JP2022169881A - Overcoat agent, and printed matter - Google Patents

Abstract

To provide an overcoat agent which can exhibit high gloss equal to or higher than that of a film surface of a laminate in addition to various physical properties such as adhesion, heat resistance and odor, even in surface printing structure.SOLUTION: An overcoat agent contains a binder resin and an isocyanate curing agent which is arranged on a printing layer and forms a transparent protective layer, where the binder resin contains a vinyl chloride copolymer resin and a polyester-based resin having a ring structure, and contains 30 mass% or more of the vinyl chloride copolymer resin in the total mass of the binder resin.SELECTED DRAWING: None

Description

The present invention relates to an overcoating agent and printed matter using the same.

BACKGROUND ART Printing inks are printed on flexible packages and other packages using film substrates such as polyester films, nylon films, polyolefin films, etc., in order to provide design, beauty, or product information. Printing on a film substrate is roughly classified into front printing, in which printing is performed directly on the surface of the film, and reverse printing, in which ink is printed on the back of the film. In the case of packaging with a surface printing configuration, the printed layer is arranged on the outermost side, and the printed layer can be directly viewed. On the other hand, in the case of packaging with reverse printing, the film substrate is the outermost layer, and the printed layer is sandwiched (laminated) between the substrate and a thermoplastic substrate called sealant. Therefore, in the package printed on the reverse side, unlike the package printed on the front side, there is a difference that the printed layer can be seen through the film substrate.

Since the surface printing composition forms a printing ink layer on the outermost surface, it is often inferior in glossiness, scratch resistance, and heat resistance as compared with the film substrate (Patent Document 1). On the other hand, in the case of back-side printing composition (laminated laminate), the physical properties of the film substrate itself are effectively utilized in the outermost layer of the package. In comparison, it has the feature that high glossiness and scratch resistance can be easily obtained. However, in this method, after printing the printing ink on the base material, another film must be pasted on the printed layer, which is a time-consuming process, and in addition, the adhesion between the film base material and the printed layer, delamination ( There are many cases where the physical properties are insufficient due to the process, such as floating), and there is also a problem in terms of cost because an adhesive and a lamination process are required.

Therefore, a method of forming a protective layer with an overcoat agent on the surface of the surface-printed layer is also being investigated in order to impart high glossiness and heat resistance to the composition or package printed on the surface. . According to this method, it can be expected that glossiness and scratch resistance can be imparted to the same extent as a laminated laminate without going through a complicated manufacturing process unlike that of a laminated laminate.
However, conventional overcoating agents include urethane resin-based coating agents (Patent Document 2), acrylic resin-based coating agents (Patent Document 3), amide resin-based coating agents (Patent Document 4), poly A lactic acid-based overcoating agent (Patent Document 5) and the like have been proposed, but all of them have room for improvement in glossiness, heat resistance, odor, etc., compared to laminated laminates.

JP 2019-119824 A JP 2018-145283 A Japanese Patent No. 5828196 JP 2016-079306 A JP 2003-147265 A

It is an object of the present invention to provide an overcoat agent that can express high gloss equivalent to or higher than that of the film surface of a laminated laminate, in addition to various physical properties such as adhesion, heat resistance, and odor, even in surface printing compositions. and

As a result of earnest research on the subject of the present application, the present inventors have found that the problem can be solved by using the overcoat agent described below, and have completed the present invention.

That is, the present invention provides an overcoat agent containing a binder resin and an isocyanate curing agent for forming a transparent protective layer disposed on a printed layer,
The binder resin comprises a vinyl chloride copolymer resin and a polyester resin having a ring structure, and relates to an overcoat agent containing the vinyl chloride copolymer resin in an amount of 30% by mass or more based on the total mass of the binder resin.

The present invention also relates to the overcoat agent, wherein the polyester-based resin having a ring structure includes a polyester-based resin having an aromatic ring structure.

The present invention also relates to the above overcoating agent, wherein the ring structure content in the total solid mass of the overcoating agent is 0.5 to 10% by mass or less.

The present invention also relates to the overcoat agent, wherein the mass ratio of the vinyl chloride copolymer resin and the polyester resin having a ring structure is 80:20 to 40:60.

The present invention also relates to the above overcoat agent, wherein the polyester-based resin having a ring structure contains a vegetable oil-modified alkyd resin having a ring structure.

The present invention also relates to the overcoat agent, wherein the isocyanate curing agent has a ring structure.

The present invention also relates to a printed material having, in order, a substrate, a printed layer and a transparent protective layer formed from the above overcoat agent.

INDUSTRIAL APPLICABILITY According to the present invention, it has become possible to provide an overcoat agent capable of exhibiting high gloss equivalent to or higher than that of the film surface of a laminate laminate, in addition to various physical properties such as adhesion, heat resistance, and odor.
In addition, it has become possible to manufacture printed materials with performance equivalent to or higher than laminated laminates even in the case of surface printing, which was difficult in the past. ₂ can also contribute to reduction.

Embodiments of the present invention will be described in detail below, but the description of the embodiments or requirements described below is an example of embodiments of the present invention, and the present invention is limited to these contents as long as the gist thereof is not exceeded. not.

The present invention provides an overcoat agent containing a binder resin and an isocyanate curing agent for forming a transparent protective layer disposed on a printed layer,
The binder resin is an overcoat agent comprising a vinyl chloride copolymer resin and a polyester resin having a ring structure, and containing the vinyl chloride copolymer resin in an amount of 60% by mass or more based on the total mass of the binder resin. . The binder resin contains a vinyl chloride copolymer resin and a polyester resin having a ring structure, and the vinyl chloride copolymer resin is contained in an amount of 60% by mass or more in the total mass of the binder resin, thereby achieving high gloss, adhesion, and heat resistance. , odor, etc. can be improved.
The transparent protective layer preferably has a surface gloss value (60°) of 80-135.
The overcoat agent contains a binder resin containing a polyester-based resin and an isocyanate curing agent. The polyester resin in the overcoat agent imparts flexibility and adhesion, and the isocyanate curing agent imparts heat resistance and scratch resistance. In order to improve the gloss value and adhesion, the polyester resin must have a ring structure, and the ring structure is preferably an aromatic ring structure.

The gloss value is a value measured according to JISZ8741, and is a measured value at an incident angle of 60°. The gloss value can be measured using, for example, a BYK-Gardner Micro-TRI-glossmeter under the measurement conditions of an incident angle of 60° and an acceptance angle of 60°.

The overcoat agent of the present invention is preferably used for surface printing. In this specification, surface printing means that when printing on a paper substrate or plastic substrate, the printing ink and overcoat agent are printed on the substrate in that order, and the printed pattern can be confirmed from the printed surface. is printed on the front. The transparent protective layer made of the overcoat agent is the outermost layer in the printed matter of the present invention. Each material constituting the overcoat agent of the present invention will be described below.

<Binder resin>
The binder resin is a resin component other than the curing agent, additive, and solvent contained in the overcoat agent, and the vinyl chloride copolymer resin is contained in an amount of 30% by mass or more in the total amount of the binder resin. The content is preferably 40% by mass or more, more preferably 60% by mass or more, and the upper limit is preferably 95% by mass or less, 90% by mass or less, or 80% by mass or less.
Moreover, the polyester resin having a ring structure is preferably contained in an amount of 70% by mass or less, 60% by mass or less and 50% by mass or less.

<Polyester-based resin having a ring structure>
The polyester resin having a ring structure is, for example, a polyester resin obtained by reacting a polyhydric alcohol and a carboxylic acid using a known esterification polymerization reaction, an alkyd resin described below, or the like, wherein the polyhydric alcohol and/or polyester resins in which the carboxylic acid has a ring structure.
The polyester-based resin having a ring structure is not particularly limited as long as it contains 50% by mass or more of the polyester structure in the total mass, and is appropriately produced by a known method. The content of the ring structure in the polyester resin is preferably 1 to 80% by mass, more preferably 5 to 30% by mass. The content of the ring structure is preferably 0.5 to 10% by mass based on the total mass of solid content in the overcoat agent. In addition, solid content means the total mass of the non-volatile component of an overcoat agent.
The ring structure preferably includes an aromatic ring structure, an alicyclic ring structure, and a heterocyclic ring structure (such as a pyranose ring structure). Among them, an aromatic ring structure is preferable.

The weight average molecular weight of the polyester resin is preferably 500 to 200,000, more preferably 2,000 to 150,000. This is because adhesion, blocking resistance, work efficiency in the ink printing process, printability, and the like are improved.

Among polyhydric alcohols, alicyclic alcohols include 1,4-cyclohexanediol, 1,2-cyclohexanediol, 1,4-cyclohexanedimethanol, 1,2-cyclohexanedimethanol, and spiroglycol. , isosorbide and the like. In addition, monofunctional alcohols such as cyclohexanol, cyclohexaneethanol, 4-tert-butylcyclohexanol, menthol, 2-ethyl-4-(2,2,3-trimethyl-3-cyclopentenyl)-2-butene-1 -ol, 4-isopropylcyclohexanol, 2-(tert-butyl)cyclohexanol, etc. can also be used in combination.
A polyhydric alcohol can be used individually or in mixture of 2 or more types.

Among polyhydric alcohols, aromatic alcohols include 1,4-benzenedimethanol, 1,3-bis(2-hydroxyethoxy)benzene, 1,2-bis(2-hydroxyethoxy)benzene, 1,4-bis (2-Hydroxyethoxy)benzene, hydroquinone, 2,2-bis(4-β-hydroxyethoxyphenyl)propane, etc., and these can be used alone or in combination of two or more.

Among dibasic acids, alicyclic dibasic acids include 1,2-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, 1,1-cyclopentanediacetic acid, decahydro-1 , 4-naphthalenedicarboxylic acid and the like.

Among dibasic acids, aromatic dibasic acids include phthalic acid, isophthalic acid, terephthalic acid, 1,2-phenylene diacetic acid, 1,3-phenylene diacetic acid, 1,4-phenylene diacetic acid, 4-(carboxy methyl)benzoic acid, and the like, and these can be used alone or in combination of two or more.

A polyhydric alcohol having no ring structure or a dibasic acid having no ring structure can also be used for the polyester resin.

Examples of polyhydric alcohols having no alicyclic structure include, but are not limited to, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2-methyl-1,3-propanediol, 2 -ethyl-2-butyl-1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, 1,5-pentanediol, 1,2-pentanediol, 3-methyl-1, 5-pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol, glycerin, trimethylolpropane, trimethylolethane, 1,2,6 -hexanetriol, 1,2,4-butanetriol, sorbitol, pentaerythritol and the like.

Examples of dibasic acids having no ring structure include, but are not limited to, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, and phthalic acid. etc. If necessary, monobasic acids such as formic acid, acetic acid, propionic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoic acid, hexanoic acid, heptanoic acid, octanoic acid, nonanoic acid, decanoic acid, oleic acid, and linoleic acid may be used together.

Additionally, acid anhydrides may be used, such as succinic anhydride, methyl succinic anhydride, 2,2-dimethyl succinic anhydride, butyl succinic anhydride, isobutyl succinic anhydride, hexyl succinic anhydride, octyl Succinic anhydride, dodecenyl succinic anhydride, phenyl succinic anhydride, glutaric anhydride, 3-allyl glutaric anhydride, 2,4-dimethyl glutaric anhydride, 2,4-diethyl glutaric anhydride, butyl glutaric anhydride, hexyl anhydride Glutaric Acid, Maleic Anhydride, 2-Methyl Maleic Anhydride, 2,3-Dimethyl Maleic Anhydride, Butyl Maleic Anhydride, Pentyl Maleic Anhydride, Hexyl Maleic Anhydride, Octyl Maleic Anhydride, Decyl Maleic Anhydride, Dodecyl Anhydride maleic acid, 2,3-dichloromaleic anhydride, phenyl maleic anhydride, 2,3-diphenyl maleic anhydride, itaconic anhydride, citraconic anhydride, phthalic anhydride, 4-methylphthalic anhydride, dimer acid, 1, 2,3,6-tetrahydrophthalic anhydride, 3-methyl-1,2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride, 3-methyl-1 , 2,3,6-tetrahydrophthalic anhydride, 4-methyl-1,2,3,6-tetrahydrophthalic anhydride, methylbutenyl-1,2,3,6-tetrahydrophthalic anhydride, chlorendic anhydride, anhydrous head acid, biphenyldicarboxylic anhydride, hymic anhydride, endomethylene-1,2,3,6-tetrahydrophthalic anhydride, methyl-3,6-endomethylene-1,2,3,6-tetrahydrophthalic anhydride, 1-cyclopentene-1,2-dicarboxylic anhydride, methylcyclohexenedicarboxylic anhydride, trimellitic anhydride, 1,8-naphthalenedicarboxylic anhydride, octahydro-1,3-dioxo-4,5-isobenzofurandicarboxylic and acid anhydrides.

(alkyd resin)
Alkyd resin is one form of polyester resin having the above ring structure, and alkyd resin synthesized by condensation polymerization (condensation polymerization) of carboxylic acid compound, fatty acid (including animal and vegetable oils), and alcohol compound. and alkyd resins obtained by reacting the above fatty acid or its fatty acid monoester with a carboxylic acid compound, followed by an esterification reaction with an alcohol compound. All of them correspond to alkyd resins modified with oils (fat-modified alkyd resins).
The alkyd resin used in the present invention preferably has a hydroxyl value of 5 to 200 mgKOH/g, more preferably 20 to 150 mgKOH/g. The weight average molecular weight of the alkyd resin is preferably 500 to 200,000, more preferably 2,000 to 150,000. The content of the ring structure in the total amount of the alkyd resin is preferably 1 to 80% by mass, more preferably 5 to 30% by mass.

As the carboxylic acid compound used for synthesizing the alkyd resin, polybasic acids such as dibasic acids are preferable, and the dibasic acids include the above aromatic carboxylic acids (including anhydrides), alicyclic carboxylic acids ( including anhydrides) are preferably mentioned. Among them, aromatic carboxylic acids (including anhydrides) are preferable, and phthalic anhydride, phthalic acid, isophthalic acid, terephthalic acid and the like are preferable as the compound.

As the alcohol compound used for synthesizing the alkyd resin, alicyclic alcohols, aromatic alcohols, and alcohols having no ring structure are preferably used, and the same alcohols as described above can be preferably used. Among them, it is preferable to use an alcohol having no ring structure, and examples of the alcohol include dihydric alcohol compounds such as ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, propylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, Preferable examples include butanediol, 1,6-hexanediol, 1,2-hexanediol, 1,5-hexanediol, 2,5-hexanediol, cyclohexanedimethanol, and nepentyl glycol.
Trihydric or higher alcohol compounds (mono or di or tri) glycerin, (mono or di or tri) trimethylol ethane, (mono or di or tri) trimethylol propane, (mono or di or tri) trimethylol alkane, ( Aliphatic polyhydric alcohols such as mono-, di- or tri)pentaerythritol and sorbitol are exemplified.

The fatty acid may be a mixed fatty acid, and suitable examples of fatty acids include caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, oleic acid, linoleic acid, linolenic acid, palmitic acid, and stearic acid. .

Examples of the above animal and vegetable oils include cannabis oil, linseed oil, hollyhock oil, oatica oil, olive oil, cacao oil, kapok oil, kaya oil, mustard oil, mustard oil, mustard oil, paulownia oil, kukui oil, walnut oil, poppy oil, sesame oil, Safflower oil, radish seed oil, soybean oil, large linseed oil, camellia oil, corn oil, rapeseed oil, niger oil, bran oil, palm oil, castor oil, sunflower oil, grape seed oil, hentou oil, pine seed oil, Cottonseed oil, coconut oil, peanut oil, dehydrated castor oil, and the like.

Examples of the fatty acid monoester include alkyl esters formed from the fatty acid and an alcohol, and suitable examples of the alcohol include alkanols such as methanol, ethanol, propanol, isopropanol, butanol, and isobutanol.

(Ring structure content in total solid mass of overcoating agent)
The content of the ring structure in the total solid mass of the overcoat agent can be calculated by the following formula.
Ring structure content (%) = total atomic weight of all atoms forming ring structures in one molecule of raw material/molecular weight of raw material Here, the raw material constitutes an overcoat agent such as a binder resin or an isocyanate-based curing agent. Refers to a compound, and all the atoms constituting the ring structure in one molecule of the raw material are directly connected to the atoms (carbon atoms or heteroatoms) constituting the ring structure itself such as an aromatic ring and the atoms constituting the ring structure itself. It is defined as hydrogen atoms and does not include atoms of substituents such as methyl groups and nitro groups.
For example, in the case of a trimethylolpropane adduct compound (XDI-TMP adduct) of xylylene diisocyanate, which is a raw material of the isocyanate curing agent, the ring structure (C ₆ H ₄ ), which is an aromatic group, with respect to the total molecular weight of 698.7 , and the total molecular weight (C ₁₈ H ₁₂ ) is 228.3, so the content of the ring structure is 228.3/698.7=33%.
If the above ring structure content is calculated on the basis of the binder resin, it will be the ring structure content in the binder resin, and if it is calculated on the basis of the solid content, it will be the ring structure content in the solid content.

<Vinyl chloride copolymer resin>
The vinyl chloride copolymer resin is not particularly limited as long as it contains structural units derived from vinyl chloride and structural units derived from other monomers. Among them, vinyl chloride-vinyl acetate copolymer resin and vinyl chloride-acrylic copolymer resin are preferable.

<Vinyl chloride-vinyl acetate copolymer resin>
The vinyl chloride-vinyl acetate copolymer resin is a copolymer of vinyl chloride and vinyl acetate, and preferably has a weight average molecular weight of 5,000 to 100,000, more preferably 20,000 to 70,000. is more preferred. The structure derived from the vinyl acetate monomer in 100% by mass of the solid content of the vinyl chloride-vinyl acetate copolymer resin is preferably 1 to 30% by mass, and the structure derived from the vinyl chloride monomer is preferably 70 to 95% by mass. . In this case, the solubility in organic solvents is improved, and the adhesion to substrates, film physical properties, laminate strength and the like are improved.
Further, since the solubility in organic solvents is improved, those containing hydroxyl groups derived from vinyl alcohol by saponification reaction or copolymerization are more preferable, and the hydroxyl value is preferably 20 to 200 mgKOH/g. Also, the glass transition temperature is preferably 50°C to 90°C.

<Vinyl chloride-acrylic copolymer resin>
Vinyl chloride-acrylic copolymer resin is mainly composed of copolymer resin of vinyl chloride monomer and acrylic monomer. ) preferably contains hydroxyalkyl acrylates. The acrylic monomer may be incorporated into the main chain of polyvinyl chloride in blocks or randomly, or may be graft-polymerized to the side chains of polyvinyl chloride. The vinyl chloride-acrylic copolymer resin preferably has a weight average molecular weight of 10,000 to 100,000, more preferably 30,000 to 70,000. Also, the hydroxyl value is preferably 20 to 200 mgKOH/g, and the glass transition temperature is preferably 50°C to 90°C.

Further, the structure derived from the vinyl chloride monomer in the vinyl chloride-acrylic copolymer resin is preferably 70 to 95% by mass based on 100% by mass of the solid content of the vinyl chloride-acrylic copolymer resin. In this case, the solubility in organic solvents is improved, and the adhesion to substrates, film physical properties, laminate strength and the like are improved.

In the following description, (meth)acrylic to (meth)acrylate mean methacrylic and acrylic, methacrylate and acrylate respectively.

The acrylic monomer preferably has a hydroxyl group, examples of which include 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 3-hydroxypropyl (meth)acrylate, and 2-hydroxypropyl (meth)acrylate. -(meth)acrylic acid such as hydroxybutyl, 3-hydroxybutyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, 6-hydroxyhexyl (meth)acrylate, 8-hydroxyoctyl (meth)acrylate, etc. Hydroxyalkyl esters, glycol mono(meth)acrylates such as polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, 1,4-cyclohexanedimethanol mono(meth)acrylate, caprolactone-modified (meth)acrylates, hydroxy and ethyl acrylamide. Among these, 2-hydroxyethyl (meth)acrylate, 4-hydroxybutyl (meth)acrylate, and 2-hydroxypropyl acrylate are more preferable because they improve solubility in solvents. These can be used alone or in combination of two or more. In addition, acrylic monomers other than those described above may be contained at any time.

In one embodiment, the binder resin preferably contains the vinyl chloride copolymer resin and the polyester resin within a certain ratio range. In this case, the vinyl chloride copolymer resin and the polyester resin are preferably used in a weight ratio of 40:60 to 80:20, more preferably 50:50 to 70:30. The polyester-based resin preferably contains an alkyd resin. The binder resin preferably contains a total of 70% by mass or more, more preferably 80% by mass or more, of the polyester resin and the vinyl chloride copolymer resin.

<Combined resin>
In the embodiment of the present invention, the binder resin is also suitable when other resins are used in addition to the above polyester resins and vinyl chloride copolymer resins. Examples include, but are not limited to, polyurethane resins. , polyamide resin, rosin resin, ethylene-vinyl acetate copolymer resin, vinyl acetate resin, acrylic resin, styrene resin, dammar resin, styrene-maleic acid copolymer resin, styrene-acrylic copolymer resin, terpene resin, phenol modification Terpene resins, ketone resins, cyclized rubbers, chlorinated rubbers, butyral resins, polyacetal resins, petroleum resins, modified resins thereof, and the like can be mentioned. These resins can be used alone or in combination of two or more.

<Isocyanate curing agent>
An isocyanate curing agent is used in the overcoat agent of the present invention in order to improve heat resistance. In order to improve gloss, the isocyanate curing agent preferably has a ring structure. The ring structure is preferably the same structure as in the case of the polyester-based resin. Among them, an alicyclic ring structure and/or an aromatic ring structure are more preferable.
As a specific embodiment of the isocyanate curing agent, polyisocyanate compounds and modified isocyanate compounds can be preferably used. Specifically, the modified isocyanate compound is preferably a dimer allophanate-type isocyanate compound, a trimer biuret-type isocyanate compound, an adduct-type isocyanate compound, an isocyanurate-type isocyanate compound, or the like. The biuret-type isocyanate compound is an isocyanate compound having a structure in which urea is dimerized. Further, the isocyanurate-type isocyanate compound means an isocyanate compound that is a cyclic trimer of a polyisocyanate compound. The adduct-type isocyanate compound refers to an adduct of a polyisocyanate compound and a polyhydric alcohol, and examples thereof include reaction products with xylylene diisocyanate.
As the polyisocyanate compound, diisocyanates are preferable, and aromatic diisocyanates such as xylylene diisocyanate, diphenylmethane diisocyanate and tolylene diisocyanate; alicyclic diisocyanates such as 1,4-cyclohexane diisocyanate and isophorone diisocyanate; Araliphatic diisocyanates such as α'-tetramethylxylylene diisocyanate are preferred.
Specific commercial products of modified isocyanate compounds include, for example, Duranate 24A-100, 22A-75P, TPA-100, TKA-100, P301-75E (manufactured by Asahi Kasei Corporation), Takenate D-160N and D-170N. , D-110N, D-101 (manufactured by Mitsui Chemicals), Desmodur N3200, N3600, Z4470BA, L75(C) (manufactured by Covestro).
The ring structure content in the isocyanate curing agent is preferably 5 to 50% by mass, more preferably 20 to 40% by mass. The ring structure preferably has an alicyclic group and/or an aromatic group. The isocyanate curing agent preferably has an isocyanate group (NCO) content defined in JISK6806 of 3 to 30% (mass %), more preferably 5 to 25%.

The isocyanate curing agent is preferably blended in an amount of 0.25 to 8 equivalents, more preferably 0.8 to 3 equivalents, per equivalent of the crosslinkable functional group (hydroxyl group, amino group, etc.) of the binder resin. The ratio of the binder resin to the isocyanate curing agent used is preferably 95:5 to 10:90 by mass, more preferably 90:10 to 20:80 by mass. Within this range, a sufficient cross-linking density can be obtained, and good heat resistance can be obtained.

<Additive>
The overcoating agent of the present invention can contain conventionally known additives as appropriate. agents, antistatic agents, viscosity modifiers, chelate cross-linking agents, trapping agents, antiblocking agents, wax components other than the above, silane coupling agents, and the like.

<Organic solvent>
The overcoating agent of the present invention preferably contains an organic solvent as a liquid medium (organic solvent-based overcoating agent). Examples of organic solvents used include, but are not limited to, aromatic organic solvents such as toluene and xylene, ketone organic solvents such as methyl ethyl ketone and methyl isobutyl ketone, ethyl acetate, n-propyl acetate, isopropyl acetate, Known organic solvents such as isobutyl acetate, ester-based organic solvents, alcohol-based organic solvents such as methanol, ethanol, n-propanol, isopropanol, and n-butanol, and glycol ether-based solvents such as ethylene glycol monopropyl ether and propylene glycol monomethyl ether. It can be used and can be mixed and used. Among them, organic solvents such as toluene and xylene that do not contain aromatic organic solvents (non-toluene organic solvents) are more preferable. Organic solvents consisting of ester-based organic solvents and alcohol-based organic solvents are more preferred. In this case, the glycol ether organic solvent may be contained in an amount of 6% by mass or less based on 100% by mass of the overcoat agent. The overcoating agent of the present invention may contain water as a liquid medium, but the content thereof is preferably 0.1 to 5% by mass based on 100% by mass of the liquid medium. However, it is not limited to these.

(Manufacture of overcoat agent)
The production of the overcoating agent is not particularly limited, and a binder resin solution in which a binder resin and an organic solvent are dissolved or dispersed, and a solvent are charged into a stirrer equipped with stirring blades, rotary blades, etc., mixed and stirred. The stirring speed is not particularly limited, and can be carried out at 50 to 300 rpm. In order to improve the handling and application properties of the overcoating agent, a solvent may be added as appropriate. Although the isocyanate curing agent can be charged at the beginning, it is preferable to mix the isocyanate curing agent immediately before use depending on the storage conditions and type of isocyanate curing agent. Since the overcoat agent is used depending on the printing method or the like, the viscosity is preferably 20 to 200 mPa·s.

(Application and printing of overcoat agent)
The overcoat agent of the present invention can be applied by a known printing method. For example, a gravure printing method, a flexographic printing method, a micro gravure printing method, and the like can be mentioned, and the gravure printing method is preferable. In the gravure printing method, the overcoat agent enters the recesses that become the image areas carved on the surface of the cylindrical cylinder, and after scraping off the overcoat agent in the non-image areas with a metal plate called a doctor, In this method, the remaining overcoat agent is transferred onto the printed film to form a coating layer. The amount of overcoat applied can be controlled by the depth of the recess. The coating on the printed film can be applied multiple times in consideration of film properties such as dryness after coating, glossiness of the coating film, scratch resistance, high-temperature hot water resistance, and the like. The amount of application and the number of times of application can be appropriately selected as the form of use of the overcoat agent. The thickness of the transparent protective layer formed from the overcoat agent of the present invention is preferably 0.5-10 μm, more preferably 1-6 μm.

It is preferable to dry the applied overcoat agent at a temperature of 40 to 80° C. to obtain a print having a tough transparent protective layer.

The overcoat agent of the present invention is applied onto a printed layer formed with printing ink to form a printed matter. The printing ink is preferably a printing ink comprising a binder resin, a pigment, a solvent and, if necessary, additives. Examples of binder resins constituting printing ink include, but are not limited to, urethane resins, polyamide resins, acrylic resins, vinyl chloride-vinyl acetate copolymer resins, nitrocellulose resins, chlorinated polypropylene resins, ethylene-vinyl acetate resins. Printing inks containing copolymer resins, vinyl acetate resins, polyester resins, alkyd resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubbers, chlorinated rubbers, butyral, petroleum resins, etc. are preferred. Among them, printing inks containing at least one selected from the group consisting of urethane resins, polyamide resins, acrylic resins, vinyl chloride-vinyl acetate copolymer resins, and nitrocellulose resins are more preferable. In particular, printing inks containing urethane resins are more preferable because they have good adhesion to film substrates.

The above urethane resin is prepared by a known method, for example, JP-A-62-153366, JP-A-62-153367, JP-A-1-236289, JP-A-2-64173, JP-A-2-64174. It can be obtained by the methods disclosed in JP-A-2-64175 and the like. Specifically, a polyol and a diisocyanate compound are reacted at a rate in which the isocyanate group is excessive to obtain a prepolymer with terminal isocyanate groups, and the resulting prepolymer is treated with a chain extender and / or reacted in an appropriate solvent. It is produced by a two-step method of reacting with a terminator, or by a one-step method of reacting a polyol, a diisocyanate compound, a chain extender and/or a reaction terminator in a solvent at once. Among these methods, the two-step method is preferable for obtaining a uniform urethane resin.

The printing ink may contain additives such as pigment dispersants, leveling agents, defoaming agents, leveling agents, waxes, trapping agents, plasticizers, infrared absorbers, ultraviolet absorbers, anti-blocking agents, Examples include antistatic agents and flame retardants.

As the pigment, C.I. listed in the Color Index that can be generally used in printing inks and paints. I. Pigments can optionally be used. Examples include colored pigments such as titanium oxide, red iron oxide, Prussian blue, ultramarine blue, carbon black and graphite, and extender pigments such as calcium carbonate, kaolin, clay, barium sulfate, aluminum hydroxide and talc. Examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo chelate pigments, condensed azo pigments, copper phthalocyanine pigments, and condensed polycyclic pigments. The content of these pigments can be 0.5 to 50% by weight in the printing ink.

Solvents used in printing inks include water, radiation-curable monomers, and the same solvents as those usable in the above overcoat agent, including known alcohol-based organic solvents, ketone-based organic solvents, ester-based organic solvents, Aliphatic hydrocarbon-based organic solvents and alicyclic hydrocarbon-based organic solvents can be used. Considering the solubility of the urethane resin and the resin used in combination, the drying property during printing, etc., it is preferable to mix them before use.

A printing ink can be produced by a known method of dispersing a pigment using a resin, a solvent, or the like. For example, a pigment dispersion is produced by dispersing a pigment in a solvent using a urethane resin, a combined resin, a dispersant, etc., and the resulting pigment dispersion is blended with a resin, an additive, etc. as necessary. .

(Base material)
As the substrate used in the present invention, a plastic substrate on a film, a paper substrate, or the like can be suitably used. Among them, the use of a plastic substrate is preferable, and a plastic substrate having thermoplasticity is preferable because a process such as heat sealing is required.
Examples of plastic substrates include polyethylene, polypropylene and other polyolefin substrates, polyethylene terephthalate, polylactic acid and other polyester substrates, polystyrene substrates, polystyrene resins such as AS resins and ABS resins, polycarbonate substrates, polyamide substrates, poly There are film-like and sheet-like ones made of vinyl chloride base material, polyvinylidene chloride base material, cellophane base material, paper base material, aluminum foil base material, etc., or composite materials thereof. Among them, a polyester base material and a polyamide base material having a high glass transition temperature are preferably used.

The base material may be subjected to vapor deposition coating treatment such as metal oxide on the surface and/or coating treatment such as polyvinyl alcohol. For example, GL- Examples include AE and IB-PET-PXB manufactured by Dai Nippon Printing Co., Ltd. Further, if necessary, those treated with additives such as antistatic agents and ultraviolet inhibitors, and those treated with corona treatment or low-temperature plasma treatment on the surface of the base material can also be used.

Examples of the plastic base material include (1) a single type plastic base material and (2) a multilayer plastic base material obtained by multilayering a plurality of types of plastic base materials. In the present invention, a multilayer plastic substrate is preferable from the viewpoint of toughness, moisture resistance, and the like. Furthermore, in the present invention, the multilayer plastic substrate is preferably a multilayer plastic substrate having heat sealability (thermoplasticity) on the side opposite to the printed side. The use of a multi-layered plastic base material has the advantage of simplifying the process of manufacturing a package, since the bag can be easily manufactured without post-processing after application of the overcoat agent.

Examples of the structure of the multilayer plastic substrate include two-layer structures such as PET/CPP, OPP/CPP, and Ny/CPP, PET/aluminum/CPP, PET/Ny/CPP, Ny/PET/CPP, Ny/evaporated PET/ There are a three-layer structure such as CPP and a four-layer structure of PET/aluminum/Ny/CPP, etc., which are laminated via an anchor coat agent and an adhesive. Even in such a multi-layered plastic substrate, if the printed surface is subjected to corona treatment, flame treatment, plasma treatment, etc., the adhesiveness of the printed ink layer is improved, which is preferable.

For lamination of plastic substrates, a known method, for example, an extrusion lamination method in which an imine-based, polybutadiene-based, or titanium-based anchor coating agent is used and molten polyethylene resin or the like is laminated. There is a dry lamination method in which a urethane-based adhesive is applied and laminated. Especially for applications requiring resistance to high-temperature hot water, a multilayer plastic substrate obtained by a dry lamination method is preferred.

The printed material of the present invention is obtained by printing a printing ink layer and an overcoat agent in this order on a plastic substrate. As described above, it is preferable to use a heat-sealable multi-layer film as the plastic substrate in terms of ease of post-processing.

The package thus obtained can be widely used as a packaging material for foods, medicines and the like. In addition, since it exhibits excellent high-temperature hot water resistance in a surface printing configuration, it can also be applied to applications that require high resistance in a conventional reverse printing configuration.

EXAMPLES The present invention will be described in detail below with reference to Examples, but the present invention is not limited to these Examples. Parts and % in the present invention represent parts by mass and % by mass unless otherwise specified.

<Synthesis of polyurethane resin for printing ink>
[Synthesis Example 1] (Preparation of urethane resin PU1 solution)
150 parts of polyester polyol (PMPA) with a number average molecular weight of 1,000 obtained by the reaction of adipic acid and 3-methyl-1,5-pentanediol, 50 parts of polypropylene glycol (PPG700) with a number average molecular weight of 700, isophorone diisocyanate 103.4 parts of (IPDI) and 75.8 parts of ethyl acetate (ethyl acetate) were reacted at 80° C. for 4 hours under a nitrogen stream to obtain a resin solution of a terminal isocyanate urethane prepolymer. Next, 44.6 parts of isophorone diamine (IPDA) and 736.2 parts of a mixed solvent of ethyl acetate/isopropanol (IPA) = 50/50 (mass ratio) were mixed, and 40 parts of the resin solution of the terminal isocyanate urethane prepolymer was added. °C to obtain a polyurethane resin solution PU1.

<Synthesis of Polyester Resin A for Overcoat Agent>
[Synthesis Example 2] (Preparation of polyester resin A solution)
190.1 parts of phthalic anhydride, 207.9 parts of castor oil, 38.6 parts of ethylene glycol, 63.4 parts of pentaerythritol, and 500.0 parts of ethyl acetate were charged into a reactor, and the temperature was adjusted to 160 to 160 parts while stirring under a nitrogen stream. It was gradually heated to 240° C. to carry out an esterification reaction. The reaction was carried out at 195°C for 1 hour or more, and when the acid value became 15 or less, the pressure in the reactor was gradually reduced to 1 to 2 Torr. . Polyester resin A has 6% by mass of aromatic ring structures.

<Synthesis of Polyester Resin B for Overcoat Agent>
[Synthesis Example 3] (Preparation of polyester resin B solution)
156.3 parts of terephthalic acid, 156.3 parts of isophthalic acid, 70.0 parts of ethylene glycol, 117.4 parts of neopentyl glycol, and 500.0 parts of ethyl acetate were charged into a reactor, and the temperature was adjusted to 160 to 160 parts while stirring under a nitrogen stream. It was gradually heated to 240° C. to carry out an esterification reaction. The reaction was carried out at 240° C. for 1 hour or longer, and when the acid value became 15 or less, the pressure in the reactor was gradually reduced to 1 to 2 Torr. . Polyester resin B has 11% by mass of an aromatic ring structure.

[Synthesis Example 4] (Preparation of polyester resin C solution)
143.1 parts of terephthalic acid, 100.1 parts of isophthalic acid, 52.3 parts of sebacic acid, 44.9 parts of ethylene glycol, 103.3 parts of neopentyl glycol, 56.3 parts of butyl ethyl propanediol, 500.0 parts of ethyl acetate The mixture was placed in a reactor and gradually heated to 160 to 240° C. with stirring under a nitrogen stream to carry out an esterification reaction. The reaction was carried out at 240°C for 1 hour or more, and when the acid value became 15 or less, the pressure in the reactor was gradually reduced to 1 to 2 Torr. . Polyester resin C has 24% by mass of aromatic ring structures.

[Synthesis Example 5] (Preparation of polyester resin D solution)
190.1 parts of hexahydrophthalic anhydride, 207.9 parts of castor oil, 38.6 parts of ethylene glycol, 63.4 parts of pentaerythritol, and 500.0 parts of ethyl acetate were charged into a reactor, and the mixture was stirred under a nitrogen stream at 160°C. The esterification reaction was carried out by gradually heating to ~240°C. The reaction was carried out at 195° C. for 1 hour or more, and when the acid value became 15 or less, the pressure in the reactor was gradually reduced to 1 to 2 Torr. A polyester resin D was obtained. Polyester resin D has 6% by mass of an alicyclic ring structure.

[Synthesis Example 6] (Preparation of polyester resin E solution)
[Comparative Synthesis Example 1] (Preparation of polyester resin E solution)
100 parts of DL-lactide, 100 parts of L-lactide, 0.2 parts of sodium isethionate, 0.5 parts of tin octylate as a ring-opening polymerization catalyst, and 200.7 parts of ethyl acetate were charged in a four-necked flask and placed under a nitrogen atmosphere. , and heated at 180° C. for 2 hours for ring-opening polymerization to obtain a polyester resin E. Polyester resin E does not contain structural units derived from dibasic acids and polyhydric alcohols. Polyester resin E does not have a ring structure.
[Synthesis Example 7] (Preparation of polyester resin F solution)
[Comparative Synthesis Example 1] (Preparation of polyester resin E solution)
200 parts of meso-lactide, 0.2 parts of sodium isethionate, 0.5 parts of tin octylate as a ring-opening polymerization catalyst, and 200.7 parts of ethyl acetate are charged in a four-necked flask and heated at 180° C. for 2 hours under a nitrogen atmosphere. It was heated and ring-opening polymerized to obtain a polyester resin E. Polyester resin F does not contain structural units derived from dibasic acids and polyhydric alcohols. Polyester resin F does not have a ring structure.

<Production of printing ink>
[Production Example 1] (Production of printing ink R1)
As a binder resin, 32 parts of urethane resin solution PU1 (solid content 30%), vinyl chloride-vinyl acetate copolymer resin (manufactured by Nisshin Chemical Co., Ltd., Solbin TAO, solid content 30%, ethyl acetate solution) 3 parts, chlorinated polypropylene 0.5 parts of resin (manufactured by Nippon Paper Industries, 370M, chlorine content 30%, solid content 50%) in terms of solid content, polyethylene wax (manufactured by Mitsui Chemicals, high wax 320P, average particle size 2.5 μm) 0.8 parts in terms of solid content, 10 parts of indigo pigment (CI Pigment Blue 15: 4), methyl ethyl ketone (MEK) / n-propyl acetate (NPAC) / isopropanol (IPA) = 40/40/20 ( mass ratio) were mixed and dispersed for 15 minutes in a bead mill to obtain printing ink R1.

[Production Examples 1 to 3] (Production of printing inks R1 to R3)
Printing inks R1 to R3 were obtained in the same manner as in Production Example 1, except that the raw materials and blending ratios shown in Table 1 were used.

The abbreviations and details of the raw materials in Table 1 are shown below.
・ Titanium oxide: Titanix JR-808 manufactured by Tayka
• Rosin-maleic acid resin: rosin-modified maleic acid resin. Marquedo No. manufactured by Arakawa Chemical Co., Ltd. 5, solid content 30%, ethyl acetate solution, softening point 145°C, hydroxyl value 0 mgKOH/g
• Polyamide resin: A polyamide resin having an amine value of 3.5 mgKOH/g, containing 50% by mass or more of structural units derived from dimer acid made from oleic acid and linoleic acid. Weight average molecular weight 6,000, solid content 30%, IPA solution.
• Cellulose resin: nitrocellulose. Solid content 30%, ethyl acetate/IPA solution, nitrogen content 11.5-12.2%, degree of polymerization 35-45, hydroxyl value 175 mgKOH/g
・Chelate cross-linking agent: Organotitanium-based chelate cross-linking agent

[Example 1] (Preparation of overcoating agent S1)
Polyester resin A solution (solid content 50% by mass) 6.6 parts, vinyl chloride-vinyl acetate copolymer resin (manufactured by Nisshin Chemical Co., Ltd., Solbin TAO, vinyl chloride 91% by mass, vinyl acetate 2% by mass, vinyl alcohol 7% by mass %, solid content 50% by mass) 26.5 parts, XDI-TMP adduct (trimethylolpropane adduct of xylylene diisocyanate NCO content 12% solid content 50% by mass) 3.2 parts, Kasozai DBS (manufactured by Toyokuni Oil Co., Ltd. 1.8 parts of dibutyl sebacate) and 61.8 parts of ethyl acetate were mixed and stirred with a disper for 30 minutes to obtain an overcoat agent S1 having a solid content of 20%. The XDI-TMP adduct was blended immediately before printing.

[Examples 2 to 17, Comparative Examples 1 to 4] (Preparation of overcoating agents S2 to S17 and SS1 to SS4)
Overcoat agents S2 to S17 and SS1 to SS4 were obtained in the same manner as in Example 1, except that the raw materials and blending ratios shown in Table 2 were used.

The abbreviations and details of the raw materials in Table 2 are shown below.
・TDI (toluene diisocyanate)-TMP adduct: solid content 50%, NCO content 13%
・HDI (hexamethylene diisocyanate)-TMP adduct: solid content 50%, NCO content 13%
・HDI-biuret: HDI-isocyanurate, solid content 50%, NCO content 23.5%
Vinyl chloride-hydroxyalkyl acrylate copolymer resin: Solbin VROH manufactured by Nissin Chemical Co., Ltd., vinyl chloride 73% by mass, vinyl acetate 16% by mass, hydroxyalkyl acrylate 11% by mass, solid content 50% by mass

<Preparation of printed matter using printing ink R2 and overcoating agent S1>
The printing ink R2 and the overcoating agent S1 were each diluted with ethyl acetate using Zahn cup #3 (manufactured by Rigo Co., Ltd.) so as to have a viscosity of 15 seconds at 25°C.
Using a gravure printing machine equipped with a gravure plate with a plate depth of 35 μm, a diluted printing ink R2 is applied to a polypropylene (OPP) film with a thickness of 30 μm under the conditions of a printing speed of 40 m / min and a dryer temperature of 50 ° C. and a printed film was obtained.
Next, using a gravure printing machine equipped with a gravure plate with a plate depth of 35 μm on the surface having the printing layer of the printing film prepared above, under the conditions of a printing speed of 40 m / min and a dryer temperature of 50 ° C., dilution The overcoating agent S1 was applied to obtain a printed material having a configuration of plastic substrate/printing layer/transparent protective layer.

<Production of printed matter using each printing ink and overcoat agent>
Using the combinations shown in Table 2 for the printing inks and overcoat agents obtained above, prints according to Examples 1 to 17 were produced in the same manner as in the production of the prints.

<Characteristic evaluation>
Using the overcoat agents obtained in the above Examples and Comparative Examples and their printed matter, the following evaluations were carried out. Table 2 shows the evaluation results.

<Gloss>
From the transparent protective layer side of the prints produced in the above examples and comparative examples, the gloss value was measured at an incident angle of 60° and an acceptance angle of 60° using a BYK-Gardner Micro-TRI-glossmeter. Evaluation criteria are shown below.
A (Excellent): The gloss value is 90 or more.
B (Possible): The gloss value is 80 or more and less than 90.
C (impossible): The gloss value is less than 80.
A and B are within a practically acceptable range.

<Adhesion (tape adhesion resistance)>
A cellophane tape (12 mm width) manufactured by Nichiban Co., Ltd. was attached on the transparent protective layer of the printed matter prepared in the above Examples and Comparative Examples, and the degree of peeling of the printed layer or the transparent protective layer was evaluated when the tape was rapidly peeled off. Evaluation criteria are shown below.
A (excellent): No peeling of the printed layer or the transparent protective layer.
B (Possible): Less than 50% of the printed layer or transparent protective layer is peeled off.
C (improper): 50% or more of the printed layer or transparent protective layer is peeled off.
A and B are within a practically acceptable range.

<Heat resistance>
The printed matter prepared in the above examples and comparative examples was cut into a size of 3 cm × 13 cm, respectively, and the glossy surface of aluminum foil (thickness 30 μm) cut into the same size was overlapped with the printed surface of the printed matter. . Using a heat sealer manufactured by Sentinel Co., Ltd., press the aluminum foil at 120° C. for 1 second at a pressure of 2×9.8 N/cm ² , and visually check the degree of peeling of the printed layer or the transparent protective layer when the aluminum foil is peeled off. Judged. Evaluation criteria are shown below.
A (excellent): No peeling at all at a seal bar temperature of 160°C.
B (acceptable): Not peeled at a seal bar temperature of 120°C, but peeled at 160°C.
C (impossible): peeled at a seal bar temperature of 120°C.
A and B are within a practically acceptable range.

<Blocking resistance>
The blocking resistance of the prints produced in the above examples and comparative examples was evaluated under the following conditions.
(sample and pressure)
Printed surface of OPP printed matter/non-corona treated surface of OPP substrate 10 kg/cm ²
(Standing conditions) 40° C.-80% RH for 48 hours (Evaluation method) Peel off the printed surface from the base material, and visually determine the degree of peeling of the ink film from the printed surface.
(criterion)
A (Excellent): The ink film on the printed surface does not peel off at all, and the peeling resistance is small. B (Acceptable): The peeled area of the ink film is 5% or more and less than 20%. C (Unacceptable): The peeled area of the ink film. is 20% or more A and B are in the range where there is no practical problem.

<Kneading resistance>
Each of the prints produced in the above examples and comparative examples was massaged 30 times with both hands and evaluated according to the following evaluation criteria. In addition, the measurement conditions were set to a test piece of 100 mm square.
A (Excellent): No peeling or peeling of the ink film B (Fair): Peeling of the ink film, but no peeling C (Poor): Peeling of the ink film be.

<Abrasion resistance>
The film strength of each of the prints produced in the above examples and comparative examples was measured using a Gakushin type rubbing fastness tester manufactured by Tester Sangyo Co., Ltd., and evaluated according to the following evaluation criteria. The measurement conditions were a test piece width of 20 mm, a load of 500 g, 100 reciprocations, and Kanakin No. 3.
A (excellent): no peeling of ink film B (acceptable): 10% or more and less than 30% of ink film peeling area C (poor): 30% or more of ink film peeling area Range.

<Reference Example 1: Evaluation of surface printed matter of printing ink only>
Printing ink R2 was diluted with a mixed solvent of ethyl acetate/IPA (mass ratio 70/30) using Zahn Cup #3 (manufactured by Rigosha) at 25° C. for 15 seconds.
Using a gravure printing machine equipped with a gravure plate with a plate depth of 35 μm, a diluted printing ink R3 is applied to an OPP film with a thickness of 30 μm under the conditions of a printing speed of 40 m / min and a dryer temperature of 50 ° C. A printed matter A1 having an imprint structure was obtained.
When the same evaluation as above was performed for printed matter A1 having a surface printing configuration, gloss: C, adhesion: A, heat resistance: A, blocking resistance: B, rubbing resistance: B, rub resistance: B. rice field.

<Reference Example 2: Evaluation of laminated laminate>
Printing ink R2 was diluted with a mixed solvent of ethyl acetate/IPA (mass ratio 70/30) using Zahn Cup #3 (manufactured by Rigosha) at 25° C. for 15 seconds.
Using a gravure printing machine equipped with a gravure plate with a plate depth of 35 μm, a diluted printing ink R2 is applied to an OPP film with a thickness of 30 μm under the conditions of a printing speed of 40 m / min and a dryer temperature of 50 ° C. to obtain a printed matter. A2 was obtained.
Next, using a dry laminating machine, a dry laminating adhesive (TM-340V / CAT-29B manufactured by Toyo-Morton Co., Ltd.) is applied on the printed layer of the printed matter A2, and VMCPP (aluminum deposition A non-stretched polypropylene film (thickness 25 μm) was laminated to obtain a laminate B1 in which the OPP substrate/printing layer/adhesive layer/VMCPP substrate were laminated in this order.
When the laminate B1 was evaluated in the same manner as above, the results were gloss: B, adhesion: A, heat resistance: A, blocking resistance: A, rubbing resistance: A, and abrasion resistance: A. In addition, evaluation of the said gloss evaluated from the OPP base-material side.

From the above evaluation results, by using the overcoat agent of the embodiment of the present invention, the gloss of the printed layer is improved more than the laminate laminated with the film, and good adhesion and heat resistance are achieved in the flexible packaging surface printing structure. It was shown that a printed matter with good odor was obtained.

Claims (7)

An overcoat agent containing a binder resin and an isocyanate curing agent for forming a transparent protective layer disposed on the printed layer,
The overcoat agent, wherein the binder resin comprises a vinyl chloride copolymer resin and a polyester resin having a ring structure, and the vinyl chloride copolymer resin is contained in an amount of 30% by mass or more based on the total mass of the binder resin. 2. The overcoat agent according to claim 1, wherein the polyester-based resin having a ring structure includes a polyester-based resin having an aromatic ring structure. 3. The overcoating agent according to claim 1, wherein the ring structure content in the total solid content of the overcoating agent is 0.5 to 10% by mass or less. 4. The overcoat agent according to any one of claims 1 to 3, wherein the weight ratio of the vinyl chloride copolymer resin and the polyester resin having a ring structure is 80:20 to 40:60. 5. The overcoat agent according to any one of claims 1 to 4, wherein the polyester resin having a ring structure comprises a vegetable oil-modified alkyd resin having a ring structure. The overcoat agent according to any one of claims 1 to 5, wherein the isocyanate curing agent has a ring structure. A printed matter comprising, in order, a substrate, a printed layer and a transparent protective layer formed from the overcoat agent according to any one of claims 1 to 6.