JP7601285B2 - Composition for forming removable film - Google Patents

Description

The present invention relates to a composition used to form a removable coating from a substrate.

In recent years, the problem of marine plastics has become evident, caused by plastics discarded or dumped in the ocean being broken down into fine particles (microplastics) in seawater. It is feared that these microplastics will enter the bodies of marine organisms, become concentrated, and affect the health of seabirds and humans through the food chain. One way to improve this marine plastic problem is recycling. Improving the recycling rate of resources such as soft packaging materials and plastic bottles will prevent plastics from entering the ocean. However, with current recycling, there is an issue that the film printed on the plastic substrate does not come off during the recycling process and gets mixed into the plastic, causing a deterioration in color and physical properties, and reducing the value of the recycled plastic. If it is possible to remove the film from the plastic substrate during the recycling process and solve this problem, the value of the recycled plastic will increase, leading to the entry of new recyclers and the establishment of separate collection by local governments. It is believed that this will improve the recycling rate and improve the marine plastic problem. Therefore, there is a demand for the development of a film-forming material that allows the film to be removed during the recycling process.
Furthermore, organic solvent-based printing inks, which are widely used as film-forming materials for plastic substrates, are being replaced by toluene-free and methyl ethyl ketone (MEK)-free inks out of consideration for the impact on worker health and the environment. Therefore, materials that solve the above problems must be developed with this in mind.

In the prior art, a method is disclosed in which a film containing a styrene-acrylic acid resin, a phenolic resin, and a styrene-maleic acid resin as a vehicle printed on a heat-shrinkable PET film is removed with alkaline water (Patent Document 1). Similarly, a method is disclosed in which a coating layer containing a styrene-maleic acid resin, a rosin-maleic acid resin, and an acrylic acid copolymer resin is disposed between printed layers of a heat-shrinkable PET film, and the coating layer is removed with alkaline water (Patent Documents 2 and 3). However, these techniques only guarantee the characteristics for a specific substrate, and are not sufficient in terms of providing an easy removal method. There was room for further study in providing a recycling method for plastic substrates that can remove a coating from a general-purpose plastic substrate containing polyolefin in a simple manner and easily remove a printed layer from the plastic substrate.
In addition, organic solvent-based printing inks for alkaline water detachment, which use urethane resins having an acid value as the binder resin, have also been disclosed (Patent Document 4, Patent Document 5, and Patent Document 6). However, when a urethane resin having an acid value is used as the main binder resin, it is expected that the adhesion to the substrate will be insufficient, and by imparting an acid value to the urethane resin, the viscosity of the resin will increase, and it will be necessary to use the above-mentioned solvents that have a large impact on health and the environment to adjust the viscosity, or the coexistence of an amine value and an acid value is avoided to reduce the viscosity, resulting in a decrease in suitability for lamination applications, and other problems will arise, so there remain issues to be solved before the ink can be used universally as a material from which a film can be detached.

On the other hand, packaging materials suitable for plastic recycling have also been disclosed in which a release layer made of printing ink is placed between two types of substrates, and the release layer is peeled off by treatment with a basic aqueous solution, allowing each substrate to be released (Patent Document 7, Patent Document 8, and Patent Document 9).

Patent No. 3822738 Patent No. 4653913 Patent No. 4451071 Patent No. 6638802 Patent No. 6631964 JP 2020-169280 A JP 2021-98294 A JP 2021-98295 A JP 2021-98546 A

However, it has been found that when attempting to remove the coating with an alkaline solution, the colorant contained in the coating may dissolve in the alkaline solution, causing the alkaline solution after the removal treatment (also referred to as the alkaline solution after treatment) to become colored.
If the alkaline solution after treatment is colored, it will cause environmental pollution problems and will increase the cost of waste liquid treatment, so it is necessary to prevent the alkaline solution after treatment from being colored.
Therefore, it is desirable to provide a method for recycling plastic substrates that can remove the coating in a simple manner and easily remove the coating layer from the plastic substrate, and that does not discolor the alkaline solution used to remove the coating after the removal process.
In addition, it is preferable that the coating can be easily detached from the substrate, but that the coating is firmly attached to the substrate before the detachment process. Therefore, the coating is required to have high adhesion to the substrate. In addition, it is preferable that the coating has excellent abrasion resistance. In other words, it is desired that the coating formed on the substrate has good toughness, excellent adhesion to the substrate, and abrasion resistance.
If the coating has excellent toughness, it can be applied not only to printed matter in the form of reverse printing (lamination) printing as in Patent Documents 7 to 9, which require two types of substrates and have a printed layer between the substrates, but also to printed matter in the form of front printing, in which a substrate is disposed on only one side of the printed layer.

Therefore, in order to simultaneously solve the above-mentioned marine plastic problem and the problems posed to worker health and the environment, and for suitable use in printed matter in the form of surface printing, the present invention aims to provide a film-forming material (film-forming composition) that can be used to detach a film from general-purpose plastic substrates in a simple manner, can easily remove a film layer from the plastic substrate, prevents discoloration of the alkaline solution after detachment, and can form a film that has excellent adhesion to the substrate, excellent abrasion resistance, and good toughness.

As a result of extensive research into solving the above problems, the inventors discovered that the above problems could be solved by adding an acrylic resin having specific acid values and hydroxyl values, and exhibiting a specific glass transition temperature, to a film-forming composition, and thus completed the present invention.

That is, the present invention includes the following aspects.
[1] A removable film-forming composition for forming a film that is removable by treatment with an alkaline solution on the surface of a substrate A directly or via another layer, the film-forming composition comprising an acrylic resin having an acid value of 10 to 100 mg KOH/g, a hydroxyl value of 1 mg KOH/g or more, and a glass transition temperature of 30 to 130° C.
[2] The film-forming composition according to [1], which contains a wax.
[3] The film-forming composition according to [1] or [2], which contains an organic solvent.
[4] The film-forming composition according to [3], which contains at least one organic solvent selected from the group consisting of n-propyl acetate, isopropyl alcohol, and a cyclic ester compound having 4 to 10 carbon atoms.
[5] The film-forming composition according to any one of [1] to [4], further comprising a colorant.
[6] The film-forming composition according to [5], which is used as a printing ink.
[7] The film-forming composition according to any one of [1] to [4], which is used as a primer or a varnish.
[8] A printed matter having a coating made of the coating composition according to any one of [1] to [7], provided on the surface of a substrate A directly or via another layer.
[9] The printed matter described in [8], wherein the coating is at least one selected from a printing layer, a primer layer, and a varnish layer.
[10] The printed matter according to [8] or [9], in which no substrate is arranged on the surface opposite to the surface on which the substrate A is arranged with respect to the coating.
[11] A method for producing a recycled substrate A, comprising treating the printed matter according to any one of [8] to [10] with an alkaline solution to remove the coating from the substrate A.

The present invention provides a film-forming composition that can be used to remove a film from a general-purpose plastic substrate in a simple manner, can easily remove the film layer from the plastic substrate, and can form a film that prevents discoloration of the alkaline solution after removal, has excellent adhesion to the substrate, is excellent in abrasion resistance, and has good toughness.

The present invention will be described in detail below. Note that the explanation of the components described below is merely an example for explaining the present invention, and the present invention is not limited to these contents.

(Film-forming composition)
The film-forming composition of the present invention is used to form a film on the surface of the substrate A directly or via another layer. In the present invention, the other layer may be a single layer or a plurality of layers. The film formed by the film-forming composition of the present invention can be removed by treatment with an alkaline solution. The film-forming composition contains an acrylic resin. The acrylic resin has an acid value of 10 to 100 mgKOH/g, a hydroxyl value of 1 mgKOH/g or more, and a glass transition temperature of 30 to 130°C. As described above, the acrylic resin has a specific acid value, hydroxyl value, and glass transition point, which, in combination, allow the film to be removed by a simple method, the film layer to be easily removed from the plastic substrate, and coloring of the alkaline solution after removal can be prevented. Furthermore, a film having excellent adhesion to the substrate and excellent abrasion resistance and good toughness can also be formed.

Here, in this specification, "having an acid value" means that when the acid value of the acrylic resin is measured by the neutralization titration method of JIS K 0070 (1992), titration with one drop does not reach the end point.
Moreover, "having a hydroxyl value" means that when the hydroxyl value of the acrylic resin is measured by the neutralization titration method of JIS K 0070 (1992), titration with one drop does not reach the end point.

The film formed from the film-forming composition of the present invention is used to remove from the substrate A a printed layer that has been formed on the surface of the substrate A directly or via another layer.
Here, the printed layer refers to a layer formed by printing with printing ink.
Methods for removing the printed layer from the substrate A include, for example, a method in which the printed layer itself has a detachment function and the printed layer is detached from the substrate A (hereinafter also referred to as the pattern A method), and a method in which a separate layer is provided between the printed layer and the substrate A, the separate layer has a detachment function, and the printed layer is also detached from the substrate A by detaching the separate layer (hereinafter also referred to as the pattern B method).

The film formed from the film-forming composition of the present invention includes both the printed layer in the method of pattern A and another layer in the method of pattern B. More specifically, the film according to the present invention includes both the printed layer and the primer layer and varnish layer described below.
That is, the film-forming composition of the present invention can be used in any of the forms of printing ink, primer, and varnish.
The film-forming composition of the present invention may be used to form at least one of a printed layer, a primer layer, and a varnish layer, and one or more of these layers may be formed using the film-forming composition of the present invention.

The film and the substrate A according to the present invention may be arranged as follows, for example.
・Base material A - Printed layer (white) - Printed layer (color)
Substrate A - primer layer - printed layer (white) - printed layer (color)
・Base material A - Printed layer (white) - Printed layer (color) - Varnish layer ・Base material A - Primer layer - Printed layer (white) - Printed layer (color) - Varnish layer ・Base material A - Printed layer (color) - Printed layer (white)
Substrate A - primer layer - printed layer (color) - printed layer (white)
・Substrate A - Printed layer (color) - Printed layer (white) - Varnish layer ・Substrate A - Primer layer - Printed layer (color) - Printed layer (white) - Varnish layer ・Substrate A - Varnish layer ・Substrate A - Printed layer (color)
・Substrate A - Printing layer (white)

Here, substrate A refers to substrate A described later, printed layer (white) refers to a printed layer formed by printing the film-forming composition of the present invention as a printing ink and using a colorant used in white ink as a colorant to be contained in the film-forming composition, printed layer (color) refers to a printed layer formed by printing the film-forming composition of the present invention as a printing ink and using a colorant other than the colorant used in white ink as a colorant to be contained in the film-forming composition, primer layer refers to a layer formed using the film-forming composition of the present invention as a primer described later, and varnish layer refers to a layer formed using the film-forming composition of the present invention as a varnish described later.
In the above example, the printing layer is formed by laminating two layers, one using white ink and the other using a color ink as a colorant other than white ink. However, the printing layer does not have to be formed of two or more layers in this manner, and may be formed of a single layer of either white or color.

<Organic Solvent-Based Composition>
The organic solvent-based composition, which is the film-forming composition of the present invention, is used to form a printed layer that is detached by treatment with an alkaline solution directly or via another layer on the surface of the substrate A. The organic solvent-based composition contains an acrylic resin.
The organic solvent-based composition contains an organic solvent, and optionally contains a colorant and other components.
The organic solvent-based composition may use a raw material derived from biomass. Due to problems such as the depletion of petroleum resources, it is preferable that petroleum-derived products are replaced by those produced using plants as alternative energy sources and/or those produced using microorganisms, etc. In that case, the organic solvent-based composition can contribute to reducing the environmental load by being carbon neutral.

<<Acrylic resin>>
The acrylic resin has an acid value.
The acid value of the acrylic resin is 10 to 100 mgKOH/g. If the acid value of the acrylic resin is 10 mgKOH/g or more, the coating can be easily detached from the substrate, and if the acid value is 100 mgKOH/g or less, coloring of the alkaline solution after detachment can be effectively prevented.
The acid value of the acrylic resin is preferably from 10 to 100 mgKOH/g, and more preferably from 30 to 70 mgKOH/g.

The acrylic resin has a hydroxyl value.
The hydroxyl value of the acrylic resin is 1 mgKOH/g or more from the viewpoints of achieving a balance with the acid value, enabling easy detachment of the coating from the substrate, and effectively preventing coloration of the alkaline solution after detachment.
The hydroxyl value of the acrylic resin is preferably from 1 to 300 mgKOH/g, and more preferably from 30 to 200 mgKOH/g.

The glass transition temperature of the acrylic resin is 30 to 130°C.
When the glass transition temperature is within the above range, the coating can be given appropriate strength of the film surface and elasticity against breakage.When the glass transition temperature is 30°C or higher, the coating film becomes too soft, and the problems of reduced adhesion and reduced friction resistance can be effectively prevented.On the other hand, when the glass transition temperature is 130°C or lower, the coating film is not too hard, and the surface friction resistance can be kept good, and the strength against film breakage can be maintained, so that the adhesion can be kept good.
Furthermore, when the glass transition temperature is within the above range, a coating that is excellent not only in abrasion resistance but also in water abrasion resistance can be formed.
The glass transition temperature of the acrylic resin is preferably from 40 to 110°C, and more preferably from 50 to 90°C.

The weight average molecular weight of the acrylic resin is preferably 2,000 to 100,000 from the viewpoint of achieving both releasability and adhesion to the substrate.
The weight average molecular weight of the acrylic resin can be determined by gel permeation chromatography (GPC).

The acrylic resin is a resin obtained by polymerizing a (meth)acrylic monomer. When the acrylic resin is used as the sole binder resin, the acrylic resin must have a carboxyl group, and is preferably an acrylic resin obtained by polymerizing a monomer containing a (meth)acrylic monomer having a carboxyl group, such as (meth)acrylic acid or maleic acid.
Alternatively, a monomer containing a (meth)acrylic monomer having a functional group, such as 2-hydroxyethyl (meth)acrylate or glycidyl (meth)acrylate, can be polymerized, and after polymerization, the functional group can be reacted with a compound having a carboxyl group and reactive with the functional group (such as maleic anhydride), thereby providing the acrylic resin with a carboxyl group.
Examples of monomers other than the (meth)acrylic monomer having a carboxyl group include (meth)acrylic monomers such as methyl (meth)acrylate and butyl (meth)acrylate;
Examples of the vinyl monomer include maleic acid, maleic anhydride, styrene, vinyl acetate, butadiene, and acrylonitrile.
The acrylic resin may be used as an aqueous resin after neutralization reaction. The aqueous resin may be in the form of an emulsion or a solution.

The content of the acrylic resin in the composition of the present invention, in terms of solid content relative to the total mass of the composition, is preferably 1% by mass or more, more preferably 2% by mass or more, even more preferably 3% by mass or more, and particularly preferably 5% by mass or more, and is preferably 50% by mass or less, more preferably 40% by mass or less, even more preferably 30% by mass or less, and particularly preferably 25% by mass or less, with any combination of these upper and lower limits being used.
The content of the acrylic resin in the composition is preferably 1 to 50 mass%, more preferably 2 to 40 mass%, further preferably 3 to 30 mass%, and particularly preferably 5 to 25 mass%, in terms of solid content relative to the total mass of the composition.
Within the above range, when a film is formed from the composition of the present invention, excellent adhesion to a substrate and appropriate viscosity as a composition can be obtained, and the working efficiency during production and film formation is good.

<<Organic solvent>>
The organic solvent is not particularly limited, and examples thereof include various organic solvents such as aromatic hydrocarbons such as toluene, xylene, Solvesso #100, Solvesso #150, etc.; aliphatic hydrocarbons such as hexane, methylcyclohexane, heptane, octane, decane, etc.; esters such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, amyl acetate, ethyl formate, butyl propionate, etc.; and cyclic ester compounds such as γ-butyrolactone having 4 carbon atoms, δ-valerolactone having 5 carbon atoms, ε-caprolactone having 6 carbon atoms, oxilican-2-one having 7 carbon atoms, η-caprylolactone having 8 carbon atoms, oxecan-2-one having 9 carbon atoms, and oxacycloundecan-2-one having 10 carbon atoms. Examples of water-miscible organic solvents include various organic solvents such as alcohols, such as methanol, ethanol, propanol, butanol, and isopropyl alcohol, ketones, such as acetone, methyl ethyl ketone, and cyclohexanone, and glycol ethers, such as ethylene glycol (mono, di) methyl ether, 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, and dipropylene glycol (mono, di) methyl ether. These can be used alone or in combination of two or more.

It is more preferable that the ester-based organic solvent contains an ester-based organic solvent having 4 or more carbon atoms in order to prevent the plate drying of the organic solvent-based composition of the present invention due to its high volatility. The ester-based organic solvent having 4 or more carbon atoms is not limited, but ethyl acetate, isopropyl acetate, n-propyl acetate, and butyl acetate are more preferable, and n-propyl acetate is particularly preferable.

In the present invention, the organic solvent preferably contains at least one of n-propyl acetate, isopropyl alcohol, and a cyclic ester compound having 4 to 10 carbon atoms.
In particular, when the organic solvent-based composition contains a cyclic ester compound having 4 to 10 carbon atoms, a coating that exhibits excellent adhesion to shrinkable substrates can be formed.

The content of the ester-based organic solvent in the organic solvent-based composition of the present invention is preferably 1 to 60% by mass, preferably 3 to 55% by mass, preferably 5 to 50% by mass, preferably 7 to 45% by mass, preferably 10 to 40% by mass, preferably 12 to 35% by mass, preferably 15 to 30% by mass, preferably 18 to 28% by mass, preferably 20 to 25% by mass, and preferably 20 to 23% by mass.

When the organic solvent-based composition of the present invention is used for gravure ink applications, it is preferable that it does not contain an aromatic hydrocarbon organic solvent, and contains an alcohol having a specific evaporation rate of 100 or less, where the evaporation rate of butyl acetate is taken as 100. By containing an alcohol having a specific evaporation rate of 100 or less, it is possible to maintain highlight transferability with a dot area of 10% or less, and to maintain highlight improvement. The mechanism for this is as follows:
1) After the organic solvent-based composition of the present invention is transferred to the substrate, half of the organic solvent-based composition of the present invention remains in the cells of the gravure plate.
2) The solvent contained in the remaining organic solvent-based composition of the present invention evaporates until it comes into contact with the organic solvent-based composition of the present invention in the ink pan again, and the composition becomes semi-dry. Furthermore, since the solvent with the faster evaporation rate evaporates first, the solvent with the slower evaporation rate remains in the ink pan.
3) At this time, if any solvent having high resin solubility remains, the semi-dried composition will re-dissolve when it comes into contact with the organic solvent-based composition of the present invention again, thereby preventing the organic solvent-based composition of the present invention from solidifying in the cells.
With general-purpose alcohols, the specific evaporation rate of which exceeds 100 when the evaporation rate of butyl acetate is taken as 100, is high, so the above-mentioned mechanism tends to be difficult to function.

Secondly, alcohols with a specific evaporation rate of 100 or less, when the evaporation rate of butyl acetate is taken as 100, have a low ratio of hydroxyl groups (alcohol groups) per alcohol molecule, and therefore tend to increase the solubility of acrylic resins.
From the viewpoints of both operational hygiene during printing and harmfulness of packaging materials, it is more preferable to use ethyl acetate, normal propyl acetate, isopropanol, normal propanol, etc., and not to use aromatic solvents such as toluene or ketone-based solvents such as methyl ethyl ketone.
Among them, from the viewpoint of solubility in acrylic resin and soluble nitrocellulose, a mixture of isopropyl alcohol/normal propyl acetate/γ-butyrolactone is more preferable. In order to adjust the dryness, glycol ethers can be added in an amount of less than 10% by mass of the total composition.

<<Coloring Agent>>
The organic solvent-based composition of the present invention may further contain a colorant.

The colorant used in the organic solvent-based composition of the present invention may be an inorganic pigment, an organic pigment or a dye that is generally used in inks, paints, recording materials and the like.
Examples of organic pigments include soluble azo pigments, insoluble azo pigments, azo pigments, phthalocyanine pigments, halogenated phthalocyanine pigments, anthraquinone pigments, anthanthrone pigments, dianthraquinonyl pigments, anthrapyrimidine pigments, perylene pigments, perinone pigments, quinacridone pigments, thioindigo pigments, dioxazine pigments, isoindolinone pigments, quinophthalone pigments, azomethine azo pigments, flavanthrone pigments, diketopyrrolopyrrole pigments, isoindoline pigments, indanthrone pigments, and carbon black pigments. In addition, examples of the pigments include carmine 6B, lake red C, permanent red 2B, disazo yellow, pyrazolone orange, carmine FB, chromophthal yellow, chromophthal red, phthalocyanine blue, phthalocyanine green, dioxazine violet, quinacridone magenta, quinacridone red, indanthrone blue, pyrimidine yellow, thioindigo bordeaux, thioindigo magenta, perylene red, perinone orange, isoindolinone yellow, aniline black, diketopyrrolopyrrole red, and daylight fluorescent pigments. In addition, both non-acid-treated pigments and acid-treated pigments can be used. Specific examples of preferred organic pigments are listed below.

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

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

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

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

Examples of purple pigments include C.I. Pigment Violet 1, C.I. Pigment Violet 2, C.I. Pigment Violet 3, C.I. Pigment Violet 3:1, C.I. Pigment Violet 3:3, C.I. Pigment Violet 5:1, C.I. Pigment Violet 13, C.I. Pigment Violet 19 (γ type, β type), C.I. Pigment Violet 23, C.I. Pigment Violet 25, C.I. Pigment Violet 27, C.I. Pigment Violet 29, C.I. Pigment Violet 31, C.I. Pigment Violet 32, C.I. Pigment Violet 36, C.I. Pigment Violet 37, C.I. Examples of suitable pigments include C.I. Pigment Violet 38, C.I. Pigment Violet 42, C.I. Pigment Violet 50, and the like.

Examples of yellow pigments include C.I. Pigment Yellow 1, C.I. Pigment Yellow 3, C.I. Pigment Yellow 12, C.I. Pigment Yellow 13, C.I. Pigment Yellow 14, Pigment Yellow 17, C.I. Pigment Yellow 24, C.I. Pigment Yellow 42, C.I. Pigment Yellow 55, C.I. Pigment Yellow 62, C.I. Pigment Yellow 65, C.I. Pigment Yellow 74, C.I. Pigment Yellow 83, C.I. Pigment Yellow 86, C.I. Pigment Yellow 93, C.I. Pigment Yellow 94, C.I. Pigment Yellow 95, C.I. Pigment Yellow 109, C.I. Pigment Yellow 110, C.I. Pigment Yellow 117, C.I. Pigment Yellow 120, C.I. Pigment Yellow 125, C.I. Pigment Yellow 128, C.I. Pigment Yellow 129, C.I. Pigment Yellow 137, C.I. Pigment Yellow 138, C.I. Pigment Yellow 139, C.I. Pigment Yellow 147, C.I. Pigment Yellow 148, C.I. Pigment Yellow 150, C.I. Pigment Yellow 151, C.I. Pigment Yellow 153, C.I. Pigment Yellow 154, C.I. Pigment Yellow 155, C.I. Pigment Yellow 166, C.I. Pigment Yellow 168, C.I. Pigment Yellow 174, C.I. Pigment Yellow 180, C.I. Pigment Yellow 185 and C.I. Pigment Yellow 213.

Examples of orange pigments include C.I. Pigment Orange 5, C.I. Pigment Orange 13, C.I. Pigment Orange 16, C.I. Pigment Orange 34, C.I. Pigment Orange 36, C.I. Pigment Orange 37, C.I. Pigment Orange 38, C.I. Pigment Orange 43, C.I. Pigment Orange 51, C.I. Pigment Range 55, C.I. Pigment Orange 59, C.I. Pigment Orange 61, C.I. Pigment Orange 64, C.I. Pigment Orange 71, and C.I. Pigment Orange 74.

Examples of brown pigments include C.I. Pigment Brown 23, C.I. Pigment Brown 25, and C.I. Pigment Brown 26.
Among them, preferred pigments include C.I. Pigment Black 7 as a black pigment, C.I. Pigment Blue 15, C.I. Pigment Blue 15:1, C.I. Pigment Blue 15:2, C.I. Pigment Blue 15:3, C.I. Pigment Blue 15:4, and C.I. Pigment Blue 15:6 as indigo pigments, C.I. Pigment Green 7 as a green pigment, and C.I. Pigment Red 57:1, C.I. Pigment Red 48:1, C.I. Pigment Red 48:2, C.I. Pigment Red 48:3, C.I. Pigment Red 146, C.I. Pigment Red 242, C.I. Pigment Red 185, and C.I. Examples of the pigments include C.I. Pigment Red 122, C.I. Pigment Red 178, C.I. Pigment Red 149, C.I. Pigment Red 144, C.I. Pigment Red 166, purple pigments include C.I. Pigment Violet 23, C.I. Pigment Violet 37, yellow pigments include C.I. Pigment Yellow 83, C.I. Pigment Yellow 14, C.I. Pigment Yellow 180, C.I. Pigment Yellow 139, orange pigments include C.I. Pigment Orange 38, C.I. Pigment Orange 13, C.I. Pigment Orange 34, C.I. Pigment Orange 64, and the like. It is preferable to use at least one or more selected from these groups.

Inorganic pigments include carbon black, titanium oxide, red ocher, aluminum, mica, zinc oxide, barium sulfate, calcium carbonate, and silica. Also usable are glittering pigments (Metashine; Nippon Sheet Glass Co., Ltd.) made of glass flakes or clumped flakes as a base material coated with a metal or metal oxide. From the standpoint of cost and coloring power, it is preferable to use carbon black for black ink, titanium oxide for white ink, aluminum for gold and silver ink, and mica for pearl ink.

The total pigment content is preferably 1 mass% or more and preferably 60 mass% or less of the total amount of the organic solvent-based composition of the present invention, from the viewpoint of ensuring the concentration and coloring power of the organic solvent-based composition of the present invention.

<<Other ingredients>>
The organic solvent-based composition of the present invention may further contain other components such as a binder resin and an auxiliary.
Examples of the binder resin include cellulose-based resins, urethane resins, polyamide resins, vinyl chloride-vinyl acetate copolymer resins, ketone resins, polyester resins, (meth)acrylic resins, rosin-modified maleic acid resins and rosin-modified fumaric acid resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, alkyd resins, polyvinyl chloride resins, cyclized rubber, chlorinated rubber, butyral resins, and petroleum resins, as well as polymerizable monomers having a carboxyl group such as itaconic acid, maleic acid, fumaric acid, cinnamic acid, or anhydrides thereof, polymerizable monomers having a sulfonic acid group such as sulfonated styrene, and polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide. Examples of the binder resin include radical copolymers such as (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-(anhydride)maleic acid resins, and terpene-(anhydride)maleic acid resins, and acid-modified polyolefin resins, which can be used singly or in combination. When the organic solvent-based composition contains a (meth)acrylic resin and/or a styrene-(meth)acrylic resin as a binder resin, the content of the above <<acrylic resin>> includes the content of the (meth)acrylic resin and/or the styrene-(meth)acrylic resin in this item.

Examples of auxiliary agents that can be used as appropriate include waxes such as paraffin wax, polyethylene wax, polypropylene wax, carnauba wax, candelilla wax, montan wax, microcrystalline wax, amide wax, and modified montan wax to impart abrasion resistance and slipperiness; fatty acid amide compounds such as oleic acid amide, stearic acid amide, and erucic acid amide; silicone and non-silicon antifoaming agents to suppress foaming during printing; and dispersants. Nonionic dispersants are preferred as dispersants.

When a wax is used as an auxiliary agent, the wax content is, in terms of solid content in the total amount of the organic solvent-based composition, preferably 0.1% by mass or more in lower limit, and preferably 5.0% by mass or less in upper limit, more preferably 4.0% by mass or less, and even more preferably 3.0% by mass or less. Any combination of these upper and lower limits may be used.

The acid value of the dispersant is preferably 30 mgKOH/g or less, more preferably 25 mgKOH/g or less, and even more preferably 20 mgKOH/g or less. It may also be, for example, 1 mgKOH/g or more, or even 3 mgKOH/g or more.

The content of the dispersant is preferably 1 part by mass or more, more preferably 2 parts by mass or more, more preferably 5 parts by mass or more, more preferably 10 parts by mass or more, more preferably 15 parts by mass or more, more preferably 20 parts by mass or more, and is preferably 100 parts by mass or less, more preferably 80 parts by mass or less, more preferably 75 parts by mass or less, more preferably 70 parts by mass or less, more preferably 65 parts by mass or less, and more preferably 60 parts by mass or less, relative to 100 parts by mass of the colorant.

In addition to the above, water, wetting agents, adhesive aids, leveling agents, antistatic agents, viscosity modifiers, metal chelates, trapping agents, antiblocking agents, isocyanate-based curing agents, and silane coupling agents can also be used as necessary. The viscosity of the organic solvent-based composition of the present invention, as measured at 25°C using a Zahn Cup #3 manufactured by Rigo Co., Ltd., is preferably 6 seconds or more, more preferably 10 seconds or more, and even more preferably 13 seconds or more. It is also preferably 25 seconds or less, more preferably 20 seconds or less, and even more preferably 18 seconds or less.

The surface tension of the organic solvent-based composition of the present invention is preferably 25 mN/m or more, more preferably 33 mN/m or more. Also, it is preferably 50 mN/m or less, more preferably 43 mN/m or less. By appropriately increasing the surface tension of the organic solvent-based composition of the present invention, it is possible to suppress dot bridging (a stain on the printing surface in which adjacent dots in a halftone dot portion are connected to each other) while maintaining the wettability of the organic solvent-based composition of the present invention to the substrate, and by appropriately lowering the surface tension of the organic solvent-based composition of the present invention, it is possible to increase the wettability of the organic solvent-based composition of the present invention to the substrate and suppress repelling.

When the organic solvent-based composition of the present invention is used for gravure printing or flexographic printing, it can be produced using an Eiger mill, sand mill, bead mill, gamma mill, attritor, etc., which are commonly used in the production of gravure or flexographic inks.

When preparing the organic solvent-based composition of the present invention, from the standpoint of uniformity, a preliminary composition (kneaded base ink) may be prepared by previously mixing at least a portion of the acrylic resin, a colorant, and at least a portion of the organic solvent.

Although resist ink is an example of a composition that is removed from a substrate as in the present invention, the resist ink is intended to remove the coating from the substrate in advance, leaving only a portion of it, in order to process the substrate. The use and purpose of this resist ink is fundamentally different from that of the coating-forming composition of the present invention, which is intended to remove the entire coating and recycle the substrate, and therefore does not fall under the well-known technology of the present invention.

The film-forming composition of the present invention can also be used as a primer composition to form a primer layer.

<Primer Composition>
When the film-forming composition of the present invention is used to form a primer layer, the film-forming composition of the present invention, that is, the primer composition, contains the above-mentioned <<acrylic resin>>.
The primer composition may contain, in addition to the acrylic resin, a commercially available binder resin, a solvent such as an organic solvent or an aqueous solvent, additives, and the like, without any particular limitation.

Examples of binder resins include cellulose resins, urethane resins, polyamide resins, vinyl chloride-vinyl acetate copolymer resins, ketone resins, polyester resins, (meth)acrylic resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, alkyd resins, polyvinyl chloride resins, cyclized rubber, chlorinated rubber, butyral resins, and petroleum resins; and radical copolymers such as (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-maleic acid (anhydride) resins, and terpene-maleic acid (anhydride) resins, which are copolymerized with polymerizable monomers such as polymerizable monomers having a carboxyl group, such as itaconic acid, maleic acid, fumaric acid, cinnamic acid, or acid anhydrides thereof, polymerizable monomers having a sulfonic acid group, such as sulfonated styrene, and polymerizable monomers having a sulfonamide group, such as vinylbenzenesulfonamide; and acid-modified polyolefin resins, which may be used singly or in combination. When a (meth)acrylic resin and/or a styrene-(meth)acrylic resin is contained as a binder resin, the content of the above <<acrylic resin>> includes the content of the (meth)acrylic resin and/or the styrene-(meth)acrylic resin in this item.

The solvent may be any organic solvent, for example, an organic solvent similar to those described in the "Organic Solvent" section of the "Organic Solvent-Based Composition" above can be used.

Additives include extender pigments, pigment dispersants, leveling agents, defoamers, waxes, plasticizers, anti-blocking agents, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc.

When the primer layer contains the above-mentioned acrylic resin, the amount of acrylic resin added may be determined appropriately within a range that does not impair the properties of the primer layer, but it is preferable that the amount be in the range of 5 to 30% by weight, for example, relative to the total weight of the primer layer composition.

In addition, a primer to which a resin having an acidic group or a low molecular weight compound has been added can also be preferably used. There are no particular limitations on the resin having an acidic group or the low molecular weight compound that can be used as long as it can be easily mixed with the above-mentioned acrylic resin, which is the main component of the primer, or with an organic solvent, etc.

Examples of the resin having an acidic group include cellulose resins, urethane resins, polyamide resins, vinyl chloride-vinyl acetate copolymer resins, ketone resins, polyester resins, (meth)acrylic resins, rosin-modified maleic acid resins and rosin-modified fumaric acid resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, alkyd resins, polyvinyl chloride resins, cyclized rubbers, chlorinated rubbers, butyral resins, and petroleum resins to which an acid value has been imparted; polymerizable monomers having an acidic group, such as itaconic acid, maleic acid, fumaric acid, cinnamic acid, or acid anhydrides thereof, polymerizable monomers having a carboxyl group, such as sulfonated styrene, polymerizable monomers having a sulfonamide group, such as vinylbenzenesulfonamide; and radical copolymers such as (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-maleic acid (anhydride) resins, and terpene-maleic acid (anhydride) resins; and acid-modified polyolefin resins (excluding the binder resins). These may be used singly or in combination. When a (meth)acrylic resin and/or a styrene-(meth)acrylic resin is contained as a resin having an acidic group, the content of the above <<acrylic resin>> includes the content of the (meth)acrylic resin and/or the styrene-(meth)acrylic resin in this item.

Preferred examples of low molecular weight compounds having an acidic group include organic acids such as saturated fatty acids, unsaturated fatty acids, hydroxy acids, aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids, oxocarboxylic acids, and carboxylic acid derivatives, and these can be used singly or in combination.
Examples of saturated fatty acids include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, decanoic acid, undecanoic acid, and dodecanoic acid. Examples of unsaturated fatty acids include oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and sorbic acid. Examples of hydroxy acids include lactic acid, malic acid, and citric acid. Examples of aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, and ketone. Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, undecane diacid, dodecane diacid, dimer acid, fumaric acid, maleic acid, azelaic acid, etc. Examples of the tricarboxylic acid include aconitic acid and trimer acid, etc. Examples of the oxocarboxylic acid include pyruvic acid and oxaloacetic acid, etc. Examples of the carboxylic acid derivative include amino acid and nitrocarboxylic acid, and these can be used singly or in combination. In addition, citric acid, butyric acid, caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, eleostearic acid, arachidic acid, sebacic acid, etc. can comply with the so-called Swiss Ordinance, and it is preferable to use substances that comply with various regulations.

The film-forming composition of the present invention can also be used as a varnish composition for forming a varnish layer.

<Varnish Composition>
When the film-forming composition of the present invention is used to form a varnish layer, the film-forming composition of the present invention, that is, the varnish composition, contains the above-mentioned <<acrylic resin>>.

In addition to the acrylic resin, the varnish composition may contain, without particular limitation, commercially available binder resins, solvents such as organic solvents and aqueous solvents, additives, etc.

Examples of binder resins include cellulose resins, urethane resins, polyamide resins, vinyl chloride-vinyl acetate copolymer resins, ketone resins, polyester resins, (meth)acrylic resins, rosin-modified maleic acid resins, rosin-modified fumaric acid resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, alkyd resins, polyvinyl chloride resins, cyclized rubber, chlorinated rubber, butyral resins, and petroleum resins; and radical copolymers such as (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-maleic acid (anhydride) resins, and terpene-maleic acid (anhydride) resins, which are copolymerized with polymerizable monomers such as polymerizable monomers having a carboxyl group, such as itaconic acid, maleic acid, fumaric acid, cinnamic acid, or acid anhydrides thereof, polymerizable monomers having a sulfonic acid group, such as sulfonated styrene, and polymerizable monomers having a sulfonamide group, such as vinylbenzenesulfonamide; and acid-modified polyolefin resins, which may be used singly or in combination. When a (meth)acrylic resin and/or a styrene-(meth)acrylic resin is contained as a binder resin, the content of the above <<acrylic resin>> includes the content of the (meth)acrylic resin and/or the styrene-(meth)acrylic resin in this item.

The solvent may be any organic solvent, for example, the same organic solvents as those described in the "Organic Solvent" section of the "Organic Solvent-Based Composition" above can be used.

Additives include extender pigments, pigment dispersants, leveling agents, defoamers, waxes, plasticizers, anti-blocking agents, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc.

When the varnish layer contains the above-mentioned acrylic resin, the amount of acrylic resin added may be determined appropriately within a range that does not impair the properties of the varnish layer, but it is preferable that the amount be in the range of 5 to 30% by weight of the varnish layer composition, for example.

Varnishes to which resins having acidic groups or low molecular weight compounds have been added can also be preferably used. There are no particular limitations on the resins having acidic groups or low molecular weight compounds that can be used as long as they can be easily mixed with the acrylic resins and organic solvents that are the main components of the varnish.

Examples of the resin having an acidic group include cellulose resins, urethane resins, polyamide resins, vinyl chloride-vinyl acetate copolymer resins, ketone resins, polyester resins, (meth)acrylic resins, rosin-modified maleic acid resins and rosin-modified fumaric acid resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, alkyd resins, polyvinyl chloride resins, cyclized rubbers, chlorinated rubbers, butyral resins, and petroleum resins to which an acid value has been imparted; polymerizable monomers having an acidic group, such as itaconic acid, maleic acid, fumaric acid, cinnamic acid, or acid anhydrides thereof, polymerizable monomers having a carboxyl group, such as sulfonated styrene, polymerizable monomers having a sulfonamide group, such as vinylbenzenesulfonamide; and radical copolymers such as (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-maleic acid (anhydride) resins, and terpene-maleic acid (anhydride) resins; and acid-modified polyolefin resins (excluding the binder resins). These may be used singly or in combination. When a (meth)acrylic resin and/or a styrene-(meth)acrylic resin is contained as a resin having an acidic group, the content of the above <<acrylic resin>> includes the content of the (meth)acrylic resin and/or the styrene-(meth)acrylic resin in this item.

Preferred examples of low molecular weight compounds having an acidic group include organic acids such as saturated fatty acids, unsaturated fatty acids, hydroxy acids, aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids, oxocarboxylic acids, and carboxylic acid derivatives, and these can be used singly or in combination.

Saturated fatty acids include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, decanoic acid, undecanoic acid, and dodecanoic acid. Unsaturated fatty acids include oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, and sorbic acid. Hydroxy acids include lactic acid, malic acid, and citric acid. Aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, and ketone. Examples of the dicarboxylic acid include oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, sebacic acid, undecane diacid, dodecane diacid, dimer acid, fumaric acid, maleic acid, azelaic acid, etc. Examples of the tricarboxylic acid include aconitic acid and trimer acid, etc. Examples of the oxocarboxylic acid include pyruvic acid and oxaloacetic acid, etc. Examples of the carboxylic acid derivative include amino acid and nitrocarboxylic acid, and these can be used singly or in combination. In addition, citric acid, butyric acid, caproic acid, enanthic acid, caprylic acid, capric acid, lauric acid, myristic acid, palmitic acid, palmitoleic acid, stearic acid, oleic acid, linoleic acid, eleostearic acid, arachidic acid, sebacic acid, etc. can comply with the so-called Swiss Ordinance, and it is preferable to use substances that comply with various regulations.

(Printing on substrate)
The film-forming composition of the present invention has excellent adhesion to various substrates and can be used for printing on paper, synthetic paper, cloth, thermoplastic resin films, plastic products, steel plates, etc., and is useful as an ink for gravure printing using a gravure printing plate by electronic engraving intaglio, etc., or for flexographic printing using a flexographic printing plate by a resin plate, etc., but can also be used for an inkjet method in which ink is discharged from an inkjet nozzle without using a plate, but this is not preferred. That is, in the case of inkjet ink, ink droplets discharged from a nozzle directly adhere to a substrate to form a printed matter, whereas in the case of the film-forming composition of the present invention, the printing ink is once adhered to and transferred to a printing plate or a printing pattern, and then only the ink is again adhered to a substrate and dried as necessary to form a printed matter.

The thickness of the printing ink formed by the gravure printing method or the flexographic printing method using the film-forming composition of the present invention is, for example, preferably 10 μm or less, and more preferably 5 μm or less.

(Printed matter and laminate)
A printed matter having a film can be obtained by printing the film-forming composition of the present invention on the surface of the substrate A directly or via another layer.
As will be shown in the examples below, the coating according to the present invention has excellent adhesion to the substrate, excellent abrasion resistance, and good toughness.
Therefore, the film according to the present invention can be preferably applied to a printed matter in the form of surface printing in which a substrate is arranged only on one side of the printed layer (i.e., no substrate is arranged on the side opposite to the side on which the substrate A is arranged with respect to the film). The film according to the present invention can also be applied to a printed matter in the form of back printing (lamination) printing in which the substrate B is arranged on the film side of the printed matter and the printed layer is arranged between the substrates, that is, two types of substrates are essential, but it is more preferable to apply it to a printed matter in the form of surface printing as described above. A printed matter in the form of surface printing does not require multiple substrates compared to a printed matter in the form of back printing (lamination) printing, and is therefore convenient because it has a simple configuration, but the film is required to have toughness. The film according to the present invention has excellent toughness and can be applied to a printed matter in the form of surface printing.
The embodiment of the printed matter printed using the film-forming composition of the present invention and the laminate constructed using the printed matter are not limited, but preferred examples include the following surface printing embodiments.

As described above, the mode in which a coating is formed on the surface of the substrate A directly or via another layer is as follows.
<Surface printing>
・Base material A - Printed layer (white) - Printed layer (color)
Substrate A - primer layer - printed layer (white) - printed layer (color)
・Base material A - Printed layer (white) - Printed layer (color) - Varnish layer ・Base material A - Primer layer - Printed layer (white) - Printed layer (color) - Varnish layer ・Base material A - Printed layer (color) - Printed layer (white)
Substrate A - primer layer - printed layer (color) - printed layer (white)
・Substrate A - Printed layer (color) - Printed layer (white) - Varnish layer ・Substrate A - Primer layer - Printed layer (color) - Printed layer (white) - Varnish layer ・Substrate A - Varnish layer ・Substrate A - Printed layer (color)
・Substrate A - Printing layer (white)

The printing layer (white), the printing layer (color), the primer layer, and the varnish layer are as described above.
The substrate A will be described below.

<Substrate A>
The substrate A is preferably a plastic substrate, and examples thereof include polyamide resins such as nylon 6, nylon 66, and nylon 46; polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, and polybutylene naphthalate; biodegradable resins such as polyhydroxycarboxylic acids such as polylactic acid, aliphatic polyester resins such as poly(ethylene succinate) and poly(butylene succinate); polyolefin resins such as polypropylene and polyethylene, polyimide resins, polyarylate resins, and mixtures thereof; and thermoplastic resins such as films and laminates thereof. Among these, films and laminates made of polyester, polyamide, polyethylene, and polypropylene are preferably used, and polypropylene or polyethylene is more preferable when the release property of the film-forming composition of the present invention is considered. These substrate films may be unstretched or stretched films, and the manufacturing method thereof is not limited. The thickness of the substrate film is also not particularly limited, but it is usually sufficient to be in the range of 1 to 500 μm.

It is preferable that the printing surface of substrate A has been subjected to a corona discharge treatment, and silica, alumina, etc. may be vapor-deposited onto it.

The substrate A, the printed layer (white), the printed layer (color), the primer layer, or the varnish layer in the laminate may each have a barrier layer interposed therebetween. Examples of the barrier layer include an inorganic vapor deposition layer and a barrier coat layer, and these may be used alone or in combination.

The inorganic vapor deposition layer is a layer having gas barrier properties that prevent the permeation of oxygen gas and water vapor gas, and is a vapor deposition layer made of an inorganic substance or an inorganic oxide. Examples of inorganic substances or inorganic oxides include aluminum, alumina, silica, etc., and these can be used alone or in combination of two or more. Two or more inorganic vapor deposition layers may be provided. When two or more inorganic vapor deposition layers are provided, they may have the same composition or different compositions.

The barrier coat layer protects the inorganic vapor deposition layer and can improve the gas barrier properties against oxygen, water vapor, etc. Such a gas barrier coat layer is formed from a resin composition such as a hydrolyzate of a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by the sol-gel method in the presence of a sol-gel catalyst and a solvent such as water or an organic solvent, or a hydrolysis polycondensation product of a metal alkoxide.

(Method of removing coating from substrate A)
In the present invention, the coating film is removed from the substrate A by treating the printed matter with an alkaline solution, thereby producing a recycled substrate A.

The removal process includes a step of immersing the printed matter or laminate in an alkaline solution while heating and stirring at 20 to 90°C or ultrasonically vibrating it. Heating and stirring and ultrasonic vibration may be performed simultaneously. The heating temperature is preferably 30°C or higher, more preferably 40°C or higher, more preferably 50°C or higher, and more preferably 60°C or higher, and it is more preferable to perform heating and stirring and ultrasonic vibration simultaneously.

The alkaline solution used in the desorption step is not limited, but preferably has a pH of 9 or higher, and is preferably an aqueous solution of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium dihydrogen carbonate, potassium dihydrogen carbonate, etc. The aqueous solutions of sodium hydroxide, potassium hydroxide, sodium bicarbonate, potassium bicarbonate, sodium dihydrogen carbonate, potassium dihydrogen carbonate, etc. are preferably aqueous solutions with a concentration of 0.5% to 10% by mass, more preferably 1% to 5% by mass.

The alkaline solution may also contain a water-soluble organic solvent.
Examples of the water-soluble organic solvent include methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, ethylene glycol monomethyl ether (methyl cellosolve), ethylene glycol monoethyl ether (cellosolve), ethylene glycol monobutyl ether (butyl cellosolve), ethylene glycol dibutyl ether, diethylene glycol monomethyl ether (methyl carbitol), diethylene glycol dimethyl ether, diethylene glycol monoethyl ether (carbitol), diethylene glycol diethyl ether (diethyl carbitol), diethylene glycol monobutyl ether (butyl carbitol), diethylene glycol dibutyl ether, and triethylene glycol. Examples include cholesteryl monomethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, methylene dimethyl ether (methylal), propylene glycol monobutyl ether, tetrahydrofuran, acetone, diacetone alcohol, acetonylacetone, acetylacetone, ethylene glycol monomethyl ether acetate (methyl cellosolve acetate), diethylene glycol monomethyl ether acetate (methyl carbitol acetate), diethylene glycol monoethyl ether acetate (carbitol acetate), ethyl hydroxyisobutyrate, and ethyl lactate, which may be used alone or in combination of two or more.

The content of the water-soluble organic solvent in the alkaline solution is preferably 0.1% by mass to 20% by mass, and more preferably 1% by mass to 10% by mass.
The alkaline solution may also contain a water-insoluble organic solvent.
Specific examples of the water-insoluble organic solvent include alcohol-based solvents such as n-butanol, 2-butanol, isobutanol, and octanol; aliphatic hydrocarbon-based solvents such as hexane, heptane, and normal paraffin; aromatic hydrocarbon-based solvents such as benzene, toluene, xylene, and alkylbenzene; halogenated hydrocarbon-based solvents such as methylene chloride, 1-chlorobutane, 2-chlorobutane, 3-chlorobutane, and carbon tetrachloride; ester-based solvents such as methyl acetate, ethyl acetate, and butyl acetate; ketone-based solvents such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; and ether-based solvents such as ethyl ether and butyl ether. These may be used alone or in combination of two or more.

The alkaline solution may also contain a surfactant. Examples of the surfactant include various anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. Among these, anionic surfactants, nonionic surfactants, and amphoteric surfactants are preferred.

Examples of anionic surfactants include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfate ester salts of higher fatty acid esters, sulfonates of higher fatty acid esters, sulfate ester salts and sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, and the like. Specific examples of these include dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenylsulfonate, and dibutylphenylphenol disulfonate.

Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene sorbitol fatty acid esters, glycerin fatty acid esters, polyoxyethylene glycerin fatty acid esters, polyglycerin fatty acid esters, sucrose fatty acid esters, polyoxyethylene alkylamines, polyoxyethylene fatty acid amides, fatty acid alkylol amides, alkyl alkanol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, polyethylene glycol polypropylene glycol block copolymers, and the like. Of these, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylol amides, acetylene glycol, oxyethylene adducts of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymers are preferred.

Other surfactants that can be used include silicone-based surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; and biosurfactants such as spiculisporic acid, rhamnolipids, and lysolecithin.

These surfactants can be used alone or in combination of two or more. When a surfactant is added, the amount added is preferably in the range of 0.001 to 2% by mass, more preferably 0.001 to 1.5% by mass, and even more preferably 0.01 to 1% by mass, based on the total amount of the alkaline solution.

The target printed matter or laminate is immersed in the alkaline solution, for example in a treatment tank, while the alkaline solution is heated to 20 to 90°C or ultrasonically vibrated. There are no particular limitations on the heating method, and known heating methods using heat rays, infrared rays, microwaves, etc. can be used. Ultrasonic vibration can be achieved, for example, by attaching an ultrasonic vibrator to the treatment tank and applying ultrasonic vibration to the warm water or alkaline solution.

It is also preferable that the alkaline solution is stirred during immersion. Examples of stirring methods include mechanical stirring of the dispersion of the printed matter or laminate contained in the treatment tank using a stirring blade, water flow stirring using a water flow pump, and bubbling with an inert gas such as nitrogen gas. These methods may be used in combination to achieve efficient peeling.

The time for which the printed matter or laminate is immersed in the alkaline solution varies depending on the composition of the printed matter, but is generally in the range of 2 minutes to 48 hours. In the present invention, it is not necessary for 100% of the coating on the printed matter to be completely detached from the substrate, but it is preferable for 60% or more of the 100% by weight of the coating to be detached, more preferably 70% or more, even more preferably 80% or more, and particularly preferably 90% or more.

In the desorption process, the film may be immersed in the alkaline solution once or several times. That is, the film may be immersed once and then the separated film substrate may be recovered, or the film may be immersed several times and then the film substrate may be recovered. When the film is immersed multiple times in the desorption process, the concentration of the alkaline solution may be changed. During the desorption process, known processes such as washing with water and drying may be added as appropriate.

The film-forming composition of the present invention keeps the content of solvents that are harmful to health and the environment below a certain level, while maintaining the same properties for general-purpose plastic substrates as conventional film-forming materials. Furthermore, because it contains a specific acrylic resin, it can be easily detached by treatment with an alkaline solution, and the film layer can be easily removed from the plastic substrate. In addition, it prevents discoloration of the alkaline solution after detachment, and can form a film that has excellent adhesion to the substrate, excellent abrasion resistance, and good toughness.

The contents and effects of the present invention will be explained in more detail below with reference to examples, but the present invention is not limited to these. Note that the "parts" and "%" shown below are all based on mass.

<Hydroxyl value measurement method>
The hydroxyl value was measured in accordance with JIS K 0070-1992.

<Acid value measurement method>
The acid value was measured in accordance with JIS K 0070-1992.

The components of the binder resin (acrylic resin and other binder resins other than acrylic resin), colorant (pigment), organic solvent, and auxiliary (wax) used in the following examples and comparative examples are as follows:

<Binder resin>
Resin 1: Acrylic resin (acid value in solid content: 15 mg KOH/g, hydroxyl value 200 mg KOH/g, glass transition temperature 30° C., solid content 50 parts by mass)
Resin 2: Acrylic resin (acid value in solid content: 30 mg KOH/g, hydroxyl value 150 mg KOH/g, glass transition temperature 50° C., solid content 50 parts by mass)
Resin 3: Acrylic resin (acid value in solid content: 45 mg KOH/g, hydroxyl value 100 mg KOH/g, glass transition temperature 70° C., solid content 50 parts by mass)
Resin 4: Acrylic resin (acid value in solid content: 60 mg KOH/g, hydroxyl value: 50 mg KOH/g, glass transition temperature: 90° C., solid content: 50 parts by mass)
Resin 5: Acrylic resin (acid value in solid content: 90 mg KOH/g, hydroxyl value 10 mg KOH/g, glass transition temperature 110° C., solid content 50 parts by mass)
Resin 6: Acrylic resin (acid value in solid content: 5 mg KOH/g, hydroxyl value 50 mg KOH/g, glass transition temperature 70° C., solid content 50 parts by mass)
Resin 7: Acrylic resin (acid value in solid content: 110 mg KOH/g, hydroxyl value 50 mg KOH/g, glass transition temperature 20° C., solid content 50 parts by mass)
Resin 8: Acrylic resin (acid value in solid content: 50 mg KOH/g, hydroxyl value 150 mg KOH/g, glass transition temperature 135° C., solid content 50 parts by mass)
Resin 9: Industrial nitrocellulose H1/2 solution (nitrocellulose, 70% solids, 9.0-14.9% viscosity at 25.0% solution concentration according to JIS K-6703, Taihei Chemical Products Co., Ltd., adjusted to 50% solids with IPA)
Resin 10: Vinyl chloride/vinyl acetate copolymer resin (resin monomer composition by mass: vinyl chloride/vinyl acetate/vinyl alcohol = 92/3/5, hydroxyl value (mgKOH/g) = 70)

<Pigments>
White: titanium oxide pigment (JR600A (manufactured by Teika Co., Ltd.))
Indigo: Phthalocyanine indigo pigment (FASTOGEN BLUE LA5380 indigo pigment (manufactured by DIC Corporation))

<Organic Solvent>
Isopropyl alcohol (IPA)
n-Propyl acetate γ-Butyl lactone

<Wax>
Polyethylene wax: Excelex 20700 manufactured by Mitsui Chemicals

Example 1
30 parts of isopropyl alcohol, 15 parts of N-propyl acetate (normal propyl acetate), 1 part of polyethylene wax, 1 part of γ-butyl lactone, and 50 parts of acrylic resin 1 were mixed together to obtain a mixture.
To 100 parts of the obtained mixture, 35% IPA/EtAc mixed solvent (isopropyl alcohol/ethyl acetate=50/50 (parts/parts)) was added so that the temperature was about 15 seconds (25° C.) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.) to prepare a film-forming composition.

The composition of each component of the film-forming composition of Example 1 is shown in Table 1 below. The physical properties of the acrylic resin in the film-forming composition of Example 1 are also shown in Table 1.

The prepared film-forming compositions were subjected to the following evaluations. The evaluation results are shown in Table 2 below.

<Evaluation item 1: Adhesion to substrate>
The prepared film-forming composition was used to print a solid pattern of 240 mm length x 80 mm width on substrate A using bar coater #4, and then dried with a dryer to form printed layer 1, obtaining a printed matter of configuration 1 below.
<<Composition of printed matter>>
・Structure 1: Base material A-printing layer 1
Substrate A: Corona-treated polyethylene terephthalate film (Toyobo Co., Ltd., Ester E5100, thickness 12 μm) (PET)
Substrate B: Biaxial polypropylene film (Toyobo Co., Ltd., Pylen P2161, thickness 20 μm) (OPP)
Substrate C: Polystyrene film (DXL-270-41S, manufactured by Mitsubishi Chemical Corporation, thickness 40 μm) (OPS)

The resulting print was either immediately or left for 24 hours, after which 5 cm of cellophane tape (12 mm width, made by Nichiban) was applied to the printed surface, and one end of the cellophane tape was quickly pulled off perpendicular to the printed surface. The remaining percentage of the printed film was then visually evaluated based on the area ratio.

[Evaluation Criteria]
5: The printing film does not peel off at all.
4: 80% or more of the printed film remained on the film.
3: 50% or more but less than 80% of the printed film remained on the film.
2: Less than 50% of the printed coating remained on the film.
1: When applying cellophane tape, the printed film peels off from the film onto the cellophane tape.

<Evaluation item 2: Abrasion resistance>
The prepared film-forming composition was used to print a solid pattern of 240 mm length x 80 mm width on substrate A using bar coater #4, and then dried with a dryer to form printed layer 1, obtaining a printed matter of configuration 1 below.
<<Composition of printed matter>>
・Structure 1: Base material A-printing layer 1
Substrate A: Corona-treated polyethylene terephthalate film (Toyobo Co., Ltd., Ester E5100, thickness 12 μm) (PET)
Substrate B: Biaxial polypropylene film (Toyobo Co., Ltd., Pylen P2161, thickness 20 μm) (OPP)
Substrate C: Polystyrene film (DXL-270-41S, manufactured by Mitsubishi Chemical Corporation, thickness 40 μm) (OPS)

The resulting prints were rubbed on the printed surface using high-quality paper and evaluated using a commercially available Gakushin-type rub fastness tester, with 100 strokes back and forth at a load of 500 g. A rating of 4 or higher is considered to be within the practical range.

[Evaluation Criteria]
5: No change to the printed surface or the pad.
4: There is no change in the printed surface, but the patch cloth is discolored.
3: Streaky scratches are observed on the printed surface.
2: Thick streaky scratches are observed on the printed surface.
1: Surface scratches are observed on the printed surface.

<Evaluation item 3: Peelability>
The prepared film-forming composition was used to print a solid pattern of 240 mm length x 80 mm width on substrate A using bar coater #4, and then dried with a dryer to form printed layer 1, obtaining a printed matter of configuration 1 below.
<<Composition of printed matter>>
・Structure 1: Base material A-printing layer 1
Substrate A: Corona-treated polyethylene terephthalate film (Ester E5100, manufactured by Toyobo Co., Ltd., thickness 12 μm) (PET)

<<Alkaline solution>>
A peeling test was carried out under each of the following conditions, and the ease of peeling under each condition was compared.
Condition 1: 1.5 mass% sodium hydroxide aqueous solution, 50°C
Condition 2: 1.5 mass% sodium hydroxide aqueous solution, 85°C

<<Peel test conditions>>
The peeling test was performed for 15 minutes under each condition, and evaluation was performed. If peeling occurred within 5 minutes of treatment, it indicates fairly high performance.
The printed matter was cut into a test piece of 20 mm x 20 mm, which was then immersed in the solution and stirred with a stirrer. After checking the state of peeling after stirring, the printed matter was rubbed with a finger to see if the coating film would peel off due to rubbing.
The peelability of the ink coating film under the above conditions was evaluated according to the following evaluation criteria.

[Evaluation Criteria]
5: Ink film detachment confirmed after stirring for less than 5 minutes. Complete detachment when rubbed 4: Ink film detachment confirmed after stirring for 15 minutes. Complete detachment when rubbed 3: Ink film not detached confirmed after stirring for 15 minutes. Complete detachment when rubbed 2: Ink film detachment not confirmed after stirring for 15 minutes. Partial detachment when rubbed 1: Ink film detachment not confirmed after stirring for 15 minutes. No detachment confirmed even when rubbed

<Evaluation item 4: Contamination with cleaning fluid>
The color difference between the cleaning solution after the peeling test performed under each of the test conditions 1 and 2 in the above <Evaluation item 3: peelability> and a 1.5 mass% aqueous solution of sodium hydroxide was measured using a spectrophotometric color/haze meter COH7700 (manufactured by Nippon Denshoku Industries Co., Ltd.) and evaluated according to the following evaluation criteria.

[Evaluation Criteria]
5: ΔE 0.0 or more and less than 1.0 4: ΔE 1.0 or more and less than 2.0 3: ΔE 2.0 or more and less than 4.0 2: ΔE 4.0 or more and less than 7.0 1: ΔE 7.0 or more

Example 2
40 parts of isopropyl alcohol, 20 parts of N-propyl acetate (normal propyl acetate), 10 parts of indigo pigment, 1 part of polyethylene wax, 1 part of γ-butyl lactone, and 40 parts of acrylic resin 1 were mixed to obtain a mixture.
To 100 parts of the obtained mixture, 35% IPA/EtAc mixed solvent (isopropyl alcohol/ethyl acetate=50/50 (parts/parts)) was added so that the temperature was about 15 seconds (25° C.) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.) to prepare a film-forming composition.

The prepared film-forming composition was evaluated in the same manner as in Example 1.
The composition of the film-forming composition and the evaluation results are shown in Tables 1 and 2 below.

Example 3
A film-forming composition was prepared in the same manner as in Example 1, except that the composition of the film-forming composition in Example 1 was changed to the composition shown in Table 1 below.
The prepared film-forming composition was evaluated in the same manner as in Example 1.
The composition of the film-forming composition and the evaluation results are shown in Tables 1 and 2 below.

Example 4
40 parts of isopropyl alcohol, 20 parts of N-propyl acetate, 10 parts of indigo pigment, 10 parts of nitrocellulose varnish, 1 part of polyethylene wax, 1 part of γ-butyl lactone, and 25 parts of acrylic resin 1 were mixed to obtain a mixture.
To 100 parts of the obtained mixture, 35% IPA/EtAc mixed solvent (isopropyl alcohol/ethyl acetate=50/50 (parts/parts)) was added so that the temperature was about 15 seconds (25° C.) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.) to prepare a film-forming composition.

The prepared film-forming composition was evaluated in the same manner as in Example 1.
The composition of the film-forming composition and the evaluation results are shown in Tables 1 and 2 below.

(Examples 5 to 7, Reference Example 8, Examples 9 to 11)
A film-forming composition was prepared in the same manner as in Examples 1 and 4, except that the composition of the film-forming composition in Example 1 was changed to the composition shown in Table 1 below.
The prepared film-forming composition was evaluated in the same manner as in Example 1.
The composition of the film-forming composition and the evaluation results are shown in Tables 1 and 2 below.

(Comparative Examples 1 to 6)
A film-forming composition was prepared in the same manner as in Examples 1 and 4, except that the composition of the film-forming composition in Example 1 was changed to the composition shown in Table 1 below.
The prepared film-forming composition was evaluated in the same manner as in Example 1.
The composition of the film-forming composition and the evaluation results are shown in Tables 1 and 2 below.

From the above, it can be seen that by using the film-forming composition of the present invention, it is possible to form a film that can be easily removed by treatment with an alkaline solution and that allows the film layer to be easily removed from the plastic substrate, and it is also possible to form a film that prevents discoloration of the alkaline solution after removal, has excellent adhesion to the substrate, is excellent in abrasion resistance, and has good toughness.

Claims (9)

A composition for forming a removable film for forming a film that is removable by treatment with an alkaline solution on the surface of a substrate A directly or via another layer, comprising:
The film-forming composition contains an acrylic resin, a wax, and an organic solvent,
The acrylic resin has an acid value of 10 to 100 mgKOH/g, a hydroxyl value of 50 mgKOH/g or more and 200 mgKOH/g or less , and a glass transition temperature of 30 to 90° C .;
The wax is contained in an amount of 0.1 to 5% by mass in terms of solid content,
The film-forming composition, wherein the organic solvent contains a cyclic ester compound having at least 4 to 10 carbon atoms. The film-forming composition according to claim 1, wherein the organic solvent further contains at least one of n-propyl acetate and isopropyl alcohol. The film-forming composition according to claim 1, which contains a colorant. The film-forming composition according to claim 3, which is used as a printing ink. The film-forming composition according to claim 1, which is used as a primer or varnish. A printed matter having a film made of the film-forming composition according to any one of claims 1 to 5, directly or via another layer on the surface of substrate A. The printed matter according to claim 6, wherein the coating is at least one selected from a printing layer, a primer layer, and a varnish layer. The printed matter according to claim 6, in which no substrate is disposed on the surface opposite to the surface on which the substrate A is disposed with respect to the coating. A method for producing a recycled substrate A obtained by treating the printed matter described in claim 6 with an alkaline solution to remove the coating from the substrate A.