JP7073696B2 - Liquid ink composition - Google Patents

Description

The present invention relates to a gravure ink for laminating for flexible packaging and a liquid ink composition for flexographic ink. In particular, the present invention relates to a liquid ink composition for various films coated with a polypropylene film or an inorganic or organic barrier coating material, which tends to have poor adhesion.

A urethane resin or a urethane urea resin is mainly used as a main component in a liquid ink for laminating used in the production of flexible packaging materials.
Then, these urethane resins or urethane urea resins are manufactured using various reaction raw materials in order to have their respective characteristics.
For example, a printing ink for laminating in which a polyurethane polyurea resin soluble in an organic solvent obtained by reacting a polymer diol, an organic diisocyanate and a diamine as a chain extender is used as a main binder resin is exemplified (for example, Patent Document). 1).
Further, in a polyurethane resin obtained from a polymer diol and an organic diisocyanate, a vehicle for printing ink or a printing ink using a polyester polyol obtained from 3-methyl-1,5-pentanediol and dibasic acid as a polymer diol compound. Examples of the binder are given (for example, Patent Documents 2 to 4).
Further, an example of a binder using a polyurethane resin obtained by reacting a polyester polyol obtained by polycondensing 2-butyl-2-ethyl-1,3-propanediol with a polycarboxylic acid with a polyisocyanate is shown. (For example, Patent Documents 5 and 6).
Further, an example is made of a printing ink composition for laminating, which employs a polyester diol obtained from 2,4-diethyl-1,5-pentanediol, a polyester diol obtained from a dicarboxylic acid, and a polyurethane resin obtained from an organic diisocyanate compound (for example,). Patent Document 7).

Further, in recent years, the use of aromatic solvents such as toluene and ketone solvents such as methyl ethyl ketone have been restricted from the viewpoints of both work hygiene during printing and harmfulness of packaging materials. For example, for de-aromatic solvents and ketone solvent type liquid inks, from the viewpoint of printability, aromatics as solvents, acetate esters such as ethyl acetate and propyl acetate instead of ketone solvents, isopropyl alcohol and normal Alcohol-based solvents such as propyl alcohol or mixed solvents thereof tend to be used.

Various films such as polyethylene terephthalate, polypropylene, and nylon are used for the production of flexible packaging materials, and printing inks are required to have adhesion to these various printing substrates.
In particular, the adhesion is often insufficient for polypropylene films.
On the other hand, in recent years, as films used for film packages, high-performance films having various barrier properties have tended to increase. An inorganic or organic barrier coating agent is applied to the surface of these high-performance films, and when gravure printing or flexographic printing is performed using these high-performance films as raw fabrics, the adhesion between the raw fabrics and the ink is impaired. It can often happen that it is done. These high-performance films exist in a wide variety of applications for foods and electronic parts, such as oxygen barriers that block air to prevent deterioration of the contents and water vapor barriers that block water vapor, depending on the type of industry and application. In addition, many of them are technically undisclosed, and it is difficult to maintain adhesion compared to general film printing.

Even if the urethane resin made from the various reaction raw materials described above is used, it is not easy to maintain the adhesive strength uniformly to a wide variety of films that are increasing.

JP-A No. 55-25453 Japanese Patent Application Laid-Open No. 61-26680 JP-A-63-161065 Japanese Patent Application Laid-Open No. 63-317562 Japanese Patent Application Laid-Open No. 5-222333 JP-A-6-41264 Japanese Patent Application Laid-Open No. 2000-273382

The present invention can be applied to a wide variety of films, and is particularly excellent in adhesiveness and blocking resistance on various high-performance barrier films, and has high lamination strength before and after hot water treatment in an aluminum-structured packaging material. It is an object of the present invention to provide a liquid ink composition having excellent retort resistance.

As a result of intensive research to solve the above-mentioned problems, the present inventors have found that it is effective to solve the problems by adopting a polyurethane resin containing polycaprolactone diol as a reaction raw material in the liquid ink composition. I found.

That is, the present invention relates to a liquid ink composition characterized by containing a polyurethane resin (A) containing polycaprolactone diol as a reaction raw material.

Furthermore, the present invention relates to a liquid ink composition containing a vinyl chloride vinyl acetate copolymer resin (B) and / or nitrocellulose cotton (C).

Furthermore, the present invention relates to a liquid ink composition containing a colorant (D) and an organic solvent (E).

Further, the present invention relates to a liquid ink composition in which the content ratio of the polycaprolactone diol is in the range of 5 to 90 parts by mass with respect to 100 parts by mass of the diol which is the reaction raw material of the polyurethane resin (A).

Further, in the present invention, the vinyl chloride vinyl acetate copolymer resin (B) has a hydroxyl value, the hydroxyl value is 50 to 200 mg equivalent KOH / g, and the vinyl chloride component in the copolymer resin. The present invention relates to a liquid ink composition having a content ratio of 80 to 95 parts by mass.

Furthermore, the present invention relates to a liquid ink composition in which the organic solvent (E) does not contain an aromatic organic solvent and / or a ketone solvent.

Further, the present invention relates to a liquid ink composition having a number average molecular weight of 100 to 6000 of the polycaprolactone diol.

Furthermore, the present invention relates to a printed matter obtained by printing the liquid ink composition.

Furthermore, the present invention relates to a laminated laminate made of the printed matter.

INDUSTRIAL APPLICABILITY According to the present invention, it can be applied to a wide variety of films, particularly excellent in adhesiveness and blocking resistance on various high-performance barrier films, and high laminating strength before and after hot water treatment in an aluminum-structured packaging material. A liquid ink composition having excellent retort resistance can be obtained.

The present invention will be described in detail. The "inks" used in the following description all refer to "printing inks". Further, "part" and "%" all indicate "parts by mass" and "% by mass".

The liquid ink composition of the present invention is essential to contain a polyurethane resin (A) containing polycaprolactone diol as a reaction raw material.

Generally, in order to obtain a polyurethane resin, conventionally known materials such as a polyether type and / or a polyester type diol compound (number average molecular weight of 1,000 to 4,000), a diisocyanate compound and a chain extender, and a reaction terminator are used. And method.
Typical examples of the polyester type diol include polyethylene glycol, polypropylene glycol, polyoxytetramethylene glycol and the like, while typical examples of the polyester type diol are dibasic acids such as adipic acid, phthalic anhydride and isophthalic acid. Examples thereof include a condensate of ethylene glycol, propylene glycol, 1,4-butanediol, and glycols such as neopentyl glycol and / or polycaprolactone diol.
The polyurethane resin (A) used in the liquid ink composition of the present invention is a polyester diol using the latter polycaprolactone diol as a reaction raw material.
Examples of the polycaprolactone diol include ethylene glycol, polyethylene glycol, propylene glycol, polypropylene glycol, tetramethylene glycol, polytetramethylene glycol, 1,2-polybutylene glycol, 1,6-hexanediol, neopentyl glycol, and 1 Any polycaprolactone diol obtained by reacting a diol such as 4-cyclohexanedimethanol or 1,4-butanediol with ε-caprolactone may be used.

The content ratio of the polycaprolactone diol is preferably 5 to 90 parts by mass, more preferably 20 to 80 parts by mass with respect to 100 parts by mass of the diol which is the reaction raw material of the polyurethane resin (A). When it is 10 parts by mass or more and 90 parts by mass or less, the adhesion on the transparent vapor-filmed film, the blocking resistance, and the laminating strength in the laminated film structure containing aluminum in the base material become excellent.

The number average molecular weight of the polycaprolactone diol is preferably 100 to 6000, more preferably 400 to 5000.
When the number average molecular weight is 100 or more and 6000 or less, the laminating strength in the AL structure tends to be particularly excellent.

As the combined polyol used as necessary for the polyurethane resin (A) used in the liquid ink composition of the present invention, various known polyols generally used for producing a polyurethane resin can be used, and one kind is used. Alternatively, two or more types may be used in combination. For example, polyether polyols of polymers or copolymers such as methylene oxide, ethylene oxide, and tetrahydrofuran (1); ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2methyl-1,3propane. Diol, 2ethyl-2butyl-1,3 propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexanediol, octanediol , 1,4-Butindiol, 1,4-butylenediol, Diethylene glycol, Triethylene glycol, Dipropylene glycol, Glycerin, Trimethylolpropane, Trimethylolethane, 1,2,6-Hexanetriol, 1,2,4- Saturated or unsaturated low molecular weight polyols (2) such as butanetriol, sorbitol, pentaesritol; these low molecular weight polyols (2) and adipic acid, phthalic acid, isophthalic acid, terephthalic acid, maleic acid, Polyvalent carboxylic acids such as fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelli acid, speric acid, azelaic acid, sebacic acid, trimellitic acid, pyromellitic acid, or dehydration-condensation of these anhydrides. Polyester polyols obtained by polymerization (3); Polyester polyols obtained by ring-opening polymerization of cyclic ester compounds such as lactones such as polycaprolactone, polyvalerolactone and poly (β-methyl-γ-valerolactone). Class (4); Polycarbonate polyols (5) obtained by reacting the low molecular weight polyols (2) and the like with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgen and the like; polybutadiene glycols (6); bisphenol A. Glycols (7) obtained by adding ethylene oxide or propylene oxide to one molecule; with one or more hydroxyethyls, hydroxyprople acrylates, acrylic hydroxybutyls, etc., or their corresponding methacrylate derivatives, etc. Examples thereof include an acrylic polyol (8) obtained by copolymerizing with acrylic acid, methacrylic acid or an ester thereof.

Among the polyester polyols (3), the high molecular weight diol obtained from the diols (glycols) and the dibasic acid is a low molecule having up to 5 mol% of the diols having three or more hydroxyl groups. It can be replaced with polyols (2).

As the diisocyanate compound used in the polyurethane resin (A) in the laminating ink composition for flexible packaging of the present invention, various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic groups generally used for producing polyurethane resins are used. Examples include diisocyanate. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzylisocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3- Phenylene diisocyanate, 1,4-phenylenedi isocyanate, 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, Isophoron diisocyanate, Dimeryl diisocyanate, Dicyclohexylmethane-4,4'-Diisocyanate, 1,3-bis (isocyanatemethyl) cyclohexane, Methylcyclohexanediisocyanate, Norbornan diisocyanate, m-tetramethylxylylene diisocyanate Examples thereof include isocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, and dimerized isocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group. These diisocyanate compounds can be used alone or in admixture of two or more.

Examples of the chain extender used in the polyurethane resin (A) in the liquid ink composition of the present invention include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, and dicyclohexylmethane-4,4'-diamine. 2-Hydroxyethylethylenediamine, 2-hydroxyethylpropyldiamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2- Amines having a hydroxyl group in the molecule, such as hydroxypyrropyrethylenediamine, di-2-hydroxypyrropyrethylenediamine, and di-2-hydroxypropylethylenediamine, can also be used. These chain extenders can be used alone or in admixture of two or more.
Further, 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 gyn-butylamine and alcohols such as ethanol and isopropyl alcohol. Further, especially when it is desired to introduce a carboxyl group into the polyurethane resin, amino acids such as glycine and L-alanine can be used as a reaction terminator. These terminal blockers can be used alone or in admixture of two or more.

The polyurethane resin (A) in the liquid ink composition of the present invention can be obtained, for example, by reacting a polycaprolactone diol and a combined polyol with a diisocyanate compound at a ratio of an excess of isocyanate groups to obtain a prepolymer having a terminal isocyanate group. The prepolymer is placed in a suitable solvent, that is, an ester solvent such as ethyl acetate, propyl acetate, butyl acetate, which is usually used as a solvent for gravure ink; a ketone solvent such as acetone, methyl ethyl ketone, methyl isobutyl ketone; methanol, Alcohol-based solvents such as ethanol, isopropyl alcohol, n-butanol; hydrocarbon-based solvents such as toluene, xylene, methylcyclohexane, ethylcyclohexane; or mixed solvents thereof with chain extenders and / or terminal blockers. It is produced by a two-step method of reacting, or a one-step method of reacting polypropylene glycol and a combined polyol, a diisocyanate compound, a chain extender and / or a terminal sequestering agent at one time in a suitable solvent among the above. Among these methods, in order to obtain a uniform polyurethane resin, the two-step method is preferable. When the polyurethane resin is produced by the two-step method, the reaction is carried out so that the total (equivalent ratio) of the amino groups of the chain extender and / or the terminal blocker is 1 / 0.9 to 1.3. Is preferable. When the equivalent ratio of isocyanate group to amino group is less than 1 / 1.3, the chain extender and / or terminal blocker remain unreacted, the polyurethane resin turns yellow, and the odor after printing is generated. It may occur. Further, in recent years, from the viewpoint of the working environment, it is more preferable not to use an aromatic solvent such as toluene or xylene or a ketone solvent.

The weight average molecular weight of the polyurethane resin (A) thus obtained is preferably in the range of 15,000 to 100,000, more preferably in the range of 15,000 to 80,000. When the weight average molecular weight of the polyurethane resin is less than 15,000, the blocking resistance, the strength of the printed film, the oil resistance, etc. of the obtained ink composition tend to be low, and when it exceeds 100,000, the weight average molecular weight tends to be low. , The viscosity of the obtained ink composition tends to be high, and the gloss of the printing film tends to be low.
The content of the polyurethane resin (A) used in the liquid ink composition of the present invention in the ink is appropriately 4% by mass or more with respect to the total mass of the ink from the viewpoint of sufficiently adhering the ink to the printed matter. From the viewpoint of ink viscosity and work efficiency during ink production / printing, it is preferably 25% by mass or less, and more preferably 6 to 15% by mass.

Further, in the liquid ink composition of the present invention, vinyl chloride vinyl acetate copolymer resin (B) and / or nitrocellulose cotton (C) may be added.
By adding the vinyl chloride vinyl acetate copolymer resin (B), blocking resistance and retort resistance are improved. In particular, when the vinyl chloride vinyl acetate copolymer resin (B) contains a hydroxyl group, heat resistance such as retort resistance is significantly improved.

The vinyl chloride vinyl acetate copolymer resin (B) having a hydroxyl group has a hydroxyl value of 50 to 200 mgKOH / g, and the content ratio of the vinyl chloride component in the copolymer resin is 80 to 95% by mass. Things are preferable.

The vinyl chloride vinyl acetate copolymer resin (B) having a hydroxyl group used in the liquid ink composition of the present invention can be obtained by two kinds of methods. One is obtained by copolymerizing a vinyl chloride monomer, a vinyl acetate monomer and a vinyl alcohol in an appropriate ratio. The other is obtained by copolymerizing vinyl chloride and vinyl acetate and then partially saponifying the vinyl acetate. In the vinyl chloride vinyl acetate copolymer resin having a hydroxyl group, the properties of the resin film and the resin dissolving behavior are determined by the monomer ratios of vinyl chloride, vinyl acetate and vinyl alcohol. That is, vinyl chloride imparts toughness and hardness of the resin film, vinyl acetate imparts adhesiveness and flexibility, and vinyl alcohol imparts good solubility in polar solvents.

When liquid ink is used as a laminating ink for flexible packaging, it is necessary to satisfy all of these performances such as adhesiveness, blocking resistance, laminating strength, boil retort suitability, and printability. Therefore, vinyl chloride vinyl acetate copolymerization having a hydroxyl group The resin has an appropriate monomer ratio. That is, vinyl chloride is preferably 80 to 95 parts by mass with respect to 100 parts by mass of the vinyl chloride vinyl acetate copolymer resin having a hydroxyl group. If it is less than 80 parts by mass, the toughness of the resin coating tends to be inferior, and the blocking resistance tends to decrease. If it exceeds 95 parts by mass, the resin film becomes too hard and the adhesiveness tends to decrease. The hydroxyl value obtained from vinyl alcohol is preferably 50 to 200 mgKOH / g. If it is less than 50 mgKOH / g, the solubility in a polar solvent is inferior, and the printability tends to be poor. If it exceeds 200 mgKOH / g, the water resistance is lowered and the boil and retort suitability tends to be poor.

The vitrified cotton (C) (also referred to as nitrocellulose) used in the liquid ink composition of the present invention is suitable because it can obtain high dispersibility of the pigment and improve the heat resistance and oil resistance of the printing ink coating film. be.
The nitrocellulose used in the liquid ink composition of the present invention preferably has a nitrogen content of 10 to 13% by mass and an average degree of polymerization of 30 to 500, more preferably a nitrogen content of 10 to 13% by mass and an average degree of polymerization. It is 45 to 290. The amount of nitrocellulose added is preferably 0.05 to 10% by mass with respect to the solid content of the ink. More preferably, it is 0.1 to 3% by mass.

The colorant (D) used in the liquid ink composition of the present invention may be either a color pigment or a white pigment. If these pigments are not added, it can also be used as an overcoat varnish.

Examples of the colorant (D) used in the liquid ink composition 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 liquid ink composition 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. , Calcium carbonate, gypsum, silica, etc.
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.

As the organic solvent (E) used in the liquid ink composition of the present invention, various organic solvents can be used, for example, aromatic organic solvents such as toluene and xylene, and ketones such as acetone, methyl ethyl ketone and methyl isobutyl ketone. Examples include system solvents, ester solvents such as ethyl acetate, n-propyl acetate, butyl acetate and propylene glycol monomethyl ether acetate, and alcohol solvents such as n-propanol, inopropanol, n-butanol and propylene glycol monomethyl ether. Can be used alone or in admixture of two or more. In recent years, from the viewpoint of the working environment, it is more preferable not to use aromatic solvents such as toluene and xylene and ketone solvents.

Examples of the resin used in combination with the liquid ink composition of the present invention as needed include the polyurethane resin, vinyl chloride-vinyl acetate copolymer resin, and resins other than vitrified cotton, for example, chlorinated polypropylene resin and ethylene-. Vinyl acetate copolymer resin, vinyl acetate resin, polyamide resin, acrylic resin, polyester resin, alkyd resin, polyvinyl chloride resin, rosin resin, rosin-modified maleic acid resin, ketone resin, cyclized rubber, rubber chloride, butyral, Petroleum resin and the like can be mentioned. The combined resin can be used alone or in combination of two or more. The content of the combined resin is preferably 0.1 to 25% by mass, more preferably 2 to 15% by mass, based on the total mass of the ink.

The present invention may further include a combined resin, extender pigment, pigment dispersant, leveling agent, defoaming agent, wax, plasticizer, infrared absorber, ultraviolet absorber, fragrance agent, flame retardant and the like, if necessary. ..

Specifically, in the liquid ink composition of the present invention, the polyurethane resin, vinyl chloride vinyl acetate copolymer resin and / or nitrified cotton are premixed with various organic solvents such as ethyl acetate, methyl ethyl ketone, toluene and IPA. In the case of a varnish composition, the varnish composition can be obtained by adding various additives while stirring the solution with a dispersion stirrer and further stirring. In the case of an ink composition, an ink composition is obtained by adding a colorant and sufficiently dispersing the ink composition.

When the colorant (D) is used in the liquid ink composition of the present invention, the hue may be yellow, red, indigo, ink, or white depending on the type of the colorant (D) used. There are 5 colors, and there are 3 colors of red (orange), grass (green), and purple as the outer colors of the process gamat. Furthermore, transparent yellow, peony, vermilion, brown, gold, silver, pearl, and almost transparent medium for adjusting the color density (including extender pigment if necessary) are prepared as base colors. The ink for boil retort is appropriately selected in consideration of the migration property and heat resistance of the pigment. The base ink of each hue is diluted with a diluting solvent to a viscosity and concentration suitable for gravure printing or flexographic printing, and is supplied to each printing unit alone or mixed.

The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the crushed media of the disperser, the filling rate of the crushed media, the dispersion treatment time, the discharge rate of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. As the 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.
If the ink contains air bubbles or unexpectedly coarse particles, it is preferable to remove them by filtration or the like in order to deteriorate the quality of the printed matter. As the filter, a conventionally known one can be used.

The viscosity of the ink produced by the above method may be in the range of 10 mPa · s or more from the viewpoint of preventing the pigment from settling and appropriately dispersing, and 1000 mPa · s or less from the viewpoint of workability efficiency during ink production and printing. preferable. The viscosity is a viscosity measured at 25 ° C. with a B-type viscometer manufactured by Tokimec.
The viscosity of the ink can be adjusted by appropriately selecting the type and amount of the raw material used, for example, a polyurethane resin, a colorant, an organic solvent, and the like. Further, the viscosity of the ink can be adjusted by adjusting the particle size and the particle size distribution of the pigment in the ink.

As the plastic film that can be used, a polyester resin film is particularly preferable, while the liquid ink composition of the present invention is particularly useful for a polypropylene film that tends to have poor adhesion, and other polypropylene, nylon, and polyethylene resin films. It can also be widely used for various high-performance films in which an inorganic or organic barrier coating material is applied to the surface of the film.

The present invention will be described in more detail with reference to Examples. Hereinafter, both "part" and "%" are based on the mass standard.
The weight average molecular weight (in terms of polystyrene) and the number average molecular weight (in terms of polystyrene) in the present invention were measured by GPC (gel permeation chromatography) using the HLC8220 system manufactured by Toso Co., Ltd. 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 weight. Sample injection volume: 100 microliters. Detector: Differential refractometer.
The viscosity was measured at 25 ° C. with a Tokimec B-type viscometer.

[Synthesis Example 1]: Synthesis of polyurethane resin solution A1 using polycaprolactone diol / polyester polyol = 10/90 (mass ratio) In a four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube. 90.0 parts (hydroxyl value: 110.0 mgKOH / g) of polyester polyol composed of neopentyl glycol and adipic acid, 10.0 parts of polycaprolactone diol (hydroxyl value: 550.0 mgKOH / g) and 28.1 parts of hexamethylene diisocyanate. Was charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 1.99% by mass, and then 69.0 parts of ethyl acetate was added thereto to obtain a uniform solution of the urethane prepolymer. And said. Next, the urethane prepolymer solution was added to a mixture consisting of 5.14 parts of isophorondiamine, 0.58 parts of di-n-butylamine, 118.4 parts of ethyl acetate and 125.0 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution A1. The obtained polyurethane resin solution A1 had a resin solid content concentration of 30.2% by mass and a resin solid content Mw of 61,000.

[Synthesis Example 2]: Synthesis of polyester resin solution A2 using polycaprolactone diol / polyester polyol = 30/70 (mass ratio) In a four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube. 70.0 parts (hydroxyl value: 22.5 mgKOH / g) of polyester polyol consisting of neopentyl glycol, 2-methyl-1,3-propanediol and adipic acid and 30 parts of polycaprolactone diol (hydroxyl value: 220.0 mgKOH / g) ) And 26.0 parts of isophorone diisocyanate are charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 2.95% by mass, and then 67.8 parts of ethyl acetate is added thereto. In addition, a uniform solution of urethane prepolymer was prepared. Next, the urethane prepolymer solution was added to a mixture consisting of 7.87 parts of isophorondiamine, 0.15 parts of di-n-butylamine, 119.4 parts of ethyl acetate and 125.1 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution A2. The obtained polyurethane resin solution A2 had a resin solid content concentration of 30.0% by mass and a resin solid content Mw of 75,000.

[Synthesis Example 3]: Synthesis of polyester resin solution A3 using polycaprolactone diol / polyester polyol = 50/50 (mass ratio) In a four-necked flask equipped with a stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube. 50.0 parts (hydroxyl value: 58.9 mgKOH / g) of polyester polyol composed of 2-methyl-1,3-propanediol and adipic acid, 50 parts of polycaprolactone diol (hydroxyl value: 52.0 mgKOH / g) and tolylene 11.8 parts of isocyanate is charged and reacted at 80 ° C. for 7 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 1.38% by mass, and then 60.2 parts of ethyl acetate is added to the urethane. A uniform solution of prepolymer was used. Next, the urethane prepolymer solution was added to a mixture consisting of 3.15 parts of isophorondiamine, 0.66 parts of di-n-butylamine, 101.6 parts of ethyl acetate and 107.9 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution A3. The obtained polyurethane resin solution A3 had a resin solid content concentration of 30.5% by mass and a resin solid content Mw of 52,000.

[Synthesis Example 4]: Synthesis of polyurethane resin solution A4 using polycaprolactone diol / polyester polyol = 90/10 (mass ratio) In a four-necked flask equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. 10.0 parts of polyester polyol (hydroxyl value: 37.4 mgKOH / g) consisting of 1,2-propanediol and adipic acid, 90 parts of polycaprolactone diol (hydroxyl value: 112.0 mgKOH / g) and 21.8 parts of isophorone diisocyanate. , 7.3 parts of tolylene diisocyanate was charged and reacted at 80 ° C. for 15 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 3.05% by mass, and then 69.5 parts of ethyl acetate was added thereto. In addition, a uniform solution of urethane prepolymer was prepared. Next, the urethane prepolymer solution was added to a mixture consisting of 8.10 parts of isophorondiamine, 0.55 parts of di-n-butylamine, 123.3 parts of ethyl acetate and 128.5 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution A4. The obtained polyurethane resin solution A4 had a resin solid content concentration of 30.0% by mass and a resin solid content Mw of 55,000.

[Synthesis Example 5]: Synthesis of polyurethane resin solution A5 using polycaprolactone diol / polyester polyol / polytetramethylene glycol (PTMG) = 35/60/5 A stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube were provided. In a four-necked flask, 60.0 parts (hydroxyl value: 18.0 mgKOH / g) of a polyester polyol composed of 3-methyl-1,5-pentanediol and adipic acid and 35 parts of a polycaprolactone diol (hydroxyl value: 18.7 mgKOH / g). g), 5 parts of polytetramethylene glycol (hydroxyl value: 110.0 mgKOH / g), 5.0 parts of isophorone diisocyanate and 4.1 parts of hexamethylene diisocyanate are charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to isocyanate. After producing a urethane prepolymer having a group content of 2.05% by mass, 58.7 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 4.69 parts of isophorondiamine, 0.30 parts of di-n-butylamine, 101.0 parts of ethyl acetate and 106.5 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution A5. The obtained polyurethane resin solution A5 had a resin solid content concentration of 29.9% by mass and a resin solid content Mw of 67,000.

[Synthesis Example 6]: Synthesis of polyurethane resin solution A6 using polycaprolactone diol / polyester polyol / polyethylene glycol (PEG) = 60/30/10 Four equipped with a stirrer, thermometer, recirculation cooler and nitrogen gas introduction tube. In the mouth flask, 60.0 parts (hydroxyl value: 54.4 mgKOH / g) of polyester polyol composed of neopentyl glycol and adipic acid, 30 parts of polycaprolactone diol (hydroxyl value: 112.2 mgKOH / g) and 10 parts of polyethylene glycol (hydroxyl value: 112.2 mgKOH / g). Hydroxyl value: 279.0 mgKOH / g) and 32.1 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 2.91% by mass. 71.1 parts of ethyl acetate was added to prepare a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 7.92 parts of isophorondiamine, 0.45 parts of di-n-butylamine, 125.6 parts of ethyl acetate and 131.1 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution A6. The obtained polyurethane resin solution A6 had a resin solid content concentration of 30.7% by mass and a resin solid content Mw of 62,000.

[Synthetic Comparative Example 1]: A synthetic stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube for a polyurethane resin solution H1 using polyester polyol / polyethylene glycol (PEG) = 80/20 were provided without using polycaprolactone diol. In a four-necked flask, 80.0 parts (hydroxyl value: 22.5 mgKOH / g) of polyester polyol composed of neopentyl glycol, 2-methyl-1,3-propanediol and adipic acid and 20 parts of polyethylene glycol (hydroxyl value:: 279.0 mgKOH / g) and 25.0 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 3.16% by mass, and then ethyl acetate was added thereto. 67.3 parts were added to make a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 8.06 parts of isophorondiamine, 0.54 parts of di-n-butylamine, 119.7 parts of ethyl acetate and 124.7 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution H1. The obtained polyurethane resin solution H1 had a resin solid content concentration of 30.4% by mass and a resin solid content Mw of 60,000.

[Synthetic Comparative Example 2]: A synthetic stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube for a polyurethane resin solution H2 using polyester polyol / polyethylene glycol (PEG) = 70/30 were provided without using polycaprolactone diol. In a four-mouthed flask, 70.0 parts of a polyester polyol (hydroxyl value: 37.4 mgKOH / g) and 30 parts of polypropylene glycol (hydroxyl value: 278.0 mgKOH / g) composed of 3-methyl-1,5-pentanediol and adipic acid. ) And 32.0 parts of isophorone diisocyanate are charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to produce a urethane prepolymer having an isocyanate group content of 2.96% by mass, and then 71.1 parts of ethyl acetate is added thereto. In addition, a uniform solution of urethane prepolymer was prepared. Next, the urethane prepolymer solution was added to a mixture consisting of 8.11 parts of isophorondiamine, 0.26 parts of di-n-butylamine, 125.5 parts of ethyl acetate and 131.0 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution H2. The obtained polyurethane resin solution H2 had a resin solid content concentration of 30.1% by mass and a resin solid content Mw of 79,000.

[Synthetic Comparative Example 3]: Neopentyl glycol in a four-mouthed flask equipped with a synthetic stirrer, a thermometer, a recirculation cooler, and a nitrogen gas introduction tube for a polyurethane resin solution H3 using only a polyester polyol without using a polycaprolactone diol. , 100.0 parts of a polyester polyol made of adipic acid (hydroxyl value: 56.1 mgKOH / g) and 16.7 parts of isophorone diisocyanate were charged and reacted at 90 ° C. for 10 hours under a nitrogen stream to have an isocyanate group content of 1.82. After producing a mass% urethane prepolymer, 62.8 parts of ethyl acetate was added thereto to prepare a uniform solution of the urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture consisting of 4.36 parts of isophorondiamine, 0.48 parts of di-n-butylamine, 107.3 parts of ethyl acetate and 113.4 parts of isopropyl alcohol, and 5 at 45 ° C. The reaction was stirred for a time to obtain a polyurethane resin solution H3. The obtained polyurethane resin solution H3 had a resin solid content concentration of 30.4% by mass and a resin solid content Mw of 59,000.

[Adjustment example 1: Preparation of vinyl chloride vinyl acetate copolymer resin solution V]
Vinyl chloride vinyl acetate copolymer resin having a hydroxyl group used in combination with a polyurethane resin (vinyl chloride / vinyl acetate / vinyl alcohol = 92/3/5, hydroxyl value (mgKOH) = 64 with a resin monomer composition of mass%) is acetic acid. A 15% solution was prepared with ethyl, and this was used as a vinyl chloride resin solution V.

[Adjustment example 2: Preparation of nitrocellulose solution N]
Industrial vitrified cotton H1 / 2 (nitrocellulose, solid content 30%, viscosity 9.0 to 14.9% at a solution concentration of 25.0% by JIS K-6703, manufactured by Taihei Chemical Products Co., Ltd.) in 37.5 parts , 62.5 parts of a mixed solution of isopropyl alcohol / ethyl acetate / normal propyl acetate / methyl cyclohexane (ratio of 25/25/13/10 by weight) was added and sufficiently mixed to prepare a nitrocellulose solution N.

[Example 1]
25 parts of polyurethane resin solution A (solid content 30.2%), 10 parts of vinyl chloride vinyl acetate copolymer resin solution G (solid content 15%), 35 parts of titanium oxide pigment JR-780 manufactured by Teika Co., Ltd., ethyl acetate A mixture consisting of 10 parts and 10 parts of isopropyl alcohol was kneaded using a dynomill (manufactured by Willy et Baccophenon), and 10 parts of ethyl acetate was further added to the obtained white kneaded meat base ink to make liquid white. I made an ink.

[Examples 2 to 7 and Comparative Examples 1 to 3]
Inks were prepared in the same manner as in Examples 1 to 7 according to the composition composition shown in Table 1 and Comparative Examples 1 to 3 according to the composition composition shown in Table 2.
In Example 7, a nitrocellulose solution N was used instead of the prepared vinyl chloride vinyl acetate copolymer resin solution V.
The viscosity of the obtained printing ink was adjusted to 16 seconds (25 ° C.) with Zahn Cup # 3 (manufactured by Rigo Co., Ltd.) with ethyl acetate, and a gravure calibrator equipped with a plate depth of 35 μm gravure plate was used to show Tables 1 and 2. Print on various barrier films (W, X, Y, Z) and corona-treated polyester film (hereinafter PET film: manufactured by Toyobo Co., Ltd., trade name Ester E5102, thickness 12 μm) and dry at 40 to 50 ° C. to print the printed matter. Obtained.
The obtained printed matter has adhesiveness to various barrier films, blocking resistance, and lamination strength in a PET film / aluminum / unstretched polypropylene film (hereinafter, R-CPP: ZK-75 50 μm manufactured by Toray Synthetic Film Co., Ltd.). The appearance after the retort treatment was evaluated and evaluated. The results are shown in Tables 1 and 2. The evaluation was performed by the following test method.

1) Adhesiveness (various barrier films)
After leaving the printed matter for one day, a cellophane tape (Nichiban 12 mm width) was attached to the printed surface, and the appearance state of the printed film when the printed matter was rapidly peeled off was visually judged. The criteria were as follows.
◯: The printing film did not peel off at all.
Δ: 50% or more and less than 80% of the area ratio of the printed film remained on the film.
X: Less than 50% of the area ratio of the printed film remained on the film.

2) Blocking resistance (various barrier films)
The films are overlapped so that the printed surface and the non-printed surface of the printed matter are in contact with each other, a load of 10 kgf / cm ² is applied, the ink is allowed to pass in an environment of 40 ° C. for 12 hours, and after taking out, the ink is transferred to the non-printed surface. The state of was visually evaluated in three stages.
◯: No transfer is observed when the amount of ink transferred to the non-printed surface is 0% Δ: Transfer is observed at a ratio of less than 20% area ratio ×: Transfer is observed at a ratio of 20% or more.

3) Measurement of Laminate Strength Apply the urethane-based dry laminate adhesive Dick Dry LX-500 / KW-75 (manufactured by DIC) to the PET film printed matter so that the coating amount is 3.5 g / m ² , and after drying. , Aluminum foil (hereinafter referred to as AL: aluminum foil C manufactured by Toyo Aluminum Industry Co., Ltd., 15 μm) was laminated by a dry laminating machine (manufactured by DIC Engineering) to obtain a two-layer laminate 1. Next, an adhesive was similarly applied onto the AL of the laminate 1, a non-stretched polypropylene film (hereinafter, R-CPP: ZK-75 50 μm manufactured by Toray Synthetic Film Co., Ltd.) was laminated, and aged at 40 ° C. for 5 days. A three-layer composite laminate 2 was obtained. After that, the laminate strength was measured. The larger the value, the stronger the laminating strength.

4) Retort resistance (appearance evaluation of laminated material after retort treatment)
The obtained laminate 2 was made into a pouch having a size of 120 mm × 120 mm, and 70 g of a simulated food containing vinegar, salad oil, and minced meat sauce in a weight ratio of 1: 1: 1 was filled and sealed as the contents. The prepared pouch was subjected to steam retort sterilization treatment at 135 ° C. for 30 minutes, and then the degree of peeling was evaluated in three stages.
◯: There is no peeling.
Δ: There is a small blister-like peeling.
X: There is peeling on the entire surface regardless of the size.

Tables 1 and 2 show the formulation of each liquid white ink and the evaluation results.

Barrier film to be evaluated W: Alumina vapor-deposited transparent PET film manufactured by Dai Nippon Printing Co., Ltd. IB-PET-PUB (thickness: 12 μm)
X: Silica-deposited transparent PET film manufactured by Mitsubishi Plastics Co., Ltd. Tech Barrier TX-R (thickness: 12 μm)
Y: Silica-deposited transparent PET film made by Oike Kogyo Co., Ltd. MOS-TEB (thickness: 12 μm)
Z: Toppan Printing Co., Ltd. Aluminum oxide thin-film transparent PET film GL-ARH (thickness: 12 μm)

OPP film to be evaluated U: Toyobo Co., Ltd. P2161 (thickness: 20 μm)

In the examples, the adhesiveness to the transparent thin-film film, the blocking resistance, and the laminating strength before and after the hot water treatment in the aluminum-structured packaging material were high, resulting in excellent retort resistance.

The liquid ink composition of the present invention can be widely applied to industrial products such as food packaging materials, sanitary products, cosmetics, and electronic parts.

Claims (8)

A combined polyol consisting of polycaprolactone diol obtained by reacting a reaction raw material composed of diol and ε-caprolactone and a polyester polyol which is a condensate of dibasic acid and glycols.
Contains a polyurethane resin (A) containing the above as a reaction raw material and an organic solvent (E).
The content ratio of the polycaprolactone diol is in the range of 60 to 90 parts by mass with respect to 100 parts by mass of the diol which is the reaction raw material of the polyurethane resin (A).
A liquid ink composition, wherein the organic solvent (E) does not contain a ketone solvent. The liquid ink composition according to claim 1, further comprising nitrylated cotton (C). The liquid ink composition according to claim 1 or 2, further comprising a colorant (D). Further, the vinyl chloride vinyl acetate copolymer resin (B) is contained, the vinyl chloride vinyl acetate copolymer resin (B) has a hydroxyl value, and the hydroxyl value is 50 to 200 mg equivalent KOH / g. The liquid ink composition according to any one of claims 1 to 3 , wherein the content ratio of the vinyl chloride component in the copolymer resin is 80 to 95 parts by mass. The liquid ink composition according to any one of claims 1 to 4 , wherein the organic solvent (E) does not contain an aromatic organic solvent. The liquid ink composition according to any one of claims 1 to 5 , wherein the polycaprolactone diol has a number average molecular weight of 100 to 6000. A printed matter obtained by printing the liquid ink composition according to any one of claims 1 to 6 . A laminated laminate having a printing layer obtained by printing the liquid ink composition according to any one of claims 1 to 6 .