JP7035480B2 - A water-based liquid ink and a laminate using the water-based liquid ink - Google Patents

Description

The present invention relates to a water-based gravure ink for flexible packaging laminating, a water-based liquid ink for water-based flexographic ink, and a laminate using the water-based liquid ink.
In particular, the present invention relates to a water-based liquid ink having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths, and a laminate using the water-based liquid ink.
Further, the present invention also relates to a water-based liquid ink having excellent viscosity stability, adhesion to the substrate of the cured coating film, and various coating film strengths even in a system to which a curing agent is added, and a laminate using the water-based liquid ink. ..

Gravure inks and flexographic inks are widely used for the purpose of imparting beauty and functionality to the printed material of a flexible packaging film. When the gravure-printed or flexo-printed object is used as a flexible packaging material for foods and hygiene products among packaging materials, it is generally laminated. In this case, various printed materials and laminating processes are used depending on the type of contents and the purpose of use. By laminating the printed matter and various films with an adhesive, it is possible to maintain the film surface strength, storage stability, boil / retort suitability, etc., which cannot be obtained by the printed matter alone.
On the other hand, when laminating a printed matter, the printed matter itself is often intended to protect the contents. In this case, since the printed matter consisting of the base plastic, the printing ink layer, and the sealant film are laminated using an adhesive, the printing ink layer does not directly touch the contents, but the laminating suitability is required. .. Then, in order to maintain the laminating suitability, it is usually practiced to improve the adhesion between the plastic film of the base material and the printing ink layer by providing an anchor coat layer under the printing ink layer.

However, in response to recent efforts to conserve resources and simplify packaging, there is a demand to use gravure flexo printed matter itself as packaging material for the purpose of reducing the amount of film derived from petroleum resources and simplifying post-processing. Increasingly, the printing ink layer itself is required to have high coating film properties such as film adhesion, abrasion resistance, water resistance, and blocking resistance.
In addition, the superiority or inferiority of the print design in the flexible packaging film packaging material has a great influence on the quality of the contents, and high image reproducibility that can correspond to the advanced design conscious of cosmetics is required. ..

In recent years, from the perspective of sustainability against the backdrop of global expansion such as worsening air pollution due to VOCs and global warming, occupational safety and health, as well as flammability and explosiveness, have been added to the shift to de-oil resources. Therefore, it is expected to replace the organic solvent in the ink with water-based ink. For example, 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 coating material properties and ink physical properties that could not be obtained so far. However, since the combination structure of these ink film layers requires an overprint varnish layer using a volatile organic compound or an aqueous polyurethane anchor coat varnish layer, it can be said that the productivity at the time of printing is sufficient. No (for example, Patent Document 1).
Further, although an invention of a printing ink laminate using an acrylic resin or a polyurethane resin as a printing ink adjacent to a plastic film has been made, performance is required in applications such as a body-wrapped shrink label that requires film adhesion and water resistance. In terms of aspects, it cannot be said that it is sufficient (for example, Patent Document 2).
Further, when it is desired to add a curing agent to the water-based ink immediately before the printing work, the substrate of the cured coating film is maintained in a constant viscosity for at least 6 hours after the addition of the curing agent in consideration of the workability. It cannot be said that it will be easy to combine the adhesiveness and the strength of various coating films.

Japanese Unexamined Patent Publication No. 2005-225083 Japanese Unexamined Patent Publication No. 2016-155340

An object of the present invention is to provide a water-based liquid ink having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths, and a laminate using the water-based liquid ink.
Further, even in a system to which a curing agent is added, a water-based liquid ink having excellent viscosity stability, adhesion to the substrate of the cured coating film, and various coating film strengths, and a laminate using the water-based liquid ink can be obtained. To provide.

It has been found that the water-based liquid ink of the present invention is effective in solving a problem by using at least two kinds of acrylic resins having different acid values in a specific ratio.

That is, in the present invention, the solid content mass ratio of the (meth) acrylic resin (A1) having an acid value of less than 50 (mgKOH / g) and the (meth) acrylic resin (A2) having an acid value of 50 (mgKOH / g) or more is , (A1): (A2) = 69: 1 to 20:50. The present invention relates to a water-based liquid ink.

Furthermore, the present invention further relates to an aqueous liquid ink containing an epoxy compound.

Furthermore, the present invention relates to a water-based liquid ink containing a pigment.

Further, the present invention is a laminate having one or a plurality of printing layers on a plastic film, and at least one of the printing layers is a (meth) acrylic resin (A1) having an acid value of less than 50 (mgKOH / g). ) And the solid content mass ratio of the (meth) acrylic resin (A2) having an acid value of 50 (mgKOH / g) or more in the range of (A1) :( A2) = 69: 1 to 20:50. The present invention relates to a laminate having a print layer of liquid ink (A).

Further, in the present invention, the printing layer is a plurality of layers, the first printing layer formed of a printing ink containing a polyurethane resin or an acrylic polyurethane resin and a pigment on a plastic film, and the water-based liquid ink (A). The present invention relates to a laminate having a second printed layer formed by the above in this order.

Further, in the present invention, the printing layer is a plurality of layers, the first printing layer formed of a printing ink containing a polyurethane resin or an acrylic polyurethane resin and a pigment on a plastic film, and the aqueous solution containing a white pigment. The present invention relates to a laminate having a second white printing layer formed of the liquid ink (A) and a third printing layer formed of the water-based liquid ink (A) in this order.

The water-based liquid ink of the present invention is excellent in viscosity stability by using at least two kinds of acrylic resins having different acid values in a specific ratio, and also has the substrate adhesion of a cured coating film and various coating film strengths. It is possible to provide a liquid ink and a laminate using the water-based liquid ink.
Further, even in a system to which a curing agent is added, a water-based liquid ink having excellent viscosity stability, adhesion to the substrate of the cured coating film, and various coating film strengths, and a laminate using the water-based liquid ink can be obtained. Can be provided.

The present invention will be described in detail. The "inks" used in the following description all refer to "water-based liquid inks". Further, "parts" means all "parts by mass", and "%" means all "% by mass".

The aqueous liquid ink of the present invention has a solid content of a (meth) acrylic resin (A1) having an acid value of less than 50 (mgKOH / g) and a (meth) acrylic resin (A2) having an acid value of 50 (mgKOH / g) or more. It is essential that the mass ratio is contained in the range of (A1) :( A2) = 69: 1 to 20:50.
The acid value of the (meth) acrylic resin indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin, and each dried water-soluble resin is referred to as JIS K2501. It was calculated from the potentiometric titration with a potassium hydroxide / ethanol solution according to the above.

The (meth) acrylic resin (A1) and (A2) can be obtained by copolymerizing various (meth) acrylate monomers with other polymerizable unsaturated group-containing compounds, if necessary.
The monomer constituting the (meth) acrylic resin is not particularly limited, and is, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-butyl (meth) acrylate, iso-butyl (meth) acrylate, and tert-butyl (meth). ) Acrylate, 2-ethylhexyl (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, nonyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, isobornyl (meth) ) Acrylate, dicyclopentanyl (meth) acrylate, phenyl (meth) acrylate, benzyl (meth) acrylate, 2,2,2-trifluoroethyl (meth) acrylate, 2,2,3,3-pentafluoropropyl ( Meta) acrylate, perfluorocyclohexyl (meth) acrylate, glycidyl (meth) acrylate, allyl glycidyl ether, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, polyethylene glycol mono (meth) acrylate, (meth) ) Acrylate, N-monoalkyl (meth) acrylamide, N, N-dialkyl (meth) acrylamide, N-methylol (meth) acrylamide, N-isopropoxymethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N -(Meta) acrylic monomers such as isobutoxymethyl (meth) acrylamide, 2-aziridinyl ethyl (meth) acrylate, dicyclopentenyl (meth) acrylate, achlorine, diacetone (meth) acrylamide, and acetoacetoxyethyl (meth) acrylate. Can be used.
The "(meth) acrylate" refers to either or both of acrylate and methacrylate, and "(meth) acrylic" refers to either or both of acrylic and methacrylic.

Examples of the polymerizable unsaturated group-containing compound include vinyl acetate, vinyl propionate, vinyl versatic acid, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, (meth) acrylonitrile, and styrene, in addition to the (meth) acrylic monomer. , Α-Methylstyrene, divinylstyrene, isoprene, chloroprene, butadiene, ethylene, tetrafluoroethylene, vinylidene fluoride, N-vinylpyrrolidone and other vinyl monomers can also be used.
These may be used alone or in combination of two or more.

Further, the acrylic resins (A1) and (A2) having an acid value introduce one or more hydrophilic groups selected from the group consisting of a carboxyl group and a carboxylate group in which the carboxyl group is neutralized with a basic compound. It has a carboxyl group such as (meth) acrylic acid, crotonic acid, itaconic acid, maleic acid, fumaric acid, β- (meth) acryloyloxyethyl hydrogen succinate, and β- (meth) acryloyloxyethyl hydrogen phthalate. It can be obtained by copolymerizing a (meth) acrylic monomer.

The acrylic resins (A1) and (A2) can be produced, for example, by polymerizing various monomers in a temperature range of 60 ° C to 150 ° C in the presence of a polymerization initiator. Examples of the polymerization method include a bulk polymerization method, a solution polymerization method, a suspension polymerization method, an emulsification polymerization method and the like. In addition, examples of the polymerization mode include random copolymers, block copolymers, graft copolymers, and the like.

[Core shell type resin]
In the present invention, it is preferable to use a core-shell type resin for the (meth) acrylic resin (A1) having an acid value of less than 50 (mgKOH / g).
The core-shell type resin used in the present invention refers to a state in which the polymer (a2) is dispersed in an aqueous medium by the polymer (a1), and the polymer (a1) is usually present on the outermost side of the resin particles. In many cases, a shell portion is formed of the polymer (a2), and a part or all of the polymer (a2) forms a core portion. Hereinafter, in the present invention, the resin forming the shell portion will be referred to as a polymer (a1), and the resin forming the core portion will be referred to as a polymer (a2).

[Polymer constituting the shell portion (a1)]
The core-shell type resin used in the present invention is one or more hydrophilic groups selected from the group consisting of a carboxyl group and a carboxylate group formed by neutralizing the carboxyl group of the polymer (a1) constituting the shell portion. It is preferable that it is composed of one containing an acrylic resin having. At that time, the acid value of the shell portion is preferably in the range of 40 or more and 250 or less, and more preferably 120 or less.

It is preferable that the carboxyl group of the polymer (a1) constituting the shell portion is neutralized with a basic compound to form a carboxylate group.

As the basic compound that can be used for neutralization, for example, ammonia, triethylamine, morpholine, monoethanolamine, diethylethanolamine and the like can be used, and the use of ammonia and triethylamine can be used to withstand the temperature of the coating film. It is preferable for further improving the property, corrosion resistance and chemical resistance.

The amount of the basic compound used is [basic compound / carboxyl group] with respect to the total amount of the carboxyl group of the polymer (a1) in order to further improve the water dispersion stability of the obtained core-shell type resin. It is preferable to use it in the range of = 0.2 to 2 (molar ratio).

Among the monomers having a polymerizable unsaturated double bond, it is preferable to use a monomer obtained by polymerizing a (meth) acrylic monomer containing a (meth) acrylic monomer having a carboxyl group. In particular, as the polymer (a1), methyl (meth) acrylate, butyl (meth) acrylate, in order to adjust the glass transition temperature (Tg1) of the polymer (a1) to the range of 30 ° C. to 100 ° C., It is more preferable to use a polymer obtained by combining and polymerizing (meth) acrylic acid or the like in order to form a coating film having excellent film-forming property and excellent temperature water resistance, corrosion resistance and chemical resistance.

[Polymer constituting the core portion (a2)]
As the polymer (a2) constituting the core portion, a copolymer such as an acrylic monomer similar to the above-mentioned acrylic resin can be used.
At this time, the weight average molecular weight of the core portion is preferably in the range of 200,000 to 3,000,000, and more preferably 800,000 or more. Tg is preferably in the range of −30 ° C. to 30 ° C.

As the polymer (a2) constituting the core portion, a copolymer such as an acrylic monomer similar to the above-mentioned acrylic resin can be used, but among them, it is preferably produced in an aqueous medium. Specifically, the monomer and the polymerization initiator and the like can be produced by collectively supplying or sequentially supplying them to a reaction vessel containing an aqueous medium for polymerization. At that time, a pre-emulsion is produced by previously mixing the monomer, an aqueous medium, and a reactive surfactant or the like, if necessary, and the polymerization initiator or the like is supplied to a reaction vessel containing the aqueous medium. It may be polymerized.

Examples of the polymerization initiator that can be used in producing the polymer (a2) include radical polymerization initiators such as persulfates, organic peroxides, and hydrogen peroxide, and 4,4'-azobis (4-4'-azobis). An azo initiator such as cyanovaleric acid), 2,2'-azobis (2-amidinopropane) dihydrochloride can be used. Further, the radical polymerization initiator may be used as a redox polymerization initiator in combination with a reducing agent described later.

As the persulfate, for example, potassium persulfate, sodium persulfate, ammonium persulfate and the like can be used. Examples of the organic peroxide include benzoyl peroxide, lauroyl peroxide, decanoyle peroxide, t-butyl cumyl peroxide, dicumyl peroxide, t-butyl peroxylaurate, and t-butyl peroxybenzoate. , Kumen hydroperoxide, paramentan hydroperoxide, t-butyl hydroperoxide and the like can be used.

Examples of the reducing agent include ascorbic acid and its salt, erythorbic acid and its salt (sodium salt, etc.), tartrate acid and its salt, citric acid and its salt, formaldehyde sulfoxylate metal salt, sodium thiosulfate, and the like. Sodium disulfide, ferric chloride, etc. can be used.

The amount of the polymerization initiator used may be an amount that allows the polymerization to proceed smoothly, but it is preferable that the amount is small from the viewpoint of maintaining the excellent corrosion resistance of the obtained coating film, and it is preferable for the production of the vinyl polymer (a2). It is preferably 0.01% by mass to 0.5% by mass with respect to the total amount of the monomers used. Further, when the polymerization initiator is used in combination with the reducing agent, it is preferable that the total amount of the polymerization initiators used is also within the above range.

In addition, when producing the pre-emulsion, a reactive surfactant, anionic surfactant, nonionic surfactant, cationic surfactant, amphoteric ionic surfactant and the like are used. May be good.

By containing the acrylic resin (A) in two types, a (meth) acrylic resin (A1) having an acid value of less than 50 and a (meth) acrylic resin (A2) having an acid value of 50 or more, only the acrylic resin (A1) can be used. While it is possible to maintain the substrate adhesion, heat resistance, and viscosity stability of the printing ink that cannot be compensated for, the friction resistance, water friction resistance, and scratch resistance that cannot be compensated by acrylic resin (A2) alone tend to be good. The laminate using a mixture of both in a specific ratio is water-based, which has basic coating strength such as substrate adhesion, abrasion resistance, water abrasion resistance, scratch resistance, and heat resistance, as well as viscosity stability. A liquid printing ink laminate can be provided.

The ratio of the (meth) acrylic resin (A1) having an acid value of less than 50 to the (meth) acrylic resin (A2) having an acid value of 50 or more is the mass ratio of the solid content (A1) :( A2) = 69: 1. The range is preferably from 20:50, more preferably from 39: 1 to 10:30, and even more preferably from 35: 1 to 1: 1.

The (meth) acrylic resin (A1) having an acid value of less than 50 is preferably an acid value of 10 or more and less than 50. If the acid value is less than 50, it is possible to suppress deterioration of scratch resistance, water resistance, and heat resistance.
The (meth) acrylic resin (A2) having an acid value of 50 or more is preferably an acid value of 50 or more and 250 or less, and more preferably an acid value of 100 or more. When the acid value is 100 mgKOH / g or more, it is possible to improve the substrate adhesion, scratch resistance, and coating film strength of the laminated body when a curing agent is added.
The acid value referred to here indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin.

The weight average molecular weight of the (meth) acrylic resin (A1) is preferably in the range of 400,000 to 3,000,000. When the weight average molecular weight is 400,000 or more, the heat resistance of the resin film does not deteriorate, and the friction resistance and the water friction resistance of the laminate tend to be maintained. If it is 3,000,000 or less, the laminate tends to have both substrate adhesion and scratch resistance.
The weight average molecular weight of the (meth) acrylic resin (A2) is preferably in the range of 10,000 to 100,000. When the weight average molecular weight is 10,000 or more, the strength of the resin film does not decrease, and the substrate adhesion, heat resistance, and viscosity stability of the laminate tend to be maintained. If it is 100,000 or less, the laminate tends to have both substrate adhesion and scratch resistance.

The glass transition temperature (Tg) of the (meth) acrylic resin (A1) is preferably in the range of −30 ° C. to 30 ° C. When the Tg of the (meth) acrylic resin (A) is -30 ° C or higher, the film strength is maintained, the water friction resistance of the laminate does not decrease, and when the Tg is 30 ° C or lower, it is different from other printing layers. There is a tendency that the friction resistance, the water friction resistance, and the scratch resistance of the laminated body are kept good without deteriorating the compatibility of the laminated body.
The glass transition temperature (Tg) of the (meth) acrylic resin (A2) is preferably in the range of 40 ° C to 100 ° C. When the Tg of the (meth) acrylic resin (A) is 40 ° C. or higher, the film strength of the resin is maintained, the friction resistance and water friction resistance of the laminate do not decrease, and conversely, the temperature is 100 ° C. or lower. For example, the film forming property of the resin is improved, the scratch resistance is not deteriorated, and the substrate adhesion of the laminated body tends to be kept good.
The glass transition temperature (Tg1) refers to a so-called calculated glass transition temperature, and refers to a value calculated by the following method.
(Equation 1) 1 / Tg (K) = (W1 / T1) + (W2 / T2) + ... (Wn / Tn)
(Equation 2) Tg (° C.) = Tg (K) -273
W1, W2, ... Wn in the formula 1 represent the mass% of each monomer with respect to the total mass of the monomers used for producing the polymer, and T1, T2, ... Tn are homopolymers of each monomer. Represents the glass transition temperature (K). As the values of T1, T2, ... Tn, the values described in Polymer Handbook (Fourth Edition, J. Brandrup, E.H. Immunogut, EA Grulke) are used.
Although the glass transition temperature of the homopolymer of each monomer is not described in the Polymer Hand Book, the glass transition temperature is based on JIS K7121 using a differential scanning calorimeter "DSC Q-100" (manufactured by TA Instrument). It was measured by the method described above. Specifically, the polymer from which the solvent has been completely removed by vacuum suction is measured for a change in calorific value in the range of -100 ° C to + 200 ° C at a heating rate of 20 ° C / min, and an extended straight line of each baseline. The point where the straight line at the same distance in the vertical axis direction and the curve of the stepwise change portion of the glass transition intersect was defined as the glass transition temperature.

Further, in the water-based liquid ink of the present invention, an epoxy compound can be further added.
Examples of the epoxy compound include phenol (EO) ₅ glycidyl ether (CAS number: 54140-67-9), lauryl alcohol (EO) ₁₅ glycidyl ether (CAS number: 86630-59-3), and glycerol polyglycidyl ether. Diglycerol polyglycidyl ether, polyglycerol polyglycidyl ether, sorbitol polyglycidyl ether, ethylene glycol diglycidyl ether, diethylene glycol diglycidyl ether, polyethylene glycol diglycidyl ether, propylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, epoxy cresol novolac, etc. These have an effect as a curing agent.

Of these, sorbitol polyglycidyl ether is more preferable.
Aliphatic polyfunctional epoxy compounds using sorbitol as a parent skeleton have high reactivity derived from a high functional number, and after curing, they have a high crosslink density while being aliphatic, and a cured film with a solid crosslinked structure. It leads to an increase in strength.
The (meth) acrylic resin (A1) having an acid value of less than 50 (mgKOH / g) and the (meth) acrylic resin (A2) having an acid value of 50 (mgKOH / g) or more are used as the (meth) acrylic resin (A1). ): By further adding an epoxy compound to the composition containing the (meth) acrylic resin (A2) in the range of 69: 1 to 20:50, the curing speed is increased and the viscosity stability is slightly lowered. , The base material adhesion, wear resistance, water friction resistance, scratch resistance, heat resistance, etc. of the ink layer to the film base material can be further strengthened.
The amount of the epoxy compound added is preferably 0.1 to 10.0% by mass, more preferably 0.5 to 9.0% by mass in terms of the solid content of the total amount of the ink.
If the addition amount is 0.1% by mass or more, the effect as a curing agent can be obtained, while if it is 10.0% by mass or less, the substrate adhesion, friction resistance, and water friction resistance tend to be maintained. Become.

Further, the water-based liquid ink of the present invention can be added with a pigment. The pigment may be either a colored pigment or a white pigment. If a white pigment is added, it can also be used as a white ink corresponding to the background of a pattern, for example, for example, front printing and gravure printing. If these pigments are not added, it can also be used as an overcoat varnish.

Examples of the coloring pigment used in the water-based liquid ink of the present invention include organic pigments and dyes used in general inks, paints, recording agents and the like. Organic pigments include azo-based, phthalocyanine-based, anthraquinone-based, perylene-based, perinone-based, quinacridone-based, thioindigo-based, dioxazine-based, isoindoleinone-based, quinophthalone-based, azomethine-azo-based, dictopyrrolopyrrole-based, and isoindoline-based. Pigments can be mentioned.

As a color index name,
C. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 42, 74, 83;
C. I. Pigment Orange 16;
C. I. Pigment Red 5, 22, 38, 48: 1, 48: 2, 48: 4, 49: 1, 53: 1, 57: 1, 63: 1, 81, 101;
C. I. Pigment Violet 19, 23;
C. I. Pigment Blue 23, 15: 1, 15: 3, 15: 4, 17: 1, 18, 27, 29
C. I. Pigment Green 7, 36, 58, 59;
C. I. Pigment Black 7;
C. I. Pigment White 4, 6, 18 and the like.

For indigo ink, C.I. I. Pigment Blue 15: 3 (copper phthalocyanine), yellow ink is C.I. from the viewpoint of cost and light resistance. I. Pigment Yellow83, C.I. for red ink. I. It is preferable to use Pigment Red 57: 1. It is preferable to use carbon black for black ink, aluminum for gold and silver ink, and mica (mica) for pearl ink from the viewpoint of cost and coloring power. Although aluminum is in the form of powder or paste, it is preferably used in the form of paste from the viewpoint of handleability and safety, and whether reefing or non-reefing is used is appropriately selected from the viewpoint of luminance and concentration.

Examples of the white pigment used in the water-based liquid ink of the present invention include titanium oxide, zinc sulfide, lead white, zinc flower, lithobon, antimony white, basic lead sulfate, basic lead silicate, and barium sulfate. Examples include calcium carbonate, gypsum, silica, and the like.
The average particle size of the pigment is preferably in the range of 10 to 200 nm, more preferably about 50 to 150 nm.
The amount of the coloring pigment added is preferably in the range of 1 to 20% by mass of the total amount of the ink in order to obtain a sufficient image density and light resistance of the printed image.

The water-based liquid ink of the present invention is a laminate having one or more printing layers on a plastic film, and at least one of the printing layers is a (meth) acrylic resin having an acid value of less than 50 (mgKOH / g). The solid content mass ratio of (A1) and the (meth) acrylic resin (A2) having an acid value of 50 (mgKOH / g) or more is contained in the range of (A1) :( A2) = 69: 1 to 20:50. It is possible to produce a laminate characterized by being a printing layer of the water-based liquid ink (A).

The plastic film as the base material used for the laminate is not particularly limited, and is, for example, a polyamide resin such as nylon 6, nylon 66, or nylon 46, polyethylene phthalate (PET), polyethylene naphthalate, or polytrimethylene terephthalate. , Polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate and other polyester resins, polylactic acid and other polyhydroxycarboxylic acids, poly (ethylene succinate), poly (butylene succinate) and other aliphatic polyester resins. Examples thereof include films made of biodegradable resins typified by biodegradable resins, polyolefin resins such as polypropylene (PP) and polyethylene, polyimide resins, polyarylate resins or thermoplastic resins such as mixtures thereof, and laminates thereof. A film made of polyester, polyamide, polyethylene or polypropylene can be preferably used.
These films may be unstretched films or stretched films, and the production method thereof is not limited. Further, the thickness of the base film is not particularly limited, but usually it may be in the range of 1 to 500 μm.
Further, if the printed surface of the film is subjected to a corona discharge treatment, the adhesion to the substrate can be further improved, which is preferable. Further, silica, alumina and the like may be vapor-deposited.

When the laminated body has a plurality of layers, if the printing layer of the water-based liquid ink (A) is provided on the uppermost layer farthest from the plastic film as the base material, the strength of the laminated body becomes more sufficient and the base material. The basic coating film strength such as adhesion, friction resistance, water friction resistance, scratch resistance, and heat resistance tends to be more maintained. It is especially useful for overcoat varnish applications. Of course, as described above, a coloring pigment or a white pigment may be added to the water-based liquid ink (A), or if the water-based liquid ink (A) is printed and laminated over a plurality of layers, a stronger laminate is formed. Tends to be obtained.
Further, in the laminated body in which the epoxy compound is further added in an appropriate amount to the water-based liquid ink (A), the viscosity stability is slightly lowered due to the increase in the curing speed, but the substrate adhesion, abrasion resistance, water friction resistance, and water resistance resistance. It is possible to obtain a tougher laminate that has both scratch resistance and heat resistance.

Further, in the laminate using the water-based liquid ink of the present invention, the printing layer is a plurality of layers, and the first printing layer formed by the printing ink containing a polyurethane resin or an acrylic polyurethane resin and a pigment on a plastic film. And a second white printing layer formed by the water-based liquid ink (A) containing a white pigment can be produced in this order.

By using the polyurethane resin or acrylic polyurethane resin for the first printing layer, the coating film is more flexible than the acrylic resin, has high adhesion to the plastic film, and has high followability due to deformation of the film base material. .. In addition, the polyurethane resin or acrylic polyurethane resin has the same or better performance as the acrylic resin in terms of pigment dispersibility, resolubility during printing, and color development when the pigment is dispersed, and is compatible with the pigment. ..
In addition, when acrylic polyurethane resin is used, color development and resolubility are better than when polyurethane resin is used, and thread pulling during printing occurs compared to a coating film made of flexible and tough polyurethane resin. It tends to be difficult to do. Both the polyurethane resin and the acrylic polyurethane resin may be mixed and used, or the acrylic resin may be appropriately mixed and used as needed.

The acid value of the polyurethane resin is preferably in the range of 10 to 50 mgKOH / g. When the acid value is 10 mgKOH / g or more, the resolubility of the ink film in water-based solvent in printing deteriorates, and the tone reproducibility of the printed matter does not deteriorate, and the image reproduction when the liquid printing ink laminate is formed is reproduced. It is also possible to suppress the deterioration of sex.
On the contrary, when the acid value is 50 mgKOH / g or less, the water resistance of the resin does not decrease, and the deterioration of the substrate adhesion and the water friction resistance of the laminate can be suppressed. The acid value referred to here indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin.

The acrylic polyurethane resin preferably has a weight average molecular weight of 20,000 to 2,000,000 and an acid value of 10 to 60 mgKOH / g, and more preferably has a weight average molecular weight of 30,000 to 1,500,000. , 20-50 mgKOH / g. If the weight average molecular weight is 20,000 or more, the friction resistance and the water friction resistance do not decrease, and if the weight average molecular weight is 2,000,000 or less, the deterioration of the substrate adhesion is suppressed. Can be done.
Further, when the acid value is 10 mgKOH / g or more, the tone reproducibility of the printed matter does not deteriorate, and the image reproducibility as a liquid printing ink laminate can be well maintained.
On the other hand, when the acid value is 60 mgKOH / g or less, the water resistance of the resin does not decrease, and the substrate adhesion and the water friction resistance of the laminate can be kept good.

Further, in the present invention, the printing layer is a plurality of layers, the first printing layer formed of a printing ink containing a polyurethane resin or an acrylic polyurethane resin and a pigment on a plastic film, and the aqueous liquid containing a white pigment. The laminate according to claim 4, which has a second white printing layer formed of the ink (A) and a third printing layer formed of the water-based liquid ink (A) in this order, is also produced. Can be done.
The first printing layer formed of a printing ink containing a polyurethane resin or an acrylic polyurethane resin and a pigment on a plastic film can form a pattern with a coloring pigment according to the above, and the aqueous liquid containing a white pigment. The second white printing layer formed by the ink (A) can be used as a background of a pattern, for example, in front printing gravure printing. Further, the third printing layer formed from the water-based liquid ink (A) can be used for overcoat varnishing, and in some cases, a white pigment may be added.

The content of the resin contained in the aqueous liquid ink of the present invention is preferably 5 to 50% by mass in terms of solid content. When it is 5% by mass or more, the strength of the ink coating film does not decrease, and the adhesion to the substrate, the water friction resistance, and the like are kept good. On the contrary, when it is 50% by mass or less, the decrease in coloring power can be suppressed, the high viscosity can be avoided, and the workability does not decrease.

Regarding the water-based liquid ink of the present invention, the combined resin, extender pigment, pigment dispersant, leveling agent, defoaming agent, waxes, plasticizer, infrared absorber, ultraviolet absorber, fragrance, flame retardant, etc. Can also be included. Among them, fatty acid amides such as paraffin wax, polyethylene wax, carnauba wax, oleic acid amide, stearic acid amide, and erucic acid amide for imparting abrasion resistance, slipperiness, etc., and for suppressing foaming during printing. Silicon-based, non-silicon-based defoaming agents, various dispersants that improve the wetting of pigments, and the like are useful.

As the solvent contained in the water-based liquid ink of the present invention, water alone or an organic solvent miscible with water can be used. Examples of the organic solvent include alcohols such as methyl alcohol, ethyl alcohol, isopropyl alcohol and n-propyl alcohol, polyhydric alcohols such as propylene glycol and glycerin, propylene glycol monomethyl ether, propylene glycol monoethyl ether and propylene glycol mono n. -Ethers such as propyl ether and ethyl carbitol can be mentioned.

In the water-based liquid ink of the present invention, a pigment, water, or a mixture to which an organic solvent, a dispersant, a defoaming agent, etc. to be mixed with water is added is first dispersed by a disperser to obtain a pigment dispersion. It is obtained by adding a resin, water, or an organic solvent miscible with water, and if necessary, additives such as wax and a leveling agent to the obtained pigment dispersion, and stirring and mixing. As the disperser, it is manufactured by using a bead mill, an Eiger mill, a sand mill, a gamma mill, an attritor, etc., which are generally used for manufacturing gravure and flexographic printing inks.

When the water-based liquid ink of the present invention is used as a flexographic ink, its viscosity may be 7 to 25 seconds at 25 ° C. using Zahn Cup # 4 manufactured by Rigo Co., Ltd., more preferably 10 to 20 seconds. .. The surface tension of the obtained flexographic ink at 25 ° C. is preferably 25 to 50 mN / m, more preferably 33 to 43 mN / m. The lower the surface tension of the ink, the better the wettability of the ink to the substrate such as a film. Tend to be easily connected, which tends to cause stains on the printed surface called a dot bridge. On the other hand, when the surface tension exceeds 50 mN / m, the wettability of the ink on a substrate such as a film is lowered, which tends to cause repelling.

On the other hand, when the water-based liquid ink of the present invention is used as a gravure ink, its viscosity may be 7 to 25 seconds at 25 ° C. using Zahn Cup # 3 manufactured by Rigo Co., Ltd., more preferably 10 to 20 seconds. Is. The surface tension of the obtained gravure ink at 25 ° C. is preferably 25 to 50 mN / m, more preferably 33 to 43 mN / m, as in the flexographic ink. The lower the surface tension of the ink, the better the wettability of the ink to the substrate such as a film. Tend to be easily connected, which tends to cause stains on the printed surface called a dot bridge. On the other hand, when the surface tension exceeds 50 mN / m, the wettability of the ink on a substrate such as a film is lowered, which tends to cause repelling.

Hereinafter, the present invention will be described in more detail with reference to Examples. In the examples, "part" represents "parts by mass" and "%" represents "% by mass".
The weight average molecular weight (in terms of polystyrene) was measured by GPC (gel permeation chromatography) in the present invention using the HLC8220 system manufactured by Tosoh Corporation under the following conditions.
Separation column: Uses 4 TSKgelGMH _HR -N manufactured by Tosoh Corporation. Column temperature: 40 ° C. Moving layer: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow velocity: 1.0 ml / min. Sample concentration: 1.0% by mass. Sample injection volume: 100 microliters. Detector: Differential refractometer.
The acid value of the acrylic resin indicates the number of milligrams of potassium hydroxide required to neutralize the acidic component contained in 1 g of the resin, and each dried water-soluble resin is according to JIS K2501. It was calculated from the potentiometric titration with a potassium hydroxide / ethanol solution.
Further, the glass transition temperature (Tg) refers to a so-called calculated glass transition temperature, and refers to a value calculated by the following method.
(Equation 1) 1 / Tg (K) = (W1 / T1) + (W2 / T2) + ... (Wn / Tn)
(Equation 2) Tg (° C.) = Tg (K) -273
W1, W2, ... Wn in the formula 1 represent the mass% of each monomer with respect to the total mass of the monomers used for producing the polymer, and T1, T2, ... Tn are homopolymers of each monomer. Represents the glass transition temperature (K). As the values of T1, T2, ... Tn, the values described in Polymer Handbook (Fourth Edition, J. Brandrup, E.H. Immunogut, EA Grulke) are used.
Although the glass transition temperature of the homopolymer of each monomer is not described in the Polymer Hand Book, the glass transition temperature is based on JIS K7121 using a differential scanning calorimeter "DSC Q-100" (manufactured by TA Instrument). It was measured by the method described above. Specifically, the polymer from which the solvent has been completely removed by vacuum suction is measured for a change in calorific value in the range of -100 ° C to + 200 ° C at a heating rate of 20 ° C / min, and an extended straight line of each baseline. The point where the straight line at the same distance in the vertical axis direction and the curve of the stepwise change portion of the glass transition intersect was defined as the glass transition temperature.

[Synthesis Example 1: Preparation of Shell Acrylic Resin (Polymer a1)]
The reaction vessel is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 60.0 parts of n-propyl acetate is charged. The temperature was raised to 90 ° C. while stirring in a nitrogen atmosphere. On the other hand, 36.0 parts of methyl acrylate, 10.0 parts of n-butyl acrylate, 20.0 parts of n-butyl methacrylate, 20.0 parts of 2-ethylhexyl acrylate, 14.0 parts of acrylic acid, 1 part of azobisisobutyronitrile. .2 parts were dissolved in 40.0 parts of n-propyl acetate and added dropwise over 4 hours using a dropping funnel. After the completion of the dropping, the reaction was carried out for another 6 hours. After completion of the reaction, the mixture was cooled and neutralized by adding 8.0 parts of 30% aqueous ammonia to the obtained acrylic resin solution. Further, ion-exchanged water was added and solvent substitution was performed while heating to obtain an aqueous solution of an acrylic resin having a solid content of 55%. The acid value was 105 mgKOH / g, Tg was 65 ° C., and the weight average molecular weight was 18,000.

[Synthesis Example 2: Preparation of Core-Shell Acrylic Emulsion (A1)] Acid Value 42
A stirrer, a thermometer, a dropping funnel, and a reflux tube are provided in a reaction vessel containing 121.2 parts of the acrylic resin aqueous solution prepared in Synthesis Example 1, and 195.5 parts of ion-exchanged water is added. The temperature was raised to 75 ° C. while stirring in a nitrogen atmosphere. Subsequently, using a dropping funnel, 30.0 parts of methyl methacrylate, 25.0 parts of n-butyl acrylate, 45 parts of 2-ethylhexyl acrylate, and 3.3 parts of 30% ammonium persulfate were added dropwise over 4 hours. After the dropping was completed, the reaction was further carried out for 6 hours to obtain a core-shell type acrylic emulsion aqueous solution having a solid content of 40%. The acid value was 42 mgKOH / g, Tg was −20 ° C., and the weight average molecular weight was 1,200,000.

[Synthesis Example 3: Preparation of High Acid Value Acrylic Polymer (A2)] Acid Value 220
The reaction vessel is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 65.0 parts of n-propyl acetate is charged. The temperature was raised to 90 ° C. while stirring in a nitrogen atmosphere. On the other hand, 50.0 parts of styrene, 15.0 parts of 2-ethylhexyl acrylate, 35.0 parts of acrylic acid, and 2.5 parts of azobisisobutyronitrile were dissolved in 35.0 parts of n-propyl acetate, and a dropping funnel was added. It was added dropwise over 4 hours. After the completion of the dropping, the reaction was carried out for another 6 hours. After completion of the reaction, the mixture was cooled and neutralized by adding 20.0 parts of 30% aqueous ammonia to the obtained acrylic resin solution. Further, ion-exchanged water was added and solvent substitution was performed while heating to obtain an aqueous solution of an acrylic resin having a solid content of 30%. The acid value was 220 mgKOH / g, Tg was 60 ° C., and the weight average molecular weight was 10,000.

[Synthesis Example 4: Preparation of Polyurethane Resin Solution (Pu)]
186.9 parts of PLACCEL 212 (polycaprolactone diol manufactured by Daicel Chemical Industry Co., Ltd., hydroxyl value 90 mgKOH / g) and 100.0 parts of IPDI were charged. While stirring this, it was heated to 110 ° C. After 1 hour, the mixture was cooled to 80 ° C., 20.1 parts of DMPA, 0.3 part of dibutyltin dilaurate and 76.8 parts of ethyl acetate were added, and the mixture was reacted at 80 ° C. for 2 hours. To this, 18.1 part of Barnock DN-980S (manufactured by DIC, hexamethylene diisocyanate polyisocyanate, NCO content 20%) and 408 parts of MEK were added. The NCO group content at this time was 4.9% in terms of solid content.
This was cooled to 30 ° C. or lower, 15.2 parts of triethylamine was added, and then 1293 parts of ion-exchanged water was added to obtain an O / W type emulsion. Subsequently, 234 parts of a 5% aqueous solution of diethylenetriamine was gradually added, and after the addition was completed, the temperature was raised to 60 ° C. and stirring was continued for 30 minutes.
Then, distillation was carried out under reduced pressure to remove a part of the solvent and water.
This is a translucent liquid with a slightly milky white color, and when a small amount was taken in a test tube and THF was added, it became turbid and cross-linked to be insoluble. The non-volatile content was 39.6%, the viscosity was 160 cps, the pH was 7.7, and the average particle size was 28.5 nm.

[Adjustment example Au: Preparation of acrylic polyurethane (Au) resin solution]
The reaction vessel is equipped with a stirrer, a thermometer, a dropping funnel, and a reflux tube, and 80.0 parts of n-propyl acetate is charged. The temperature was raised to 90 ° C. while stirring in a nitrogen atmosphere. On the other hand, 32.0 parts of styrene, 20.0 parts of 2-hydroxyethyl methacrylate, 40 parts of 2-ethylhexyl acrylate, 8.0 parts of acrylic acid, 3.0 parts of azobisisobutyronitrile were added to n-propyl acetate 40. It was dissolved in 0 part and dropped over 4 hours using a dropping funnel. After completion of the dropping, 1.6 parts of Barnock DN-980S (manufactured by DIC, hexamethylene diisocyanate polyisocyanate, NCO content 20%) was gradually added, and the mixture was further reacted for 6 hours. After completion of the reaction, the mixture was cooled and neutralized by adding 4.0 parts of 30% aqueous ammonia to the obtained acrylic resin solution. Further, ion-exchanged water was added and solvent substitution was performed while heating to obtain an aqueous solution of an acrylic resin having a solid content of 25%. The acid value was 48 mgKOH / g, Tg was 54 ° C., and the weight average molecular weight was 600,000.

[Adjustment example 1: Manufacture of acrylic varnish]
Acrylic emulsion (A1) solid content 10 parts prepared in Synthesis Example 2, high acid value acrylic polymer (A2) solid content 25 parts prepared in Synthesis Example 3, polyethylene wax 5 parts, normal propanol 4 parts, defoaming agent 0. After stirring and mixing 1 part, 1.2 parts of aqueous ammonia and 54.7 parts of water, the mixture was kneaded with a bead mill to prepare an acrylic varnish. It was confirmed that the viscosity of the obtained acrylic varnish was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha).

[Adjustment Examples 2 to 10: Production of Acrylic Varnish]
Adjustment Examples 2 to 8 have the same composition as that of Adjustment Example 1 and the same procedure as that of Adjustment Example 1 except that the addition amounts of the acrylic emulsion (A1) and the high acid value acrylic polymer (A2) shown in Table 1 are changed. A varnish was made.
In Adjustment Example 9, only 35 parts of the acrylic emulsion (A1) solid content was used, and the high acid value acrylic polymer (A2) was not used.
In Adjustment Example 10, only 35 parts of the high acid value acrylic polymer (A2) was used, and the acrylic emulsion (A1) was not used.
It was confirmed that the viscosity of the obtained acrylic varnish was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha).

[Adjustment Examples 11 to 22: Production of Acrylic Varnish Containing Epoxy Hardener]
As shown in Table 2, 5 parts of the epoxy curing agent sorbitol polyglycidyl ether (Denacol EX-612 manufactured by Nagase ChemteX Corporation) was further added to the formulations of Adjustment Examples 1 to 8 and acrylic-based according to the same procedure. A varnish was made.
For adjustment examples 19 to 22, the amount of the epoxy curing agent sorbitol polyglycidyl ether (Denacol EX-612 manufactured by Nagase ChemteX Corporation) was changed according to the formulation in Table 3, and the total amount of ink was adjusted by the amount of water added. Was adjusted to 100 copies.

[Adjustment Examples 23 and 24: Production of Polyurethane Varnish]
Polyurethane resin (Pu) solid content 20.6 parts, styrene / maleic acid pigment dispersion resin 5 parts, polyethylene wax 2.3 parts, normal propanol 3.5 parts, defoaming agent 0.1 parts prepared in Synthesis Example 4. , 1.0 part of aqueous ammonia and 67.5 parts of water were stirred and mixed, and then kneaded with a bead mill to prepare a polyurethane-based varnish. It was confirmed that the viscosity of the obtained polyurethane varnish was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigo Co., Ltd.). The formulations are shown in Table 4.

[Adjustment Examples 25 and 26: Manufacture of Acrylic Polyurethane Varnish]
Acrylic polyurethane resin (Au) solid content 20.6 parts, styrene / maleic acid pigment dispersion resin 5 parts, polyethylene wax 2.3 parts, normal propanol 3.5 parts, defoaming agent 0.1 prepared in Synthesis Example 5. A part, 1.0 part of ammonia water, and 67.5 parts of water were stirred and mixed, and then kneaded with a bead mill to prepare an acrylic polyurethane-based varnish. It was confirmed that the viscosity of the obtained acrylic polyurethane varnish was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha). The formulations are shown in Table 4.

[Adjustment Examples 27 and 28: Manufacture of Acrylic White Ink]
Regarding the adjustment example 27, 18 parts of acrylic emulsion (A1) solid content, 2 parts of high acid value acrylic polymer (A2) solid content, 40 parts of titanium oxide (product name: JR-800 manufactured by TAYCA), 5 parts of polyethylene wax, After stirring and mixing 3 parts of normal propanol, 0.1 part of defoaming agent, 0.6 part of ammonia water, and 31.3 parts of water, the mixture was kneaded with a bead mill to prepare an acrylic white ink. It was confirmed that the viscosity of the obtained acrylic white ink was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha).
For Adjustment Example 28, an acrylic white ink was prepared by the same procedure as in Adjustment Example 27, except that 20 parts of the acrylic emulsion (A1) had a solid content and no high acid value acrylic polymer (A2) was added. The formulations are shown in Table 5.

[Adjustment example 29: Production of polyurethane-based indigo ink (Pu-indigo)]
Polyurethane resin (Pu) solid content 16.7 parts produced in Synthesis Example 3, FASTPGEN BLUE LA5380 indigo pigment (manufactured by DIC) 19 parts, styrene / maleic acid pigment dispersion resin 4 parts, polyethylene wax 0.6 parts, normal 2.8 parts of propanol, antifoaming agent 0. After stirring and mixing 1 part, 0.8 part of ammonia water and 56 parts of water, the mixture was kneaded with a bead mill to prepare a polyurethane indigo ink (Pu-indigo). It was confirmed that the viscosity of the obtained polyurethane-based indigo ink (Pu-indigo) was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha).

[Adjustment Example 30: Manufacture of Acrylic Polyurethane Indigo Ink (Au-Indigo)]
Acrylic polyurethane having the same composition as that of Adjustment Example 29 except that 16.7 parts of the acrylic polyurethane resin (Au) solid content prepared in Synthesis Example 4 was used instead of the polyurethane resin (Pu) of Adjustment Example 1. A system indigo ink (Au-indigo) was produced. It was confirmed that the viscosity of the obtained acrylic polyurethane-based indigo ink (Au-indigo) was 16 seconds (25 ° C.) with Zahn Cup # 4 (manufactured by Rigosha).

Tables 1 to 6 show examples of adjusting each ink and varnish.

<Manufacturing of printing ink laminate>
[Example 1]
A solid pattern of 240 mm in length × 80 mm in width is printed on a corona-treated polypropylene biaxially stretched film (Pyrene P2161 manufactured by Toyobo Co., Ltd., 20 μm in thickness) with a Flexoproof 100 test printing machine (Testing Machines, Inc., Anilox 200 line / inch). ), The polypropylene-based indigo ink according to Adjustment Example 29 and the acrylic-based varnish according to Adjustment Example 1 were printed in this order using an anilos roll and a resin plate at a printing speed of 100 m / min, and the obtained printed matter was printed at 40 ° C. for 20 hours. After aging, a printing ink laminate (P1) having a two-layer structure composed of a first printing layer and a second printing layer was obtained.

[Examples 2 to 36] [Comparative Examples 1 to 12]
A printing ink laminate (P1) having a two-layer structure composed of a first printing layer and a second printing layer shown in Tables 7 to 13 was produced by the same method as in Example 1.

[Example 37]
A solid pattern of 240 mm in length × 80 mm in width is printed on a corona-treated polypropylene biaxially stretched film (Pyrene P2161 manufactured by Toyobo Co., Ltd., 20 μm in thickness) with a Flexoproof 100 test printing machine (Testing Machines, Inc., Anilox 200 line / inch). ), A polypropylene-based indigo ink according to Adjustment Example 29, an acrylic-based white ink according to Adjustment Example 27, and an acrylic-based varnish according to Adjustment Example 1 were printed at a printing speed of 100 m / min using an anilox roll and a resin plate. After aging the printed matter at 40 ° C. for 24 hours, a printing ink laminate (P2) having a three-layer structure composed of a first printing layer, a second printing layer, and a third printing layer was obtained.

[Examples 38 to 72] [Comparative examples 13 to 24]
A printing ink laminate (P2) having a three-layer structure composed of the first printing layer, the second printing layer, and the third printing layer shown in Tables 14 to 20 was produced by the same method as in Example 37.

Using the produced two-layer structure printing ink laminate (P1) and three-layer structure printing ink laminate (P2), evaluation of substrate adhesion, abrasion resistance, water friction resistance, scratch resistance, and heat resistance was performed. In addition, the viscosity stability of the prepared acrylic resin-based ink and varnish of the present invention was also evaluated.

<Substrate adhesion>
A cellophane tape (manufactured by Nichiban Co., Ltd.) was attached to the ink-coated surface of the obtained printing ink laminate, and then the ink was strongly peeled off to visually determine the degree of ink peeling.
The practical level is △ ○ or higher.
◎: Ink did not peel off at all ○: Ink slightly peeled off from the film (less than 20%)
○ △: Ink peels off from the film (20% or more, less than 40%)
Δ: Ink peels off from the film (40% or more, less than 60%)
×: Ink peels off significantly from the film (60% or more)

<Abrasion resistance>
The obtained printed ink laminate was rubbed with high-quality paper using a Gakushin type friction resistance tester, and the degree of peeling of the ink layer was visually determined. (500 round trips with a load of 500 g)
The practical level is Δ or higher.
⊚: Ink did not peel off at all ○: Ink slightly peeled off from the film (less than 15%)
○ △: Ink peels off from the film (15% or more, less than 30%)
Δ: Ink peels off from the film (30% or more, less than 50%)
X: Ink peels off significantly from the film (50% or more)

<Water friction resistance>
The obtained printed ink laminate was rubbed with a water-containing black cotton cloth using a Gakushin type friction resistance tester, and the degree of peeling of the ink layer was visually determined. (500 round trips with a load of 200 g)
The practical level is Δ or higher.
⊚: Ink did not peel off at all ○: Ink slightly peeled off from the film (less than 15%)
○ △: Ink peels off from the film (15% or more, less than 30%)
Δ: Ink peels off from the film (30% or more, less than 50%)
X: Ink peels off significantly from the film (50% or more)

<Scratch resistance>
The ink-coated surface of the obtained printed ink laminate was scratched with a nail, and the scratch resistance was visually evaluated from the degree of damage to the coating film.
The practical level is ○ △ or higher.
◎: No scratches ○: Slight scratches ○ △: Medium scratches between ○ and △ △: Scratches ×: Significant scratches (even if the nail is vertical) Things that come off)

<Heat resistance>
The printed surface and the PET film (product name: E5102 12μ) untreated surface were crimped, and the degree of ink removal under high temperature conditions was visually evaluated using a heat seal tester. ◎: No ink was removed. ○: Slight ink is taken on the film (less than 20%)
○ △: Ink is taken on the film (20% or more, less than 40%)
Δ: Ink is taken on the film (40% or more, less than 60%)
×: Ink is significantly taken on the film (60% or more)

<Viscosity stability>
Regarding the created acrylic resin-based ink and varnish of the present invention, the viscosity after 6 hours at 25 ° C. for 15 seconds was evaluated using Zahn Cup # 4 (manufactured by Rigosha). Those that did not thicken at all (less than +1 second)
○: Ink is slightly thickened (less than +3 seconds)
○ △: Ink is slightly thickened (less than +5 seconds)
△: Ink thickened (less than +10 seconds)
×: Ink is significantly thickened (+10 seconds or more)

Tables 7 to 20 show the configurations of the obtained two-layer structure printing ink laminate (P1) and the three-layer structure printing ink laminate (P2), and the evaluation results.

From the above results, the water-based liquid ink of the present invention can provide a laminate having excellent viscosity stability, adhesion of a cured coating film to a substrate, and various coating film strengths.
Further, even in a system to which a curing agent is added, it is possible to provide a laminate having a viscosity stability comparable to that of the cured coating film, which further enhances the adhesion of the cured coating film to the substrate and the strength of various coating films.

The liquid printing ink laminate of the present invention can be widely used as various gravure and flexographic printed matter for industrial products such as food packaging materials, sanitary products, cosmetics, and electronic parts.

Claims (5)

A laminate having a plurality of printing layers on a plastic film.
A first printing layer formed of a printing ink containing a polyurethane resin or an acrylic polyurethane resin and a coloring pigment on a plastic film,
A second printing layer provided in contact with the first printing layer and formed by the water-based liquid ink (A) is provided in this order.
The water-based liquid ink (A) is a resin different from the (meth) acrylic emulsion resin (A1) in which the acid value of the entire emulsion resin is less than 50 (mgKOH / g) and the (meth) acrylic emulsion resin (A1). The solid content mass ratio with the (meth) acrylic resin (A2) having an acid value of 50 (mgKOH / g) or more is contained in the range of (A1) :( A2) = 69: 1 to 20:50. A characteristic laminate. The laminate according to claim 1, wherein the (meth) acrylic emulsion resin (A1) is a core-shell type emulsion resin. The laminate according to claim 1 or 2, wherein the water-based liquid ink (A) contains a white pigment. The water-based liquid ink according to any one of claims 1 to 3, wherein the water-based liquid ink (A) further contains an epoxy compound. The first printing layer, the second printing layer, and the third printing layer formed from the water-based liquid ink (A).
The laminated body according to any one of claims 1 to 4.