JP2017222744A - Ink set, printed matter, printing method, and printing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink set that has very high adhesiveness to an impermeable recording medium and allows high-gloss printed matter having excellent scrub resistance to be obtained.SOLUTION: The ink set includes a non-white ink and a white ink. In the ink set, the white ink contains water, an organic solvent, a color material, styrene acrylic resin particles, and at least one selected from acrylic urethane resin particles, polyester resin particles, and polyolefin-modified polyester-urethane resin particles, and the non-white ink contains water, an organic solvent, and styrene acrylic resin particles.SELECTED DRAWING: None

Description

  The present invention relates to an ink set, a printed matter, a printing method, and a printing apparatus.

  In order to improve durability such as light resistance, water resistance, and abrasion resistance in industrial applications such as advertising and billboards, for example, non-permeable recording media such as plastic films are used. Various inks used in the field have been developed.

As such an ink, for example, a solvent-based ink using an organic solvent as a solvent, an ultraviolet curable ink mainly containing a polymerizable monomer, and the like are widely used. However, there is a concern that the solvent-based ink may affect the environment due to evaporation of the organic solvent. The UV curable ink may have a limited choice of polymerizable monomers used from the viewpoint of safety.
Therefore, an ink set including an aqueous ink that has a low environmental load and can be directly recorded on a non-permeable recording medium has been proposed (for example, see Patent Documents 1 and 2).

In addition to industrial uses such as advertisements and signboards, for example, a technique for forming an image on a packaging material such as food, beverages, daily necessities and the like has been developed. In such applications, non-porous recording media such as plastic films are used, and inks for this purpose have been developed.
When printing on a non-porous recording medium such as the plastic film, the non-porous recording medium is often a transparent film. When printing on a transparent recording medium, it may be necessary to print not only color ink but also white ink. In some cases, the color ink is printed after the white ink is printed on the recording medium.
As a material of the plastic film, vinyl chloride has been generally used for industrial applications such as advertisements and signboards. Recently, polyethylene terephthalate (PET) has been used as a material for dechlorination for environmental reasons. And materials such as acrylic resin films are also used.
On the other hand, polypropylene resins, PET and nylon resins are generally used for packaging materials such as foods, beverages and daily necessities. Among these, a polypropylene resin film is frequently used because of its excellent tensile strength, transparency, and moisture resistance.

  An object of the present invention is to provide an ink set that has a very high adhesion to a non-penetrable recording medium and that provides a highly glossy printed matter having excellent abrasion resistance.

The ink set of the present invention as means for solving the above problems is an ink set having non-white ink and white ink,
The white ink contains water, an organic solvent, a coloring material, styrene acrylic resin particles, at least one selected from acrylic urethane resin particles, polyester resin particles, and polyolefin-modified polyester urethane resin particles,
The non-white ink contains water, an organic solvent, and styrene acrylic resin particles.

  ADVANTAGE OF THE INVENTION According to this invention, the ink set which can obtain the highly glossy printed matter which has very high adhesiveness with respect to a non-permeable recording medium and has the outstanding abrasion resistance can be provided.

FIG. 1 is a perspective explanatory view showing an example of a serial type image forming apparatus. FIG. 2 is a perspective explanatory view showing an example of a main tank of the apparatus of FIG.

(Ink set)
The ink set of the present invention is an ink set having a non-white ink and a white ink,
The white ink contains water, an organic solvent, a coloring material, styrene acrylic resin particles, at least one selected from acrylic urethane resin particles, polyester resin particles, and polyolefin-modified polyester urethane resin particles, Furthermore, other components are contained as necessary.
The non-white ink contains water, an organic solvent, and styrene acrylic resin particles, and further contains other components as necessary.

  In the ink set of the present invention, in the conventional ink set, the non-permeable recording medium such as a plastic film is often a transparent film, and from the point of increasing the image density of the obtained printed matter, a white ink is used, In some cases, recording is performed with non-white ink after the film is concealed. In such a case, it is based on the finding that the abrasion resistance of the printed matter is reduced. Further, in the conventional ink set, the image is peeled off from the non-permeable recording medium against the friction and the background portion of the non-permeable recording medium is exposed, or the background portion of the non-permeable recording medium is in close contact. However, this is based on the knowledge that the color of the image may change due to part of the surface of the image being peeled off.

Therefore, in the ink set of the present invention, the white ink and the non-white ink include styrene acrylic resin particles. When the white ink and the non-white ink contain the same styrene acrylic resin particles, the adhesion between the ink coating films of each color is improved, and the coating film can be prevented from being peeled off at the boundary of each color. Further, when the white ink and the non-white ink contain styrene acrylic resin particles, a highly glossy coating film can be obtained.
The acrylic urethane resin particles contained in the white ink greatly improve the adhesion with the non-permeable recording medium, and extremely high adhesion is obtained particularly when the recording medium is an acrylic resin film.
The polyester resin particles contained in the white ink greatly improve the adhesion to the non-permeable recording medium, and extremely high adhesion can be obtained particularly when the recording medium is a polyester resin film.
The polyolefin-modified polyester urethane resin particles contained in the white ink greatly improve the adhesion to the non-permeable recording medium, and particularly high adhesion can be obtained when the recording medium is a polypropylene resin film. .

<White ink>
In the white ink, the white ink contains water, an organic solvent, a coloring material, and resin particles, and further contains other components as necessary.
The white ink is preferably printed as a base on a non-permeable recording medium.

<< Resin particles >>
The resin particles contain styrene acrylic resin particles and resin particles (other resin particles) other than the styrene acrylic resin particles.
The other resin particles are at least one selected from acrylic urethane resin particles, polyester resin particles, and polyolefin-modified polyester urethane resin particles.

-Styrene acrylic resin particles-
When the white ink contains styrene acrylic resin particles, a highly glossy coating film can be obtained.
Moreover, since it is contained in all the colors of the said white ink and the said non-white ink, the adhesiveness of the coating films of each color can be raised and it can prevent that a coating film peels in the boundary of each color.

The styrene acrylic resin particles can be prepared by a well-known free radical emulsion polymerization method in an aqueous medium, and a homopolymer produced from one type of monomer or a copolymer produced from more than one type of monomer can be used. Polymers containing monomers that form water-insoluble homopolymers are preferred as well as copolymers of such monomers. It can also include monomers that form water-soluble homopolymers if the entire polymer composition is sufficiently water-insoluble to form a latex.
These polymers can be prepared by emulsion polymerization, solution polymerization, suspension polymerization, dispersion polymerization, ionic polymerization (cation, anion), Atomic Transfer Radical Polymerization, and other polymerization methods well known in the polymerization art.

An example of a preferred polymer is a styrene acrylic resin prepared by free radical polymerization of vinyl monomers in an aqueous emulsion. The polymer latex is preferably a homopolymer or copolymer or cross-linked polymer containing an ethylenically unsaturated hydrophobic monomer that produces a water-insoluble homopolymer, provided that the entire polymer composition is water-insoluble enough to form a latex. Also preferred are copolymers of monomers that also contain ethylenically unsaturated hydrophilic monomers that form water-soluble homopolymers.
The styrene acrylic resin can be produced by emulsion polymerization, dispersion polymerization, suspension polymerization, pulverization, or solution / bulk polymerization. Detailed information on this method and stabilizer is provided by quoting "Emulsion Polymerization and Emulsion Polymer" (PA Lovell, MS El-Asser, John Wiley & Sons Ltd., England, 1977). Included in this specification).

  A commercial item can be used as the styrene acrylic resin emulsion, and examples of the commercial item include J-450, J-734, J-7600, J-352, J-390, J-7100, J-. 741, J-74J, J-511, J-840, J-775, HRC-1645, HPD-71, PDX-6102B, JDX-5050 (styrene acrylic resin emulsion, manufactured by Johnson Polymer); UC-3900 ( Styrene acrylic resin emulsion, manufactured by Toa Gosei Co., Ltd.).

-Resin particles other than styrene acrylic resin particles (other resin particles)-
The other resin particles are at least one selected from acrylic urethane resin particles, polyester resin particles, and polyolefin-modified polyester urethane resin particles.
When the white ink contains the other resin particles, adhesion to a non-permeable recording medium such as a plastic film can be further improved. This is because when the white ink is dried on a recording medium and formed into a film in physical proximity to the resin particles, if they contain similar structures, they interact with each other to form a uniform film. This is because of being encouraged.

--Acrylic urethane resin particles--
By containing the acrylic urethane resin particles, the white ink can improve the adhesion to the non-permeable recording medium, and in particular, can obtain extremely high adhesion to the acrylic resin film.

  The acrylic urethane resin particles may be formed by reacting an acrylic polymer having a terminal hydroxyl group with a urethane chain having an isocyanate group at the end, as long as urethane and acrylic are chemically bonded. Examples include coalescence. There is no restriction | limiting in particular as said polymer, According to the objective, it can select suitably, A graft type or a block type may be sufficient. Moreover, a core shell type | mold which has a core part containing an acrylic resin and a shell part containing the urethane resin formed in the said core part surface may be sufficient.

  Hereinafter, the core-shell type in which the acrylic urethane resin particles have a core part made of an acrylic resin and a shell part made of a urethane resin will be described.

  The core-shell type acrylic urethane resin particles are not particularly limited and can be appropriately selected according to the purpose. For example, the core-shell type acrylic urethane resin particles can be obtained by seed polymerization, multistage polymerization, power feed method, or the like.

The core-shell type acrylic urethane resin particles are preferably used as a resin emulsion, and the resin emulsion may be obtained by any method.
The core-shell type acrylic urethane resin emulsion can be obtained as shown in the following (a) to (d).
(A) After reacting at least one organic diisocyanate (A) and at least one polycarbonate polyol (B), an acid diol is added to the poly (carbonate-urethane) prepolymer in which a carboxyl group is introduced. A polymer (A1) is obtained.
(B) An acrylic monomer (C) is added to the poly (carbonate-urethane) prepolymer (A1) to obtain a prepolymer / monomer mixture.
(C) A tertiary amine is added to the mixture to be dispersed in water, and then a radical initiator and a chain extender are added to obtain an aqueous dispersion.
(D) By heating the aqueous dispersion to polymerize the (C) acrylic monomer, an acrylic urethane resin emulsion having the (A1) as a shell component and the polymer (C) as a core is obtained. be able to.
In the polymerization in (d), a vinyl monomer may be added separately as necessary.
There is no restriction | limiting in particular as said vinyl-type monomer, According to the objective, it can select suitably, For example, butadiene, styrene, substituted styrene, vinyl acetate, vinyl butyrate, vinyl chloride, vinylidene chloride etc. are mentioned.

  There is no restriction | limiting in particular as said organic diisocyanate (A), According to the objective, it can select suitably, For example, an aliphatic, an alicyclic, an aliphatic aromatic, an aromatic etc. are mentioned, As a specific example, For example, ethylene diisocyanate, 1,6-hexamethylene diisocyanate, isophorone diisocyanate, cyclohexane-1,4-diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate, 2,6 -Toluene diisocyanate, 4,4'-diphenylmethane diisocyanate, 2,4'-diphenylmethane diisocyanate, polymethylene polyphenyl polyisocyanate, 1,5-naphthylene diisocyanate and the like.

  There is no restriction | limiting in particular as said acid diol, According to the objective, it can select suitably, For example, 2, 2- dimethylol propionic acid etc. are mentioned.

There is no restriction | limiting in particular as said polycarbonate polyol (B), Although it can select suitably according to the objective, It is preferable that it is a product obtained by making diol and a carbonate compound react.
The diol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include 1,3-propanediol, 2-methyl-1,3-propanediol, 1,4-butanediol, , 6-propanediol, diethylene glycol and the like.
There is no restriction | limiting in particular as said carbonate compound, According to the objective, it can select suitably, For example, ethylene carbonate, diphenyl carbonate, phosgene etc. are mentioned.

  There is no restriction | limiting in particular as said acrylic monomer (C), According to the objective, it can select suitably, For example, acrylic acid, methacrylic acid ester, etc. are mentioned. Of these, lower (1 to 6 carbon atoms) alkyl esters of acrylic acid and methacrylic acid are preferred.

  The tertiary amine is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include triethylamine and dimethylethanolamine. These may be used individually by 1 type and may use 2 or more types together.

The radical initiator is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 2,2′-azobis (2,4-dimethylpentanenitrile), 2,2′-azobis (2- And azo type compounds such as methylpropanenitrile).
There is no restriction | limiting in particular as said chain extender, According to the objective, it can select suitably, For example, ethylenediamine, diethylenetriamine, triethylenetetramine etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  As the core-shell type acrylic urethane resin particles, those appropriately synthesized may be used, or commercially available products may be used. Examples of the commercially available product include an acrylic WEM series (WEM-200U, WEM-3000) manufactured by Taisei Fine Chemical Co., Ltd., as a resin emulsion dispersed in water.

--- Polyester resin particles--
By containing the polyester resin particles, the white ink can improve adhesion to the non-permeable recording medium, and in particular, can obtain extremely high adhesion to the polyester resin film.

  The weight average molecular weight of the polyester resin particles is preferably 30,000 or less from the viewpoint of easy control of the dispersed particle diameter. The weight average molecular weight can be measured using, for example, gel permeation chromatography (GPC).

  As a glass transition temperature (Tg) of the said polyester resin particle, 70 degrees C or less is preferable. When the glass transition temperature is 70 ° C. or lower, the breaking elongation (breaking elongation) can be increased, and the abrasion resistance can be improved. Further, when printing on a recording medium such as an inkjet dedicated paper having a coating layer, it becomes easy to adhere to the recording medium.

  Commercially available products can be used as the polyester resin particles having a glass transition temperature (Tg) of 70 ° C. or less. Examples of the commercially available products include Vylonal MD-2000 (manufactured by Toyobo Co., Ltd.), Plus Coat Z-221 ( (Manufactured by Kenji Chemical Industry Co., Ltd.).

--Polyolefin-modified polyester urethane resin particles--
By containing the polyolefin-modified polyester urethane resin particles, the white ink can improve the adhesion to the non-permeable recording medium, and in particular, can obtain extremely high adhesion to the polypropylene resin film.
The polyolefin-modified polyester urethane resin means a polyester urethane resin having a polyolefin skeleton in the main chain or side chain. The polyester urethane resin can be obtained, for example, by reacting polyester polyol and polyisocyanate.

As the polyolefin-modified polyester urethane resin particles, those appropriately synthesized may be used, or commercially available products may be used.
Examples of the commercially available products include Superflex 210 (Daiichi Kogyo Seiyaku Co., Ltd.).

There is no restriction | limiting in particular as a synthesis method of the said polyolefin modified polyester urethane resin, According to the objective, it can select suitably, For example, the method of Unexamined-Japanese-Patent No. 10-72562 etc. are mentioned.
That is, an acid of a polyurethane resin comprising a polyolefin-modified polyester polyol, another polyester polyol, a polyisocyanate compound, a compound having an acidic group and at least two active hydrogen-containing groups in the molecule, and a chain extender. For example, the group may be neutralized with ammonia and / or an organic amine and dispersed in an aqueous medium.

--- Polyolefin-modified polyester polyol ---
The polyolefin-modified polyester polyol means a polyolefin-modified polyester containing hydroxyl groups at both ends and / or side chains of the molecule.
The method for producing the polyolefin-modified polyester polyol is not particularly limited and may be appropriately selected depending on the purpose. For example, dehydration polycondensation or transesterification reaction between a compound that imparts an olefin group and a dicarboxylic acid is performed. And a method for obtaining a polyolefin-modified polyester having a terminal hydroxyl group.

  Examples of the compound that imparts the olefin group include carbon numbers such as 1,2-hexanediol, 1,2-octanediol, 1,2-decanediol, 1,2-dodecanediol, 1,2-octadecanediol, and the like. 5 or more and 42 or less 1,2-alkanediol; glycerol monohexyl ether, glycerol monooctyl ether, glycerol mono-2-ethylhexyl ether, glycerol monodecyl ether, glycerol monododecyl ether, glycerol monooctadecyl ether, etc. 6 or more carbon atoms 43 or less glycerin monoalkyl ether; glycerin hexanoic acid monoester, glycerin octanoic acid monoester, glycerin-2-ethylhexanoic acid monoester, glycerin decanoic acid monoester, glycerin dodecanoic acid monoe Ether, and the number 7 or 44 or less glycerol fatty acid monoester carbon atoms such as glycerin octadecanoic acid monomethyl ester. These may be used individually by 1 type and may use 2 or more types together.

  Examples of the dicarboxylic acids include aliphatic dicarboxylic acids having 4 to 10 carbon atoms (for example, adipic acid, succinic acid, sebacic acid, azelaic acid, fumaric acid, maleic acid, etc.) or ester-forming derivatives thereof, aromatics Examples thereof include dicarboxylic acids (for example, phthalic acid, terephthalic acid, isophthalic acid, etc.) or ester-forming derivatives thereof. These may be used individually by 1 type and may use 2 or more types together.

--- Other polyester polyols ---
Examples of the other polyester polyols include those obtained by esterifying low molecular weight polyols and polycarboxylic acids, polyesters obtained by ring-opening polymerization reaction of cyclic ester compounds such as ε-caprolactone, These copolyesters can be mentioned.

Examples of the low molecular weight polyol include ethylene glycol and propylene glycol.
Examples of the polycarboxylic acid include succinic acid, adipic acid, sebacic acid, dodecanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, and anhydrides or ester-forming derivatives thereof.

--- Polyisocyanate compound ---
The polyisocyanate compound is not particularly limited and may be appropriately selected depending on the intended purpose. For example, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, 2,4-tolylene diisocyanate (TDI), 2,6-tolylene diisocyanate, 4,4'-diphenylenemethane diisocyanate (MDI), 2,4-diphenylmethane diisocyanate, 4,4'-diisocyanatobiphenyl, 3,3'-dimethyl-4,4'- Aromatic poly, such as diisocyanatobiphenyl, 3,3′-dimethyl-4,4′-diisocyanatodiphenylmethane, 1,5-naphthylene diisocyanate, m-isocyanatophenylsulfonyl isocyanate, p-isocyanatophenylsulfonyl isocyanate Isocyanate compound; Eth Diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 1,6,11-undecane triisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl carbonate Aliphatic polyisocyanate compounds such as proate, bis (2-isocyanatoethyl) fumarate, bis (2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate; isophorone diisocyanate ( IPDI), 4,4′-dicyclohexylmethane diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TD) ), Alicyclic polycyanate compounds such as bis (2-isocyanatoethyl) -4-dichlorohexene-1,2-dicarboxylate, 2,5-norbornane diisocyanate, 2,6-norbornane diisocyanate, and the like. It is done. These may be used individually by 1 type and may use 2 or more types together. Among these, aliphatic or alicyclic diisocyanates are preferable from the viewpoint of requiring a coating film having long-term weather resistance.

--- A compound having an acidic group and at least two active hydrogen-containing groups in the molecule ---
Examples of the compound having an acidic group and at least two active hydrogen-containing groups in the molecule include glycolic acid, tartaric acid, 4,6-dihydroxyisophthalic acid, α, α-dimethylolpropionic acid, α, α- Hydroxy acids such as dimethylol butyric acid, α, α-dimethylol nonanoic acid, and carboxyl group-containing polycaprolactone diol obtained by addition polymerization of caprolactone monomers thereto, hydroxysulfonic acids such as 1,7-dihydroxynaphthalenesulfonic acid, And aminosulfonic acid such as 4-diaminobenzenesulfonic acid. These may be used individually by 1 type and may use 2 or more types together. Among these, compounds having two hydroxyl groups and one carboxyl group in the molecule; α, α-dimethylolpropionic acid, α, α-dimethylolbutyric acid, or carboxyl obtained by addition polymerization of these with caprolactone monomer Group-containing polycaprolactone diols are preferred.

There is no restriction | limiting in particular as a manufacturing method of the said polyolefin modified polyester urethane resin particle, According to the objective, it can select suitably, For example, the following method is mentioned.
First, in the absence of a solvent or in the presence of an organic solvent, the two polyols and the polyisocyanate are reacted at an equivalent ratio in which an isocyanate group becomes excessive to produce an isocyanate-terminated urethane prepolymer.

  The ratio of the polyester polyol and the polyolefin-modified polyol at this time is preferably such that the part derived from the polyol in the prepolymer has a molecular weight ratio of 60:40 or more, more preferably 80:20 or more, and particularly preferably 90:10 or more. preferable.

  Next, the anionic group in the isocyanate-terminated urethane prepolymer is neutralized with the neutralizing agent as necessary, and then reacted with a chain extender, and finally the organic solvent in the system is removed as necessary. Can be obtained.

  Examples of usable organic solvents include ketones such as acetone and methyl ethyl ketone, ethers such as tetrahydrofuran and dioxane, acetates such as ethyl acetate and butyl acetate, nitriles such as acetonitrile, dimethylformamide, and N-methyl. Examples include amides such as pyrrolidone and N-ethylpyrrolidone. These may be used individually by 1 type and may use 2 or more types together.

--- Chain extender ---
Examples of the chain extender include polyamines and other active hydrogen atom-containing compounds.
Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4′-dicyclohexylmethanediamine, and 1,4-cyclohexane. Diamines such as diamine, polyamines such as diethylenetriamine, dipropylenetriamine and triethylenetetramine, hydrazines such as hydrazine, N, N′-dimethylhydrazine, 1,6-hexamethylenebishydrazine, succinic dihydrazide, adipic acid dihydrazide And dihydrazides such as glutaric acid dihydrazide, sebacic acid dihydrazide, and isophthalic acid dihydrazide.

  Examples of the other active hydrogen group-containing compounds include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, hexamethylene glycol, Glycols such as saccharose, methylene glycol, glycerin, sorbitol; phenols such as bisphenol A, 4,4′-dihydroxydiphenyl, 4,4′-dihydroxydiphenyl ether, 4,4′-dihydroxydiphenyl sulfone, hydrogenated bisphenol A, hydroquinone Kind; water etc. are mentioned. These may be used alone or in combination of two or more as long as the storage stability of the ink is not lowered.

[Method for dispersing resin particles]
If necessary, the resin particles may contain a dispersant such as a surfactant. From the viewpoint of easily obtaining an ink having a better coating film performance, a so-called self-emulsifying resin emulsion is used. preferable.

  The self-emulsifying resin emulsion preferably contains an anionic group having an acid value of 5 mgKOH / g or more and 100 mgKOH / g or less from the viewpoint of water dispersibility, and imparts abrasion resistance and chemical resistance. From 5 mgKOH / g to 50 mgKOH / g, an anionic group is more preferable.

  As the anionic group, for example, a carboxyl group or a sulfonic acid group can be used to obtain good water dispersion stability. In order to introduce these anionic groups into the resin, these anionic groups have these anionic groups. Monomers may be used.

  In the white ink, since the resin particles are dispersed in water, a surfactant can be used as necessary. Examples thereof include nonionic surfactants and anionic surfactants. These may be used individually by 1 type and may use 2 or more types together. Among these, a nonionic surfactant is preferable from the viewpoint of water resistance of the dispersed fat particles.

  The nonionic surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. For example, polyoxyethylene alkyl ether, polyoxyethylene alkylene alkyl ether, polyoxyethylene derivative, polyoxyethylene fatty acid ester , Polyoxyethylene polyhydric alcohol fatty acid ester, polyoxyethylene propylene polyol, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene hydrogenated castor oil, polyoxyalkylene polycyclic phenyl ether, polyoxyethylene alkylamine, alkyl alkanolamide And polyalkylene glycol (meth) acrylate. These may be used individually by 1 type and may use 2 or more types together. Among these, polyoxyethylene alkyl ether, polyoxyethylene fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and polyoxyethylene alkylamine are preferable.

  The anionic surfactant is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alkyl sulfate esters, polyoxyethylene alkyl ether sulfates, alkyl benzene sulfonates, and α-olefin sulfonic acids. Salt, methyl taurate, sulfosuccinate, ether sulfonate, ether carboxylate, fatty acid salt, naphthalenesulfonic acid formalin condensate, alkylamine salt, quaternary ammonium salt, alkylbetaine, alkylamine oxide, etc. . These may be used individually by 1 type and may use 2 or more types together. Among these, polyoxyethylene alkyl ether sulfate and sulfosuccinate are preferable.

  As content of the said surfactant, 0.1 mass% or more and 30 mass% or less are preferable with respect to the resin particle whole quantity, and 5 mass% or more and 20 mass% or less are more preferable. When the content is 30% by mass or less, an excessive amount of emulsifier necessary for forming resin particles does not significantly reduce adhesion and water resistance, and when a dry film is formed. It is possible to prevent the plastic effect and bleeding phenomenon from being caused, and to suppress the occurrence of blocking.

Moreover, a basic substance can be added as needed for the purpose of neutralizing the acidic component in a resin particle, and making it disperse | distribute to water.
The basic substance is not particularly limited and may be appropriately selected depending on the intended purpose. Sodium hydroxide, potassium hydroxide, ammonia, methylamine, propylamine, hexylamine, octylamine, ethanolamine, propanolamine , Diethanolamine, N-methyldiethanolamine, dimethylamine, diethylamine, triethylamine, N, N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-propanol, morpholine, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together. Among these, ammonia, triethylamine, 2-amino-2-methyl-1-propanol, and morpholine are preferable.
The content of the basic substance can be arbitrarily prepared according to the amount of the acidic component of the resin particles.

The resin particles are preferably used as a resin emulsion, and the resin emulsion may be obtained by any method.
As the resin emulsion, if necessary, a water-soluble organic solvent, an antiseptic, a leveling agent, an antioxidant, a light stabilizer, an ultraviolet absorber and the like can be blended.

<Organic solvent>
There is no restriction | limiting in particular as said organic solvent, According to the objective, it can select suitably, A water-soluble organic solvent etc. are mentioned. The water solubility in the water-soluble organic solvent means that, for example, 5 g or more is dissolved in 100 g of water at 25 ° C.

  Examples of the water-soluble organic solvent include ethylene glycol, diethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-butanediol, 2,3-butanediol, 3-methyl-1,3-butanediol, 3-methoxy-3-methyl-1-butanol, triethylene glycol, polyethylene glycol, polypropylene glycol, 1,5-pentanediol, 2-methyl-2,4-pentanediol 1,6-hexanediol, glycerin, 1,2,6-hexanetriol, 2-ethyl-1,3-hexanediol, ethyl 1,2,4-butanetriol, 1,2,3-butanetriol, petri Polyhydric alcohols such as all, ethylene glycol monoethyl ether, Polyethylene alcohol alkyl ethers such as lenglycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, tetraethylene glycol monomethyl ether, propylene glycol monoethyl ether, dipropylene glycol monomethyl ether, ethylene glycol monophenyl ether, Polyhydric alcohol aryl ethers such as ethylene glycol monobenzyl ether, 2-pyrrolidone, N-methyl-2-pyrrolidone, N-hydroxyethyl-2-pyrrolidone, 1,3-dimethylimidazolidinone, ε-caprolactam, γ- Nitrogen-containing heterocyclic compounds such as butyrolactone, formamide, N-methylformamide, N, N-dimethylphenol Amides such as Muamido, monoethanolamine, diethanolamine, amines such as triethylamine, dimethyl sulfoxide, sulfolane, sulfur-containing compounds such as thiodiethanol, propylene carbonate, and the like ethylene carbonate. These may be used individually by 1 type and may use 2 or more types together.

  There is no restriction | limiting in particular as said organic solvent, Although it can select suitably according to the objective, It is preferable that 3-methoxy-3-methyl- 1-butanol is included. When the 3-methoxy-3-methyl-1-butanol is contained, although the reason is not clear, the abrasion resistance of the ink coating film can be improved.

  The content of 3-methoxy-3-methyl-1-butanol is preferably 6% by mass or less and more preferably 5% by mass or less based on the total amount of white ink from the viewpoint of abrasion resistance.

  The content of the organic solvent is preferably 10% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 60% by mass or less, based on the total amount of white ink, from the viewpoints of ink drying properties and ejection reliability. preferable.

<Color material>
As the color material, a material having a whiteness measured in accordance with ISO-2469 (JIS-8148) of an image recorded using white ink containing the color material may be 70 or more.

There is no restriction | limiting in particular as said coloring material, According to the objective, it can select suitably, For example, dye, a pigment, etc. are mentioned.
Examples of the pigment include metal oxides.
Examples of the metal oxide include titanium oxide, iron oxide, tin oxide, zirconium oxide, and iron titanate (a composite oxide of iron and titanium). These may be used individually by 1 type and may use 2 or more types together.

The number average particle diameter of the pigment is not particularly limited and may be appropriately selected depending on the intended purpose, but the maximum frequency is preferably 20 nm or more and 150 nm or less in terms of the maximum number. When the number average particle size is 20 nm or more, dispersion operation and classification operation are facilitated, and when it is 150 nm or less, not only pigment dispersion stability as ink is improved, but also ejection stability is excellent. Image quality such as image density is also high, which is preferable.
The number average particle diameter can be measured using, for example, a particle size analyzer (Microtrac Model UPA9340, manufactured by Nikkiso Co., Ltd.).

In order to disperse the pigment in the ink, a method of introducing a hydrophilic functional group into the pigment to form a self-dispersing pigment, a method of dispersing the pigment surface by coating with a resin, a method of dispersing using a dispersant, Etc.
Examples of a method for introducing a hydrophilic functional group into a pigment to form a self-dispersing pigment include a self-dispersing pigment that can be dispersed in water by adding a functional group such as a sulfone group or a carboxyl group to the pigment (for example, carbon). Can be used.
As a method for coating the surface of the pigment with a resin and dispersing it, a method in which the pigment is included in microcapsules and can be dispersed in water can be used. This can be paraphrased as a resin-coated pigment. In this case, it is not necessary that all pigments blended in the ink are coated with a resin, and within a range where the effects of the present invention are not impaired, uncoated pigments and partially coated pigments are dispersed in the ink. It may be.
Examples of the method of dispersing using a dispersant include a method of dispersing using a known low-molecular type dispersant or high-molecular type dispersant represented by a surfactant.
As the dispersant, for example, an anionic surfactant, a cationic surfactant, an amphoteric surfactant, a nonionic surfactant, or the like can be used depending on the pigment.
RT-100 (nonionic surfactant) manufactured by Takemoto Yushi Co., Ltd. and naphthalenesulfonic acid Na 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.

<Pigment dispersion>
An ink can be obtained by mixing a material such as water or an organic solvent with a pigment. Further, it is also possible to produce an ink by mixing a pigment, other water, a dispersant, and the like into a pigment dispersion and mixing a material such as water or an organic solvent.
The pigment dispersion is obtained by dispersing water, a pigment, a pigment dispersant, and other components as required, and adjusting the particle size. For dispersion, a disperser is preferably used.
The particle size of the pigment in the pigment dispersion is not particularly limited, but the maximum frequency is 20 nm or more in terms of maximum number because the pigment dispersion stability is good and the image quality such as ejection stability and image density is also high. 500 nm or less is preferable and 20 nm or more and 150 nm or less are more preferable. The particle size of the pigment can be measured using a particle size analyzer (Nanotrack Wave-UT151, manufactured by Microtrack Bell Co., Ltd.).
The content of the pigment in the pigment dispersion is not particularly limited and may be appropriately selected depending on the intended purpose. However, from the viewpoint of obtaining good ejection stability and increasing the image density, 0.1% by mass. % To 50% by mass is preferable, and 0.1% to 30% by mass is more preferable.
The pigment dispersion is preferably degassed by filtering coarse particles with a filter, a centrifugal separator or the like, if necessary.

  The content of the color material 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 improvement in image density, good fixability and ejection stability. It is as follows.

  The content of the pigment is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.1% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 10% by mass or less with respect to the total amount of the ink. Particularly preferred. When the content is 0.1% by mass or more and 15% by mass or less, image density, fixability, and ejection stability can be improved.

<Water>
There is no restriction | limiting in particular as said water, According to the objective, it can select suitably, For example, pure water, such as ion-exchange water, ultrafiltration water, reverse osmosis water, distilled water, ultrapure water, etc. are mentioned. . These may be used individually by 1 type and may use 2 or more types together.

  The content of the water is preferably 15% by mass or more and 60% by mass or less, and more preferably 20% by mass or more and 40% by mass or less with respect to the total amount of the white ink. When the content is 15% by mass or more, high viscosity can be prevented and ejection stability can be improved. When the content is 60% by mass or less, wettability to a non-permeable recording medium is preferable. Image quality can be improved.

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, an antirust agent, a pH adjuster, and the like may be added to the ink.

<Surfactant>
As the surfactant, any of silicone surfactants, fluorine surfactants, amphoteric surfactants, nonionic surfactants and anionic surfactants can be used.
There is no restriction | limiting in particular in silicone type surfactant, According to the objective, it can select suitably. Among them, those that do not decompose even at high pH are preferable, and examples thereof include side chain modified polydimethylsiloxane, both terminal modified polydimethylsiloxane, one terminal modified polydimethylsiloxane, and side chain both terminal modified polydimethylsiloxane. Those having an oxyethylene group or a polyoxyethylene polyoxypropylene group are particularly preferred because they exhibit good properties as an aqueous surfactant. In addition, as the silicone surfactant, a polyether-modified silicone surfactant can be used, and examples thereof include a compound in which a polyalkylene oxide structure is introduced into the side chain of the Si portion of dimethylsiloxane.
Examples of the fluorosurfactant include a perfluoroalkyl sulfonic acid compound, a perfluoroalkyl carboxylic acid compound, a perfluoroalkyl phosphate compound, a perfluoroalkyl ethylene oxide adduct, and a perfluoroalkyl ether group in the side chain. Polyoxyalkylene ether polymer compounds are particularly preferred because of their low foaming properties. Examples of the perfluoroalkyl sulfonic acid compound include perfluoroalkyl sulfonic acid, perfluoroalkyl sulfonate, and the like. Examples of the perfluoroalkylcarboxylic acid compound include perfluoroalkylcarboxylic acid and perfluoroalkylcarboxylate. Examples of the polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain include a sulfate ester salt of a polyoxyalkylene ether polymer having a perfluoroalkyl ether group in the side chain and a perfluoroalkyl ether group in the side chain. Examples thereof include salts of polyoxyalkylene ether polymers. As counter ions of salts in these fluorosurfactants, Li, Na, K, NH ₄ , NH ₃ CH ₂ CH ₂ OH, NH ₂ (CH ₂ CH ₂ OH) ₂ , NH (CH ₂ CH ₂ OH) ₃ etc. are mentioned.
Examples of amphoteric surfactants include lauryl aminopropionate, lauryl dimethyl betaine, stearyl dimethyl betaine, and lauryl dihydroxyethyl betaine.
Nonionic surfactants include, for example, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ester, polyoxyethylene alkylamine, polyoxyethylene alkylamide, polyoxyethylene propylene block polymer, sorbitan fatty acid ester, polyoxyethylene sorbitan Examples include fatty acid esters and ethylene oxide adducts of acetylene alcohol.
Examples of the anionic surfactant include polyoxyethylene alkyl ether acetate, dodecylbenzene sulfonate, laurate, polyoxyethylene alkyl ether sulfate salt, and the like.
These may be used alone or in combination of two or more.

As the fluorine-based surfactant, a fluorine-substituted compound having 2 to 16 carbon atoms is preferable, and a fluorine-substituted compound having 4 to 16 carbon atoms is more preferable.
Examples of the fluorosurfactant include perfluoroalkyl phosphate compounds, perfluoroalkylethylene oxide adducts, and polyoxyalkylene ether polymer compounds having a perfluoroalkyl ether group in the side chain.
Among these, a polyoxyalkylene ether polymer compound having a perfluoroalkyl ether group in the side chain is preferable because of its low foaming property, and in particular, fluorine-based compounds represented by the general formulas (F-1) and (F-2) A surfactant is preferred.
[General Formula (F-2)]
In the compound represented by the general formula (F-1), m is preferably an integer of 0 to 10 and n is preferably an integer of 0 to 40 in order to impart water solubility.
[General Formula (F-2)]
_{C n F 2n + 1- CH 2} CH (OH) CH 2 -O- (CH 2 CH 2 O) a -Y
In the compound represented by the general formula (F-2), Y is H, or CnF _{2n + 1} , n is an integer of 1 to 6, or CH ₂ CH (OH) CH ₂ —CnF _{2n + 1,} where n is 4 to 6. An integer, or CpH _{2p + 1} , p is an integer of 1-19. a is an integer of 4-14.
A commercial item may be used as said fluorosurfactant.
As this commercial item, for example, Surflon S-111, S-112, S-113, S-121, S-131, S-132, S-141, S-145 (all manufactured by Asahi Glass Co., Ltd.); Fullrad FC-93, FC-95, FC-98, FC-129, FC-135, FC-170C, FC-430, FC-431 (all manufactured by Sumitomo 3M Limited); Megafac F-470, F -1405, F-474 (all manufactured by DIC Corporation); Zonyl TBS, FSP, FSA, FSN-100, FSN, FSO-100, FSO, FS-300, UR, Capstone FS-30, FS-31, FS-3100, FS-34, FS-35 (all manufactured by Chemours); FT-110, FT-250, FT-251 FT-400S, FT-150, FT-400SW (all manufactured by Neos Co., Ltd.), Polyfox PF-136A, PF-156A, PF-151N, PF-154, PF-159 (Omnova), Unidyne DSN-403N (manufactured by Daikin Industries, Ltd.) and the like. Among these, good print quality, particularly color development, penetrability to paper, wettability, and leveling are remarkably improved, and manufactured by Chemours. FS-3100, FS-34, FS-300, FT-110, FT-250, FT-251, FT-400S, FT-150, FT-400SW manufactured by Neos Co., Ltd. Polyfox PF-151N manufactured by Omniva And Unidyne DSN-403N manufactured by Daikin Industries, Ltd. is particularly preferable.

  There is no restriction | limiting in particular as content of surfactant in an ink, Although it can select suitably according to the objective, From the point which is excellent in wettability and discharge stability, and image quality improves, it is 0.001 mass. % To 5% by mass is preferable, and 0.05% to 5% by mass is more preferable.

<Antifoaming agent>
There is no restriction | limiting in particular as an antifoamer, For example, a silicone type antifoamer, a polyether type | system | group antifoamer, a fatty-acid ester type | system | group antifoamer etc. are mentioned. These may be used alone or in combination of two or more. Among these, a silicone type antifoaming agent is preferable from the viewpoint of excellent foam breaking effect.

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

<Rust preventive>
There is no restriction | limiting in particular as a rust preventive agent, For example, acidic sulfite, sodium thiosulfate, etc. are mentioned.

<PH adjuster>
The pH adjuster is not particularly limited as long as the pH can be adjusted to 7 or more, and examples thereof include amines such as diethanolamine and triethanolamine.

There is no restriction | limiting in particular as a physical property of an ink, According to the objective, it can select suitably, For example, it is preferable that a viscosity, surface tension, pH, etc. are the following ranges.
The viscosity at 25 ° C. of the ink is preferably 5 mPa · s or more and 30 mPa · s or less, preferably 5 mPa · s or more and 25 mPa · s or less from the viewpoint of improving the printing density and character quality and obtaining good discharge properties. More preferred. Here, for the viscosity, for example, a rotary viscometer (RE-80L manufactured by Toki Sangyo Co., Ltd.) can be used. Measurement conditions are 25 ° C., standard cone rotor (1 ° 34 ′ × R24), sample liquid amount 1.2 mL, rotation speed 50 rpm, and measurement is possible for 3 minutes.
The surface tension of the ink is preferably 35 mN / m or less and more preferably 32 mN / m or less at 25 ° C. from the viewpoint that the ink is suitably leveled on the recording medium and the drying time of the ink is shortened.
The pH of the ink is preferably 7 to 12 and more preferably 8 to 11 from the viewpoint of preventing corrosion of the metal member in contact with the liquid.

[Method for producing white ink]
As the method for producing the white ink, for example, the water, the organic solvent, the coloring material, the polyurethane resin particles, the other resin particles, and, if necessary, the additive are produced by stirring and mixing. can do. As the stirring and mixing, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, a stirrer using a normal stirrer blade, a magnetic stirrer, a high-speed disperser, or the like can be used.

<Non-white ink>
The non-white ink contains water, an organic solvent, and styrene acrylic resin particles, preferably contains a coloring material, and further contains other components as necessary.
Examples of the non-white ink include color ink, black ink, gray ink, clear ink, and metallic ink. These may be used individually by 1 type and may use 2 or more types together.
The clear ink means an ink mainly containing resin particles, an organic solvent, and water without including a color material.
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. Can be mentioned.

-Styrene acrylic resin particles-
The styrene acrylic resin particles contained in the non-white ink are preferably the same as the styrene acrylic resin particles contained in the white ink. When the styrene acrylic resin particles contained in the white ink and the styrene acrylic resin particles contained in the non-white ink are the same, the adhesion between the coating films of each color is increased, and the coating film is at the boundary of each color. It can prevent peeling.

-Organic solvent-
As the organic solvent, the same organic solvent as in the white ink can be used.
The organic solvent contained in the non-white ink is preferably the same as the organic solvent contained in the white ink. When the organic solvent contained in the white ink and the organic solvent contained in the non-white ink are the same, the adhesion between the coating films of the respective colors can be improved.

-Color material-
The color material used for 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, and examples thereof include dyes and pigments. These may be used alone or in combination of two or more. Among these, a pigment is preferable.
Examples of the pigment include inorganic pigments and organic pigments.

  As the inorganic pigment, for example, in addition to titanium oxide, iron oxide, calcium carbonate, barium sulfate, aluminum hydroxide, barium yellow, cadmium red, and chrome yellow, it is manufactured by a known method such as a contact method, a furnace method, or a thermal method. And carbon black. These may be used individually by 1 type and may use 2 or more types together.

Examples of the organic pigment include azo pigments (for example, azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments). , Quinacridone pigments, dioxazine pigments, indigo pigments, thioindigo pigments, isoindolinone pigments, quinofullerone pigments, etc.), dye chelates (eg basic dye chelates, acidic dye chelates), nitro pigments, nitroso pigments, aniline black, etc. Is mentioned. These may be used individually by 1 type and may use 2 or more types together.
In addition, use of hollow resin particles and inorganic hollow particles is also possible.
Of these pigments, those having good affinity with the solvent are preferably used.

  As the pigment, for black, for example, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black, channel black, copper, iron (CI pigment black 11) And organic pigments such as aniline black (CI Pigment Black 1). 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 (Bengara), 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; 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; I. Acid Red 52, 80, 82, 249, 254, 289; I. Acid Blue 9, 45, 249; C.I. I. Acid Black 1, 2, 24, 94; C.I. I. Food black 1, 2; I. Direct yellow 1, 12, 24, 33, 50, 55, 58, 86, 132, 142, 144, 173; I. Direct Red 1, 4, 9, 80, 81, 225, 227; I. Direct blue 1, 2, 15, 71, 86, 87, 98, 165, 199, 202; I. Directed Black 19, 38, 51, 71, 154, 168, 171, 195; I. Reactive red 14, 32, 55, 79, 249; I. Reactive black 3, 4, 35 etc. are mentioned. These may be used individually by 1 type and may use 2 or more types together.

  The color material used for the metallic ink is a fine powder obtained by finely pulverizing a simple metal, an alloy, or a metal compound, and more specifically, aluminum, silver, gold, nickel, chromium, tin, zinc, indium. Any one or more of single metals selected from titanium, silicone, copper, and platinum, or alloys obtained by combining these groups of metals, or oxides of these groups of single metals or alloys, It is obtained by pulverizing one or more of nitride, sulfide, or carbide.

As a method of dispersing the pigment in the ink, a method similar to the method of dispersing the pigment in the white ink in the ink can be used.
Further, the pigment can be made into a pigment dispersion in the same manner as the pigment in the white ink.

  The content of the color material 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 improvement in image density, good fixability and ejection stability. It is as follows.

  The content of the pigment is preferably 0.1% by mass or more and 15% by mass or less, more preferably 0.1% by mass or more and 10% by mass or less, and more preferably 1% by mass or more and 10% by mass or less with respect to the total amount of the ink. Particularly preferred. When the content is 0.1% by mass or more and 15% by mass or less, image density, fixability, and ejection stability can be improved.

  As the water, the same water as the water in the white ink can be used.

<Additives>
If necessary, a surfactant, an antifoaming agent, an antiseptic / antifungal agent, an antirust agent, a pH adjuster, and the like may be added to the ink.
Examples of the surfactant, the antifoaming agent, the antiseptic / antifungal agent, the rustproofing agent, and the pH adjuster include the surfactant, the antifoaming agent, and the antiseptic / antifungal agent in the additive of the white ink. The same agents as the agent, the rust inhibitor, and the pH adjuster can be used.

  The physical properties of the non-white ink are not particularly limited, and the viscosity, surface tension, pH, and the like can be appropriately selected according to the purpose, but the same as the viscosity, surface tension, and pH of the white ink. can do.

<Recording medium>
The recording medium is not particularly limited and can be appropriately selected depending on the purpose. For example, plain paper, glossy paper, special paper, cloth, and the like can be used, but an impermeable recording medium is used. Can also form a good image. Moreover, it is not restricted to what is used as a general recording medium, Construction materials, such as a wallpaper and a flooring, Cloths, such as clothing for T-shirts, textiles, leather, etc. can be used suitably. Furthermore, ceramics, glass, metal, or the like can be used by adjusting the configuration of the path for conveying the recording medium.
The non-permeable recording medium is a recording medium having a surface with low water permeability and absorbency, including a material that does not open to the outside even if there are many cavities inside, more quantitatively. In the Bristow method, the recording medium has a water absorption amount of 10 mL / m ² or less from the start of contact to 30 msec ^1/2 .
Examples of the non-permeable recording medium include a vinyl chloride resin film, a polyethylene resin terephthalate (PET) film, an acrylic resin film, a polyester resin film, a polyethylene resin film, a polypropylene resin film, and a plastic film such as a polycarbonate resin film. It can be preferably used.
Conventionally, the vinyl chloride resin film has been widely used, but in recent years, dechlorinated vinyl materials have come to be used from an environmental point of view, PET film, acrylic resin film, polyester resin film, polyethylene resin film, polypropylene resin A transparent film such as a film is used.
Among these, high adhesiveness can be obtained with respect to an acrylic resin film, a polyester film, a polyethylene resin film, and a polypropylene resin film.

[Method for producing non-white ink]
The non-white ink can be produced, for example, by stirring and mixing the water, the organic solvent, the polyurethane resin particles, and, if necessary, the additive. As the stirring and mixing, for example, a sand mill, a homogenizer, a ball mill, a paint shaker, an ultrasonic disperser, a stirrer using a normal stirrer blade, a magnetic stirrer, a high-speed disperser, or the like can be used.

<Ink container>
The ink container contains each ink in the ink set of the present invention in the container.
The ink storage container is configured to store the ink in a container and further include other members appropriately selected as necessary.

  The container is not particularly limited, and its shape, structure, size, material and the like can be appropriately selected according to the purpose. For example, an ink bag formed of an aluminum laminate film, a resin film, etc. What has at least etc. is mentioned.

<Recording apparatus and recording method>
The ink of the present invention can be suitably used for various recording apparatuses using an ink jet recording method, such as a printer, a facsimile apparatus, a copying apparatus, a printer / fax / copier complex machine, and a three-dimensional modeling apparatus.
In the present invention, the recording apparatus and the recording method are an apparatus capable of ejecting ink, various treatment liquids, and the like to a recording medium, and a method of performing recording using the apparatus. The recording medium means a medium on which ink or various processing liquids can be temporarily attached.
The recording apparatus can include not only a head portion that ejects ink but also means for feeding, transporting, and discharging a recording medium, and other devices called pre-processing devices and post-processing devices. .
The recording apparatus and the recording method may include a heating unit used in the heating step and a drying unit used in the drying step. The heating means and the drying means include, for example, a means for heating and drying the printing surface and the back surface of the recording medium. Although it does not specifically limit as a heating means and a drying means, For example, a warm air heater and an infrared heater can be used. Heating and drying can be performed before printing, during printing, after printing, and the like.
Further, the recording apparatus and the recording method are not limited to those in which significant images such as characters and figures are visualized by ink. For example, what forms patterns, such as a geometric pattern, etc. includes what forms a three-dimensional image.
Further, the recording apparatus includes both a serial type apparatus that moves the ejection head and a line type apparatus that does not move the ejection head, unless otherwise specified.
Furthermore, this recording apparatus can use not only a desktop type but also a wide recording apparatus that can print on an A0 size recording medium, for example, a continuous paper wound up in a roll shape as a recording medium. Also included are continuous paper printers.
An example of the recording apparatus will be described with reference to FIGS. FIG. 1 is a perspective view of the apparatus. FIG. 2 is an explanatory perspective view of the main tank. An image forming apparatus 400 as an example of a recording apparatus is a serial type image forming apparatus. A mechanism unit 420 is provided in the exterior 401 of the image forming apparatus 400. Each ink storage portion 411 of the main tank 410 (410k, 410c, 410m, 410y) for each color of black (K), cyan (C), magenta (M), yellow (Y) is packaged, for example, an aluminum laminate film It is formed by a member. The ink storage unit 411 is stored in, for example, a plastic container case 414. As a result, 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 inner 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. Thus, the ink discharge ports 413 of the main tank 410 and the discharge heads 434 for the respective colors communicate with each other via the supply tubes 436 for the respective colors, and ink can be discharged from the discharge heads 434 to the recording medium.

  In the recording apparatus and the recording method, the case where black (K), cyan (C), magenta (M), and yellow (Y) are used has been described, and the white ink and the non-white ink are included. When printing using an ink set, white ink may be used instead of black (K), cyan (C), magenta (M), or yellow (Y), or black (K), cyan. In addition to (C), magenta (M), and yellow (Y), white ink may be used.

  The ink in the ink set of the present invention is not particularly limited with respect to the printing method, and can be widely used. Besides the printing method, for example, blade coating method, gravure coating method, gravure offset coating method, bar coating method, roll coating method, knife coating method, air knife coating method, comma coating method, U comma coating method, AKKU coating method , Smoothing coating method, micro gravure coating method, reverse roll coating method, 4 to 5 roll coating method, dip coating method, curtain coating method, slide coating method, die coating method, spray coating method and the like.

As a printing method of the present invention, a white ink application step for applying the white ink to a non-permeable recording medium, and an image is formed by applying the non-white ink on a surface to which the white ink is applied. An image forming process, and further include other processes as necessary.
Further, the printing apparatus of the present invention includes: an ink storage unit that stores the white ink and the non-white ink; and an ink discharge head that applies a stimulus to the white ink and the non-white ink and causes the ink to fly. And other means as necessary.

  As the ink discharge head, a piezoelectric element is used as a pressure generating means for pressurizing ink in the ink flow path, and a diaphragm that forms the wall surface of the ink flow path is deformed to change the volume in the ink flow path to thereby drop ink droplets. A so-called piezo-type one that discharges (refer to Japanese Patent Laid-Open No. 2-51734), a so-called thermal type that generates bubbles by heating ink in an ink flow path using a heating resistor (Japanese Patent Laid-Open No. 61-59911). In other words, the diaphragm and the electrode forming the wall surface of the ink flow path are opposed to each other, and the diaphragm is deformed by an electrostatic force generated between the vibration plate and the electrode. Any case of an electrostatic type in which ink droplets are changed and discharged (see Japanese Patent Laid-Open No. 6-71882) is included.

  The stimulus can be generated by, for example, the stimulus generating means, and the stimulus is not particularly limited and can be appropriately selected according to the purpose. For example, heat (temperature), pressure, vibration, light Etc. These may be used individually by 1 type and may use 2 or more types together. Among these, heat and pressure are preferable.

  There is no particular limitation on the mode of the ink flying, and it varies depending on the type of the stimulus. For example, when the stimulus is “heat”, the ink in the ink ejection head corresponds to the recording signal. A method of applying thermal energy using, for example, a thermal head, generating bubbles in the ink by the thermal energy, and ejecting and ejecting the ink as droplets from the nozzle holes of the recording head by the pressure of the bubbles. Etc. In addition, when the stimulus is “pressure”, for example, by applying a voltage to a piezoelectric element bonded to a position called a pressure chamber in an ink flow path in the ink discharge head, the piezoelectric element bends and the pressure chamber And a method of ejecting and ejecting the ink as droplets from the nozzle holes of the ink ejection head.

  The size of the ink droplets to be ejected is preferably 3 pL or more and 40 pL or less, for example, and the ejection jet speed is preferably 5 m / s or more and 20 m / s or less, and the drive frequency is 1 kHz or more is preferable, and the resolution is preferably 300 dpi or more.

<Other processes and other means>
Examples of the other steps include a stimulus generation step and a control step.
Examples of the other means include stimulus generation means and control means.
Examples of the stimulus generating means include a heating device, a pressurizing device, a piezoelectric element, a vibration generating device, an ultrasonic oscillator, a light, and the like. Specifically, for example, a piezoelectric actuator such as a piezoelectric element, a heating resistor. Examples include a thermal actuator that uses a phase change caused by film boiling of a liquid using an electrothermal conversion element such as a shape memory alloy actuator that uses a metal phase change caused by a temperature change, and an electrostatic actuator that uses an electrostatic force.
The control means is not particularly limited as long as the movement of each means can be controlled, and can be appropriately selected according to the purpose. Examples thereof include devices such as a sequencer and a computer.

As an example of the embodiment, when white ink is applied to the entire surface of the recording medium, it is applied by a coating method other than the printing method, and when recording with a non-white ink, the printing method is used. Is possible.
As another embodiment, a recording method using both a white ink and a non-white ink can be recorded by a printing method.

(Printed matter)
The printed matter of the present invention has a non-permeable recording medium, and a white printing layer and a non-white printing layer on the non-permeable recording medium, and further includes other layers as necessary.
The white printing layer contains an organic solvent, a coloring material, a styrene acrylic resin, at least one selected from an acrylic urethane resin, a polyester resin, and a polyolefin-modified polyester urethane resin, and further if necessary. And other ingredients.
The non-white printing layer contains an organic solvent and a styrene acrylic resin, preferably contains a coloring material, and further contains other components as necessary.

As the organic solvent and the color material in the white print layer, the same organic solvent and color material of the white ink in the ink set of the present invention can be used.
As the styrene acrylic resin, acrylic urethane resin, polyester resin, and polyolefin-modified polyester urethane resin in the white printed layer, the white ink styrene acrylic resin particles, acrylic urethane resin particles, and polyester resin in the ink set of the present invention Styrene acrylic resin used for the particles and polyolefin-modified polyester urethane resin particles, and the same acryl urethane resin, polyester resin, and polyolefin-modified polyester urethane resin can be used.
As the organic solvent and color material in the non-white ink, the same organic solvent and color material as those of the non-white ink in the ink set of the present invention can be used.
As the styrene acrylic resin particles in the non-white ink, those similar to the urethane resin used for the styrene acrylic resin particles of the non-white ink in the ink set of the present invention can be used.

  Examples of the present invention will be described below, but the present invention is not limited to these examples.

(Preparation Example 1 of Pigment Dispersion)
-Preparation of black pigment dispersion-
After pre-mixing the following prescription mixture, it was circulated and dispersed for 7 hours in a disk-type bead mill (Shinmaru Enterprises Co., Ltd., KDL type, media: zirconia balls with a diameter of 0.3 mm) to obtain a black pigment dispersion (pigment) Solid content concentration: 15% by mass) was obtained.
[Prescription]
Carbon black pigment (trade name: Monarch 800, manufactured by Cabot Corporation): 15 parts by mass Anionic surfactant (trade name: Pionin A-51-B, manufactured by Takemoto Yushi Co., Ltd.): 2 parts by mass 83 parts by mass

(Pigment Dispersion Preparation Example 2)
-Preparation of cyan pigment dispersion-
A cyan pigment dispersion (pigment solid content concentration: 15% by mass) was prepared in the same manner as in Pigment Dispersion Preparation Example 1 except that the carbon black pigment in Pigment Dispersion Preparation Example 1 was changed to Pigment Blue 15: 3. )

(Pigment Dispersion Preparation Example 3)
-Preparation of magenta pigment dispersion-
A magenta pigment dispersion (pigment solid content concentration: 15 mass%) was prepared in the same manner as in Preparation 1 of pigment dispersion except that the carbon black pigment was changed to Pigment Red 122 in Preparation Example 1 of Pigment Dispersion. Obtained.

(Pigment Dispersion Preparation Example 4)
-Preparation of yellow pigment dispersion-
A yellow pigment dispersion (pigment solid content concentration: 15% by mass) was prepared in the same manner as in Pigment Dispersion Preparation Example 1, except that the carbon black pigment in Pigment Dispersion Preparation Example 1 was changed to Pigment Yellow 155. Obtained.

(Pigment Dispersion Preparation Example 5)
-Preparation of white pigment dispersion-
25 parts by mass of titanium oxide (trade name: STR-100W, manufactured by Sakai Chemical Industry Co., Ltd.), 5 parts by mass of a pigment dispersant (trade name: TEGO Dispers 651, manufactured by Evonik), and 70 parts by mass of water are mixed, and a bead mill ( (Trade name: Research Lab, manufactured by Shinmaru Enterprises Co., Ltd.), zirconia beads having a diameter of 0.3 mm were dispersed for 5 minutes at a filling rate of 60% and 8 m / s to obtain a white pigment dispersion.

(Preparation example 1 of polyolefin-modified polyester urethane resin emulsion)
-Preparation of polyolefin-modified polyester urethane resin emulsion 1-
Polyolefin-modified polyester urethane resin emulsion 1 (solid content concentration 30% by mass) was obtained by the same method as that described in Example 9 of JP-A-10-72562.

(Preparation example 2 of polyolefin-modified polyester urethane resin emulsion)
-Preparation of polyolefin-modified polyester urethane resin emulsion 2-
A separable flask equipped with a stirrer, a dropping funnel with two pressure equalizing tubes, a thermometer, and a water-cooled condenser has an ethylene component content of 48 mol%, a number average molecular weight (Mn) of 3,600 g / mol, Mw 166.91 g of an ethylene / propylene copolymer having a / Mn of 1.65 was charged and nitrogen substitution was performed.
Then, after raising the temperature to 160 ° C., 490.60 g of light acrylate HOB-A (manufactured by Kyoeisha Chemical Co., Ltd., 2-hydroxybutyl acrylate) weighed in the dropping funnel at the same temperature, and 10.71 g of excess Di (tert-butyl oxide) (manufactured by Katayama Chemical Co., Ltd.) was added dropwise over 2 hours.
After dropping, the reaction was carried out at 160 ° C. for 2 hours, then the temperature was raised to 170 ° C., and a reduced pressure treatment was carried out for 3 hours under the conditions of 170 ° C. and 1.33 kPa or less to obtain a polyolefin-modified polyol.
Next, in a reaction vessel into which a stirrer, a reflux condenser, and a thermometer were inserted, 1,500 g of Polylite OD-X-2420 (manufactured by DIC Corporation, polyester polyol), 200 g of the polyolefin-modified polyol, 2,2-dimethylol. Propionic acid (DMPA) 220 g and N-methylpyrrolidone (NMP) 1,347 g were charged under a nitrogen stream 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) are added and heated to 90 ° C., and a urethanization reaction is performed over 5 hours. Obtained. The reaction mixture was cooled to 80 ° C., 149 g of triethylamine was added thereto, 4,340 g was extracted from the mixture, and added to a mixed solution of 5,400 g of water and 15 g of triethylamine with vigorous stirring. .
Next, 1,500 g of ice was added, and 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 became 30% by mass. As a result, a polyolefin-modified polyester urethane resin emulsion 2 was obtained.

(Example 1-1)
<Preparation of ink set A-1>
-Preparation of black ink-
Black pigment dispersion 20% by mass produced by the method shown in Preparation Example 1 for pigment dispersion, styrene acrylic resin emulsion (J-450, manufactured by Johnson Polymer Co., Ltd., solid content concentration 42% by mass) 16.7% %, 1,2-propanediol 12% by mass, 1,3-propanediol 10% by mass, 1,2-butanediol 3% by mass, 2,3-butanediol 3% by mass, 2-methyl-2,4- Pentanediol 3% by weight, dipropylene glycol monomethyl ether 4% by weight, trade name “FS-300” (manufactured by DuPont, fluorine-based surfactant, nonvolatile content 40% by weight) 1% by weight, preservative Product name: Proxel LV (manufactured by Avicia) 0.1% by mass and high-purity water were added so that the remaining amount was 100% by mass. This was mixed and stirred, and filtered with a polypropylene filter having an average pore size of 0.2 μm (trade name: Betafine polypropylene pleated filter PPG series, manufactured by 3M Corporation) to prepare a black ink. This ink was used as the black ink of ink set A-1.

-Preparation of cyan ink-
A cyan ink was obtained in the same manner as in the preparation of the black ink except that the pigment dispersion to be added was changed to a cyan pigment dispersion prepared by the method shown in Preparation Example 2 for pigment dispersion. This ink was used as the cyan ink of ink set A-1.

-Preparation of magenta ink-
A magenta ink was obtained in the same manner as the black ink except that the pigment dispersion to be added was changed to the magenta pigment dispersion prepared by the method shown in Preparation Example 3 for pigment dispersion. This ink was used as magenta ink of ink set A-1.

-Preparation of yellow ink-
A yellow ink was obtained in the same manner as in the preparation of the black ink except that the pigment dispersion to be added was changed to the yellow pigment dispersion prepared by the method shown in Preparation Example 4 for pigment dispersion. This ink was used as the yellow ink of ink set A-1.

-Preparation of white ink-
The pigment dispersion to be added is changed to the white pigment dispersion prepared by the method shown in Preparation Example 5 for pigment dispersion, and the amount of styrene acrylic resin emulsion (J-450, manufactured by Johnson Polymer Co., Ltd.) added is 8 3% by mass, acrylic urethane resin emulsion (manufactured by Taisei Fine Chemical Co., Ltd., WEM-3000, acrylic-urethane / hybrid microemulsion, solid content 33% by mass, mass ratio (urethane / acrylic) = 8/2, A white ink was obtained in the same manner as in the preparation of the black ink except that 10.7% by mass of pH = 7.6) was added. This ink was used as the white ink of ink set A-1.

(Example 1-2)
-Preparation of ink set B-1-
Ink set B of white ink and non-white ink was carried out in the same manner as in Example 1-1 except that 6% by mass of 3-methoxy-3-methyl-1-butanol was added as an organic solvent in Example 1-1. -1 was obtained.

(Example 1-3)
-Preparation of ink set C-1-
Ink set C of white ink and non-white ink was carried out in the same manner as in Example 1-1 except that 5% by mass of 3-methoxy-3-methyl-1-butanol was added as an organic solvent in Example 1-1. -1 was obtained.

(Example 1-4)
-Preparation of ink set D-1-
In Example 1-1, an acrylic urethane resin emulsion of white ink (manufactured by Taisei Fine Chemical Co., Ltd., WEM-3000, acrylic-urethane / hybrid type microemulsion, solid content 33 mass%, mass ratio (urethane / acrylic) = 8 / 2, pH = 7.6) 10.7% by mass of acrylic urethane resin emulsion (manufactured by Taisei Fine Chemical Co., Ltd., WEM-200U, acrylic-urethane hybrid type microemulsion, mass ratio (urethane / acrylic ratio)) = 5 / 5, solid content 38% by mass, pH = 7) Ink set D-1 of white ink and non-white ink was obtained in the same manner as Example 1-1 except that the content was changed to 9.3% by mass.

(Example 1-5)
-Preparation of ink set E-1-
In Example 1-1, white ink and non-white ink were used in the same manner as in Example 1-1 except that 5% by mass of 3-methoxy-3-methyl-1-butanol was added to only the white ink. Set E-1 was obtained.

(Comparative Example 1-1)
-Preparation of ink set F-1-
In Example 1-1, an ink set F-1 of white ink and non-white ink was obtained in the same manner as in Example 1-1, except that the acrylic urethane resin emulsion of white ink was not added.

(Comparative Example 1-2)
-Preparation of ink set G-1-
In Example 1-1, an ink set G-1 of white ink and non-white ink was obtained in the same manner as in Example 1-1 except that the styrene acrylic resin emulsion of white ink was not added.

(Comparative Example 1-3)
-Preparation of ink set H-1-
In Example 1-1, white ink and non-white ink were prepared in the same manner as in Example 1-1 except that the styrene acrylic resin emulsion of non-white ink (black ink, magenta ink, cyan ink, yellow ink) was not added. Ink set H-1 of white ink was obtained.

Next, an ink jet printer (device name: IPSiO GXe5500 remodeling machine, manufactured by Ricoh Co., Ltd.) is filled using the ink sets of Examples 1-1 to 1-5 and Comparative Examples 1-1 to 1-3. Then, printing was performed on the recording medium.
As the recording medium, an impermeable recording medium (acrylic resin film, trade name: transparent acrylic film SPC-0640, manufactured by Mimaki Engineering Co., Ltd.) was used.

-White bottom image formation-
First, white ink was printed on a recording medium, and a solid image with an ink adhesion amount of 0.6 g / cm ² was printed. After printing, the solid image was dried for 3 minutes on a hot plate (NINOS ND-1, manufactured by ASONE CORPORATION) set at 80 ° C.

-Formation of color solid images-
A solid image of a single color of each color ink was formed on the solid image of white ink provided on the recording medium, and similarly, a hot plate set at 80 ° C. (NINOS ND-1, manufactured by ASONE CORPORATION) An image obtained by drying for 3 minutes and printing a solid image of a single color ink on a solid image of white ink was created for each color and printed on a solid white image. An image, a magenta single-color solid image, a yellow single-color solid image, and a black single-color solid image were obtained. Note that the IPSiO GXe5500 modified machine is equivalent to a recording speed of 30 m ² / hr with a printing width of 150 cm. Was modified so that it could be reproduced in A4 size, and the pot plate was installed, and the heating conditions (heating temperature, heating time) after recording were changed. It was modified so as to be able to obtain.

<Glossiness>
About the monochromatic solid image of the black ink formed on the acrylic resin film by the said method, five places were measured using the gloss meter (the BYK Gardner company make, micro trigloss), and the average value was made into glossiness. Each of 20 ° gloss and 60 ° gloss was measured. The results are shown in Table 9.

<Adhesion>
About each solid image formed on the recording medium of the acrylic resin film, the number of remaining cells of 100 test cells is counted by a cross-cut peel test using a cloth adhesive tape (manufactured by Nichiban Co., Ltd., 123LW-50), Based on the following evaluation criteria, “adhesion” to the recording medium was evaluated. The results are shown in Table 9. In addition, it is a level which can endure actual use that the said evaluation is B or more.
[Evaluation criteria]
AA: The number of remaining cells is 98 or more A: The number of remaining cells is 90 or more and less than 98 B: The number of remaining cells is 70 or more and less than 90 C: The number of remaining cells is less than 70

<Abrasion resistance>
After drying each solid image formed on the recording medium of the acrylic resin film, a load of 400 g was applied with a cotton cloth (Kanakin No. 3), and the image area was rubbed 100 times, and the image peeling of the image area was observed visually, The rubbing property was evaluated from the following three viewpoints.
(1) Change in color of the rubbed portion and the unrubbed portion (2) Exposure of the white ink layer in the rubbed portion (3) Exposure of the recording medium in the rubbed portion It was evaluated according to the evaluation criteria. A to C are levels that can withstand actual use, and D is a level that is incompatible with actual use. In the single-color solid image of each color of magenta, cyan, black, and yellow, the result of the color with the worst result was described as the evaluation result. The results are shown in Table 9.
[(1) Evaluation criteria for color change]
A: I do not know the rubbed part and the part that is not rubbed. B: If I observe it closely, the color changes slightly between the rubbed part and the non-rubbed part. D: The color change is noticeable between the rubbed part and the non-rubbed part [(2) Evaluation criteria for white ink layer exposure]
A: The white ink layer is not exposed at all. B: When observed closely, there are a few portions where the white ink layer is exposed. C: There is a portion where the white ink layer is exposed although it is not conspicuous. D: The exposure of the white ink layer is conspicuous [(3) Evaluation criteria for recording medium exposure]
A: The recording medium is not exposed at all. B: When observed closely, there are a few portions where the recording medium is exposed. C: There is a portion where the recording medium is exposed although it is not noticeable. D: White ink layer The exposure of

(Example 2-1)
-Preparation of ink set A-2-
In Example 1-1, an acrylic urethane resin emulsion of white ink (manufactured by Taisei Fine Chemical Co., Ltd., WEM-3000, acrylic-urethane / hybrid type microemulsion, solid content 33 mass%, mass ratio (urethane / acrylic) = 8 / 2, pH = 7.6) Example 1-1 except that 10.7% by mass was changed to 8.8% by mass of a polyester resin emulsion (Toyobo Co., Ltd., MD-2000, solid content: 40% by mass). In the same manner, an ink set A-2 of white ink and non-white ink was obtained.

(Example 2-2)
-Preparation of ink set B-2-
Ink set B of white ink and non-white ink was performed in the same manner as in Example 2-1, except that 6% by mass of 3-methoxy-3-methyl-1-butanol was added as an organic solvent in Example 2-1. -2 was obtained.

(Example 2-3)
-Preparation of ink set C-2-
Ink set C of white ink and non-white ink was carried out in the same manner as in Example 2-1, except that 5% by mass of 3-methoxy-3-methyl-1-butanol was added as an organic solvent in Example 2-1. -2 was obtained.

(Example 2-4)
-Preparation of ink set D-2-
In Example 2-1, 8.8% by mass of a white ink polyester resin emulsion (Toyobo Co., Ltd., MD-2000, solid content 40% by mass) was added to a polyester resin emulsion (Keiro Chemical Industry Co., Ltd., plus coat). Z-221, solid content 20 mass%) Except for changing to 17.6 mass%, an ink set D-2 of white ink and non-white ink was obtained in the same manner as in Example 2-1.

(Example 2-5)
-Preparation of ink set E-2-
Ink set of white ink and non-white ink in the same manner as in Example 2-1, except that 5% by mass of 3-methoxy-3-methyl-1-butanol was added to only the white ink in Example 2-1. E-2 was obtained.

(Comparative Example 2-1)
-Preparation of ink set F-2-
In Example 2-1, an ink set F-2 of white ink and non-white ink was obtained in the same manner as in Example 2-1, except that the polyester resin emulsion of white ink was not added.

(Comparative Example 2-2)
-Preparation of ink set G-2-
In Example 2-1, an ink set G-2 of white ink and non-white ink was obtained in the same manner as in Example 2-1, except that the styrene acrylic resin emulsion of white ink was not added.

(Comparative Example 2-3)
-Preparation of ink set H-2-
In Example 2-1, white ink and non-white ink were non-added in the same manner as in Example 2-1, except that the styrene acrylic resin emulsion of non-white ink (black ink, magenta ink, cyan ink, yellow ink) was not added. Ink set H-2 of white ink was obtained.

  Next, the contents of Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-3 are summarized in Tables 10 to 17.

Next, various characteristics were evaluated in the same manner as in Example 1-1 using the ink sets of Examples 2-1 to 2-5 and Comparative Examples 2-1 to 2-3. The results are shown in Table 18.
As the recording medium, an impermeable recording medium (polyester resin film, manufactured by Toray Industries, Inc., Lumirror type S10) was used.

(Example 3-1)
-Preparation of ink set A-3-
In Example 1-1, an acrylic urethane resin emulsion of white ink (manufactured by Taisei Fine Chemical Co., Ltd., WEM-3000, acrylic-urethane / hybrid type microemulsion, solid content 33 mass%, mass ratio (urethane / acrylic) = 8 / 2, pH = 7.6) Ink set of white ink and non-white ink in the same manner as in Example 1-1 except that the polyolefin-modified polyester urethane resin emulsion 1 (solid content concentration 30% by mass) was replaced. A-3 was obtained.

(Example 3-2)
-Preparation of ink set B-3-
Ink set B of white ink and non-white ink was performed in the same manner as in Example 3-1, except that 6% by mass of 3-methoxy-3-methyl-1-butanol was added as an organic solvent in Example 3-1. -3 was obtained.

(Example 3-3)
-Preparation of ink set C-3-
Ink set C of white ink and non-white ink was performed in the same manner as in Example 3-1, except that 5% by mass of 3-methoxy-3-methyl-1-butanol was added as an organic solvent in Example 3-1. -3 was obtained.

(Example 3-4)
-Preparation of ink set D-3-
In Example 3-1, the polyolefin-modified polyester urethane resin emulsion 1 (solid content concentration 30% by mass 10.7% by mass) of the white ink, the polyolefin-modified polyester urethane resin emulsion 2 (solid content concentration 30% by mass) 9.3% by mass. % Ink set D-3 of white ink and non-white ink was obtained in the same manner as in Example 3-1, except for changing to%.

(Example 3-5)
-Preparation of ink set E-3-
Ink set of white ink and non-white ink was obtained in the same manner as in Example 3-1, except that 5% by mass of 3-methoxy-3-methyl-1-butanol was added to only the white ink in Example 3-1. E-3 was obtained.

(Comparative Example 3-1)
-Preparation of ink set F-3-
In Example 3-1, white ink and non-white ink set F-3 were obtained in the same manner as Example 3-1, except that the polyolefin-modified polyester urethane resin emulsion 1 of white ink was not added. .

(Comparative Example 3-2)
-Preparation of ink set G-3-
In Example 3-1, an ink set G-3 of white ink and non-white ink was obtained in the same manner as Example 3-1, except that the styrene acrylic resin emulsion of white ink was not added.

(Comparative Example 3-3)
-Preparation of ink set H-3-
In Example 3-1, a white ink and a non-white ink were prepared in the same manner as in Example 3-1, except that a styrene acrylic resin emulsion of a non-white ink (black ink, magenta ink, cyan ink, yellow ink) was not added. Ink set H-3 of white ink was obtained.

  Next, Tables 19 to 26 show the contents of Examples 3-1 to 3-5 and Comparative Examples 3-1 to 3-3.

Next, various characteristics were evaluated in the same manner as in Example 1-1 using the ink sets of Examples 3-1 to 3-5 and Comparative Examples 3-1 to 3-3. The results are shown in Table 27.
As the recording medium, an impermeable recording medium (polypropylene resin film, manufactured by Toyobo Co., Ltd., Pyrene P2102) was used.

Aspects of the present invention are as follows, for example.
<1> An ink set having non-white ink and white ink,
The white ink contains water, an organic solvent, a coloring material, styrene acrylic resin particles, at least one selected from acrylic urethane resin particles, polyester resin particles, and polyolefin-modified polyester urethane resin particles,
In the ink set, the non-white ink contains water, an organic solvent, and styrene acrylic resin particles.
<2> The ink set according to <1>, wherein the styrene acrylic resin particles contained in the white ink and the styrene acrylic resin particles contained in the non-white ink are the same.
<3> The ink set according to any one of <1> to <2>, wherein the organic solvent contained in the non-white ink and the organic solvent contained in the white ink are the same.
<4> The ink set according to any one of <1> to <3>, wherein the organic solvent in the non-white ink and the white ink includes 3-methoxy-3-methyl-1-butanol.
<5> The ink set according to <4>, wherein the content of 3-methoxy-3-methyl-1-butanol is 5% by mass or less.
<6> The ink set according to any one of <1> to <5>, wherein the color material in the white ink is a metal oxide.
<7> The ink set according to <6>, wherein the metal oxide is titanium oxide.
<8> The ink set according to any one of <1> to <7>, wherein the content of the color material in the white ink is 1% by mass to 10% by mass with respect to the total amount of the white ink. .
<9> The ink set according to any one of <1> to <8>, wherein the white ink and the non-white ink have a viscosity at 25 ° C. of 5 mPa · s to 30 mPa · s.
<10> The ink set according to any one of <1> to <9>, wherein the non-white ink is at least one selected from black ink, cyan ink, magenta ink, and yellow ink. .
<11> The ink set according to any one of <1> to <10>, wherein the white ink and the non-white ink further include a surfactant.
<12> The ink set according to <11>, wherein the surfactant is a fluorine surfactant.
<13> The ink according to any one of <11> to <12>, wherein the content of the surfactant is 0.001% by mass or more and 5% by mass or less with respect to the total amount of the white ink or the non-white ink. Is a set.
<14> A printed matter having a white print layer and a non-white print layer on a non-permeable recording medium,
The white printed layer contains an organic solvent, a color material, a styrene acrylic resin, an acrylic urethane resin, a polyester resin, and at least one selected from a polyolefin-modified polyester urethane resin,
The non-white print layer contains an organic solvent and a styrene acrylic resin.
<15> The printed matter according to <14>, wherein the impermeable recording medium is at least one selected from an acrylic resin film, a polyester resin film, and a polypropylene resin film.
<16> A white ink application step of applying a white ink in the ink set according to any one of <1> to <13> on a non-permeable recording medium;
An image forming step of forming an image by applying the non-white ink in the ink set according to any one of <1> to <13> on the surface to which the white ink has been applied, Is a printing method.
<17> The printing method according to <16>, wherein the impermeable recording medium is at least one selected from an acrylic resin film, a polyester resin film, and a polypropylene resin film.
<18> An ink storage unit that stores each ink included in the ink set according to any one of <1> to <13>,
An ink discharge head for dropping the ink by energy to discharge the ink.
<19> The printing apparatus according to <18>, wherein the impermeable recording medium is at least one selected from an acrylic resin film, a polyester resin film, and a polypropylene resin film.

  The ink set according to any one of <1> to <13>, the printed material according to any one of <14> to <15>, the printing method according to any one of <16> to <17>, The printing apparatus according to any one of <18> to <19> can solve the conventional problems and achieve the object of the present invention.

JP 2011-252169 A Japanese Patent No. 5770209

400 Image forming apparatus 411 Ink container 434 Ink ejection head (inkjet recording head)

Claims (8)

An ink set having non-white ink and white ink,
The white ink contains water, an organic solvent, a coloring material, styrene acrylic resin particles, at least one selected from acrylic urethane resin particles, polyester resin particles, and polyolefin-modified polyester urethane resin particles,
The ink set, wherein the non-white ink contains water, an organic solvent, and styrene acrylic resin particles.   The ink set according to claim 1, wherein the styrene acrylic resin particles contained in the white ink and the styrene acrylic resin particles contained in the non-white ink are the same.   The ink set according to claim 1, wherein the organic solvent contained in the non-white ink and the organic solvent contained in the white ink are the same.   The ink set according to any one of claims 1 to 3, wherein the organic solvent in the non-white ink and the white ink contains 3-methoxy-3-methyl-1-butanol.   The ink set according to claim 4, wherein a content of the 3-methoxy-3-methyl-1-butanol is 5% by mass or less. A printed matter having a white print layer and a non-white print layer on a non-permeable recording medium,
The white printed layer contains an organic solvent, a color material, a styrene acrylic resin, an acrylic urethane resin, a polyester resin, and at least one selected from a polyolefin-modified polyester urethane resin,
The printed matter, wherein the non-white print layer contains an organic solvent and a styrene acrylic resin. A white ink applying step for applying a white ink in the ink set according to any one of claims 1 to 5 on a non-permeable recording medium;
An image forming step of forming an image by applying the non-white ink in the ink set according to any one of claims 1 to 5 on the surface to which the white ink is applied. . An ink containing portion containing each ink contained in the ink set according to any one of claims 1 to 5;
A printing apparatus comprising: an ink discharge head configured to drop and discharge the ink by energy.