JP7156895B2 - Printing ink for laminate - Google Patents

Description

The present invention relates to a printing ink for lamination that can be used as a gravure ink for flexible packaging or a flexographic ink, and more specifically, a printing ink for lamination for film substrates that exhibits good plate clogging resistance, excellent adhesion to film substrates, and excellent lamination strength. It relates to printing inks.

BACKGROUND ART In recent years, gravure inks and flexographic inks have been widely used for the purpose of imparting functionalities such as cosmetic properties and surface protection to printed materials of flexible packaging films. When the substrate to be printed by gravure printing or flexographic printing uses a plastic film as a base material, especially among packaging materials, the diversification of the film base material affects adhesion to the base material, print quality, and print workability. Ink fluidity, etc. are required. In addition, in the case of applying dry lamination using a urethane-based adhesive or the like after printing to impart film strength and airtightness, post-processing aptitude such as lamination strength is also required.

For example, printing inks containing chlorinated polypropylene as a main resin have been conventionally used because of their high adhesion to substrates and low raw material costs (eg, Patent Documents 1 to 6). And, it is said that pigment dispersibility is improved by using an acid-modified chlorinated polyolefin resin as a pigment dispersing resin (for example, Patent Document 2).
In addition, studies have been made to improve printability even when toluene, which has high solubility, is not contained (for example, Patent Documents 3 to 5).
Furthermore, Patent Document 6 is cited as an improvement in plate clogging resistance, but the improvement in plate clogging is still not sufficient. There is a demand for the development of a printing ink for lamination of film substrates, which has excellent printability and lamination strength suitable for post-processing.

Japanese Patent No. 2506404 Japanese Patent Application Laid-Open No. 2002-294128 JP-A-2006-57056 Japanese Patent No. 4672335 Japanese Patent No. 4672336 JP 2016-188274 A

An object of the present invention is to provide a printing ink for laminating that has adhesion to a film base material, printability with excellent highlight transferability without staining of non-printed areas even in high-speed printing, and lamination strength that is suitable for post-processing.

The printing ink for laminate of the present invention comprises a chlorinated polyolefin (A), an ethylene-vinyl acetate copolymer (B1) and/or a chlorinated ethylene-vinyl acetate copolymer (B2), a fatty acid derivative (C), and an organic It has been found that a printing ink for laminate containing a solvent (D) and further containing an appropriate amount of a fatty acid derivative (C) is effective in solving the problem.

That is, the present invention comprises a chlorinated polyolefin (A), an ethylene-vinyl acetate copolymer (B1) and/or a chlorinated ethylene-vinyl acetate copolymer (B2), a fatty acid derivative (C), and an organic solvent (D). and wherein the total amount of the fatty acid derivative (C) is 0.1 to 5% by mass of the total amount of the ink.

Furthermore, the present invention relates to a printing ink for lamination, wherein the long-chain hydrocarbon group of the fatty acid derivative (C) has 12 or more carbon atoms.

Further, the present invention relates to a printing ink for lamination, wherein the fatty acid derivative (C) is one or more compounds selected from the group consisting of fatty acids, fatty acid salts, fatty acid esters and fatty acid amines.

Furthermore, the present invention relates to a printing ink for lamination in which the organic solvent (D) does not contain an aromatic hydrocarbon solvent.

Furthermore, the present invention relates to a printed matter obtained by printing a plastic film with the printing ink for lamination using a gravure printing machine.

According to the present invention, there is provided a printing ink for lamination that has both film adhesion, printability with high highlight transferability without staining of non-printed areas even in high-speed printing, and lamination strength with post-processing suitability, and printing with the printing ink. We can provide various printed materials.

The present invention will be described in detail. The term "ink" used in the following description all means "printing ink for lamination". All "parts" indicate "parts by mass", and all "%" indicate "% by mass".

The printing ink for laminate of the present invention comprises a chlorinated polyolefin (A), an ethylene-vinyl acetate copolymer (B1) and/or a chlorinated ethylene-vinyl acetate copolymer (B2), a fatty acid derivative (C), and an organic A printing ink for laminate containing a solvent (D), wherein the total amount of the fatty acid derivative (C) is 0.1 to 10% by mass of the total amount of the ink.

The chlorinated polyolefin (A) used in the printing ink for laminate of the present invention will be described. The chlorinated polyolefin (A) can be obtained by introducing a chlorine atom into a polyolefin, but the polyolefin is not particularly limited. Resins composed of copolymers or homopolymers of unsaturated hydrocarbons can be used. Examples of the copolymer include propylene-α-butene copolymer, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, ethylene-vinyl acetate copolymer, ethylene-1-butene copolymer, and polyethylene. , poly-4-methyl-1-pentene, and the like.

Methods for producing chlorinated polyolefin (A) include a solution chlorination method in which polyolefin is dissolved in an organic solvent such as carbon tetrachloride and chlorinated, a method in which polyolefin is chlorinated in an aqueous suspension, and a polyolefin in a block state. Any method such as chlorination may be used.
The chlorinated polyolefin (A) may be an acid-modified chlorinated polyolefin resin obtained by introducing α,β-unsaturated carboxylic acid and/or a derivative thereof and chlorine into polyolefin.
Furthermore, as a method for producing the acid-modified chlorinated polyolefin, for example, polyolefin is acid-modified with an α,β-unsaturated carboxylic acid and/or a derivative thereof to obtain an acid-modified polyolefin, and then a chlorinated solvent such as chloroform is added. Chlorine may be introduced into the acid-modified polyolefin by blowing in chlorine gas after dissolving in the acid-modified polyolefin.

Examples of the α,β-unsaturated carboxylic acid and/or derivative thereof include fumaric acid, maleic acid, maleic anhydride, citraconic acid, citraconic anhydride, mesaconic acid, itaconic acid, itaconic anhydride, aconitic anhydride, Examples include aconitic acid, hymic anhydride, (meth)acrylic acid, (meth)acrylic acid esters, and the like.

As the chlorinated polyolefin (A) used in the printing ink for laminate of the present invention, a chlorinated polyolefin having a chlorine content of 5 to 50% by mass is preferably used.
A typical example of the chlorinated polyolefin (A) is a chlorinated polypropylene resin. The chlorinated polypropylene resin preferably has a degree of chlorination of 30 to 45% and a weight average molecular weight of 5,000 to 50,000.
The degree of chlorination is mass % of chlorine atoms in the chlorinated polypropylene resin. If the degree of chlorination is less than 30%, the solubility in organic solvents tends to decrease, and if it exceeds 45%, the adhesion to the film substrate tends to decrease. If the weight-average molecular weight is less than 5,000, it is difficult to obtain the effect of adhesion to the film substrate.

The ethylene-vinyl acetate copolymer (B1) used in the printing ink for laminate of the present invention is
It is a resin containing specific amounts of structural units derived from ethylene and structural units derived from vinyl acetate.
The ethylene-vinyl acetate copolymer (B1) preferably has a vinyl acetate content of 20% by mass or more and 50% by mass or less based on the total copolymer. When the vinyl acetate content is 20% by mass or more, the adhesion and transferability of the ink film tend to be maintained. can hold.
Furthermore, it is more preferable that the content of vinyl acetate is 30% by mass or more and 40% by mass or less based on the total copolymer.
The content of structural units derived from vinyl acetate conforms to the measurement method specified by JIS K7192:1999.

The chlorinated ethylene-vinyl acetate copolymer (B2) used in the present invention is obtained by further introducing chlorine atoms into the ethylene-vinyl acetate copolymer (B1) to obtain a chlorinated ethylene-vinyl acetate copolymer (B2). is possible.

The printing ink for laminate of the present invention may contain either the ethylene-vinyl acetate copolymer (B1) or the chlorinated ethylene-vinyl acetate copolymer (B2). good.
In particular, when a hydrocarbon solvent such as methylcyclohexane is used in the printing ink for laminate of the present invention, the combined use of the ethylene-vinyl acetate copolymer (B1) and the chlorinated ethylene-vinyl acetate copolymer (B2) results in It is more preferable from the viewpoint of clogging property, lamination strength and adhesiveness. The ratio of the ethylene-vinyl acetate copolymer to the chlorinated ethylene-vinyl acetate copolymer is more preferably 10/90 to 40/60 in solid content weight ratio.

The fatty acid derivative (C) used in the printing ink for laminate of the present invention will be described. It is essential that the amount of the fatty acid derivative (C) added is in the range of 0.1 to 5 mass % of the total amount of the ink. When the fatty acid derivative (C) is added in an amount of 0.1% by mass or more, the adhesion and transferability of the ink film tend to be maintained.
Examples of the fatty acid derivative (C) include compounds such as fatty acids, fatty acid salts, fatty acid esters, and fatty acid amines.

Further, as the fatty acid derivative (C), the number of carbon atoms in the long-chain hydrocarbon group of the derivative is chlorinated polyolefin (A), ethylene vinyl acetate copolymer (B1) and/or chlorinated ethylene vinyl acetate copolymer. It preferably has 12 or more carbon atoms because it has good compatibility with coalescence (B2), has low crystallinity, and has good solubility in the solvent used.
Examples of fatty acids having 12 or more carbon atoms include lauric acid, myristic acid, pentadecyl acid, palmitic acid, palmitoleic acid, margaric acid, stearic acid, oleic acid, vaccenic acid, linoleic acid, linolenic acid, and arachidic acid. be done. These can also be used individually and can also use two or more types together.
Among them, lauric acid and oleic acid are preferred.

The fatty acid salt is a salt of the fatty acid with an inorganic or organic cation, and examples of counter ions constituting the salt include alkali metal ions such as potassium ion and sodium ion, alkaline earth metal ions, and ammonium ion. be done. Specific examples include sodium stearate, potassium stearate, sodium oleate, sodium palmitate, and ammonium stearate.

The fatty acid ester used in the present invention is an ester compound of the above fatty acid and an alcohol of any valence. Monohydric alcohols for obtaining the fatty acid ester used in the present invention include methanol, ethanol, 1-propanol, 1-butanol, 2-methyl-1-propanol, 2-butanol, 2-methyl-2-propanol, 1 - linear and branched saturated such as heptanol, 3-methyl-1-butanol, 2-pentanol, 1-hexanol, 2-hexanol, 1-heptanol, 2-heptanol, 1-octanol, 2-ethyl-1-hexanol Alcohol can be used singly or in combination.
Dihydric alcohols for obtaining fatty acid esters used in the present invention include, for example, ethylene glycol, 1,2-propylene glycol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, Aliphatic diols such as diethylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol and neopentyl glycol; bisphenols such as bisphenol A, bisphenol S and bisphenol F; polyalkylene oxide adducts of bisphenol A; polyalkylene oxides of bisphenol S adducts, aromatic diols such as bisphenol derivatives such as alkylene oxide adducts of bisphenol such as polyalkylene oxide adducts of bisphenol F; alicyclic diols such as cyclohexanedimethanol;
Examples of trihydric or higher alcohols for obtaining the fatty acid ester used in the present invention include glycerin, trimethylolethane, trimethylolpropane, sorbitol, 1,2,3,6-hexanetetrol, 1,4 -sorbitan, pentaerythritol, dipentaerythritol, 2-methylpropanetriol, 1,3,5-trihydroxybenzene, tris(2-hydroxyethyl)isocyanurate and the like.

The fatty acid ester includes "a fatty oil that is liquid at room temperature of 25°C among oils and fats that are esters of fatty acids".
Fatty oils include salad oil, refined oil, corn oil, soybean oil, sesame oil, rapeseed oil (canola oil), kaya oil, rice bran oil, bran oil, camellia oil, safflower oil (safflower oil), and coconut oil (palm kernel oil). , cottonseed oil, sunflower oil, perilla oil, linseed oil, olive oil, peanut oil, almond oil, avocado oil, hazelnut oil, walnut oil, grape cider oil, mustard oil, vegetable oils such as lettuce oil, whale oil, shark oil, liver oil and other fish oils. Among them, soybean oil is preferred.

Epoxidized fatty oils such as epoxidized soybean oil, epoxidized linseed oil, epoxidized fatty acid octyl ester, and epoxidized fatty acid alkyl ester may also be used. Among them, epoxidized soybean oil is preferred.

Moreover, castor oil etc. can be mentioned as an industrial fatty oil. Castor oil extracted from the seeds of the castor bean plant (castor) can be mentioned, and this castor oil is hydrogenated to make it difficult to oxidize, and hydrogenated castor oil obtained by addition polymerization of petroleum-derived ethylene oxide. It can also be used.

Examples of fatty acid amines include fatty acid primary amines such as octanoic acid amine, laurylamine, stearylamine, oleylamine and behenylamine, octanoic acid monomethylamine, laurylmonomethylamine, stearylmonomethylamine, stearylmonoethylamine, stearylmonopropylamine, Fatty acid secondary amines such as oleylmonomethylamine and behenylmonomethylamine, dimethylamine octanoate, lauryldimethylamine, stearyldimethylamine, stearyldiethylamine, stearyldipropylamine, stearylethylmethylamine, oleyldimethylamine, behenyldimethylamine, etc. can be exemplified by fatty acid tertiary amines.

Typical examples of fatty acid amines include dimethylaminopropylamine structure as a pigment adsorption group, and amine-based fatty acid having a stearic acid-based fatty acid structure and a 12-hydroxystearic acid structure as a compatible group. It can be purchased as "Solsperse 17000" manufactured by Lubrizol.

In addition, a basic pigment dispersant in which castor oil-based ester and fatty oil are added to polyethylenimine and polycaprolactone to which fatty oil is added are also preferable as amine-based fatty acids and are commercially available. , can be purchased as "Solsperse 28000" manufactured by Lubrizol.

In the printing ink for laminate of the present invention, the fatty acid derivative (C) is preferably one or more compounds selected from the group consisting of fatty acids, fatty acid salts, fatty acid esters and fatty acid amines.

The printing ink for lamination of the present invention may contain a rosin-based resin for the purpose of improving the ink transferability seen in plate clogging. Furthermore, the ink stability is improved by containing the rosin-based resin when the methylcyclohexane solvent described later is not used.
Examples of the rosin-based resin include rosin, hydrogenated rosin, acid-modified rosin, and ester rosin.
Examples of the rosin include unmodified rosins such as tall oil rosin, gum rosin, and wood rosin containing resin acids such as abietic acid, levopimaric acid, palustric acid, neoabietic acid, dehydroabietic acid, and dihydroabietic acid as main components.
Hydrogenated rosins can be obtained by hydrogenating the unmodified rosins.
Examples of the acid-modified rosin include fumalopimaric acid obtained by adding fumaric acid to rosin by Diels-Alder addition reaction, and maleopimaric acid obtained by adding maleic acid.
Among the acid-modified rosins, maleic rosin is particularly preferred.
Examples of the esterified rosin include glycerin ester obtained by esterification reaction of rosin and glycerin, and pentaerythritol ester obtained by esterification with pentaerythritol.

The rosin-based resin preferably has an acid value of 150 to 250 mgKOH/g. If the acid value of the rosin-based resin is 150 mgKOH/g or more, it is possible to suppress the tendency of deteriorating the suitability for overprinting. tends to be easier. Also, the softening point of the rosin-based resin is preferably 100 to 170°C. If the softening point of the rosin-based resin is 100°C or higher, the tendency of the ink film to soften and the blocking property to decrease can be suppressed. and the storage stability of the ink tends to be maintained.

The organic solvent (D) used in the printing ink for laminate of the present invention is not particularly limited. , octane, and decane, and ester-based organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, n-propyl acetate, butyl acetate, amyl acetate, ethyl formate, and butyl propionate. Water-miscible organic solvents include alcohols such as methanol, ethanol, propanol, butanol and isopropyl alcohol, ketones such as acetone, methyl ethyl ketone and cyclohaxanone, ethylene glycol (mono, di) methyl ether, and ethylene glycol (mono, di) ethyl. Ether, ethylene glycol monopropyl ether, ethylene glycol monoisopropyl ether, monobutyl ether, diethylene glycol (mono, di) methyl ether, diethylene glycol (mono, di) ethyl ether, diethylene glycol monoisopropyl ether, diethylene glycol monobutyl ether, triethylene glycol (mono, Di)methyl ether, propylene glycol (mono, di)methyl ether, propylene glycol monopropyl ether, propylene glycol monobutyl ether, dipropylene glycol (mono, di)methyl ether, and other glycol ether organic solvents can be used. These can be used singly or in combination of two or more.

Among them, from the viewpoint of solubility in chlorinated polyolefin (A), ethylene vinyl acetate copolymer (B1), and chlorinated ethylene vinyl acetate copolymer (B2), a mixture of methylcyclohexane/cyclohexane/methyl ethyl ketone/ethyl acetate, Or toluene/cyclohexane/methyl ethyl ketone is more preferred. For drying adjustment, glycol ethers can be added as long as they are less than 10% by mass of the total amount of the composition.
It is more preferable not to use aromatic hydrocarbon solvents such as toluene and xylene from the standpoint of work hygiene during printing and harmfulness of packaging materials.
Furthermore, the use of hydrocarbon solvents such as methylcyclohexane and ethylcyclohexane is sometimes avoided from the viewpoint of odor. In this case, from the viewpoint of solubility and ink stability, it is preferable to use the chlorinated ethylene-vinyl acetate copolymer (B2) rather than the ethylene-vinyl acetate copolymer (B1).
The degree of chlorination is preferably in the range of 5-40. Within this range, the dispersibility of the pigment and the solubility in non-methylcyclohexane solvents are improved. Here, the degree of chlorination of the chlorinated ethylene-vinyl acetate copolymer (B2) in the present invention is mass % of chlorine atoms in the ethylene-vinyl acetate copolymer.

The pigment used in the printing ink for laminate of the present invention may be either a color pigment or a white pigment. If a white pigment is added, it can be used as a white ink corresponding to the background of a pattern, for example, in reverse gravure printing.

Examples of the coloring pigment used in the printing ink for laminate of the present invention include organic pigments and dyes used in general inks, paints, recording agents, and the like. Examples of organic pigments include azo, phthalocyanine, anthraquinone, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethineazo, ditopyrrolopyrrole, and isoindoline pigments. pigments.

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.

C.I. I. Pigment Blue 15:3 (copper phthalocyanine), yellow ink is C.I. I. Pigment Yellow 83, C.I. I. Pigment Red 57:1 is preferably used. It is preferable to use carbon black for black ink, aluminum for gold and silver inks, and mica for pearl ink from the viewpoint of cost and coloring power. Although aluminum is in the form of powder or paste, it is preferable to use it in the form of paste from the standpoint of handling and safety, and whether to use leafing or non-leafing is appropriately selected from the viewpoint of brightness and density.

Examples of white pigments used in the printing ink for laminate of the present invention include titanium oxide, zinc sulfide, lead white, zinc white, litbon, antimony white, basic lead sulfate, basic lead silicate, and barium sulfate. , calcium carbonate, gypsum, silica, and the like.
The average particle diameter of the pigment is preferably in the range of 10-400 nm, more preferably about 50-350 nm. The amount of the coloring pigment to be added is preferably in the range of 1 to 20% by mass based on the total amount of the ink in order to obtain sufficient image density and lightfastness of the printed image.

In the present invention, a combined resin, extender pigment, pigment dispersant, leveling agent, antifoaming agent, wax, plasticizer, infrared absorber, ultraviolet absorber, aromatic agent, flame retardant, etc. can also be included, if necessary. .

Examples of resins used in combination with the printing ink for laminate of the present invention as necessary include resins other than the chlorinated polyolefins, ethylene-vinyl acetate copolymers, and chlorinated ethylene-vinyl acetate copolymer rosins, such as polyurethane resins. , vinyl acetate resin, acrylic resin, polyester resin, alkyd resin, polyvinyl chloride resin, ketone resin, cyclized rubber, chlorinated rubber, butyral, and petroleum resin. The combined resin can be used alone or in combination of two or more. The content of the combined resin is preferably 1 to 25% by mass, more preferably 2 to 15% by mass, based on the total mass of the ink.

In order to stably disperse the pigment in the organic solvent, the resin alone can be dispersed, but a dispersant can also be used in combination to stably disperse the pigment. Anionic, nonionic, cationic, and amphoteric surfactants can be used as dispersants. For example, a comb-structure polymer compound obtained by adding polyester to polyethyleneimine, or an alkylamine derivative of an α-olefin maleic acid polymer may be used. Specific examples include Solspers series (LUBRIZOL), Ajisper series (Ajinomoto), Homogenol series (Kao), and the like. BYK series (BYK-Chemie), EFKA series (EFKA) and the like can also be used as appropriate. The dispersant is preferably contained in the ink in an amount of 0.05% by mass or more relative to the total mass of the ink from the viewpoint of ink storage stability, and 5% by mass or less from the viewpoint of lamination suitability, and more preferably 0. .1 to 2% by mass.

The printing ink for laminate of the present invention can be produced by dissolving and/or dispersing each resin, colorant, etc. in an organic solvent. Specifically, an ink can be produced by producing a pigment dispersion by dispersing a pigment in an organic solvent using each resin, and blending other compounds into the obtained pigment dispersion as necessary. can.

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 processing time, the ejection speed of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. As the dispersing machine, commonly used roller mills, ball mills, pebble mills, attritors, sand mills and the like can be used.
If air bubbles or unexpected coarse particles are contained in the ink, it is preferable to remove them by filtration or the like, as they reduce the quality of printed matter. A conventionally known filter can be used.

The viscosity of the ink produced by the above method is preferably in the range of 10 mPa·s or more from the viewpoint of preventing sedimentation of the pigment and appropriately dispersing the pigment, and in the range of 1000 mPa·s or less from the viewpoint of work efficiency during ink production and printing. preferable. The above viscosity is measured at 25° C. with a B-type viscometer manufactured by Tokimec.
The viscosity of the ink can be adjusted by appropriately selecting the types and amounts of raw materials used, such as resins, colorants, organic solvents, and the like. Also, the viscosity of the ink can be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

Polypropylene (PP) is mainly used as a plastic film that can be used as a substrate, but there is no particular limitation. Examples include polyamide resins such as nylon 6, nylon 66, and nylon 46, polyethylene phthalate (PET), Polyester resins such as polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyhydroxycarboxylic acids such as polylactic acid, poly(ethylene succinate), poly(butylene succinate) ) and other thermoplastic resins such as biodegradable resins such as aliphatic polyester resins, polyolefin resins such as polyethylene, polyimide resins, polyarylate resins, or mixtures thereof, and laminates thereof. Among them, films made of polyester, polyamide, polyethylene, and polypropylene can be preferably used.
These films may be either unstretched films or stretched films, and the manufacturing method thereof is not limited. Also, the thickness of the base film is not particularly limited, but it is usually in the range of 1 to 500 μm.
In addition, if the printed surface of the film is subjected to corona discharge treatment, the adhesiveness to the substrate can be further improved, which is preferable. Also, silica, alumina, or the like may be vapor-deposited.
As for the printing method, a printing method using a known plate such as gravure printing or flexographic printing can be used, but printing by the gravure printing method is particularly preferable. A well-known cylinder such as an engraving type or an etching type is used for gravure printing.

Further, the printing ink for lamination of the present invention may have a viscosity of 5 to 30 seconds at 25° C. in a Zahn cup #4 manufactured by Rigosha, more preferably 6 to 6 to 20 seconds, more preferably 8 to 18 seconds. Viscosity in millipascal seconds at 25° C. may be in the range of 50 to 400 (mPa s), more preferably in the range of 50 to 240 (mPa s), still more preferably It is in the range of 80 to 220 (mPa·s).
The viscosity when the base ink containing the above-mentioned continuous thickness is diluted and adjusted to a printing ink using a suitable mixed solvent is 60 to 100 (mPa) within a range of 13 to 18 seconds with Zahn cup #3 manufactured by Rigo Co., Ltd. at 25 ° C. · The range of s) is preferred.

EXAMPLES The present invention will be described more specifically with reference to Examples. Hereinafter, "parts" and "%" are based on mass.
The measurement of the weight average molecular weight (in terms of polystyrene) by GPC (gel permeation chromatography) in the present invention was carried out under the following conditions using an HLC8220 system manufactured by Tosoh Corporation.
Separation column: 4 TSKgelGMHHR-N manufactured by Tosoh Corporation are used. Column temperature: 40°C. Moving bed: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0 ml/min. Sample concentration: 1.0% by weight. Sample injection volume: 100 microliters. Detector: differential refractometer.
Viscosity was measured at 25° C. with a B-type viscometer manufactured by Tokimec.

(Preparation of resin solution of ethylene-vinyl acetate copolymer (B1))
As a resin solution of ethylene-vinyl acetate copolymer (B1), EVAFLEX EV40W manufactured by Mitsui-DuPont Polychemical Co.; A resin solution (B1L) was prepared by adding at a mass ratio of 40 and dissolving so as to have a solid content of 20%.

(Preparation of resin solution of chlorinated ethylene-vinyl acetate copolymer (B2))
As a resin solution of chlorinated ethylene-vinyl acetate copolymer (B2), CEVA B-3 (chlorination degree 30-40) manufactured by Senzhou Beipu Plastic Chemical Co., Ltd. was mixed with ethyl acetate/n-propyl acetate/methyl ethyl ketone = 20/20/40. was added at a mass ratio of , and dissolved to a solid content of 20% to prepare a resin solution (B2L).

(Adjustment of mixed solvent I)
Mixed solvent I was prepared by mixing n-propyl acetate/methyl ethyl ketone/methylcyclohexane at a mass ratio of 25/25/50, which is used in the kneading of the base ink and the preparation of the ink after kneading.

[Examples 1 to 12, Comparative Examples 1 to 8: Preparation of base ink mixture and ink]
First, the base ink to which the indigo pigment was added was kneaded using a Mighty Mill (manufactured by Inoue Seisakusho Co., Ltd.) at the blending ratio shown in Tables 1 to 3, and then the blending ratio shown in Tables 1 to 3 was used to prepare the printing ink. An indigo ink was prepared.

[Example 1]
10 parts of indigo pigment Fastogen Blue FA5380 (manufactured by DIC), 15 parts of resin solution (B1L) of ethylene-vinyl acetate copolymer (B1), 10 parts of resin solution (B2L) of chlorinated ethylene-vinyl acetate copolymer (B2), 15 parts of the mixed solution I was added and kneaded with a mighty mill to prepare a base ink.
Superchron SC360 (chlorination degree 31, solid content 60% (using ethyl alcohol solvent), CAS No. 68442-33-1, chlorinated polypropylene, manufactured by Nippon Paper Industries Co., Ltd.) is added to the base ink as a chlorinated polyolefin (A). 10 copies,
15 parts of resin solution (B2L) of chlorinated ethylene-vinyl acetate copolymer (B2), 24.5 parts of mixed solvent I, and 0.5 part of soybean oil as fatty acid derivative (C) were added and stirred to prepare indigo ink. .

[Example 2]
Instead of 0.5 parts of fatty acid derivative (C) soybean oil in Example 1, 0.5 parts of castor oil was added, and indigo ink was prepared in the same manner as in Example 1.

[Example 3]
Instead of 0.5 parts of fatty acid derivative (C) soybean oil in Example 1, 1.5 parts of lauric acid (having 12 carbon atoms) was added, and 23.5 parts of mixed solution I was added so that the total amount of ink was 100 parts. An indigo ink was prepared in the same manner as in Example 1, with adjustment made in the parts.

[Example 4]
Instead of 0.5 parts of fatty acid derivative (C) soybean oil in Example 1, 1.5 parts of oleic acid (having 18 carbon atoms) was added, and 23.5 parts of mixed solution I was added so that the total amount of ink was 100 parts. An indigo ink was prepared in the same manner as in Example 1, with adjustment made in the parts.

[Example 5]
Instead of 0.5 parts of fatty acid derivative (C) soybean oil in Example 1, 2.0 parts of epoxidized soybean oil (Eposizer W-100-EL, acid value 0.5 KOHmg/g, manufactured by DIC Corporation) was added. 23 parts of mixed solution I was adjusted so that the total amount of ink was 100 parts, and indigo ink was prepared in the same manner as in Example 1.

[Examples 6 to 9, 13 and 14]
For Examples 6 to 9, amine-based fatty acid Solsperse 17000 (solid content: 50%, manufactured by Lubrizol) was used as the fatty acid derivative (C). Solsperse 17000 is a single-type basic compound (quaternary ammonium salt of ω-dialkylamide) having a compatible group with a pigment-adsorbing group. with 12-hydroxystearic acid between both the pigment-adsorbing group and the compatibility group.
In Examples 13 and 14, an indigo ink was prepared by using amine fatty acid Solsperse 17000 together with soybean oil, which is another fatty acid derivative, and lauric acid.

[Example 10]
Instead of 0.5 parts of fatty acid derivative (C) soybean oil in Example 1, 3 parts of hydrogenated castor oil (T-20SF, manufactured by Ito Oil Co., Ltd.) was added, and 22 parts of mixed solution I was added so that the total amount of ink was 100 parts. An indigo ink was prepared in the same manner as in Example 1, with adjustment made in the parts.

[Examples 11 and 12]
For Examples 11 and 12, Solsperse 28000 (solid content: 50%, manufactured by Lubrizol) was used as the fatty acid derivative (C). Solsperse 28000 polyethylene is a basic pigment dispersant in which castor oil-based ester and fatty oil are added to imine, and fatty oil is added to polycaprolactone to form a comb-shaped skeleton.
In Example 12, 1 part of a rosin solution (Malquido No. 31, a maleated rosin manufactured by Arakawa Chemical Industries; acid value of 200 or less, dissolved in ethyl alcohol to a solid content of 50%) was added.

[Comparative Example 1]
In Comparative Example 1, an indigo ink was prepared according to the formulation shown in Table 3 and in the same manner as in Example 1 without using the fatty acid derivative (C).

[Comparative Example 2]
In Comparative Example 2, according to the formulation shown in Table 3, the fatty acid derivative (C) was not used in the same procedure as in Example 1, and a rosin solution (Malquedo No. 31, which is a maleated rosin manufactured by Arakawa Chemical Industries, Ltd.; acid 200 or less, dissolved in ethyl alcohol to a solid content of 50%), and mixed solution I was adjusted to 20 parts so that the total amount of ink was 100 parts. Indigo ink was prepared by

[Comparative Example 3]
In Comparative Example 3, soybean oil, which is the fatty acid derivative (C), was added to 0.05 parts, mixed solution I was adjusted so that the total amount of ink was 100 parts, and an indigo ink was prepared in the same manner as in Example 1. did.

[Comparative Example 4]
In Comparative Example 4, 12 parts of soybean oil, which is the fatty acid derivative (C), was adjusted to 15 parts of mixed solution I so that the total amount of ink was 100 parts. made.

[Comparative Example 5]
In Comparative Example 5, 0.05 part of amine-based fatty acid Solsperse 17000 (manufactured by Lubrizol), which is the fatty acid derivative (C), was used to adjust the mixed solution I so that the total amount of the ink was 100 parts. An indigo ink was prepared by the same procedure.

[Comparative Example 6]
In Comparative Example 6, 12 parts of amine-based fatty acid Solsperse 17000 (manufactured by Lubrizol), which is the fatty acid derivative (C), was adjusted to 15 parts of mixed solution I so that the total amount of ink was 100 parts. Indigo ink was prepared in the same procedure as.

[Comparative Example 7]
In Comparative Example 7, 0.05 part of Solsperse 28000 (manufactured by Lubrizol), which is the fatty acid derivative (C), was used to adjust the mixed solution I so that the total amount of the ink was 100 parts. to prepare an indigo ink.

[Comparative Example 8]
In Comparative Example 8, 12 parts of Solsperse 28000 (manufactured by Lubrizol), which is a fatty acid derivative (C), was adjusted to 15 parts of mixed solution I so that the total amount of ink was 100 parts. Indigo ink was prepared according to the procedure.

Using the prepared indigo inks of Examples 1 to 12 and Comparative Examples 1 to 8, evaluation tests were conducted according to the following procedure.

[Evaluation item 1: Adhesion to film]
The viscosity of the indigo ink shown in Tables 1 to 3 was adjusted to 16 seconds (25 ° C.) with the mixed solvent I using Zahn Cup #3 (manufactured by Rigosha), and a gravure proofing machine equipped with a plate depth of 22 μm gravure plate was used. , Printed on the corona-treated side of biaxially oriented polypropylene film V (hereinafter referred to as OPP film, P2161 manufactured by Toyobo Co., Ltd., thickness 20 μm). Width) was affixed and rapidly peeled off, and the external appearance of the printed film was visually evaluated according to the following five grades.

5: The printed film was not peeled off at all.
4: 70% or more to less than 90% of the printed film remained on the film.
3: 50% or more to less than 70% of the printed film remained on the film.
2: 30% or more to less than 50% of the printed film remained on the film.
1: Only less than 30% of the print film remained.

[Evaluation Item 2: Metastatic]
The indigo inks shown in Tables 1 to 3 were diluted with the mixed solvent I using Zahn Cup No. 3 manufactured by Rigosha Co., Ltd. so that the time was 16 seconds. Using an MD type gravure printing machine (manufactured by Fuji Kikai Co., Ltd.) equipped with a laser gravure plate having a plate depth of 25 μm, a biaxially oriented polypropylene film V (manufactured by Toyobo Co., Ltd.) was subjected to corona discharge treatment on one side. P2161 20 μm thick) was printed on the treated side.
The transferability is evaluated by a blurring test to evaluate the ratio of the area of blurring in the highlight printed part (halftone dot area less than 10%) when the circumference of the gravure plate is 600mmφ and the printing speed is 200m/min, and the staining of the non-printing part. The condition was visually evaluated. An evaluation of 4 or higher is within the practical range.
(Evaluation criteria)
5: There is no fading and no smearing in the non-printed area.
4: Slight blurring is observed, or stains are slightly observed in the non-printed area.
3: Slight blurring is observed, and stains are slightly observed in the non-printed area.
2: Blurs are observed, and stains are observed in the non-printed area.
1: A large amount of faintness is observed, and a large amount of stain is also observed in the non-printed area.

[Evaluation item 3: lamination strength]
An ether-based dry lamination adhesive Dick Dry LX-401A/SP-60 (manufactured by DIC) was applied to the printed matter so that the coating amount was ^2.5 g/m Office) to laminate an unstretched polypropylene film (hereinafter referred to as CPP: P1128 20 μm manufactured by Toyobo Co., Ltd.) and aged at 40 ° C. for 3 days to obtain a laminate, then cut into a width of 15 mm and pulled at a speed of 300 mm / min. A 90 degree peel test was performed at
The larger the numerical value, the higher the lamination strength.

Tables 1 to 3 show the formulation of each indigo ink and the evaluation results.

From the above results, the laminate printing ink of the present invention was excellent in film adhesion and transferability, and the resulting printed matter had lamination strength.

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

Claims (3)

Printing containing chlorinated polyolefin (A), ethylene vinyl acetate copolymer (B1) and/or chlorinated ethylene vinyl acetate copolymer (B2), fatty acid derivative (C), and organic solvent (D) An ink composition comprising:
A printing ink for lamination, wherein the total amount of the fatty acid derivative (C) is 0.1 to 5% by mass based on the total amount of the ink.
However, the number of carbon atoms of the long-chain hydrocarbon group of the fatty acid derivative (C) is 12 or more, and the fatty acid derivative (C) is one or more selected from the group consisting of fatty acid salts, fatty acid esters, and fatty acid amines. is a compound.
The printing ink for laminate according to claim 1 , wherein the organic solvent (D) does not contain an aromatic hydrocarbon solvent.
A printed material obtained by printing the printing ink for lamination according to claim 1 or 2 on a plastic film using a gravure printing machine.