JP2006070190A - Printing ink and packaging material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a printing ink having excellent light resistance and excellent printability. <P>SOLUTION: The printing ink comprises at least a polyurethane resin (A) and a pigment (B), and either an ultraviolet absorber (C) or a light stabilizer (D) or both, and the above ultraviolet absorber (C) and light stabilizer (D) are selected from the group having an aromatic monocyclic hydrocarbon group, a condensed polycyclic aromatic hydrocarbon group, a heteromonocyclic group, and a condensed heterocyclic group and have absorptive power in the wavelength range of 200-400 nm. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  Printing ink and printed matter obtained by applying printing ink to a known general film, a laminate obtained by laminating this printed matter through a general laminating adhesive, a package processed using this laminate, and It relates to packaging materials.

Conventionally, laminates in which printing ink is applied to a thin film of polyolefin, polyester, nylon, etc., and a thin film of polyolefin, polyester, aluminum, etc. are laminated via an adhesive have been widely used as a substrate for packaging foods, pharmaceuticals, etc. ing.
JP-A-2-64173 JP-A-2-64174 JP-A-2-64175

  In some cases, products packaged with the above laminate are stored under light irradiation for a long period of time. When opening a laminate that has been stored for a long time under light irradiation, the laminate strength of the printing ink coating film is reduced due to the influence of radicals generated under these conditions. There is a concern about the problem of occurrence of phase separation. An object of the present invention is to provide a printing ink having excellent light resistance and excellent printability.

  As a result of intensive studies to solve the above-mentioned problems, the present inventors have secured light resistance by using an ultraviolet absorber and / or a light stabilizer in combination, and the polyurethane resin containing a specific component is an ester, Gravure inks having good solubility in alcohol solvents and using the resin as a main binder have been found to improve printability such as reproducibility of tone parts and plate fogging, and have completed the present invention. .

That is, the present invention is a printing ink containing at least a polyurethane resin (A) and a pigment (B), and includes either or both of an ultraviolet absorber (C) and a light stabilizer (D). It is printing ink characterized by including.
In the present invention, the ultraviolet absorber (C) and the light stabilizer (D) are an aromatic monocyclic hydrocarbon group, a condensed polycyclic aromatic hydrocarbon group, a heteromonocyclic group, and a condensed heterocyclic group. The above printing ink is selected from the group having, and has an absorptivity in a wavelength range of 200 to 400 nm.

In the present invention, the ultraviolet absorber (C) is a benzotriazole-based ultraviolet absorber having an ethylenically unsaturated bond, a benzophenone-based ultraviolet absorber, a salicylic acid-based ultraviolet absorber, a cyanoacrylate-based ultraviolet absorber, a hindered Either a phenolic UV absorber, a triazine UV absorber, or a combination of two or more, and the light stabilizer (D) is either a hindered amine light stabilizer, a benzoate light stabilizer, or 2 It is the above-mentioned printing ink that is used in combination of more than one kind and the LD _{50 of the} ultraviolet absorber (C) and the light stabilizer (D) is 2000 mg / kg or more.
In the present invention, the content of the ultraviolet absorber (C) is 0.5 to 10 parts by weight and the content of the light stabilizer (D) is 0.5 to 10 parts with respect to 100 parts of the printing ink. The printing ink according to claim 1, wherein the printing ink is part by weight.

Furthermore, the present invention is the above printing ink that uses an antioxidant (E) and / or a processing heat stabilizer (F) as an additive.
Furthermore, the present invention provides 15 parts or more and 60 parts of polypropylene glycol (PPG) having a hydroxyl value of 112.0 to 28.0 (number average molecular weight 1000 to 4000) in the resin with respect to 100 parts of the polyurethane resin (A). It is the said printing ink containing the polyurethane resin (A) characterized by including less.

Furthermore, the present invention provides the printing ink, wherein the polyurethane resin (A) has an amine value of 1 to 10 mgKOH / resin 1 g and a hydroxyl value of 0.05 to 5.0 mgKOH / resin 1 g.
Furthermore, the present invention is a printed matter coated with the above printing ink.

In addition, this invention relates to the laminated body which laminated the printed matter which apply | coated the said printing ink to the film (G) through the lamination adhesive agent.
In addition, the present invention relates to a package or a packaging material processed using the laminate.

  According to the present invention, a printing ink having excellent light resistance and excellent printability was obtained.

  Each component in the printing ink having light resistance of the present invention will be described below.

  Examples of the polyurethane resin (A) in the present invention include polyurethane resins used in general inks, paints, and recording agents.

  The polyurethane resin (A) of the present invention can be produced by a conventionally known method, for example, JP-A-62-153366, JP-A-62-153367, JP-A-1-236289, JP-A-2-64173. The methods disclosed in JP-A-2-64174, JP-A-2-64175 and the like can be used. Specifically, a polyol and a diisocyanate compound are reacted in an excess ratio of isocyanate groups to obtain a prepolymer of a terminal isocyanate group, and the obtained prepolymer is usually used as a solvent for an ink, that is, as a solvent for ink. Used ester solvents such as ethyl acetate, propyl acetate and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; alcohol solvents such as methanol, ethanol, isopropyl alcohol and n-butanol; toluene and methylcyclohexane , Hydrocarbon solvents such as ethylcyclohexane; or a mixed solvent thereof in a two-stage process with a chain extender and / or end-capping agent, or a polyol, diisocyanate compound, chain extender and / or terminal A chain agent is prepared by one-step process of reacting at a time in a suitable solvent of the above. Among these methods, it is preferable to use a two-stage method in order to obtain a uniform polyurethane resin. Moreover, when producing a polyurethane resin by a two-stage method, it is preferable to make it react so that the sum (equivalent ratio) of the amino group of a chain extender and / or terminal blocker may become a ratio of 1 / 0.9-1.3. If the equivalent ratio of isocyanate group to amino group is less than 1 / 1.3, the chain extender and / or end-capping agent will remain unreacted, the polyurethane resin will turn yellow, and odor will occur after printing. Sometimes.

Ｒ１、Ｒ２：ウレタン結合およびまたはウレア結合を含むポリウレタン樹脂部分
ｎ ： １７から６８の整数 The polyurethane resin (A) of the present invention comprises 15 parts or more of polypropylene glycol (PPG) having a hydroxyl value of 112.0 to 28.0 (number average molecular weight Mw 1000 to 4000) in the resin with respect to 100 parts of the polyurethane resin. What is characterized by including less than a part is preferable. That is, it has a portion represented by the following chemical formula (1) in the resin skeleton.

R1, R2: polyurethane resin part containing urethane bond and / or urea bond
n: integer from 17 to 68

The polyurethane resin (A) of the present invention is composed of polypropylene glycol (PPG) having a hydroxyl value of 112.0 to 28.0 (number average molecular weight Mw 1000 to 4000), if necessary, a combined polyol, a diisocyanate compound, a chain extender, and necessary Depending on the case, it can be obtained by reacting a terminal blocking agent or the like. It is a polyurethane resin that is soluble in organic solvents, particularly solvents such as esters, ketones, and alcohols.
When the hydroxyl value of polypropylene glycol (PPG), which is a component of the polyurethane resin of the present invention, is 112.0 larger (number average molecular weight is smaller than 1000), the film of the polyurethane resin tends to be hard and the adhesion to the polyester film is high. Inferior. On the other hand, when the hydroxyl value 28.0 is small (number average molecular weight is greater than 4000), the polyurethane resin film tends to be brittle and the ink film has poor blocking resistance.
If the amount of polypropylene glycol (PPG) is less than 15 parts with respect to 100 parts of the polyurethane resin, the solubility of the urethane resin in ketones, esters and alcohol-based solvents tends to be inferior. The solubility tends to be inferior, and the tone reproducibility of the printed matter is inferior. Moreover, after laminating | printing a printing film as it is 60 parts or more, it exists in the tendency for peeling strength to be inferior.

  As the combined polyol used as necessary in the polyurethane resin of the present invention, various known polyols generally used for the production of polyurethane resins can be used, and one or two or more kinds may be used in combination. . For example, polyether polyols (1) of polymers or copolymers such as methylene oxide, ethylene oxide, and tetrahydrofuran; ethylene glycol, 1,2-propanediol, 1,3-propanediol, and 2-methyl-1,3-propane Diol, 2ethyl-2butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4- Butanetriol, sorbitol, Saturated or unsaturated low molecular polyols such as pentaesitol (2); these low molecular polyols (2) and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, fumaric acid, succinic acid , Oxalic acid, malonic acid, glutaric acid, pimelic acid, speric acid, azelaic acid, sebacic acid, trimellitic acid, pyromellitic acid and other polycarboxylic acids such as dehydration condensation or polymerization Polyester polyols (3); Polyester polyols (4) obtained by ring-opening polymerization of cyclic ester compounds such as lactones such as polycaprolactone, polyvalerolactone and poly (β-methyl-γ-valerolactone); The low molecular polyols (2) and the like, for example, dimethyl carbonate, diphenyl carbonate; Polycarbonate polyols obtained by reaction with ethylene carbonate, phosgene, etc. (5); polybutadiene glycols (6); glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A (7); Acrylic polyol (1) obtained by copolymerizing one or more hydroxyethyl, hydroxypropyl acrylate, acrylhydroxybutyl, etc., or their corresponding methacrylic acid derivatives and the like with, for example, acrylic acid, methacrylic acid or esters thereof. 8).

  Of the polyester polyols (3), a polymer diol obtained from a diol (glycols) and a dibasic acid is a low molecular weight compound having up to 5 mol% of the diols having three or more hydroxyl groups. The polyols (2) can be substituted.

  Examples of the diisocyanate compound used in the polyurethane resin of the present invention include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are generally used in the production of polyurethane resins. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, cyclohexane-1 , 4-Diisocyanate, Xylylene diisocyanate, Isophorone diisocyanate, Dimeryl diisocyanate, Dicyclohexane Silmethane-4,4'-diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, bis-chloromethyl -Diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, dimerized isocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group, and the like. These diisocyanate compounds can be used alone or in admixture of two or more.

  Examples of the chain extender used in the polyurethane resin of the present invention include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, and 2-hydroxyethyl. Ethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypropylethylenediamine, di-2 An amine having a hydroxyl group in the molecule such as hydroxypropylpyrethylenediamine or di-2-hydroxypropylethylenediamine can also be used. These chain extenders can be used alone or in admixture of two or more.

  Moreover, a monovalent active hydrogen compound can also be used as a terminal blocking agent for the purpose of stopping the reaction. Examples of such compounds include dialkylamines such as di-n-butylamine and alcohols such as ethanol and isopropyl alcohol. Furthermore, amino acids such as glycine and L-alanine can be used as a reaction terminator, particularly when it is desired to introduce a carboxyl group into the polyurethane resin. These end blockers can be used alone or in admixture of two or more.

  The polyurethane resin (A) thus obtained preferably has a crosslinkable functional group such as an amino group or a hydroxyl group. The amino group-containing polyurethane resin can be obtained, for example, by adjusting the amount of amine chain extender and / or end-capping agent during the synthesis of the polyurethane resin so that the terminal of the polyurethane resin is an amino group. The hydroxyl group-containing polyurethane resin can be obtained, for example, by using amines having a hydroxyl group in the molecule as a chain extender. The amine value of the polyurethane resin is preferably in the range of 1 to 10 mgKOH / resin 1 g and the hydroxyl value is in the range of 0.05 to 5.0 mgKOH / resin 1 g. When it is below the above range, crosslinking is likely to be insufficient, and when it is above the above range, the solvent resistance of the polyurethane resin tends to be poor.

The weight average molecular weight of the polyurethane resin thus obtained is preferably in the range of 15,000 to 100,000. When the weight average molecular weight of the polyurethane resin is less than 15,000, there is a tendency that the blocking resistance of the ink composition obtained, the strength of the printed film, the oil resistance, and the like tend to be low. The viscosity of the resulting ink composition tends to increase, and the gloss of the printed film tends to decrease.
The content of the polyurethane resin (A) of the present invention in the ink is 4% by weight or more with respect to the total weight of the ink from the viewpoint of sufficient adhesion of the ink to the printing medium, at a suitable ink viscosity or at the time of ink production. -25 weight% or less is preferable from a viewpoint of the work efficiency at the time of printing, and also the range of 6-15 weight% is preferable.

  Examples of the pigment (B) used in the present invention include organic and inorganic pigments and dyes used in general inks, paints, and recording agents. Examples of organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, dictopyrrolopyrrole, and isoindoline. Pigments. From the viewpoint of cost and light resistance, it is preferable to use C. I. Pigment No Yellow 83 for the indigo ink and copper phthalocyanine for the transparent yellow ink.

Examples of the inorganic pigment include carbon black, titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, bengara, aluminum, mica (mica), and the like. From the viewpoints of cost and coloring power, it is preferable to use titanium oxide for white ink, carbon black for black ink, aluminum for silver ink, and mica for pearl ink. Aluminum is in the form of powder or paste, but is preferably used in the form of paste from the viewpoint of handling and safety, and whether to use leafing or non-leafing is appropriately selected from the viewpoint of brightness and concentration.
The pigment is preferably contained in an amount sufficient to ensure the concentration and coloring power of the ink, that is, in a proportion of 1 to 50% by weight based on the total weight of the ink. Moreover, a pigment can be used individually or in combination of 2 or more types.

  In order to stably disperse the pigment in the organic solvent, it is possible to disperse the resin alone, but it is also possible to use a dispersant in order to disperse the pigment stably. As the dispersant, anionic, nonionic, cationic, amphoteric surfactants can be used. The dispersant is preferably contained in the ink in an amount of 0.05% by weight or more based on the total weight of the ink from the viewpoint of the storage stability of the ink and 5% by weight or less from the viewpoint of the suitability for lamination. .1 to 2% by weight.

  The ultraviolet absorber (C) and the light stabilizer (D) used in the present invention have an aromatic monocyclic hydrocarbon group, a condensed polycyclic aromatic hydrocarbon group, a heteromonocyclic group, and a condensed heterocyclic group. It is selected from the group and has an absorptivity in a wavelength range of 200 to 400 nm.

図２ ベンゾフェノン骨格

図３ サリチル酸骨格

図４ シアノアクリレート骨格

図５ ヒンダードフェノール骨格

図６ トリアジン骨格

More specifically, the ultraviolet absorber (C) used in the present invention includes a benzotriazole-based ultraviolet absorber including a benzotriazole skeleton having an ethylenically unsaturated bond, a benzophenone-based ultraviolet absorber including a benzophenone skeleton, and salicylic acid as a skeleton. Either a salicylic acid UV absorber containing, a cyanoacrylate UV absorber containing a cyanoacrylate skeleton, a hindered phenol UV absorber containing a hindered phenol skeleton, or a triazine UV absorber containing a triazine skeleton It can be used in combination.
Specific structures of these skeletons are shown below.
Fig. 1 Benzotriazole skeleton

Fig. 2 Benzophenone skeleton

Fig. 3 Salicylic acid skeleton

Fig. 4 Cyanoacrylate skeleton

Fig. 5 Hindered phenol skeleton

Fig. 6 Triazine skeleton

図８ ベンゾエート骨格

More specifically, the light stabilizer (D) used in the present invention is either a hindered amine light stabilizer containing a hindered amine in the skeleton, a benzoate light stabilizer containing benzoate in the skeleton, or a combination of two or more types. Can be used.
Specific structures of these skeletons are shown below.
Fig. 7 Hindered amine skeleton

Fig. 8 Benzoate skeleton

The UV absorber (C) and the light stabilizer (D) used in the present invention preferably have an LD ₅₀ of 2000 mg / kg or more from the viewpoint of safety.

  The ultraviolet absorber (C) used in the present invention absorbs the irradiated ultraviolet rays to prevent the coating film from being deteriorated due to the ultraviolet rays. The content of the ultraviolet absorber (C) is preferably 0.5 to 10% by weight, more preferably 1 to 3% by weight, based on the total amount of ink. When the content of the UV absorber (C) is less than 0.5%, the laminate strength tends to deteriorate due to the deterioration of the coating film after UV irradiation. When the content is 10% by weight or more, the flexibility of the resin contained in the ink By inhibiting the property, initial adhesion to the printed matter may be inhibited. The ultraviolet absorber (C) can be used alone or in combination of two or more.

The light stabilizer (D) used in the present invention absorbs radicals generated in the coating film when irradiated with energy rays such as ultraviolet rays, thereby preventing deterioration of the coating film caused by radical generation. Is. The content of the light stabilizer (D) is preferably 0.5 to 10% by weight, more preferably 1 to 3% by weight, based on the total amount of the ink. When the light stabilizer (D) content is less than 0.5%, the laminate strength tends to deteriorate due to the deterioration of the coating film after UV irradiation. When the content is 10% by weight or more, the resin contained in the ink By inhibiting flexibility, initial adhesion to printed matter may be inhibited. The light stabilizer (D) can be used alone or in combination of two or more.

The printing ink of the present invention can be used in combination with an antioxidant (E) as an additive as required.
As the antioxidant (E), generally used benzothiazole type and high molecular weight amine type antioxidants can be used.

The printing ink of the present invention can be used in combination with a processing heat stabilizer (F) as an additive as required.
As the processing heat stabilizer (F), a commonly used phosphorus / lactone blend processing heat stabilizer can be used.

  The printing ink of the present invention contains a polyurethane resin (A) as an essential component and contains a pigment (B), an ultraviolet absorber (C) and / or a light stabilizer (D), but further functions required as an ink. Therefore, a colorant, a combination resin, an organic solvent, and the like can be included. In addition, extender pigments, pigment dispersants, leveling agents, antifoaming agents, waxes, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, and the like can be included as necessary.

  Examples of resins used in combination with the ink of the present invention as needed include polyurethane resins other than the present invention, vinyl chloride-vinyl acetate copolymer resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate. Resin, polyamide resin, nitrocellulose resin, acrylic resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin modified maleic acid resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, petroleum resin, etc. be able to. The combined resins can be used alone or in admixture of two or more. The content of the combined resin is preferably 1 to 25% by weight, more preferably 2 to 15% by weight, based on the total weight of the ink.

  The ink of the present invention can be produced by dissolving and / or dispersing a resin, a colorant and the like in an organic solvent. Specifically, a pigment dispersion in which a pigment is dispersed in an organic solvent with a polyurethane resin (A) is produced, and ink is produced by blending the obtained pigment dispersion with other compounds as necessary. can do.

  In addition, as a method of incorporating an ultraviolet absorber and / or a light stabilizer in the ink of the present invention, it is added at the time of ink production, added immediately before using the ink, or a viscosity suitable for printing with a diluent solvent. There are methods such as adding to diluted ink after dilution. The content of the ultraviolet absorber and / or the light stabilizer varies depending on whether the calculation is based on the ink (base ink) or the diluted ink. In the present invention, the content is calculated based on the ink (base ink).

The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the grinding media of the disperser, the filling rate of the grinding media, the dispersion treatment time, the discharge speed of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. As a disperser, generally used, for example, a roller mill, a ball mill, a pebble mill, an attritor, a sand mill and the like can be used.
In the case where bubbles or unexpectedly large particles are included in the 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 ink viscosity produced by the above method is 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. preferable. In addition, the said viscosity is a viscosity measured at 25 degreeC with the Tokimec B-type viscometer.
The viscosity of the ink can be adjusted by appropriately selecting the type and amount of raw materials used, for example, a polyurethane resin, a colorant, an organic solvent, and the like. The viscosity of the ink can also be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

  As the hue of the ink of the present invention, there are five basic colors of yellow, red, indigo, black, and white, depending on the type of colorant used, and red (orange) and grass (colors outside the process gamut) There are three colors, green) and purple. Further, transparent yellow, peony, vermilion, brown, gold, silver, pearl, almost transparent medium for adjusting color density (including extender pigments if necessary), etc. are prepared as base colors. The base ink of each hue is diluted with a diluting solvent to a viscosity and density suitable for printing, and is supplied alone or mixed to each printing unit.

  The printing ink of the present invention can be printed on a thin film of polyolefin, polyester, nylon or the like by a printing method according to the application.

The printed matter to which the printing ink of the present invention is applied can be a laminate obtained by laminating polyolefin, polyester, aluminum or the like via a general laminate adhesive. These laminates can be widely used as a base material for packaging foods and pharmaceuticals.
[Example]

The present invention will be described more specifically with reference to examples. Hereinafter, both “parts” and “%” are based on weight.
In addition, a hydroxyl group is the number of mg of potassium hydroxide required in order to neutralize the hydroxyl group contained in 1g of resin, and is the value performed according to JISK0070. The amine value is the number of mg of potassium hydroxide equivalent to hydrochloric acid required to neutralize the amino group contained in 1 g of resin. The method for measuring the amine value was as described below. The molecular weight was determined as a polystyrene-converted molecular weight by measuring the molecular weight distribution using a GPC (gel permeation chromatography) apparatus. The viscosity was measured at 25 ° C. with a Tokimec B-type viscometer.

(Synthesis Example 1)
147.1 parts of polyester diol (PMPA4000) having a number average molecular weight (hereinafter referred to as Mn) of 4,000 obtained from adipic acid and 3-methyl-1,5-pentadiol, 97.0 parts of polypropylene glycol (PPG2000) of Mn2000, 39.7 parts of isophorone diisocyanate and acetic acid 90 parts of ethyl was reacted at 90 ° C. for 6 hours under a nitrogen stream to obtain 373.8 parts of a solvent solution of a terminal isocyanate prepolymer. Next, 15.8 parts of isophoronediamine, 0.3 part of 2-hydroxyethylethylenediamine, 0.1 part of di-n-butylamine, 330 parts of ethyl acetate and 280 parts of isopropyl alcohol were mixed with 473 parts of the solvent solution of the resulting terminal isocyanate prepolymer. Gradually added at room temperature, and then reacted at 50 ° C. for 1 hour to obtain a polyurethane resin solution A having a solid content of 30%, an amine value of 1.0 mg KOH / resin, 1 g of hydroxyl value, 0.2 mg KOH / resin of 1 g, and a viscosity of 8 P at 25 ° C. It was.

(Synthesis Examples 2-8)
Using the raw materials shown in Table 1, polyurethane resin solutions B to I were obtained in the same manner as in Synthesis Example 1.

[Example 1]
Indigo ink is a mixture of 12 parts of copper phthalocyanine indigo, 40 parts of polyurethane resin solution A, 42 parts of methyl ethyl ketone, and 6 parts of isopropyl alcohol. White ink is 30 parts of titanium oxide white, 50 parts of polyurethane resin solution A, 14 parts of methyl ethyl ketone, isopropyl alcohol. Six parts of the mixture were kneaded with a ball mill for 20 hours to obtain indigo blue and white gravure ink (base ink).

For each 100 parts of the base ink, Octlyl-3- [3-t-butyl-4-hydoroxy-5- (5-chloro-2H-benzotriazol-2-yl) propionate2-Ethylhexyl-3- [3-t -Butyl-4-hydroxy-5- (5-chloro-2H-benzotriazol-2-yl) phenyl] propionate (benzotriazole) 3.0 parts, and 40% methyl ethyl ketone, isopropyl to adjust the viscosity during printing Using a mixed solvent consisting of 30% alcohol, 20% propyl acetate, and 10% ethyl acetate, the mixture is diluted at 25 ° C so that the viscosity measured with Zahn Cup No. 3 is 18 seconds. Diluted ink) was obtained.

A re-dissolution test was performed using the diluted indigo and white gravure inks, and the results are shown in Table 2. The test method was performed as described later.
Next, using the diluted gravure indigo ink, a gravure printing plate equipped with a gravure gradation plate having a plate depth of 35 μm to 3 μm (35 μm to 10 μ is engraved in 10 μm and 10 μm to 3 μm is engraved in 1 μm increments) Printed on the corona discharge-treated surface of a 12 μm corona discharge-treated polyethylene terectrate film “E5100” (trade name, manufactured by Toyobo Co., Ltd.) and dried at a dryer temperature of 40 ° C. to 50 ° C. Using the diluted gravure white ink for cans continuously, printing was performed by a gravure printing machine equipped with a gravure solid plate having a plate depth of 35 μm to obtain a printed film on which indigo white was overlaid.
The obtained printed film was evaluated for the reproducibility of the toned portion of the indigo portion, and the results are shown in Table 2. The evaluation method was performed as described later.
Further, in the 35 μm indigo white printing portion of the obtained printing film, an initial adhesion test for printed matter was performed, and the results are shown in Table 2. The test method was performed as described later.
Next, the printed film was used and laminated with a polyethylene film using polyethylene as a molten resin by an extrusion laminating method to prepare a laminate. Lamination conditions were performed as described below.
Next, using the laminate, the laminate strength was measured and the laminate strength of the laminate irradiated with ultraviolet rays for 40 hours was measured with a fed meter. The results are shown in Table 2. The evaluation method was performed as described later.

[Examples 2 to 13 and Comparative Examples 1 to 3]
An ink (base ink) was prepared in the same manner as in Example 1 using a polyurethane resin synthesized by the composition shown in Table 1. Furthermore, the ultraviolet absorber shown in Table 2 and the light stabilizer were added, and it diluted with the mixed solvent similar to Example 1, and obtained indigo and white gravure ink (dilution ink). Using the diluted ink, printing and laminating were performed in the same manner as in Example 1 to obtain a laminate. The same evaluation was performed for each. The results are shown in Table 2.

The method for measuring the amine value is as follows.
[Method for measuring amine value]
Weigh 0.5-2 g of sample accurately. (Sample amount: Sg) 30 mL of neutral ethanol (BDG neutral) is added to a precisely weighed sample and dissolved. The obtained solution is titrated with a 0.2 mol / L ethanolic hydrochloric acid solution (titer: f). The point at which the color of the solution changed from green to yellow was taken as the end point, and the amine value was determined by the following formula (1) using the titration amount (AmL) at this time.
(1)

The conditions for each performance evaluation are as follows.
[Re-solubility test]
After applying the prepared gravure ink to a polyester film and drying it, dissolve the coated surface with a mixed solvent consisting of 40% methyl ethyl ketone, 30% isopropyl alcohol, 20% propyl acetate, 10% ethyl acetate, Visual evaluation was made on a five-point scale, with the ink that dissolves quickly being considered good. 100% dissolves when the mixed solvent is flowed less than 5 times (◯), 100% dissolves 5 times or less and less than 10 times (◯ △), 100% dissolves 10 times or less and less than 15 times (△), The case where 80 times or more dissolves by 15 times (Δx), and the case where the insoluble part remains by 15 times and 20% or more remains is (x), and the pass levels are ○ and ○ Δ.
[Evaluation of reproducibility of tone part]
In the obtained printed matter, the halftone dot reproducibility of the 10 μm to 3 μm portion of the indigo ink was evaluated with a magnifier or visually. It is assumed that halftone dot reproducibility is obtained with halftone dots of 95% or more reproduced at each plate depth. Those having a halftone dot reproducibility of 3 μm to 4 μm are acceptable levels.

[Initial adhesion test for printed matter]
Apply the cello tape (Nichiban, registered trademark, width 12mm) to the 35μm portion of the printed material immediately after printing and rub it strongly with the thumb 5 times. The degree of was investigated. The state of ink transfer to the tape was evaluated in the following five levels. 100% of ink does not transfer to tape (○), about 20% of ink is transferred to the tape part that has been abruptly separated, but 100% of the part that has been slowly peeled off (○ △), the part of the tape that has been peeled off abruptly 100% ink is transferred to the surface of the tape, but the part that is slowly peeled off does not transfer 100% (triangle), 100% ink is transferred to the tape part that is abruptly peeled off, and about 20% of the ink is transferred to the part that is slowly peeled off. There is a degree (Δx), and the portion where the tape is stretched is 100% transferred (x), the practical level is ○, ○ Δ, and the desirable pass level is ○.

[Extrusion Laminate]
The produced printed material was laminated with an extrusion laminator under the following conditions. EL451 (Toyo Morton butadiene anchor agent) as a 10% solution was applied to the printed surface as an anchor agent, LC500 (manufactured by Nippon Polychem) was used as the molten resin, and TUX-FCD film thickness of 40 μm (manufactured by Tosero) was used as the sealant. The molten resin temperature was 315 ° C., and the resin film thickness was 20 μm.

[Measurement of laminate strength]
The laminate was cut at a width of 15 mm and peeled between the ink surface and the molten resin layer, and the peel strength was measured with an Intesco 2010 universal tensile tester.
[Measurement of laminate strength after UV irradiation with a fed meter]
The laminate was irradiated with ultraviolet rays for 40 hours with a fedometer (ultraviolet carbon arc lamp type light resistance tester), and the laminate strength after irradiation was measured by the same method as the laminate strength measurement. Moreover, the conditions of ultraviolet irradiation followed JIS L0842-7.2 and JIS B7751.

Claims (10)

A printing ink containing at least a polyurethane resin (A) and a pigment (B), wherein the printing ink contains one or both of an ultraviolet absorber (C) and a light stabilizer (D). Printing ink. The ultraviolet absorber (C) and the light stabilizer (D) are selected from the group having an aromatic monocyclic hydrocarbon group, a condensed polycyclic aromatic hydrocarbon group, a heterocyclic monocyclic group, and a condensed heterocyclic group. The printing ink according to claim 1, which has an absorptivity in a wavelength range of 200 to 400 nm. The UV absorber (C) is a benzotriazole UV absorber having an ethylenically unsaturated bond, a benzophenone UV absorber, a salicylic acid UV absorber, a cyanoacrylate UV absorber, a hindered phenol UV absorber, Either triazine-based UV absorber or a combination of two or more, and light stabilizer (D) is either a hindered amine-based light stabilizer, a benzoate-based light stabilizer, or a combination of two or more The printing ink according to claim 1, wherein the LD _{50 of the} ultraviolet absorber (C) and the light stabilizer (D) is 2000 mg / kg or more. The content of the ultraviolet absorber (C) is 0.5 to 10 parts by weight and the content of the light stabilizer (D) is 0.5 to 10 parts by weight with respect to 100 parts of the printing ink. The printing ink according to claim 1, wherein the printing ink is a printing ink. The printing ink according to any one of claims 1 to 4, wherein an antioxidant (E) and / or a processing heat stabilizer (F) is used as an additive. 15 parts by weight or more and less than 60 parts by weight of polypropylene glycol (PPG) having a hydroxyl value of 112.0 to 28.0 (number average molecular weight 1000 to 4000) is contained in the resin with respect to 100 parts by weight of the polyurethane resin (A). The printing ink according to claim 1, comprising a polyurethane resin (A) characterized by The printing ink according to claim 1, wherein the polyurethane resin (A) has an amine value of 1 to 10 mgKOH / resin 1 g and a hydroxyl value of 0.05 to 5.0 mgKOH / resin 1 g. A printed matter coated with the printing ink according to claim 1. The laminated body which laminated the printed matter which applied the printing ink in any one of Claim 1 thru | or 7 to the film (G) through the lamination adhesive agent. A package or a packaging material processed using the laminate according to claim 9.