JP7131174B2 - IMAGE FORMING METHOD, IMAGE FORMING APPARATUS, AND PRINTED MATERIAL MANUFACTURING METHOD - Google Patents

Description

The present invention relates to an image forming method, an image forming apparatus, and a method for manufacturing printed matter.

Inkjet printers have advantages such as low noise, low running costs, and easy color printing, and are widely used in general households as digital signal output devices. In recent years, there have been developments in techniques for forming images by inkjet on packaging materials for food, beverages, daily necessities, and the like, as well as for household use.

In Japan, non-absorbent printed materials such as plastic films (also called non-permeable substrates, non-absorbent recording media, etc.) are used as printed materials to which inkjet is applied, and inks for this purpose have been developed. ing. An example of the need for direct inkjet printing on such plastic films is packaging printing for food and daily necessities. Image quality is required.

However, when ink-jet printing is performed on a non-absorbent substrate, penetration drying does not occur, so the ink droplets spread excessively, and white characters (also called negative characters) may be crushed and illegible. .

In order to deal with such problems, a technique is known in which a reaction liquid containing a coagulant and an ink containing a coloring material are applied in this order to a non-absorbent recording medium (see Patent Document 1).
In addition, as is known in Patent Document 2, most of such packaging applications are printed with color ink on the back surface of the plastic film, and after printing with white ink to improve the concealability and color development of the color ink, Generally, a packaging material is obtained by coating an adhesive on a printed layer and pasting a heat-sealable film to laminate. In particular, the use of polypropylene (OPP), polyethylene terephthalate (PET), and nylon (ONY) is large in flexible packaging applications. In particular, polypropylene is used most frequently because it is inexpensive and has many excellent properties such as moldability, chemical resistance, and heat resistance.

However, since polypropylene is a non-polar and crystalline resin, water-based ink is easily repelled, making it difficult to adhere the ink layer. There is a problem that it is difficult to obtain a high-quality image. Furthermore, when a plurality of color inks are used, there is a problem that bleeding occurs at color boundaries, making it impossible to obtain high-quality images.

SUMMARY OF THE INVENTION An object of the present invention is to provide an image forming method which is excellent in adhesion to impermeable substrates, suppresses bleeding, and can form high-quality images.

In order to solve the above problems, the image forming method of the present invention is an image forming method for forming an image on a resin film, wherein a surface treatment composition containing water, an organic solvent, urethane resin particles and a flocculant is used. After the step of applying onto the resin film and the step of applying the surface treatment composition onto the resin film, a non-white ink containing water, an organic solvent, acrylic resin particles and a colorant other than white is applied. and, after the step of applying the non-white ink, applying a white ink containing water, an organic solvent, acrylic resin particles, and a white colorant , wherein the urethane resin particles are polyester urethane resin particles, polyether urethane resin particles, and polycarbonate urethane resin particles .

ADVANTAGE OF THE INVENTION According to this invention, the image forming method which is excellent in the adhesiveness to an impermeable base material, suppresses bleeding, and can form a high quality image can be provided.

It is a perspective explanatory view in an example of a recording device. FIG. 4 is a perspective explanatory view of an example of a main tank; FIG. 3 is a cross-sectional explanatory diagram of an example of a printed matter;

Hereinafter, an image forming method, an image forming apparatus, and a printed matter manufacturing method according to the present invention will be described with reference to the drawings. In addition, the present invention is not limited to the embodiments shown below, and can be changed within the scope of those skilled in the art, such as other embodiments, additions, modifications, deletions, etc. is also included in the scope of the present invention as long as the functions and effects of the present invention are exhibited.

The image forming method of the present invention is an image forming method for forming an image on a non-permeable substrate, wherein a surface treatment composition containing water, an organic solvent and urethane resin particles is applied onto the non-permeable substrate. applying a non-white ink containing water, an organic solvent and acrylic resin particles; and applying a white ink containing water, an organic solvent, acrylic resin particles and a white colorant. characterized by Details will be described below.

(Surface treatment composition)
The surface treatment composition contains water, an organic solvent and urethane resin particles, and may contain other components as necessary.

<Urethane resin particles>
By including the urethane resin particles in the surface treatment composition, it is possible to obtain high adhesion to the impermeable substrate. The type of urethane resin particles contained in the surface treatment composition is not particularly limited, and can be appropriately selected according to the purpose. Moreover, it is possible to obtain a composition for surface treatment by mixing resin particles with a material such as an organic solvent in a resin emulsion state in which water is used as a dispersion medium.

The glass transition temperature Tg of the urethane resin particles in the surface treatment composition is preferably −25 to 75° C., more preferably −25 to 25° C., more preferably −25 to 10° C. from the viewpoint of improving adhesion. is more preferable. The Tg of the urethane resin particles can be measured by DSC (Thermo plus EVO2/DSC manufactured by Rigaku Corporation).

The content of the urethane resin particles is preferably 0.5% by mass or more and 20% by mass or less as a solid content with respect to the total amount of the composition for surface treatment. When the resin content is 0.5% by mass or more, the base material can be sufficiently coated with the resin, resulting in improved adhesion.

The volume average particle diameter of the urethane resin particles is not particularly limited and can be appropriately selected according to the purpose. It is more preferably 10 nm or more and 200 nm or less, and particularly preferably 10 nm or more and 100 nm or less. The volume average particle diameter can be measured, for example, using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

<Organic solvent>
The organic solvent used in the present invention is not particularly limited, and any water-soluble organic solvent can be used. Examples thereof include polyhydric alcohols, ethers such as polyhydric alcohol alkyl ethers and polyhydric alcohol aryl ethers, nitrogen-containing heterocyclic compounds, amides, amines, and sulfur-containing compounds.
Specific examples of water-soluble organic solvents include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 1,4-butane. Diol, 2,3-butanediol, 3-methyl-1,3-butanediol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,2-pentanediol, 1,3-pentanediol, 1,4-pentanediol , 2,4-pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,3-hexanediol, 2,5-hexanediol, 1,5-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl-1,2,4-butanetriol, 1,2,3-butanetriol, 2,2,4-trimethyl- Polyhydric alcohols such as 1,3-pentanediol and petriol, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl Polyhydric alcohol alkyl ethers such as ethers, polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether and ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone , 1,3-dimethyl-2-imidazolidinone, ε-caprolactam, nitrogen-containing heterocyclic compounds such as γ-butyrolactone, formamide, N-methylformamide, N,N-dimethylformamide, 3-methoxy-N,N- Amides such as dimethylpropionamide and 3-butoxy-N,N-dimethylpropionamide, amines such as monoethanolamine, diethanolamine, and triethylamine, sulfur-containing compounds such as dimethylsulfoxide, sulfolane, and thiodiethanol, propylene carbonate, and ethylene carbonate. etc.
It is preferable to use an organic solvent having a boiling point of 250° C. or less because it not only functions as a wetting agent but also provides good drying properties.

Polyol compounds having 8 or more carbon atoms and glycol ether compounds are also preferably used. Specific examples of polyol compounds having 8 or more carbon atoms include 2-ethyl-1,3-hexanediol and 2,2,4-trimethyl-1,3-pentanediol.
Specific examples of glycol ether compounds include polyhydric alcohol alkyls such as ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, and propylene glycol monoethyl ether. Ethers; polyhydric alcohol aryl ethers such as ethylene glycol monophenyl ether, ethylene glycol monobenzyl ether, and the like.

The content of the organic solvent in the ink is not particularly limited and can be appropriately selected according to the purpose. 20% by mass or more and 60% by mass or less is more preferable.

<Water>
The content of water in the surface treatment composition is not particularly limited and can be appropriately selected according to the purpose. , 20% by mass to 60% by mass.

<Other additives>
If necessary, a coagulant, a surfactant, an antifoaming agent, an antiseptic/antifungal agent, an antirust agent, a pH adjuster, and the like may be added to the surface treatment composition. The type of flocculant is not particularly limited, and examples thereof include water-soluble cationic polymers, acids, polyvalent metal salts, and the like.

<<Polyvalent metal salt>>
The polyvalent metal salt causes the pigment in the ink to quickly coagulate after droplet deposition, suppress color bleeding, and improve color developability.
Examples of polyvalent metal compounds include, but are not limited to, titanium compounds, chromium compounds, copper compounds, cobalt compounds, strontium compounds, barium compounds, iron compounds, aluminum compounds, calcium compounds, magnesium compounds and nickel. compounds, salts thereof (polyvalent metal salts), and the like.

Among these polyvalent metal compounds, one or more selected from the group consisting of calcium compounds, magnesium compounds, and nickel compounds are preferable because they can effectively aggregate the pigment, and alkaline earth metals such as calcium and magnesium. is more preferred.
Incidentally, the polyvalent metal compound is preferably ionic. In particular, when the polyvalent metal compound is a calcium salt, the stability of the reaction solution is improved.

Specific examples of the above polyvalent metal compounds include calcium carbonate, calcium nitrate, calcium chloride, calcium acetate, calcium sulfate, magnesium chloride, magnesium acetate, magnesium sulfate, barium sulfate, zinc sulfide, zinc carbonate, aluminum silicate, and calcium silicate. , magnesium silicate, and aluminum hydroxide.
Among these, calcium acetate is preferable for the purpose of preventing the decrease in strength of the pre-coating layer (layer formed by the surface treatment composition) due to deliquescence.

When the concentration of the polyvalent metal ion in the entire surface treatment composition is 0.05 to 0.5 mol/kg, particularly excellent storage stability can be obtained and color bleeding can be suppressed, which is preferable. be.

<<Surfactant>>
Any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants, and anionic surfactants can be used as surfactants.
The silicone-based surfactant is not particularly limited and can be appropriately selected depending on the purpose. Among them, those that do not decompose even at high pH are preferable. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as water-based surfactants. As the silicone-based surfactant, a polyether-modified silicone-based surfactant can also be used, and examples thereof include compounds in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.

Examples of fluorine-based surfactants include perfluoroalkylsulfonic acid compounds, perfluoroalkylcarboxylic acid compounds, perfluoroalkylphosphoric acid ester compounds, perfluoroalkylethylene oxide adducts, and perfluoroalkyl ether groups in side chains. Polyoxyalkylene ether polymer compounds are particularly preferred due to their low foaming properties. Examples of the perfluoroalkylsulfonic acid compound include perfluoroalkylsulfonic acid and perfluoroalkylsulfonate. Examples of the perfluoroalkylcarboxylic acid compounds include perfluoroalkylcarboxylic acids and perfluoroalkylcarboxylic acid salts. As the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in a side chain, a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in a side chain, and a perfluoroalkyl ether group in a side chain Examples thereof include salts of polyoxyalkylene ether polymers. Counter ions of salts in these _{fluorosurfactants} include Li, Na, K, _NH4 , _NH3CH2CH2OH , _{NH2 ( CH2CH2OH} ) ₂ , and _{NH ( CH2CH2OH} ). ₃ and the like.

Examples of amphoteric surfactants include laurylaminopropionate, lauryldimethylbetaine, stearyldimethylbetaine, lauryldihydroxyethylbetaine and the like.
Nonionic surfactants include, for example, polyoxyethylene alkylphenyl ethers, polyoxyethylene alkyl esters, polyoxyethylene alkylamines, polyoxyethylene alkylamides, polyoxyethylene propylene block polymers, sorbitan fatty acid esters, polyoxyethylene sorbitan Examples include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of anionic surfactants include polyoxyethylene alkyl ether acetates, dodecylbenzene sulfonates, laurates, and salts of polyoxyethylene alkyl ether sulfates.
These may be used individually by 1 type, or may use 2 or more types together.

The content of the surfactant in the surface treatment composition is not particularly limited and can be appropriately selected according to the purpose. 0.001% by mass or more and 5% by mass or less is preferable, and 0.05% by mass or more and 5% by mass or less is more preferable.

<< Defoamer >>
The antifoaming agent is not particularly limited, and examples thereof include silicone antifoaming agents, polyether antifoaming agents, and fatty acid ester antifoaming agents. These may be used individually by 1 type, or may use 2 or more types together. Among these, silicone-based antifoaming agents are preferred because of their excellent foam breaking effect.

<< Antiseptic antifungal agent >>
The antiseptic and antifungal agent is not particularly limited, and examples thereof include 1,2-benzisothiazolin-3-one.

<<Antirust agent>>
The rust inhibitor is not particularly limited, and examples thereof include acidic sulfites and sodium thiosulfate.

<<pH adjuster>>
The pH adjuster is not particularly limited as long as it can adjust the pH to 7 or higher, and examples thereof include amines such as diethanolamine and triethanolamine.
The physical properties of the ink are not particularly limited and can be appropriately selected depending on the intended purpose. For example, viscosity, surface tension, pH and the like are preferably within the following ranges.

(non-white ink and white ink)
Next, the non-white ink and the white ink in the present invention will be explained.
The non-white ink contains water, an organic solvent and acrylic resin particles, and the white ink contains water, an organic solvent, acrylic resin particles and a white colorant.
Hereinafter, unless otherwise specified, the term "ink" will be used to describe non-white ink and white ink without distinguishing between them.

<Acrylic resin particles>
By adding acrylic resin particles to the ink of the present invention, the adhesion between the ink layers can be enhanced.
As the acrylic resin particles used in the ink, appropriately synthesized particles may be used, or commercially available products may be used.
Commercially available products include, for example, Microgel E-1002, E-5002 (styrene-acrylic resin particles, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 (acrylic resin particles, manufactured by Dainippon Ink and Chemicals), Boncoat 5454 ( Styrene-acrylic resin particles, manufactured by Dainippon Ink and Chemicals), SAE-1014 (styrene-acrylic resin particles, manufactured by Nippon Zeon), Saibinol SK-200 (acrylic resin particles, manufactured by Saiden Chemical Co., Ltd.), Primal AC-22, AC-61 (acrylic resin particles, manufactured by Rohm and Haas), Nanocryl SBCX-2821, 3689 (acrylic silicone resin particles, manufactured by Toyo Ink Mfg. Co., Ltd.), and the like.

The glass transition temperature Tg of the acrylic resin particles in the ink is preferably −30 to 100° C., more preferably 0 to 100° C., more preferably 12 to 82 from the viewpoint of good ejection reliability and abrasion resistance. °C is more preferred. The Tg of the acrylic resin particles can be measured by DSC (Thermo plus EVO2/DSC manufactured by Rigaku Corporation).

The content of the acrylic resin particles is not particularly limited and can be appropriately selected according to the purpose, but is preferably 1 to 30% by mass based on the total amount of the ink.

The volume average particle diameter of the acrylic resin particles is not particularly limited and can be appropriately selected according to the intended purpose. The volume average particle diameter can be measured, for example, using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

<Water, organic solvent>
The water and organic solvent contained in the ink can have the same composition as the surface treatment composition described above.

<Colorant>
The coloring agent used in the white ink is not particularly limited as long as it exhibits white color, and can be appropriately selected depending on the purpose. Examples thereof include inorganic white pigments, organic white pigments, and hollow particles. These may be used individually by 1 type, or may use 2 or more types together. Among these, inorganic white pigments and hollow resin particles are preferred. In addition, "non-white" means colored or colorless other than white.

ISO-2469 (JIS-8148) is used as a standard for the whiteness of white ink, and generally when the value is 70 or more, it is used as a white colorant.
White particles having a hollow structure (hollow particles) may be used for the white ink, and examples of the white particles having a hollow structure include hollow resin particles and hollow inorganic particles.

Examples of the inorganic white pigment include alkaline earth metal sulfates such as barium sulfate, alkaline earth metal carbonates such as calcium carbonate, silicas such as finely divided silicic acid and synthetic silicates, calcium silicate, Alumina, alumina hydrate, titanium oxide, zinc oxide, talc, clay and the like. These may be used individually by 1 type, or may use 2 or more types together. Among these, titanium oxide is preferred.

Examples of the resin composition of the hollow resin particles include acrylic resins such as acrylic resins, styrene-acrylic resins and crosslinked styrene-acrylic resins, urethane resins, and maleic resins.

Materials for the inorganic hollow particles include, for example, oxides, nitrides, and oxynitrides of white metals such as silicon, aluminum, titanium, strontium, and zirconium, and inorganic compounds such as various glasses and silica.

Examples of non-white ink include color ink, black ink, gray ink, clear ink, and metallic ink. The clear ink means an ink that does not contain a coloring agent and is mainly composed of resin particles, an organic solvent and water. Even when clear ink is used as the non-white ink, according to the present invention, bleeding at the boundary between white ink and clear ink can be suppressed, and bleeding at the boundary between color ink and clear ink can be suppressed. can do.

Examples of the color ink include cyan ink, magenta ink, yellow ink, light cyan ink, light magenta ink, red ink, green ink, blue ink, orange ink, and violet ink.

The non-white ink may contain a coloring agent other than white, and the coloring agent used in the non-white ink is not particularly limited as long as it exhibits a non-white color, and can be appropriately selected according to the purpose. can be used, and dyes and pigments can be used. These may be used individually by 1 type, or may use 2 or more types together.

Among these, pigments are preferred. Examples of the pigment include inorganic pigments and organic pigments.

Examples of the inorganic pigments include titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow. and carbon black. These may be used individually by 1 type, and may use 2 or more types together.
Among these pigments, those having good affinity with the solvent are preferably used.
In addition, hollow resin particles and inorganic hollow particles can also be used in non-white ink.

Examples of pigments for black include carbon blacks (C.I. Pigment Black 7) such as furnace black, lamp black, acetylene black, and channel black, copper, and iron (C.I. Pigment Black 11). , aniline black (C.I. Pigment Black 1) and other organic pigments. These may be used individually by 1 type, and may use 2 or more types together.

For color, for example, C.I. I. Pigment yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42 (yellow iron oxide), 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104 , 108, 109, 110, 117, 120, 138, 150, 153, 155; I. Pigment Orange 5, 13, 16, 17, 36, 43, 51; C.I. I. Pigment Red 1, 2, 3, 5, 17, 22, 23, 31, 38, 48:2, 48:2 (Permanent Red 2B (Ca)), 48:3, 48:4, 49:1, 52: 2, 53:1, 57:1 (brilliant carmine 6B), 60:1, 63:1, 63:2, 64:1, 81, 83, 88, 101 (red red), 104, 105, 106, 108 ( cadmium red), 112, 114, 122 (quinacridone magenta), 123, 146, 149, 166, 168, 170, 172, 177, 178, 179, 185, 190, 193, 209, 219; I. Pigment Violet 1 (rhodamine lake), 3, 5:1, 16, 19, 23, 38, C.I. I. Pigment Blue 1, 2, 15 (phthalocyanine blue), 15:1, 15:2, 15:3 (phthalocyanine blue), 16, 17:1, 56, 60, 63; C.I. I. Pigment Green 1, 4, 7, 8, 10, 17, 18, 36 and the like. These may be used individually by 1 type, and may use 2 or more types together.

Examples of the dye include C.I. I. Acid Yellow 17, 23, 42, 44, 79, 142; C.I. I. Acid Red 52, 80, 82, 249, 254, 289; C.I. I. Acid Blue 9, 45, 249; C.I. I. Acid Black 1, 2, 24, 94; C.I. I. Food Black 1, 2; C.I. I. Direct Yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173; C.I. I. Direct Red 1, 4, 9, 80, 81, 225, 227; C.I. I. Direct Blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202; C.I. I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195; C.I. I. Reactive Red 14, 32, 55, 79, 249; C.I. I. Reactive Black 3, 4, 35 and the like. These may be used individually by 1 type, and may use 2 or more types together.

Colorants used in metallic inks include fine powders obtained by finely pulverizing a single metal, an alloy, or a metal compound. More specifically, any one or more of a group of simple metals consisting of aluminum, silver, gold, nickel, chromium, tin, zinc, indium, titanium, silicon, copper, or platinum, Alternatively, it may be an alloy obtained by combining a group of these metals. In addition, those obtained by finely pulverizing any one or a plurality of oxides, nitrides, sulfides, or carbides of these group of single metals or alloys are also included.

The content of the colorant in the ink is preferably 0.1% by mass or more and 15% by mass or less, more preferably 1% by mass or more and 10% by mass, from the viewpoints of improving image density, good fixability and ejection stability. It is below.

<<Pigment Dispersion>>
Inks can be obtained by mixing materials such as water and organic solvents with colorants. Ink can also be produced by mixing a pigment, water, a dispersant, and the like to form a pigment dispersion, and then mixing materials such as water and an organic solvent.

In order to disperse the pigment in the ink, a method of introducing a hydrophilic functional group into the pigment to make it a self-dispersing pigment, a method of coating the surface of the pigment with a resin and dispersing it, a method of dispersing using a dispersant, etc.

As a method of making a self-dispersing pigment by introducing a hydrophilic functional group into a pigment, for example, a self-dispersing pigment that is dispersible in water by adding a functional group such as a sulfone group or a carboxyl group to a pigment (for example, carbon). can be used.

As a method for dispersing the pigment by coating the surface of the pigment with a resin, a method in which the pigment is encapsulated in microcapsules and dispersible in water can be used. This can be rephrased as a resin-coated pigment. In this case, all the pigments mixed in the ink need not be coated with a resin, and uncoated pigments or partially coated pigments may be dispersed in the ink as long as the effects of the present invention are not impaired. may be

Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular-weight dispersant and high-molecular-weight dispersant typified by surfactants.
As the dispersant, it is possible to use, for example, anionic surfactants, cationic surfactants, amphoteric surfactants, nonionic surfactants, etc. depending on the pigment.
RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and sodium naphthalenesulfonate formalin condensate can also be suitably used as a dispersant.
A dispersing agent may be used individually by 1 type, or may use 2 or more types together.

The pigment dispersion can be obtained by dispersing water, a pigment, a pigment dispersant, and optionally other components, and adjusting the particle size. Dispersion should be carried out using a disperser.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the non-white pigment in the non-white ink has good dispersion stability and high image quality such as ejection stability and image density. , the volume average particle diameter is preferably 30 to 110 nm.
Further, from the viewpoint of obtaining high dispersion stability and high whiteness, the hollow resin particles in the white ink preferably have an average volume particle size of 200 to 1000 nm. The inorganic hollow particles preferably have an average volume particle diameter of 10 to 200 nm in order to obtain high dispersion stability and high whiteness.
The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).

The volume average particle size of the inorganic white pigment is preferably 100 nm or more and 350 nm or less, more preferably 200 nm or more and 300 nm or less. When the volume average particle diameter is 100 nm or more, the concealability can be improved. The volume-average particle size of the white colorant can be measured by a particle size distribution measuring apparatus based on a laser diffraction scattering method.

The content of the pigment in the pigment dispersion is not particularly limited and can be appropriately selected according to the purpose. % or more and 50 mass % or less is preferable, and 0.1 mass % or more and 30 mass % or less is more preferable.

The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator, or the like, if necessary.

<Other ingredients>
As with the surface treatment composition, the ink of the present invention may optionally contain a flocculating agent, a surfactant, an antifoaming agent, an antiseptic and antifungal agent, an antirust agent, a pH adjuster, and the like. The specific examples described for the surface treatment composition can be used.

<Example of ink manufacturing method>
The ink in the present invention is prepared, for example, by dispersing or dissolving the above components in an aqueous medium and, if necessary, stirring and mixing. Stirring and mixing can be carried out with a stirrer using ordinary stirring blades, a magnetic stirrer, a high-speed disperser, or the like.

<Physical properties of ink>
The physical properties of the ink are not particularly limited and can be appropriately selected depending on the intended purpose. For example, viscosity, surface tension, pH and the like are preferably within the following ranges.
The viscosity of the ink at 25° C. is preferably 5 mPa·s or more and 30 mPa·s or less, more preferably 5 mPa·s or more and 25 mPa·s or less, from the viewpoint of improving the print density and character quality and obtaining good ejection properties. more preferred. Here, the viscosity can be measured using, for example, a rotational viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.). Measurement conditions are 25° C., standard cone rotor (1°34′×R24), sample liquid volume 1.2 mL, rotation speed 50 rpm, 3 minutes.
The surface tension of the ink is preferably 35 mN/m or less, more preferably 32 mN/m or less at 25° C., from the viewpoint that the ink is appropriately leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably from 7 to 12, more preferably from 8 to 11, from the viewpoint of preventing corrosion of metal members in contact with the liquid.

(recoding media)
The recording medium (sometimes referred to as a base material, etc.) used in the present invention can be used without particular limitation, and plain paper, glossy paper, special paper, cloth, etc. can also be used. can be used particularly preferably for

The impermeable substrate in the present invention refers to a substrate having a surface with low water permeability, absorbency and/or adsorption, and is a material that has many cavities inside but does not open to the outside. is also included. More quantitatively, it refers to a substrate having a water absorption of 10 mL/m ² or less from the start of contact to 30 msec ^1/2 in the Bristow method.

Among the impermeable substrates, good adhesion is obtained particularly to resin films such as polypropylene film (OPP film), polyethylene terephthalate film (PET film) and nylon film (ONY film).

Examples of the polypropylene film include P-2002, P-2161 and P-4166 manufactured by Toyobo Co., Ltd., PA-20, PA-30 and PA-20W manufactured by SUNTOX, FOA, FOS and FOR manufactured by Futamura Chemical. be done.
Examples of the polyethylene terephthalate film include E-5100 and E-5102 manufactured by Toyobo Co., Ltd., P60 and P375 manufactured by Toray Industries, Inc., and G2, G2P2, K and SL manufactured by Teijin DuPont Films.
Examples of the nylon film include Harden Film N-1100, N-1102 and N-1200 manufactured by Toyobo Co., Ltd., and ON, NX, MS and NK manufactured by Unitika.

(Image forming method and image forming apparatus)
The image forming method of the present invention is an image forming method for forming an image on a non-permeable substrate, wherein a surface treatment composition containing water, an organic solvent and urethane resin particles is applied onto the non-permeable substrate. applying a non-white ink containing water, an organic solvent and acrylic resin particles; and applying a white ink containing water, an organic solvent, acrylic resin particles and a white colorant. characterized by

The image forming apparatus of the present invention is an image forming apparatus for forming an image on an impermeable substrate, wherein a surface treatment composition containing water, an organic solvent and urethane resin particles is applied onto the impermeable substrate. means for applying; means for applying non-white ink containing water, organic solvent and acrylic resin particles; and means for applying white ink containing water, organic solvent, acrylic resin particles and white colorant. characterized by

The surface treatment composition, non-white ink, and white ink may be those described above. The method of applying the surface treatment composition, the non-white ink, and the white ink is not particularly limited and can be changed as appropriate, but an inkjet recording method is preferably used. In addition to the inkjet recording method, for example, a blade coating method, a gravure coating method, a bar coating method, a roll coating method, a dip coating method, a curtain coating method, a slide coating method, a die coating method and a spray coating method can be used.

The image forming method of the present invention preferably includes a step of surface-modifying the impermeable substrate (surface-modifying step). By performing the surface modification step, unevenness can be suppressed when the composition for surface treatment is applied to the impermeable base material, and adhesion can be further improved.

Examples of surface modification include corona discharge treatment, streamer discharge treatment, atmospheric pressure plasma treatment, flame treatment, and ultraviolet irradiation treatment. These treatment methods can be carried out using known equipment.

Among the above treatment methods, corona discharge treatment and streamer discharge treatment are preferred. These are preferably used because they are superior to atmospheric pressure plasma treatment, flame treatment, and ultraviolet irradiation treatment in terms of discharge output stability and can perform uniform surface treatment on the recording surface.

In the image forming method of the present invention, heat treatment is preferably performed after applying the ink. By performing the heat treatment, the residual solvent in the ink coating film can be reduced, and the adhesion can be further improved.

That is, the image forming method of the present invention may have a heat treatment step (1) in which heat treatment is performed after applying the non-white ink, and a heat treatment step (2) in which heat treatment is performed after applying the white ink. preferable. Although it is more preferable to have both the heat treatment step (1) and the heat treatment step (2), the above effect can be expected even if one of them is used.

The heating temperature in the heat treatment step is not particularly limited and can be changed as appropriate, but is preferably 50 to 130°C. Further, the heating time in the heat treatment step is not particularly limited and can be changed as appropriate. For example, it is preferably 1 to 120 seconds, more preferably 1 to 30 seconds.

Also, the non-white ink may contain a coloring agent other than white, and the step of applying the non-white ink by changing the type of coloring agent may be performed multiple times. When performing multiple times, all the non-white inks must contain acrylic resin particles.

The image forming method of the present invention is suitable for use in various inkjet recording apparatuses, such as printers, facsimile machines, copiers, printer/fax/copier complex machines, stereolithography machines, and the like.

In the present invention, a recording apparatus and a recording method refer to an apparatus capable of ejecting ink, various treatment liquids, and the like onto a recording medium, and a method of performing recording using the apparatus. A recording medium means a medium to which ink or various processing liquids can adhere even temporarily.
This recording apparatus can include not only a head portion for ejecting ink, but also means for feeding, conveying, and discharging a recording medium, and other devices called pre-processing devices and post-processing devices. .

The recording apparatus and recording method may have heating means used in the heating process and drying means used in the drying process. The heating means and drying means include, for example, means for heating and drying the printing surface and the back surface of the recording medium. The heating means and drying means are not particularly limited, but for example, hot air heaters and infrared heaters can be used. Heating and drying can be performed before, during, or after printing.

Also, the recording apparatus and recording method are not limited to those that visualize significant images such as characters and graphics with ink. For example, it includes those that form patterns such as geometric patterns, and those that form three-dimensional images.
In addition, unless otherwise specified, the recording apparatus includes both a serial type apparatus in which the ejection head is moved and a line type apparatus in which the ejection head is not moved.
Furthermore, this recording device can be used not only as a desktop type, but also as a wide recording device that can print on A0 size recording media, and for example, can use continuous paper wound into a roll as a recording medium. A continuous feed printer is also included.

An example of a recording apparatus will be described with reference to FIGS. 1 and 2. FIG. FIG. 1 is a perspective explanatory view of the device. FIG. 2 is a perspective explanatory view of the main tank. An image forming apparatus 400 as an example of a recording apparatus is a serial image forming apparatus. A mechanical unit 420 is provided inside the exterior 401 of the image forming apparatus 400 . Each ink container 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), and yellow (Y) is packed with, for example, an aluminum laminated film. It is made up of members. The ink containing portion 411 is housed, for example, in a container case 414 made of plastic. Thus, the main tank 410 is used as an ink cartridge for each color.

On the other hand, a cartridge holder 404 is provided on the far side of the opening when the cover 401c of the apparatus main body is opened. A main tank 410 is detachably attached to the cartridge holder 404 . As a result, each ink discharge port 413 of the main tank 410 communicates with the ejection head 434 for each color via the supply tube 436 for each color, and ink can be ejected from the ejection head 434 onto the printing medium.

This recording apparatus can include not only a portion that ejects ink, but also devices called pre-processing devices and post-processing devices. A configuration may be adopted in which the surface treatment composition is applied by the pre-treatment device and the white ink is applied by the post-treatment device.

As an aspect of the pre-treatment device and the post-treatment device, it has a pre-treatment liquid and a post-treatment liquid in the same manner as in the case of inks such as black (K), cyan (C), magenta (M), and yellow (Y). There is a mode in which a liquid container and a liquid ejection head are added, and the pretreatment liquid and the posttreatment liquid are ejected by an inkjet recording method.
As another aspect of the pre-treatment device and the post-treatment device, there is an aspect in which a pre-treatment device and a post-treatment device using a method other than the inkjet recording method, such as a blade coating method, a roll coating method, and a spray coating method, are provided.

(Manufacturing method of printed matter and printed matter)
The method for producing a printed matter of the present invention is a method for producing a printed matter in which an image is formed on a non-permeable base material, wherein a surface treatment composition containing water, an organic solvent and urethane resin particles is added to the non-permeable base material. A step of applying on a material, a step of applying a non-white ink containing water, an organic solvent and acrylic resin particles, a step of applying a white ink containing water, an organic solvent, acrylic resin particles and a white colorant; characterized by having

FIG. 3 shows a cross-sectional view of an example of the printed matter in the present invention. In the printed matter of this embodiment, a precoat layer 2, a non-white ink layer 3, and a white ink layer 4 are formed on a base material 1 in this order. The precoat layer 2 is a layer made of the surface treatment composition, the non-white ink layer 3 is a layer made of the non-white ink, and the white ink layer 4 is a layer made of the white ink.

In the printed matter of this embodiment, the thickness of each layer is not particularly limited, and can be changed as appropriate. For example, the precoat layer 2 preferably has a thickness of 0.05 to 0.5 μm, the non-white ink layer 3 preferably has a thickness of 0.5 to 3 μm, and the white ink layer 4 preferably has a thickness of 1 to 4 μm.

In the above example, one type of non-white ink is used, but the present invention is not limited to this. The non-white ink may contain a colorant other than white, and the step of applying the non-white ink with different types of colorants may be performed multiple times to form a plurality of non-white ink layers. In this case, the locations where the plurality of non-white ink layers are formed can be changed as appropriate, and they may be formed overlapping in the thickness direction, or may be formed adjacent to each other in the planar direction.

EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following examples. In addition, "parts" in the examples represent "parts by mass", and "%" represents "% by mass" unless otherwise specified.

(Preparation of urethane resin emulsion)
<Preparation of urethane resin emulsion A>
In a reaction vessel fitted with a stirrer, reflux condenser, and thermometer, 1,500 g of Polylite OD-X-2420 (DIC, polyester polyol), 220 g of 2,2-dimethylolpropionic acid (DMPA), and N -Methylpyrrolidone (NMP) 1,347 g was charged under a nitrogen atmosphere and heated to 60° C. to dissolve DMPA.
Next, 1,445 g of 4,4′-dicyclohexylmethane diisocyanate and 2.6 g of dibutyltin dilaurate (catalyst) were added and heated to 90° C. for urethanization reaction over 5 hours to produce an isocyanate-terminated urethane prepolymer. Obtained. This reaction mixture was cooled to 80° C., and 4,340 g of the mixture containing 149 g of triethylamine was taken out and added to a mixed solution of 5,400 g of water and 15 g of triethylamine under strong stirring.
Next, 1,500 g of ice was added, 626 g of a 35% by mass 2-methyl-1,5-pentanediamine aqueous solution was added to carry out a chain extension reaction, and the solvent was distilled off so that the solid content concentration was 30% by mass. Then, the resulting resin emulsion is dispersed with a paint conditioner (manufactured by Red Devil Co., the speed can be adjusted in the range of 50 to 1,425 rpm) to obtain a polyester urethane resin emulsion with a solid content concentration of 40.0% by mass and a Tg of 10 ° C. got an A.
In addition, Tg was measured by DSC (Thermo plus EVO2/DSC manufactured by Rigaku Corporation).

<Preparation of urethane resin emulsion B>
In the preparation of the urethane resin emulsion A, the solid content A polyether-based urethane resin emulsion B having a concentration of 30% by mass and a Tg of 75° C. was obtained.

<Adjustment of urethane resin emulsion C>
287.9 parts of Mn 2,000 crystalline polycarbonate diol (Duranol T6002, manufactured by Asahi Kasei Chemicals), 3.6 parts of 1,4-butanediol, and 8.9 parts of DMPA were placed in a simple pressurized reactor equipped with a stirrer and a heater. , 98.3 parts of hydrogenated MDI (diphenylmethane diisocyanate) and 326.2 parts of acetone were charged while introducing nitrogen. After that, the mixture was heated to 90° C. and a urethanization reaction was carried out over 8 hours to produce a prepolymer. After cooling the reaction mixture to 40° C., 6.8 parts of triethylamine was added and mixed, and 568.8 parts of water was added and emulsified with a rotor-stator type mechanical emulsifier to obtain an aqueous dispersion. . 28.1 parts of a 10% aqueous ethylenediamine solution was added to the obtained aqueous dispersion with stirring, and the mixture was stirred at 50°C for 5 hours to carry out a chain elongation reaction. Thereafter, acetone was removed at 65°C under reduced pressure, and the water content was adjusted to obtain a polycarbonate-based urethane resin emulsion C having a solid content concentration of 40% by mass and a Tg of -20°C.

(Preparation of acrylic resin particle emulsion)
<Preparation of acrylic resin emulsion D>
As the acrylic resin emulsion D, Boncoat CF-6140 (manufactured by DIC, Tg 12° C.) was used.

<Preparation of acrylic resin emulsion E>
As the acrylic resin emulsion E, Vinyblan 2682 (manufactured by Nissin Chemical Industry Co., Ltd., Tg-30°C) was used.

<Preparation of acrylic resin emulsion F>
As acrylic resin emulsion F, JE-1056 (manufactured by Seiko PMC, Tg 82° C.) was used.

(Preparation of composition for surface treatment)
<Surface treatment composition preparation example 1>
After preparing the following composition, the mixture was mixed and stirred, and filtered through a 5 μm filter (Minisart manufactured by Sartorius) to obtain a surface treatment composition of Surface Treatment Composition Preparation Example 1.

1,2-propanediol 10 parts Emulgen LS-106 (surfactant manufactured by Kao Corporation) 1 part Calcium acetate monohydrate 1.76 parts Polyester-based urethane resin emulsion A (as solid content) 10 parts Proxel LV (Avecia) Preservative) 0.1 part Ion-exchanged water 77.14 parts

<Surface treatment composition preparation examples 2 to 10>
Surface treatment compositions of Surface Treatment Composition Preparation Examples 2 to 10 were obtained in the same manner as in Surface Treatment Composition Preparation Example 1 using the formulations shown in Table 1.

In Table 1, the contents of emulsions A to F represent the solid content.

(Ink preparation)
<Preparation of pigment dispersion>
<<Preparation of Black Pigment Dispersion>>
Carbon black manufactured by Tokai Carbon Co., Ltd.: Seast SP (SRF-LS) 100 g is added to 3000 mL of 2.5 N (regulation) sodium hypochlorite solution, stirred at a temperature of 60 ° C. and a speed of 300 rpm, and reacted for 10 hours. A pigment having carboxylic acid groups on the surface of the carbon black was obtained. This reaction solution was filtered, and the filtered carbon black was neutralized with a sodium hydroxide solution and subjected to ultrafiltration.
Next, the pigment dispersion and ion-exchanged water are subjected to ultrafiltration with a dialysis membrane, followed by ultrasonic dispersion to concentrate the solid content of the pigment to 20%. got

<<Preparation of Cyan Pigment Dispersion>>
In the preparation of the black dispersion, cyan having a volume average particle size of 75 nm was used in the same manner, except that the coloring material used was replaced with a copper phthalocyanine pigment (CI Pigment Blue 15:4, trade name: LX4033) manufactured by Toyo Ink Co., Ltd. A pigment dispersion was obtained.

<<Preparation of Magenta Pigment Dispersion>>
A magenta pigment dispersion having a volume average particle diameter of 73 nm was obtained in the same manner as in the preparation of the black dispersion, except that Pigment Red 122 manufactured by Sun Chemical Co. was used as the coloring material.

<<Preparation of Yellow Pigment Dispersion>>
Yellow pigment dispersion with a volume average particle diameter of 82 nm in the same manner except that the coloring material used in the preparation of the black dispersion was replaced with a yellow pigment manufactured by Dainichiseika Kogyo Co., Ltd. (Pigment Yellow 74, trade name: Yellow No. 46) got a body

<<Adjustment of White Pigment Dispersion>>
25 g of titanium oxide STR-100W (manufactured by Sakai Chemical Industry Co., Ltd.), 5 g of pigment dispersant TEGO Dispers 651 (manufactured by Evonik), and 70 g of water are mixed and milled in a bead mill (manufactured by Research Labo, Shinmaru Enterprises) to a diameter of 0.3 mm. zirconia beads were dispersed at a filling rate of 60% and 8 m/s for 5 minutes to obtain a white pigment dispersion having a volume average particle size of 285 nm.

<Ink preparation method>
The inks were prepared by mixing and stirring the formulations shown in Tables 2 and 3, and filtering the non-white ink through a 0.2 μm polypropylene filter and the white ink through a 0.5 μm polypropylene filter. The surfactant used was FS-300 (fluorinated surfactant manufactured by DuPont).

In Tables 2 and 3, the content of the pigment dispersion and the content of emulsions A to F represent the solid content.

(Example 1)
As shown in Table 4, the following evaluations were performed using the surface treatment composition, non-white ink, and white ink.

<Evaluation of printed part adhesion>
An inkjet printer (IPSiO GXe5500 manufactured by Ricoh Co., Ltd.) set as an image forming apparatus having a bar coater is filled with non-white ink and white ink as the ink for printing by the inkjet method, and the liquid for surface treatment is applied using the bar coater. The composition was filled.
OPP film (Pylen P2102, manufactured by Toyobo), PET film (Spet E5100, manufactured by Toyobo), and ONY film (Harden N1100, manufactured by Toyobo) were coated with a bar coater No. 1, the surface treatment composition was applied and dried. Next, a test image was printed with the non-white ink 1, and a test image was further printed with the non-white ink 2 so as not to overlap the non-white ink 1, and dried at 80° C. for 2 minutes. Thereafter, a white ink solid image was printed and dried at 80° C. for 2 minutes to obtain a printed matter. The resulting printed material was subjected to a cross-cut peeling test using a cloth adhesive tape (123LW-50 manufactured by Nichiban Co., Ltd.) and evaluated according to the following criteria. Up to B is the allowable range.
[Evaluation criteria]
A: Peeling is not observed in any of the 100 squares.
B: One or more to five or less of 100 squares were peeled off.
C: 6 or more of 100 squares were peeled off.

<Evaluation of Color Boundary Bleeding>
The following evaluation of color boundary bleeding was performed on the printed matter obtained in the above evaluation of the adhesion of the printed portion. Examine the presence or absence of bleeding in the portion where the two colors (non-white inks 1 and 2) of the print pattern are in contact (where ◯ does not occur, and where bleeding occurs) is checked at each duty, Evaluation was made according to the following criteria. Up to B is the allowable range.
[Evaluation criteria]
A: ◯ up to a duty of 70%, and printing is possible up to this duty without bleeding.
B: ◯ up to a duty of 50%, and printing is possible up to this duty without bleeding.
C: A duty of 40% or more is x, and bleeding occurs in printing with a duty of 40%.

(Examples 2 to 18)
Evaluation was performed in the same manner as in Example 1, except that the surface treatment composition, non-white ink, and white ink were changed as shown in Tables 4 and 5.

(Example 19)
Evaluation was performed in the same manner as in Example 1, except that each film was not subjected to corona treatment.

(Example 20)
Evaluation was performed in the same manner as in Example 1, except that the heat treatment was not performed after printing with the non-white ink.

(Example 21)
Evaluation was performed in the same manner as in Example 1, except that the heat treatment was not performed after printing with the white ink.

(Comparative Examples 1 to 18)
Evaluation was performed in the same manner as in Example 1, except that the surface treatment composition, non-white ink, and white ink were changed as shown in Tables 6 and 7.

(Comparative Example 19)
Evaluation was performed in the same manner as in Comparative Example 1, except that the surface treatment composition was not applied.

In Tables 4 to 7, heat treatment (1) indicates heat treatment after non-white ink printing, and heat treatment (2) indicates heat treatment after white ink printing.

Examples 1, 3, 9, 10, 12, 15 and 16 are preferred examples of the invention. In these examples, all substrates were evaluated as A for both adhesion and color boundary bleeding.

Examples 4, 11 and 18 are examples in which the Tg of the urethane resin particles deviates from -25 to 25°C. Adhesion to the OPP film was evaluated as B, but it can be said that there is no problem in use.

Examples 2, 5, 8, 11, 14 and 17 are examples in which the Tg of the acrylic resin particles deviates from 0 to 100°C. Adhesion with OPP film and lamination strength are evaluated as B, but it can be said that there is no problem in use.

Examples 6, 7, 13 and 14 are examples in which the content of urethane resin particles in the surface treatment composition deviates from 0.5% by mass to 20% by mass relative to the surface treatment composition. Since the amount of urethane resin particles in the surface treatment composition of Examples 6 and 13 is small, the film cannot be sufficiently covered. However, since it is rated B, it can be said that there is no problem in use.

Example 19 is an example in which the substrate is not subjected to surface modification treatment. In this case, unevenness occurs during coating of the surface treatment composition, and since there is no function to increase adhesion, adhesion and color boundary bleeding are reduced. .

Examples 20 and 21 are examples in which heat treatment is not performed after ink printing. When the heat treatment is not performed after the ink printing, the effects of the resin in the ink do not progress rapidly, and the adhesion and bleeding at the boundary between colors are lowered.

Comparative Examples 1 to 6 are examples in which urethane resin particles are not used in the surface treatment composition.
Comparative Examples 7 to 12 are examples in which the resin in either non-white ink 1 or 2 is not an acrylic resin.
Comparative Examples 13 to 18 are examples in which acrylic resin particles are not used in the white ink.
Comparative Examples 1 to 18 were evaluated as C for either the adhesiveness or the color boundary bleeding evaluation, and it can be seen that the three substrates of OPP, PET, and ONY did not achieve both adhesion and image quality.
Comparative Example 19 is an example in which no surface treatment composition is applied. Comparative Example 19 had problems in both adhesion and evaluation of color boundary bleeding.

The contents of calcium acetate in the above surface treatment compositions were 1.76 parts and 3.52 parts, but the concentration of calcium acetate did not affect the evaluation results.

(Example 22)
Evaluation was performed in the same manner as in Example 1, except that non-white ink 2 was not used. Regarding the evaluation of color boundary bleeding, the presence or absence of bleeding at a portion where non-white (black) and white are in contact was examined for each duty and evaluated according to the above criteria.

(Comparative Example 20)
Evaluation was performed in the same manner as in Comparative Example 1, except that the non-white ink 2 was not used. As for the evaluation of color boundary bleeding, in the same manner as in Example 22, the presence or absence of bleeding at the portion where non-white (black) and white were in contact was examined for each duty and evaluated according to the above criteria.

(Comparative Example 21)
In Comparative Example 10, evaluation was performed in the same manner as in Comparative Example 1, except that non-white ink 2 was not used. As for the evaluation of color boundary bleeding, in the same manner as in Example 22, the presence or absence of bleeding at the portion where non-white (black) and white were in contact was examined for each duty and evaluated according to the above criteria.

(Comparative Example 22)
In Comparative Example 13, evaluation was performed in the same manner as in Comparative Example 1, except that non-white ink 2 was not used. As for the evaluation of color boundary bleeding, in the same manner as in Example 22, the presence or absence of bleeding at the portion where non-white (black) and white were in contact was examined for each duty and evaluated according to the above criteria.

In Example 22, all the substrates were evaluated as A in terms of adhesion and color boundary bleeding.
Comparative Example 20 is an example in which urethane resin particles are not used in the surface treatment composition, Comparative Example 21 is an example in which the resin in the non-white ink is not an acrylic resin, and Comparative Example 22 is an example in which acrylic resin is used in the white ink. This is an example in which resin particles are not used. Comparative Examples 20 to 22 were evaluated as C for either the adhesiveness or the color boundary bleeding evaluation, indicating that the adhesiveness and the image quality were not compatible with the three substrates of OPP, PET, and ONY.

REFERENCE SIGNS LIST 1 base material 2 precoat layer 3 non-white ink layer 4 white ink layer 400 image forming apparatus 401 exterior of image forming apparatus 401c cover of apparatus main body 404 cartridge holder 410 main tank 410k, 410c, 410m, 410y black (K), cyan Main tanks for (C), magenta (M), and yellow (Y) 411 Ink storage unit 413 Ink discharge port 414 Storage container case 420 Mechanism unit 434 Ejection head 436 Supply tube

JP 2015-71738 A JP 2008-246837 A

Claims (9)

An image forming method for forming an image on a resin film,
applying a surface treatment composition containing water, an organic solvent, urethane resin particles and a flocculant onto the resin film;
After the step of applying the surface treatment composition onto the resin film, a step of applying a non-white ink containing water, an organic solvent, acrylic resin particles, and a colorant other than white;
A step of applying a white ink containing water, an organic solvent, acrylic resin particles, and a white colorant after the step of applying the non-white ink ,
The image forming method , wherein the urethane resin particles are selected from polyester-based urethane resin particles, polyether-based urethane resin particles and polycarbonate-based urethane resin particles . The non-white ink contains a colorant other than white,
2. The image forming method according to claim 1, wherein in the step of applying the non-white ink, the step of applying the non-white ink while changing the type of the colorant is performed a plurality of times. 3. The image forming method according to claim 1, wherein the urethane resin particles in the surface treatment composition have a glass transition temperature Tg of -25 to 25.degree. 4. The image forming method according to claim 1, wherein the urethane resin particles in the surface treatment composition are contained in an amount of 0.5 to 20% by mass with respect to the surface treatment composition. . 5. The image forming method according to claim 1, wherein the acrylic resin particles in the non-white ink and the white ink have a glass transition temperature Tg of 0 to 100.degree. Having a step of modifying the surface of the resin film ,
6. The image forming method according to claim 1, wherein the surface modification step is corona discharge treatment. 6. The method further comprises a first heat treatment step in which heat treatment is performed after applying the non-white ink, and a second heat treatment step in which heat treatment is performed after the white ink is applied. The image forming method according to any one of . An image forming apparatus for forming an image on a resin film,
means for applying a surface treatment composition containing water, an organic solvent, urethane resin particles and a flocculant onto the resin film;
means for applying a non-white ink containing water, an organic solvent, acrylic resin particles, and a colorant other than white, after applying the surface treatment composition onto the resin film;
and means for applying a white ink containing water, an organic solvent, acrylic resin particles and a white colorant after applying the non-white ink ,
The image forming apparatus , wherein the urethane resin particles are selected from polyester-based urethane resin particles, polyether-based urethane resin particles and polycarbonate-based urethane resin particles . A method for producing a printed matter in which an image is formed on a resin film,
applying a surface treatment composition containing water, an organic solvent, urethane resin particles and a flocculant onto the resin film;
After the step of applying the surface treatment composition onto the resin film, a step of applying a non-white ink containing water, an organic solvent, acrylic resin particles, and a colorant other than white;
A step of applying a white ink containing water, an organic solvent, acrylic resin particles, and a white colorant after the step of applying the non-white ink ,
A method for producing a printed matter, wherein the urethane resin particles are selected from polyester-based urethane resin particles, polyether-based urethane resin particles, and polycarbonate-based urethane resin particles .

Images