JP2016190930A - Pigment printing ink and inkjet printing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide pigment printing ink having both good fixability onto a fabric and good image density.SOLUTION: There is provided pigment printing ink containing a pigment, water and a water-soluble organic solvent, where the pigment is dispersed by a pigment dispersing agent, the pigment dispersing agent is neutralized by volatile amine and an inorganic base, the pigment dispersing agent is neutralized by a mixed base where the volatile amine and the inorganic base are in a range of 9:1 to 1:4, and pigment ink for inkjet printing preferably further contains a fixing resin.SELECTED DRAWING: None

Description

  The present invention relates to a textile inkjet ink used for textile printing by the inkjet recording method, and a method for producing a printed matter using the same.

  As a method for printing images such as letters, pictures, designs, etc. on fabrics such as textiles and non-woven fabrics, in addition to screen printing methods and roller printing methods, in recent years, printing that can be printed in a substantially plateless manner by image processing with a computer. Inkjet methods are attracting attention.

  In addition, the textile inkjet method is also attracting attention as a technology for reducing the environmental load because the problem of wastewater treatment is reduced as compared with the conventional textile printing method.

  In addition, as a printing ink jet method, a method of printing with a dye ink containing a dye as a colorant and a pigment ink containing a pigment is known.

  When a pigment is used as a color material, there are advantages such as high light resistance, compatibility with a plurality of fiber types, and the absence of a color material removal step, and its simplicity is preferred. In order to fix the pigment, it is known to add a binder component having a fixing function to the fabric to the ink. The ink contains a fixing resin, the pretreatment agent contains the fixing resin, or the dispersion. A method of using an agent as a fixing resin is known.

  In textile printing inks using pigments as color materials, an anionic dispersant having an anionic group such as a carboxyl group, a sulfonic acid group, a sulfuric ester group, or a phosphoric acid group as a pigment dispersant or polyethylene for the purpose of improving dispersion stability It is known to disperse a pigment by a dispersing agent such as a nonionic dispersing agent having a hydrophilic group such as an exhaust or a polyol. It is known that an anionic dispersant can further improve the dispersion stability by ionizing an anionic group. Patent Documents 1 to 3 disclose that an anionic dispersant is an amine or a metal salt as a neutralization salt. A neutralized pigment printing ink is disclosed.

JP 2005-206797 A JP 2003-268271 A International Publication No. 2014/084161

  As a result of further technical studies by the inventors, the neutral base of the anionic dispersant can be an amine or ammonia as a volatile base, so that a good dispersant can be maintained until the amine is volatilized, and It has been found that a textile printing pigment ink having a high image density can be obtained by reducing the dispersion stability of the pigment by volatilizing the amine by heating the fabric or the like to thereby keep the pigment on the fabric surface.

  However, the pigment printing ink in which the anionic dispersant is neutralized only with the amine significantly reduces the dispersion stability of the pigment due to the volatilization of the amine, so that the image density is improved, but the pigment is easily peeled off from the fabric and is durable. It became clear that it was not preferable from the viewpoint of sex.

  The present invention has been made in view of the above problems, that is, the object thereof is to provide a pigment printing ink having both good fixability to a fabric and good image density.

  The above object of the present invention is achieved by the following present invention. That is, the present invention uses an anionic dispersant as a dispersant for printing pigment inks and neutralizes with a mixed base of a volatile base composed of amine or ammonia and a non-volatile base composed of an inorganic base as a neutralizing base of the anionic dispersant. A pigment printing ink having a pigment, water and a water-soluble organic solvent.

  According to the present invention, a pigment printing ink having both good fixability to a fabric and good image density is provided.

  Although the reason why the pigment printing ink and the printing method capable of achieving the object of the present invention can be provided by the configuration of the present invention is not clear, the present inventors presume that the reason is as follows.

  When the pigment printing ink landed on the fabric is heated, amine or ammonia as a volatile base is volatilized, and the dispersion stability of the pigment is lowered, and the pigment is agglomerated on the fabric surface. At this time, the pigment neutralized with only the volatile amine loses the electric charge in the dispersant and changes from a hydrophilic state to a hydrophobic state. On the other hand, the water in the ink droplets is volatilized by heating, and the amount of the water-soluble organic solvent is relatively increased, so that interfacial separation consisting of a water layer and an oil layer occurs at a micro level inside the ink droplet. When interfacial separation occurs, the water-soluble organic solvent has a specific gravity lower than that of water, so that phase separation is performed so that a water layer is formed at the bottom and a water-soluble organic solvent layer is formed at the top. Since the pigment that has lost its charge is oleophilic and goes to the oil layer, the pigment is present on top of the finished image coating. For this reason, color fading easily occurs during washing, leading to a decrease in fastness and scratch resistance.

  On the other hand, in the case of the pigment printing ink of the present invention, even if amine or ammonia as a volatile base volatilizes, some anionic groups of the pigment dispersant do not volatilize but exist as counter anions. The entire pigment has a charge. Therefore, even if interface separation between the water layer and the oil layer occurs, the pigment can remain in the water layer. Therefore, the pigment can be fixed to the lower part of the coating film in the vicinity of the fabric, and a fabric having good image density and fastness can be formed.

  As a result, while the pigment is fixed in the vicinity of the fabric or on the surface of the fabric fiber, it is well fixed by the pigment fixing resin, so that both high fastness and high image density can be achieved.

  Furthermore, in the present invention, it is preferable to use a fixing resin in combination, and the effect of the present invention is manifested more significantly by fixing the pigment using a water-dispersible fixing resin such as latex or a water-soluble fixing resin. Can do.

  Preferred configurations / embodiments of the present invention are disclosed below, but the present invention is not limited to the following description. In the present invention, when a numerical range is described using “to”, the upper limit and the lower limit are included.

(Pigment printing ink)
The pigment printing ink of the present invention is a pigment printing ink containing a pigment, water, and a water-soluble organic solvent, the pigment is dispersed by a pigment dispersant, and the pigment dispersant is formed by a volatile amine and an inorganic base. A pigment printing ink characterized by being neutralized. The ink according to the present invention will be described in detail below.

(Pigment)
There is no particular limitation on the pigment that can be used in the present invention. However, it is preferable to use a pigment having a weight average particle diameter in the range of 50 to 200 nm from the viewpoints of storage stability, ejection properties, and image density as an inkjet ink.

  Examples of pigments include insoluble azo pigments such as toluidine red, toluidine maroon, Hansa yellow, benzidine yellow and pyrazolone red, soluble azo pigments such as ritole red, heliobordeaux, pigment scarlet and permanent red 2B, alizarin, indanthrone and Derivatives from vat dyes such as thioindigo maroon, phthalocyanine organic pigments such as phthalocyanine blue and phthalocyanine green, quinacridone organic pigments such as quinacridone red and quinacridone magenta, perylene organic pigments such as perylene red and perylene scarlet, isoindo Isoindolinone-based organic pigments such as linone yellow and isoindolinone orange, and pylanthrone such as pyranslon red and pyranslon orange Organic pigments such as organic pigments, thioindigo organic pigments, condensed azo organic pigments, benzimidazolone organic pigments, quinophthalone organic pigments such as quinophthalone yellow, and isoindoline organic pigments such as isoindoline yellow, and flavanthron yellow, Inorganic pigments such as acylamide yellow, nickel azo yellow, copper azomethine yellow, perinone orange, anthrone orange, dianthraquinonyl red, dioxazine violet, carbon black, titanium oxide and calcium carbonate are included.

  In the ink according to the present invention, the pigment described above is preferably dispersed by a pigment dispersant described below.

  In the ink according to the present invention, the pigment content is preferably 0.5 to 10% by mass.

(Pigment dispersant)
The pigment dispersant that can be used in the present invention has a glass transition temperature of 0 to 80 ° C., an acid value of 100 to 300 mgKOH / g, a mass average molecular weight of 5,000 to 30,000, and a pKa of 5 to 8. A polymer dispersant obtained by neutralizing an anionic resin with a basic compound containing a volatile amine and an inorganic base described below can be used. Examples of the anionic resin include carboxyl group-containing unsaturated compounds such as acrylic acid, methacrylic acid, itaconic acid, maleic acid, maleic anhydride, maleic acid monoalkyl ester, citraconic acid, citraconic anhydride, and citraconic acid monoalkyl ester. One or more monomers (including acid anhydride group-containing unsaturated monomers that open to give carboxyl groups) and styrene monomers such as styrene, α-methylstyrene, vinyltoluene Aralkyl methacrylate or acrylate such as benzyl methacrylate, benzyl acrylate, methyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, methyl acrylate, butyl acrylate, 2-ethylhexyl Reaction with one or more unsaturated monomers selected from alkyl methacrylates or acrylates such as acrylate, stearyl acrylate, lauryl acrylate, etc. (preferably methacrylates or acrylates having alkyl having 1 to 18 carbon atoms) The resulting copolymer can be used.

  Specific examples of this copolymer include (meth) acrylic acid alkyl ester- (meth) acrylic acid copolymer, styrene- (meth) acrylic acid copolymer, styrene- (meth) acrylic acid- (meth) acrylic. Acid alkyl ester copolymer, styrene-maleic acid- (meth) acrylic acid alkyl ester copolymer, styrene-maleic acid half ester copolymer, styrene-maleic acid half ester- (meth) acrylic acid alkyl ester copolymer, Examples thereof include styrene- (meth) acrylic acid- (meth) acrylic acid alkyl ester-benzyl (meth) acrylate copolymer.

(Basic compound)
The pigment dispersant contained in the ink of the present invention is neutralized with a volatile amine and an inorganic base. The volatile amine and inorganic base that can be used in the present invention will be described in detail.

(Volatile amine)
The amine that can be used in the present invention is neutralized with a volatile amine having a boiling point of less than 200 ° C., whereby the amine is easily volatilized during drying, and the hydrophobicity can be increased quickly. More preferably, it is neutralized with a volatile amine of less than 100 ° C.

  Examples of amines that can be used in the present invention include ammonia, triethylamine, 2-dimethylaminoethanol, 2-di-n-butylaminoethanol, methyldiethanolamine, 2-amino-2-methyl-1-propanol, diethanolamine, Triethanolamine, 2-methylaminoethanol and the like can be preferably used.

(Inorganic base)
Examples of the inorganic base that can be used in the present invention include alkali metal or alkaline earth metal hydroxides.

  Examples of the alkali metal hydroxide include lithium hydroxide, sodium hydroxide, and potassium hydroxide.

  Examples of the alkaline earth metal hydroxide include beryllium hydroxide, magnesium hydroxide, calcium hydroxide, and strontium hydroxide.

  Among inorganic bases, alkali metal hydroxide is preferable, and lithium hydroxide and sodium hydroxide are particularly preferable.

  In the present invention, the mixed base composed of a volatile amine and an inorganic base is preferably contained so as to be 80% to 120% of the neutralization equivalent of the pigment dispersant, and more preferably within the range of 90% to 105%. It is.

  The ratio of the volatile amine and the inorganic base that neutralizes the pigment dispersant is preferably 9: 1 to 1: 4, and more preferably 4: 1 to 1: 1.

(Water-soluble organic solvent)
The ink of the present invention contains a water-soluble organic solvent. In the present invention, the type and amount of the water-soluble organic solvent may be appropriately adjusted from the viewpoints of ejection stability, permeability, gelation rate adjustment, and the like.

  For example, as a water-soluble organic solvent that can be expected to have a function of improving the permeability to the fabric and suppressing clogging of the nozzle, alkyl alcohols having 1 to 4 carbon atoms such as methanol, ethanol, butanol, propanol, and isopropanol, Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monomethyl ether acetate, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol mono-n-propyl ether, ethylene glycol mono-iso-propyl ether, diethylene glycol mono-iso-propyl ether , Ethylene glycol mono-n-butyl ether, diethylene glycol mono-n-butyl ether, triethylene glycol Coal mono-n-butyl ether, ethylene glycol mono-t-butyl ether, diethylene glycol mono-t-butyl ether, 1-methyl-1-methoxybutanol, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-t-butyl ether, Propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether , Propylene glycol mono-n-butyl ether, dipropylene glycol mono-n-butyl ether Glycol ethers, formamide, acetamide, dimethyl sulfoxide, sorbitol, sorbitan, acetin, diacetin, triacetin, sulfolane, and mixtures thereof.

  In the ink according to the present invention, the content of the water-soluble organic solvent is preferably 10 to 60% by mass.

(Fixing resin)
The pigment ink for inkjet textile printing of the present invention preferably further contains a fixing resin. The fixing resin that can be used in the present invention is not particularly limited, and either a water-dispersible fixing resin or a water-soluble fixing resin can be preferably used. In the present invention, after neutralizing with a base or the like to make it the most stable state with respect to water, 100 g or more soluble in 1 L of water is a water-soluble fixing resin, and those having a solubility of less than that are water dispersible. A fixing resin is used.

(Water dispersible fixing resin)
As the water-dispersible fixing resin that can be used in the present invention, for example, a styrene acrylic resin, a silicone resin, a polyester resin, a urethane resin, or a copolymer of two or more of them is preferable. When a water-dispersible fixing resin is used as the fixing resin, the water-dispersible fixing resin is relatively oil-soluble and can be fixed so as to cover the entire fixed pigment. Can be.

  In the present invention, it is preferable to use a water-dispersible fixing resin as the fixing resin. Although the reason is not clear, it is considered as follows.

  As described above, the water in the ink droplets is volatilized by heating and the amount of the water-soluble organic solvent is relatively increased, so that interface separation composed of a water layer and an oil layer occurs at a micro level inside the ink droplet. When interfacial separation occurs, a part of the water-dispersible fixing resin which is a water-dispersed emulsion (ie, O / W type) is drawn into the oil layer, and the oil layer-dispersed (ie, W / O type) resin. Or part of the resin is considered to dissolve in the oil layer. Since the water-dispersible fixing resin drawn into the oil layer is located at the upper part of the water layer, the resulting water layer containing the pigment is located at the lower part of the ink droplet, and the pigment is formed at the lower part of the resulting film. It will be fixed. That is, in the formed image, it is considered that the pigment in the image film is relatively located inside the film and the outcrop of the pigment is suppressed, so that the abrasion resistance and the fastness are further improved.

  As the styrene acrylic resin, one or more selected from a styrene- (meth) acrylic acid copolymer and a styrene- (meth) acrylic acid- (meth) acrylic acid ester copolymer can be used in combination. Examples of the (meth) acrylic acid ester include benzyl (meth) acrylate, cyclohexyl (meth) acrylate, methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, and hexyl (meth). Acrylate, octyl (meth) acrylate, lauryl (meth) acrylate, 2-ethylhexyl (meth) acrylate, 2-ethylhexyl carbitol (meth) acrylate, phenol EO modified (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl ( A (meth) acrylate, dicyclopentanyl (meth) acrylate, dicyclopentenyloxyethyl (meth) acrylate, etc. can be used.

  As the silicone resin, side chain type, one end type, both end types, side chain both end type modified silicone oil, and the like can be used.

  Examples of polyester resins include terephthalic acid, isophthalic acid, orthophthalic acid, 2,6-naphthalenedicarboxylic acid, sodium sulfoisophthalic acid, succinic acid, adipic acid, azelaic acid, sebacic acid, 1,10-decanedicarboxylic acid, dimer acid, etc. A trivalent or higher polyvalent carboxylic acid such as divalent carboxylic acid, trimellitic acid, and pyromellitic acid, ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1, 5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, diethylene glycol, triethylene glycol, polytetraethylene glycol, 1,4-cyclohexane Dimethanol, bisphee Polymers based on ester bonds of trihydric or higher polyhydric alcohols such as dihydric alcohols such as ethylene oxide adducts of triol A, trimethylolpropane, pentaerythritol, or their block copolymers, random copolymers, grafts Copolymers and the like can be used.

  Urethane resins include polypropylene glycol, polyethylene glycol, polytetramethylene glycol, poly (ethylene adipate), poly (diethylene adipate), poly (propylene adipate), poly (tetramethylene adipate), poly (hexamethylene adipate), poly- polyols such as ε-caprolactone, poly (hexamethylene carbonate), silicone polyol, and tolylene diisocyanate, 4,4-diphenylmethane diisocyanate, xylylene diisocyanate, naphthalene diisocyanate, hexamethylene diisocyanate, hydrogenated tolylene diisocyanate, hydrogenated 4 , 4-diphenylmethane diisocyanate, isophorone diisocyanate, tetramethylxylylene diisocyanate, etc. Polymer by urethane bonds isocyanate, or block copolymer thereof, random copolymers, and graft copolymers may be used.

  Further, not only the above resins but also copolymers between resins such as styrene acrylic resin-polyester resin copolymer, styrene acrylic resin-urethane resin copolymer, and the like are applicable.

  By setting the Tg of the water-dispersible fixing resin that can be used in the present invention in the range of −30 ° C. to 80 ° C., a printed matter having good abrasion resistance and flexibility can be obtained. A particularly preferred range is from 0 ° C to 50 ° C, most preferably from 20 ° C to 40 ° C.

  The acid value of the water-dispersible fixing resin that can be used in the present invention is preferably 44 mgKOH / g or more, and more preferably 60 mgKOH / g or more. The upper limit of the acid value is not particularly limited, but is preferably less than 110 mgKOH / g from the viewpoint of easily obtaining a more stable dispersion.

  The average particle size of the water-dispersible fixing resin that can be used in the present invention is preferably 300 nm or less, more preferably 130 nm, from the viewpoint of obtaining good gloss feeling without clogging in the nozzles of the ink jet recording head. It is as follows. The lower limit of the average particle diameter is preferably 30 nm from the viewpoint of production stability of fine particles.

(Water-soluble fixing resin)
The water-soluble fixing resin that can be used in the present invention is designed and used having a hydrophilic component that is a carboxyl group and a hydrophobic component in an appropriate balance. At this time, the water-soluble copolymer according to the present invention to which water solubility is imparted by neutralizing the carboxyl group with a volatile base component sufficiently exhibits the above-described function. Examples of such water-soluble copolymers include acrylic resins, styrene-acrylic resins, acrylonitrile-acrylic resins, vinyl acetate-acrylic resins, polyurethane resins, and polyester resins. When a water-soluble fixing resin is used as the fixing resin, the water-soluble fixing resin is preferably adjusted so that the dispersion stability is lost after the pigment dispersant loses the dispersion stability and precipitates. From this viewpoint, the water-soluble fixing resin is used. It is preferable to use a pKa smaller than that of the pigment dispersant described above. The water-soluble fixing resin is preferably neutralized with a mixed base composed of a volatile amine and an inorganic base.

  Examples of the hydrophobic monomer constituting the water-soluble fixing resin that can be used in the present invention include acrylate esters (for example, n-butyl acrylate, 2-ethylhexyl acrylate, 2-hydroxyethyl acrylate, etc.), methacryl Examples include acid esters (for example, ethyl methacrylate, butyl methacrylate, glycidyl methacrylate, etc.), styrene, and the like.

  Examples of the hydrophilic monomer constituting the water-soluble fixing resin that can be used in the present invention include acrylic acid, methacrylic acid, and acrylamide.

  The water-soluble fixing resin that can be used in the present invention contains 1.0% by mass or more and 10% by mass or less, more preferably 2.0% by mass or more and 7.0% by mass with respect to the total mass of the ink. It is below mass%. When the content of the water-soluble fixing resin that can be used in the present invention is 1.0% by mass or more, bleeding can be remarkably prevented and a high-quality image can be obtained. When the content is 10% by mass or less, the storage stability of the ink is remarkably good, stable emission is possible, and a print can be stably obtained over a long period of time.

  In addition, the water-soluble fixing resin that can be used in the present invention preferably has an acid value of 80 mgKOH / g or more and less than 300 mgKOH / g, which increases the viscosity of the water-soluble copolymer upon drying. Becomes noticeable and solidifies more firmly after drying, and the fixability of the pigment is good. A more preferred acid value is about 90 to 250 mg KOH / g. The acid value defined in the present invention can be measured according to JIS K0070.

  The polymerization method of the water-soluble fixing resin that can be used in the present invention is preferably solution polymerization. The molecular weight of the water-soluble fixing resin that can be used in the present invention is preferably an average molecular weight of 3000 to 30000, more preferably 7000 to 20000.

  The Tg of the water-soluble fixing resin that can be used in the present invention is preferably about -30 ° C to 100 ° C, more preferably -10 ° C to 50 ° C, and most preferably 20 ° C to 40 ° C. It is in the range of ° C.

  The pKa of the water-soluble fixing resin that can be used in the present invention can preferably be 4 to 8, more preferably 5 to 7. For the reasons described above, it is preferable to use a water-soluble fixing resin having a pKa smaller than that of the pigment dispersant.

(Other)
The pigment textile printing ink of the present invention may further contain a surfactant, an antiseptic agent, an antifungal agent and the like as necessary. Examples of surfactants include dialkyl sulfosuccinates, alkyl naphthalene sulfonates, polyoxyethylene alkyl ethers, polyoxyethylene alkyl allyl ethers, acetylene glycols, polyoxyethylene / polyoxypropylene block copolymers, alkyls Amine salts, quaternary ammonium salts, silicone surfactants, fluorine surfactants and the like are included. The content of the surfactant is preferably adjusted so that the surface tension of the ink is 25 to 60 mN / m. Specifically, it may be about 0.0001 to 5% by mass with respect to the whole ink.

  Examples of preservatives or antifungal agents include aromatic halogen compounds (eg, Preventol CMK), methylene dithiocyanate, halogen-containing nitrogen sulfur compounds, 1,2-benzisothiazolin-3-one (eg, PROXEL GXL), etc. Is included.

(Ink properties, etc.)
The viscosity at 25 ° C. of the pigment textile printing ink of the present invention is preferably 1 to 40 mPa · s, more preferably 5 to 40 mPa · s, and more preferably 5 to 20 mPa · s from the viewpoint of obtaining ink ejection stability. More preferably, it is s. The viscosity of the ink can be measured with an E-type viscometer at 25 ° C. and 1 rpm.

  The surface tension of the ink at 25 ° C. is preferably 25 to 60 mN / m. When the surface tension is less than 25 mN / m, the wettability of the ink with respect to a recording medium such as a fabric is too high, so that the image tends to bleed. On the other hand, when the surface tension is more than 60 mN / m, the wettability of the ink with respect to a recording medium such as a fabric is lowered, and the ink penetration force is likely to be lowered.

  The pigment textile printing ink of the present invention can be produced by an arbitrary method, for example, a process for obtaining a dispersion by dispersing a water-insoluble colorant with a dispersant and a process for preparing an ink using the dispersion. sell.

(Fabric)
The fabric printed using the ink and the coating liquid according to the present embodiment refers to “fabric”, “clothing and other clothing”, and the like.

  “Fabric” includes natural fibers such as cotton, silk, wool, etc., chemical fibers such as nylon, or woven fabrics, knitted fabrics, non-woven fabrics, etc., mixed with these, and is rolled up in a long form And those cut to a predetermined length.

  “Clothing and other apparel” includes post-sewing parts such as T-shirts, handkerchiefs, scarves, towels, handbags, cloth bags, curtains, sheets, bedspreads, etc. Also included are fabrics before and after cutting.

(Image forming method)
In the textile printing method of the present invention, an image is formed by ejecting ink onto a fabric supported by a support using a recording head. At that time, the volatile amine is volatilized by using drying means provided before and after the recording head, the stability of the pigment dispersant is lowered, and it is deposited on the fabric. Thereafter, a printed product can be produced through a heat fixing step.

  The textile printing method of the present invention is performed by ink jet recording in which ink droplets are ejected by an ink jet recording head portion. The ink jet recording head may be an on-demand type or a continuous type. In addition, the inkjet recording head discharge method is an electro-mechanical conversion method (for example, a single cavity type, a double cavity type, a bender type, a piston type, a shear mode type, a shared wall type, etc.), an electro-thermal conversion method ( For example, any discharge method such as a thermal ink jet type or a bubble jet (registered trademark) type may be used.

  In the textile printing method of the present invention, the printing method is not particularly limited, and may be either a single pass type or a scan type, but a single pass type is preferable because it is effective for high-speed printing. The single-pass ink jet recording method is an ink jet recording method in which when a recording medium passes under one ink jet head unit, all dots for forming pixels are ejected in one pass.

  As means for achieving the single-pass type image forming method, it is preferable to use a line head type ink jet head.

  The line head type ink jet head refers to an ink jet head having a length equal to or greater than the width of the printing range. As a line head type inkjet head, one head may be larger than the width of the printing range, or a combination of a plurality of heads as disclosed in JP 2007-320278 may exceed the width of the printing range. It may be configured.

  The ink that has landed on the fabric is preferably removed from the volatile amine and water in the ink by a drying means. The ink drying means is not particularly limited. For example, a heating method, an air blowing method, or a method for removing volatile components by a decompression process can be appropriately selected or combined, but the equipment is simple. Therefore, it is preferable to use a drying method by heating or a drying method by blowing air.

  As a drying method by heating the ink, any method such as a heater, a warm air dryer or a heating roller can be preferably used, but it is preferable to dry by heating with a heater, a warm air dryer or a heating roller. When the ink is dried using the heating means, a heating means such as a heater may be disposed behind the ink jet recording head section, and the ink may be dried by heating both the fabric and the landed ink. The ink that is disposed in front of the head portion and landed by the thermal energy stored in the fabric before ink jet recording may be dried, or may be disposed both before and after the ink jet recording head portion. Moreover, it is preferable to dry by heating both surfaces of a fabric using a warm air dryer and a heater as a preferable drying form.

  It is preferable to heat the surface of the fabric on which the image is formed because the ink according to the present invention can be further dried at the same time. As this heating method, heating may be performed from the back side of the surface on which image formation is performed. There is no restriction | limiting in particular in the kind of heater, It is preferable to select and apply suitably from well-known methods, such as an infrared heater, a heating wire, a UV lamp, gas, and a hot air dryer. Among these, heating with a heating wire or an infrared heater is preferable from the viewpoint of safety and energy efficiency.

  In order to further improve the drying speed and sharpness of the discharged ink, the surface temperature of the surface to which the inkjet ink is applied is heated to 40 ° C. or higher and 60 ° C. or lower. The image forming apparatus applied to the image forming method of the present invention preferably includes a heater for heating the fabric.

  In addition, when inkjet printing is performed on the fabric using the inkjet printing ink of the present invention, a dye fixing process is performed after characters and / or images are printed on the fabric. Examples of the dye fixing treatment include heat treatment by a method similar to that in the conventional textile printing method, for example, a normal pressure steam method, a high pressure steam method, a thermofix method, and the like. The temperature during the heat treatment is preferably 120 to 200 ° C, more preferably 140 to 180 ° C. After the heat treatment, the fabric may be washed with water and dried as necessary.

(Pretreatment agent)
In the image forming method according to the present invention, printing is performed on a fabric pretreated with a pretreatment agent containing water, a polyvalent metal ion or a polymer as necessary for reasons such as preventing ink bleeding and improving fixability. You may go.

  When the pretreatment is performed with the pretreatment agent, image formation is performed on the fabric that has been pretreated with the pretreatment agent, so-called inline in which the pretreatment is performed continuously with the printing by the ink jet apparatus even in the so-called off-line treatment. It may be a process. When the pretreatment is performed by inline processing, the pretreatment device may be integrated with the ink jet device or may be a separate body.

  Moreover, there is no restriction | limiting in particular about the application | coating method of a pretreatment agent, You may apply | coat by an inkjet system similarly to ink, and may apply | coat using a coater etc. In particular, when the pretreatment agent contains a component that remains in the fabric even after the washing step after heat fixing, such as a fixing resin, the pretreatment agent may be applied by an ink jet method and applied to only a necessary portion. Good.

  Hereinafter, the present invention will be described more specifically with reference to examples and the like. In addition, this invention is not limited to this Example at all. In addition, “parts” and “%” in the compositions of the following examples are “parts by mass” and “% by mass”, respectively.

(Preparation of pigment dispersion)
(1) Production of Pigment Dispersion C1 for Cyan Ink 10% Ammonia Water and 5% Aqueous Sodium Hydroxide Mole of Ammonia and Sodium Hydroxide for 3 parts by mass of Jonkrill 678 (manufactured by BASF) as a pigment dispersant The mixed base mixed so that the ratio was 4: 1 was added so that the molar amount was 1.1 times the neutralization equivalent of Joncrill 678. This was mixed with 80.7 parts by mass of water and then heated and stirred to prepare a neutralized product of the pigment dispersant. C.I. I. After adding 15 parts by weight of Pigment Blue 15: 3 and premixing, the mixture was dispersed using a sand grinder filled with 50% by volume of 0.5 mm zirconia beads to obtain a cyan pigment dispersion C1 having a pigment solid content of 15%. Got.

(2) Production of white ink pigment dispersion W1 The pigment dispersion W1 is C.I. I. Pigment White 6 (Rutyl Titanium Oxide Pigment ST410WB: manufactured by Titanium Industry Co., Ltd.), the dispersant was adjusted to 12% of the mass of the pigment, and the addition amount of the mixed base was 1.1 equivalent to the neutralization equivalent of the pigment dispersant. A pigment dispersion W1 was prepared in the same manner as the pigment dispersion C1, except that the molar amount was doubled.

(3) Production of Pigment Dispersions C2 to C7 and W2 to W7 Pigment Dispersions C2 to C7 and W2 to W7 were used to prepare pigment dispersions C1 and W1, respectively. The pigment dispersions C2 to C7 and W2 were prepared in the same manner except that the mixing molar ratio of the neutralizing base was changed as shown in Table 1 while the molar amount was fixed to 1.1 times the equivalent amount. -W7 was produced.

(4) Manufacture of pigment dispersions C8 to C14 and W8 to W14 The pigment dispersions C8 to C14 and W8 to W14 are described in Table 2 below in the preparation of pigment dispersions C1 and W1, respectively. The pigment dispersions C8 to C14 and W8 to W14 were prepared in the same manner except that the pigment dispersant was changed to the above pigment dispersant.

(Fixing resin)
A water-soluble fixing resin and a water-dispersible fixing resin were prepared in the following manner.

(Synthesis of water-soluble fixing resin SP-1)
50 parts of methyl ethyl ketone was added to a flask equipped with a dropping funnel, a nitrogen introducer, a reflux condenser, a thermometer and a stirring device, and heated to 75 ° C. while bubbling nitrogen. To this, a monomer (9 parts of methacrylic acid, 8 parts of n-butyl acrylate, 5 parts of 2-ethylhexyl acrylate and 78 parts of n-butyl methacrylate), 50 parts of methyl ethyl ketone, an initiator (AIBN: 2,2 ′ -Azobisisobutyronitrile) and a mixture of 0.5 parts were dropped from a dropping funnel over 3 hours. After the dropwise addition, the mixture was further heated under reflux for 6 hours. The resulting solution was allowed to cool and then heated under reduced pressure to distill off methyl ethyl ketone to obtain a copolymer.

  On the other hand, with respect to 450 parts of ion-exchange water, it neutralized with the base so that it might become 1.1 times molar equivalent of methacrylic acid which is the unneutralized carboxylic acid added as a monomer. The copolymer was dissolved in this solution and further adjusted with ion exchange water to obtain a solution (resin solution) of water-soluble fixing resin SP-1 having a solid content concentration of 20% by mass. For neutralization of the water-soluble fixing resin SP-1, the same mixed base used for neutralizing the pigment dispersion at the time of preparing the cyan ink or white ink described below was used. That is, when used when preparing the cyan ink 2-1, a mixed base of sodium hydroxide: ammonia = 1: 4 (molar ratio) is used. When using the mixed base when preparing the white ink 2-3, sodium hydroxide: ammonia = 1: 2. A water-soluble fixing resin SP-1 neutralized with a mixed base (molar ratio) was used.

(Synthesis of water-soluble fixing resins SP-2 to SP-6)
Water-soluble fixing resins SP-2 to SP-6 were synthesized in the same manner except that the monomer composition was changed as shown in Table 3 in the synthesis of the water-soluble fixing resin SP-1. Further, the weight average molecular weight of the fixing resin was appropriately adjusted depending on the initiator amount and the polymerization conditions.

  The acid value, glass transition temperature (Tg) and weight average molecular weight of the obtained fixing resin were measured according to the following methods.

(Measurement of acid value)
The acid value was measured by the method defined in JIS K0070. That is, the resin solution was dried and solidified to obtain a resin. 10 g of the obtained resin was weighed into a 300 ml Erlenmeyer flask, and about 50 ml of a mixed solvent of ethanol: benzene = 1: 2 was added to dissolve the resin. Subsequently, this solution was titrated with a 0.1 mol / L potassium hydroxide ethanol solution standardized in advance using a phenolphthalein indicator. And the acid value (mgKOH / g) was calculated | required by the following formula (1) from the quantity of the potassium hydroxide ethanol solution used for titration.

Formula (1)
A = (B × f × 5.611) / S
(Wherein, A is the acid value of the fixing resin (mgKOH / g), B is the amount of 0.1 mol / L potassium hydroxide ethanol solution used for titration (ml), and f is 0.1 mol / liter potassium hydroxide ethanol. The factor of the solution, S is the mass (g) of the fixing resin, 5.611 is 1/10 of the formula weight of potassium hydroxide (56.11 / 10))

(Water dispersible fixing resin)
As the water dispersible fixing resins DP-1 to DP-6, commercially available water dispersible fixing resins were used.
Water dispersible fixing resin DP-1: Jonkrill 734 (glass transition temperature: 30 ° C., manufactured by Johnson Polymer Co., Ltd.)
Water dispersible fixing resin DP-2: AE series AE343 (glass transition temperature: 0 ° C., manufactured by JSR Corporation)
Water dispersible fixing resin DP-3: Movinyl 742N (glass transition temperature: 37 ° C., manufactured by Clariant Polymer Co., Ltd.)
Water dispersible fixing resin DP-4: AE series AE140 (glass transition temperature: 53 ° C., manufactured by JSR Corporation)
Water dispersible fixing resin DP-5: Mobile 937 (Glass transition temperature: -42 ° C., manufactured by Clariant Polymer Co., Ltd.)
Water dispersible fixing resin DP-6: AE series AE379A (glass transition temperature: 20 ° C., manufactured by JSR Corporation)

(Preparation of ink)
Cyan ink 1-1 having a water-dispersible fixing resin as a fixing resin, white ink 1-1, cyan ink 2-1 having a water-soluble fixing resin as a fixing resin, and white ink 2-1 were prepared according to the following formulation.

(Cyan ink 1-1)
Dispersion C1 (15% pigment solid content) 24.0%
Water dispersible fixing resin DP-1 (solid content 40%) 12.5%
Triethylene glycol monobutyl ether 2.0%
1,2-hexanediol 1.0%
Trimethylolpropane 4.0%
Glycerin 12.0%
Triethylene glycol 2.0%
Surfynol 104 (acetylene glycol surfactant made by Nissin Chemical) 0.1%
Olfine E1010 (Nisshin Chemical's acetylene glycol surfactant) 0.8%
Proxel XLII (Arch Chemicals Japan) 0.3%
1,2-hexanediol 0.5%
Ion exchange water

(White ink 1-1)
Dispersion W1 (pigment solid content 15%) 50.0%
Water dispersible fixing resin DP-1 (solid content 40%) 12.5%
Triethylene glycol monobutyl ether 2.0%
1,2-hexanediol 1.0%
Trimethylolpropane 1.5%
Glycerin 8.0%
Triethylene glycol 1.0%
Surfynol 104 (acetylene glycol surfactant made by Nissin Chemical) 0.1%
Olfine E1010 (Nisshin Chemical's acetylene glycol surfactant) 0.8%
Proxel XLII (Arch Chemicals Japan) 0.3%
1,2-hexanediol 0.5%
Water remaining

(Cyan ink 2-1)
Dispersion C1 (15% pigment solid content) 24.0%
Water-soluble fixing resin SP-1 (solid content 40%) 12.5%
Triethylene glycol monobutyl ether 2.0%
1,2-hexanediol 1.0%
Trimethylolpropane 4.0%
Glycerin 12.0%
Triethylene glycol 2.0%
Surfynol 104 (acetylene glycol surfactant made by Nissin Chemical) 0.1%
Olfine E1010 (Nisshin Chemical's acetylene glycol surfactant) 0.8%
Proxel XLII (Arch Chemicals Japan) 0.3%
1,2-hexanediol 0.5%
Ion exchange water

(White ink 2-1)
Dispersion W1 (pigment solid content 15%) 50.0%
Water-soluble fixing resin SP-1 (solid content 40%) 12.5%
Triethylene glycol monobutyl ether 2.0%
1,2-hexanediol 1.0%
Trimethylolpropane 1.5%
Glycerin 8.0%
Triethylene glycol 1.0%
Surfynol 104 (acetylene glycol surfactant made by Nissin Chemical) 0.1%
Olfine E1010 (Nisshin Chemical's acetylene glycol surfactant) 0.8%
Proxel XLII (Arch Chemicals Japan) 0.3%
1,2-hexanediol 0.5%
Water remaining

Preparation of cyan ink 1-2 to cyan ink 1-7, white ink 1-2 to white ink 1-7, cyan ink 2-2 to cyan ink 2-7, white ink 2-2 to white ink 2-7 In the preparation of cyan ink 1-2, white ink 1-2, cyan ink 2-2, and white ink 2-2, the ratio of the neutralized salt of the pigment dispersion and the water-soluble fixing resin is as shown in Table 4 below. Each ink was prepared in the same manner except that.

Production of cyan ink 1-8 to cyan ink 1-14, white ink 1-8 to white ink 1-14, cyan ink 2-8 to cyan ink 2-14, and white ink 2-8 to white ink 2-14 In the preparation of cyan ink 1-2, white ink 1-2, cyan ink 2-2, and white ink 2-2, the ratio of the neutralized salt of the pigment dispersion and the water-soluble fixing resin is as shown in Table 5 below. Each ink was prepared in the same manner except that.

Preparation of Cyan Ink 1-15 to Cyan Ink 1-19, White Ink 1-15 to White Ink 1-19, Cyan Ink 2-15 to Cyan Ink 2-19, White Ink 2-15 to White Ink 2-19 In the production of cyan ink 1-2, white ink 1-2, cyan ink 2-2, and white ink 2-2, each ink was produced in the same manner except that the fixing resin was as shown in Table 6 below. did.

(Method for producing printed matter)
Using the ink manufactured by the above method and using a Konica Minolta Co., Ltd. Nassenger V partially remodeled as an inkjet printer, the temperature of the platen part can be adjusted, and the surface temperature of the fabric in the printing part is 50 ° C. The printed matter was printed with a solid print on a cotton cloth. In solid printing, a white cotton cloth was used as a cyan ink test sample, and an image was formed on a cotton cloth dyed with a black dye as a white ink test sample.

  Thereafter, heat treatment was performed at 150 ° C. for 5 minutes to obtain a sample printed matter.

  Further, in the examples, some printed products use pretreated fabric, and a pretreated agent composed of an aqueous solution of carboxymethylcellulose and magnesium chloride is applied to the entire cotton fabric using a mangle device and dried. It was.

(Abrasion resistance test and dry cleaning test)
The sample (printed material) was subjected to friction fastness by rubbing 200 times at a load of 300 g using a Gakushin friction fastness tester AB-301S manufactured by Tester Sangyo Co., Ltd. Evaluation was made at a dry level according to Japanese Industrial Standard (JIS) JIS L0849 for confirming the degree of ink peeling. Similarly, the dry cleaning test was evaluated by the method B of JIS L0860. The results of the abrasion resistance test and the dry cleaning test are shown in Tables 7 to 10.

  In the evaluation, Grade 5 was rated as ◎, Grade 4 as ◯, Grades 3 and 2 as △, and lower grades as ×.

(Measurement of color development)
Using a printed sample, GRETAG SPECTROSCAN SPM-50 was used to evaluate the saturation of cyan and whiteness of white as indexes of color development.
Saturation is 43 or more, ◎, 42 to 41 is ◯, 40 to 38 is Δ, and less than that is ×.
The whiteness was evaluated as ◎ for 80 or more, ◯ for 79 to 75, Δ for 74 to 70, and × for less than that.

(Measurement of discharge stability)
A part of Konica Minolta Co., Ltd.'s Nassenger V was remodeled as an ink jet printer, and the temperature of the platen part could be adjusted, using cotton cloth at 35 ° C and 35% atmosphere. Printed and evaluated. The case where there was no printing disturbance at all, the case where there was a printing disorder at one place, the case where there was a printing disorder at 2 to 3 places, and the case where there was printing disorder at 4 or more places as x.

  The evaluation results are shown in Tables 7 to 10 below.

  In the above results, although the ink set 34, the ink set 35, and the ink set 40 gave good results, the texture was somewhat poor because a resin having a high glass transition temperature was used.

(Manufacture of ink sets)
In the production of the pigment dispersion C1 for cyan ink, the pigment is C.I. I. Pigment Black 7 (carbon black: manufactured by Mitsubishi Chemical), C.I. I. Pigment Red 122 (quinacridone pigment: Clariant) and C.I. I. A pigment dispersion for black ink, a pigment dispersion for magenta ink, and a pigment dispersion for yellow ink were produced in the same manner except that the pigment yellow 180 (benzimidazolone pigment: manufactured by Clariant) was used.

  Further, in the production of the cyan ink 1-1, the black ink and the magenta were changed in the same manner except that the pigment dispersion was changed to the black ink pigment dispersion, the magenta ink pigment dispersion, and the yellow ink pigment dispersion, respectively. Ink and yellow ink were produced, and a cyan ink 1-1 and white ink 1-1 were combined to produce a six-color printing ink set.

  When the formed textile printing ink set was subjected to image formation using Nassenger V manufactured by Konica Minolta Co., Ltd., a printed matter having excellent abrasion resistance, dry cleaning resistance, and color development property could be obtained.

Claims (7)

A pigment printing ink comprising a pigment, water, and a water-soluble organic solvent, wherein the pigment is dispersed by a pigment dispersant, and the pigment dispersant is neutralized by a volatile amine and an inorganic base. Pigment printing ink. The pigment printing ink according to claim 1, wherein the pigment dispersant is neutralized with a mixed base of volatile amine and inorganic base in the range of 9: 1 to 1: 4. The pigment printing ink according to claim 1 or 2, wherein the pigment printing ink further contains a fixing resin. The pigment printing ink according to claim 3, wherein the fixing resin is a water-dispersible fixing resin, and the glass transition temperature of the water-dispersible fixing resin is -30 ° C to 80 ° C. The pigment printing ink according to any one of claims 1 to 4, wherein the volatile amine is ammonia. An ink-jet printing method comprising forming an image by an ink-jet method using the pigment printing ink according to any one of claims 1 to 5. The ink-jet printing method according to claim 6, further comprising a step of heating the fabric during image formation or before and after image formation.