JP2023077667A - Liquid printing ink, printed matter, and packaging material - Google Patents

Abstract

To provide printed matter and a laminate that have lamination strength during lamination processing and have excellent printability while using a film having high moisture-proofness.SOLUTION: Provided is printed matter that has a substrate and a printed layer provided on the substrate. The printed matter has, as the substrate, a polypropylene film having a water vapor transmission rate at a thickness of 25 μm of 3.0 g/m2-24 hours or less. The printed layer contains a urethane resin as a binder resin, and the ratio of vinyl chloride vinyl acetate copolymer to the total amount of the binder resin is 20 mass% or less.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a printed matter and a laminate using a liquid ink composition that can be used as a laminate gravure ink or flexographic ink for flexible packaging.

Gravure inks and flexographic inks are widely used for the purpose of imparting decorativeness and functionality to printed materials such as flexible packaging films and papers. When gravure or flexographic printing substrates are used as packaging materials, especially as soft packaging materials for food products and sanitary products, packaging products that come in contact with the contents to prevent contact with the contents. Surface printing is performed in which the design is printed only on the outside of the packaging material without printing on the back side, which is the side of the packaging material. In addition, reverse printing is performed on transparent films in applications such as beverage labels, integrated packaging, overwraps for cup noodles, and food packaging films.

When printing on a film base material or paper, the printing surface of the ink may be laminated. As the film substrate, OPP film, PET film, nylon film, polyethylene, etc. are used. It is required to have both dry lamination strength for thermocompression bonding with a material and extrusion lamination strength for laminating a thermoplastic resin melted and extruded into a film on a substrate.

Conventionally, printing inks containing polyurethane resins and vinyl chloride-vinyl acetate copolymer resins (hereinafter referred to as "PVC") as binders have been widely used for such laminates (see Patent Document 1). These resins are a combination of binders that can achieve both excellent dispersibility and high film physical properties. It is an indispensable ink raw material to achieve various physical properties.

JP-A-2000-86709

In recent years, among the films used for film packages, there is a tendency to increase the number of high-performance films imparted with various barrier properties, such as those with improved moisture resistance. When these high-performance films are subjected to gravure printing or flexographic printing using the conventionally used ink as they are, the lamination strength may be lowered. These high-performance films exist in a wide variety of industries and purposes, such as oxygen barriers that block out air and water vapor barriers that block water vapor to prevent deterioration of contents for food and electronic components. In addition, there are many undisclosed technical matters, and it is the current situation that it is difficult to deal with it compared to general film printing.

On the other hand, there is also a demand for high designability of printed matter, and the development of an ink that has both excellent laminating strength and printability even when using a high-performance film is required.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a printed matter and a laminate that use a film having high moisture resistance, have lamination strength in the case of lamination, and are excellent in printability.

As a result of intensive studies to solve the above-mentioned problems, the inventors of the present invention have found a printing liquid in which a vinyl chloride-vinyl acetate copolymer is blended at a certain ratio or less in a film base material having high moisture resistance. It was found that using ink is effective in solving the problem.

That is, the present invention has a base material and a printed layer provided on the base material, and as the base material, a polypropylene film having a water vapor transmission rate of 3.0 g/m ² ·24 hours or less at a thickness of 25 µm. The printed layer contains a urethane resin as a binder resin, and the vinyl chloride-vinyl acetate copolymer has a ratio of 20% by mass or less with respect to the total amount of the binder resin.

Further, the present invention has a base material and a printed layer provided on the base material, and as the base material, a polypropylene film having a water vapor transmission rate of 3.0 g/m ² ·24 hours or less at a thickness of 25 μm. and the printed layer contains a urethane resin as a binder resin, and is a laminate using a printed matter in which the ratio of the vinyl chloride-vinyl acetate copolymer to the total amount of the binder resin is 20% by mass or less.

ADVANTAGE OF THE INVENTION According to the present invention, a printed matter and a laminate having adhesive strength in the case of lamination and excellent printability can be obtained while using a film having high moisture resistance. Since the printed matter and laminate of the present invention have high moisture resistance, they can be used as a packaging material for food products, electronic parts, etc., which prevents deterioration of contents and has excellent design.

(Definition of words)
In the present invention, liquid printing ink refers to liquid ink, such as gravure ink or flexo ink, which is applied to a printing method using a printing plate, preferably gravure ink or flexo ink. Also, the liquid printing ink of the present invention does not contain an active energy curable component, i.e. it is a liquid ink non-reactive to active energy rays.

Note that "ink" used in the following description all means "printing ink". In addition, all "parts" indicate "mass parts", "ink total amount" indicates the total amount of ink containing all volatile components such as organic solvents, and "ink solid content total amount" refers to volatile components. indicates the total amount of non-volatile components only, excluding

The printed matter of the present invention contains a urethane resin as a binder resin, and has a printed layer in which the ratio of the vinyl chloride-vinyl acetate copolymer to the total amount of the binder resin is 20% by mass or less. First, the liquid ink composition forming the printed layer in the printed matter of the present invention will be described.

<Liquid ink composition>
The liquid ink composition for forming the print layer contains a coloring pigment, a binder resin, an organic solvent, water and various additives as necessary.

(polyurethane resin)
A liquid ink composition contains a urethane resin. The polyurethane resin is not particularly limited as long as it is a polyurethane resin obtained by reacting a polyol and a polyisocyanate. As the polyol, for example, various known polyols that are commonly used in the production of polyurethane resins can be used, and one or more of them may be used in combination. For example, polymeric or copolymeric polyether polyols (1) such as methylene oxide, ethylene oxide, tetrahydrofuran; ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3 -propanediol, 2-ethyl-2butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 3-methyl-1,5-pentanediol, hexane diol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1, Saturated or unsaturated low-molecular-weight polyols (2) such as 2,4-butanetriol, sorbitol, and pentaesritol; these low-molecular-weight polyols (2), sebacic acid, adipic acid, phthalic acid, and isophthalic acid Polycarboxylic acids such as acids, terephthalic acid, maleic acid, fumaric acid, succinic acid, oxalic acid, malonic acid, glutaric acid, pimelic acid, spelic acid, azelaic acid, trimellitic acid, pyromellitic acid, or anhydrides thereof Polyester polyols (3) obtained by dehydration condensation or polymerization of; Polyester polyols obtained by (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, phosgene, etc.; Polybutadiene glycols ( 6); Glycols obtained by adding ethylene oxide or propylene oxide to bisphenol A (7); One or more hydroxyethyl, hydroxypropyl acrylate, acrylhydroxybutyl, etc. per molecule, or their corresponding Acrylic polyol (8) obtained by copolymerizing a methacrylic acid derivative or the like with, for example, acrylic acid, methacrylic acid, or an ester thereof can be mentioned.

Examples of polyisocyanates include various known aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, and the like, which are generally used in the production of polyurethane resins. For example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 1-methyl-2,4-phenylene diisocyanate, 1-methyl-2,6-phenylene diisocyanate, 1-methyl-2,5-phenylene diisocyanate, 1 -methyl-2,6-phenylene diisocyanate, 1-methyl-3,5-phenylene diisocyanate, 1-ethyl-2,4-phenylene diisocyanate, 1-isopropyl-2,4-phenylene diisocyanate, 1,3-dimethyl-2 ,4-phenylene diisocyanate, 1,3-dimethyl-4,6-phenylene diisocyanate, 1,4-dimethyl-2,5-phenylene diisocyanate, diethylbenzene diisocyanate, diisopropylbenzene diisocyanate, 1-methyl-3,5-diethylbenzene diisocyanate, 3-methyl-1,5-diethylbenzene-2,4-diisocyanate, 1,3,5-triethylbenzene-2,4-diisocyanate, naphthalene-1,4-diisocyanate, naphthalene-1,5-diisocyanate, 1-methyl -naphthalene-1,5-diisocyanate, naphthalene-2,6-diisocyanate, naphthalene-2,7-diisocyanate, 1,1-dinaphthyl-2,2'-diisocyanate, biphenyl-2,4'-diisocyanate, biphenyl-4 ,4'-diisocyanate, 3-3'-dimethylbiphenyl-4,4'-diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,2'-diphenylmethane diisocyanate, diphenylmethane-2,4-diisocyanate and other aromatic polyisocyanates ; tetramethylene diisocyanate, hexamethylene diisocyanate, dodecamethylene diisocyanate, trimethylhexamethylene diisocyanate, 1,3-cyclopentylene diisocyanate, 1,3-cyclohexylene diisocyanate, 1,4-cyclohexylene diisocyanate, 1,3-di(isocyanate methyl)cyclohexane, 1,4-di(isocyanatomethyl)cyclohexane, lysine diisocyanate, isophorone diisocyanate, 4,4'-dicyclohexylmethane diisocyanate, 2,4'-dicyclohexylmethane diisocyanate, 2,2'-dicyclohexylmethane diisocyanate, 3, Aliphatic or alicyclic polyisocyanates such as 3'-dimethyl-4,4'-dicyclohexylmethane diisocyanate can be used. These polyisocyanates may be used alone or in combination of two or more. Among these, these diisocyanate compounds can be used alone or in combination of two or more.

A chain extender can also be used. Examples of chain extenders include ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4′-diamine, 2-hydroxyethylethylenediamine and 2-hydroxyethylpropyldiamine. , 2-hydroxyethylpropylenediamine, di-2-hydroxyethylethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyropyrethylenediamine, di-2-hydroxypyropyrethylenediamine, di- Amines having a hydroxyl group in the molecule such as 2-hydroxypropylethylenediamine can also be used. These chain extenders can be used alone or in combination of two or more.

A monovalent active hydrogen compound can also be used as a terminal blocker for the purpose of terminating 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, especially when it is desired to introduce a carboxyl group into the polyurethane resin. These terminal blocking agents can be used alone or in combination of two or more.

The weight average molecular weight of the polyurethane resin is preferably from 10,000 to 100,000, more preferably from 15,000 to 80,000.
The amount of polyurethane resin added is preferably 0.15 to 40% by mass, more preferably 1.0 to 35% by mass, based on the total amount of the ink.

Furthermore, the amine value of the polyurethane resin used in the liquid printing ink of the present invention is preferably 6.5 mgKOH/g or less. If the amine value exceeds 6.5 mgKOH/g, the blocking resistance tends to be poor. The range of 1.0 to 5.0 mgKOH/g is more preferable, and more preferably 1.0 to 3.5 mgKOH/g, from the viewpoint of being able to maintain good blocking resistance, plate fogging property, adhesiveness and extrusion lamination strength. g range.

The urethane resin used in the printed layer of the present invention preferably contains a polyurethane resin having a urea bond. A polyurethane resin having a urea bond can be obtained, for example, by reacting polypropylene glycol and a combined polyol with a diisocyanate compound in a proportion in which the isocyanate groups are in excess to obtain a prepolymer having terminal isocyanate groups, and dissolving the resulting prepolymer in an appropriate solvent. namely, ester solvents such as ethyl acetate, propyl acetate and butyl acetate, which are commonly used as solvents for non-toluene gravure inks; ketone solvents such as acetone, methyl ethyl ketone and methyl isobutyl ketone; methanol, ethanol, isopropyl alcohol, alcohol-based solvents such as n-butanol; hydrocarbon-based solvents such as methylcyclohexane and ethylcyclohexane; or a two-step method of reacting with a chain extender and (or) a terminal blocker in a mixed solvent thereof, or polypropylene glycol. and the combined polyol, diisocyanate compound, chain extender and/or terminal blocker are reacted at once in a suitable solvent among the above. Among these methods, the two-step method is preferred for obtaining a uniform polyurethane resin having urea bonds. Further, when producing a polyurethane resin by a two-step method, 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 preferred. If the equivalent ratio of the isocyanate group to the amino group is less than 1/1.3, the chain extender and/or the terminal blocker remain unreacted, causing yellowing of the polyurethane resin and odor after printing. may occur.

In the polyurethane resin having a urea bond, the urea bond concentration in the resin solid content is preferably in the range of 0.1 to 2.0 mmol/g, more preferably 0.3 to 1.5 mmol/g, still more preferably 0.5 mmol/g. It ranges from 5 to 1.0 mmol/g. The urea binding concentration referred to here can be calculated by the following formula (1).
Urea binding concentration = {(X ₁ /M ₁ +X ₂ /M ₂ + ... +X _i /M _i ) x 2-(W ₁ x OH ₁ + W ₂ x OH ₂ + ... + Wi _x OH _i ) /56100}×1000/S Formula (1)
In formula (1), symbols are as follows.
X ₁ : Weight of diisocyanate compound 1 M ₁ : Molecular weight of diisocyanate compound 1 X ₂ : Weight of diisocyanate compound 2 M ₂ : Molecular weight of diisocyanate compound 2 _{Xi : Weight of diisocyanate compound i M i :} Molecular weight of diisocyanate compound i W ₁ : Weight of polyol 1 OH ₁ : Hydroxyl value of polyol 1 W ₂ : Weight of polyol 2 OH ₂ : Hydroxyl value of polyol 2 W _i : Weight of polyol i OH _i : Hydroxyl value of polyol i S: Solid content of urethane resin Weight Further, it is preferable to use 1 to 30% by mass of polyether polyol having a number average molecular weight of 100 to 3,500 as a raw material based on 100% by mass of a polyurethane resin having a urea bond. Although details will be described later, examples of the polyether polyol resin include polyether polyols of polymers or copolymers such as ethylene oxide, propylene oxide, and tetrahydrofuran. Specifically, known general-purpose resins such as polyethylene glycol resin, polypropylene glycol resin, and polytetramethylene glycol resin may be used. By using the polyether polyol resin within the above range, the adhesiveness on the highly moisture-proof film is greatly improved, resulting in excellent blocking resistance and laminate strength. Of the polyether polyol resins, polyethylene glycol resins are particularly preferred for improving adhesion, anti-blocking properties and lamination strength on highly moisture-proof films.

If the number average molecular weight of the polyether polyol resin, which is a component of the polyurethane resin having a urea bond, is less than 100, the polyurethane resin film tends to be hard. If the number average molecular weight is more than 3,500, the polyurethane resin film tends to be brittle, resulting in poor blocking resistance of the ink film. If the amount of the polyether polyol resin is less than 1 part per 100 parts of the polyurethane resin having a urea bond, the solubility of the urethane resin in ketone, ester and alcohol solvents will be poor. In addition, the resolubility of the ink film in the solvent is deteriorated, and the tone reproducibility of the printed matter is deteriorated. On the other hand, when it exceeds 30 parts, there is a tendency that blocking resistance is inferior.

You may use a polyurethane resin in combination of 2 or more types. The type of urethane resin used in combination is not particularly limited, but containing the above polyurethane resin having a urea bond and a polyurethane resin having no urea bond improves moderate flexibility and laminate strength. It is preferable from the viewpoint of When a polyurethane resin having a urea bond and a polyurethane resin not having a urea bond are used in combination, the solid content ratio of these is polyurethane resin having a urea bond:polyurethane resin not having a urea bond=50:50 to 99. :1 range is preferred, more preferably 60:40 to 99:1, still more preferably 70:30 to 99:1.

As the polyurethane resin having no urea bond, for example, one obtained by reacting a polyol, a polyisocyanate, and optionally a chain extender having two or more hydroxyl groups can be used.

Examples of polyols that can be used include polyester polyols, polycaprolactone polyols, polyether polyols, polycarbonate polyols, polyacryl polyols, and polybutadiene polyols. These polyols may be used alone or in combination of two or more. Among these, it is preferable to use a polyester polyol from the viewpoint of further increasing the laminate strength by introducing an ester group into a polyurethane resin having no urea bond to increase the polarity.

As said polyester polyol, the thing obtained by well-known esterification reaction of the compound and polybasic acid which have two or more hydroxyl groups can be used, for example.

Examples of the compound having two or more hydroxyl groups include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, tri Glycols such as ethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol; 2-methyl-1,5-pentanediol, 3-methyl-1, 5-pentanediol, 1,2-butanediol, 1,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propane Diol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3- Glycols having a branched structure such as hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, 2-methyl-1,8-octanediol; trimethylolpropane, trimethylolethane, pentaerythritol, Sorbitol and the like can be used. These compounds may be used alone or in combination of two or more.

Examples of the polybasic acid include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, and phthalic acid. Acids, anhydrides of these acids, and the like can be used. These polybasic acids may be used alone or in combination of two or more.

The number average molecular weight of the polyol is preferably in the range of 500 to 8,000, more preferably in the range of 800 to 5,000, even more preferably in the range of 900 to 3,000. The number average molecular weight of the polyester polyol is a value measured under the following conditions by a gel permeation chromatography (GPC) method.
Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were connected in series and used.

"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 Book "TSKgel G2000" (7.8 mm I.D. x 30 cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40°C
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4% by mass)
Standard sample: A calibration curve was created using the following standard polystyrene.

(standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
As the polyisocyanate, various known polyisocyanates generally used in the production of polyurethane resins as described above can be used. Among them, it is preferable to use an aliphatic polyisocyanate and/or an alicyclic polyisocyanate from the point of obtaining appropriate flexibility, and from the point that the adhesive strength can be further improved by excellent cohesion, 1,6-hexa More preferably, methylene diisocyanate is used.

Examples of the chain extender having two or more hydroxyl groups include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexa aliphatic polyols such as methylene glycol, saccharose, methylene glycol, glycerin and sorbitol; Compounds having a number average molecular weight in the range of 50 to 400, such as aromatic polyols such as hydroquinone, can be used. These chain extenders may be used alone or in combination of two or more. The number average molecular weight of the chain extender is the value obtained by measuring in the same manner as the number average molecular weight of the polyol.

Examples of the method for producing a polyurethane resin having no urea bond include known methods such as solution polymerization and extrusion molding using a twin-screw extruder.

As a method of producing by solution polymerization, for example, the polyol, an organic solvent, and if necessary, the chain extender having two or more hydroxyl groups are charged and stirred, and then the polyisocyanate is added, for example, 40 to 100 °C for 3 to 10 hours.

As a method of performing extrusion molding with the twin-screw extruder, for example, in separate tanks of the twin-screw extruder, the polyol and optionally the chain extender having two or more hydroxyl groups, and the polyisocyanate are added. They are separately added, heated if necessary, then kneaded together in an extruder, and extruded through a die to obtain a pellet-like or sheet-like polyurethane resin). When obtaining the polyurethane resin in the form of pellets, it is possible to adopt an air hot cut method in which pellets are formed in air, an underwater hot cut method in which pellets are formed in water, or the like.

Molar ratio [NCO/OH] between hydroxyl groups (derived from the polyol and the chain extender) and isocyanate groups (derived from the polyisocyanate) when producing a polyurethane resin having no urea bond is preferably in the range of 0.8 to 1.2, more preferably in the range of 0.9 to 1.1, in any production method. Moreover, alcohol such as ethanol, methanol, or butanol may be added for the purpose of deactivating the remaining isocyanate groups after the production of the urethane resin having no urea bond.

The content of the polyurethane resin used in the liquid ink composition in the ink (the solid content of the polyurethane resin) should be 4% by mass or more based on the total amount of the ink, from the viewpoint of ensuring sufficient adhesion of the ink to the substrate. From the viewpoint of ink viscosity and work efficiency during ink production and printing, the content is preferably 25% by mass or less, more preferably 6 to 15% by mass. The lower limit of the solid content mass ratio in the ink is preferably 5% by mass, more preferably 7% by mass, more preferably 10% by mass, and more preferably 15% by mass. More preferred. The upper limit of the solid content weight ratio in the ink is preferably 90% by mass, more preferably 80% by mass, more preferably 70% by mass, and further preferably 60% by mass. preferable.

Binder resins other than urethane resins include nitrocellulose, cellulose resins such as cellulose acetate propionate (CAP) and cellulose acetate butyronate (CAB), and chlorinated polyolefin resins such as chlorinated polypropylene resins. , polyamide resins, acrylic resins, vinyl chloride-vinyl acetate copolymer resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, vinyl chloride resins such as polyvinyl chloride resins, polyester resins, alkyd resins, rosin resins Resins, rosin-modified maleic acid resins, ketone resins, cyclized rubbers, chlorinated rubbers, butyrals, petroleum resins, and the like can be mentioned. Among them, chlorinated polyolefin resins are preferable from the viewpoint of improving the laminate strength, and these may be used alone or in combination with the urethane resin.

(chlorinated polyolefin resin)
The chlorinated polyolefin resin is not particularly limited as long as it is a polyolefin resin in which at least part of hydrogen atoms are substituted with chlorine atoms. The weight average molecular weight of the chlorinated polyolefin is preferably from 5,000 to 100,000, more preferably from 5,000 to 70,000, and still more preferably from 7,000 to 50,000. Further, the chlorine content of the chlorinated polyolefin resin is preferably 25 to 45% by mass in order to improve the adhesiveness to the substrate. From the viewpoint of solubility in organic solvents, the chlorine content is more preferably 26 to 43% by mass. Here, the chlorine content refers to the percentage by mass of chlorine atoms contained in 100% by mass of the chlorinated polyolefin resin. From the viewpoint of balance with blocking resistance, the chlorinated polyolefin resin is contained in 0.1 to 2.5% by mass, preferably 0.2 to 2.3% by mass, based on 100% by mass of the ink.

Since the chlorinated polyolefin resin has a flexible alkyl group as a branched structure, it is a flexible resin even at low temperatures and contributes to the improvement of substrate adhesion. The structure of the polyolefin resin in the chlorinated polyolefin resin is not particularly limited. For example, resins containing homopolymers or copolymers of α-olefin unsaturated hydrocarbons such as polypropylene, poly-1-butene and poly-4-methyl-1-pentene are preferred. Among them, those containing a polypropylene structure (that is, a chlorinated polypropylene structure) are particularly preferred.

The content of the chlorinated polyolefin resin used in the liquid ink composition of the present invention in the ink (solid content of the polyurethane resin) is 0 with respect to the total amount of the ink from the viewpoint of sufficient adhesion of the ink to the substrate. 0.1% by mass or more, preferably 5% by mass or less, more preferably 0.3 to 3% by mass from the viewpoint of appropriate ink viscosity and work efficiency during ink production and printing. Further, the lower limit of the solid content mass ratio in the ink is preferably 0.2% by mass, more preferably 0.5% by mass, more preferably 0.8% by mass. 0% by mass is more preferred. In addition, the upper limit of the solid content weight ratio in the ink is preferably 8.0% by mass, more preferably 6.0% by mass, and more preferably 4.0% by mass. It is more preferably 0% by mass.

(Fibrous resin)
Examples of cellulose-based resins include cellulose acetate propionate, cellulose acetate butyrate and other cellulose ester resins, nitrocellulose (also referred to as nitrocellulose), hydroxyalkylcellulose, and carboxyalkylcellulose. The cellulose ester resin preferably has an alkyl group, and examples of the alkyl group include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, pentyl group, hexyl group and the like. may have a substituent.

As the cellulose resin, among the above, cellulose acetate propionate, cellulose acetate butyrate, and nitrocellulose are preferable. Nitrocellulose is particularly preferred. As for the molecular weight, the weight average molecular weight is preferably 5,000 to 200,000, more preferably 10,000 to 50,000. Further, those having a glass transition temperature of 120° C. to 180° C. are preferable.

Nitrocellulose (nitrocellulose) is obtained as a nitric ester obtained by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the six-membered ring of the anhydride glucopyranose group in natural cellulose with nitric acid groups. preferable.

By using nitrocellulose (nitrocellulose), high dispersibility in pigments can be obtained, so if it is used as a coating agent for surface printing, it is suitable because it can improve the strength of the printing ink coating film. . The nitrocellulose (nitrocellulose) preferably has a nitrogen content of 10 to 13% by mass and an average polymerization degree of 30 to 500, more preferably a nitrogen content of 10 to 13% by mass and an average polymerization degree of 45 to 290. . On the other hand, when a cellulose ester resin is contained, it is necessary to balance lamination strength and blocking resistance.

The amount of cellulose resin to be added is 0.2% by mass or more based on the total amount of ink from the viewpoint of sufficient adhesion of the ink to the substrate, and it is necessary to achieve a suitable ink viscosity and work efficiency during ink production and printing. From the viewpoint of , it is preferably 1% by mass or less, more preferably in the range of 0.3 to 0.8% by mass. In addition, the lower limit of the solid content mass ratio in the ink is preferably 0.5% by mass, more preferably 1.0% by mass, and more preferably 1.5% by mass. 0% by mass is more preferred. The upper limit of the solid content weight ratio in the ink is preferably 5.0% by mass, more preferably 4.0% by mass, and more preferably 3.0% by mass. It is more preferably 0% by mass.

(vinyl chloride-vinyl acetate copolymer resin)
In the liquid ink composition, the ratio of the vinyl chloride-vinyl acetate copolymer to the total amount of the binder resin is 20% by mass or less. The proportion of the vinyl chloride-vinyl acetate copolymer is preferably 15% by mass or less, preferably 10% by mass or less, preferably less than 8% by mass, and 5% by mass with respect to the total amount of the binder resin. It is preferably less than 3% by weight, and most preferably 0% by weight, that is, it contains no vinyl chloride-vinyl acetate copolymer. This is because the laminate strength tends to decrease as the ratio of the vinyl chloride-vinyl acetate copolymer to the total amount of the binder resin increases.

When a vinyl chloride-vinyl acetate copolymer resin is contained, the vinyl chloride-vinyl acetate copolymer resin is not particularly limited as long as it is a copolymer of vinyl chloride and vinyl acetate. As for the molecular weight, a weight average molecular weight of 5,000 to 100,000 is preferable, and 10,000 to 70,000 is more preferable. The structure derived from the vinyl acetate monomer is preferably 1 to 30% by mass, and the structure derived from the vinyl chloride monomer is preferably 70 to 95% by mass, based on 100% by mass of the solid content of the vinyl chloride-vinyl acetate copolymer resin. In this case, the solubility in organic solvents is improved, and the adhesion to substrates, film physical properties, scratch resistance and the like are improved.
From the viewpoint of solubility in organic solvents, those containing a hydroxyl group derived from a vinyl alcohol structure are also preferred. The hydroxyl value is preferably 20-200 mgKOH/g. Also, the glass transition temperature is preferably 50°C to 90°C.

It is preferable that the liquid ink composition further does not contain a ketone resin. Laminate strength tends to decrease when a ketone resin is also contained.

(Organic solvent)
Organic solvents used in liquid printing inks are not particularly limited, but examples include aromatic hydrocarbon organic solvents such as toluene, xylene, Solvesso #100 and Solvesso #150, hexane, methylcyclohexane, heptane, octane, decane, and the like. and various ester organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, normal 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 may be used alone or in combination of two or more.

In terms of work hygiene during printing and the toxicity of packaging materials, use ethyl acetate, propyl acetate, isopropanol, normal propanol, etc., and do not use aromatic solvents such as toluene or ketone solvents such as methyl ethyl ketone. is more preferred.

Among them, a mixture of isopropyl alcohol/ethyl acetate/methoxypropanol is more preferable from the viewpoint of solubility in polyurethane resin and nitrocellulose. For drying adjustment, glycol ethers can be added as long as they are less than 10% by mass of the total amount of the ink.

(coloring agent)
Pigments are preferable as colorants used in liquid printing inks, and inorganic pigments and organic pigments used in general inks, paints, recording agents, and the like can be mentioned. Examples of organic pigments include soluble azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, anthanthrone, dianthraquinonyl, anthrapyrimidine, perylene, perinone, quinacridone, Thioindigo-based, dioxazine-based, isoindolinone-based, quinophthalone-based, azomethineazo-based, flavanthrone-based, diketopyrrolopyrrole-based, isoindoline-based, indanthrone-based, and carbon black-based pigments can be used. Also, for example, Carmine 6B, Lake Red C, Permanent Red 2B, Disazo Yellow, Pyrazolone Orange, Carmine FB, Chromophtal Yellow, Chromophtal Red, Phthalocyanine Blue, Phthalocyanine Green, Dioxazine Violet, Quinacridone Magenta, Quinacridone Red, Indance Ron blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, daylight fluorescent pigments, and the like. Both non-acid-treated pigments and acid-treated pigments can be used. Specific examples of preferred organic pigments are given below.

Examples of black pigments include C.I. I. Pigment Black 1, C.I. I. Pigment Black 6, C.I. I. Pigment Black 7, C.I. I. Pigment Black 9, C.I. I. Pigment Black 20 and the like.

Examples of the indigo pigment include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:1, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 15:4, C.I. I. Pigment Blue 15:5, C.I. I. Pigment Blue 15:6, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 17:1, C.I. I. Pigment Blue 22, C.I. I. Pigment Blue 24:1, C.I. I. Pigment Blue 25, C.I. I. Pigment Blue 26, C.I. I. Pigment Blue 60, C.I. I. Pigment Blue 61, C.I. I. Pigment Blue 62, C.I. I. Pigment Blue 63, C.I. I. Pigment Blue 64, C.I. I. Pigment Blue 75, C.I. I. Pigment Blue 79, C.I. I. Pigment Blue 80 and the like.

Examples of green pigments include C.I. I. Pigment Green 1, C.I. I. Pigment Green 4, C.I. I. Pigment Green 7, C.I. I. Pigment Green 8, C.I. I. Pigment Green 10, C.I. I. Pigment Green 36 and the like.

Examples of red pigments include C.I. I. Pigment Red 1, C.I. I. Pigment Red 2, C.I. I. Pigment Red 3, C.I. I. Pigment Red 4, C.I. I. Pigment Red 5, C.I. I. Pigment Red 6, C.I. I. Pigment Red 7, C.I. I. Pigment Red 8, C.I. I. Pigment Red 9, C.I. I. Pigment Red 10, C.I. I. Pigment Red 11, C.I. I. Pigment Red 12, C.I. I. Pigment Red 15, C.I. I. Pigment Red 16, C.I. I. Pigment Red 17, C.I. I. Pigment Red 18, C.I. I. Pigment Red 19, C.I. I. Pigment Red 20, C.I. I. Pigment Red 21, C.I. I. Pigment Red 22, C.I. I. Pigment Red 23, C.I. I. Pigment Red 31, C.I. I. Pigment Red 32, C.I. I. Pigment Red 38, C.I. I. Pigment Red 41, C.I. I. Pigment Red 43, C.I. I. Pigment Red 46, C.I. I. Pigment Red 48, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 48:2, C.I. I. Pigment Red 48:3, C.I. I. Pigment Red 48:4, C.I. I. Pigment Red 48:5, C.I. I. Pigment Red 48:6, C.I. I. Pigment Red 49, C.I. I. Pigment Red 49:1, C.I. I. Pigment Red 49:2, C.I. I. Pigment Red 49:3, C.I. I. Pigment Red 52, C.I. I. Pigment Red 52:1, C.I. I. Pigment Red 52:2, C.I. I. Pigment Red 53, C.I. I. Pigment Red 53:1, C.I. I. Pigment Red 53:2, C.I. I. Pigment Red 53:3, C.I. I. Pigment Red 54, C.I. I. Pigment Red 57, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 58, C.I. I. Pigment Red 58:1, C.I. I. Pigment Red 58:2, C.I. I. Pigment Red 58:3, C.I. I. Pigment Red 58:4, C.I. I. Pigment Red 60:1, C.I. I. Pigment Red 63, C.I. I. Pigment Red 63:1, C.I. I. Pigment Red 63:2, C.I. I. Pigment Red 63:3, C.I. I. Pigment Red 64:1, C.I. I. Pigment Red 68, C.I. I. Pigment Red 68, C.I. I. Pigment Red 81:1, C.I. I. Pigment Red 83, C.I. I. Pigment Red 88, C.I. I. Pigment Red 89, C.I. I. Pigment Red 95, C.I. I. Pigment Red 112, C.I. I. Pigment Red 114, C.I. I. Pigment Red 119, C.I. I. Pigment Red 122, C.I. I. Pigment Red 123, C.I. I. Pigment Red 136, C.I. I. Pigment Red 144, C.I. I. Pigment Red 146, C.I. I. Pigment Red 147, C.I. I. Pigment Red 149, C.I. I. Pigment Red 150, C.I. I. Pigment Red 164, C.I. I. Pigment Red 166, C.I. I. Pigment Red 168, C.I. I. Pigment Red 169, C.I. I. Pigment Red 170, C.I. I. Pigment Red 171, C.I. I. Pigment Red 172, C.I. I. Pigment Red 175, C.I. I. Pigment Red 176, C.I. I. Pigment Red 177, C.I. I. Pigment Red 178, C.I. I. Pigment Red 179, C.I. I. Pigment Red 180, C.I. I. Pigment Red 181, C.I. I. Pigment Red 182, C.I. I. Pigment Red 183, C.I. I. Pigment Red 184, C.I. I. Pigment Red 185, C.I. I. Pigment Red 187, C.I. I. Pigment Red 188, C.I. I. Pigment Red 190, C.I. I. Pigment Red 192, C.I. I. Pigment Red 193, C.I. I. Pigment Red 194, C.I. I. Pigment Red 200, C.I. I. Pigment Red 202, C.I. I. Pigment Red 206, C.I. I. Pigment Red 207, C.I. I. Pigment Red 208, C.I. I. Pigment Red 209, C.I. I. Pigment Red 210, C.I. I. Pigment Red 211, C.I. I. Pigment Red 213, C.I. I. Pigment Red 214, C.I. I. Pigment Red 216, C.I. I. Pigment Red 215, C.I. I. Pigment Red 216, C.I. I. Pigment Red 220, C.I. I. Pigment Red 221, C.I. I. Pigment Red 223, C.I. I. Pigment Red 224, C.I. I. Pigment Red 226, C.I. I. Pigment Red 237, C.I. I. Pigment Red 238, C.I. I. Pigment Red 239, C.I. I. Pigment Red 240, C.I. I. Pigment Red 242, C.I. I. Pigment Red 245, C.I. I. Pigment Red 247, C.I. I. Pigment Red 248, C.I. I. Pigment Red 251, C.I. I. Pigment Red 253, C.I. I. Pigment Red 254, C.I. I. Pigment Red 255, C.I. I. Pigment Red 256, C.I. I. Pigment Red 257, C.I. I. Pigment Red 258, C.I. I. Pigment Red 260, C.I. I. Pigment Red 262, C.I. I. Pigment Red 263, C.I. I. Pigment Red 264, C.I. I. Pigment Red 266, C.I. I. Pigment Red 268, C.I. I. Pigment Red 269, C.I. I. Pigment Red 270, C.I. I. Pigment Red 271, C.I. I. Pigment Red 272, C.I. I. Pigment Red 279, and the like.
Examples of purple pigments include C.I. I. Pigment Violet 1, C.I. I. Pigment Violet 2, C.I. I. Pigment Violet 3, C.I. I. Pigment Violet 3:1, C.I. I. Pigment Violet 3:3, C.I. I. Pigment Violet 5:1, C.I. I. Pigment Violet 13, C.I. I. Pigment Violet 19 (γ type, β type), C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 25, C.I. I. Pigment Violet 27, C.I. I. Pigment Violet 29, C.I. I. Pigment Violet 31, C.I. I. Pigment Violet 32, C.I. I. Pigment Violet 36, C.I. I. Pigment Violet 37, C.I. I. Pigment Violet 38, C.I. I. Pigment Violet 42, C.I. I. Pigment Violet 50, and the like.

Examples of yellow pigments include C.I. I. Pigment Yellow 1, C.I. I. Pigment Yellow 3, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, Pigment Yellow 17, C.I. I. Pigment Yellow 24, C.I. I. Pigment Yellow 42, C.I. I. Pigment Yellow 55, C.I. I. Pigment Yellow 62, C.I. I. Pigment Yellow 65, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 86, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 109, C.I. I. Pigment Yellow 110, C.I. I. Pigment Yellow 117, C.I. I. Pigment Yellow 120, Pigment Yellow 125, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 129, C.I. I. Pigment Yellow 137, C.I. I. Pigment, Yellow 138, C.I. I. Pigment Yellow 139, C.I. I. Pigment Yellow 147, C.I. I. Pigment Yellow 148, C.I. I. Pigment Yellow 150, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 153, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 166, C.I. I. Pigment Yellow 168, C.I. I. Pigment Yellow 174, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 185 and C.I. I. Pigment Yellow 213 and the like.
Examples of orange pigments include C.I. I. Pigment Orange 5, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 16, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 36, C.I. I. Pigment Orange 37, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 43, C.I. I. Pigment Orange 51, C.I. I. Pigment Range 55, C.I. I. Pigment Orange 59, C.I. I. Pigment Orange 61, C.I. I. Pigment Orange 64, C.I. I. Pigment Orange 71, or C.I. I. Pigment Orange 74 and the like.

Examples of brown pigments include C.I. I. Pigment Brown 23, C.I. I. Pigment Brown 25, or C.I. I. Pigment Brown 26 and the like.

Among them, as a preferable pigment, C.I. I. Pigment Black 7,
C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:1, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 15:4, C.I. I. pigment blue 15:6,
C.I. I. pigment green 7,
C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 48:2, C.I. I. Pigment Red 48:3, C.I. I. Pigment Red 146, C.I. I. Pigment Red 242, C.I. I. Pigment Red 185, C.I. I. Pigment Red 122, C.I. I. Pigment Red 178, C.I. I. Pigment Red 149, C.I. I. Pigment Red 144, C.I. I. pigment red 166,
C.I. I. Pigment Violet 23, C.I. I. pigment violet 37,
C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 180, C.I. I. pigment yellow 139,
As an orange pigment, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 64,
etc., and it is preferable to use at least one or two or more selected from these groups.

Inorganic pigments include white inorganic pigments such as titanium oxide, zinc oxide, zinc sulfide, barium sulfate, calcium carbonate, chromium oxide, silica, litbon, antimony white, and gypsum. Among inorganic pigments, the use of titanium oxide is particularly preferred. Titanium oxide exhibits a white color and is preferable from the viewpoints of coloring power, hiding power, chemical resistance and weather resistance. From the viewpoint of printing performance, the titanium oxide is preferably treated with silica and/or alumina.

Examples of non-white inorganic pigments include aluminum particles, mica (mica), bronze powder, chrome vermilion, yellow lead, cadmium yellow, cadmium red, ultramarine blue, Prussian blue, red iron oxide, yellow iron oxide, iron black, and zircon. Although the aluminum is in the form of powder or paste, it is preferable to use it in the form of paste from the viewpoints of handling and safety, and whether to use leafing or non-leafing is appropriately selected from the viewpoint of brightness and density.

The amount of the pigment is sufficient to ensure the density and coloring strength of the liquid printing ink, that is, 1 to 60% by mass of the total mass of the ink, and 10 to 90% by mass of the solid content in the ink. preferably included. Moreover, these pigments can be used individually or in combination of 2 or more types.

The liquid printing ink of the present invention may further contain waxes, chelate-based cross-linking agents, extender pigments, leveling agents, antifoaming agents, plasticizers, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc. can also In addition, although an appropriate amount of silica may be added for the purpose of improving the blocking resistance, the addition of silica tends to decrease the laminate strength. Therefore, the content of silica used in the liquid ink composition in the ink is It is preferably 5% by mass or less, preferably 3% by mass or less, preferably 1% by mass or less, and more preferably 0.5% by mass relative to the total mass of the ink. Further, it is preferably 5% by mass or less, preferably 4.0% by mass or less, preferably 3.0% by mass or less, based on the total mass of the solid content weight ratio in the ink. 0% by mass is more preferred.

Liquid printing inks can be produced by dissolving and/or dispersing binder resins, pigments, etc. in organic solvents. Specifically, an ink can be produced by producing a pigment dispersion by dispersing a pigment in an organic solvent using a binder 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. can do. 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, binder resins, pigments, 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.

The liquid printing ink that forms the printing layer of the present invention has excellent adhesion to a highly moisture-proof polypropylene film having a water vapor transmission rate of 3.0 g/m ² 24 hours or less at a thickness of 25 μm, and is used for printing on the film. It is useful as an ink for gravure printing using a gravure printing plate such as an electronic engraving intaglio, or flexographic printing using a flexographic printing plate such as a resin plate. First, inks for inkjet systems, in which ink is ejected from inkjet nozzles, are excluded.

That is, in the case of inkjet ink, ink droplets ejected from a nozzle directly adhere to a substrate to form a printed matter, whereas in the printing layer of the present invention, the printing ink is once adhered and transferred to a printing plate or printing pattern. After that, only the ink is brought into close contact with the substrate again, and dried as necessary to obtain a printed matter.

The film thickness of the printing ink formed by the gravure printing method or the flexographic printing method using the liquid printing ink is, for example, 10 μm or less, preferably 5 μm or less.

<Base material>
The substrate used in the printed layer of the present invention has a layer of polypropylene film with a water vapor transmission rate of at least 3.0 g/m ² ·24 hours at a thickness of at least 25 μm. The polypropylene film, having a thickness of 25 μm, has a water vapor transmission rate of 3.0 g/m ² ·24 measured under conditions of a temperature of 40° C. and a relative humidity of 90% RH in accordance with Japanese Industrial Standards (JISK7129:2008B method). hours or less, preferably 2.8 g/m ² ·24 hours or less, more preferably 2.5 g/m ² ·24 hours or less. That is, it is a polypropylene film having a low water vapor transmission rate and high moisture resistance as compared with a general polypropylene film. Such a polypropylene film having high moisture resistance may be either an unstretched film or a stretched film, and the manufacturing method is not limited, but from the viewpoint of high moisture resistance, a biaxially stretched polypropylene film is preferable.

The thickness of the polypropylene film is not particularly limited, and generally ranges from 1 to 500 μm, preferably from 5 μm to 100 μm. The thickness of the entire base material including the polypropylene film is not particularly limited, and is generally in the range of 1 to 500 μm, preferably 5 μm to 100 μm.

As such a polypropylene film substrate, commercially available products include, for example, biaxially oriented polypropylene film QH-1 (manufactured by Futamura Chemical Co., Ltd.), biaxially oriented polypropylene film WH-OP HM-1, HE-1 ( Mitsui Chemicals Tohcello Co., Ltd.) and the like.

The printing surface of the polypropylene film substrate is preferably subjected to corona discharge treatment, and aluminum, silica, alumina, or the like may be vapor-deposited in order to obtain higher moisture resistance. The above-mentioned "polypropylene film having a water vapor transmission rate of 3.0 g/m ² ·24 hours or less at a thickness of 30 µm" is a polypropylene single-layer film without vapor deposition or the like.

The printed material of the present invention may have not only one printed layer but also a plurality of printed layers on the substrate. For example, a laminate having at least a first printed layer and a second printed layer in this order on a polypropylene film substrate, or at least a first printed layer, a second printed layer and a third printed layer on a polypropylene film substrate Laminates can be made having the layers in that order. The liquid printing inks described above can be used for these printing layers. More specifically, for example, a first printed layer formed from a printing ink containing a coloring agent, a second white printed layer formed from a liquid printing ink containing a white pigment as a coloring agent, and a third and a white printed layer in this order. The first printed layer can form a pattern with a coloring agent, and the second white printed layer formed with a liquid printing ink containing a white pigment, and the third printed layer are used as the background of the pattern. be able to. When the second or third printed layer is an overprint varnish, it may not contain a coloring agent.

<Laminate>
The laminate of the present invention is obtained by laminating a plurality of substrates, and can be laminated by laminating a film layer on a printed layer of a printed matter with an adhesive or by extrusion lamination. An example of a laminate laminated by extrusion lamination is a laminate having a configuration in which polypropylene film substrate layer/printing ink layer/extruded resin layer/sealant layer are laminated in order.

(Extruded resin layer)
The extruded resin layer is formed by extrusion-laminating a thermoplastic resin after forming a printing ink layer. A step may be provided in which the laminate film having the printed layer formed on the base material is temporarily wound up to form a roll, or the extruded resin layer may be provided as it is without being wound up in a roll.

Polyolefin-based resins such as polyethylene-based resins and polypropylene-based resins are preferable as the thermoplastic resin used for the extruded resin layer. Examples of polyethylene-based resins include linear polyethylenes such as linear low-density polyethylene (LLDPE) and low-density polyethylene (LDPE), and branched polyethylenes. Examples of polypropylene-based resins include propylene homopolymer, propylene -Propylene/α-olefin random copolymers such as ethylene copolymers, propylene-butene-1 copolymers and propylene-ethylene-butene-1 copolymers, metallocene catalyst-based polypropylenes, and the like. may be used alone or in combination. In addition, a known resin may be used in combination as a material for forming the extruded resin layer.

The extruded resin layer may be a single extruded resin layer, or may be a multi-layer extruded resin layer laminated by a coextrusion lamination method. In the case of multiple layers, the composition of each layer can be appropriately selected according to the application and performance required by the laminate (sealant layer)
The laminate of the present invention can have a sealant layer on the extruded resin layer. The material of the sealant layer is not particularly limited, and the same material as that used for the base material layer can be used. film (OPP: biaxially oriented polypropylene film) is preferably used. The sealant layer can be formed by simultaneously applying the film used for the sealant layer while flowing the molten resin layer when forming the extruded resin layer.

The layer structure of the laminate is not limited to the structure of polypropylene film substrate layer/printing ink layer/extruded resin layer/sealant layer described above. For example, a configuration having a primer layer on the printing ink layer may be employed, or a laminate having no sealant layer may be employed.

Moreover, the structure of the laminate of the present invention may be, for example, a laminate obtained by laminating another substrate to a substrate layer or an extruded resin layer. The other base material is not particularly limited, and can be appropriately selected according to the application and required functions of the laminate.

When a film layer is attached to a printed layer of a printed material as a laminate of the present invention with an adhesive, a known material can be used as the adhesive without limitation. preferably included. .

<Packaging material>
The printed matter and laminate of the present invention can be used as a multilayer packaging material for the purpose of protecting foods, pharmaceuticals, and the like. When used as a multilayer packaging material, the layer structure may vary depending on the contents, usage environment, and usage pattern.

The packaging material of the present invention is obtained, for example, by using the laminate of the present invention, superimposing the sealant film surfaces of the laminate on each other, and then heat-sealing the peripheral edges. As a bag-making method, the laminate of the present invention is folded or overlapped so that the inner layer surface (sealant film surface) faces each other, and the peripheral edge is sealed, for example, by a side seal type, a two-sided seal type, There are three-sided seal type, four-sided seal type, envelope pasted seal type, palm pasted seal type, pleated seal type, flat bottom seal type, square bottom seal type, gusset type, and other heat seal methods. be done. The packaging material of the present invention can take various forms depending on the contents, environment of use, and form of use. A self-supporting packaging material (standing pouch) or the like is also possible. As a heat sealing method, known methods such as bar sealing, rotary roll sealing, belt sealing, impulse sealing, high frequency sealing and ultrasonic sealing can be used.

After the packaging material of the present invention is filled with contents through the opening, the opening is heat-sealed to produce a product using the packaging material of the present invention. The use of the packaging material is not particularly limited, but it can be suitably used for food packaging, pharmaceuticals, sanitary, cosmetics, electronic materials, building materials, industrial materials, and the like. Contents to be filled include rice crackers, bean confections, nuts, biscuits, cookies, wafer confections, marshmallows, pies, half-baked cakes, candies, snacks, bread, snack noodles, instant noodles, dried noodles, and pasta. , aseptic packaged rice, rice porridge, rice porridge, packaged mochi, staples such as cereal foods, pickles, boiled beans, natto, miso, frozen tofu, tofu, mushrooms, konjac, processed wild plants, jams, peanut cream, salads, frozen Vegetables, processed agricultural products such as processed potatoes, processed hams, bacon, sausages, processed chicken products, processed livestock products such as corned beef, fish hams and sausages, fish paste products, kamaboko, seaweed, tsukudani, bonito flakes, salted fish, Processed marine products such as smoked salmon and cod roe, fruits such as peaches, mandarin oranges, pineapples, apples, pears and cherries, vegetables such as corn, asparagus, mushrooms, onions, carrots, radishes, and potatoes, hamburgers, and meat. Frozen and chilled prepared foods such as bowls, fried seafood, gyoza, and croquettes, prepared foods such as chilled side dishes, butter, margarine, cheese, cream, instant creamy powder, dairy products such as infant formula powder, liquid seasonings, and retort pouches Examples include foods such as curry and pet food. It can also be used as a packaging material for cigarettes, disposable body warmers, medicines, supplements, infusion packs, vacuum insulation materials, and the like.

EXAMPLES The present invention will be described more specifically with reference to Examples. Hereinafter, "parts" and "%" are based on mass.

In addition, 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 HLC8420 system manufactured by Tosoh Corporation.
Separation column: Four TSKgel Super HZ 1000 to 4000 manufactured by Tosoh Corporation are used.
Column temperature: 40°C. Moving bed: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd.
Flow rate: 0.35 ml/min. Sample concentration: 0.3% by mass.
Sample injection volume: 10 μL (tetrahydrofuran solution with a sample concentration of 0.3% by mass) Detector: Differential refractometer.

(Polyurethane resin solution Pu1)
80 parts of neopentyl glycol adipate diol (hydroxyl value: 56.6 mg KOH / g) and 20 parts of polyethylene glycol (hydroxyl value: 278 mg KOH / g) and 29.68 parts of isophorone diisocyanate were charged and reacted at 90° C. for 10 hours under a stream of nitrogen to produce a urethane prepolymer having an isocyanate group content of 2.84% by weight, to which 69.8 parts of ethyl acetate was added. was added to form a homogeneous solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 7.97 parts of isophoronediamine, 0.11 parts of di-n-butylamine, 139.1 parts of ethyl acetate and 112.5 parts of isopropyl alcohol, and the mixture was heated at 45°C for 5 hours. After reacting with stirring for hours, a polyurethane resin solution Pu1 was obtained. The resulting polyurethane resin solution Pu1 had a resin solid content concentration of 30.4% by weight and a urea bond concentration of {(29.68÷222×2−(80×56.6+20×278)÷56100)×1000/137. 76=0.64 mmol/g, and the weight average molecular weight (hereinafter referred to as Mw) of the resin solid content was 54,000.

(Polyurethane resin solution Pu2)
100 parts of a polyester polyol (hydroxyl value: 108 mgKOH/g) made from neopentyl glycol and sebacic acid and 32. isophorone diisocyanate were placed in a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube. 3 parts 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 3.08% by mass. A homogeneous solution was obtained. Next, the urethane prepolymer solution was added to a mixture of 8.47 parts of isophoronediamine, 0.46 parts of di-n-butylamine, 143 parts of ethyl acetate and 115 parts of isopropyl alcohol, and the reaction was stirred at 45°C for 5 hours. to obtain a polyurethane resin solution Pu2. The obtained polyurethane resin solution Pu2 had a resin solid content concentration of 29.9% by mass and a weight average molecular weight of 54,000.

(Polyurethane resin solution Pu3)
Polyester polyol-1 (polyester polyol obtained by reacting neopentyl glycol, 1,6-hexanediol and adipic acid, number average molecular weight; 2 ,000) and 400 parts by mass of normal propyl acetate were charged and stirred, then 8.0 parts by mass of 1,6-hexamethylene diisocyanate and 100 ppm of tin octylate were added, and the mixture was heated at 80°C. By reacting for 3 hours, a normal propyl acetate solution (Pu3) of polyurethane resin was obtained. The obtained polyurethane resin solution Pu3 had a resin solid content concentration of 20.0% by mass and a weight average molecular weight of 86,000.

(Vinyl chloride vinyl acetate copolymer resin solution Ev)
A vinyl chloride-vinyl acetate copolymer resin having a hydroxyl group (resin monomer composition in mass%, vinyl chloride/vinyl acetate/vinyl alcohol = 92/3/5, hydroxyl value (mgKOH) = 64) was made into a 15% solution with ethyl acetate, This was designated as a vinyl chloride-vinyl acetate copolymer resin solution Ev.

(chlorinated polyolefin solution)
A commercially available chlorinated polypropylene resin was made into a 30% solids solution with ethyl acetate, and this was used as a chlorinated polyolefin (chlorinated PP) solution.
(Adjustment of cellulose acetate propionate resin solution Ca)
To 20 parts of cellulose acetate propionate CAP482-0.5 (manufactured by Eastman Chemical Co.), a mixed solution of isopropyl alcohol/ethyl acetate/n-propyl acetate/methylcyclohexane (ratio by weight: 25/25/13/10) was added. 80 parts were added and thoroughly mixed to prepare a cellulose ester resin solution Ca.

(Adjustment example 1)
6.7 parts of the resulting vinyl chloride-vinyl acetate copolymer resin solution Ev, 12 parts of a red pigment ("SYMULER RED 3530" manufactured by DIC Corporation), and a mass ratio of ethyl acetate:propyl acetate:isopropyl alcohol of 4. A total of 49.1 parts of 30.4 parts of a 4:2 mixed organic solvent was kneaded to prepare a pigment dispersion.

Next, the pigment dispersion was further added with 32.4 parts of polyurethane resin solution Pu1, 1 part of chlorinated polyolefin solution, 2.3 parts of cellulose ester resin solution Ca, and 0 silica ("Silysia 350" manufactured by Fuji Silysia Chemical Co., Ltd.). 5 parts and 14.7 parts of a mixed organic solvent having a mass ratio of ethyl acetate:propyl acetate:isopropyl alcohol of 4:4:2 were added and stirred to prepare a liquid ink composition.

(Adjustment Examples 2 to 8 and Comparative Adjustment Examples 1 to 7)
According to the formulations shown in Tables 1 to 4, each liquid ink for printing was produced in the same procedure as in Preparation Example 1.

(Examples 1 to 8, Comparative Examples 1 to 7)
[Manufacturing method of film print]
The viscosity of the resulting liquid ink for printing was adjusted to 16 seconds (25°C) with a mixed solvent of ethyl acetate/propyl acetate/isopropyl alcohol = 40/40/20 (mass ratio) with a Zahn cup #3 (manufactured by Rigosha). Then, a highly moisture-proof biaxially oriented polypropylene film U (Mitsui Chemicals Tohcello Co., Ltd. WH-OP HM-1 thickness 25 μm) and a biaxially oriented polypropylene film W ( P2161 thickness 20 μm manufactured by Toyobo Co., Ltd.), biaxially oriented polypropylene X (FOA thickness 20 μm manufactured by Futamura Chemical Co., Ltd.),
and dried at 45°C to produce a printed material. Film U is a polypropylene film that satisfies the condition that a water vapor transmission rate at a thickness of 25 μm is 3.0 g/m ² ·24 hours or less, and film W and film X have a water vapor transmission rate at a thickness of 25 μm of 3.0 g/m. It is a polypropylene film that does not satisfy the condition of m ² · 24 hours or less.
The corona-treated surfaces of films U to X were printed.

The following evaluations were carried out on the obtained prints.

[Printability: highlight transfer/plate fogging]
In the blurring test, using a gravure proofing machine with a plate depth of 35 μm and a plate circumference of 600 mm φ, and a printing speed of 200 m / min as described in the manufacturing method of film prints, the highlight printed part (halftone dot area Less than 10%) were visually evaluated for highlight transfer based on the area ratio of blurring, and plate fogging based on the degree of contamination of the non-printed area.
(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.

[Extrusion lamination strength]
White ink adjusted as follows was printed on the printing surface of the film print by a gravure proofing machine equipped with a gravure plate having a plate depth of 35 μm.

White ink: Viscosity of ink obtained by blending 100 parts by mass of a commercially available white ink (Finert R794 White G8, manufactured by DIC Graphics Co., Ltd.) with a curing agent (CVL Hardener No. 10, manufactured by DIC Corporation) at a ratio of 4 parts by mass. was adjusted to 15 seconds (25° C.) with a mixed solvent of ethyl acetate/propyl acetate/isopropyl alcohol=40/40/20 (mass ratio) with Zahn cup #3 (manufactured by Rigosha).

An isocyanate-based anchor coating agent was used on the printed surface, and molten polyethylene was laminated by an extrusion laminator. After that, it was aged at 40° C. for 24 hours to obtain an extrusion laminate.

The obtained laminate was cut into a width of 15 mm and subjected to a 90 degree peel test at a pulling speed of 150 mm/min.

(Evaluation criteria)
5: Lamination strength is 2 N/15 mm or more.
4: The laminate strength is 1.5 to 2 N/15 mm or more and less than 5 N/15 mm.
3: The laminate strength is 1 to 1.5 N/15 mm or more and less than 4 N/15 mm.
2: The laminate strength is 0.5 to 1 N/15 mm or more and less than 3 N/15 mm.
1: The laminate strength is less than 0.5 N/15 mm.

"○" in the item of film in the table represents the film used.

As shown in the table, the laminates of Examples were able to improve the lamination strength without lowering the printability. From the results of Examples 1 and 2 and Comparative Examples 1 and 2, it can be seen that the laminate strength increases as the amount of the vinyl chloride-vinyl acetate copolymer resin solution Ev decreases. On the other hand, as shown in Comparative Examples 3 to 6, when using a polypropylene film that does not satisfy the condition that the water vapor transmission rate at a thickness of 25 μm is 3.0 g/m ² 24 hours or less, vinyl chloride-vinyl acetate copolymer Good lamination strength can be obtained regardless of the presence or absence of the resin solution Ev, but high moisture resistance due to the film cannot be obtained.

Claims (5)

a substrate;
Having a printed layer provided on the base material,
As the base material, a polypropylene film having a water vapor transmission rate of 3.0 g/m ² 24 hours or less at a thickness of 25 μm,
The printed matter, wherein the printed layer contains a urethane resin as a binder resin, and the ratio of the vinyl chloride-vinyl acetate copolymer to the total amount of the binder resin is 20% by mass or less. 2. The printed matter according to claim 1, wherein the printed layer does not contain a vinyl chloride-vinyl acetate copolymer. 3. The printed matter according to claim 1, wherein the printed layer further contains at least one selected from chlorinated polyolefin resins, cellulose resins, maleic acid resins, polyester resins, acrylic resins and polyamide resins. A laminate in which a film layer is attached to the printed layer of the printed material according to any one of claims 1 to 3. 5. The laminate according to claim 4, wherein the film layer is a resin layer laminated by melt extrusion.