Method for manufacturing printed matter and recycled base material

Abstract

Provided are: a method for producing a recycled board, the method making it possible to suppress coloration of an alkali solution after a coating film is removed from a plastic substrate by a treatment with the alkali solution; and a printed item having a removable coating film, the printed item being suitable for use in the method for producing the recycled board.　The printed item comprises a laminate of a substrate and a coating film which is removable from the substrate by a treatment with an alkali solution, wherein the coating film comprises: a first layer which contains a colorant and at least one resin A selected from the group consisting of acrylic resins, urethane resins, polyamide resins, rosin resins, and polyester resins; and a second layer which is in contact with the first layer. The second layer contains at least one resin B selected from the group consisting of vinyl chloride / vinyl acetate copolymer resins, poly(vinyl butyral) resins, cellulose acetate propionate resins, and cellulose acetate butyrate resins.

Description

Technical Field

[0001] The present invention relates to a printed matter having a film detachable from a base material, and a method for producing a recycled base material for obtaining a recycled base material from the printed matter.

Background Art

[0002] In recent years, the problem of marine plastics has become apparent due to plastics discarded or dumped into the ocean being decomposed in seawater and becoming finer (microplastics). There is concern that this microplastic enters the bodies of marine organisms, accumulates, and affects 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 flexible packaging materials and plastic bottles leads to preventing plastics from entering the ocean. However, in current recycling, the printed layer printed on the plastic base material does not detach in the recycling process, mixes into the plastic, causes deterioration of hue and reduction of physical properties, and there is a problem of reducing the value of recycled plastics. If it is possible to detach the film from the plastic base material in the recycling process and solve this problem, the value of recycled plastics will be improved, leading to the entry of new recycling operators and the improvement of the separate collection system by local governments. Thus, it is considered that the problem of marine plastics will be improved by increasing the recycling rate. Therefore, the development of a method for detaching a film from a plastic base material in the recycling process is required. In addition, since the film-forming materials widely used for plastic base materials are being replaced with toluene-free and methyl ethyl ketone (MEK)-free ones in consideration of the effects on the health of workers and the environment, materials for solving the above problems also need to be developed in consideration of this.

[0003] In the prior art, a method for detaching a film containing a styrene-acrylic resin, a phenol resin, or a styrene-maleic resin printed on a heat-shrinkable PET film as a vehicle with alkaline water has been disclosed (Patent Document 1). Similarly, a method has been disclosed in which a coat layer containing a styrene-maleic resin, a rosin-maleic resin, or an acrylic acid copolymer resin is formed between film layers on a heat-shrinkable PET film, and the coat layer is detached with alkaline water (Patent Documents 2 and 3). However, these techniques only guarantee characteristics for specific heat-shrinkable PET substrates, and there are limitations such as the need to additionally provide a coat layer separate from the film layer, and they are not suitable for recycling general-purpose plastic substrates containing polyolefin. On the other hand, an organic solvent-based printing ink for alkaline water detachment using a urethane resin having an acid value as a binder resin has also been disclosed (Patent Documents 4, 5, and 6). However, when a urethane resin having an acid value is used as the main binder resin, it is assumed that the adhesion to the substrate is not sufficient, and by imparting an acid value to the urethane resin, the viscosity of the resin increases, and it becomes necessary to use a solvent that has a great impact on health and the environment for viscosity adjustment, or to avoid the coexistence of an amine value and an acid value for viscosity reduction. As a result, problems such as a decrease in compatibility for laminating applications also occur, and there are still issues for general use as a material from which the film can be detached. On the other hand, regarding the development of technologies to promote the detachment of the above-mentioned printed films, almost no consideration is given to the release of the detached film into the cleaning liquid. In particular, there is no clear effective solution to the problem that the colored pigment contained in the ink causes release and coloring into the cleaning liquid during cleaning, resulting in an increased environmental burden due to the emergence of wastewater treatment problems.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Patent Document 2

[0005] The problem to be solved by the present invention is to provide a method for manufacturing a recycled substrate capable of suppressing the coloring of an alkaline solution after peeling a film from a plastic substrate by treatment with the alkaline solution, and a printed matter having a peelable film that can be suitably used in the method for manufacturing the recycled substrate. [Means for Solving the Problems]

[0006] As a result of intensive studies to solve the above problems, the inventors have found that, as a film that peels off from a substrate by treatment with an alkaline solution, a structure in which at least two layers of a first layer having a colorant and a second layer in contact with the first layer are laminated, and by containing a specific coloration inhibitor in the second layer, the above problems can be solved, and the present invention has been completed.

[0007] That is, the present invention includes the following aspects. [1] A printed matter comprising a laminate of a substrate and a film peelable from the substrate by treatment with an alkaline solution, wherein the film has a first layer containing a colorant and at least one resin A selected from the group consisting of an acrylic resin, a urethane resin, a polyamide resin, a rosin resin, and a polyester resin, and a second layer in contact with the first layer. The printed matter, wherein the second layer contains at least one resin B selected from the group consisting of vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, cellulose acetate propionate resin, and cellulose acetate butyrate resin. [2] The printed matter according to [1], wherein the first layer further contains a nitrocellulose resin. [3] The printed matter according to [1], wherein the first layer further contains a vinyl chloride-vinyl acetate copolymer resin. [4] The first layer is (i) containing at least a urethane resin and a nitrocellulose resin, (ii) containing at least an acrylic resin and a nitrocellulose resin, (iii) containing at least a polyamide resin and a nitrocellulose resin, and (iv) containing at least an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, and a cellulose acetate butyrate resin, and is any one of the printed matters according to [1]. [5] The printed matter according to [1], wherein the content ratio of the resin B to the total amount of the resins contained in the second layer is 30% by mass or more. [6] The printed matter according to [1], wherein a third layer for promoting detachment is further disposed between the base material and the film. [7] A method for manufacturing a recycled base material, wherein the film is detached from the plastic base material by treatment with an alkaline solution for the printed matter according to [1] to obtain a recycled base material. [8] The method for manufacturing a recycled base material according to [7], wherein the alkaline solution has a pH of 9 or more and contains a nonionic surfactant.

Advantages of the Invention

[0008] According to the present invention, when the film is detached from the plastic base material by treatment with an alkaline solution, a method for manufacturing a recycled substrate capable of suppressing the coloring of the alkaline solution after detachment, and a printed matter having a detachable film that can be suitably used for the method for manufacturing the recycled substrate can be provided.

Best Mode for Carrying Out the Invention

[0009] Hereinafter, the present invention will be described in detail. It should be noted that the description of the constituent elements described below is an exemplification for explaining the present invention, and the present invention is not limited to these contents.

[0010] (Printed matter) The printed matter of the present invention comprises a laminate of a base material and a film that can be detached from the base material by treatment with an alkaline solution. The film has a structure in which two layers, a first layer and a second layer in contact with the first layer, are laminated. The first layer contains a colorant and at least one resin A selected from the group consisting of an acrylic resin, a urethane resin, a polyamide resin, a rosin resin, and a polyester resin. The second layer contains at least one resin B selected from the group consisting of a vinyl chloride-vinyl acetate copolymer resin, a polyvinyl butyral resin, a cellulose acetate propionate resin, and a cellulose acetate butyrate resin.

[0011] <Film> The film according to the present invention has a first layer and a second layer in contact with the first layer. When the film is detached by treatment with an alkaline solution, since the colorant is contained in the first layer, the alkaline solution after detachment is colored. However, in the aspect of the present invention, since the resin B contained in the second layer exhibits a coloring suppression effect, the coloring of the alkaline solution after detachment is significantly suppressed, and a clear alkaline solution can be obtained. Although not all of the action mechanisms that can obtain a remarkable coloring suppression effect on the alkaline solution after detachment have been clarified, an example of the presumed action mechanism will be described.

[0012] Since the alkaline solution for detaching the film is classified as a strong alkali, the resin contained in the film is decomposed by the alkaline solution (particularly, when the film contains a nitrocellulose resin (so-called nitrocellulose), the nitrocellulose resin is decomposed in a short time), the colorant diffuses into the alkaline solution, and the alkaline solution is colored with the color derived from the colorant. On the other hand, the film according to the present invention contains at least one resin B selected from the group consisting of a vinyl chloride-vinyl acetate copolymer resin, a polyvinyl butyral resin, a cellulose acetate propionate resin, and a cellulose acetate butyrate resin. These resin Bs adhere to resins such as nitrocellulose resin and colorants, and it is considered that the coloring of the alkaline solution can be suppressed by effectively protecting the resins and colorants from alkali.

[0013] When the film according to the present invention detaches the film from the substrate by treatment with an alkaline solution, the coloring suppression effect of the alkaline solution after detachment is remarkably exhibited. Therefore, water quality pollution and environmental load due to colored drainage can be prevented. In addition, since raw materials and manufacturing equipment for decoloring treatment of colored drainage are not required, it is possible to reduce the manufacturing cost when recycling the substrate. Furthermore, since no process for decoloring treatment is required and the recycling efficiency of the substrate is excellent, it is very useful industrially.

[0014] <<First layer>> The first layer is formed using a composition for forming the first layer (in this specification, such a composition is also referred to as composition (I)). The composition (I) for forming the first layer contains a colorant. In addition, the composition (I) contains at least one resin A selected from the group consisting of an acrylic resin, a urethane resin, a polyamide resin, a rosin resin, and a polyester resin. The composition (I) may further contain a nitrocellulose resin (nitrocellulose). The composition (I) may further contain a vinyl chloride-vinyl acetate copolymer resin (also referred to as a vinyl chloride-vinyl acetate resin). In addition to the above-described resin A, nitrocellulose resin, and vinyl chloride-vinyl acetate copolymer resin, the composition (I) may contain other resins. Further, the composition (I) may contain an organic solvent, and the composition (I) may also contain other components such as auxiliaries and acidic additives. Hereinafter, the components of the composition (I) will be described.

[0015] <<<Colorant>>> Examples of the components of the colorant include coloring dyes and / or coloring pigments, and among them, coloring pigments (hereinafter, also simply referred to as pigments) are preferable.

[0016] - Pigment― Examples of the pigments used in the present invention include inorganic pigments or organic pigments used in general inks, paints, recording agents, etc. From the viewpoint of effectively exerting the coloring suppression effect of the alkaline solution after desorption, organic pigments are preferable.

[0017] Examples of organic pigments include soluble azo, insoluble azo, azo, phthalocyanine, halogenated phthalocyanine, anthraquinone, ansanthrone, dianthraquinonyl, anthrapyrimidine, perylene, perinone, quinacridone, thioindigo, dioxazine, isoindolinone, quinophthalone, azomethine azo, flavanthrone, diketopyrrolopyrrole, isoindoline, indanthrone, carbon black-based pigments, etc. Further, 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. Also, either non-acid-treated pigments or acid-treated pigments can be used. Specific examples of preferred organic pigments are given below.

[0018] Examples of black pigments include, for example, C.I. Pigment Black 1, C.I. Pigment Black 6, C.I. Pigment Black 7, C.I. Pigment Black 9, C.I. Pigment Black 20, etc.

[0019] Examples of blue pigments include, for example, 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. Pigment Blue 63, C.I. Pigment Blue 64, C.I. Pigment Blue 75, C.I. Pigment Blue 79, C.I. Pigment Blue 80, and the like.

[0020] Examples of green pigments include, for example, 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, C.I. Pigment Green 36, and the like.

[0021] 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. 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 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 216, 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.Examples include 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, etc.

[0022] Examples of the purple pigment include, for example, 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. Pigment Violet 38, C.I. Pigment Violet 42, C.I. Pigment Violet 50, etc.

[0023] 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, 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, etc.

[0024] 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 Orange 55, C.I. Pigment Orange 59, C.I. Pigment Orange 61, C.I. Pigment Orange 64, C.I. Pigment Orange 71, or C.I. Pigment Orange 74, etc.

[0025] Examples of the brown pigment include C.I. Pigment Brown 23, C.I. Pigment Brown 25, or C.I. Pigment Brown 26. Among them, preferred pigments include C.I. Pigment Black 7 as the 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, C.I. Pigment Blue 15:6 as the blue pigments, C.I. Pigment Green 7 as the green pigment, 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, 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 as the red pigments, C.I. Pigment Violet 23, C.I. Pigment Violet 37 as the purple pigments, C.I. Pigment Yellow 83, C.I. Pigment Yellow 14, C.I. Pigment Yellow 180, C.I. Pigment Yellow 139 as the yellow pigments, and C.I. Pigment Orange 38, C.I. Pigment Orange 13, C.I. Pigment Orange 34, C.I. Pigment Orange 64 as the orange pigments. It is preferable to use at least one or two or more selected from these groups.

[0026] Examples of the inorganic pigment include carbon black, titanium oxide, red iron oxide, aluminum, mica, zinc oxide, barium sulfate, calcium carbonate, and silica. Also, a metallic luster pigment (Meta Shine; Nippon Sheet Glass Co., Ltd.) in which a metal or metal oxide is coated on a glass flake or massive flake as a base material can be used. From the viewpoints 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 inks, and mica for pearl ink.

[0027] The total pigment content is not particularly limited. For example, in the composition forming the first layer, from the viewpoint of ensuring the coloring power of the composition, the pigment content is preferably 1 to 60 parts by mass, more preferably 5 to 40 parts by mass, based on 100 parts by mass of the total amount of the composition. The total white pigment content may be 15 to 60 parts by mass, or may be 20 to 40 parts by mass, based on 100 parts by mass of the total amount of the composition. The total content of the colored organic pigment may be 1 to 30 parts by mass, or may be 5 to 25 parts by mass, based on 100 parts by mass of the total amount of the pigment composition. Any combination of these upper and lower limits can be used.

[0028] <<<Resin>>> Composition (I) contains at least one resin A selected from the group consisting of an acrylic resin, a urethane resin, a polyamide resin, a rosin resin, and a polyester resin. Composition (I) may contain a resin other than resin A. For example, it may contain a nitrocellulose resin (nitrocellulose). Also, composition (I) may contain resin B contained in the second layer. In particular, it may contain a vinyl chloride-vinyl acetate copolymer resin (also referred to as a vinyl chloride-vinyl acetate resin). Note that resin B will be described in detail in the following <<Second Layer>> section. Furthermore, composition (I) may contain, in addition to the above-described resins, other resins such as a cellulose-based resin, a ketone resin, a chlorinated polypropylene resin, an ethylene-vinyl acetate copolymer resin, a vinyl acetate resin, an alkyd resin, a polyvinyl chloride resin, a cyclized rubber, a chlorinated rubber, a butyral resin, and a petroleum resin (excluding resin B described later). These can be used in appropriate combinations.

[0029] -Urethane resin- The number average molecular weight of the urethane resin is preferably in the range of 15,000 to 100,000. When the number average molecular weight of the urethane resin is less than 15,000, the blocking resistance, chemical resistance, etc. of the composition forming the first layer tend to be low. When it exceeds 100,000, the viscosity of the composition tends to be high, and a predetermined printing density cannot be obtained.

[0030] It is preferable to use polyester polyol and / or polyether polyol as the reaction raw materials of the urethane resin contained in the composition for forming the first layer.

[0031] The number average molecular weight of the polyester polyol is preferably 3,000 to 7,000. When the number average molecular weight of the polyester polyol is less than 3,000, the film of the urethane resin tends to become hard and the adhesiveness to the polyester film tends to decrease. When the number average molecular weight is greater than 7,000, the film of the urethane resin tends to become fragile and the blocking resistance of the film tends to decrease. On the other hand, the polyester polyol is preferably 1 to 50 parts by mass with respect to 100 parts by mass of the urethane resin. When the polyester polyol is less than 1 part by mass, in addition to the decrease in the solubility of the polyurethane resin in ketone, ester, and alcohol solvents, the adhesiveness particularly on a high-functional barrier film tends to decrease. Also, the redissolvability of the film in the solvent decreases, and the reproducibility of the printed matter tends to decrease. When it exceeds 50 parts by mass, the film tends to become overly soft and the blocking resistance tends to be inferior.

[0032] Note that the number average molecular weight of the polyester polyol indicates the value measured under the following conditions by the gel permeation chromatography (GPC) method. Measuring device: High-speed GPC device ("HLC-8220GPC" manufactured by Tosoh Corporation) Column: The following columns manufactured by Tosoh Corporation were connected in series and used. "TSKgel G5000" (7.8 mm I.D. × 30 cm) × 1 piece "TSKgel G4000" (7.8 mm I.D. × 30 cm) × 1 piece "TSKgel G3000" (7.8 mm I.D. × 30 cm) × 1 piece "TSKgel G2000" (7.8 mm I.D. × 30 cm) × 1 piece Detector: RI (differential refractometer) Column temperature: 40°C Eluent: Tetrahydrofuran (THF) Flow rate: 1.0 mL / min Injection volume: 100 μL (tetrahydrofuran solution with a sample concentration of 0.4 mass%) Standard sample: A calibration curve was created using the following standard polystyrene. (Standard polystyrene) "TSKgel Standard Polystyrene A-500" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene A-1000" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene A-2500" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene A-5000" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-1" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-4" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-10" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-20" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-40" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-80" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-128" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-288" manufactured by Tosoh Corporation "TSKgel Standard Polystyrene F-550" manufactured by Tosoh Corporation

[0033] As the polyester polyol, for example, those obtained by a known esterification reaction between a compound having two or more hydroxyl groups and a polybasic acid can be used.

[0034] The compound having two or more of the above hydroxyl groups is used as a chain extender. For example, glycols such as ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol; branched structure glycols such as 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-propanediol, neopentyl glycol, 2-isopropyl-1,4-butanediol, 2,4-dimethyl-1,5-pentanediol, 2,4-diethyl-1,5-pentanediol, 2-ethyl-1,3-hexanediol, 2-ethyl-1,6-hexanediol, 3,5-heptanediol, 2-methyl-1,8-octanediol; aliphatic polyols such as trimethylolpropane, trimethylolethane, pentaerythritol, sucrose, methylene glycol, glycerin, sorbitol; aromatic polyols such as bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, hydroquinone, etc., and compounds with a number average molecular weight in the range of 50 to 400 can be used. These chain extenders can be used alone or in combination of two or more.

[0035] As the above polybasic acid, for example, succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic anhydride, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, phthalic acid, anhydrides of these acids, etc. can be used. These polybasic acids can be used alone or in combination of two or more.

[0036] Moreover, the polyether polyol preferably has a number average molecular weight of 100 to 4,000. Examples of the polyether polyol include polyether polyols that are polymers or copolymers of ethylene oxide, propylene oxide, tetrahydrofuran, etc. Specifically, well-known and commonly used ones such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol may be used, and among them, polyethylene glycol is preferred. By containing the polyester polyol and / or the polyether polyol within the above range, the adhesion on the base film is significantly improved, and as a result, the blocking resistance becomes excellent.

[0037] When the number average molecular weight of the polyether polyol is less than 100, the film of the urethane resin tends to become hard and the adhesiveness to the polyester film is likely to decrease. When the number average molecular weight is greater than 4,000, the film of the urethane resin tends to become fragile and the blocking resistance of the film is likely to decrease. The number average molecular weight of the polyether polyol can be determined by measuring under the same conditions by the gel permeation chromatography (GPC) method, similar to the above polyester polyol.

[0038] Examples of the diisocyanate compounds used in the urethane resin in the composition for forming the first layer include various known aromatic diisocyanates, aliphatic diisocyanates, alicyclic diisocyanates, etc. generally used in the production of urethane resins. For example, 1,5-naphthylene diisocyanate, 4,4'-diphenylmethane diisocyanate, 4,4'-diphenyldimethylmethane diisocyanate, 4,4'-dibenzyl isocyanate, dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, tolylene diisocyanate, butane-1,4-diisocyanate, hexamethylene diisocyanate, isopropylene diisocyanate, methylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, cyclohexane-1,4-diisocyanate, xylylene diisocyanate, isophorone diisocyanate, dimer diisocyanate, isophorone diisocyanate (3-isocyanatomethyl-3,5,5-trimethylcyclohexyl isocyanate; 5-isocyanato-1-(isocyanatomethyl)-1,3,3-trimethylcyclohexane), dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate, 4,4-diphenylmethane diisocyanate, tolylene diisocyanate, bis-chloromethyl-diphenylmethane-diisocyanate, 2,6-diisocyanate-benzyl chloride, and dimer diisocyanate obtained by converting the carboxyl group of dimer acid into an isocyanate group. These diisocyanate compounds can be used alone or in admixture of two or more.

[0039] As the chain extender used in the urethane resin in the composition for forming the first layer, in addition to ethylenediamine, propylenediamine, hexamethylenediamine, diethylenetriamine, triethylenetetramine, isophoronediamine, dicyclohexylmethane-4,4'-diamine, etc., amines having a hydroxyl group in the molecule such as 2-hydroxyethyl ethylenediamine, 2-hydroxyethylpropylenediamine, 2-hydroxyethylpropylenediamine, di-2-hydroxyethyl ethylenediamine, di-2-hydroxyethylenediamine, di-2-hydroxyethylpropylenediamine, 2-hydroxypyrropylethylenediamine, di-2-hydroxypyrropylethylenediamine, di-2-hydroxypropyl ethylenediamine can also be used. These chain extenders can be used alone or in combination of two or more.

[0040] Furthermore, the amine value of the urethane resin used in the composition for forming the first layer is preferably 10.0 mgKOH / g or less. When the amine value exceeds 10.0 mgKOH / g, the blocking resistance tends to be poor, and in addition, the two-component stability after adding the curing agent decreases. From the viewpoint of maintaining good blocking resistance and two-component stability while maintaining plate fogging property, adhesiveness, and extrusion lamination strength, the range of 1.0 to 5.0 mgKOH / g is more preferable, and more preferably the range of 1.0 to 3.5 mgKOH / g.

[0041] -Acrylic resin- The acrylic resin is obtained by copolymerizing various (meth)acrylate monomers and, if necessary, other polymerizable unsaturated group-containing compounds.

[0042] The monomers constituting the acrylic resin are not particularly limited. For example, methyl (meth)acrylate, ethyl (meth)acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, hexyl (meth)acrylate, cyclohexyl (meth)acrylate, octyl (meth)acrylate, nonyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, isobornyl (meth)acrylate, dicyclopentanyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, 2,2,2-trifluoroethyl (meth)acrylate, 2,2,3,3-pentafluoropropyl (meth)acrylate, perfluorocyclohexyl (meth)acrylate, glycidyl (meth)acrylate, allyl glycidyl ether, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, polyethylene glycol mono(meth)acrylate, 2-dimethylaminoethyl (meth)acrylate, (meth)acrylamide, N-monoalkyl (meth)acrylamide, N,N-dialkyl (meth)acrylamide, N-methylol (meth)acrylamide, N-isopropoxymethyl (meth)acrylamide, N-butoxymethyl (meth)acrylamide, N-isobutoxymethyl (meth)acrylamide, 2-aziridinylethyl (meth)acrylate, dicyclopentenyl (meth)acrylate, acrolein, diacetone (meth)acrylamide, acetoacetoxyethyl (meth)acrylate and other (meth)acrylic monomers can be used. Note that the above "(meth)acrylate" refers to either one or both of acrylate and methacrylate, and "(meth)acrylic" refers to either one or both of acrylic and methacrylic.

[0043] As the compound containing a polymerizable unsaturated group, in addition to the above (meth)acrylic monomer, vinyl monomers such as vinyl acetate, vinyl propionate, vinyl versatate, methyl vinyl ether, ethyl vinyl ether, propyl vinyl ether, butyl vinyl ether, (meth)acrylonitrile, styrene, α-methylstyrene, divinylstyrene, isoprene, chloroprene, butadiene, ethylene, tetrafluoroethylene, vinylidene fluoride, N-vinylpyrrolidone, etc. can also be used. These may be used alone respectively, or two or more of them may be used in combination.

[0044] The number average molecular weight of the acrylic resin is not particularly limited, but is preferably 3,000 to 50,000, and more preferably 10,000 to 30,000.

[0045] - Polyamide resin - The polyamide resin is obtained by reacting a polycarboxylic acid compound with a polyamine or a polyisocyanate compound. Examples of the polycarboxylic acid compound include succinic acid, maleic acid, fumaric acid, itaconic acid, azelaic acid, mesaconic acid, citraconic acid, sebacic acid, glutaconic acid, adipic acid, malonic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, nadic acid, methyl nadic acid, octyl succinic acid, and anhydrides of these acids, polymerized fatty acids such as dimers and trimers of linolenic acid, dodecanedioic acid, C21 dibasic acid, dimer acid (polymerized fatty acid obtained by polymerizing unsaturated fatty acids such as oleic acid and linoleic acid), etc.

[0046] Furthermore, aliphatic polycarboxylic acids having 7 to 20 carbon atoms such as 1,2,4-butanetricarboxylic acid and 1,2,5-hexanetricarboxylic acid, alicyclic polycarboxylic acids having 9 to 20 carbon atoms such as 1,2,4-cyclohexanetricarboxylic acid, aromatic polycarboxylic acids having 9 to 20 carbon atoms such as 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, and pyromellitic acid, and polycarboxylic acids having a valence of 3 or more such as anhydrides and lower alkyl (methyl, butyl, etc.) esters of these can also be used.

[0047] Examples of polyamines used to obtain polyamide resins include diamines such as ethylenediamine, propylenediamine, diaminobutane, diaminopentane, diaminohexane, diaminoheptane, diaminooctane, diaminodecane, and diaminododecane; and amines with a valence of 3 or higher such as diethylenetriamine and triethylenetetramine.

[0048] The number average molecular weight of the polyamide resin is not particularly limited, but is preferably from 5,000 to 20,000, more preferably from 500 to 10,000.

[0049] -Rosin resin- The rosin-based resin only needs to have a structure derived from rosin in an amount of 20% by mass or more, and preferably has a softening point (ring and ball method) of 30°C to 180°C, more preferably 50 to 170°C. Preferred examples of the rosin-based resin include polymerized rosin resins, rosin-modified maleic acid resins, and rosin-modified fumaric acid resins. The acid value of the rosin-based resin is preferably 50 or more and 350 or less (mgKOH / g). Preferred examples of the rosin-based resin include Aradime R-95 and Markid No. 32 manufactured by Arakawa Chemical Industries, Ltd.

[0050] The weight average molecular weight of the rosin-modified maleic acid resin and the rosin-modified fumaric acid resin is preferably 500 or more, more preferably 700 or more, and even more preferably 1,000 or more. By setting it within the above range, the balance between the adhesion to the substrate and the peelability in an alkaline solution can be achieved.

[0051] Also, the weight average molecular weight of the rosin-modified maleic acid resin and the rosin-modified fumaric acid resin is preferably 50,000 or less, more preferably 30,000 or less, even more preferably 10,000 or less, even more preferably 5,000 or less, and even more preferably 2,000 or less. By setting it within the above range, the viscosity of the ink can be reduced, and the balance between the adhesion to the substrate and the peelability in an alkaline solution can be achieved.

[0052] The weight average molecular weight of the rosin-modified maleic acid resin and the rosin-modified fumaric acid resin is preferably 500 to 50,000, more preferably 700 to 520,000, still more preferably 1,000 to 10,000, and even more preferably 1,000 to 5,000. By setting it within the above range, the printability can be improved.

[0053] - Polyester resin - As the polyester resin, various known polyester resins can be used. The polyester resin can be obtained by reacting a glycol and a dibasic acid or its derivative as essential components. Of course, instead of the above dibasic acid, ester-forming derivatives such as dibasic acid anhydrides and lower alkyl esters of dibasic acids can be used to obtain the polyester resin not only by polycondensation reaction but also by addition reaction or transesterification reaction. Examples of such polyester resins include aliphatic polyester polyols obtained by reacting an aliphatic glycol such as ethylene glycol, propylene glycol, butanediol, pentanediol, hexanediol, heptanediol, decanediol, cyclohexanedimethanol, etc. and an aliphatic dibasic acid such as succinic acid, adipic acid, sebacic acid, suberic acid, azelaic acid, 1,10-decamethylenedicarboxylic acid, cyclohexanedicarboxylic acid, etc. as essential raw material components, and aromatic polyester polyols obtained by reacting an aliphatic glycol such as ethylene glycol, propylene glycol, butanediol, etc. and an aromatic dibasic acid such as terephthalic acid, isophthalic acid, naphthalenedicarboxylic acid, etc. as essential raw material components. Examples of such polyester resins include the "Polyrite" series manufactured by DIC Corporation and the "Kuraray Polyol" series manufactured by Kuraray Co., Ltd.

[0054] - Nitrocellulose resin (nitrocellulose) - By containing the nitrocellulose resin, a film that can be more easily detached from the substrate by treatment with an alkaline solution can be formed more easily. As the nitrocellulose resin contained in the composition for forming the first layer according to the present invention, a general cellulose nitrate ester obtained by treating cellulose with a mixed acid of nitric acid and sulfuric acid can be used. Further, in order to adjust the viscosity of the composition, two or more kinds such as different viscosity standard products according to JIS K-6703 (nitrocellulose for industrial use) (for example, products equivalent to H20 and products equivalent to L1 / 4) may be mixed and used.

[0055] From the viewpoint of contributing to the promotion of film peeling, the content of the nitrocellulose resin is preferably 1 part by mass or more, more preferably 5 parts by mass or more, and still more preferably 8 parts by mass or more with respect to 100 parts by mass of the total amount of the composition (I) for forming the first layer. Further, from the viewpoints of the film-forming property of the ink film and the ink viscosity, the content is preferably 30 parts by mass or less, more preferably 25 parts by mass or less, and still more preferably 20 parts by mass or less.

[0056] - Vinyl chloride-vinyl acetate copolymer resin (vinyl chloride-vinyl acetate resin)- The composition may contain a resin B such as a vinyl chloride-vinyl acetate copolymer resin. The resin B will be described in detail in the following <<Second Layer>> section. By the way, when trying to incorporate the resin B into the first layer, depending on the content of the resin B, compatibility becomes a problem with other resins contained in the first layer. Therefore, in the present invention, a resin B that exhibits an effect of suppressing the coloring of the alkaline treatment solution is contained in a layer different from the first layer (so-called second layer), ensuring the degree of freedom in selecting the types and contents of the components of the first layer. However, as long as compatibility with other resins contained in the first layer does not become a problem, the use of the resin B in the first layer is not excluded, and as long as the degree of freedom in selecting the types and contents of the components of the first layer is not hindered, the resin B may be contained in the first layer.

[0057] The content of the resin B is preferably 0.1 part by mass or more, more preferably 0.05 part by mass or more, still more preferably 0.1 part by mass or more, and particularly preferably 0.3 part by mass or more with respect to 100 parts by mass of the total amount of the composition (I) for forming the first layer. Further, the content is preferably 10 parts by mass or less, and more preferably 6 parts by mass or less.

[0058] <<<Preferred combination of resins contained in the composition (I) for forming the first layer>>> The composition (I) for forming the first layer is preferably in a form containing at least two or more resins as shown in the following (i) to (iii). (i) Containing at least a urethane resin and a nitrocellulose resin (ii) Containing at least an acrylic resin and a nitrocellulose resin (iii) Containing at least a polyamide resin and a nitrocellulose resin In the present invention, a resin B that exhibits an effect of suppressing the coloring of the alkali treatment solution is contained in a layer different from the first layer (so-called second layer). However, as described above, as long as the compatibility with other resins contained in the first layer does not pose a problem, resin B may be contained in the first layer. Therefore, the composition (I) for forming the first layer is also preferably in a form containing at least two or more resins as shown in the following (iv). (iv) Containing at least an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, and a cellulose acetate butyrate resin

[0059] <<<Content of resin in the composition (I) for forming the first layer>>> The content of the resin in the composition (I) is not particularly limited, but is preferably 20 parts by mass or more, more preferably 30 parts by mass or more, and even more preferably 40 parts by mass or more with respect to 100 parts by mass of the total amount of the composition. Also, the total content is preferably 60 parts by mass or less, and more preferably 55 parts by mass or less. When two or more resins are contained in the composition (I), the preferred range of the above content is the total amount of the resins to be contained.

[0060] <<<Organic solvent>>> The composition (I) may contain an organic solvent. The organic solvent is not particularly limited, and examples thereof include aromatic hydrocarbon-based organic solvents such as toluene, xylene, Solvesso #100, and Solvesso #150; aliphatic hydrocarbon-based organic solvents such as hexane, methylcyclohexane, heptane, octane, and decane; and various ester-based organic solvents such as methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, butyl acetate, amyl acetate, ethyl formate, and butyl propionate. Further, as water-miscible organic solvents, there are alcohol-based solvents such as methanol, ethanol, propanol, butanol, isopropyl alcohol, and normal propyl alcohol; ketone-based solvents such as acetone, methyl ethyl ketone, and cyclohexanone; and various glycol ether-based organic solvents 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. Among these, various ester-based organic solvents and various alcohol-based organic solvents are preferred, and isopropyl alcohol and ethyl acetate are more preferred. These can be used alone or in combination of two or more.

[0061] The content of the organic solvent is not particularly limited, but is preferably 20% by mass or more, more preferably 30% by mass or more, based on 100 parts by mass of the total amount of the composition (I). Also, it is preferably 70% by mass or less, more preferably 65% by mass or less, still more preferably 60% by mass or less, and most preferably 55% by mass or less.

[0062] <<<Other components>>> The composition (I) may further contain other components such as auxiliary agents and acidic additives, if necessary.

[0063] As auxiliaries, waxes such as paraffin wax, polyethylene wax, and carnauba wax for imparting abrasion resistance, slipperiness, etc.; fatty acid amide compounds such as oleic acid amide, stearic acid amide, and erucic acid amide; silicone-based and non-silicone-based defoaming agents for suppressing foaming during printing; dispersants, etc. can be appropriately used. As the dispersant, a nonionic dispersant is preferred.

[0064] 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. Further, for example, it may be 1 mgKOH / g or more, and further 3 mgKOH / g or more.

[0065] 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, 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 with respect to 100 parts by mass of the above coloring agent (for example, pigment).

[0066] As the acidic additive, for example, an organic acid or a resin having an acidic group can be used. The acid value of the above acidic additive is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, still more preferably 5 mgKOH / g or more, even more preferably 10 mgKOH / g or more, still more preferably 20 mgKOH / g or more, even more preferably 30 mgKOH / g or more, still more preferably 40 mgKOH / g or more, and most preferably 50 mgKOH / g or more. Also, the acid value is preferably 900 mgKOH / g or less, more preferably 850 mgKOH / g or less, still more preferably 800 mgKOH / g or less, even more preferably 750 mgKOH / g or less, still more preferably 700 mgKOH / g or less, even more preferably 650 mgKOH / g or less, still more preferably 600 mgKOH / g or less, and most preferably 550 mgKOH / g or less. By setting the range as above, it is possible to achieve both the desorbability in the alkaline solution and the adhesion to the substrate.

[0067] When emphasizing the desorbability in the alkaline solution, 50 mgKOH / g or more is preferable, 100 mgKOH / g or more is more preferable, 200 mgKOH / g or more is more preferable, 300 mgKOH / g or more is more preferable, 400 mgKOH / g or more is more preferable, 500 mgKOH / g or more is more preferable, and 550 mgKOH / g or more is particularly preferable. When emphasizing the adhesion to the substrate, 550 mgKOH / g or less is preferable, 500 mgKOH / g or less is more preferable, 400 mgKOH / g or less is more preferable, 300 mgKOH / g or less is more preferable, and 200 mgKOH / g or less is more preferable.

[0068] When emphasizing both the desorbability in the alkaline solution and the adhesion to the substrate, the acid value range is preferably 1 to 900 mgKOH / g, more preferably 3 to 850 mgKOH / g, still more preferably 5 to 800 mgKOH / g, even more preferably 10 to 750 mgKOH / g, still more preferably 20 to 700 mgKOH / g, even more preferably 30 to 650 mgKOH / g, still more preferably 40 to 600 mgKOH / g, and most preferably 50 to 550 mgKOH / g.

[0069] When emphasizing the detachability in an alkaline solution, 50 to 900 mgKOH / g is preferable, 65 to 900 mgKOH / g is preferable, 80 to 900 mgKOH / g is preferable, 100 to 900 mgKOH / g is more preferable, 200 to 900 mgKOH / g is more preferable, 300 to 900 mgKOH / g is more preferable, 400 to 900 mgKOH / g is more preferable, 500 to 900 mgKOH / g is more preferable, 550 to 900 mgKOH / g is more preferable. When emphasizing the adhesion to the substrate, 1 to 550 mgKOH / g is preferable, 1 to 500 mgKOH / g is more preferable, 1 to 400 mgKOH / g is more preferable, 1 to 300 mgKOH / g is more preferable, 1 to 200 mgKOH / g is more preferable.

[0070] When the molecular weight of the acidic additive balances the detachability in the alkaline solution and the adhesion to the substrate, 50 or more is preferable, 60 or more is preferable, 80 or more is preferable, 100 or more is preferable, 150 or more is preferable, 200 or more is preferable, 250 or more is preferable, 300 or more is preferable. Also, 2000 or less is preferable, 1800 or less is preferable, 1500 or less is preferable, 1200 or less is preferable, 1000 or less is preferable. As the range of the molecular weight, 50 to 2000 is preferable, 50 to 1800 is preferable, 50 to 1500 is preferable, 60 to 1500 is preferable, 80 to 1500 is preferable, 100 to 1500 is preferable, 150 to 1500 is preferable, 200 to 1500 is preferable, 250 to 1500 is preferable, 300 to 1500 is preferable, 300 to 1200 is preferable, 300 to 1000 is preferable.

[0071] The above organic acid refers to a low-molecular organic compound having an acidic group. As the low-molecular compound having an acidic group, saturated fatty acids, unsaturated fatty acids, hydroxy acids, aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids, oxocarboxylic acids, carboxylic acid derivatives, etc. are preferably exemplified, and these can be used singly or in a mixture of plural.

[0072] Examples of saturated fatty acids include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, capric acid, undecanoic acid, dodecanoic acid, etc. Examples of unsaturated fatty acids include oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, sorbic acid, etc. Examples of hydroxy acids include lactic acid, malic acid, citric acid, etc. Examples of aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, cinnamic acid, etc. Examples of dicarboxylic acids 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 tricarboxylic acids include aconitic acid, trimer acid, etc. Examples of oxocarboxylic acids include pyruvic acid, oxaloacetic acid, etc. Examples of carboxylic acid derivatives include amino acids, nitrocarboxylic acids. These can be used alone or in a mixture of two or more. Also, if it is 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., it can comply with the so-called Swiss Ordinance, and it is preferable to use substances that comply with various regulations.

[0073] The acid value of the above organic acid is preferably 1 mg KOH / g or more, more preferably 3 mg KOH / g or more, still more preferably 5 mg KOH / g or more, still more preferably 10 mg KOH / g or more, still more preferably 20 mg KOH / g or more, still more preferably 30 mg KOH / g or more, still more preferably 40 mg KOH / g or more, still more preferably 50 mg KOH / g or more, still more preferably 60 mg KOH / g or more, still more preferably 70 mg KOH / g or more, still more preferably 80 mg KOH / g or more, still more preferably 90 mg KOH / g or more, and particularly preferably 100 mg KOH / g or more. Also, the acid value is preferably 900 mg KOH / g or less, more preferably 850 mg KOH / g or less, still more preferably 800 mg KOH / g or less, still more preferably 750 mg KOH / g or less, still more preferably 700 mg KOH / g or less, still more preferably 650 mg KOH / g or less, still more preferably 600 mg KOH / g or less, and more preferably 550 mg KOH / g or less. By setting it within the above range, it is possible to achieve both the desorbability in an alkaline solution and the adhesion to the substrate.

[0074] When emphasizing the desorbability in an alkaline solution, 100 mg KOH / g or more is preferable, 150 mg KOH / g or more is more preferable, 200 mg KOH / g or more is more preferable, 250 mg KOH / g or more is more preferable, 300 mg KOH / g or more is more preferable, 350 mg KOH / g or more is more preferable, 400 mg KOH / g or more is more preferable, 450 mg KOH / g or more is more preferable, 500 mg KOH / g or more is more preferable, and 550 mg KOH / g or more is more preferable. When emphasizing the adhesion to the substrate, 550 mg KOH / g or less is preferable, 500 mg KOH / g or less is more preferable, 400 mg KOH / g or less is more preferable, 300 mg KOH / g or less is more preferable, and 200 mg KOH / g or less is more preferable.

[0075] When both the alkali solution detachability and the adhesion to the substrate are emphasized, the acid value preferably ranges from 1 to 900 mgKOH / g, more preferably from 3 to 850 mgKOH / g, still more preferably from 10 to 800 mgKOH / g, yet more preferably from 20 to 750 mgKOH / g, still more preferably from 30 to 700 mgKOH / g, yet more preferably from 50 to 650 mgKOH / g, still more preferably from 80 to 600 mgKOH / g, and most preferably from 100 to 550 mgKOH / g. When the detachability in the alkali solution is emphasized, it preferably ranges from 100 to 900 mgKOH / g, more preferably from 150 to 900 mgKOH / g, still more preferably from 200 to 900 mgKOH / g, yet more preferably from 250 to 900 mgKOH / g, still more preferably from 300 to 900 mgKOH / g, yet more preferably from 350 to 900 mgKOH / g, still more preferably from 400 to 900 mgKOH / g, yet more preferably from 450 to 900 mgKOH / g, still more preferably from 500 to 900 mgKOH / g, and most preferably from 550 to 900 mgKOH / g. When the adhesion to the substrate is emphasized, it preferably ranges from 1 to 550 mgKOH / g, more preferably from 1 to 500 mgKOH / g, still more preferably from 1 to 400 mgKOH / g, yet more preferably from 1 to 300 mgKOH / g, and most preferably from 1 to 200 mgKOH / g.

[0076] The number of carbon atoms of the above organic acid is preferably 3 or more, more preferably 4 or more, still more preferably 5 or more, yet more preferably 6 or more, still more preferably 7 or more, and most preferably 8 or more. By setting the number of carbon atoms of the above organic acid within the above range, the adhesion to the substrate can be enhanced. Also, the number of carbon atoms of the above organic acid is preferably 20 or less, more preferably 18 or less, and still more preferably 16 or less. By setting the number of carbon atoms of the above organic acid within the above range, the dispersibility in the aqueous medium can be enhanced. The range of the number of carbon atoms of the above organic acid is preferably from 3 to 20, more preferably from 3 to 18, still more preferably from 4 to 18, yet more preferably from 5 to 18, still more preferably from 6 to 18, yet more preferably from 6 to 16, still more preferably from 7 to 16, and most preferably from 8 to 16.

[0077] When attaching importance to the detachability from the substrate and the water resistance of the film, the solubility of the above-mentioned organic acid in 100 g of water at 25°C is preferably less than 2 g, more preferably less than 1.8 g, still more preferably less than 1.5 g, and particularly preferably less than 1.2 g.

[0078] Examples of the resin having the acidic group include resins having an acid value such as cellulose resins, ketone resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, alkyd resins, polyvinyl chloride resins, cyclized rubbers, chlorinated rubbers, butyral resins, petroleum resins, etc., polymerizable monomers having a carboxyl group such as itaconic acid, maleic acid, fumaric acid, cinnamic acid or their acid anhydrides, polymerizable monomers having a sulfonic acid group such as sulfonated styrene, polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide, etc. Resins which are radical copolymers such as styrene-(meth)acrylic resins, styrene-(anhydrous)maleic acid resins, terpene-(anhydrous)maleic acid resins, etc., obtained by copolymerizing polymerizable monomers having an acidic group, and acid-modified polyolefin resins (excluding the above-mentioned coloring inhibitors and resins) etc. may be mentioned, and these can be used singly or in combination of two or more. As the resin having the acidic group, styrene-(anhydrous)maleic acid resins etc. are more preferable.

[0079] The acid value of the resin having the acidic group is preferably 1 mgKOH / g or more, more preferably 3 mgKOH / g or more, still more preferably 5 mgKOH / g or more, still more preferably 10 mgKOH / g or more, still more preferably 20 mgKOH / g or more, still more preferably 30 mgKOH / g or more, still more preferably 40 mgKOH / g or more, and particularly preferably 50 mgKOH / g or more. Also, the acid value is preferably 300 mgKOH / g or less, more preferably 280 mgKOH / g or less, still more preferably 260 mgKOH / g or less, still more preferably 240 mgKOH / g or less, still more preferably 220 mgKOH / g or less, and still more preferably 200 mgKOH / g or less. By setting it within the above range, it is possible to achieve both the detachability with an alkaline solution and the adhesion to the substrate.

[0080] When emphasizing the detachability in an alkaline solution, it is preferably 50 mgKOH / g or more, more preferably 60 mgKOH / g or more, still more preferably 70 mgKOH / g or more, yet more preferably 80 mgKOH / g or more, even more preferably 90 mgKOH / g or more, and particularly preferably 100 mgKOH / g or more. When emphasizing the adhesion to the substrate, it is preferably 200 mgKOH / g or less, more preferably 180 mgKOH / g or less, still more preferably 160 mgKOH / g or less, yet more preferably 140 mgKOH / g or less, even more preferably 120 mgKOH / g or less, and more preferably 100 mgKOH / g or less. When emphasizing both the detachability in an alkaline solution and the adhesion to the substrate, the acid value range is preferably 1 to 300 mgKOH / g, preferably 3 to 300 mgKOH / g, preferably 5 to 280 mgKOH / g, more preferably 10 to 260 mgKOH / g, still more preferably 20 to 240 mgKOH / g, yet more preferably 30 to 220 mgKOH / g, even more preferably 40 to 200 mgKOH / g, and more preferably 50 to 200 mgKOH / g.

[0081] When emphasizing the detachability in an alkaline solution, it is preferably 50 to 300 mgKOH / g, more preferably 60 to 300 mgKOH / g, still more preferably 70 to 300 mgKOH / g, yet more preferably 80 to 300 mgKOH / g, even more preferably 90 to 300 mgKOH / g, and more preferably 100 to 300 mgKOH / g. When emphasizing the adhesion to the substrate, it is preferably 1 to 200 mgKOH / g, more preferably 1 to 180 mgKOH / g, still more preferably 1 to 160 mgKOH / g, yet more preferably 1 to 140 mgKOH / g, even more preferably 1 to 120 mgKOH / g, and more preferably 1 to 100 mgKOH / g.

[0082] When the weight average molecular weight of the resin having the above acidic group is such that when the resin having the above acidic group is a styrene-(anhydrous) maleic acid resin, it is preferably 500 or more, more preferably 700 or more, and still more preferably 1000 or more. By setting the weight average molecular weight of the resin having the above acidic group within the above range, it is possible to balance the adhesion to the substrate and the detachability in an alkaline solution.

[0083] In addition, when the resin having the acidic group is a styrene-(anhydrous) maleic acid resin, the weight average molecular weight of the resin having the acidic group is preferably 100,000 or less, more preferably 70,000 or less, still more preferably 50,000 or less, and even more preferably 30,000 or less. By setting the weight average molecular weight of the resin having the acidic group within the above range, the composition (I) can be made to have a lower viscosity, and furthermore, the balance between the adhesion to the substrate and the peelability in an alkaline solution can be achieved.

[0084] When the resin having the acidic group is a styrene-(anhydrous) maleic acid resin, the weight average molecular weight of the resin having the acidic group is preferably in the range of 500 to 100,000, more preferably 700 to 30,000, still more preferably 1,000 to 50,000, and even more preferably 1,000 to 30,000. By setting the weight average molecular weight of the resin having the acidic group within the above range, the printability can be enhanced.

[0085] From the viewpoints of the redissolubility of the composition (I), the suppression of blocking of the printed matter, the improvement of the printing density, and the adhesion to the substrate, the content of the acidic additive as a solid content is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, still more preferably 1 part by mass or more, even more preferably 1.5 part by mass or more, and still even more preferably 2 part by mass or more, and preferably 60 parts by mass or less, more preferably 55 parts by mass or less, still more preferably 50 parts by mass or less, based on 100 parts by mass of the total amount of the composition (I). The content range of the acidic additive as a solid content is preferably 0.1 to 60 parts by mass, more preferably 0.5 to 55 parts by mass, still more preferably 1 to 50 parts by mass, even more preferably 1.5 to 45 parts by mass, and still even more preferably 2 to 40 parts by mass.

[0086] When the acidic additive is an organic acid, the content of the organic acid as a solid content is preferably 0.1 part by mass or more, more preferably 0.2 part by mass or more, more preferably 0.3 part by mass or more, more preferably 0.5 part by mass or more, more preferably 1 part by mass or more, more preferably 1.5 part by mass or more, more preferably 2 part by mass or more, preferably 20 parts by mass or less, more preferably 18 parts by mass or less, more preferably 16 parts by mass or less, more preferably 14 parts by mass or less, more preferably 12 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the total amount of the composition (I). The range of the content of the organic acid as a solid content is preferably 0.1 to 20 parts by mass, more preferably 0.2 to 18 parts by mass, more preferably 0.3 to 16 parts by mass, more preferably 0.5 to 14 parts by mass, more preferably 1 to 12 parts by mass, more preferably 1.5 to 10 parts by mass, more preferably 2 to 10 parts by mass.

[0087] When the acidic additive is a resin having an acidic group, the content of the resin having an acidic group as a solid content is preferably 0.1 part by mass or more, more preferably 0.5 part by mass or more, more preferably 1 part by mass or more, more preferably 1.5 part by mass or more, more preferably 2 part by mass or more, preferably 60 parts by mass or less, more preferably 55 parts by mass or less, more preferably 50 parts by mass or less, based on 100 parts by mass of the total amount of the composition (I). The range of the content of the acidic additive as a solid content is preferably 0.1 to 60 parts by mass, more preferably 0.5 to 55 parts by mass, more preferably 1 to 50 parts by mass, more preferably 1.5 to 45 parts by mass, more preferably 2 to 40 parts by mass.

[0088] In addition to the above, water, wetting agent, adhesion aid, leveling agent, antistatic agent, viscosity modifier, metal chelate, trapping agent, blocking inhibitor, isocyanate-based curing agent, silane coupling agent can also be used as required.

[0089] The viscosity of Composition (I) 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 #4 manufactured by the dissociating company. Also, it is preferably 25 seconds or less, more preferably 20 seconds or less, and even more preferably 18 seconds or less.

[0090] The surface tension of Composition (I) 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 moderately increasing the surface tension of Composition (I), it is possible to suppress dot bridging (stains on the printed surface where adjacent dots are connected at the halftone dot portions) while maintaining the wettability of Composition (I) on the substrate. By moderately lowering the surface tension of Composition (I), it is possible to enhance the wettability of Composition (I) on the substrate and suppress repellency.

[0091] <<Second Layer>> The second layer is formed using a composition for forming the second layer (in this specification, such a composition is also referred to as Composition (II)). The composition (II) for forming the second layer contains at least one resin B selected from the group consisting of vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, cellulose acetate propionate resin, and cellulose acetate butyrate resin. In the second layer, the content ratio of resin B to the total amount of resin contained in the second layer, that is, the content ratio of resin B to the total amount of resin contained in composition (II), is preferably 30% by mass or more. Composition (II) can also contain resins other than resin B described above. For example, it may contain resin A described in the <<First Layer>> section above and other resins. Also, composition (II) may contain various additives as other components. Hereinafter, the components of composition (II) will be described.

[0092] <<<Resin B>>> Resin B adheres to the resin contained in the film (especially the first layer) (particularly, when the nitrocellulose resin is included in the film, the nitrocellulose resin), or the colorant (e.g., pigment), and can suppress the coloring of the alkaline solution by protecting the resin and the colorant from alkali, etc.

[0093] By including resin B, which exhibits a coloring suppression effect, not in the first layer containing a colorant and having a peeling function, but in the second layer, which is another layer adjacent to the first layer, there is no need to worry about the compatibility between resin B and the resin and colorant contained in the first layer, and the degree of freedom in selecting the type and content of the components of the first layer can be increased.

[0094] Resin B, which exhibits a coloring suppression effect, is at least one resin selected from the group consisting of vinyl chloride-vinyl acetate copolymer resin, polyvinyl butyral resin, cellulose acetate propionate resin, and cellulose acetate butyrate resin. These resins may be used alone or in combination of two or more.

[0095] Among them, from the viewpoint of excellent coloring suppression effect, vinyl chloride-vinyl acetate copolymer resin and polyvinyl butyral resin are preferable, and from the viewpoint of more excellent viscosity stability, polyvinyl butyral resin is preferable.

[0096] -Vinyl chloride-vinyl acetate copolymer resin- Vinyl chloride-vinyl acetate copolymer resin (hereinafter sometimes referred to as vinyl chloride-vinyl acetate resin) is a polymer mainly composed of a structural unit derived from vinyl chloride monomer and a structural unit derived from vinyl acetate monomer. As long as the effects of the present invention are not inhibited, the vinyl chloride-vinyl acetate resin can contain one or more other structural units in addition to vinyl chloride and vinyl acetate.

[0097] The molecular weight of the vinyl chloride-vinyl acetate resin is not particularly limited, but those having a weight average molecular weight of 5,000 to 100,000 are preferable, and 20,000 to 80,000 are more preferable.

[0098] In 100 parts by mass of the total amount of the vinyl chloride-vinyl acetate resin, since a composition having an excellent coloring suppression effect tends to be obtained, the structure derived from the vinyl acetate monomer is preferably 1 to 30 parts by mass, and the structure derived from the vinyl chloride monomer is preferably 70 to 95 parts by mass.

[0099] The glass transition temperature of the vinyl chloride-vinyl acetate resin is not particularly limited, but is preferably 50°C to 90°C.

[0100] -Polyvinyl butyral resin- The polyvinyl butyral resin is a resin obtained by reacting polyvinyl alcohol with butyraldehyde to butyralize the hydroxyl groups of the polyvinyl alcohol resin, and has a structure having a butyral group, an acetyl group, and a hydroxyl group.

[0101] The molecular weight of the polyvinyl butyral resin is not particularly limited, but those having a weight average molecular weight of 5,000 to 100,000 are preferred, and 10,000 to 60,000 are more preferred. Although not particularly limited, among the above ranges, a composition (I) having a more excellent coloring suppression effect tends to be obtained with a higher weight average molecular weight of the polyvinyl butyral resin.

[0102] The glass transition temperature of the polyvinyl butyral resin is not particularly limited, but is preferably 50°C to 90°C.

[0103] -Cellulose acetate propionate resin- The cellulose acetate propionate resin (hereinafter sometimes referred to as CAP) is a resin obtained by triesterifying cellulose with acetic acid and propionic acid and then hydrolyzing it.

[0104] In 100 parts by mass of the total amount of CAP, since a composition having an excellent coloring suppression effect tends to be obtained, those having 0.3 to 2.5 parts by mass of acetyl group, 42 to 46 parts by mass of propionyl group, and 1.8 to 5 parts by mass of hydroxyl group can be preferably used.

[0105] -Cellulose acetate butyrate resin- Cellulose acetate butyrate resin (hereinafter sometimes referred to as CAB) is a resin obtained by triesterifying cellulose with acetic acid and butyric acid and then hydrolyzing it.

[0106] In 100 parts by mass of the total amount of CAB, those having an acetyl group of 2 to 30 parts by mass, a butyryl group of 17 to 53 parts by mass, and a hydroxyl group of 1 to 5 parts by mass can be preferably used because a composition having an excellent coloring suppression effect tends to be obtained.

[0107] <<<Content of Resin B in Composition (II) for Forming the Second Layer>>> The content of Resin B is, for example, 2 parts by mass or more, more preferably 4 parts by mass or more, based on 100 parts by mass of the total amount of Composition (II) for forming the second layer. Also, the content is preferably 30 parts by mass or less, more preferably 20 parts by mass or less. When the content of Resin B is at least the above lower limit value, a composition having an excellent coloring suppression effect tends to be obtained. Also, when the content of Resin B is at most the above upper limit value, a composition having excellent stability tends to be obtained. When two or more kinds of Resin B are contained, the preferable range of the above content is the total amount of the resins contained.

[0108] <<Manufacturing Method of the Composition>> The manufacturing method of Composition (I) and Composition (II) according to the present invention (Composition (I) and Composition (II) are collectively simply referred to as the composition) is not particularly limited, and a conventionally known method can be used. All the constituent components of the composition may be blended at once, or a divided blending such as making a premix by blending some components first and then blending with other components may be used. The mixing method is not particularly limited, and examples include a method of stirring and mixing with a mixer or the like, a method using a three-roll mill, and a method using a disperser such as a bead mill.

[0109] The composition according to the present invention can be used in any known and commonly used applications such as printing ink, paint, and aqueous ink for inkjet recording.

[0110] <<Printing ink>> The composition according to the present invention can be used as a printing ink for forming a printing layer. In particular, composition (I) is preferably used as a printing ink. The printing ink is not particularly limited as long as it contains the composition according to the present invention, and can be obtained with a known composition.

[0111] The printing ink may contain various additives usually contained in ordinary printing inks, such as organic or inorganic fillers, antistatic agents, defoaming agents, viscosity modifiers, polymerization inhibitors, light stabilizers, weather stabilizers, heat stabilizers, ultraviolet absorbers, antioxidants, leveling agents, pigment dispersants, waxes, etc., as required.

[0112] <<Printing on a substrate>> The printing ink using the composition according to the present invention has excellent adhesion to various substrates and can be used for printing on paper, synthetic paper, cloth, thermoplastic resin film, plastic products, steel plates, etc., and is useful as an ink for gravure printing using a gravure printing plate such as an electron engraved gravure plate or for flexographic printing using a flexographic printing plate such as a resin plate.

[0113] The film thickness of the printing ink formed by the gravure printing method or the flexographic printing method is preferably, for example, 10 μm or less, and more preferably 5 μm or less.

[0114] <Substrate> As the base material, a plastic base material is preferable, such as polyamide resins like nylon 6, nylon 66, nylon 46, polyester resins such as polyethylene terephthalate (PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, biodegradable resins such as polyhydroxycarboxylic acids like polylactic acid, aliphatic polyester resins such as poly(ethylene succinate), poly(butylene succinate), etc., polyolefin resins such as polypropylene, polyethylene, thermoplastic resins such as polyimide resins, polyarylate resins or mixtures thereof, and films made of these or laminates thereof can be mentioned. Among them, films and laminates made of polyethylene terephthalate, polyester, polyamide, polyethylene, and polypropylene can be preferably used. When emphasizing the releasability of the composition according to the present invention, polyethylene terephthalate, polypropylene, or polyethylene is more preferable. These base material films may be unstretched films or stretched films, and their manufacturing methods are not limited either. Also, the thickness of the base material film is not particularly limited, but usually, it may be in the range of 1 to 500 μm.

[0115] It is preferable that the printing surface of the base material is surface-modified by corona discharge treatment or chemical treatment, and silica, alumina, etc. may be vapor-deposited.

[0116] <Laminate> By printing the composition according to the present invention or the printing ink using the composition directly on the surface of the base material or through another layer, a film having a first layer and a second layer is laminated on the base material, and a printed matter composed of a laminate including the base material and the film can be obtained. Here, the other layer is not particularly limited and may be a single layer or a plurality of layers. For example, a third layer that promotes desorption may be arranged between the base material and the film.

[0117] <<Specific layer configuration of the laminate>> The forms of the printed matter and the laminate in the present invention are not particularly limited, and examples thereof include the following aspects. · Substrate / Ink layer (first layer) / OP varnish layer (second layer) · Substrate / Primer layer (second layer) / Ink layer (first layer) · Substrate / Ink layer 1 (second layer) / Ink layer 2 (first layer) · Substrate / Ink layer 1 (first layer) / Ink layer 2 (second layer)

[0118] As shown in the above aspects, when an ink layer composed of a first layer containing a colorant is formed on a substrate, a second layer can be formed as a varnish layer not containing a colorant. In this case, the layer undercoating the ink layer (that is, the layer between the substrate and the ink layer of the first layer) can be called a primer layer, and the layer overcoating the ink layer (that is, the layer arranged on the opposite side of the substrate with respect to the ink layer of the first layer) can be called an overprint varnish layer (OP varnish layer). In the present invention, a layer containing a colorant (for example, a colored pigment) is referred to as an ink layer, while a layer not containing the colorant is referred to as a primer layer or an OP varnish layer (both are collectively also referred to as a varnish layer). In addition, the second layer may be in a mode containing a colorant in addition to the case of not containing a colorant. For example, when the ink layer is composed of a multi-layer printing layer (for example, in the case of being composed of a white and a color layer, etc.), as shown in the above aspects, one layer may be an ink layer composed of the first layer, and the other layer may be an ink layer composed of the second layer.

[0119] In addition, a primer layer or an OP varnish layer different from the first layer and the second layer may be further provided on the ink layer composed of the first layer and the second layer. For example, the following aspects are included. · Substrate / Primer layer / Ink layer 1 (second layer) / Ink layer 2 (first layer) · Substrate / Ink layer 1 (second layer) / Ink layer 2 (first layer) / OP varnish layer

[0120] Further, a third layer (primer layer) that promotes detachment may be provided between the base material and the film. For example, the following embodiments may be mentioned. · Base material / Primer layer / Ink layer (first layer) / OP varnish layer (second layer)

[0121] Also, an OP varnish layer may be further provided on the primer layer (second layer) and the ink layer (first layer). For example, the following embodiments may be mentioned. · Base material / Primer layer (second layer) / Ink layer (first layer) / OP varnish layer

[0122] <<Varnish layer-forming composition>> Varnish layers such as the primer layer and the OP varnish layer can be formed using a varnish layer-forming composition. As the varnish layer-forming composition, generally known compositions can be applied. As described in the column of <<Specific layer configuration of the laminate>> above, when the second layer is a primer layer or an OP varnish layer, the varnish layer-forming composition for forming the primer layer or the OP varnish layer contains the resin B described above.

[0123] As the varnish layer-forming composition, in addition to the resin B, components of a varnish layer-forming composition for forming a primer layer or an OP varnish layer that is commercially available and distributed without particular limitation can be used. A general composition of the varnish layer-forming composition includes a binder resin, a solvent such as an organic solvent or an aqueous solvent, and additives.

[0124] In addition, regardless of the second layer, when a primer layer or an OP varnish layer is formed, the varnish layer-forming composition for forming the primer layer or the OP varnish layer does not contain the resin B, and a generally known composition as the varnish layer-forming composition is used.

[0125] Binder resins include, for example, cellulose resins, urethane resins, polyamide 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, petroleum resins, etc. (excluding resin B), polymerizable monomers having a carboxyl group such as itaconic acid, maleic acid, fumaric acid, cinnamic acid or their acid anhydrides, polymerizable monomers having a sulfonic acid group such as sulfonated styrene, polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide, etc., (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-(anhydrous)maleic acid resins, terpene-(anhydrous)maleic acid resins, etc., which are radical copolymers obtained by copolymerizing these polymerizable monomers, and acid-modified polyolefin resins, etc. These can be used alone or in a mixture of two or more.

[0126] The solvent may be an organic solvent or water. For example, the same organic solvents as those described in the above <<Organic Solvent>> column can be used.

[0127] Examples of additives include extender pigments, pigment dispersants, leveling agents, defoamers, waxes, plasticizers, antiblocking agents, infrared absorbers, ultraviolet absorbers, fragrances, flame retardants, etc. When the resin B is contained in the varnish layer, the addition amount may be appropriately determined within a range that does not impair the properties of the varnish layer. For example, it is preferably in the range of 0.1 to 10% by mass based on the total mass of the varnish layer composition.

[0128] In addition, a varnish layer added with a resin or low molecular compound having an acidic group can also be preferably used. As the resin or low molecular compound having an acidic group, it can be used without particular limitation as long as it can be easily mixed with the above resin B, organic solvent, etc., which are the main components of the varnish layer.

[0129] Examples of the resin having an acidic group include resins having an acid value imparted thereto, such as cellulose resins, urethane resins, polyamide 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, petroleum resins, etc., and polymerizable monomers having a carboxyl group such as itaconic acid, maleic acid, fumaric acid, cinnamic acid or their acid anhydrides, polymerizable monomers having a sulfonic acid group such as sulfonated styrene, polymerizable monomers having a sulfonamide group such as vinylbenzenesulfonamide, etc. Resins which are radical copolymers such as (meth)acrylic resins, styrene-(meth)acrylic resins, styrene-(anhydrous)maleic acid resins, terpene-(anhydrous)maleic acid resins, etc., obtained by copolymerizing the polymerizable monomers having an acidic group, and acid-modified polyolefin resins (excluding the binder resin) can be mentioned, and these can be used singly or in combination of two or more.

[0130] Examples of the low molecular compound having an acidic group preferably include organic acids such as saturated fatty acids, unsaturated fatty acids, hydroxy acids, aromatic carboxylic acids, dicarboxylic acids, tricarboxylic acids, oxocarboxylic acids, carboxylic acid derivatives, etc., and these can be used singly or in combination of two or more. Examples of saturated fatty acids include lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, capric acid, undecanoic acid, dodecanoic acid, etc. Examples of unsaturated fatty acids include oleic acid, linoleic acid, linolenic acid, arachidonic acid, eicosapentaenoic acid, docosahexaenoic acid, sorbic acid, etc. Examples of hydroxy acids include lactic acid, malic acid, citric acid, etc. Examples of aromatic carboxylic acids include benzoic acid, phthalic acid, isophthalic acid, terephthalic acid, salicylic acid, gallic acid, mellitic acid, cinnamic acid, etc. Examples of dicarboxylic acids 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 tricarboxylic acids include aconitic acid, trimer acid, etc. Examples of oxocarboxylic acids include pyruvic acid, oxaloacetic acid, etc. Examples of carboxylic acid derivatives include amino acids, nitrocarboxylic acids. These can be used alone or in combination. Also, 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.

[0131] <<Manufacture of the laminate>> The laminate according to the present invention can be manufactured, for example, by the following method. In the case where the laminate has, for example, a plastic substrate, an ink layer 1 (first layer), and an ink layer 2 (second layer) in this order, an ink layer 1 (first layer), which is a printed layer, is formed by printing a printing ink of a composition (I) for forming the first layer on the plastic substrate by a printing method such as gravure printing or flexographic printing. Next, an ink layer 2 (second layer), which is a printed layer, is formed by printing a printing ink of a composition (II) for forming the second layer on the ink layer 1 by a printing method such as gravure printing or flexographic printing. Thus, a laminate (substrate / ink layer 1 (first layer) / ink layer 2 (second layer)) can be obtained.

[0132] (Method for manufacturing a recycled substrate) In the present invention, for the printed matter of the present invention described above, a film can be detached from the substrate by an alkali solution treatment to produce a recycled substrate. "Detachment" means that the film peels off by swelling, dissolution, erosion, etc. due to alkali solution treatment. As an embodiment of the present invention, the layer directly provided on the substrate needs to have a detachment function. For example, when there is an ink layer (first layer) on the substrate, the first layer, or when a primer layer (second layer) is provided on the substrate, the second layer may have a detachment function. Since the first layer and the second layer are formed adjacent to each other, when the layer provided on the substrate detaches, other layers also detach together, and since the second layer contains resin B, coloring of the alkali solution after detachment can be suppressed. Of course, it is not intended to exclude the case where both the first layer and the second layer have a detachment function. As a preferred embodiment, for example, the first layer can be a layer having a detachment function and the second layer can be a layer not having a detachment function.

[0133] <Method for detaching a film from a substrate> As the detachment step, there is a step of immersing the printed matter in an alkali 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, preferably 40°C or higher, preferably 50°C or higher, preferably 60°C or higher, and it is more preferable to perform heating and stirring and ultrasonic vibration simultaneously.

[0134] The alkaline solution used in the separation process is not particularly limited, but preferably has a pH of 9 or higher, and an aqueous sodium hydroxide solution, an aqueous potassium hydroxide solution, an aqueous sodium hydrogen carbonate solution, an aqueous potassium hydrogen carbonate solution, an aqueous sodium dihydrogen carbonate solution, an aqueous potassium dihydrogen carbonate solution, etc. are preferred. The aqueous sodium hydroxide solution, the aqueous potassium hydroxide solution, the aqueous sodium hydrogen carbonate solution, the aqueous potassium hydrogen carbonate solution, the aqueous sodium dihydrogen carbonate solution, the aqueous potassium dihydrogen carbonate solution, etc. are preferably aqueous solutions having a concentration of 0.5% by mass to 10% by mass, and more preferably aqueous solutions having a concentration of 1% by mass to 5% by mass.

[0135] Further, the alkaline solution may 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, triethylene glycol 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, ethyl lactate, and the like. These can be used alone or in combination of two or more.

[0136] As the content ratio of the water-soluble organic solvent in the alkaline solution, 0.1 mass% to 20 mass% is preferable, and 1 mass% to 10 mass% is more preferable. Moreover, the alkaline solution may contain a water-insoluble organic solvent. Specific examples of the water-insoluble organic solvent include alcohol solvents such as n-butanol, 2-butanol, isobutanol, and octanol; aliphatic hydrocarbon solvents such as hexane, heptane, and normal paraffin; aromatic hydrocarbon solvents such as benzene, toluene, xylene, and alkylbenzene; halogenated hydrocarbon solvents such as methylene chloride, 1-chlorobutane, 2-chlorobutane, 3-chlorobutane, and carbon tetrachloride; ester solvents such as methyl acetate, ethyl acetate, and butyl acetate; ketone solvents such as methyl isobutyl ketone, methyl ethyl ketone, and cyclohexanone; and ether solvents such as ethyl ether and butyl ether. These can be used alone or in combination of two or more.

[0137] Moreover, the alkaline solution may contain a surfactant. Examples of the surfactant include various anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. Among these, anionic surfactants, nonionic surfactants, or amphoteric surfactants are preferable, and nonionic surfactants are more preferable.

[0138] Examples of anionic surfactants include alkylbenzene sulfonates, alkylphenyl sulfonates, alkylnaphthalene sulfonates, higher fatty acid salts, sulfuric acid ester salts of higher fatty acid esters, sulfonate salts of higher fatty acid esters, sulfuric acid ester salts and sulfonate salts of higher alcohol ethers, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, etc. Specific examples thereof include dodecylbenzene sulfonate, isopropylnaphthalene sulfonate, monobutylphenylphenol monosulfonate, monobutylbiphenyl sulfonate, dibutylphenylphenol disulfonate, etc.

[0139] 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 alkyl amines, polyoxyethylene fatty acid amides, fatty acid alkanolamides, alkyl alkanolamides, acetylene glycols, oxyethylene adducts of acetylene glycols, polyethylene glycol polypropylene glycol block copolymers, etc. Among these, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, fatty acid alkanolamide, acetylene glycol, oxyethylene adduct of acetylene glycol, polyethylene glycol polypropylene glycol block copolymer are preferred.

[0140] As other surfactants, silicone-based surfactants such as polysiloxane oxyethylene adducts; fluorine-based surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers; biosurfactants such as spiculisporic acid, rhamnolipid, and lysophosphatidylcholine can also be used.

[0141] These surfactants can be used alone or in combination of two or more. When adding a surfactant, the addition amount 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 in the range of 0.01 to 1% by mass based on the total amount of the alkaline solution.

[0142] When these surfactants are used, the alkaline solution after desorption tends to be more likely to be colored compared to the case of using the alkaline solution alone. However, as a film that can be detached from the substrate, by adopting the configuration of the printed matter of the present invention in which a second layer containing resin B is laminated adjacent to the first layer containing a colorant, coloring of the treatment solution can be effectively suppressed.

[0143] The alkaline solution is heated at 20 to 90 °C or vibrated by ultrasonic waves, and for example, in a treatment tank, the target printed matter or laminate is immersed. The heating method is not particularly limited, and known heating methods such as by heat rays, infrared rays, microwaves, etc. can be adopted. Also, for ultrasonic vibration, for example, a method of attaching an ultrasonic vibrator to the treatment tank and applying ultrasonic vibration to the warm water or alkaline solution can be adopted.

[0144] Also, during immersion, the alkaline solution is preferably stirred. 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, a bubbling method with an inert gas such as nitrogen gas, etc., and these may be used in combination for efficient peeling.

[0145] The time for immersing the printed matter or laminate in an alkaline solution generally ranges from 2 minutes to 48 hours, although it depends on the composition of the printed matter. In the present invention, it is not necessary for the film on the printed matter to completely peel off from the substrate. However, among 100% of the film, it is preferably 60% by mass or more, more preferably 70% by mass or more, still more preferably 80% by mass or more, and particularly preferably 90% by mass or more that peels off.

[0146] In the peeling step, the number of times of immersion in the alkaline solution may be once or divided into several times. That is, after performing the immersion once, a step of recovering the separated film substrate may be performed, or after performing the immersion several times, a step of recovering the film substrate may be performed. Further, when performing immersion a plurality of times in the peeling step, the concentration of the alkaline solution may be changed. Also, during the peeling step, known steps such as water washing and drying may be appropriately added.

[0147] Since the printed matter of the present invention forms a film in which a first layer containing a colorant and a second layer containing resin B are laminated adjacent to each other on a substrate, the coloring of the alkaline treatment solution when the film is peeled off in the peeling step can be effectively suppressed by the presence of resin B.

Examples

[0148] Hereinafter, the content and effects of the present invention will be described in more detail with reference to examples, but the present invention is not limited thereto. Note that "parts" and "%" shown below are all based on mass.

[0149] (Composition for layer formation) The compositions for layer formation used in the examples and comparative examples are as follows. [Ink composition] [[Ink A]] [Pigment] · Pigment: Phthalocyanine-based blue pigment (FASTOGEN BLUE FA5380 manufactured by DIC Corporation) [Resin] · 30% solution of nitrocellulose resin Nitrocellulose DLX5-8 manufactured by Nobel, non-volatile content 30%, ethyl acetate:IPA solution · 30% solution of urethane resin Urea urethane resin manufactured by DIC, number average molecular weight 14,000, non-volatile content 30%, ethyl acetate:IPA solution <Organic solvent> · Isopropyl alcohol · Normal propyl alcohol · Ethyl acetate · Normal propyl acetate · Methyl cyclohexane The blending ratios of the above raw materials are as shown in Table 1-1 below.

[0150] [[Ink B]] <Pigment> · Pigment: Phthalocyanine-based blue pigment (FASTOGEN BLUE FA5380 manufactured by DIC) <Resin> · 50% solution of acrylic resin Acrylic WCL-1419 manufactured by DIC, number average molecular weight 16,000, non-volatile content 50%, ethyl acetate:IPA solution · 25% solution of vinyl chloride-vinyl acetate copolymer resin Solvain A manufactured by Nisshin Chemical Industry Co., Ltd., non-volatile content 25%, methyl ethyl ketone solution · 20% solution of cellulose acetate butyrate Cellulose acetate butyrate resin (CAB-381-0.1 manufactured by Eastman Chemical), non-volatile content 20%, ethyl acetate solution <Organic solvent> · Isopropyl alcohol · Methyl ethyl ketone · Ethyl acetate · Toluene · Normal propyl acetate The blending ratios of the above raw materials are as shown in Table 1-2 below.

[0151] [[Ink C]] <Pigment> · Pigment: Phthalocyanine-based blue pigment (FASTOGEN BLUE FA5380 manufactured by DIC Corporation) <Resin> · 40% solution of nitrocellulose resin Nitrocellulose DLX5-8 manufactured by Nobel, non-volatile content 40%, dissolved in ethyl acetate:IPA · 50% solution of acrylic resin Acrylic WCL-1419 manufactured by DIC Corporation, number average molecular weight 16,000, non-volatile content 50%, dissolved in ethyl acetate:IPA <Organic solvent> · Isopropyl alcohol · Normal propyl acetate · Propylene glycol monomethyl ether The blending ratios of the above raw materials are as shown in Table 1-3 below.

[0152] [[Ink D]] <Pigment> · Pigment: Phthalocyanine-based blue pigment (FASTOGEN BLUE FA5380 manufactured by DIC Corporation) <Resin> · 30% solution of nitrocellulose resin Nitrocellulose DLX5-8 manufactured by Nobel, non-volatile content 30%, dissolved in ethyl acetate:IPA · 40% solution of polyamide resin Into a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas inlet tube, 100 parts of dimer acid (Haridimer 270S; manufactured by Harima Kasei Co., Ltd.), 1 part of tall oil fatty acid (Hartol FA-1; manufactured by Harima Kasei Co., Ltd.), 5 parts of sebacic acid, 10 parts of ethylenediamine, 5 parts of hexamethylenediamine, and 0.24 part of triphenylphosphine were added. The system was made into a nitrogen atmosphere, and then the temperature was slowly raised to 200 °C while stirring for homogenization under a nitrogen stream. Subsequently, dehydration condensation was carried out at 200 °C for 5 hours while stirring, and by adding isopropyl alcohol / industrial ethanol / methylcyclohexane (in a mass ratio of 20 / 20 / 60), a dimer acid-modified polyamide resin solution derived from tall fatty acid with a solid content of 40%, a softening point of 123 °C, an amine value of 2, an acid value of 8, and a number average molecular weight of 10,000 was obtained. <Organic solvent> · Isopropyl alcohol · Normal propyl alcohol · Methylcyclohexane · Ethylene glycol monopropyl ether The blending ratios of the above raw materials are as shown in Table 1-4 below.

[0153] [Lacquer composition] The raw materials used in Lacquer Composition 1 (also referred to as Lacquer 1) to Lacquer Composition 15 (also referred to as Lacquer 15) are as follows. <Resin> · CAB1 Cellulose acetate butyrate resin (CAB-381-0.1 manufactured by Eastman Chemical Company) · CAB2 Cellulose acetate butyrate resin (CAB-151-202 manufactured by Eastman Chemical Company), non-volatile content 30%, ethyl acetate:IPA solution · Vinyl chloride acetate 1 Vinyl chloride-vinyl acetate copolymer resin (Solvain A manufactured by Nisshin Chemical Co., Ltd.) · Vinyl chloride acetate 2 Vinyl chloride-vinyl acetate copolymer resin (Solvain A manufactured by Nisshin Chemical Co., Ltd.), non-volatile content 25%, methyl ethyl ketone solution · PVB1 Polyvinyl butyral resin (Mowital B14S manufactured by Kuraray Co., Ltd.), non-volatile content 15%, ethanol solution · PVB2 Polyvinyl butyral resin (Mowital B30H manufactured by Kuraray Co., Ltd.), non-volatile content 10%, ethanol solution · PVB3 Polyvinyl butyral resin (Mowital B60H manufactured by Kuraray Co., Ltd.), non-volatile content 10%, ethanol solution · NC1 Nitrocellulose DLX5-8 manufactured by Nobel, non-volatile content 30%, ethyl acetate:IPA solution · NC2 Nitrocellulose DLX5-8 manufactured by Nobel, non-volatile content 40%, ethyl acetate: IPA solution · Rosin Markid #1 manufactured by Arakawa Chemical Industries, Ltd. (acid value: 30 mg KOH / g, maleated rosin resin) · Polyester Polylite OD-X-240 (polyester polyol manufactured by DIC Corporation, molecular weight 2,000 · Urethane 1 Urea urethane resin manufactured by DIC, number average molecular weight 14,000 · Urethane 2 Urea urethane resin manufactured by DIC, number average molecular weight 14,000, non-volatile content 40%, ethyl acetate: IPA solution) · Urethane 3 Urea urethane resin manufactured by DIC, number average molecular weight 14,000, non-volatile content 30%, ethyl acetate: IPA solution) · Acrylic Acridic WCL-1419 manufactured by DIC, number average molecular weight 16,000, non-volatile content 50%, ethyl acetate: IPA solution

[0154] The blending ratios of the respective raw materials in Coating Compositions 1 to 15 are as shown in Table 2-1 to Table 2-3 below.

[0155] (Example 1) <Manufacture of Printed Matter> The prepared ink composition (also simply referred to as ink) was printed on a substrate in a solid pattern of 240 mm in length and 80 mm in width using a bar coater #4, and then dried with a dryer to form an ink layer. Subsequently, the prepared coating composition (also simply referred to as coating) was printed on the dried ink layer using a bar coater #4, and after printing, it was dried with a dryer to form an OP coating layer, and a printed matter having the following configuration consisting of a laminate in which an ink layer (first layer) and an OP coating layer (second layer) were laminated on the substrate was obtained. <<Configuration of Printed Matter>> · Configuration: Substrate - Ink layer (first layer) - OP coating layer (second layer) Substrate: PE film

[0156] <Evaluation Item 1: Ink Peeling Test> [Alkaline Solution] The peeling test was carried out under the following respective conditions, and the ease of peeling under each condition was compared. · 1 mass% sodium hydroxide, 0.3% surfactant, 85°C Here, a nonionic surfactant was used as the surfactant.

[0157] [Peeling Test Conditions] The peeling test was evaluated with the treatment time under each condition being 15 minutes. Note that if it peels within 5 minutes of treatment, it indicates a fairly high performance. A test piece obtained by cutting the printed matter into a size of 20 mm × 20 mm was immersed in the solution and stirred with a stirrer. After confirming the peeling state after stirring, the printed matter was rubbed with a finger to check whether the coating film peels off by rubbing. The peelability of the ink coating film under the above conditions was evaluated according to the following evaluation criteria.

[0158] [Evaluation Criteria] 5: The detachment of the ink coating film was confirmed by stirring within 5 minutes. It completely detaches when rubbed. 4: The detachment of the ink coating film was confirmed by stirring for 15 minutes. It completely detaches when rubbed. 3: The detachment of the ink coating film was not confirmed by stirring for 15 minutes. It completely detaches when rubbed. 2: The detachment of the ink coating film was not confirmed by stirring for 15 minutes. It partially detaches when rubbed. 1: The detachment of the ink coating film was not confirmed by stirring for 15 minutes. No detachment was confirmed even when rubbed.

[0159] The results of the peelability test are shown in Table 3-1 below. Note that from the perspective of practical application, an evaluation of 2 or more is required.

[0160] <Evaluation Item 2: Coloration Inhibition Test> Using the prepared printed matter, the coloration inhibition test was carried out under the following conditions.

[0161] <<Alkaline Solution>> · 1 mass% sodium hydroxide, 0.3% surfactant, 85°C Here, a nonionic surfactant was used as the surfactant.

[0162] <<Coloration suppression test conditions>> The coloration suppression test was evaluated with the treatment time of the alkaline solution being 15 minutes. Fifty test pieces obtained by cutting the printed matter into a size of 20 mm × 20 mm were immersed in 500 mL of an alkaline solution and stirred with a stirrer. In accordance with the method of JIS (Japanese Industrial Standards) K0102, the transparency of the alkaline solution after stirring was measured with a transparency meter.

[0163] Specifically, an alkaline solution was filled in a glass cylinder with a lower opening and graduations every 10 mm, equipped with a marker plate marked with a double cross at the bottom. Looking through from the top to the bottom, the scale of the water surface when the sample was quickly drained from the lower opening until the double cross of the marker plate could be clearly identified for the first time was read. This was repeated twice, and the average value was obtained and expressed in degrees (10 mm is 1 degree) as the transparency. Evaluation was carried out according to the following evaluation criteria.

[0164] Note that, as the blank samples for Examples 1 to 13, 50 test pieces cut into a size of 20 mm × 20 mm of the printed matter obtained with the ink composition of Comparative Example 1 were immersed in 500 mL of an alkaline solution and stirred with a stirrer, and then the samples were used. As the blank sample for Example 14, 50 test pieces cut into a size of 20 mm × 20 mm of the printed matter obtained with the ink composition of Comparative Example 4 were immersed in 500 mL of an alkaline solution and stirred with a stirrer, and then the samples were used. As the blank samples for Examples 15 to 27, 50 test pieces cut into a size of 20 mm × 20 mm of the printed matter obtained with the ink composition of Comparative Example 5 were immersed in 500 mL of an alkaline solution and stirred with a stirrer, and then the samples were used. As the blank samples for Examples 28 to 40, 50 test pieces cut into a size of 20 mm × 20 mm of the printed matter obtained with the ink composition of Comparative Example 8 were immersed in 500 mL of an alkaline solution and stirred with a stirrer, and then the samples were used. As the blank samples for Examples 41 to 53, 50 test pieces cut into a size of 20 mm × 20 mm of the printed matter obtained with the ink composition of Comparative Example 11 were immersed in 500 mL of an alkaline solution and stirred with a stirrer, and then the samples were used.

[0165] [Evaluation Criteria] 5: Transparency more than 10 times that of the blank sample. 4: Transparency 5 times or more that of the blank sample. 3: Transparency 3 times or more that of the blank sample. 2: Transparency 1.5 times or more that of the blank sample. 1: Transparency equivalent to that of the blank sample.

[0166] The results of the coloring suppression test are shown in Table 3-1 below. Note that from the perspective of practical application, an evaluation of 3 or more is required.

[0167] (Examples 2 to 53, Comparative Examples 1 to 13) In Example 1, a printed matter was obtained in the same manner as in Example 1, except that the layer structure was changed to those shown in Tables 3-1 to 3-9 below. For the obtained printed matter, evaluation was conducted in the same manner as in Example 1. The results are shown in Tables 3-1 to 3-9. In addition, for Example 14 and Comparative Example 4, the prepared varnish composition was printed on the substrate using a bar coater #4 in the same manner as in Example 1. After printing, it was dried with a dryer to form a primer layer. Subsequently, the prepared ink composition was printed on the dried primer layer using a bar coater #4, and after printing, it was dried with a dryer to form an ink layer, obtaining a printed matter having the following configuration composed of a laminate in which a primer layer (second layer) and an ink layer (first layer) were laminated in this order on the substrate. <<Configuration of Printed Matter>> · Configuration: Substrate - Primer Layer (Second Layer) - Ink Layer (First Layer) Substrate: PE film

[0168]

Table 1-1

[0169]

Table 1-2

[0170]

Table 1-3

[0171]

Table 1-4

[0172]

Table 2-1

[0173]

Table 2-2

[0174]

Table 2-3

[0175]

Table 3-1

[0176]

Table 3-2

[0177]

Table 3-3

[0178]

Table 3-4

[0179]

Table 3-5

[0180]

Table 3-6

[0181]

Table 3-7

[0182]

Table 3-8

[0183]

Table 3-9

[0184] The printed matter of the example has a film that can be easily detached from the substrate by treatment with an alkaline solution, and it can be seen that the film has an excellent coloring suppression effect against the coloring of the treatment liquid of the alkaline solution.

Claims

1. A printed matter comprising a laminate of a substrate and a film that can be detached from the substrate by treatment with an alkaline solution, wherein the film has a first layer containing a colorant and at least one resin A selected from the group consisting of an acrylic resin, a urethane resin, a polyamide resin, a rosin resin, and a polyester resin, and a second layer in contact with the first layer, the second layer contains at least one resin B selected from the group consisting of a vinyl chloride-vinyl acetate copolymer resin, a polyvinyl butyral resin, a cellulose acetate propionate resin, and a cellulose acetate butyrate resin, the content ratio of the resin B in the second layer is 30% by mass or more based on the total amount of the resins contained in the second layer, the first layer is (i) containing at least a urethane resin and a nitrocellulose resin, (ii) containing at least an acrylic resin and a nitrocellulose resin, (iii) containing at least a polyamide resin and a nitrocellulose resin, and (iv) containing at least an acrylic resin, a vinyl chloride-vinyl acetate copolymer resin, and a cellulose acetate butyrate resin, any one of which is a printed matter.

2. The printed matter according to claim 1, wherein a third layer for promoting detachment is further provided between the substrate and the film.

3. A method for producing a recycled substrate, wherein the film is detached from the substrate by treatment with an alkaline solution with respect to the printed matter according to claim 1 to obtain a recycled substrate.

4. The method for producing a recycled substrate according to claim 3, wherein the alkaline solution has a pH of 9 or more and contains a nonionic surfactant.

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