JP6745652B2 - Ink set and printing method - Google Patents

Description

The present invention relates to an ink set and a printing method using the ink set, and particularly to a print layer having good fixability without suppressing gloss of a print layer and corrosion of a printing device and reducing gloss. The present invention relates to an ink set capable of forming ink.

Although various inks have been developed as inks used for printing by an inkjet printer, water-based inks are widely used from the viewpoint of reducing environmental load. However, since the water-based ink contains water as a solvent, it tends to cause bleeding during printing. As a method for improving the bleeding of the printed layer formed by printing, for example, a treatment liquid having an action of aggregating the pigment in the colored ink is used in combination to suppress the bleeding of the printed layer and to improve the fixing property to the substrate. Techniques for forming a good print layer are known. A water-based ink set in which such a treatment liquid and a colored ink are combined is referred to as a two-liquid reactive water-based ink set.

Japanese Patent Application Laid-Open No. 6-57192 (Patent Document 1) describes an ink set including a plurality of colored inks, which includes a black ink containing an anionic dye and a yellow ink containing a cationic dye. , It is described that the use of these dyes reduces the bleeding between the color and the black, and further describes that the bleeding can be reduced by blending a polyvalent precipitant in the yellow ink. .. In Patent Document 1, it is recognized that this yellow ink also acts as a treatment liquid.

Japanese Patent Application Laid-Open No. 2009-190379 (Patent Document 2) discloses a color ink containing a pigment (water-dispersible pigment) coated with a cross-linked water-soluble polymer, and a colorless ink containing an aggregation accelerator that promotes aggregation of the pigment. It describes that an ink set containing and is provided, whereby the liquid stability and dischargeability are improved, and curling and image deformation of the recording medium after application of the ink can be suppressed.

JP-A-6-57192 JP, 2009-190379, A

However, when the inkjet ink set described in Patent Document 1 is used, the presence of the polyvalent precipitating agent in the ink may corrode the metal part (especially the print head) of the printing device such as a printer. Further, even when the aggregation accelerator as described in Patent Document 2 is used, there is a possibility that corrosion will occur similarly.

Further, from the viewpoint of ensuring coating film performance such as water resistance, a resin is widely used as a binder for an aqueous ink, and is usually dispersed in the ink in the form of an emulsion. However, if the dispersed resin particles are contained in both the colored ink and the treatment liquid that form the two-component reactive water-based ink set, there is a problem that the fixability of the printing layer to the substrate cannot be sufficiently obtained. is there. In order to solve this problem, a method of adding a water-soluble polymer to the treatment liquid has been proposed, but since the treatment liquid containing the water-soluble polymer is generally acidic, it may cause corrosion. Further, it is possible to make the treatment liquid neutral or basic by adding a corrosion inhibitor or other neutralizing agent, but in this case, the coagulation effect expected of the treatment liquid is not sufficiently exerted and bleeding is prevented. Will be generated.

Incidentally, in the two-liquid reaction type water-based ink set, it is also important to control the timing of aggregation. For example, if the treatment liquid has a strong aggregating action and the agglomeration occurs too early, irregularities are formed on the surface of the printing layer, which causes a decrease in the gloss of the printing layer.

Therefore, an object of the present invention is to solve the above-mentioned problems of the prior art, suppress the occurrence of bleeding of the printing layer and the occurrence of corrosion of the printing device, and form a printing layer having good fixability without lowering gloss. It is to provide an ink set capable of performing the above. Another object of the present invention is to provide a printing method using such an ink set.

The present inventor, as a result of extensive studies to achieve the above object, uses a self-dispersing pigment as a pigment of an aqueous coloring ink, and uses a water-soluble polymer having a quaternary ammonium cation as a resin of an aqueous coating liquid. As a result, they have found that the desired aggregating effect can be exhibited even when the pH of the aqueous coating liquid is in the basic region, and have completed the present invention.

That is, the ink set of the present invention is an ink set containing a water-based coloring ink and a water-based coating liquid,
The water-based colored ink contains water, a self-dispersible pigment, a water-soluble solvent and a resin, the water-based coating liquid contains water, a water-soluble solvent and a resin, the resin contained in the water-based coating liquid is quaternary A water-soluble polymer having an ammonium cation is contained, and the pH of the aqueous coating solution is in the range of 7.1 to 10.0.

In a preferred example of the ink set of the present invention, the ratio of the water-soluble polymer having a quaternary ammonium cation in the resin in the aqueous coating liquid is 50% by mass or more.

In another preferred embodiment of the ink set of the present invention, the water-soluble solvent contained in the water-based colored ink and the coating liquid is selected from the group consisting of glycol ether, a 3- to 5-membered lactone compound, an amide compound and an alkanediol. At least one selected type is included.

Further, the printing method of the present invention is a printing method of forming a printing layer including a coating layer and a colored ink layer on a substrate by an inkjet printer using the above ink set, wherein the aqueous coating liquid is used as a print head. A step of forming a coating layer by ejecting the coating liquid droplets onto the substrate by ejecting from the print head, and ejecting the water-based colored ink from the print head to deposit the ink droplets onto the coating layer. And a step of forming a colored ink layer.

According to the ink set of the present invention, it is possible to provide an ink set capable of suppressing the occurrence of bleeding of a printing layer and the occurrence of corrosion of a printing device and forming a printing layer having good fixability without lowering gloss. can do. Further, according to the printing method of the present invention, it is possible to provide a printing method using such an ink set.

The ink set of the present invention will be described in detail below. The ink set of the present invention is an ink set containing a water-based coloring ink and a water-based coating liquid, wherein the water-based coloring ink contains water, a self-dispersible pigment, a water-soluble solvent and a resin, and the water-based coating liquid is Water, a water-soluble solvent and a resin, the resin contained in the water-based coating liquid contains a water-soluble polymer having a quaternary ammonium cation, and the pH of the water-based coating liquid is in the range of 7.1 to 10.0. It is characterized by being in.

The ink set of the present invention is an ink set containing a water-based coloring ink and a water-based coating liquid. The water-based coloring ink may be used alone, or two or more colors of water-based coloring ink may be combined. Here, "two or more colors of water-based colored ink" means two or more kinds of water-based colored inks that emit different colors.

In the ink set of the present invention, the water-based colored ink is an ink containing water, a self-dispersible pigment, a water-soluble solvent and a resin, and is preferably an inkjet ink. The inkjet ink is an ink composition for inkjet printers. In the ink set of the present invention, the water-based coating liquid is a liquid for coating the base material and aggregating the colored ink, and contains water, a water-soluble solvent and a resin, and can be used in an inkjet printer. It is preferably a coating liquid. In the present invention, a composition containing a colorant in an amount of more than 0.1% by mass is referred to as an “ink”, and a composition containing no colorant or containing 0.1% by mass or less of the colorant is simply referred to as “liquid”. ".

In the ink set of the present invention, the aqueous coating liquid has a pH in the range of 7.1 to 10.0. By setting the pH of the aqueous coating liquid in such a basic region, it is possible to suppress the occurrence of corrosion in the metal part (especially the print head) of the printing device such as a printer. On the other hand, although the pH of the water-based coloring ink changes depending on the type of the selected pigment, it is preferably basic for the same reason, and the pH is in the range of 7.1 to 10.0. Is preferred. A pH adjuster can be used to adjust the pH, but the use of an amine compound is preferable, and the use of an amine compound having a boiling point of 70 to 270°C is more preferable. The amine compound has an effect of appropriately adjusting the pH in the water-based coating liquid or the water-based colored ink, and also having an effect of preventing the aggregation of the resin. Further, by adding the amine compound to the ink or the coating liquid, it is possible to make corrosion less likely to occur. Furthermore, when the boiling point of the amine compound is in the range of 70 to 270° C., it is difficult to evaporate, and the amine compound remains in the water-based coloring ink or the water-based coating liquid for a long period of time, and the discharge stability of the water-based coloring ink or the water-based coating liquid is stable. The properties are excellent over a long period of time, and the gloss of the printed layer tends to be high. Specific examples of the amine compound having a boiling point of 70 to 270° C. include N-methyldiethanolamine, N-ethyldiethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine and the like. These amine compounds may be used alone or in combination of two or more. In the water-based colored ink and the water-based coating liquid, the content of the amine compound is preferably 0.1 to 2.0 mass% independently.

The resin used in the aqueous coating liquid contains a water-soluble polymer having a quaternary ammonium cation. Since the above water-soluble polymer has a quaternary ammonium cation (cationized nitrogen atom), it exhibits the ability to aggregate the pigment even when it is present in the aqueous coating liquid having a pH in the basic region. You can However, since the above water-soluble polymer has a high ability to aggregate the pigment, aggregation of the pigment occurs remarkably quickly, and there is a problem that the gloss of the printing layer decreases, so it is important to combine it with the self-dispersing pigment described below. become. As a result, it is possible to suppress the occurrence of corrosion of the printing device and the occurrence of bleeding of the printing layer, to form a printing layer with good fixability to the substrate, and to prevent the gloss of the printing layer from decreasing. it can.
In the present invention, the water-soluble polymer means a polymer which is soluble in water or an aqueous solution containing a water-soluble organic solvent in an amount of less than 50% by mass.

The proportion of the water-soluble polymer having a quaternary ammonium cation in the resin contained in the aqueous coating liquid is preferably 50% by mass or more from the viewpoint of appropriately controlling the aggregation action.

As the other resin that can be used in the water-based coating liquid, a water-soluble resin other than the water-soluble polymer having a quaternary ammonium cation that is commonly used in the ink industry can be used. For example, acrylic resin, silicone resin, acrylic silicone resin, styrene acrylic copolymer resin, polyester resin, rosin resin, phenol resin, urethane resin, melamine resin, urea resin, epoxy resin, cellulose resin, butyral resin, maleic acid resin, fumar Examples thereof include acid resins and vinyl resins. These resins may be used alone or in combination of two or more.

As the water-soluble polymer having a quaternary ammonium cation, a commercially available product can be used, and from the viewpoint that it can stably exist even in a basic state, for example, Catiomaster PD-7, PD-30 (manufactured by Yokkaichi Gosei Co., Ltd.), Examples include the reaction products of epichlorohydrin and alkylamine, which are commercially available under the names of CP-230, CP-910 (all manufactured by Harima Kasei), DK6810, DK6851, and DK6853 (all manufactured by Hoshiko PMC).

The resin used for the water-based colored ink is not particularly limited, and a resin usually used in the ink industry can be used. For example, acrylic resin, silicone resin, acrylic silicone resin, styrene-acrylic copolymer resin, Polyester resin, rosin resin, petroleum resin, coumarone resin, phenol resin, urethane resin, melamine resin, urea resin, epoxy resin, cellulose resin, xylene resin, alkyd resin, aliphatic hydrocarbon resin, butyral resin, maleic acid resin, fumar Examples thereof include acid resins and vinyl resins. These resins may be used alone or in combination of two or more.

The content of the resin in the water-based colored ink is preferably 1 to 10% by mass. In addition, the content of the resin in the aqueous coating liquid is preferably 0.5 to 15% by mass.

The water-based coloring ink contains a self-dispersing pigment. The self-dispersing pigment is a pigment that can maintain a dispersed state in the ink without using a pigment dispersant, and is usually obtained by providing a surface with a functional group having excellent hydrophilicity. The present inventor, in the case of the combination of the water-soluble polymer having a quaternary ammonium cation described above and the self-dispersing pigment, prevents the formation of irregularities on the surface of the printing layer due to the occurrence of aggregation too early. It was found that it is possible to prevent the deterioration of the gloss of the printed layer.

In the present invention, the self-dispersible pigment is preferably a pigment having an anion such as a carboxyl ion, a sulfate ion, a nitrate ion, a phosphate ion or a hydroxide ion directly bonded to the surface. By using such an anion type self-dispersible pigment, the pigment can be stably dispersed in the ink without adding a dispersant, and a clearer image can be printed. Commercially available products can be preferably used as these anionic self-dispersing pigments.

The pigment that can be used as the self-dispersing pigment is not particularly limited, and pigments such as organic pigments and inorganic pigments that are commonly used as colorants in the ink industry can be used. Examples of the pigment include Pigment Yellow 12, 13, 14, 17, 20, 24, 31, 42, 53, 55, 74, 83, 86, 93, 109, 110, 117, 120, 122, 125, 128, 129, 137, 138, 139, 147, 148, 150, 151, 152, 153, 154, 155, 166, 168, 180, 181, 184, 185, 213; Pigment Orange 16, 36, 38, 43, 51, 55, 59, 61, 64, 65, 71; Pigment Red 9, 48, 49, 52, 53, 57, 97, 101, 122, 123, 149, 168, 177, 180, 192, 202, 206, 215, 216, 217, 220, 223, 224, 226, 227, 228, 238, 240, 244, 254; Pigment Violet 19, 23, 29, 30, 32, 37, 40, 50; Pigment Blue 15, 15:1, 15:3, 15:4, 15:6, 22, 27, 28, 29, 30, 60, 64, 80; Pigment Green 7, 36; Pigment Brown 23, 25, 26; and Pigment Black 1, 7, 26. , 27, 28, Pigment White 6 and the like. These pigments may be used alone or in combination of two or more.

The content of the self-dispersing pigment in the water-based coloring ink can be arbitrarily determined depending on the type of pigment used and the like, but it is preferably 0.5 to 10% by mass in the water-based coloring ink.

The water-soluble solvent used in the water-based colored ink and the water-based coating liquid is not particularly limited, and a water-soluble solvent usually used in the ink industry can be used. In the water-based coloring ink and the water-based coating liquid, the content of the water-soluble solvent is preferably 60% by mass or less, independently of each other. Although the lower limit of the content of the water-soluble solvent is not particularly limited, it is usually preferably 5% by mass or more.

The water-soluble solvent is selected from the group consisting of glycol ethers, 3- to 5-membered ring lactone compounds, amide compounds, and alkanediols from the viewpoint of improving ejection stability, wettability, and storage stability of inks and coating liquids. It is preferable to include at least one selected.

Specific examples of glycol ethers include ethylene glycol methyl ether, ethylene glycol ethyl ether, ethylene glycol propyl ether, ethylene glycol butyl ether, ethylene glycol pentyl ether, ethylene glycol hexyl ether, ethylene glycol cyclohexyl ether, ethylene glycol phenyl ether, ethylene glycol benzyl. Ether, ethylene glycol isobutyl ether, ethylene glycol tertiary butyl ether, diethylene glycol methyl ether, diethylene glycol ethyl ether, diethylene glycol propyl ether, diethylene glycol butyl ether, diethylene glycol pentyl ether, diethylene glycol hexyl ether, diethylene glycol cyclohexyl ether, diethylene glycol phenyl ether, diethylene glycol benzyl ether, diethylene glycol mono ether Butyl ether, diethylene glycol isobutyl ether, triethylene glycol methyl ether, triethylene glycol ethyl ether, triethylene glycol propyl ether, triethylene glycol butyl ether, triethylene glycol pentyl ether, triethylene glycol hexyl ether, triethylene glycol cyclohexyl ether, triethylene glycol Ethylene glycol ethers such as phenyl ether, triethylene glycol benzyl ether and triethylene glycol monobutyl ether, and propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol propyl ether, propylene glycol butyl ether, propylene glycol pentyl ether, propylene glycol hexyl ether , Propylene glycol cyclohexyl ether, dipropylene glycol methyl ether, dipropylene glycol ethyl ether, dipropylene glycol propyl ether, dipropylene glycol butyl ether, dipropylene glycol pentyl ether, dipropylene glycol hexyl ether, dipropylene glycol cyclohexyl ether, tripropylene glycol Methyl ether, tripropylene glycol ethyl ether, tripropylene glycol propyl ether, tripropylene glycol Examples thereof include propylene glycol ethers such as chill ether, tripropylene glycol pentyl ether, tripropylene glycol hexyl ether, and tripropylene glycol cyclohexyl ether. Among these, ethylene glycol monobutyl ether, ethylene glycol isobutyl ether, ethylene glycol tertiary butyl ether, diethylene glycol monobutyl ether, diethylene glycol isobutyl ether and triethylene glycol monobutyl ether are preferable.

The 3- to 5-membered lactone compound is a compound having a lactone ring partially containing -C(=O)-O-, which is a three-membered ring having 3 atoms constituting the ring and 4 atoms. Which is a 4-membered ring or a 5-membered ring having 5 atoms. Specific examples include α-acetolactone, β-propionlactone, γ-butyrolactone, δ-valerolactone and the like. Of these, γ-butyrolactone is preferable.

The amide compound is preferably an acyclic amide compound, for example, dimethylacetamide, dimethylformamide, sulfanilamide, toluenesulfonamide, benzenesulfonamide, N-dimethyl-β-methoxypropionamide, N,N-dimethyl-β-butoxy. Propionamide, N,N-dimethyl-β-pentoxypropionamide, N,N-dimethyl-β-hexoxypropionamide, N,N-dimethyl-β-heptoxypropionamide, N,N-dimethyl-β- 2-ethylhexoxypropionamide, N,N-dimethyl-β-octoxypropionamide, N,N-diethyl-β-methoxypropionamide, N,N-diethyl-β-butoxypropionamide, N,N-diethyl -Β-pentoxypropionamide, N,N-diethyl-β-hexoxypropionamide, N,N-diethyl-β-heptoxypropionamide, N,N-diethyl-β-octoxypropionamide and the like can be mentioned. .. Among these, dimethylacetamide, dimethylformamide, N,N-dimethyl-β-methoxypropionamide, N,N-dimethyl-β-butoxypropionamide, N,N-diethyl-β-methoxypropionamide, N,N- Diethyl-β-butoxypropionamide is preferred.

The alkanediol is an alkane compound in which two hydrogen atoms are substituted with two hydroxyl groups, and examples thereof include ethylene glycol, propylene glycol, 2-methyl-1,3-propanediol, 1,2-butanediol, 1, 3-butanediol, 1,4-butanediol, 1,2-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 1,2-heptanediol, 1,2-octanediol, 1,9 -Nonanediol, 1,10-decanediol and the like can be mentioned. Among these, propylene glycol, 1,2-butanediol, 1,3-butanediol, 1,4-butanediol and 1,2-hexanediol are preferable.

The water-based coloring ink and the water-based coating liquid naturally contain water, and examples of water used include pure water such as ion-exchanged water and distilled water, and ultrapure water. Further, when the ink or coating liquid is stored for a long period of time, water sterilized by ultraviolet irradiation or the like may be used in order to prevent the generation of mold and bacteria. Further, it is possible to dilute the ink or coating liquid with water according to the printing conditions of the inkjet printer. In the water-based colored ink and the water-based coating liquid, the water content is preferably in the range of 20 to 80 mass %, for example.

In the above water-based coloring ink and water-based coating liquid, if necessary, a surface conditioner, a defoaming agent, a moisturizer, a wetting and dispersing agent, an antiseptic/antifungal agent, a dissolution aid, an antioxidant, a metal trap agent. Etc. may be appropriately selected and blended within a range not impairing the object of the present invention.

In the ink set of the present invention, the water-based coloring ink and the water-based coating liquid can be prepared by mixing various components appropriately selected as necessary.

The ink set of the present invention can be used in various inkjet printers. Such an inkjet printer is provided with a print head, and the ink and the coating liquid forming the ink set are ejected in the form of droplets from the nozzles of the print head.

Next, a printing method using the ink set of the present invention will be described in detail. For example, a printing method of forming a printing layer having a coating layer and a colored ink layer on a substrate by an inkjet printer using the above-described ink set of the present invention, wherein a water-based coating liquid is discharged from a print head, A step of forming a coating layer by fixing the coating liquid droplets on a substrate, and a step of ejecting a water-based colored ink from a print head to fix the ink droplets on the coating layer to form a colored ink layer And a printing method characterized by including. According to such a printing method, since the droplets of the water-based colored ink are landed on the coating layer obtained from the water-based coating liquid, the aggregation of the pigment in the water-based coloring ink at the portion where the water-based coloring ink comes into contact with the coating layer is prevented. It is possible to suppress the occurrence of bleeding in the colored ink layer, and to form a printing layer having good fixability on a substrate without lowering gloss.

In the above printing method, the base material is not particularly limited, and base materials of various shapes can be selected according to the use of the base material. However, if the ink set of the present invention is used, a sign display can be used. Outdoor articles such as can also be suitably used. The base material may be subjected to a general surface treatment with a primer or the like in order to improve the adhesion to the printed layer.

In the above printing method, the ink droplets of the water-based colored ink can be adhered onto the coating layer without waiting for the coating layer to dry (that is, without drying the coating layer). Therefore, in the above printing method, it is not necessary to perform the drying step of each layer. In the above printing method, the total thickness of the coating layer and the colored ink layer immediately after printing (that is, before evaporation of water or the water-soluble solvent) is preferably in the range of 1 to 20 μm.

Hereinafter, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

<Aqueous coating liquid>
According to the formulation shown in Table 1, a resin, an amine compound, a water-soluble solvent and ion-exchanged water were mixed by a known method to prepare an aqueous coating solution. The pH of each aqueous coating solution is shown in Table 4.

The compounding agents shown in Table 1 below are as follows.
*1 The following was used as the aqueous solution A of the water-soluble polymer having a quaternary ammonium cation: DK6851 (manufactured by Seikou PMC, resin solid content 70% by mass)
*2 Superflex 650 (manufactured by Daiichi Kogyo Seiyaku Co., Ltd., resin solid content: 28% by mass) was used as the aqueous dispersion B of the polymer having a quaternary ammonium cation.
*3 The following was used as the resin aqueous solution C of the styrene-acrylic copolymer: Johncryl 63 (manufactured by BASF, resin solid content 30% by mass)

<Preparation of Polycarbonate Group-Containing Urethane Resin Dispersion D>
In a four-necked flask equipped with a stirrer, a reflux condenser, a thermometer and a nitrogen inlet tube, 100.0 parts by mass of 1,6-hexanediol polycarbonate polyol (average molecular weight 2000), 4.0 parts by mass of neopentyl glycol, Charge 1.0 parts by mass of trimethylolpropane, 10.0 parts by mass of 1,4-cyclohexanedimethanol, 8.0 parts by mass of dimethylolpropionic acid, 0.001 parts by mass of dibutyltin dilaurate and 110.0 parts by mass of methyl ethyl ketone, Mix evenly. Thereafter, 80.0 parts by mass of 4,4′-methylenebis(cyclohexyl isocyanate) was added and reacted at 70° C. for 6 hours to obtain a methyl ethyl ketone solution of a polycarbonate group-containing isocyanate group-terminated urethane resin. The solution was cooled to 40° C. or lower, 6.0 parts by mass of triethylamine was added, and a neutralization reaction was performed at 40° C. for 30 minutes.

Next, the neutralized solution is cooled to 30° C. or lower, and 430.0 parts by mass of water is gradually added using a disper blade to disperse the polycarbonate group-containing isocyanate group-terminated urethane resin neutralized product to obtain a dispersion liquid. Got Then, an amine aqueous solution obtained by dissolving 1.35 parts by mass of diethylenetriamine in 20.0 parts by mass of water was added dropwise to the above dispersion liquid, and further 5.0 parts by mass of a 50% by mass hydrazine aqueous solution was added and reacted for 2 hours. Then, the solvent was removed under reduced pressure at 30° C. to obtain a polycarbonate group-containing urethane resin dispersion D (solid content 35 mass %, average molecular weight 40,000).

<Preparation of Water-based Colored Ink Containing Self-Dispersing Pigment>
According to the formulation shown in Table 2, the self-dispersing pigment aqueous dispersion, the prepared resin dispersion D, the water-soluble solvent, the pH adjusting agent, the surface adjusting agent and the ion-exchanged water are mixed by a known method to form an aqueous coloring ink. Prepared.

<Preparation of non-self-dispersible pigment aqueous dispersion>
According to the formulation shown in Table 3, a mixture of the non-self-dispersible pigment, the water-soluble solvent, the defoaming agent, the wetting/dispersing agent, the pH adjusting agent and the ion-exchanged water was treated with a paint shaker for 15 hours using zirconia beads. "Aqueous colored dispersion containing a non-self-dispersible pigment" was obtained.

<Preparation of Water-based Colored Ink Containing Non-Self-Dispersion Pigment>
The prepared resin dispersion D and a surface modifier were added to the obtained aqueous coloring dispersion containing the non-self-dispersion pigment to obtain an aqueous coloring ink containing the non-self-dispersion pigment.

The compounding agents described in Table 2 above are as follows.
*4 The following were used as the self-dispersible pigment dispersion.
・CAB-O-JET 450C
(Cabot, cyan self-dispersible pigment aqueous dispersion, pigment solid content 10% by mass)
・CAB-O-JET-265M
(Cabot, magenta self-dispersible pigment aqueous dispersion, pigment solid content 15% by mass)
・CAB-O-JET 270Y
(Cabot, yellow self-dispersible pigment aqueous dispersion, pigment solid content 10% by mass)
・CAB-O-JET 352K
(Cabot, black self-dispersible pigment aqueous dispersion, pigment solid content 20% by mass)
*5 TSF4446 (polyether-modified silicone oil manufactured by Momentive)
The compounding agents listed in Table 3 above are as follows.
*5 TSF4446 (polyether-modified silicone oil manufactured by Momentive)
*6 The following were used as non-self-dispersion pigments.
・Phthalocyanine blue (FASTOGEN Blue FA5380 (DIC), cyan)
・Dichloroquinacridone (Shinkasha Magenta RT (manufactured by BASF), Magenta)
・Quinoxalinedione (Hostaperm Yellow H5G (Clariant), yellow)
・Carbon black (Nerox-1000 (made by Orion Engineered Carbon), black)
*7 SN deformer 1312 (manufactured by San Nopco Co., Ltd.)
*8 Wetting dispersant (Neugen EA-157, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.)

An ink set comprising a combination of a water-based coloring ink and a water-based coating liquid was prepared and various evaluations were performed. Table 4 shows combinations of the water-based coloring ink and the water-based coating liquid.

<Bleeding during printing>
Using Ramito PJ-1304NX manufactured by Muto Kogyo Co., Ltd., first, the coating liquid was discharged onto the surface of the vinyl chloride sheet and solid printing was performed to form a coating layer. Next, without drying the coating layer, an image defined by JIS X9201 2001 N3A was printed on the coating layer with a water-based coloring ink, and the degree of bleeding was visually evaluated.
○: No blurring ×: Blurring

<Adhesiveness>
Using Ramito PJ-1304NX manufactured by Muto Kogyo Co., Ltd., first, the coating liquid was discharged onto the surface of the vinyl chloride sheet and solid printing was performed to form a coating layer. Next, without drying the coating layer, a water-based colored ink was ejected onto the coating layer to perform solid printing. A cellophane tape (registered trademark, manufactured by NICHIBAN Co., Ltd.) having a width of 24 mm was brought into close contact with the printed portion, and then the tape was peeled off, and the state of the peeled portion was visually evaluated according to the following evaluation criteria.
◯: Not peeled off ×: Partly peeled off

<Gloss>
First, a coating liquid was discharged onto the surface of the white vinyl sheet by using Ramirez PJ-1304NX manufactured by Muto Kogyo Co., Ltd., and solid printing was performed to form a coating layer. Next, without drying the coating layer, a water-based colored ink was ejected onto the coating layer to perform solid printing. The gloss value of the printed portion was measured at 20° by using a gloss meter micro-TRI-gloss manufactured by BYK.
◯: 20° gloss value is 20 or more.
X: 20° gloss value is less than 20.

<Corrosion>
The print head used for the Ramito PJ-1304NX manufactured by Muto Kogyo Co., Ltd. was dipped in the coating liquid and the colored ink for 1 week, and the change in the vicinity of the nozzle from which the droplet was ejected was observed with a microscope. Corrosion was confirmed in the coating liquid 4. (Evaluation result: ×). Corrosion did not occur with the remaining coating liquid and colored ink (evaluation result: ◯).

Claims (5)

An ink set comprising a water-based coloring ink and a water-based coating liquid,
The water-based colored ink contains water, a self-dispersible pigment, a water-soluble solvent and a resin, the water-based coating liquid contains water, a water-soluble solvent and a resin, the resin contained in the water-based coating liquid is quaternary includes a water-soluble polymer having an ammonium cation, pH of the aqueous-based coating solution Ri near the range of 7.1 to 10.0, wherein the water-based coating liquid, the boiling point as a pH adjusting agent 70 to 270 ° C. An ink set comprising an amine compound that is The ink set according to claim 1, wherein in the water-based coating liquid, the proportion of the water-soluble polymer having a quaternary ammonium cation in the resin is 50% by mass or more. The water-soluble solvent contained in the water-based coloring ink and the coating liquid contains at least one selected from the group consisting of glycol ethers, lactone compounds having a 3- to 5-membered ring, amide compounds, and alkanediols. Ink set described in. Any of claims 1 to 3, wherein the amine compound is at least one selected from the group consisting of N-methyldiethanolamine, N-ethyldiethanolamine, N,N-dimethylethanolamine, and N,N-diethylethanolamine. 2. The ink set according to item 1. A claim 1 printing method the print layer is formed on a substrate and a coating layer and the colored ink layer by an ink jet printer using the ink set according to any one of 4,
A step of ejecting the aqueous coating liquid from a print head to form a coating layer by depositing coating droplets on a substrate; and ejecting the aqueous color ink from the print head to coat the ink droplets with the coating liquid. Forming a colored ink layer by depositing on the layer.