JP5703544B2 - Water-based ink composition - Google Patents

Description

  The present invention relates to a water-based ink capable of printing images and characters excellent in abrasion resistance, ethanol resistance, water resistance and the like on the surface of a non-absorbing substrate such as a polyvinyl chloride sheet.

Conventionally, gravure printing for soft packaging materials, flexographic printing for sanitary, silk screen printing for metal plates, inkjet printing for indoor and outdoor advertising, etc. are generally known as printing methods for non-absorbent substrates.

  In particular, in inkjet printing, in which images and characters are printed using minute ink droplets ejected from the nozzles of an inkjet head, printers that can handle A-0 size have been developed in recent years. Due to the increasing use environment, ink jet printing inks having excellent water resistance, weather resistance, and friction resistance have been actively developed.

  In particular, in inkjet printing inks used for the sign industry, pigment-based solvent inkjet inks that use organic solvents as solvents instead of water-based inkjet inks in which colorants such as water-soluble dyes are added to general water. Mainly used. This requires the ability to print directly on the surface of a non-absorbent substrate such as a polyvinyl chloride sheet, which is used as a medium for outdoor advertising and the like. It is considered that a pigment ink composition containing a binder resin that adheres firmly to the surface of the absorbent substrate and an organic solvent that can dissolve the binder resin or the surface of the non-absorbable substrate is considered suitable. It is.

  However, the long-term use of a solvent is not preferable because there are environmental problems such as VOC and harmful problems such as acute toxicity, mutagenicity, carcinogenicity, and reproductive toxicity. Therefore, at present, the development of water-based inkjet ink using a pigment as a colorant is underway (Patent Document 1).

However, although the developed water-based ink-jet ink can be directly printed on an absorbent substrate such as paper, it cannot be printed directly on the surface of the non-absorbent substrate. This is because, when a water-soluble solvent capable of dissolving the surface of the non-absorbing substrate is added to the water-based ink, the performance of eroding the substrate surface is greatly reduced. Since it deteriorates and the printed matter resistance is weak, it is currently not used for outdoor advertising (Patent Document 2).

JP-A-11-183920 Japanese Patent No. 4148424

This invention is made | formed in view of the said subject, The objective uses the high-boiling water-soluble solvent which melt | dissolves the plasticizer in a non-absorbing base material, and the solubility parameter value of the mixed solution of a solvent and water ( By making δ) closer to the plasticizer solubility parameter value (δ), it is possible to print directly not only on absorbent substrates such as paper, but also on non-absorbent substrates. An object of the present invention is to provide a water-based ink composition, particularly an ink-jet ink composition, using a pigment that realizes a printed material resistance superior to that of a printed material and has good printing stability.

The above object of the present invention is achieved by the following configurations.

At least a pigment, water, a water-soluble organic solvent having a boiling point higher than water and a binder resin,
Furthermore, the solubility parameter value (δ) of the mixed liquid obtained by mixing water and the solvent is 17 to 20 ,
Furthermore, a water-soluble organic solvent having a boiling point higher than water is
A water-soluble organic solvent solubility parameter value ([delta]) = 10 to 30, and one or more monoalkyl ether solvent having one terminal hydroxyl group,
Solubility parameter value (δ) = 10-30 water-soluble organic solvent, one or more dialkyl ether solvents having alkyl groups at both ends ,
Solubility parameter value nitrogen-containing or sulfur-containing or lactone-based ([delta]) = 15-25 non-absorbable printing water-based ink-jet ink compositions and one or more solvents, wherein the free Mukoto of.

Furthermore, a water-based ink composition characterized by using a water-based resin emulsion or a water-soluble polymer compound as a binder resin.
Furthermore, the water-based ink composition which is an inkjet ink.
Furthermore, it is related with the water-based ink composition which is the inkjet ink for non-absorbing base-material printing.

  According to the present invention, a high-boiling water-soluble solvent having good plasticizer solubility in the non-absorbing substrate is used, and the solubility parameter value (δ) of the mixed solution of the solvent and water is determined as the solubility parameter value of the plasticizer. By approaching (δ), it is possible to print directly not only on absorptive substrates such as paper but also on non-absorbent substrates, and realizes printed material resistance superior to that printed with solvent ink. In addition, an aqueous ink composition, particularly an inkjet ink composition, using a pigment with good printing stability is provided.

  The ink composition of the present invention comprises at least a pigment excellent in weather resistance, a binder resin that firmly adheres the pigment to the surface of the non-absorbable printing medium, a water-soluble organic solvent having a boiling point equal to or higher than water, and water. It is an aqueous pigment ink composition. The organic solvent used in the present invention is preferably a water-soluble organic solvent having a boiling point higher than that of water. When the boiling point is lower than that of water, when used as an ink-jet ink, drying on the ink-jet head nozzle is accelerated, which causes clogging.

Furthermore, the solubility parameter value of the mixture obtained by mixing a water-soluble organic solvent having a boiling point above water and water ([delta]) has been calculated by the method of Hansen, is that the value is 17-20 Most preferred. This is a mixture of water and a solvent mixed with the solubility parameter value (δ = 18.24) of bis (2-ethylhexyl) phthalate, which is most commonly used as a plasticizer for non-absorbing substrates. By approaching the solubility parameter value (δ), the surface of the base material is slightly dissolved by the solvent eroding the plasticizer contained in the non-absorbing base material, even though it is not corrosive to the printer. This is because a water-based ink composition having good adhesion to the non-absorbent substrate of the ink coating can be prepared.
Hansen's method is calculated using the following calculation formula with reference to page 68 of “Solubility Parameter Application Examples-Based on Mechanisms and Evaluation / Calculation Examples of Solubility” published by Information Technology Corporation. It was.

  The water-soluble organic solvent having a boiling point higher than that of water preferably has a solubility parameter value (δ) of 10-30. When the solubility parameter value (δ) of the water-soluble solvent to be used is 10 or less, there is no solvent that dissolves in water, and when it is 30 or more, the surface of the non-absorbent substrate is not corroded.

The water-soluble organic solvent having a boiling point equal to or higher than water having a solubility parameter value (δ) of 10 to 30 is an alcohol solvent such as butyl alcohol or 1,3-propanediol, or a nitrogen-containing or sulfur-containing solvent. It is preferable to include any one or more of a lactone solvent or a solvent represented by the general formula (1).
R ₁ (OR ₂ ) _Z OR ₃ (1)
(In the formula, R ₂ represents an ethylene group or a propylene group, R ₁ and R ₃ each independently represents a hydrogen atom or an alkyl group having 1 to 6 carbon atoms, and Z represents an integer of 1 to 6).

  Examples of the organic solvent corresponding to the solubility parameter value (δ) = 10 to 30 in the general formula (1) include glycols such as ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, and dipropylene glycol, ethylene glycol monobutyl ether, Propylene glycol monomethyl ether, propylene glycol n-propyl ether, propylene glycol monobutyl ether, diethylene glycol monoethyl ether, diethylene glycol diethyl ether, diethylene glycol monobutyl ether, diethylene glycol dibutyl ether, diethylene glycol methyl ethyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl Ether, dipropylene glycol Glycol monopropyl ether, dipropylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl ether, triethylene glycol monobutyl ether, tripropylene glycol monomethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, etc. There is kind.

  Further, one or more solvents having a solubility parameter value (δ) = 10 to 30 represented by the general formula (1) and a solubility parameter value (δ) = 15 in a nitrogen-containing system, a sulfur-containing system, or a lactone system. It is preferred to include one or more of ˜25 solvents.

  Examples of organic solvents corresponding to solubility parameter values (δ) = 15 to 25 in nitrogen-containing, sulfur-containing, or lactone solvents include 3-methyloxazolidinone, 3-ethyloxazolidinone, 2-pyrrolidone, and 1-methyl-2. There are -pyrrolidone, 1-ethyl-2-pyrrolidone, γ-butyrolactone, γ-butyrolactam, ε-caprolactone, ε-caprolactam, δ-valerolactone, δ-valerolactam, dimethyl sulfoxide and β-alkoxypropionamides.

  Further, the solvent represented by the general formula (1) may include one or more monoalkyl ether solvents having one terminal hydroxyl group and one or more dialkyl ether solvents having both terminal alkyl groups. preferable. This includes a monoalkyl ether solvent having a single-end hydroxyl group that has a high boiling point and can adjust the viscosity of the ink, and a dialkyl that has a high boiling point and a double-end alkyl group that is excellent in erosion performance to a plasticizer in a non-absorbing substrate. A water-based ink composition that can be applied to various ink jet heads by using an ether-based solvent together, is excellent in printing stability without being dried on the ink jet head nozzle, and can realize excellent adhesion to a non-absorbing substrate. Can be created.

  Further, if the solubility parameter of a monoalkyl ether solvent having a hydroxyl group at one end is (δa) and the solubility parameter of a dialkyl ether solvent having an alkyl group at both ends is (δb), then | δa−δb | = 2 It is preferably ˜15, and most preferably | δa−δb | = 3-10. When 0 ≦ | δa−δb | <2, the properties of the monoalkyl ether solvent and the dialkyl ether solvent are similar, so that the erosion performance of the plasticizer in the non-absorbing substrate is excellent, and the ink jet head It is not possible to make water-based ink that does not dry in Further, if | δa−δb |> 15, the solubility in water is poor, and separation is not preferable.

  As the binder resin excellent in adhesion to the surface of the non-absorbable printing medium used in the present invention, a water-insoluble resin emulsion or a water-soluble polymer compound is preferable, and a water-insoluble resin emulsion is most preferable. The reason why water-insoluble resin emulsions are most preferred is that they can produce inks with low viscosity while having high resin solids, so the ink coating has good resistance and ejection performance from the inkjet head. That's why.

  As the water-insoluble resin emulsion, a vinyl chloride resin emulsion, an acrylic resin emulsion, and a polypropylene resin emulsion are preferable, and an emulsion obtained by an emulsion polymerization method is most preferable. It is possible to emulsify a high molecular weight, low acid value vinyl chloride resin with a high solid content by using an emulsification dispersion method. An emulsion obtained by a phase inversion emulsification method or an emulsification dispersion method can be used. This is because the adhesion and resistance of the ink coating to the surface of the non-absorbable print medium that cannot be satisfied by the used ink can be realized. Specific examples include Vinibrand 271 manufactured by Nissin Chemical Co., Ltd., ViniBran 278, ViniBran 603, ViniBran 690, ViniBran 900, ViniBran 902, ViniBran 985, UCAR AW-875 manufactured by Dow Chemical Company, and Super Clone E-480T manufactured by Nippon Paper Chemicals. , Supercron E-503, Supercron E-604, Supercron S-4249, Auroren AE-301, and Auroren S-6097. The resin is preferably contained in the ink in an amount of 0.1 to 40% by weight, and particularly preferably 3.0 to 30% by weight. If the addition amount is 0.1% by weight or less in the ink, the adhesion to the surface of the printing medium is poor, and the resistance of the coating film is reduced. If the addition amount is 40% by weight or more, the ink viscosity is too high. Since it falls, it is not preferable.

  As the pigment used in the present invention, various pigments used in printing inks, paints and the like can be used. When these pigments are represented by color index, Pigment Black 7, Pigment Blue 15, 15: 1, 15: 3, 15: 4, 15: 6, 60, Pigment Green 7, 36, Pigment Red 9, 48, 49 , 52, 53, 57, 97, 122, 149, 168, 177, 178, 179, 206, 207, 209, 242, 254, 255, pigment violet 19, 23, 29, 30, 37, 40, 50, pigment Yellow 12, 13, 14, 17, 20, 24, 74, 83, 86, 93, 94, 95, 109, 110, 117, 120, 125, 128, 137, 138, 139, 147, 148, 150, 151 , 154, 155, 166, 168, 180, 185, 213, Pigment Orange 36, 43, 51, 5 , Such as 59,61,71,74, and the like. As for carbon black, any carbon black such as neutral, acidic and basic can be used. The pigment is desirably contained in the ink in an amount of 0.1 to 10% by weight.

  The ink composition of the present invention can use various additives such as a plasticizer, a surface conditioner, an ultraviolet light inhibitor, a light stabilizer, an antioxidant, a hydrolysis inhibitor, an activator, and a dispersant.

  Examples of the printing method of the ink composition of the present invention include gravure printing, flexographic printing, silk screen printing, inkjet printing, and the like, and an inkjet printing method is particularly preferable.

The ink composition of the present invention is prepared by first dispersing a pigment in water or a water-organic solvent mixed solvent using a paint shaker, a sand mill, a roll mill, a medialess disperser, or the like. It is manufactured by diluting with the water, organic solvent and binder resin of the invention.

  EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not particularly limited to the examples. In the examples, “parts” and “%” represent “parts by weight” and “% by weight”.

[Production Example 1]
(Production of aqueous dispersion 1)
Crude copper phthalocyanine (copper phthalocyanine manufactured by Toyo Ink Manufacturing Co., Ltd.): 250 parts, sodium chloride: 2500 parts, and polyethylene glycol 300 (manufactured by Tokyo Chemical Industry Co., Ltd.): 160 parts were charged into a 1 gallon kneader (manufactured by Inoue Seisakusho Co., Ltd.) made of styrene. Kneaded for 4 hours. Next, this mixture was poured into 2.5 liters of warm water and stirred for about 1 hour with a high speed mixer while being heated to about 80 ° C. to form a slurry, followed by repeated filtration and washing 5 times to obtain sodium chloride and An aqueous pigment dispersion (treated pigment dispersion) having a solid content of 50% was obtained by removing the solvent.

  Aqueous pigment dispersion (treated pigment dispersion, solid content 50% product): 30.0 parts, acrylic resin aqueous solution (Johnson Polymer 62 “John Crill 62” solid content 34.6%): 3.0 parts, dispersion Agent ("Emulgen 420" manufactured by Kao Co., Ltd .: 2.0 parts, purified water: 50.0 parts, 6.0 parts of glycerin are placed in a sand mill and dispersed for 4 hours, and then filtered through membrane filters of 1 μm and 0.45 μm. Thus, an aqueous pigment dispersion 1 was obtained.

[Production Example 2]
(Production of aqueous dispersion 2)
In place of the crude copper phthalocyanine of Production Example 1, 260 parts of a yellow pigment (“Poster Palm Yellow H3G” manufactured by Hoechst) was used to prepare an aqueous pigment dispersion 2 in the same procedure as in Production Example 1.

[Production Example 3]
(Production of aqueous dispersion 3)
Red pigment (“Poster Palm Pink E” manufactured by Hoechst): 250 parts, sodium chloride: 2500 parts, and polyethylene glycol 300 (manufactured by Tokyo Chemical Industry Co., Ltd.): 160 parts are charged into a 1 gallon kneader (manufactured by Inoue Seisakusho) made of styrene. Kneaded for 3 hours. Next, this mixture was poured into 2.5 liters of warm water and stirred for about 1 hour with a high speed mixer while being heated to about 80 ° C. to form a slurry, followed by repeated filtration and washing 5 times to obtain sodium chloride and An aqueous pigment dispersion (treated pigment dispersion) having a solid content of 50% was obtained by removing the solvent.

  Aqueous pigment dispersion (treated pigment dispersion, solid content 50% product): 30.0 parts, acrylic resin aqueous solution (Johnson Polymer 62 “John Crill 62” solid content 34.6%): 3.0 parts, dispersion Agent ("Emulgen 420" manufactured by Kao Co., Ltd .: 2.0 parts, purified water: 50.0 parts, 6.0 parts of glycerin are placed in a paint shaker and dispersed for 4 hours, and then filtered through membrane filters of 1 μm and 0.45 μm. Thus, an aqueous pigment dispersion 3 was obtained.

[Examples 2-5, 10, 11, 14, 15] Comparative Examples 1-3]
The raw materials described in Table 1 were used as ingredients, mixed by stirring with a high speed mixer, and then filtered with 1 μm and 0.45 μm membrane filters to obtain an aqueous inkjet ink 1.

Abbreviations in Table 1 are as shown below.
NMP: 1-methyl-2-pyrrolidone NEP: 1-ethyl-2-pyrrolidone GBL: γ-butyrolactone ε-CL: ε-caprolactone MOZ: 3-methyloxazolidinone EOZ: 3-ethyloxazolidinone DMI : 1,3-dimethyl-2-imidazolidinone, BTG: triethylene glycol monobutyl ether, BDG: diethylene glycol monobutyl ether, BEG: ethylene glycol monobutyl ether, MFG: propylene glycol monomethyl ether, MFDG: dipropylene glycol monomethyl ether, MFTG : Tripropylene glycol monomethyl ether, PFG: Propylene glycol monopropyl ether, PNP: Propylene glycol n-propyl ether, DPNP: Dipropylene glycol monopropyl ether, DMTG: Tri Chi glycol dimethyl ether · DMDG: diethylene glycol dimethyl ether
DMTeG: Tetraethylene glycol dimethyl ether

As can be seen from Table 2 , Examples 2 to 5 were added to the ink with a water-soluble organic solvent having a boiling point equal to or higher than that of water specified in the present invention and a solubility parameter value (δ) = 10-30 . The ink compositions 10 , 11, 14, and 15 are not only capable of printing directly on a non-absorbent substrate such as an untreated polyvinyl chloride resin sheet, but also a plasticizer in the printed substrate. By dissolving the ink and creating an ink coating film, the printed matter resistance, ethanol resistance, water resistance and abrasion resistance are all excellent. In particular, Examples 2 to 5 have not only printed matter resistance but also high glossiness of the ink coating film, and do not dry on the inkjet head at the time of printing, so that the printing stability is also excellent.

  As the water-soluble organic solvent used in Comparative Examples 1 to 3, glycerin generally used in water-based inkjet inks was used. When this was converted into an ink with a different ratio and the same evaluation was performed, the surface of the polyvinyl chloride resin sheet, which is a non-absorbent base material, cannot be eroded by being mixed with water. The result was inferior. Since this is an organic solvent having a solubility parameter value (δ) of glycerin itself of 30 or more, the solubility parameter value (δ) of the mixed solution of the organic solvent and ion-exchanged water is generally applied to the polyvinyl chloride resin sheet. This is because the solubility parameter value (δ) of bis (2-ethylhexyl) phthalate, a plasticizer used in general, cannot be brought close to 18.24.

The evaluation method is shown below.

<Alcohol resistance>
With respect to the ink compositions obtained in Examples 2 to 5, 10, 11, 14, 15, and Comparative Examples 1 to 3, the surface was not observed with Hi-Fi JET PRO II Model FJ-540 (Roland DG). Solid printing with a printing rate of 100% was performed on the treated polyvinyl chloride resin sheet, and the printed surface was evaluated for alcohol resistance with a rubbing tester (model AB301, manufactured by Tester Sangyo). As evaluation conditions, a test cloth (gold width 3) diluted with ethanol / water = 70/30 was dropped and applied at a load of 500 g, 50 reciprocations, and the coated surface was not peeled off at all. No. 5, coloring was observed on the test cloth, but no noticeable change was observed on the printed surface, no coloring was observed on the printed surface, and no slight color fading was observed on the printed surface. The case where the substrate was seen after being peeled off was evaluated as 2, and the case where the ink was peeled off and the substrate was seen more than half was evaluated as 1.

<Water resistance>
With respect to the ink compositions obtained in Examples 2 to 5, 10, 11, 14, 15, and Comparative Examples 1 to 3, the surface was not observed with Hi-Fi JET PRO II Model FJ-540 (Roland DG). Solid printing with a printing rate of 100% was performed on the treated polyvinyl chloride resin sheet, and the printed surface was evaluated for water resistance with a rubbing tester (model AB301, manufactured by Tester Sangyo). As an evaluation condition, a drop of water was dropped on a test cloth piece (gold width 3), the load was 500 g, 50 reciprocations were carried out, the coated surface was not peeled off at all, and the test cloth piece was colored. Although it was seen, the printed surface showed no noticeable change 4, the test piece was colored, and the printed surface was slightly discolored 3, but it was peeled off but the substrate was visible 2 was evaluated as 1 and the ink was peeled off and the substrate could be seen more than half.

<Abrasion resistance>
With respect to the ink compositions obtained in Examples 2 to 5, 10, 11, 14, 15, and Comparative Examples 1 to 3, the surface was not observed with Hi-Fi JET PRO II Model FJ-540 (Roland DG). Solid printing with a printing rate of 100% was performed on the treated polyvinyl chloride resin sheet, and the printed surface was evaluated for rubbing resistance with a rubbing tester (Model AB301, manufactured by Tester Sangyo). Evaluation conditions were as follows: test cloth piece (gold width 3), load 1000g, 50 reciprocations, the coated surface was not peeled off at all, and the test cloth piece was colored. 4 shows no noticeable change, 3 is colored on the test piece and 3 is slightly discolored on the printed surface, 2 is peeled but the substrate is visible, 2 is ink. A value of 1 was taken when the substrate was seen more than half.

<Glossy>
With respect to the ink compositions obtained in Examples 2 to 5, 10, 11, 14, 15, and Comparative Examples 1 to 3, the surface was not observed with Hi-Fi JET PRO II Model FJ-540 (Roland DG). Solid printing with a printing rate of 100% was performed on the treated polyvinyl chloride resin sheet, and the glossiness was measured with a 60 ° gloss meter.
<Printing stability>
About the ink composition obtained in Examples 2-5, 10, 11, 14, 15, and Comparative Examples 1-3, it is made into Hi-Fi JET PRO II Model FJ-540 (made by Roland DG) in a 25 degreeC environment. Then, the surface was continuously printed on an untreated polyvinyl chloride resin sheet for 2 hours, and the occurrence frequency of dot omission, flight bending or ink scattering was evaluated. In the table, a nozzle check pattern was printed after continuous printing for 2 hours, and the number of missing dots, flying curves or ink splatters was confirmed, and the number was described.

Claims (2)

At least a pigment, water, a water-soluble organic solvent having a boiling point higher than water and a binder resin,
Furthermore, the solubility parameter value (δ) of the mixed liquid obtained by mixing water and the solvent is 17 to 20 ,
Furthermore, a water-soluble organic solvent having a boiling point higher than water is
A water-soluble organic solvent solubility parameter value ([delta]) = 10 to 30, and one or more monoalkyl ether solvent having one terminal hydroxyl group,
Solubility parameter value (δ) = 10-30 water-soluble organic solvent, one or more dialkyl ether solvents having alkyl groups at both ends ,
Solubility parameter value nitrogen-containing or sulfur-containing or lactone-based ([delta]) = 15-25 non-absorbable printing water-based ink-jet ink compositions and one or more solvents, wherein the free Mukoto of. Further, as the binder resin, non-absorbable printing water-based ink jet ink composition according to claim 1, characterized by using an aqueous resin emulsion or a water-soluble polymer compound.