ur3-6), the acid value and the weight average molecular weight were evaluated. The acid value and the weight average molecular weight (Mw) were measured by the methods described above.

<Manufacture of urethane acrylic resin>
[Production Example 19]
While introducing nitrogen gas into a reaction vessel equipped with a stirrer, a thermometer, and a refluxer, 59.7 parts of C-2090 (Kuraray MPD / HD / PC-based polycarbonate polyol, functional group number 2 average molecular weight 2000), dimethylol 17.7 parts of butanoic acid and 43.0 parts of methyl ethyl ketone were charged, and the temperature was raised to 60 ° C. Next, 22.6 parts of isophorone diisocyanate and 0.01 part of dibutyltin dilaurate were added, and the temperature was raised to 78 ° C. and reacted for 7 hours. The obtained urethane resin (b) had a weight average molecular weight of 12,400 and an acid value of 67 mgKOH / g. After the reaction, 4.0 parts of ammonia water having a concentration of 28% and 233.3 parts of ion-exchanged water were added to neutralize and remove the solvent. After removing the solvent, the non-volatile component was adjusted to 35.0% by weight with ion-exchanged water.

[Production Example 20]
While introducing nitrogen gas into a reaction vessel equipped with a stirrer, a thermometer, two dropping funnels and a refluxing vessel, 1333.3 parts of a 30.0 wt% aqueous solution of the urethane resin (b) obtained in Production Example 19 was added. The temperature was raised to 80 ° C. Next, two dropping funnels were prepared. On one side, 10.0 parts of ethyl acrylate, 55.0 parts of 2-ethylhexyl acrylate, and 35.0 parts of α-methylstyrene were added dropwise over 2 hours. From the other side, 6.5 parts of a 20% aqueous solution of ammonium persulfate was added dropwise over 2 hours. After completion of the dropwise addition, the reaction was terminated after continuing. The non-volatile content of the solution was adjusted to 35.0% by weight with ion exchange water to obtain an aqueous dispersion of urethane acrylic resin (UrAc1). The acid value of the obtained resin was 54 mgKOH / g. The acid value was measured by the method described above.

<Manufacture of printing ink (y)>
[Production Example 21]
20.0 parts of phthalocyanine blue (Lionol Blue FG-7400, manufactured by Toyocolor Co.), 60.0 parts of acrylic resin (A) (Em type acrylic resin (Ac11)), 17.5 parts of water, and ethanol 2.0 Parts were stirred and mixed, and pigment dispersion was carried out using a sand mill according to a conventional method to obtain a printing ink (y1).

[Production Examples 22 to 33]
In the configuration shown in Table 4, printing inks (y2 to y13) were obtained in the same manner as in Example 21. In Production Example 27, carbon black (REGAL 250R, manufactured by Cabot) was used as a pigment. In Production Examples 26 and 27, 3.0 parts of Carbodilite SV-02 (Nisshinbo Co., Ltd.) was added as a curing agent after pigment dispersion.

<Manufacture of printing ink (z)>
[Production Example 34]
80.0 parts of urethane resin B (Ur2), 18.0 parts of water, and 2.0 parts of ethanol were mixed by stirring to obtain a printing ink (z1).

[Production Example 35]
40.0 parts of acid value titanium (Taipeke CR80, manufactured by Ishihara Sangyo Co., Ltd.), 40.0 parts of urethane resin B (Ur2), 18.0 parts of water, and 2.0 parts of ethanol are stirred and mixed, and a sand mill is used. Then, pigment dispersion was performed according to a conventional method to obtain a printing ink (z2).

[Production Examples 36 to 44]
With the configuration shown in Table 5, printing inks (z3 to z11) were obtained in the same manner as in Example 34. In Production Example 39, 3.0 parts of Carbodilite SV-02 (Nisshinbo Co., Ltd.) was added as a curing agent after dispersing the pigment.

<Preparation of printing ink laminate (printing ink composition (I))>
[Example 1]
Using a central impression (CI) type flexographic printing machine on treated polypropylene (P2161, manufactured by Toyobo Co., Ltd.), printing speed (150m) in the order of printing ink (y1) and printing ink (z1) by anilox roll and resin plate. Printed at / min. A polyisocyanate-based adhesive “EA-N373A / EA-N373B” (manufactured by Toyo Morton Co., Ltd.) was applied to the printed matter, and a non-slave laminating machine was used at a line speed of 50 m / min to form a sealant CPP ( Nippon Polychem Co., Ltd.) was affixed and aged at 40 ° C. for 48 hours to obtain a printing ink construct (I-1).

[Examples 2 to 13] [Comparative Examples 1 to 6]
Using the printing ink (y) and the printing ink (z) shown in Table 6-1 and Table 6-2, printing ink constituents (I-2 to I-19) were obtained in the same manner as in Example 1.

<Preparation of printing ink laminate (printing ink composition (II))>
[Example 14]
Printing ink (z1) and printing ink (y1) are printed in this order on the treated polypropylene (P2161, Toyobo Co., Ltd.) by the same printing method as in Example 1 to obtain a printing ink structure (II-1). It was.

[Examples 15 to 26] [Comparative Examples 7 to 12]
Using the printing ink (y) and the printing ink (z) shown in Table 7-1 and Table 7-2, printing ink constituents (II-2 to II-19) were obtained in the same manner as in Example 14.

  Using the printing ink laminates (printing ink constituents (I-1 to I-19) and printing ink constituents (II-1 to II-19)), printing ink constituents (I-1 to I-19) Then, tape adhesion, scratch resistance, blocking resistance, and laminate suitability were evaluated. For printing ink constructions (II-1 to II-19), tape adhesion, scratch resistance, blocking resistance, and friction resistance were evaluated. , Resistance to water friction and resistance to rubs were evaluated.

<Tape adhesion>
A cellophane tape was affixed to the ink coating surface of the obtained printing ink laminate immediately after ink printing, and then peeled off strongly to visually determine the degree of ink peeling.
The practical level is ◯ or higher.
A: The ink did not peel at all. B: The ink slightly peeled from the film (less than 20%).
Δ: The ink peels from the film (20% or more, less than 50%)
X: The ink is remarkably peeled from the film (50% or more)

<Scratch resistance>
The ink-printed surface of the obtained printing ink laminate immediately after ink printing was scratched with a nail, and scratch resistance was evaluated from the degree of damage to the coating film.
The practical level is ◯ or higher.
◎: Scratch-free ○: Slightly scratched △: Scratched ×: Severely scratched (peeled even when the nail is vertical)

<Blocking resistance>
The obtained printing ink laminate immediately after ink printing is cut into a size of 4 cm × 4 cm, and this ink coated surface and treated polypropylene cut to the same size (P2161, manufactured by Toyobo Co., Ltd.) ) And a non-treated surface, and a load of 10 kg / cm ² is applied and left for 24 hours in an atmosphere of 40 ° C. and 80% RH. The blocking property was evaluated.
The practical level is ◯ or higher.
A: The ink did not peel at all. B: The ink slightly peeled off from the film (less than 10%).
Δ: Ink peels from film (10% or more, less than 50%)
X: The ink is remarkably peeled from the film (50% or more)

<Lamination suitability>
The ink part in the printing ink structure (I) was cut at a width of 15 mm and peeled between the ink surface and the sealant layer, and then the laminate strength was evaluated with an Intesco 201 universal tensile tester.
In addition, a practical use level is (circle) (1.0N / 15mm or more) or more.
A: Tensile strength of 1.5 N / 15 mm or more B: Tensile strength of 1.0 N / 15 mm or more and less than 1.5 N / 15 mm Δ: Tensile strength of 0.5 N / 15 mm or more, 1.0 N / 15 mm Less than x: Tensile strength less than 0.5N / 15mm

<Abrasion resistance>
About the obtained printing ink structure (II), the ink coating surface was rubbed 100 times with absorbent cotton, and then the degree of ink peeling was visually determined.
The practical level is ◯ or higher.
A: The ink did not peel at all. B: The ink slightly peeled off from the film (less than 10%).
Δ: Ink peels from film (10% or more, less than 50%)
X: The ink is remarkably peeled from the film (50% or more)

<Water friction resistance>
About the obtained printing ink structure (II), the ink coating surface was rubbed 20 times with water-containing absorbent cotton, and then the degree of ink peeling was visually determined.
The practical level is ◯ or higher.
A: The ink did not peel at all. B: The ink slightly peeled off from the film (less than 10%).
Δ: Ink peels from film (10% or more, less than 50%)
X: The ink is remarkably peeled from the film (50% or more)

<Scratch resistance>
The degree of ink peeling when the ink-coated surfaces of the obtained printing ink construction (II) were rubbed together was visually determined.
The practical level is ◯ or higher.
A: The ink did not peel at all even after rubbing 30 times or more. ○: The ink peeled slightly from the film when rubbing about 30 times (less than 20%).
Δ: The ink peels from the film when rubbed about 30 times (20% or more, less than 50%)
X: When the ink is rubbed about 30 times, the ink remarkably peels from the film (50% or more)

  The evaluation results are shown in Table 6-1, Table 6-2, Table 7-1 and Table 7-2. Printing ink lamination of Examples 1 to 26, in which an ink film layer (Y) containing an acrylic resin (A) and an ink film layer (Z) containing a urethane resin B are laminated in the normal or reverse order according to the printing configuration The body had better coating film properties (tape adhesion, scratch resistance, blocking resistance, suitability for lamination, friction resistance, water friction resistance, and rub resistance) than Comparative Examples 1-12. In particular, when an ink film layer (Y) containing an acrylic resin (A) and an ink film layer (Z) containing a polyurethane resin (B) having an acid value of 25 to 50 mgKOH / g are used in combination, the coating film properties (tape adhesion) Property, scratch resistance, blocking resistance, laminate suitability, rub resistance, water rub resistance, and rub resistance) were further improved.

Claims (3)

A printing ink structure (I) in which a plastic film (X) is laminated with a first ink film layer (Y), a second ink film layer (Z), and a sealant film in order through an adhesive. )
Or the printing ink structure (II) formed by laminating the second ink film layer (Z) and the first ink film layer (Y) in this order on the plastic film (X).
A printing ink laminate having the following (1) to (3).
(1) The first ink film layer (Y) contains an acrylic resin (A) having an acid value of 50 to 140 mgKOH / g, an organic pigment, and / or carbon black.
(2) The second ink film layer (Z) contains the polyurethane resin (B).
(3) The difference in acid value between the acrylic resin (A) and the polyurethane resin (B) is 90 mgKOH / g or less. The printing ink laminate according to claim 1, wherein the polyurethane resin (B) has an acid value of 25 to 50 mgKOH / g. The printed ink laminate according to claim 1 or 2, wherein the ink film layer (Y) and the ink film layer (Z) are formed by a flexographic printing method.