Composition for forming removable film

Abstract

The present invention provides a composition for forming a coating film, the composition being capable of forming a coating film that exhibits excellent adhesion to a base material, while having excellent friction resistance and good toughness, the coating film being removed from common plastic base materials by a simple method, enabling a coating film layer to be easily separated from a plastic base material, and preventing coloring of an alkaline solution after the removal.　This composition for forming a removable coating film is used for the purpose of forming a coating film, which is removed by a treatment with an alkaline solution, directly on the surface of a base material A or with another layer being interposed therebetween. This composition for forming a coating film contains an acrylic resin which 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.

Description

[Technical field]

[0001] The present invention relates to compositions used to form removable coatings from substrates. [Background technology]

[0002] In recent years, the marine plastic problem caused by plastics discarded or dumped in the ocean being broken down in seawater and broken down into microplastics (microplasticization) has become evident. 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. In addition, 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 materials out of consideration for their impact on worker health and the environment. Therefore, materials that solve the above issues must be developed with this in mind.

[0003] 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 placed 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 consideration 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 that use urethane resins with acid values ​​as binder resins have also been disclosed (Patent Document 4, Patent Document 5, and Patent Document 6). However, when a urethane resin with an acid value is used as the main binder resin, it is expected that the adhesion to the substrate will be insufficient, and imparting an acid value to the urethane resin will increase the viscosity of the resin, making it necessary to use the above-mentioned solvents that have a large impact on health and the environment to adjust the viscosity, or avoiding the coexistence of amine values ​​and acid values ​​to reduce viscosity, resulting in reduced suitability for lamination applications, and other problems remain before the ink can be used universally as a material from which a film can be detached.

[0004] 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 to release each substrate (Patent Document 7, Patent Document 8, and Patent Document 9). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent No. 3822738 [Patent Document 2] Patent No. 4653913 [Patent Document 3] Patent No. 4451071 [Patent Document 4] Patent No. 6638802 [Patent Document 5] Patent No. 6631964 [Patent Document 6] JP 2020-169280 A [Patent Document 7] Patent Publication No. 2021-98294 [Patent Document 8] Patent Publication No. 2021-98295 [Patent Document 9] Patent Publication No. 2021-98546 Summary of the Invention [Problem to be solved by the invention]

[0006] However, it has been found that when attempting to remove the coating using 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 problems of environmental pollution and will increase the cost of treating the waste liquid, 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 above, which requires two types of substrates and has a printed layer between the substrates, but also to printed matter in the form of front printing, in which a substrate is placed on only one side of the printed layer.

[0007] Therefore, in order to simultaneously solve the above-mentioned marine plastic problem and the problems posed to worker health and the environment, and to be suitably used in printed matter in the form of surface printing, it is an object of the present invention to provide a film-forming material (film-forming composition) that can be used to detach a film from a general-purpose plastic substrate by a simple method, that can easily remove a coating layer from the plastic substrate, that prevents discoloration of the alkaline solution after detachment, and that can form a coating that has excellent adhesion to the substrate, excellent abrasion resistance, and good toughness. [Means for solving the problem]

[0008] As a result of intensive research into solving the above problems, the inventors have found that the above problems can be solved by adding an acrylic resin having specific acid values ​​and hydroxyl values, and exhibiting a specific glass transition temperature, to a coating-forming composition, and have thus completed the present invention.

[0009] 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], which contains 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], applied directly or via another layer to the surface of a substrate A. [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 described in [8] or [9], wherein no substrate is arranged on the side opposite to the side 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. Effect of the Invention

[0010] The present invention can provide a coating-forming composition that can detach a coating from a general-purpose plastic substrate in a simple manner, can easily remove a coating layer from the plastic substrate, and can form a coating that prevents discoloration of the alkaline solution after detachment, has excellent adhesion to the substrate, is excellent in abrasion resistance, and has good toughness. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The present invention will be described in detail below. Note that the following description of the constituent elements is merely an example for explaining the present invention, and the present invention is not limited to the contents thereof.

[0012] (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 multiple 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 be formed.

[0013] 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. In addition, "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.

[0014] 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).

[0015] 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.

[0016] The film and the substrate A according to the present invention may be arranged, for example, as follows. · Substrate A-Printed layer (white)-Printed layer (color) · Substrate A-Primer layer-Printed layer (white)-Printed layer (color) · Substrate A - Printed layer (white) - Printed layer (color) - Varnish layer · Substrate A-Primer layer-Printed layer (white)-Printed layer (color)-Varnish layer · Substrate 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 - Printing layer (color) ·Substrate A-printing layer (white)

[0017] 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.

[0018] <Organic Solvent-Based Composition> The organic solvent-based composition, which is a 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.

[0019] <<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.

[0020] 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.

[0021] 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 film surface strength and elasticity against breakage. When the glass transition temperature is 30°C or higher, the coating film becomes too soft, which effectively prevents problems such as reduced adhesion and reduced abrasion resistance. On the other hand, when the glass transition temperature is 130°C or lower, the coating film is not too hard, and the surface abrasion resistance is kept good, and further, 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.

[0022] 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).

[0023] 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 that has a carboxyl group and reacts with the functional group (such as maleic anhydride), thereby imparting a carboxyl group to the acrylic resin. 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.

[0024] The content of the acrylic resin in the composition of the present invention, calculated as 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 %, particularly preferably 5 to 25 mass %, calculated as solid content based on 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.

[0025] <<Organic solvents>> 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, oxalican-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.

[0026] From the viewpoint of preventing drying of the organic solvent-based composition of the present invention due to its high volatility, it is more preferable to contain an ester-based organic solvent having 4 or more carbon atoms. The ester-based organic solvent having 4 or more carbon atoms is not limited, but is more preferably ethyl acetate, isopropyl acetate, n-propyl acetate, or butyl acetate, and particularly preferably n-propyl acetate.

[0027] 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.

[0028] The content of the ester-based organic solvent in the organic solvent-based composition of the present invention is preferably 1 to 60 mass%, preferably 3 to 55 mass%, preferably 5 to 50 mass%, preferably 7 to 45 mass%, preferably 10 to 40 mass%, preferably 12 to 35 mass%, preferably 15 to 30 mass%, preferably 18 to 28 mass%, preferably 20 to 25 mass%, and preferably 20 to 23 mass%.

[0029] 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 with 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. The evaporation rate of common alcohols is so fast that the specific evaporation rate exceeds 100 when the evaporation rate of butyl acetate is taken as 100, making it difficult for the above mechanism to function.

[0030] 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 work 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 addition, glycol ethers can be added in an amount of less than 10% by mass of the total composition to adjust the dryness.

[0031] <<Coloring agent>> The organic solvent-based composition of the present invention may further contain a colorant.

[0032] 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, for example, 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, daylight fluorescent pigments, etc. can be mentioned. In addition, both non-acid-treated pigments and acid-treated pigments can be used. Specific examples of preferred organic pigments are given below.

[0033] Examples of black pigments include CI Pigment Black 1, CI Pigment Black 6, CI Pigment Black 7, CI Pigment Black 9, and CI Pigment Black 20.

[0034] Examples of indigo pigments include CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4, CI Pigment Blue 15:5, CI Pigment Blue 15:6, CI Pigment Blue 16, CI Pigment Blue 17:1, CI Pigment Blue 22, CI Pigment Blue 24:1, CI Pigment Blue 25, CI Pigment Blue 26, CI Pigment Blue 60, CI Pigment Blue 61, CI Pigment Blue 62, CI Pigment Blue 63, CI Pigment Blue 64, CI Pigment Blue 75, CI Pigment Blue 79, and CI Pigment Blue 80.

[0035] Examples of green pigments include CI Pigment Green 1, CI Pigment Green 4, CI Pigment Green 7, CI Pigment Green 8, CI Pigment Green 10, and CI Pigment Green 36.

[0036] Examples of red pigments include CI Pigment Red 1, CI Pigment Red 2, CI Pigment Red 3, CI Pigment Red 4, CI Pigment Red 5, CI Pigment Red 6, CI Pigment Red 7, CI Pigment Red 8, CI Pigment Red 9, CI Pigment Red 10, CI Pigment Red 11, CI Pigment Red 12, CI Pigment Red 15, CI Pigment Red 16, CI Pigment Red 17, CI Pigment Red 18, CI Pigment Red 19, CI Pigment Red 20, CI Pigment Red 21, CI Pigment Red 22, CI Pigment Red 23, CI Pigment Red 24, CI Pigment Red 25, CI Pigment Red 26, CI Pigment Red 27, CI Pigment Red 28, CI Pigment Red 29, CI Pigment Red 30, CI Pigment Red 31, CI Pigment Red 32, CI Pigment Red 33, CI Pigment Red 34, CI Pigment Red 35, CI Pigment Red 36, CI Pigment Red 37, CI Pigment Red 38, CI Pigment Red 39, CI Pigment Red 40, CI Pigment Red 41, CI Pigment Red 42, CI Pigment Red 43, CI Pigment Red 44, CI Pigment Red 45, CI Pigment Red 46, CI Pigment Red 47, CI Pigment Red 48, CI Pigment Red 49, CI Pigment Red 50, CI Pigment Red 51, CI Pigment Red 52, CI Pigment Red 53, CI Pig Red 19, CI Pigment Red 20, CI Pigment Red 21, CI Pigment Red 22, CI Pigment Red 23, CI Pigment Red 31, CI Pigment Red 32, CI Pigment Red 38, CI Pigment Red 41, CI Pigment Red 43, CI Pigment Red 46, CI Pigment Red 48, CI Pigment Red 48:1, CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 48:4, CI Pigment Red 48:5, CI Pigment Red 48:6, CI Pigment Red 49, CI Pigment Red 49:1, CI Pigment Red 49:2, CI Pigment Red 49:3, CI Pigment Red 52, CI Pigment Red 52:1, CI Pigment Red 52:2, CI Pigment Red 53, CI Pigment Red 53:1, CI Pigment Red 53:2, CI Pigment Red 53:3, CI Pigment Red 54, CI Pigment Red 57, CI Pigment Red 57: 1, CI Pigment Red 58, CI Pigment Red 58:1, CI Pigment Red 58:2, CI Pigment Red 58:3, CI Pigment Red 58:4, CI Pigment Red 60:1, CI Pigment Red 63, CI Pigment Red 63:1, CI Pigment Red 63:2, CI Pigment Red 63:3, CI Pigment Red 64:1, CI Pigment Red 68, CI Pigment Red 81:1, CI Pigment Red 83, CI Pigment Red 88, C.I. Pigment Red 89, CI Pigment Red 95, CI Pigment Red 112, CI Pigment Red 114, CI Pigment Red 119, CI Pigment Red 122, CI Pigment Red 123, CI Pigment Red 136, CI Pigment Red 144, CI Pigment Red 146, CI Pigment Red 147, CI Pigment Red 149, CI Pigment Red 150, CI Pigment Red 164, CI Pigment Red 166, CI Pigment Red 168, CI Pigment Red 169, CI Pigment Red 170, CI Pigment Red 171, C I Pigment Red 172, CI Pigment Red 175, CI Pigment Red 176, CI Pigment Red 177, CI Pigment Red 178, CI Pigment Red 179, CI Pigment Red 180, CI Pigment Red 181, CI Pigment Red 182, CI Pigment Red 183, CI Pigment Red 184, CI Pigment Red 185, CI Pigment Red 187, CI Pigment Red 188, CI Pigment Red 190, CI Pigment Red 192, CI Pigment Red 193, CI Pigment Red 194, CI Pigment Red 200,. CI Pigment Red 202, CI Pigment Red 206, CI Pigment Red 207, CI Pigment Red 208, CI Pigment Red 209, CI Pigment Red 210, CI Pigment Red 211, CI Pigment Red 213, CI Pigment Red 214, CI Pigment Red 215, CI Pigment Red 216, CI Pigment Red 220, CI Pigment Red 221, CI Pigment Red 223, CI Pigment Red 224, CI Pigment Red 226, CI Pigment Red 237, CI Pigment Red 238, CI Pigment Red 239, CI Pigment Red 240, CI Pigment Red 242, CI Pigment Red 243, CI Pigment Red 244, CI Pigment Red 245, CI Pigment Red 246, CI Pigment Red 247, CI Pigment Red 248, CI Pigment Red 249, CI Pigment Red 250, CI Pigment Red 251, CI Pigment Red 252, CI Pigment Red 253, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 256, CI Pigment Red 257, CI Pigment Red 258, CI Pigment Red 259, CI Pigment Red 260, CI Pigment Red 261, CI Pigment Red 262, CI Pigment Red 263, CI Pigment Red 264, CI Pigment Red 265, CI Pigment Red 266, CI Pigment Red 267, CI Pigment Examples of pigments that may be used include CI Pigment Red 245, CI Pigment Red 247, CI Pigment Red 248, CI Pigment Red 251, CI Pigment Red 253, CI Pigment Red 254, CI Pigment Red 255, CI Pigment Red 256, CI Pigment Red 257, CI Pigment Red 258, CI Pigment Red 260, CI Pigment Red 262, CI Pigment Red 263, CI Pigment Red 264, CI Pigment Red 266, CI Pigment Red 268, CI Pigment Red 269, CI Pigment Red 270, CI Pigment Red 271, CI Pigment Red 272, CI Pigment Red 279, and the like.

[0037] Examples of purple pigments include CI Pigment Violet 1, CI Pigment Violet 2, CI Pigment Violet 3, CI Pigment Violet 3:1, CI Pigment Violet 3:3, CI Pigment Violet 5:1, CI Pigment Violet 13, CI Pigment Violet 19 (γ type, β type), CI Pigment Violet 23, CI Pigment Violet 25, CI Pigment Violet 27, CI Pigment Violet 29, CI Pigment Violet 31, CI Pigment Violet 32, CI Pigment Violet 36, CI Pigment Violet 37, CI Pigment Violet 38, CI Pigment Violet 42, and CI Pigment Violet 50.

[0038] Examples of yellow pigments include CI Pigment Yellow 1, CI Pigment Yellow 3, CI Pigment Yellow 12, CI Pigment Yellow 13, CI Pigment Yellow 14, Pigment Yellow 17, CI Pigment Yellow 24, CI Pigment Yellow 42, CI Pigment Yellow 55, CI Pigment Yellow 62, CI Pigment Yellow 65, CI Pigment Yellow 74, CI Pigment Yellow 83, CI Pigment Yellow 86, CI Pigment Yellow 93, CI Pigment Yellow 94, CI Pigment Yellow 95, CI Pigment Yellow 109, CI Pigment Yellow 110, CI Pigment Yellow 117, CI Pigment Yellow 120, CI Pigment Yellow 122, CI Pigment Yellow 124, CI Pigment Yellow 126, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 130, CI Pigment Yellow 131, CI Pigment Yellow 132, CI Pigment Yellow 133, CI Pigment Yellow 134, CI Pigment Yellow 135, CI Pigment Yellow 136, CI Pigment Yellow 137, CI Pigment Yellow 138, CI Pigment Yellow 139, CI Pigment Yellow 140, CI Pigment Yellow 141, CI Pigment Yellow 142, CI Pigment Yellow 143, CI Pigment Yellow 144, CI Pigment Yellow 145, CI Pigment Yellow 146, CI Pigment Yellow 147, CI Pigment Yellow 148, CI Pigment Yellow 149, CI Pigment Yellow 150, CI Pigment Yellow 15 Rho 120, CI Pigment Yellow 125, CI Pigment Yellow 128, CI Pigment Yellow 129, CI Pigment Yellow 137, CI Pigment Yellow 138, CI Pigment Yellow 139, CI Pigment Yellow 147, CI Pigment Yellow 148, CI Pigment Yellow 150, CI Pigment Yellow 151, CI Pigment Yellow 153, CI Pigment Yellow 154, CI Pigment Yellow 155, CI Pigment Yellow 166, CI Pigment Yellow 168, CI Pigment Yellow 174, CI Pigment Yellow 180, CI Pigment Yellow 185 and CI Pigment Yellow 213.

[0039] Examples of orange pigments include CI Pigment Orange 5, CI Pigment Orange 13, CI Pigment Orange 16, CI Pigment Orange 34, CI Pigment Orange 36, CI Pigment Orange 37, CI Pigment Orange 38, CI Pigment Orange 43, CI Pigment Orange 51, CI Pigment Range 55, CI Pigment Orange 59, CI Pigment Orange 61, CI Pigment Orange 64, CI Pigment Orange 71, and CI Pigment Orange 74.

[0040] Examples of brown pigments include CI Pigment Brown 23, CI Pigment Brown 25, and CI Pigment Brown 26. Among them, preferred pigments include CI Pigment Black 7 as a black pigment, CI Pigment Blue 15, CI Pigment Blue 15:1, CI Pigment Blue 15:2, CI Pigment Blue 15:3, CI Pigment Blue 15:4, and CI Pigment Blue 15:6 as indigo pigments, CI Pigment Green 7 as a green pigment, and CI Pigment Red 57:1, CI Pigment Red 48:1, CI Pigment Red 48:2, CI Pigment Red 48:3, CI Pigment Red 146, CI Pigment Red 242, CI Pigment Red 185, and CI Pigment Red 12 as red pigments. Examples of pigments that can be used include CI Pigment Red 2, CI Pigment Red 178, CI Pigment Red 149, CI Pigment Red 144, CI Pigment Red 166, purple pigments such as CI Pigment Violet 23 and CI Pigment Violet 37, yellow pigments such as CI Pigment Yellow 83, CI Pigment Yellow 14, CI Pigment Yellow 180, CI Pigment Yellow 139, and orange pigments such as CI Pigment Orange 38, CI Pigment Orange 13, CI Pigment Orange 34, and CI Pigment Orange 64. It is preferable to use at least one or more pigments selected from these groups.

[0041] Examples of inorganic pigments include carbon black, titanium oxide, red iron oxide, aluminum, mica, zinc oxide, barium sulfate, calcium carbonate, and silica. Also usable is a glittering pigment (Metashine; Nippon Sheet Glass Co., Ltd.) made of glass flakes or clumped flakes as a base material and 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.

[0042] From the viewpoint of ensuring the concentration and coloring power of the organic solvent-based composition of the present invention, the total content of the pigments 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.

[0043] <<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, 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. These may 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 <<acrylic resin>> above includes the content of the (meth)acrylic resin and / or the styrene-(meth)acrylic resin in this item.

[0044] Examples of the auxiliary that can be used appropriately include waxes such as paraffin wax, polyethylene wax, polypropylene wax, carnauba wax, candelilla wax, montan wax, microcrystalline wax, amide wax, and modified montan wax for imparting friction 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 for suppressing foaming during printing, and dispersants. As the dispersant, a nonionic dispersant is preferred.

[0045] When a wax is used as an auxiliary, the wax content is preferably 0.1% by mass or more in terms of solid content in the total amount of the organic solvent-based composition, and the lower limit is preferably 5.0% by mass or less, 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 can be used.

[0046] 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, and may be, for example, 1 mgKOH / g or more, or even 3 mgKOH / g or more.

[0047] 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, and more preferably 20 parts by mass or more, relative to 100 parts by mass of the colorant, 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.

[0048] In addition to the above, water, wetting agents, adhesive assistants, 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 is preferably 6 seconds or more, more preferably 10 seconds or more, and even more preferably 13 seconds or more, as measured at 25°C using a Zahn Cup #3 manufactured by Rigo Co., Ltd. Also, it is preferably 25 seconds or less, more preferably 20 seconds or less, and even more preferably 18 seconds or less.

[0049] 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 printed surface in which adjacent halftone dots are connected to each other in a halftone dot portion) while maintaining the wettability of the organic solvent-based composition of the present invention to the substrate, and by appropriately decreasing 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.

[0050] When the organic solvent-based composition of the present invention is used for gravure printing or flexographic printing, it can be produced by using an Eiger mill, a sand mill, a bead mill, a gamma mill, an attritor, or the like which is generally used in the production of gravure or flexographic inks.

[0051] When preparing the organic solvent-based composition of the present invention, from the viewpoint of uniformity, at least a part of the acrylic resin, the colorant, and at least a part of the organic solvent may be mixed in advance to prepare a preliminary composition (kneaded base ink).

[0052] Incidentally, resist ink can be mentioned as an example of a composition that is removed from a substrate as in the present invention. However, the resist ink is intended to process the substrate by removing a coating film from the substrate in advance, leaving only a portion of the coating film. The resist ink has a fundamentally different use and purpose from the coating-forming composition of the present invention, which is intended to remove the entire coating film and recycle the substrate. Therefore, the resist ink does not fall under the well-known technology of the present invention.

[0053] The film-forming composition of the present invention can also be used as a primer composition for forming a primer layer.

[0054] <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.

[0055] 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, 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. These may be used singly or in combination. When (meth)acrylic resin and / or styrene-(meth)acrylic resin is contained as a binder resin, the content of <<acrylic resin>> above includes the content of the (meth)acrylic resin and / or styrene-(meth)acrylic resin in this item.

[0056] The solvent may be any organic solvent, and for example, the same organic solvents as those explained in the section "Organic Solvent" of the above "Organic Solvent-Based Composition" can be used.

[0057] Examples of the additives include extender pigments, pigment dispersants, leveling agents, defoamers, waxes, plasticizers, antiblocking agents, infrared absorbing agents, ultraviolet absorbing agents, fragrances, and flame retardants.

[0058] When the primer layer contains the above-mentioned <<acrylic resin>>, the amount of the <<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 is, for example, in the range of 5 to 30 mass % relative to the total mass of the composition for the primer layer.

[0059] Also preferably usable are primers to which resins having acidic groups or low molecular weight compounds have been added. 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 above-mentioned "acrylic resin" that is the main component of the primer, organic solvents, etc.

[0060] 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, 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; radical copolymer resins 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 having an acidic group, 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 (excluding the binder resins). These may be used singly or in combination. When (meth)acrylic resin and / or 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 styrene-(meth)acrylic resin in this item.

[0061] 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, undecanedioic acid, dodecanedioic acid, 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 acids and nitrocarboxylic acids, 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.

[0062] The film-forming composition of the present invention can also be used as a varnish composition for forming a varnish layer.

[0063] <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>>.

[0064] The varnish 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.

[0065] 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, 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. These may be used singly or in combination. When (meth)acrylic resin and / or styrene-(meth)acrylic resin is contained as a binder resin, the content of <<acrylic resin>> above includes the content of the (meth)acrylic resin and / or styrene-(meth)acrylic resin in this item.

[0066] The solvent may be any organic solvent, and for example, the same organic solvents as those explained in the section "Organic Solvent" of the above "Organic Solvent-Based Composition" can be used.

[0067] Examples of the additives include extender pigments, pigment dispersants, leveling agents, defoamers, waxes, plasticizers, antiblocking agents, infrared absorbing agents, ultraviolet absorbing agents, fragrances, and flame retardants.

[0068] When the varnish layer contains the above-mentioned <<acrylic resin>>, the amount of <<acrylic resin>> added can 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 mass % of the varnish layer composition, for example.

[0069] In addition, varnishes to which resins having acidic groups or low molecular weight compounds are 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 varnishes.

[0070] 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, 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; radical copolymer resins 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 having an acidic group, 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 (excluding the binder resins). These may be used singly or in combination. When (meth)acrylic resin and / or 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 styrene-(meth)acrylic resin in this item.

[0071] 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.

[0072] 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, undecanedioic acid, dodecanedioic acid, 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 acids and nitrocarboxylic acids, 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.

[0073] (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 the film-forming composition of the present invention is a printing ink that is once adhered 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.

[0074] The film thickness of the printing ink formed by the gravure printing method or 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.

[0075] (Printed matter and laminates) 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 mode.

[0076] As described above, the mode in which a coating is formed on the surface of the base material A directly or via another layer is as follows. <Surface printing> · Substrate A-Printed layer (white)-Printed layer (color) · Substrate A-Primer layer-Printed layer (white)-Printed layer (color) · Substrate A - Printed layer (white) - Printed layer (color) - Varnish layer · Substrate A-Primer layer-Printed layer (white)-Printed layer (color)-Varnish layer · Substrate 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 - Printing layer (color) ·Substrate A-printing layer (white)

[0077] The printed layer (white), the printed layer (color), the primer layer, and the varnish layer are as described above. The substrate A will be described below.

[0078] <Base material 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 polypropylene, polyethylene, and polypropylene 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 not particularly limited, but it is usually within the range of 1 to 500 μm.

[0079] The printing surface of the substrate A is preferably subjected to a corona discharge treatment, and silica, alumina, etc. may be vapor-deposited thereon.

[0080] 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.

[0081] 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 the inorganic substance or inorganic oxide 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.

[0082] The barrier coat layer can protect the inorganic vapor deposition layer and 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 hydrolysate of a metal alkoxide obtained by polycondensing a mixture of a metal alkoxide and a water-soluble polymer by a sol-gel method in the presence of a sol-gel catalyst and a solvent such as water or an organic solvent, or a hydrolysis polycondensate of a metal alkoxide.

[0083] (Method of removing the coating from substrate A) In the present invention, the coating film of the printed matter is removed from the substrate A by treating it with an alkaline solution, thereby producing a recycled substrate A.

[0084] The removal step includes a step of immersing the printed matter or laminate in an alkaline solution while heating and stirring or ultrasonically vibrating at 20 to 90° C. 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.

[0085] 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, an aqueous solution of potassium hydroxide, an aqueous solution of sodium hydrogen carbonate, an aqueous solution of potassium hydrogen carbonate, an aqueous solution of sodium dihydrogen carbonate, an aqueous solution of potassium dihydrogen carbonate, etc. The aqueous solutions of sodium hydroxide, potassium hydroxide, sodium hydrogen carbonate, potassium hydrogen carbonate, sodium dihydrogen carbonate, potassium dihydrogen carbonate, etc. are preferably aqueous solutions with a concentration of 0.5% by mass to 10% by mass, and more preferably aqueous solutions with a concentration of 1% by mass to 5% by mass.

[0086] 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.

[0087] 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 water-insoluble organic solvents 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 can be used alone or in combination of two or more.

[0088] The alkaline solution may contain a surfactant. Examples of the surfactant include various anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc., and among these, anionic surfactants, nonionic surfactants, and amphoteric surfactants are preferred.

[0089] Examples of the anionic surfactant include alkylbenzenesulfonates, alkylphenylsulfonates, alkylnaphthalenesulfonates, higher fatty acid salts, sulfate salts of higher fatty acid esters, sulfonates of higher fatty acid esters, sulfate salts and sulfonates of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, and polyoxyethylene alkyl ether phosphates. Specific examples of these include dodecylbenzenesulfonates, isopropylnaphthalenesulfonates, monobutylphenylphenol monosulfonates, monobutylbiphenylsulfonates, and dibutylphenylphenol disulfonates.

[0090] 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. Among 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.

[0091] Other surfactants that can be used include silicone 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.

[0092] These surfactants can be used alone or in combination of two or more. When a surfactant is added, the amount of the surfactant added is preferably in the range of 0.001 to 2 mass %, more preferably 0.001 to 1.5 mass %, and even more preferably 0.01 to 1 mass %, based on the total amount of the alkaline solution.

[0093] The target printed matter or laminate is immersed in the alkaline solution, for example, in a treatment tank, in a state in which the alkaline solution is heated or ultrasonically vibrated at 20 to 90° C. The heating method is not particularly limited, and known heating methods using heat rays, infrared rays, microwaves, etc. can be used. In addition, ultrasonic vibration can be, for example, a method in which an ultrasonic vibrator is attached to the treatment tank and ultrasonic vibration is applied to the warm water or alkaline solution.

[0094] The alkaline solution is preferably stirred during immersion. Examples of the stirring method include a method of mechanically stirring the dispersion of the printed matter or laminate contained in the treatment tank with a stirring blade, a method of water flow stirring with a water flow pump, and a method of bubbling with an inert gas such as nitrogen gas, and these may be used in combination to efficiently peel the printed matter or laminate.

[0095] The time for immersing the printed matter or laminate 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 in the printed matter to be completely detached from the substrate, but it is preferable that 60% or more of the coating detaches from 100% by mass of the coating, more preferably 70% or more by mass, even more preferably 80% or more by mass, and particularly preferably 90% or more by mass.

[0096] In the desorption step, the number of times of immersion in the alkaline solution may be one or several times. That is, the immersion may be performed once, and then the process of recovering the separated film substrate may be performed, or the immersion may be performed several times, and then the process of recovering the film substrate may be performed. When the immersion is performed several times in the desorption step, the concentration of the alkaline solution may be changed. In addition, during the desorption step, known processes such as washing with water and drying may be appropriately added.

[0097] 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, since 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, discoloration of the alkaline solution after detachment is prevented, and a film having excellent adhesion to the substrate, excellent abrasion resistance, and good toughness can be formed. EXAMPLES

[0098] The contents and effects of the present invention will be described in more detail below with reference to examples, but the present invention is not limited thereto. Note that "parts" and "%" shown below are all based on mass.

[0099] <Hydroxyl value measurement method> The hydroxyl value was measured in accordance with JIS K 0070-1992.

[0100] <Acid value measurement method> The acid value was measured in accordance with JIS K 0070-1992.

[0101] The components of the binder resins (acrylic resins and binder resins other than acrylic resins), colorants (pigments), organic solvents, and auxiliary agents (waxes) used in the following examples and comparative examples are as follows.

[0102] <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)

[0103] <Pigments> White: Titanium oxide pigment (JR600A (manufactured by Teika Co., Ltd.)) Indigo: Phthalocyanine indigo pigment (FASTOGEN BLUE LA5380 indigo pigment (DIC))

[0104] <Organic solvent> Isopropyl alcohol (IPA) Propyl acetate γ-Butyl lactone

[0105] <Wax> Polyethylene wax: Mitsui Chemicals Excelex 20700

[0106] 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 approximately 15 seconds (25°C) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.) to prepare a film-forming composition.

[0107] The composition of each component in 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.

[0108] The prepared film-forming compositions were subjected to the following evaluations, and the evaluation results are shown in Table 2 below.

[0109] <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. <<Printed material composition>> ·Configuration 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 (Mitsubishi Chemical DXL-270-41S, thickness 40 μm) (OPS)

[0110] The resulting print was applied immediately or after leaving for 24 hours, with 5 cm of cellophane tape (12 mm width, made by Nichiban) affixed to the printed surface, and one end of the cellophane tape was quickly peeled off perpendicular to the printed surface. The remaining percentage of the printed film was visually evaluated based on the area ratio.

[0111] [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 film remained on the film. 1: When applying cellophane tape, the printing film peels off from the film to the cellophane tape.

[0112] <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. <<Printed material composition>> ·Configuration 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 (Mitsubishi Chemical DXL-270-41S, thickness 40 μm) (OPS)

[0113] The obtained prints were rubbed on the printed surface using high-quality paper and rubbed 100 times with a commercially available Gakushin-type rub fastness tester under the condition of a load of 500 g. A rating of 4 or higher is within the practical range.

[0114] [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 becomes discolored. 3: Streaky scratches are observed on the printed surface. 2: Thick streak-like scratches are observed on the printed surface. 1: Surface scratches are observed on the printed surface.

[0115] <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. <<Printed material composition>> ·Configuration 1: Base material A-printing layer 1 Substrate A: Corona-treated polyethylene terephthalate film (Toyobo Co., Ltd., Ester E5100, thickness 12 μm) (PET)

[0116] <<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% by mass aqueous solution of sodium hydroxide, 50°C Condition 2: 1.5% by mass aqueous solution of sodium hydroxide, 85°C

[0117] <<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. A test piece of the printed matter cut to a size of 20 mm x 20 mm was immersed in the solution and stirred with a stirrer. After checking the peeling state after stirring, the printed matter was rubbed with a finger to see if rubbing would cause the coating to peel off. The peelability of the ink coating film under the above conditions was evaluated according to the following evaluation criteria.

[0118] [Evaluation Criteria] 5: Ink film peels off within 5 minutes of stirring. Completely peels off when rubbed. 4: After 15 minutes of stirring, the ink film was removed. It was completely removed when rubbed. 3: No ink peeling observed after 15 minutes of stirring. Complete peeling when rubbed. 2: No ink film detachment observed after 15 minutes of stirring. Partial detachment observed when rubbed. 1: No ink film detachment confirmed after 15 minutes of stirring. No ink film detachment confirmed even after rubbing.

[0119] <Evaluation item 4: Contamination with cleaning fluid> The color difference between the cleaning solution after the peeling test performed under each of the conditions 1 and 2 of the above <Evaluation item 3: Peelability> test and a 1.5 mass% aqueous solution of sodium hydroxide was measured using a spectrophotometer / haze meter COH7700 (manufactured by Nippon Denshoku Industries Co., Ltd.) and evaluated according to the following evaluation criteria.

[0120] [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: ΔE7.0 or higher

[0121] 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 approximately 15 seconds (25°C) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.) to prepare a film-forming composition.

[0122] 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.

[0123] Example 3 A film-forming composition was prepared in the same manner as in Example 1, except that the composition for forming a film 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.

[0124] 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 approximately 15 seconds (25°C) using a Zahn cup #3 (manufactured by Rigo Co., Ltd.) to prepare a film-forming composition.

[0125] 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.

[0126] (Example 5~ 7, Reference Example 8, Example 9 11) A film-forming composition was prepared in the same manner as in Examples 1 and 4, except that the composition for forming a film 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.

[0127] (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 for forming a film 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.

[0128] [Table 1]

[0129] [Table 2]

[0130] As described above, 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 from which the film layer can 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

1. 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.

2. The film-forming composition according to claim 1 , wherein the organic solvent further comprises at least one of n-propyl acetate and isopropyl alcohol.

3. The film-forming composition according to claim 1 , further comprising a colorant.

4. The film-forming composition according to claim 3, which is used as a printing ink.

5. The film-forming composition according to claim 1 , which is used as a primer or a varnish.

6. A printed matter having a coating comprising the coating composition according to any one of claims 1 to 5, directly or via another layer on the surface of a substrate A.

7. 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.

8. The printed matter according to claim 6 , wherein no substrate is disposed on a surface of the coating opposite to a surface on which the substrate A is disposed.

9. A method for producing a recycled substrate A, comprising treating the printed matter according to claim 6 with an alkaline solution to remove the coating from the substrate A.

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