WO2023063090A1

WO2023063090A1 - Printed matter and laminate layered product

Info

Publication number: WO2023063090A1
Application number: PCT/JP2022/036337
Authority: WO
Inventors: 帆南美山本; 朋美浅見; 瑠璃青木; 義久白崎; 健太郎永川
Original assignee: Dic株式会社
Priority date: 2021-10-14
Filing date: 2022-09-29
Publication date: 2023-04-20
Also published as: JPWO2023063090A1; JP7405308B2

Abstract

The present invention pertains to a multilayer printed matter that is obtained by layering, on a film base, a white print layer having a white pigment, and a color print layer having at least one pigment other than the white pigment, and is characterized in that the at least one pigment other than the white pigment contains at least 200 ppm of the element iron with respect to 100 parts by mass of the pigment, and the white pigment contains less than 200 ppm of the element iron with respect to 100 parts by mass of the white pigment. According to the present invention, it is possible to provide a printed matter that has basic properties such as dispersibility, fluidity, and stability for ink, that has excellent adhesive properties, and in which the whiteness of the white color of the white print layer is maintained.

Description

Printed matter and laminated laminate

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

Gravure inks and flexo inks are widely used for the purpose of imparting aesthetics and functionality to printed materials. When a gravure or flexographic printed material is used as a packaging material, particularly as a food packaging material, it is generally subjected to lamination. In this case, various printing materials and lamination processes are used depending on the type of contents and purpose of use.

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

In recent years, the use of aromatic solvents such as toluene and ketone solvents such as methyl ethyl ketone has been restricted due to both work hygiene during printing and the toxicity of packaging materials. For example, Patent Document 1 describes a non-laminating ink composition for flexible packaging containing, as essential components, a polypropylene glycol-containing polyurethane resin and a vinyl chloride-vinyl acetate copolymer resin having a hydroxyl group.

Furthermore, the laws and regulations surrounding food packaging materials in particular have become stricter worldwide, and in recent years, regulations on ingredients used in packages and their migration into food are becoming stricter. In recent years, the movement away from plastics has accelerated, and the demand for recyclability of packages is increasing. In the development of ink products for packaging, etc., it is necessary to design inks and packaging constituent materials using materials that ensure safety to the human body and the environment.

In this trend, PVC has the following problems, and there are concerns about it as a substance that hinders the recycling of packages. The first is the issue of chemical recycling. Various types of plastics are included in plastic waste discharged as general waste, including chlorinated resins such as polyvinyl chloride and polyvinylidene chloride. Hydrogen chloride is desorbed from these chlorine-based resins in the thermal decomposition process of recycling to generate hydrochloric acid, which causes corrosion of equipment and piping. Secondly, there is the issue of thermal recycling. In the method of reusing the energy generated when the waste is incinerated, there is a problem that environmental hormones such as dioxin are discharged when chlorine-based resin is included in the incineration. Therefore, it is desired to develop an ink which does not use chlorine-based materials such as PVC and which has various physical properties required for laminating ink.

However, with the recent diversification of packaging base materials, printing inks used for decoration or surface protection are required to have advanced performance and adaptability to various films. For example, among packaging materials, when used as a soft packaging material for foodstuffs or sanitary goods, lamination is generally added. In this case, various printing materials and lamination processes are used depending on the type of contents and purpose of use. In addition, printed matter used for flexible packaging generally has a plurality of printed layers, and a printed layer containing a white pigment as a background and a printed layer with a colored pigment that forms a pattern are laminated on a film. The compatibility between the film and each printed layer is also important. Therefore, in addition to the basic properties as an ink such as dispersibility, fluidity and printability, it also has improved adhesion to various substrates, laminate strength, and retort suitability, and is free of chlorine-based resins as a binder. It is by no means easy to improve environmental responsiveness by realizing

On the other hand, in order to speed up the wettability of the pigment to the solvent and improve the dispersibility, the use of a pigment whose surface has been treated with an iron salt has been studied (see Patent Documents 2 and 3). Printing inks using pigments with such excellent dispersibility are expected to be able to maintain or improve basic ink properties such as dispersibility, fluidity, and printability regardless of the type of binder. It is

JP 2005-298618 A JP 2019-173037 A Japanese Patent Application Laid-Open No. 2020-84026

The inventors of the present invention have conducted various studies on the application of various pigments using the techniques described in Patent Documents 2 and 3 to printed matter having a plurality of printed layers and laminated laminates. As a result, it was found that when a white printed layer was formed using a specific white pigment, the white printed layer was tinged with yellow, resulting in loss of whiteness in the white color.

Therefore, the problem to be solved by the present invention is to maintain the whiteness of the white printed layer without impairing the basic characteristics of the ink such as dispersibility, fluidity, and stability, and to improve environmental safety. The purpose is to provide excellent printed matter.

The present inventors have made intensive studies in order to solve the above problems, and found that using specific pigments for each of the color printed layer and the white printed layer in a printed matter having a plurality of printed layers is effective for solving the problem. Found it.

That is, the present invention provides a multilayer printed matter in which a white printed layer having a white pigment and at least one color printed layer having a pigment other than the white pigment are laminated on a film substrate,
At least one pigment other than the white pigment contains 200 ppm or more of iron element per 100 parts by mass of the pigment,
The white pigment relates to printed matter containing less than 200 ppm of elemental iron per 100 parts by weight of white pigment.

Furthermore, the present invention relates to a laminate having the printed matter.

According to the present invention, it is possible to obtain a printed matter in which the whiteness of the white printed layer is maintained while having the basic properties of ink such as dispersibility, fluidity, stability and adhesion. In addition, the printed material of the present invention has excellent ink properties such as dispersibility, fluidity, and stability even if it does not contain a chlorine-based resin as a resin used in the printing ink, so it is excellent in environmental safety. You get a print.

The present invention will be explained in detail.

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

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

The printed matter of the present invention is a multi-layered printed matter in which a white printed layer containing a white pigment and a color printed layer containing at least one pigment other than the white pigment are laminated. The white printed layer is formed from a liquid ink composition containing a white pigment, and the color printed layer is formed from a liquid ink composition containing a pigment other than the white pigment.

<Liquid ink composition containing pigment (color pigment) other than white pigment>
A liquid ink composition containing a coloring pigment contains a coloring pigment, a binder resin, an organic solvent, water and various additives as necessary.

(coloring pigment)
The liquid ink composition forming the color print layer contains at least a pigment (color pigment) other than the white pigment containing 200 ppm or more of iron element per 100 parts by mass of the pigment. The coloring pigment used in the color printing layer of the present invention can improve the dispersion stability of the ink using this pigment by subjecting the surface of the pigment particles to iron element introduction treatment.

The coloring pigment is not particularly limited as long as it is other than the white pigment described later, and examples include inorganic pigments and organic pigments used in general inks, paints, recording agents, and the like. Examples of organic pigments include condensed polycyclic organic pigments having a cyclic structure having a benzene ring or a heterocyclic ring, and azo pigments. Specific examples of preferred organic pigments are given below.

The azo pigment may be any organic pigment having an azo group (-N=N-) in the molecule, and may be any of soluble azo lake pigments, insoluble azo pigments, and condensed azo pigments. Examples of azo pigments include C.I. I. Pigment Red 10, C.I. I. Pigment Red 11, C.I. I. Pigment Red 112, C.I. I. Pigment Red 114, C.I. I. Pigment Red 119, C.I. I. Pigment Red 12, C.I. I. Pigment Red 136, C.I. I. Pigment Red 14, C.I. I. Pigment Red 144, C.I. I. Pigment Red 146, C.I. I. Pigment Red 147, C.I. I. Pigment Red 15, C.I. I. Pigment Red 150, C.I. I. Pigment Red 16, C.I. I. Pigment Red 164, C.I. I. Pigment Red 166, C.I. I. Pigment Red 17, C.I. I. Pigment Red 170, C.I. I. Pigment Red 171, C.I. I. Pigment Red 175, C.I. I. Pigment Red 176, C.I. I. Pigment Red 18, C.I. I. Pigment Red 183, C.I. I. Pigment Red 184, C.I. I. Pigment Red 185, C.I. I. Pigment Red 187, C.I. I. Pigment Red 188, C.I. I. Pigment Red 193, C.I. I. Pigment Red 2, C.I. I. Pigment Red 200, C.I. I. Pigment Red 208, C.I. I. Pigment Red 21, C.I. I. Pigment Red 210, C.I. I. Pigment Red 211, C.I. I. Pigment Red 213, C.I. I. Pigment Red 214, C.I. I. Pigment Red 22, C.I. I. Pigment Red 220, C.I. I. Pigment Red 221, C.I. I. Pigment Red 23, C.I. I. Pigment Red 237, C.I. I. Pigment Red 238, C.I. I. Pigment Red 239, C.I. I. Pigment Red 242, C.I. I. Pigment Red 243, C.I. I. Pigment Red 245, C.I. I. Pigment Red 247, C.I. I. Pigment Red 253, C.I. I. Pigment Red 256, C.I. I. Pigment Red 258, C.I. I. Pigment Red 266, C.I. I. Pigment Red 268, C.I. I. Pigment Red 269, C.I. I. Pigment Red 3, C.I. I. Pigment Red 31, C.I. I. Pigment Red 32, C.I. I. Pigment Red 38, C.I. I. Pigment Red 4, C.I. I. Pigment Red 41, C.I. I. Pigment Red 48, C.I. I. Pigment Red 48:1, C.I. I. Pigment Red 48:2, C.I. I. Pigment Red 48:3, C.I. I. Pigment Red 48:4, C.I. I. Pigment Red 49, C.I. I. Pigment Red 49:1, C.I. I. Pigment Red 49:2, C.I. I. Pigment Red 5, C.I. I. Pigment Red 50:1, C.I. I. Pigment Red 52:1, C.I. I. Pigment Red 52:2, C.I. I. Pigment Red 53:1, C.I. I. Pigment Red 54, C.I. I. Pigment Red 57:1, C.I. I. Pigment Red 58, C.I. I. Pigment Red 58:4, C.I. I. Pigment Red 6, C.I. I. Pigment Red 60, C.I. I. Pigment Red 60:1, C.I. I. Pigment Red 63, C.I. I. Pigment Red 63:1, C.I. I. Pigment Red 63:2, C.I. I. Pigment Red 64:1, C.I. I. Pigment Red 68, C.I. I. Pigment Red 7, C.I. I. Pigment Red 8, C.I. I. Pigment Red 9, C.I. I. Pigment Red 95, C.I. I. Pigment Yellow 1, C.I. I. Pigment Yellow 10, C.I. I. Pigment Yellow 100, C.I. I. Pigment Yellow 104, C.I. I. Pigment Yellow 105, C.I. I. Pigment Yellow 106, C.I. I. Pigment Yellow 111, C.I. I. Pigment Yellow 113, C.I. I. Pigment Yellow 114, C.I. I. Pigment Yellow 116, C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 120, C.I. I. Pigment Yellow 124, C.I. I. Pigment Yellow 126, C.I. I. Pigment Yellow 127, C.I. I. Pigment Yellow 128, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 130, C.I. I. Pigment Yellow 133, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 15, C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 152, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 155, C.I. I. Pigment Yellow 16, C.I. I. Pigment Yellow 165, C.I. I. Pigment Yellow 166, C.I. I. Pigment Yellow 167, C.I. I. Pigment Yellow 168, C.I. I. Pigment Yellow 169, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 170, C.I. I. Pigment Yellow 172, C.I. I. Pigment Yellow 174, C.I. I. Pigment Yellow 175, C.I. I. Pigment Yellow 176, C.I. I. Pigment Yellow 180, C.I. I. Pigment Yellow 181, C.I. I. Pigment Yellow 183, C.I. I. Pigment Yellow 191, C.I. I. Pigment Yellow 191:1, C.I. I. Pigment Yellow 194, C.I. I. Pigment Yellow 2, C.I. I. Pigment Yellow 205, C.I. I. Pigment Yellow 206, C.I. I. Pigment Yellow 209, C.I. I. Pigment Yellow 212, C.I. I. Pigment Yellow 214, C.I. I. Pigment Yellow 219, C.I. I. Pigment Yellow 3, C.I. I. Pigment Yellow 4, C.I. I. Pigment Yellow 49, C.I. I. Pigment Yellow 5, C.I. I. Pigment Yellow 55, C.I. I. Pigment Yellow 6, C.I. I. Pigment Yellow 60, C.I. I. Pigment Yellow 61, C.I. I. Pigment Yellow 62, C.I. I. Pigment Yellow 63, C.I. I. Pigment Yellow 65, C.I. I. Pigment Yellow 7, C.I. I. Pigment Yellow 73, C.I. I. Pigment Yellow 74, C.I. I. Pigment Yellow 75, C.I. I. Pigment Yellow 77, C.I. I. Pigment Yellow 81, C.I. I. Pigment Yellow 83, C.I. I. Pigment Yellow 87, C.I. I. Pigment Yellow 9, C.I. I. Pigment Yellow 93, C.I. I. Pigment Yellow 94, C.I. I. Pigment Yellow 95, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 98, C.I. I. Pigment Orange 1, C.I. I. Pigment Orange 13, C.I. I. Pigment Orange 15, C.I. I. Pigment Orange 16, C.I. I. Pigment Orange 17, C.I. I. Pigment Orange 17:1, C.I. I. Pigment Orange 19, C.I. I. Pigment Orange 2, C.I. I. Pigment Orange 22, C.I. I. Pigment Orange 24, C.I. I. Pigment Orange 3, C.I. I. Pigment Orange 34, C.I. I. Pigment Orange 36, C.I. I. Pigment Orange 38, C.I. I. Pigment Orange 4, C.I. I. Pigment Orange 46, C.I. I. Pigment Orange 5, C.I. I. Pigment Orange 60, C.I. I. Pigment Orange 62, C.I. I. Pigment Orange 64, C.I. I. Pigment Orange 72, C.I. I. Pigment Orange 74, C.I. I. Pigment Brown 25, C.I. I. Pigment Brown 32, C.I. I. Pigment Brown 5, C.I. I. Pigment Blue 25, C.I. I. Pigment Blue 26, C.I. I. Pigment Violet 13, C.I. I. Pigment Violet 17, C.I. I. Pigment Violet 32, C.I. I. Pigment Violet 50 may be mentioned, and may be used alone or in combination.

Among azo pigments, C.I. I. Pigment Red 57:1 (PR57:1), C.I. I. Pigment Red 146 (PR146), C.I. I. Pigment Yellow 13 (PY13), C.I. I. Pigment Yellow 55 (PY55), C.I. I. Pigment Yellow 83 (PY83), C.I. I. Pigment Yellow 180 (PY180), C.I. I. Pigment Range 13 (PO13) is preferred.

The primary particle size of the azo pigment is, for example, 0.01 to 1.0 μm, preferably 0.1 to 0.6 μm. Further, the specific surface area of the azo pigment is, for example, 10 to 150 m2/g, preferably 20 to 100 m2/g. When the primary particle size and specific surface area are within the above ranges, the pigment can have excellent coloring power and dispersibility.

In addition, as a coloring pigment, a condensed polycyclic organic pigment can also be mentioned. Among organic pigments, the condensed polycyclic organic pigment means an organic pigment having a cyclic structure having a benzene ring or a heterocyclic ring. Examples of condensed polycyclic organic pigments used in the present invention include C.I. I. Pigment Blue 15, C.I. I. Pigment Blue 15:1, C.I. I. Pigment Blue 15:2, C.I. I. Pigment Blue 15:3, C.I. I. Pigment Blue 15:4, C.I. I. Pigment Blue 15:5, C.I. I. Pigment Blue 15:6, C.I. I. Pigment Blue 16, C.I. I. Pigment Blue 17, C.I. I. Pigment Blue 75, C.I. I. Pigment Blue 79, C.I. I. Pigment Green 7, C.I. I. Pigment Green 36, C.I. I. Pigment Green 58, C.I. I. Pigment Green 59, C.I. I. Pigment Green 62, C.I. I. Pigment Green 63 and other phthalocyanine pigments, C.I. I. Pigment Violet 19, C.I. I. Pigment Violet 42, C.I. I. Pigment Violet 55, C.I. I. Pigment Red 122, C.I. I. Pigment Red 202, C.I. I. Pigment Red 206, C.I. I. Pigment Red 207, C.I. I. Pigment Red 209, C.I. I. Pigment Orange 48, C.I. I. Pigment Orange 49 and other quinacridone pigments, C.I. I. Pigment Violet 23, C.I. I. Pigment Violet 34, C.I. I. Pigment Violet 35, C.I. I. Pigment Violet 37, C.I. I. Pigment Blue 80 and other dioxazine pigments, C.I. I. Pigment Red 123, C.I. I. Pigment Red 149, C.I. I. Pigment Red 178, C.I. I. Pigment Red 179, C.I. I. Pigment Red 190, C.I. I. Pigment Red 224, C.I. I. Pigment Violet 29, C.I. I. Pigment Black 31, C.I. I. Pigment Black 32 and other perylene pigments, C.I. I. Pigment Orange 43, C.I. I. Pigment Red 194 and other perinone pigments, C.I. I. Pigment Yellow 109, C.I. I. Pigment Yellow 110, C.I. I. Pigment Yellow 173, C.I. I. Pigment Yellow 179, C.I. I. Pigment Orange 61, C.I. I. Pigment Brown 38 and other isoindolinone pigments, C.I. I. Pigment Yellow 139, C.I. I. Pigment Yellow 185, C.I. I. Pigment Orange 66, C.I. I. Pigment Orange 69, C.I. I. Pigment Red 260 and other isoindoline pigments, C.I. I. Pigment Red 88, C.I. I. Pigment Red 181, C.I. I. Pigment Red 279, C.I. I. Pigment Violet 36, C.I. I. Pigment Violet 38 and other thioindigo pigments, C.I. I. Pigment Red 83, C.I. I. Pigment Red 89, C.I. I. Pigment Red 168, C.I. I. Pigment Red 177, C.I. I. Pigment Red 182, C.I. I. Pigment Red 216, C.I. I. Pigment Red 226, C.I. I. Pigment Red 251, C.I. I. Pigment Red 263, C.I. I. Pigment Blue 60, C.I. I. Pigment Yellow 24, C.I. I. Pigment Yellow 99, C.I. I. Pigment Yellow 108, C.I. I. Pigment Yellow 123, C.I. I. Pigment Yellow 199, C.I. I. Pigment Violet 31, C.I. I. Pigment Orange 40, C.I. I. Pigment Orange 51, C.I. I. Pigment Violet 5:1, C.I. I. Pigment Black 20 and other anthraquinone pigments, C.I. I. Pigment Yellow 138, C.I. I. Pigment Yellow 231 and other quinophthalone pigments, C.I. I. Pigment Orange 71, C.I. I. Pigment Orange 73, C.I. I. Pigment Orange 81, C.I. I. Pigment Red 254, C.I. I. Pigment Red 255, C.I. I. Pigment Red 264, C.I. I. Pigment Red 270, C.I. I. Pigment Red 272 and other diketopyrrolopyrrole pigments, C.I. I. Pigment Yellow 117, C.I. I. Pigment Yellow 129, C.I. I. Pigment Yellow 150, C.I. I. Pigment Yellow 153, C.I. I. Pigment Orange 65, C.I. I. Pigment Orange 68, C.I. I. Pigment Red 257, C.I. I. Pigment Red 271, C.I. I. Pigment Green 8, C.I. I. Metal complex pigments such as Pigment Green 10 and the like are included.

As the condensed polycyclic organic pigment used in the present invention, a commercially available product may be used, or it may be produced by a known and commonly used method and used. Of course, it may be used by appropriately adding known treatments after production, for example, pigment derivative treatment, surfactant treatment, rosin treatment, and resin treatment may be added before use. Furthermore, the pigment particle size, particle morphology, and particle surface charge may be adjusted and controlled for printing inks, paints, colored moldings, stationery, textile printing, toners, color filters, inkjet inks, and cosmetics. When a condensed polycyclic organic pigment with a high specific surface area by the BET method is used for ink, the viscosity of the ink increases, and when the specific surface area is low, the coloring power of the ink decreases. The specific surface area according to the method is preferably in the range of 20 to 130 m ² /g, more preferably in the range of 50 to 100 m ² /g.

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

Commercially available carbon black can be used as carbon black, and usable carbon black is not particularly limited, and oil furnace black, gas furnace black, channel black, channel black, produced by contact method, furnace method, thermal method, etc. Various commercially available products such as acetylene black may be used. The particle size of carbon black is, for example, 5 to 200 nm, preferably 20 to 50 nm. The nitrogen adsorption specific surface area of carbon black is, for example, 20 to 500 m ² /g, preferably 30 to 150 m ² /g. Carbon black has a DBP oil absorption of, for example, 20 to 150 cm ³ /100 g, preferably 30 to 120 cm ³ /100 g. Volatile content of carbon black is, for example, 0.1 to 10.0%. The pH value of carbon black is, for example, 1-10, preferably 2-.

Examples of the commercially available carbon black include MA7, 8, 11, 77, 100, 100R, 100S, 220, 230, 600, #650, #750, #40, #44B, #44, #45B, # 47, #45, #33, #45L, #47, #50, #52, #2700, #2650, #2600, #200, #2350, #2300, #2200, #1000, #990, #980, #970, #960, #950, #900, #850, #32, #30, #25, #20, #10, #5, CF9, #95, #260 (manufactured by Mitsubishi Chemical Corporation), " Special Black6, 5, 4A, 4, 101, 550, 350, 250, 100", "Printex U, 150T, V, 140V, 140U", "PrintX P, L6, L, G, ES23, ES22, A, 95 , 90, 85, 80, 75, 60, 55, 45, 40, 35, 300, 30, 3, 25, 200", "Color Black S170, S160, FW2V, FW200, FW2, FW18, FW1" (Orion Engineered Carbons), "Black Pearls 1000M, 800, 880, 4630", "Monarch 1300, 700, 880, 4630", "Regal 330R, 660R, 660, 400R, 415R, 415", "MOGUL E, L ” (manufactured by Cabot Corporation), “Raven 7000, 3500, 5250, 5750, 5000ULTRAII, 1255, 1250, 1190, 1000, 1020, 1035, 1100ULTRA, 1170, 1200” (manufactured by Columbian Chemicals), “SUNBLACK SB200, 210, 220, 230, 240, 250, 260, 270, 280, 300, 305, 320, 400, 410, 600, 700, 705, 710, 715, 720, 725, 805, 900, 910, 935, 960" (manufactured by Asahi Carbon Co., Ltd.), Toka Black #8500, #8500F, #7550SB, #7550F" (manufactured by Tokai Carbon Co., Ltd.).

A coloring pigment containing 200 ppm or more of iron element per 100 parts by mass of pigment is obtained by adding the above-mentioned coloring pigment to a solvent and stirring to obtain a pigment slurry, and adding an iron compound and an oxidizing agent to the pigment slurry and stirring. It is obtained through a pigment surface treatment step of treating the surface of the pigment and a step of filtering the reaction solution and drying and pulverizing the filtrate.

Water and/or an organic solvent can be used as the solvent, and methanol, ethanol, n-propanol, i-propanol, etc. can be used as the organic solvent. Water is particularly preferred from the point of view of economy. The water may be pure water or industrial water, and furthermore, acetate buffer, phosphate buffer, citrate buffer, citrate phosphate buffer, borate buffer, tartrate buffer. You may use buffers, such as.

The amount of the coloring pigment to be added as a raw material is preferably 1 to 30 parts by mass with respect to 100 parts by mass of the solvent. When the amount added is small, the productivity is low. 2 to 20 parts by mass is more preferable, and 3 to 12 parts by mass is particularly preferable.

As iron compounds, iron sulfate, iron chloride, iron fluoride, iron bromide, iron iodide, iron nitrate, iron phosphate, iron borate, iron carbonate, iron acetate, etc. can be used. Iron sulfate, iron chloride, and iron nitrate are preferred from the point of view of economy. As iron, bivalent or trivalent iron can be used. Also, the iron compound may be either an anhydride or a hydrate.

The temperature in the pigment slurry manufacturing process is preferably 0°C to 100°C. The temperature in the pigment surface treatment step is preferably 0° C. to 100° C. Since the reaction rate of the pigment surface treatment reaction is slow at low temperatures and the decomposition of hydrogen peroxide is promoted at high temperatures, 10° C. to 90° C. is preferred. More preferably, 20°C to 80°C is particularly preferred.

The reaction time for the pigment surface treatment step is preferably 10 minutes to 2 hours.

The pH of the treatment liquid in the pigment surface treatment step is preferably pH 1 to 7, since iron ions are precipitated due to alkalinity.

As the oxidizing agent, hydrogen peroxide, permanganate, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, peroxodisulfate, chromic acid, dichromic acid, ozone, etc. can be used. As the oxidizing agent, hydrogen peroxide diluted with water to a concentration of 20 to 50% by mass is preferred. The amount of the oxidizing agent to be used may vary depending on the concentration as long as it is suitable for the oxidation reaction.

The iron compound is preferably added in an amount of 1 to 30% by mass, preferably 2 to 15% by mass, based on the raw condensed polycyclic organic pigment.

The iron compound and the oxidizing agent may be added to the pigment slurry at the same time or separately. When they are added at the same time, the iron compound and the oxidizing agent may be mixed in advance and then added. When adding them separately, the iron compound may be added first, or the oxidizing agent may be added first. Also, the oxidizing agent may be added dropwise, or may be added all at once.

In the colored pigment obtained by the above treatment, iron is introduced onto the surface of the pigment and contains 200 ppm or more of elemental iron per 100 parts by mass of the pigment. The surface of the coloring pigment particles of the present invention is covered with an iron-containing compound, and by increasing the hydrophilicity of the particle surface compared to an untreated pigment, the wettability to solvents increases, the wettability increases, and the dispersibility improves. presumed to be excellent.

The surface-treated coloring pigment preferably contains 200 ppm or more of iron element per 100 parts by mass of the coloring pigment, preferably 230 ppm or more, more preferably 500 ppm or more, and more preferably 1000 ppm or more. . The upper limit of the iron element contained in the coloring pigment is not particularly limited, but the iron element content is preferably 20000 ppm or less, more preferably 18000 ppm or less, and even more preferably 15000 ppm or less per 100 parts by mass. More specifically, when an azo pigment is used, the iron element content is preferably 200 ppm or more, preferably 500 ppm or more, more preferably 1000 ppm or more, and 3000 ppm or more per 100 parts by mass of the azo pigment. It is more preferable to On the other hand, the iron element content is preferably 20000 ppm or less, more preferably 18000 ppm or less, and even more preferably 15000 ppm or less per 100 parts by mass of the azo pigment. Further, when carbon black is used, it preferably contains 200 ppm or more of iron element per 100 parts by mass of carbon black, preferably 500 ppm or more, more preferably 1000 ppm or more, and 3000 ppm or more. It is more preferable. On the other hand, the iron element content is preferably 20000 ppm or less, more preferably 18000 ppm or less, and even more preferably 15000 ppm or less per 100 parts by mass of carbon black.

The iron element is not limited to iron alone (Fe), but may be in the form of iron compounds such as iron oxides (FeO _, _Fe2O3, etc.) and iron hydroxides (Fe(OH) ₂ , Fe(OH) ₃ , etc.). may The above content of elemental iron can be measured as the amount of elemental iron even in such an iron compound.

In addition, in the present invention, the amount of iron element contained in the coloring pigment can be measured using an energy dispersive X-ray fluorescent spectrometer, PANalytical Epsilon 5 (manufactured by Spectris Co., Ltd.).

The color pigment used in the present invention preferably has a base adsorption amount of 0.30 μmol/m ² or more per surface area of the pigment in order to enhance dispersibility in a solvent. The base adsorption amount per surface area of the pigment is more preferably 0.35 μmol/m ² or more, more preferably 0.40 μmol/m ² or more, and more preferably 0.50 μmol/m ² or more. is more preferably 0.60 μmol/m ² or more, more preferably 0.75 μmol/m ² or more, and even more preferably 1 μmol/m ² or more. On the other hand, the upper limit of the base adsorption amount is not particularly limited, but is preferably 2.00 μmol/m ² or more.

The amount of base adsorption contained in the pigment is measured by, for example, adding the pigment to a certain amount of basic solution, allowing the pigment to adsorb the base, and then centrifuging the pigment to settle the pigment and collecting the supernatant solution. The amount of base adsorbed per weight of the pigment can be calculated by subtracting the amount of base from the amount of base initially added as the amount of unadsorbed base. The base adsorption amount per surface area can be calculated by dividing the base adsorption amount per weight by the nitrogen adsorption specific surface area.

The amount of the pigment is sufficient to ensure the concentration and coloring power of the liquid ink composition, that is, 1 to 60% by mass of the total mass of the ink, and 10 to 90% by mass of the solid content in the ink. is preferably included in Moreover, a coloring agent can be used individually or in combination of 2 or more types.

(binder resin)
The binder resin is not particularly limited as long as it is usually used for liquid inks such as gravure inks and flexographic inks that are applied to printing methods using printing plates. Examples of resins include polyurethane resins, vinyl chloride-vinyl acetate copolymer resins, chlorinated polypropylene resins, ethylene-vinyl acetate copolymer resins, vinyl acetate resins, polyamide resins, acrylic resins, polyester resins, alkyd resins, Polyvinyl chloride resins, rosin-based resins, rosin-modified maleic acid resins, ketone resins, cyclized rubbers, chlorinated rubbers, polyvinyl butyral resins, petroleum resins and the like can be mentioned. These resins can be used alone or in combination of two or more. Among them, it is preferable to use a polyurethane resin as the main binder resin because of its excellent adhesion to film substrates, blocking resistance, lamination suitability, and highlight transferability. The ratio of the urethane resin to the total amount of resin in the ink is preferably 50% by mass or more, preferably 60% by mass or more.

On the other hand, since the color printing layer of the present invention uses a coloring pigment containing 200 ppm or more of iron element per 100 parts by mass of the coloring pigment, stable ink dispersibility and fluidity can be obtained regardless of the type of binder resin. be done. Therefore, the safety to the environment and the human body can be improved by using an ink composition that does not use chlorine-based resins such as vinyl chloride-vinyl acetate copolymer resins. At least one resin selected from polyurethane resins, maleic acid resins, cellulose resins, polyester resins, acrylic resins, polyamide resins, and polyvinyl butyral resins from the viewpoint of achieving both safety and excellent ink dispersibility and fluidity. It is preferable to contain It is also preferable to use a biomass-derived material such as biomass urethane resin.

(polyurethane resin)
The polyurethane resin is not particularly limited as long as it is a polyurethane resin obtained by reacting a polyol and a polyisocyanate. As the polyol, it is preferable to use a polyester polyol, and it is preferable to use a polyester polyol and a polyether polyol.

The polyester polyol is preferably a polyester polyol obtained by dehydration condensation or polymerization of a low-molecular-weight polyol and a polyvalent carboxylic acid or an anhydride thereof. By introducing an ester group into the polyester polyol to increase the cohesive energy, the lamination strength can be further increased.

As the low-molecular-weight polyol, various known compounds having two or more hydroxyl groups that are commonly used for the production of polyester polyols can be used, and one or more of them may be used in combination. Specifically, for example, 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; 2-methyl-1,5-pentanediol, 3-methyl-1,5-pentanediol, 1 , 2-butanediol, 1,3-butanediol, 2-butyl-2-ethyl-1,3-propanediol, 1,2-propanediol, 2-methyl-1,3-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- Glycols having a branched structure such as ethyl-1,6-hexanediol, 3,5-heptanediol, 2-methyl-1,8-octanediol; glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol, etc. can be used.

As the polyvalent carboxylic acid or an anhydride thereof, various known polyvalent carboxylic acids generally used in the production of polyester polyols can be used, and one or more of them may be used in combination. Specifically, for example, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, fumaric acid, maleic acid, and polyanhydrides having 6 or less carbon atoms and two or more carboxyl groups such as anhydrides of these acids Aromatic dicarboxylic acids such as carboxylic acid, phthalic acid, isophthalic acid, terephthalic acid and anhydrides of these acids, aliphatic dicarboxylic acids such as pimelic acid, suberic acid, azelaic acid, sebacic acid, dimer acid, trimellitic acid and Tricarboxylic acids such as their anhydrides, benzenetetracarboxylic acid, benzenepentacarboxylic acid, benzenehexacarboxylic acid and anhydrides of these acids can be used.

Polyester polyols are polyurethane resins such as polyester polyols obtained by ring-opening polymerization of lactones such as cyclic ester compounds such as polycaprolactone, polyvalerolactone and poly(β-methyl-γ-valerolactone). Various known polyester polyols generally used in the production of may be used, or one or more of them may be used in combination.

The number average molecular weight of the polyester polyol is preferably in the range of 500 to 8,000, more preferably in the range of 800 to 7,000, even more preferably in the range of 900 to 6,000. .

As the polyether polyol, various known polyether polyols that are commonly used in the production of polyurethane resins can be used, and one or more of them may be used in combination. Examples thereof include polyether polyols of polymers or copolymers such as methylene oxide, ethylene oxide, propylene oxide and tetrahydrofuran. Specifically, known general-purpose ones such as polyethylene glycol, polypropylene glycol, and polytetramethylene glycol may be used. By containing the polyether polyol, the adhesion on the high-performance barrier film is significantly improved, resulting in excellent blocking resistance and lamination strength.

The polyether polyol preferably has a number average molecular weight of 100-3500. If the polyether polyol has a number average molecular weight of less than 100, the polyurethane resin (A) film tends to be hard and the adhesion to the polyester film is lowered. If the number average molecular weight is more than 3,500, the polyurethane resin film tends to be brittle, and the blocking resistance of the ink film is lowered.

The polyether polyol is preferably contained in the range of 1 to 40% by mass with respect to the polyurethane resin. If the polyether polyol is less than 1 part by mass with respect to 100 parts by mass of the polyurethane resin, the solubility of the polyurethane resin (A) in ketone, ester, and alcohol-based solvents is reduced, resulting in poor adhesion on the high-performance barrier film. tend to decline. In addition, the resolubility of the ink film in the solvent tends to decrease, and the tone reproducibility of the printed matter tends to decrease. On the other hand, if it exceeds 50 parts by mass, the ink film tends to be excessively soft and the anti-blocking property tends to be poor.

In addition, various known polyols that are generally used in the production of polyurethane resins can be used as combined polyols that are optionally used in polyurethane resins, and one or more of them may be used in combination. For example, ethylene glycol, 1,2-propanediol, 1,3-propanediol, 2methyl-1,3propanediol, 2ethyl-2butyl-1,3propanediol, 1,3-butanediol, 1,4 -butanediol, neopentylglycol, pentanediol, 3-methyl-1,5pentanediol, hexanediol, octanediol, 1,4-butynediol, 1,4-butylenediol, diethylene glycol, triethylene glycol, dipropylene glycol , glycerin, trimethylolpropane, trimethylolethane, 1,2,6-hexanetriol, 1,2,4-butanetriol, sorbitol, pentaerythritol, and other saturated or unsaturated low-molecular-weight polyols (1); Polycarbonate polyols (2) obtained by reacting the aforementioned low-molecular-weight polyols with, for example, dimethyl carbonate, diphenyl carbonate, ethylene carbonate, phosgene, etc.; Polybutadiene glycols (3); Addition of ethylene oxide or propylene oxide to bisphenol A; Glycols obtained by (4); one or more hydroxyethyl, hydroxypropyl acrylate, acrylic hydroxybutyl, etc. in one molecule, or their corresponding methacrylic acid derivatives, etc., and, for example, acrylic acid, methacrylic acid, or Examples include acrylic polyol (4) obtained by copolymerizing the ester thereof.

Diisocyanate compounds used in polyurethane resins include various known aromatic diisocyanates, aliphatic diisocyanates, and alicyclic diisocyanates that are generally used in the production of polyurethane 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, dimeryl diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, 1,3-bis(isocyanatomethyl)cyclohexane, methylcyclohexane diisocyanate, norbornane diisocyanate, m-tetramethylxylylene diisocyanate Examples include isocyanate, 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 combination of two or more.

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

A monovalent active hydrogen compound can also be used as a terminal blocker for the purpose of terminating the reaction. Examples of such compounds include dialkylamines such as di-n-butylamine and alcohols such as ethanol and isopropyl alcohol. Furthermore, amino acids such as glycine and L-alanine can be used as a reaction terminator, especially when it is desired to introduce a carboxyl group into the polyurethane resin. These terminal blocking agents can be used alone or in combination of two or more.

Polyurethane resins can be prepared, for example, by reacting polypropylene glycol and a polyol used in combination with a diisocyanate compound in a proportion in which the isocyanate groups are excessive to obtain a prepolymer having terminal isocyanate groups, and dissolving the resulting prepolymer in an appropriate solvent, i.e., non- Ester-based solvents such as ethyl acetate, propyl acetate, and butyl acetate, which are commonly used as solvents for toluene-based gravure ink; ketone-based solvents such as acetone, methyl ethyl ketone, and methyl isobutyl ketone; methanol, ethanol, isopropyl alcohol, n-butanol, etc. alcohol-based solvent; hydrocarbon-based solvents such as methylcyclohexane and ethylcyclohexane; or a two-step method of reacting with a chain extender and (or) a terminal blocker in a mixed solvent thereof, or polypropylene glycol and a combined polyol, It is produced by a one-step method in which a diisocyanate compound, a chain extender and/or a terminal blocker are reacted together in a suitable solvent among those mentioned above. Among these methods, the two-step method is preferable for obtaining a uniform polyurethane resin. Further, when producing a polyurethane resin by a two-step method, the total (equivalent ratio) of the amino groups of the chain extender and (or) terminal blocker is 1/0.9 to 1.3. is preferred. If the equivalent ratio of the isocyanate group to the amino group is less than 1/1.3, the chain extender and/or the terminal blocker remain unreacted, causing yellowing of the polyurethane resin and odor after printing. may occur. Furthermore, in recent years, from the viewpoint of work environment, it is more preferable not to use aromatic solvents such as toluene and xylene, and ketone solvents.

The weight average molecular weight of the polyurethane resin thus obtained is preferably within the range of 15,000 to 100,000, more preferably within the range of 15,000 to 80,000. When the weight-average molecular weight of the polyurethane resin is less than 15,000, the blocking resistance of the resulting ink composition, the strength of the printed film, the oil resistance, etc. tend to be low. , the viscosity of the resulting ink composition tends to be high and the glossiness of the printed film tends to be low.

The content of the polyurethane resin used in the liquid ink composition of the present invention in the ink (the solid content of the polyurethane resin) is 4 mass % or more, 5 mass % or more, and 6 mass % or more are preferable. On the other hand, it is preferably 25% by mass or less, preferably 20% by mass or less, and preferably 15% by mass or more from the viewpoint of appropriate ink viscosity and work efficiency during ink production and printing.

In addition, the lower limit of the solid content mass ratio in the ink is preferably 5% by mass, more preferably 10% by mass, more preferably 15% by mass, and 20% by mass. More preferably, it is still more preferably 25% by mass. The upper limit of the solid content weight ratio in the ink is preferably 95% by mass, more preferably 90% by mass, more preferably 80% by mass, and more preferably 75% by mass. Preferably, it is more preferably 70% by mass.

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

Among the above, cellulose acetate propionate, cellulose acetate butyrate, and nitrocellulose are preferable as the cellulose resin. As for the molecular weight, a weight average molecular weight of 5,000 to 200,000 is preferable, and 10,000 to 50,000 is more preferable. Further, those having a glass transition temperature of 120° C. to 180° C. are preferable. When the polyurethane resin (A) of the present invention is used in combination, it can be expected that blocking resistance, scratch resistance and other physical properties of the ink film are improved.

Nitrocellulose (nitrocellulose) is obtained as a nitric ester obtained by reacting natural cellulose with nitric acid to replace three hydroxyl groups in the 6-membered ring of the anhydride glucopyranose group in natural cellulose with nitric acid groups. preferable.

(polyvinyl butyral resin)
Dispersibility can be improved by containing a polyvinyl butyral resin as a binder resin. As the polyvinyl butyral resin (B), known ones can be used without particular limitation. In general, a reactant obtained by acetalizing polyvinyl alcohol with butyraldehyde by a known reaction can be used.

The weight average molecular weight of the polyvinyl butyral resin is preferably 5,000 to 60,000, more preferably 6,000 to 50,000, and even more preferably 7,000 to 40,000. By setting the weight average molecular weight of the polyvinyl butyral resin (B) within the above range, it is possible to obtain an ink having excellent balance between fluidity and dispersibility.

The glass transition temperature (hereinafter sometimes referred to as Tg) of the polyvinyl butyral resin is preferably in the range of 50°C to 120°C, more preferably in the range of 55°C to 115°C, more preferably in the range of 60°C to 110°C. preferable. In the present invention, the glass transition temperature is obtained by measurement with a differential scanning calorimeter.

The amount of hydroxyl groups in the polyvinyl butyral resin is preferably in the range of 10-30% by mass, more preferably 15-25% by mass. By setting the amount of hydroxyl groups in the polyvinyl butyral resin within the above range, an ink having excellent balance between fluidity and dispersibility can be obtained.

The polyvinyl butyral resin content (solid content of the polyvinyl butyral resin) is preferably 0.1 to 5% by mass, more preferably 0.1 to 4.0% by mass, based on 100% by mass of the ink. Yes, most preferably 0.2 to 3.0% by mass. Adding 0.1% by mass or more of polyvinyl butyral resin tends to maintain the adhesion and transferability of the ink film. can hold The lower limit of the solid content weight ratio in the ink is preferably 0.1% by mass, more preferably 0.2% by mass, and most preferably 0.3% by mass. Also, the upper limit of the solid content weight ratio in the ink is preferably 16% by mass, more preferably 13% by mass, and most preferably 10% by mass.

In order to stably disperse the pigment in an organic solvent, the resin alone can be dispersed, but a dispersant can also be used in combination to further stably disperse the pigment. Anionic, nonionic, cationic, and amphoteric surfactants can be used as dispersants. For example, a comb-structure polymer compound obtained by adding polyester to polyethyleneimine, or an alkylamine derivative of an α-olefin maleic acid polymer may be used. Specific examples include Solspers series (ZENECA), Ajisper series (Ajinomoto), Homogenol series (Kao), and the like. BYK series (BYK-Chemie), EFKA series (EFKA) and the like can also be used as appropriate. The dispersant is preferably contained in the ink in an amount of 0.05% by mass or more relative to the total mass of the ink from the viewpoint of ink storage stability, and 5% by mass or less from the viewpoint of lamination suitability, and more preferably 0. .1 to 2% by mass.

The liquid ink composition further contains a combined resin, extender pigment, pigment dispersant, leveling agent, antifoaming agent, wax, plasticizer, infrared absorber, ultraviolet absorber, fragrance, flame retardant, etc., if necessary. can also

(Organic solvent)
As the organic solvent used in the liquid ink composition, various organic solvents can be used. For example, aromatic organic solvents such as toluene and xylene; ester solvents such as n-propyl acetate, butyl acetate and propylene glycol monomethyl ether acetate; can be used in mixtures of In recent years, from the viewpoint of work environment, it is more preferable not to use aromatic solvents such as toluene and xylene and ketone solvents.

The liquid ink composition may contain water together with the organic solvent as a volatile component. The water content is preferably less than 10% by mass of the total amount of the ink composition. By adding water, it is possible to control the drying property of the ink, and particularly in gravure printing, it is possible to reproduce the gradation part with a small amount of ink transfer, which is a characteristic of gravure printing. Further, the range of 1 to 5% by mass based on the total amount of the ink composition is particularly preferable since printability is improved.

Also, by adding such water, it is possible to reduce the organic solvent component used. Water may be added in advance to the organic solvent to obtain a water-containing organic solvent, or a specific amount of water may be added separately.

Whether the liquid ink composition is a one-liquid type that does not use a curing agent such as an isocyanate curing agent or a two-liquid type that uses a curing agent, a liquid ink composition with excellent ink dispersibility and fluidity can be obtained.

A liquid ink composition can be produced by dissolving and/or dispersing a resin, pigment, etc. in an organic solvent. Specifically, an ink can be produced by producing a pigment dispersion by dispersing a pigment in an organic solvent using a polyurethane resin, and blending other compounds into the obtained pigment dispersion as necessary. can.

The particle size distribution of the pigment in the pigment dispersion is adjusted by appropriately adjusting the size of the grinding media of the disperser, the filling rate of the grinding media, the dispersion processing time, the ejection speed of the pigment dispersion, the viscosity of the pigment dispersion, and the like. be able to. As the dispersing machine, commonly used roller mills, ball mills, pebble mills, attritors, sand mills and the like can be used.

If the ink contains air bubbles or unexpectedly large particles, it is preferable to remove them by filtration, etc., as this will reduce the quality of the printed matter. A conventionally known filter can be used.

The viscosity of the ink produced by the above method is preferably in the range of 10 mPa·s or more from the viewpoint of preventing sedimentation of the pigment and appropriately dispersing the pigment, and in the range of 1000 mPa·s or less from the viewpoint of work efficiency during ink production and printing. preferable. The above viscosity is measured at 25° C. with a B-type viscometer manufactured by Tokimec.

The viscosity of the ink can be adjusted by appropriately selecting the types and amounts of raw materials used, such as polyurethane resins, colorants, and organic solvents. Also, the viscosity of the ink can be adjusted by adjusting the particle size and particle size distribution of the pigment in the ink.

The hues of the liquid ink composition used in the color printing layer include yellow, red, indigo, and black as process basic colors, and red (orange) and grass (grass) as process gamut external colors, depending on the type of pigment used. There are three colors: green) and purple. Further, transparent yellow, peony, vermillion, brown, gold, silver, pearl, almost transparent medium for adjusting color density (including extender pigment if necessary), etc. are prepared as base colors. The ink for boiling retort is appropriately selected in consideration of the migration property and heat resistance of the pigment. The base ink of each hue is diluted with a diluting solvent to a viscosity and density suitable for gravure printing or flexographic printing, and supplied to each printing unit singly or in combination.

<Liquid ink composition containing white pigment>
A liquid ink composition containing a white pigment contains a white pigment, a binder resin, an organic solvent, and optionally water and various additives.

Examples of white pigments include titanium oxide, zinc sulfide, lead white, zinc white, litbon, antimony white, basic lead sulfate, basic lead silicate, barium sulfate, calcium carbonate, gypsum, and silica. Among them, titanium oxide is preferable from the viewpoint of coloring power, hiding power, chemical resistance, and weather resistance, and from the viewpoint of printing performance, the titanium oxide may be treated with silica and/or alumina.

The white pigment used in the white printed layer of the present invention contains less than 200 ppm of iron element per 100 parts by mass of the white pigment. If it exceeds this range, the white printed layer tends to be yellowish and lose its whiteness. Although the cause of the yellow tint is not clear, it is presumed that the compounds containing iron components are chromatic. Therefore, it is preferable that the amount of iron element is as small as possible, and the iron element is preferably less than 150 ppm, more preferably less than 100 ppm, preferably less than 80 ppm, and less than 60 ppm per 100 parts by mass of the white pigment. is preferably less than 50 ppm, preferably less than 40 ppm, more preferably less than 30 ppm. As such a white pigment, commercially available titanium oxide can be used, and the above-mentioned coloring pigment without surface treatment with an iron compound is applicable.

The content of the white pigment depends on the desired ink performance, but for white inks that require standard opacity and high plate fogging, the content is usually about 20 to 40% by mass based on the total mass of the ink. On the other hand, in the case of white ink aiming at very high opacity as a required performance, the content may be designed at about 40 to 60% by mass.

In the liquid ink composition containing the white pigment, the components other than the white pigment, such as the binder resin, the organic solvent, and other additives, may be the same as in the liquid ink composition containing the coloring content described above. can.

(printed matter)
The printed matter of the present invention is a multi-layered printed matter in which a white printed layer and a color printed layer are laminated on a film substrate. The white printed layer and the color printed layer can be formed by printing on various film substrates using the liquid ink composition described above, and a gravure printing plate such as an electronic engraving intaglio or an erosion type intaglio is used. While it is useful as an ink for gravure printing or flexographic printing using a flexographic printing plate such as a resin plate, it excludes inks for inkjet systems in which ink is ejected from inkjet nozzles without using a plate.

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

The film substrate is, for example, polyethylene terephthalate (hereinafter sometimes referred to as PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polyester resin such as polybutylene naphthalate, nylon 6 , Polyamides such as nylon 66 and nylon 46, polyhydroxycarboxylic acids such as polylactic acid, poly (ethylene succinate), biodegradable resins such as poly (butylene succinate) and other aliphatic polyester resins, polypropylene (CPP: Non-stretched polypropylene film, OPP: biaxially stretched polypropylene film), polyolefins such as polyethylene (LLDPE: low-density polyethylene film, HDPE: high-density polyethylene film), polyimide, polyarylate, polystyrene, polyacrylonitrile, polyvinyl alcohol, ethylene-vinyl Examples include films made of thermoplastic resins such as alcohol copolymers or mixtures thereof, and laminates thereof. Among them, films made of polyester, polyamide, polyethylene, and polypropylene can be preferably used.

It is also preferable to use a film formed of a material containing a biomass-derived component as the film substrate. Biomass films are sold by various companies, and for example, sheets listed in the list of certified biomass products described by the Japan Organic Resources Association can be used.

A well-known specific film is made from biomass-derived ethylene glycol. Biomass-derived ethylene glycol is produced from biomass-derived ethanol (biomass ethanol). For example, biomass-derived ethylene glycol can be obtained by a method in which biomass ethanol is converted into ethylene glycol via ethylene oxide by a conventionally known method. Also, commercially available biomass ethylene glycol may be used, and for example, biomass ethylene glycol commercially available from India Glycol can be preferably used.

Alternatively, products that use biomass raw materials classified by the degree of biomass plastic specified by ISO16620 or ASTM D6866 are also in circulation. Radiocarbon 14C exists in the atmosphere at a rate of 1 in 1012, and this rate does not change even with carbon dioxide in the atmosphere. Therefore, the carbon of the plant-derived resin contains radioactive carbon 14C. In contrast, the carbon of the fossil fuel-derived resin contains almost no radioactive carbon 14C. Therefore, by measuring the concentration of radioactive carbon 14C in the resin with an accelerator mass spectrometer, the content ratio of the plant-derived resin in the resin, that is, the degree of biomass plasticity can be obtained. Examples of plant-derived low-density polyethylene, which is a biomass plastic having a biomass plastic degree of 80% or more, preferably 90% or more, as defined by ISO 16620 or ASTM D6866 include, for example, Braskem's product names "SBC818" and "SPB608". "SBF0323HC", "STN7006", "SEB853", "SPB681" and the like can be mentioned, and films using these as raw materials can be preferably used.

For example, as an alternative to conventional polyethylene terephthalate films using petroleum-based raw materials, films containing biomass polyester, biomass polyethylene terephthalate, etc., having biomass-derived ethylene glycol as a diol unit and fossil fuel-derived dicarboxylic acid as a dicarboxylic acid unit. It has been known.
The dicarboxylic acid unit of biomass polyester uses the dicarboxylic acid derived from a fossil fuel. As dicarboxylic acids, aromatic dicarboxylic acids, aliphatic dicarboxylic acids, and derivatives thereof can be used without limitation.

In addition to the above diol component and dicarboxylic acid component, a difunctional oxycarboxylic acid, a trifunctional or higher polyhydric alcohol for forming a crosslinked structure, a trifunctional or higher polycarboxylic acid and/or its anhydride. It may also be a copolymerized polyester in which a copolymerization component is added as a third component such as at least one polyfunctional compound selected from the group consisting of polycarboxylic acids and tri- or more functional oxycarboxylic acids.

In addition, for example, as an alternative to conventional polyolefin films using petroleum-based raw materials, biomass polyolefin films such as biomass polyethylene films containing polyethylene resins made from biomass-derived ethylene glycol, biomass polyethylene-polypropylene films, etc. Films are also known.

The polyethylene-based resin is not particularly limited except that the biomass-derived ethylene glycol is used as a part of the raw material. ethylene-α-olefin copolymer containing 90% by mass or more of units), and these can be used alone or in combination of two or more.

The α-olefin constituting the copolymer of ethylene and α-olefin is not particularly limited, and may be 1-butene, 4-methyl-1-pentene, 1-hexene, 1-octene, or the like having 4 to 10 carbon atoms. 8 α-olefins. Known polyethylene resins such as low density polyethylene resins, medium density polyethylene resins and linear low density polyethylene resins can be used.

Among them, from the viewpoint of making it even more difficult to cause damage such as holes and tears even if the films rub against each other, linear low-density polyethylene resin (LLDPE) (a copolymer of ethylene and 1-hexene, or ethylene and 1-octene) are preferred, and linear low density polyethylene resins having a density of 0.910 to 0.925 g/cm3 are more preferred.

Films and sheets containing starch, which is a biomass raw material, and polylactic acid are also known. These can be appropriately selected and used depending on the application.

The biomass film may be a laminate obtained by laminating a plurality of biomass films, or may be a laminate of a conventional petroleum-based film and a biomass film.

These petroleum-based films and biomass films are produced by laminating vapor-deposited layers of metals such as aluminum, metal oxides such as silica and alumina, using metal foils, etc., using polyvinyl alcohol, ethylene-vinyl alcohol copolymer, A barrier film containing a gas barrier layer such as vinylidene chloride may be used in combination, or may be coated with polyvinyl alcohol or the like. By using such a film, it is possible to obtain a laminate having a high barrier property against water vapor, oxygen, alcohol, inert gas, volatile organic matter (fragrance), and the like.

In addition, these films may be unstretched films or stretched films, and the manufacturing method is not limited. As a stretching treatment method, it is common to melt-extrude a resin into a sheet by an extrusion film-forming method or the like, and then subject the sheet to simultaneous biaxial stretching or sequential biaxial stretching. In the case of sequential biaxial stretching, it is common to first perform longitudinal stretching and then laterally stretching. Specifically, a method of combining longitudinal stretching using a speed difference between rolls and transverse stretching using a tenter is often used.

Also, the thickness of the base film is not particularly limited, but it is usually in the range of 1 to 500 μm. Various surface treatments such as flame treatment and corona discharge treatment may be applied to the surface of the film, if necessary, so that an adhesive layer free from defects such as film tearing and repelling is formed.

As a printing method, known printing methods such as gravure printing and flexographic printing can be used, but printing by the gravure printing method is particularly preferable.

The above printing method, that is, after the printing ink is once adhered and transferred to the printing plate or printing pattern, the ink alone is adhered to the substrate again, and if necessary, dried or cured in an oven to fix the printed matter. Obtainable. The film thickness of the printing ink formed by the gravure printing method or the flexographic printing method using the liquid printing ink of the present invention is, for example, 10 μm or less, preferably 5 μm or less.

For the printed material of the present invention, the liquid ink composition described above can be preferably used as ink for surface printing, ink for reverse printing, or ink for lamination on a film substrate. When used as an ink for surface printing, an overprint varnish layer can be provided separately. On the other hand, when it is used as an ink for reverse printing, an anchor coat varnish layer can be separately provided.

In the printed matter, the order in which the color printed layer and the white printed layer are provided is not particularly limited, and may be laminated in the order of film substrate/color printed layer/white printed layer, or film substrate/white printed layer/color printed layer. Layers may be laminated in order. For example, the color printed layer can form a pattern with a coloring agent, and the second white printed layer formed with a liquid printing ink containing a white pigment, and the third printed layer can be used as the background of the pattern. can be done.

Furthermore, it may have another printed layer, and the other printed layer may have, for example, a white pigment. may

(Laminate)
The laminate of the present invention is a laminate obtained by laminating a plurality of substrates and having a printed layer of the liquid printing ink of the present invention on at least one of the substrates. The substrates can be bonded together with an adhesive or laminated by extrusion lamination.

As a more specific structure of the laminate,
(1) Base film 1/printed layer/adhesive layer 1/sealant film (2) Base film 1/printed layer/adhesive layer 1/metal deposition unstretched film (3) Base film 1/printed layer/adhesive layer 1/metal vapor deposition stretched film (4) transparent vapor deposition stretched film/printing layer/adhesive layer 1/sealant film (5) base film 1/printing layer/adhesive layer 1/base film 2/adhesive layer 2/sealant film ( 6) Base film 1/printed layer/adhesive layer 1/metal vapor deposition stretched film/adhesive layer 2/sealant film (7) Base film 1/printed layer/adhesive layer 1/transparent vapor deposited stretched film/adhesive layer 2/sealant Film (8) Base film 1/printed layer/adhesive layer 1/metal layer/adhesive layer 2/sealant film (9) Base film 1/printed layer/adhesive layer 1/base film 2/adhesive layer 2/metal Layer/adhesive layer 3/sealant film (10) base film 1/printing layer/adhesive layer 1/metal layer/adhesive layer 2/base film 2/adhesive layer 3/sealant film and the like, but not limited thereto . The above-mentioned "base film 1/and printed layer" corresponds to the above printed matter having a white printed layer and a color printed layer on a film base. In addition, in the above configurations (1) to (10), a configuration in which a printed layer is provided on the surface of the base film 1 on the side of the adhesive layer 1 is described, but the surface (surface) of the base film 1 opposite to the adhesive layer 1 A printed layer may be provided on the substrate film 2 , or a configuration in which the printed layer is provided on the base film 2 may be employed.

Examples of the base film 1 used in configuration (1) include OPP film, PET film, nylon film (hereinafter also referred to as Ny film), and the like. Further, as the base film 1, a film coated for the purpose of improving gas barrier properties, ink receptivity when providing a printing layer described later, and the like may be used. Commercial products of the coated base film 1 include K-OPP film and K-PET film. Examples of sealant films include CPP films and LLDPE films.

Examples of the base film 1 used in configurations (2) and (3) include OPP films and PET films. A VM-CPP film obtained by vapor-depositing a metal such as aluminum on a CPP film may be used as the unstretched metal vapor-deposited film, and a VM-OPP film obtained by vapor-depositing a metal such as aluminum on an OPP film may be used as the stretched metal-deposited film. can be done.

Examples of transparent vapor-deposited stretched films used in configuration (4) include films obtained by vapor-depositing silica or alumina on OPP films, PET films, nylon films, or the like. For the purpose of protecting the inorganic deposition layer of silica or alumina, etc., a film obtained by coating the deposition layer may be used. Examples of the sealant film include those similar to those of the configuration (1).

Examples of the base film 1 used in the configuration (5) include PET film and the like. Examples of the base film 2 include a nylon film. Examples of the sealant film include those similar to those of the configuration (1).

Examples of the base film 1 of configuration (6) include the same ones as those of configurations (2) and (3). Examples of the metal-deposited oriented film include VM-OPP film and VM-PET film obtained by subjecting an OPP film or PET film to metal deposition such as aluminum. Examples of the sealant film include those similar to those of the configuration (1).

Examples of the base film 1 of configuration (7) include a PET film and the like. Examples of the transparent vapor-deposited stretched film include those similar to those of the configuration (4). Examples of the sealant film include those similar to those of the configuration (1).

Examples of the base film 1 of configuration (8) include a PET film and the like. Aluminum foil etc. are mentioned as a metal layer. Examples of the sealant film include those similar to those of the configuration (1).

Examples of the base film 1 of configurations (9) and (10) include PET films. Examples of the base film 2 include a nylon film. Aluminum foil etc. are mentioned as a metal layer. Examples of the sealant film include those similar to those of the configuration (1).
(adhesion layer)
A known adhesive for film lamination can be appropriately used for the adhesive layer. In the case of lamination by extrusion lamination, a known anchor coating agent for extrusion lamination can be appropriately used as an adhesion aid. When materials having gas barrier properties are used as these adhesives and anchor coating agents, laminates having particularly excellent barrier properties can be obtained.

Especially preferable as an adhesive with excellent gas barrier properties is that the cured coating film of the adhesive applied at 3 g/m ² (solid content) has an oxygen barrier property of 300 cc/m ² /day/atm or less, or a water vapor barrier property of 120 g/m 2 /day/atm or less. It means that it satisfies at least one condition of m ² /day or less. Examples of commercially available products include "PASLIM" series such as PASLIM VM001 and PASLIM J350X manufactured by DIC Corporation, and "Maxieve" manufactured by Mitsubishi Gas Chemical Company.

The adhesive layer can use any known material without any particular limitation, but preferably contains a cured product of a polyol and an isocyanate compound. When these polyols and/or isocyanate compounds contain biomass-derived components, a laminate having a high degree of biomass can be obtained, and the environmental load can be reduced.

In addition, adhesion promoters, acid anhydrides, compounds with oxygen scavenging functions, tackifiers, gas barrier adhesives, stabilizers (antioxidants, heat stabilizers, UV absorbers, etc.), plasticizers, antistatic agents, A lubricant, an antiblocking agent, a coloring agent, a crystal nucleating agent, etc. may be contained. These various additives may be added in advance to either one or both of the polyol composition (A) and the polyisocyanate composition (B), or may be added to the polyol composition (A) and the polyisocyanate composition ( B) may be added when mixing.

The gas barrier adhesive to be used may be either solvent type or non-solvent type. When the gas barrier adhesive to be used is a solvent type, the adhesive of the present invention is applied onto the printed layer surface printed on the first substrate using a roll such as a gravure roll, and heated in an oven or the like. After evaporating the organic solvent, the other substrate is attached to obtain the laminate of the present invention. It is preferable to perform an aging treatment after lamination. The aging temperature is preferably room temperature to 80° C., and the aging time is preferably 12 to 240 hours.

When the gas barrier adhesive to be used is a non-solvent type, the adhesive of the present invention preheated to about 40° C. to 100° C. is applied onto the surface of the printed layer printed on the first substrate by a gravure roll or the like. After the application using the roll of No. 2, the other substrate is immediately laminated to obtain the laminate of the present invention. It is preferable to perform an aging treatment after lamination. The aging temperature is preferably room temperature to 70° C., and the aging time is preferably 6 to 240 hours.

When the gas barrier adhesive to be used is used as an adhesion aid, the adhesion aid of the present invention is applied onto the surface of the printed layer printed on the first base material using a roll such as a gravure roll, and then dried in an oven or the like. After volatilizing the organic solvent by heating, the laminate of the present invention is obtained by laminating the polymer material melted by an extruder. Polyolefin-based resins such as low-density polyethylene resin, linear low-density polyethylene resin, and ethylene-vinyl acetate copolymer resin are preferable as the polymer material to be melted. The aging temperature is preferably room temperature to 70° C., and the aging time is preferably 6 to 240 hours.

The coating amount of the gas barrier adhesive to be used is appropriately adjusted. In the case of a solvent-based adhesive, for example, the solid content is adjusted to 1 g/m ² or more and 10 g/m ² or less, preferably 2 g/m 2 ^or more and 5 g/m ² or less. In the case of a solventless adhesive, the coating amount of the adhesive is, for example, 1 g/m ² or more and 5 g/m ² or less, preferably 1 g/m ^{2 or} more and 3 g/m ² or less.

When an adhesive is used as an adhesion adjuvant, the coating amount is appropriately adjusted, and is, for example, 0.03 g/m ² or more and 2 g/m ² or less (solid content).

(Laminate other layer)
The laminate of the present invention may be used alone or may further contain other films or substrates. As other substrates, in addition to the stretched film, unstretched film, and transparent vapor-deposited film described above, porous substrates such as paper, wood, and leather can also be used. The adhesive used when bonding other substrates may or may not be a gas barrier adhesive as described above.

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

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

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

EXAMPLES The present invention will be described more specifically with reference to Examples. Hereinafter, "parts" and "%" are based on mass.
In addition, the measurement of the weight average molecular weight (in terms of polystyrene) by GPC (gel permeation chromatography) in the present invention was carried out under the following conditions using an HLC8220 system manufactured by Tosoh Corporation.
Separation column: 4 TSKgelGMHHR-N manufactured by Tosoh Corporation are used. Column temperature: 40°C. Moving bed: Tetrahydrofuran manufactured by Wako Pure Chemical Industries, Ltd. Flow rate: 1.0 ml/min. Sample concentration: 1.0% by weight. Sample injection volume: 100 microliters. Detector: differential refractometer.
Viscosity was measured at 25° C. with a B-type viscometer manufactured by Tokimec.

In this example, the amount of iron element contained in the pigment was measured using an energy dispersive X-ray fluorescent spectrometer, PANalytical Epsilon 5 (manufactured by Spectris Co., Ltd.).

In this example, the amount of base adsorption per surface area of the pigment was measured by the following method.
About 100 mg of the pigment was weighed into a 50 mL polyethylene wide-mouthed bottle together with 15 mL of the base solution for adsorption, and mixed and stirred with a paint shaker (manufactured by Toyo Seiki Seisakusho Co., Ltd.) (750 cpm, 15 minutes).
Subsequently, the pigment was sedimented by centrifugation (3500 G, 20 minutes) using a cooling high-speed centrifuge H-2000B (manufactured by Kokusan Co., Ltd.), and then 10 mL of the supernatant was collected.
This is diluted with n-propyl acetate (manufactured by Kanto Chemical Co., Ltd.) 15 mL, and an automatic titrator COM-A19 (manufactured by HIRANUMA Co., Ltd.) is subjected to potentiometric titration with an acid solution for titration. The amount of adsorbed base was measured.
By subtracting the determined unadsorbed base amount from the added base amount, the base adsorption amount per pigment weight was calculated.
Then, the base adsorption amount per surface area of the pigment was calculated by dividing the base adsorption amount per weight by the nitrogen adsorption specific surface area.
As the base solution for adsorption, 0.1 mol/L tetra-n-butylammonium hydroxide solution (N/10) (benzene/methanol solution) (manufactured by Kanto Kagaku Co., Ltd.), whose factor value is known, was mixed with acetic acid. It was prepared by diluting with n-propyl (manufactured by Kanto Kagaku 20 Co., Ltd.) to exactly 1/100.
Further, as an acid solution for titration, about 95 mg of p-toluenesulfonic acid monohydrate (manufactured by Kanto Chemical Co., Ltd.) is dissolved in 500 mL of n-propyl acetate (manufactured by Kanto Chemical Co., Ltd.), and the above-mentioned adsorption base is dissolved. The solution was used after titration of concentration.

(Adjustment 1: [copper phthalocyanine pigment (PB15: 3-1)])
C. I. Pigment Blue 15:3 (manufactured by DIC Corporation) Wet cake 373.1 parts (pigment content 150 parts) and ion-exchanged water 500 parts are placed in a 2 L stainless steel cup, and the rotation speed is 500 rpm Homo Disper 2.5 type (Primix Co., Ltd.) company) for 15 minutes. C. I. Pigment Blue 15:3 slurry is transferred to a 5 L stainless steel cup, 2127 parts of ion-exchanged water is added, and iron (II) sulfate heptahydrate (Fujifilm Wako Pure Yaku Co., Ltd.) was added and dissolved, and the temperature was raised to 60°C. Subsequently, 54 parts of 35% hydrogen peroxide solution (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was added and stirred for 2 hours. Next, the slurry was subjected to Nutsche filtration, washed with 12 L of hot water at 70° C., and then dried with a constant temperature blow dryer WFO-500 (manufactured by Tokyo Rikakikai Co., Ltd.) (98° C., 18 hours). The resulting pigment mass was pulverized to obtain 150 parts of copper phthalocyanine pigment (PB15:3-1). The amount of iron element contained in the pigment was 3530 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.57 μmol/m ² .

(Comparative adjustment 1: [copper phthalocyanine pigment (PB15: 3-2)])
C. I. Pigment Blue 15:3 (manufactured by DIC Corporation) Wet cake 373.1 parts (pigment content 150 parts) and ion-exchanged water 500 parts are placed in a 2 L stainless steel cup, and the rotation speed is 500 rpm Homo Disper 2.5 type (Primix Co., Ltd.) company) for 15 minutes. C. I. Pigment Blue 15:3 slurry was transferred to a 5 L stainless steel cup, 2127 parts of ion-exchanged water was added, stirred with a stainless steel anchor blade rotating at 150 rpm, heated to 60° C. and stirred for 2 hours. Then C.I. I. Pigment Blue 15:3 slurry is filtered by Nutsche, washed with 12 L of hot water at 70 ° C., and the filter cake is dried in a constant temperature blow dryer WFO-500 (manufactured by Tokyo Rikaki Co., Ltd.) (98 ° C., 18 hours). bottom. The resulting pigment mass was pulverized to obtain 150 parts of copper phthalocyanine pigment (PB15:3-2). The amount of iron element contained in the pigment was 155 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.0 μmol/m ² .

(Adjustment 2-1: [azo pigment (PR57: 1-1)])
After dispersing 38.5 parts of 2-amino-5-methylbenzenesulfonic acid in 500 parts of water, 25.0 parts of 35% hydrochloric acid was added, and 36.8 parts of 40% aqueous sodium nitrite solution was added dropwise while maintaining the temperature at 0°C. , to obtain a diazo solution. Next, 42.5 parts of 2-hydroxy-3-naphthoic acid was dispersed in 200 parts of hot water at 50° C., and 74 parts of a 25% aqueous solution of caustic soda was added to obtain a coupler solution. After cooling the coupler solution to 10° C., the above diazo solution was added dropwise while stirring. The coupling reaction was terminated by stirring at 10° C. for 60 minutes to obtain a dye suspension. Subsequently, 77 parts of a 10% Na salt solution of gum rosin (7.7 parts as gum rosin) were added to the resulting dye suspension. After stirring for 30 minutes, a liquid prepared by dissolving 37.4 parts of 72% calcium chloride in 40 parts of water was added, and the mixture was stirred for 60 minutes to complete lake formation. After completion of the lake-forming reaction, the mixture was stirred while being heated at 25° C. for 90 minutes to obtain an aqueous suspension of a calcium lake diazo pigment (C.I. Pigment Red 57:1). This suspension was heated to 85° C., stirred for 90 minutes, filtered, washed with water, and subjected to C.I. I. A wet cake of Pigment Red 57:1 was obtained. The wet cake is added to 2500 parts of water and stirred for 1 hour. Then add 12.0 parts of iron (II) sulfate heptahydrate, stir for 30 minutes, add 37.5 parts of 35% hydrogen peroxide, and stir for an additional 2 hours. The pH of the reaction solution was adjusted to 8.0 with a 25% aqueous solution of caustic soda, 120 parts of 35% aqueous calcium chloride solution was added, and the mixture was stirred for 30 minutes, filtered, washed with water, dried at 110°C for a whole day and night, and pulverized. I. PR57:1-1, consisting of Pigment Red 57:1, was obtained. The amount of elemental iron contained in PR57:1-1 was 13780 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.80 μmol/m ² .

(Adjustment 2-2: [azo pigment (PR57: 1-2)])
After dispersing 38.5 parts of 2-amino-5-methylbenzenesulfonic acid in 500 parts of water, 25.0 parts of 35% hydrochloric acid was added, and 36.8 parts of 40% aqueous sodium nitrite solution was added dropwise while maintaining the temperature at 0°C. , to obtain a diazo solution. Next, 42.5 parts of 2-hydroxy-3-naphthoic acid was dispersed in 200 parts of hot water at 50° C., and 74 parts of a 25% aqueous solution of caustic soda was added to obtain a coupler solution. After cooling the coupler solution to 10° C., the above diazo solution was added dropwise while stirring. The coupling reaction was terminated by stirring at 10° C. for 60 minutes to obtain a dye suspension. Subsequently, 77 parts of a 10% Na salt solution of gum rosin (7.7 parts as gum rosin) were added to the resulting dye suspension. After stirring for 30 minutes, a solution obtained by dissolving 37.4 parts of 72% calcium chloride in 40 parts of water and 6.0 parts of iron (II) sulfate heptahydrate were added, and the mixture was stirred for 60 minutes to complete lake formation. . After completion of the lake-forming reaction, the mixture was stirred while being heated at 25° C. for 90 minutes to obtain an aqueous suspension of a calcium lake diazo pigment (C.I. Pigment Red 57:1). After heating this suspension to 85° C., 37.5 parts of 35% hydrogen peroxide was added, stirred for 90 minutes, filtered and washed with water. I. A wet cake of Pigment Red 57:1 was obtained. After drying the wet cake at 110° C. for a whole day and night, it was pulverized to give C.I. I. PR57:1-2 consisting of Pigment Red 57:1 was obtained. The amount of elemental iron contained in PR57:1-2 was 630 ppm. Also, the amount of base adsorption per surface area of the pigment was 1.14 μmol/m ² .

(Comparative adjustment 2) [azo pigment PR57: 1-3]
After dispersing 38.5 parts of 2-amino-5-methylbenzenesulfonic acid in 500 parts of water, 25.0 parts of 35% hydrochloric acid was added, and 36.8 parts of 40% aqueous sodium nitrite solution was added dropwise while maintaining the temperature at 0°C. , to obtain a diazo solution. Next, 42.5 parts of 2-hydroxy-3-naphthoic acid was dispersed in 200 parts of hot water at 50° C., and 74 parts of a 25% aqueous solution of caustic soda was added to obtain a coupler solution. After cooling the coupler solution to 10° C., the above diazo solution was added dropwise while stirring. The coupling reaction was terminated by stirring at 10° C. for 60 minutes to obtain a dye suspension. Subsequently, 77 parts of a 10% Na salt solution of gum rosin (7.7 parts as gum rosin) were added to the resulting dye suspension. After stirring for 30 minutes, a liquid prepared by dissolving 37.4 parts of 72% calcium chloride in 40 parts of water was added, and the mixture was stirred for 60 minutes to complete lake formation. After completion of the lake-forming reaction, the mixture was stirred while being heated at 25° C. for 90 minutes to obtain an aqueous suspension of a calcium lake diazo pigment (C.I. Pigment Red 57:1). This suspension was heated to 85° C., stirred for 90 minutes, filtered, washed with water, and subjected to C.I. I. A wet cake of Pigment Red 57:1 was obtained. After drying the wet cake at 110° C. for a whole day and night, it was pulverized to give C.I. I. A comparative PR57:1-3 consisting of Pigment Red 57:1 was obtained. The amount of elemental iron contained in PR57:1-3 was 18 ppm. Also, the amount of base adsorption per surface area of the pigment was 1.17 μmol/m ² .

(Adjustment 3: [azo pigment (PR146-1)])
After adding 12.5 parts of N-(4-chloro-2,5 dimethoxyphenyl)-3-hydroxy-2-naphthamide to 200 parts of hot water at 50° C., 0.6 parts of funnel oil and 16 parts of 25% aqueous sodium hydroxide solution. parts were added to obtain a coupler solution. Next, after dispersing 8.0 parts of 3-amino-4-methoxybenzanilide in 100 parts of water, 10 parts of 35% hydrochloric acid was added, and 6 parts of a 40% aqueous sodium nitrite solution was added dropwise while maintaining the temperature at 0°C. A solution was obtained. After adding the coupler solution to this diazo solution, the mixture was heated to 85° C., stirred for 60 minutes, filtered and washed with water. I. A wet cake of Pigment Red 146 was obtained. The wet cake is added to 500 parts of water and stirred for 1 hour. Next, add 0.58 parts of iron (II) sulfate heptahydrate, stir for 30 minutes, add 18.0 parts of 35% hydrogen peroxide, stir for an additional 2 hours, filter, wash with water, and keep at 110°C overnight. Dry and grind to obtain C.I. I. PR146-1, consisting of Pigment Red 146, was obtained. The amount of elemental iron contained in PR146-1 was 5900 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.79 μmol/m ² .

(Comparative adjustment 3: [azo pigment (PR146-2)])
After adding 12.5 parts of N-(4-chloro-2,5 dimethoxyphenyl)-3-hydroxy-2-naphthamide to 200 parts of hot water at 50° C., 0.6 parts of funnel oil and 16 parts of 25% aqueous sodium hydroxide solution. parts were added to obtain a coupler solution. Next, after dispersing 8.0 parts of 3-amino-4-methoxybenzanilide in 100 parts of water, 10 parts of 35% hydrochloric acid was added, and 6 parts of a 40% aqueous sodium nitrite solution was added dropwise while maintaining the temperature at 0°C. A solution was obtained. After adding the coupler solution to this diazo solution, the mixture was heated to 85° C., stirred for 60 minutes, filtered and washed with water. I. A wet cake of Pigment Red 146 was obtained. After drying the wet cake at 110° C. for a whole day and night, it was pulverized to give C.I. I. A comparative PR146-2 consisting of Pigment Red 146 was obtained. The amount of elemental iron contained in comparative PR146-2 was 61 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.10 μmol/m ² .

(Adjustment 4: [dioxazine pigment (PV23-1)])
C. I. Pigment Violet 23 (manufactured by DIC Corporation) 143 parts of wet cake (50 parts of pigment content) and 857 parts of ion-exchanged water are placed in a 2 L stainless steel cup, and homodisper 2.5 type (manufactured by Primix Corporation) at a rotation speed of 500 rpm. for 30 minutes. C. I. The slurry of Pigment Violet 23 was transferred to a 5 L stainless steel cup, and while stirring with a stainless steel anchor blade rotating at 150 rpm, 0.57 parts of iron (II) sulfate heptahydrate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was added. It was added and dissolved, and the temperature was raised to 60°C. Subsequently, 12.5 parts of 35% hydrogen peroxide solution (manufactured by FUJIFILM Wako Pure Chemical Industries, Ltd.) was added, and after stirring for 1 hour, 0.57 parts of iron (II) sulfate heptahydrate was additionally added, Stirred for an additional hour. Next, the slurry was subjected to Nutsche filtration, washed with 12 L of hot water at 70° C., and then dried with a constant temperature blow dryer WFO-500 (manufactured by Tokyo Rikakikai Co., Ltd.) (98° C., 18 hours). The resulting pigment mass was pulverized to obtain 50 parts of a dioxazine pigment (PV23-1).
The amount of iron element contained in the pigment was 240 ppm. Also, the amount of base adsorption per surface area of the pigment was 1.06 μmol/m ² .

(Adjustment 5: [carbon black (CB-1)])
150 parts of carbon black-A (particle size 47 nm, DBP oil absorption 47 cm 3 /100 g, nitrogen adsorption specific surface area 48 m 2 /g, pH 3.1) is added to 500 parts of water and stirred for 1 hour to wet the carbon black with water. Next, 2350 parts of water are added, and after stirring for 1 hour, 6.84 parts of iron (II) sulfate heptahydrate are added and further stirred for 30 minutes. 214.3 parts of 35% hydrogen peroxide was added thereto and stirred for 1 hour, and 1.71 parts of iron (II) sulfate heptahydrate was added and stirred for 1 hour. Subsequently, the carbon black slurry was filtered, washed with water, dried overnight at 98° C. and pulverized to obtain carbon black-1 (CB-1). The amount of elemental iron contained in CB-1 was 8590 ppm (0.8590%). The amount of base adsorption per surface area of the pigment was 0.69 μmol/m ² .

(Comparative adjustment 5: [carbon black (CB-2)])
150 parts of carbon black-A are added to 500 parts of water and stirred for 1 hour to wet the carbon black with water. Next, 2350 parts of water was added and stirred for 3 hours. Subsequently, the carbon black slurry was filtered, washed with water, dried overnight at 98° C. and pulverized to obtain carbon black (CB-2). The amount of elemental iron contained in CB-2 was 4 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.38 μmol/m ² .

(Adjustment 6: Titanium oxide (W6-1))
150 parts of titanium oxide JR-780 (manufactured by Tayka Co., Ltd.) is added to 3000 parts of water and stirred for 1 hour to wet the titanium oxide with water. Next, add 3.0 parts of iron (II) sulfate heptahydrate and stir for an additional 30 minutes. 214.3 parts of 35% hydrogen peroxide was added thereto and stirred for 1 hour, and 3.0 parts of iron (II) sulfate heptahydrate was added and stirred for 1 hour. Subsequently, the titanium oxide slurry was filtered, washed with water, dried overnight at 98° C. and pulverized to obtain titanium oxide-1 (W6-1). The amount of iron element contained in titanium oxide W6-1 was 6240 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.41 μmol/m ² .

(Synthesis Example 1) Production method of polyurethane resin solution P-1 84.5 parts of neopentyl glycol adipate diol (hydroxyl value: 56) was added to a four-necked flask equipped with a stirrer, thermometer, reflux condenser and nitrogen gas inlet tube. .6 mg KOH/g), 15.5 parts of polyethylene glycol (hydroxyl value: 278 mg KOH/g) and 27.55 parts of isophorone diisocyanate were charged and reacted at 90° C. for 10 hours under a nitrogen stream until the isocyanate group content was 2.84 weight. % urethane prepolymer was prepared, 68.7 parts of ethyl acetate was added thereto to obtain a uniform solution of urethane prepolymer. Next, the urethane prepolymer solution was added to a mixture of 7.83 parts of isophoronediamine, 0.11 parts of di-n-butylamine, 136.8 parts of ethyl acetate and 110.7 parts of isopropyl alcohol, and the mixture was heated at 45°C for 5 hours. After reacting with stirring for hours, a polyurethane resin solution P-1 was obtained.

The resulting polyurethane resin solution P-1 had a resin solid content concentration of 30.4% by weight and a resin solid content Mw of 54,000. 11.4% by weight of polyethylene glycol (15.5 parts) is contained as polyether polyol in polyurethane resin (137.76 parts in total).

(Adjustment of cellulose acetate propionate resin solution Ca)
To 20 parts of cellulose acetate propionate CAP482-0.5 (manufactured by Eastman Chemical Co.), a mixture of isopropyl alcohol/ethyl acetate/n-propyl acetate/methylcyclohexane (ratio by weight: 25/25/13/10) was added. 80 parts were added and sufficiently mixed to prepare a cellulose ester resin solution Ca having a resin solid content concentration of 20% by mass.

(Adjustment of maleic acid resin solution M)
"SMA 3000P" manufactured by Tomoe Kogyo Co., Ltd. was mixed with 25% IPA, 25% ethyl acetate, and 50% SMA 3000P and thoroughly stirred as a 50% solids solution to prepare a maleic acid resin solution M.
(Adjustment of vinyl chloride vinyl acetate copolymer resin solution)
A 10% solution of vinyl chloride-vinyl acetate copolymer resin having a hydroxyl group (vinyl chloride/vinyl acetate/vinyl alcohol = 92/3/5, hydroxyl value (mgKOH) = 64 in terms of weight percent resin monomer composition) was prepared with ethyl acetate, This was designated as vinyl chloride acetate resin solution V.

(Example 1) Liquid ink composition containing white pigment 30 parts of polyurethane resin solution P1 (solid content: 30%), 1 part of maleic acid resin solution M (solid content: 50%), cellulose acetate propionate resin solution Ca (solid content: 20%), 36 parts of titanium oxide JR-780 (manufactured by Tayka Co., Ltd.), and 30 parts of ethyl acetate, totaling 100 parts, was added to a mixture of Dyno Mill (manufactured by Willie E. Baccophenon). and kneaded to prepare a liquid ink. The titanium oxide used in Example 1 was not treated to introduce iron onto the surface of the pigment, and iron was not detected. Also, the amount of base adsorption per surface area of the pigment was 0.0 μmol/m ² .

(Examples 2 and 3 and Comparative Examples 1 and 2)
For Examples 2 and 3 and Comparative Examples 1 and 2, liquid inks were produced in the same procedure as in Example 1 with the formulations shown in Tables 1-1. The titanium oxide used in Example 2 was not treated to introduce iron onto the surface of the pigment, and the amount of elemental iron contained in the titanium oxide of Example 2 was 25 ppm. Also, the amount of base adsorption per surface area of the pigment was 0.0 μmol/m ² .
The obtained liquid ink was evaluated by the following test methods.

<Pigment Dispersibility>
(Millbase fluidity after kneading)
The viscosities of the inks described in Examples and Comparative Examples were measured with a Brookfield viscometer at rotation speeds of 6 rpm and 60 rpm. The TI value was obtained by dividing the viscosity measured at 6 rpm by the viscosity measured at 60 rpm. If the TI value is less than 3.0, it can be used practically.
○: TI value is less than 1.5 △: TI value is 1.5 or more to less than 3.0 ×: TI value is 3.0 or more (dispersion stability)
After allowing the inks described in Examples and Comparative Examples to stand at 25° C. for one week, the degree of separation and sedimentation was evaluated.

<Separation> Appearance evaluation ◯: No separation is observed.
Δ: Separation is observed in the slightly upper layer. As a guideline, the thickness of the separation layer should be 5 mm or less.
x: Clear separation is observed in the upper layer. As a guideline, the thickness of the separation layer should be 5 mm or more.
<Precipitation> Slowly scrape the bottom of the container in which the ink is stored with a spatula.
◯: No precipitation is observed.
Δ: Slight sedimentation is observed at the bottom. (A slight amount of sediment can be seen on the tip of the spatula.)
x: A lot of sediments are observed at the bottom. (A lot of the sediment can be scraped off with a spatula.)
<Evaluation of yellowness>
(Observation of hue by visual observation)
The inks described in Examples and Comparative Examples were applied to an OPP film using a bar coater #4 (RDS), and the hue was visually determined. P2161 (20 μm) manufactured by Toyobo Co., Ltd. was used as the OPP film, and the hue of each example and comparative example was evaluated relative to the hue of Example 1.
◯: It has a hue equivalent to that of Example 1.
Δ: More yellowish than in Example 1 and slightly inferior in hue.
x: More yellowish than in Example 1 and significantly inferior in hue.

From Table 1, it was found that Comparative Examples 1 and 2 using titanium oxide of adjustment 6, which was treated to introduce iron into the surface of the pigment, were tinged with yellow and affected the color. On the other hand, the experimental collars 1 to 3 using untreated titanium oxide were not affected by yellowing and were excellent in pigment dispersibility and dispersion stability.

(Example 4) Liquid ink composition containing color pigment 40 parts of polyurethane resin solution P1 (solid content: 30%), 1 part of maleic acid resin solution M (solid content: 50%), cellulose acetate propionate resin solution Ca (solid content: 20%), 10 parts of the copper phthalocyanine pigment (PB 15:3) obtained in Preparation 1, and 46 parts of ethyl acetate (a total of 100 parts) was added to a Dyno Mill (manufactured by Willie & E. Bacchofenon Co., Ltd.). was kneaded using to prepare a liquid ink.

(Examples 5-9 and Comparative Examples 3-6)
For Examples 5 to 9 and Comparative Examples 3 to 6, liquid inks were produced in the same manner as in Example 4 with the formulations shown in Tables 2 and 3.

For the obtained liquid ink, the pigment dispersibility (millbase fluidity and storage stability after kneading) was evaluated by the same evaluation method as in Example 1 above.

The viscosities of the liquid inks of Examples 4 to 9 and Comparative Examples 3 to 6 were adjusted to 16 seconds (25°C) with Zahn cup #3 (manufactured by Rigosha) with ethyl acetate, and gravure proofing was performed using a gravure plate with a plate depth of 35 µm. Using a machine, the printed material provided with the printed layer of the liquid ink of Example 1 (printed material prepared for evaluation of yellowness) was formed, and a color printed layer was formed on the white printed layer to produce a printed material. In addition, the printed material was configured to have a portion where the color printed layer was provided on the white printed layer and a portion where the color printed layer was not provided (a portion where only the white printed layer was provided).

(Adhesion)
The viscosity of the inks described in Examples and Comparative Examples was adjusted to 16 seconds (25°C) with a Zahn cup #3 (manufactured by Rigosha) with ethyl acetate, and OPP, Printed matter made from various films such as PET, NY, and transparent deposition film was left for a day, then cellophane tape (12 mm width made by Nichiban) was attached to the printed surface, and the appearance of the printed film was observed when the adhesive tape was quickly peeled off. Visual judgment was made in the following three stages.

The OPP film is P2161 (20 μm) manufactured by Toyobo Co., Ltd., the PET film is E5100 (12 μm) manufactured by Toyobo Co., Ltd., and the NY film is ON-RT (15 μm) manufactured by Unitika Ltd. Alumina-evaporated transparent PET film IB-PET-PUB (12 μm) manufactured by Dai Nippon Printing Co., Ltd. was used as the transparent vapor-deposited film.

◯: The printed film was not peeled off at all.
Δ: 50 to 80% of the printed film remained on the film.
x: 50% or less of the printed film remained on the film.
Results are shown in the table below.

From Tables 2 and 3, Examples 4 to 9 gave excellent results in all evaluations of fluidity, storage stability, and adhesion. Examples 4 to 9, in which the pigment surface was treated to introduce iron elements, exhibited excellent fluidity and dispersion stability even in ink compositions containing no vinyl chloride vinyl acetate copolymer resin.

On the other hand, from Comparative Examples 3 to 6, when a pigment whose surface is not treated with iron element is used, when the ink composition does not contain vinyl chloride vinyl acetate copolymer resin, fluidity and dispersion stability are improved. It was found that the performance of the ink composition not using the chlorine-based resin was inferior due to environmental and human safety concerns. Also in the printed matter of Comparative Examples 3 to 6, the yellowness of the white printed layer (the portion where the color printed layer was not provided) had an effect, and the color of the printed matter changed.

Claims

A multilayer printed matter in which a white printed layer having a white pigment and at least one color printed layer having a pigment other than a white pigment are laminated on a film substrate,
The at least one pigment other than the white pigment contains 200 ppm or more of iron element per 100 parts by mass of the pigment,
The printed matter, wherein the white pigment contains less than 200 ppm of iron element per 100 parts by mass of the white pigment.
The printed matter according to claim 1, wherein the white pigment is titanium oxide.
3. The printed matter according to claim 1, wherein the pigment other than the white pigment has a base adsorption amount per surface area of the pigment of 0.30 μmol/m 2 or more.
3. The printed matter according to claim 1 or 2, wherein the color printing layer contains at least one resin selected from polyurethane resin, maleic acid resin, cellulose resin, polyester resin, acrylic resin, polyamide resin, and polyvinyl butyral resin. .
The printed matter according to claim 1 or 2, wherein the color printed layer does not contain a chlorine-based resin.
The printed matter according to claim 1 or 2, wherein the white printed layer does not contain a chlorine-based resin.
A laminated laminate having the printed matter according to claim 1 or 2.