JP7395909B2 - Ink and printed matter manufacturing method - Google Patents

Description

The present invention relates to an ink that can be used in a printing device equipped with an ink circulation type inkjet head.

In recent years, as an inkjet printing device, a printing device equipped with an ink circulation type inkjet head is known to prevent clogging of ejection nozzles caused by sedimentation of pigments, resin particles, etc. within the inkjet head ( For example, see Patent Document 1.)

The ink circulation type inkjet head has, for example, an ink inflow path and an ink outflow path in addition to an ink discharge nozzle, and the ink that flows out from the outflow path passes through the inflow path and returns to the inkjet head. Some inks are known to have an ink circulation structure in which the ink is supplied to the ink, and some are equipped with a filter to capture pigments and the like that settle during the circulation process.

On the other hand, as the ink is required to have good abrasion resistance and water resistance in printed matter, the development of an ink containing a binder resin is being considered. In particular, inks used for printing on fabric products such as clothing contain more binder resin than inks used for printing on plain paper, in order to form printed images with good washing fastness. may be used.

However, when an ink containing a large amount of binder resin is applied to a printing device equipped with the ink circulation type inkjet head, a film is formed over time on the surface of the filter during the circulation process, causing clogging of the filter. may cause.

As a method for preventing clogging of the filter, there is a method of using ink containing a small amount of the binder resin or the like.

However, when using ink with a reduced content of binder resin, etc., it may cause a decrease in the abrasion resistance and water resistance of printed matter, and when the ink is applied to fabric products, it may cause a significant decrease in washing fastness. It could cause it.

JP2018-043511A

The problem to be solved by the present invention is that even when applied to a printing device equipped with an ink circulation type inkjet head, it is difficult to cause clogging of a filter provided in the middle of an ink circulation path over time, and An object of the present invention is to provide an ink that can be used for producing printed matter with excellent washing fastness.

The present invention provides an ink for use in a printing device equipped with an ink circulation type inkjet head, the ink comprising a polyurethane (A) having a carbonate structure, a polyurethane (B) having an ether structure, and a solvent (C). The present invention relates to an ink characterized by containing:

Even when the ink of the present invention is applied to a printing device equipped with an ink circulation type inkjet head, it is difficult to cause clogging of the filter provided in the middle of the ink circulation path over time, and it is easy to wash. It can be used to produce printed matter with excellent durability.

FIG. 1 is a schematic diagram of a microreactor used in the present invention.

The ink of the present invention contains a polyurethane (A) having a carbonate structure, a polyurethane (B) having an ether structure, and a solvent (C) among inks used in a printing device equipped with an ink circulation type inkjet head. It is characterized by:

The ink of the present invention does not simply contain polyurethane, but rather contains a combination of the polyurethane (A) and polyurethane (B). By using the polyurethane (A) and polyurethane (B) in combination, even when applied to a printing device equipped with an ink circulation type inkjet head, the filter installed in the middle of the ink circulation path can be It is possible to produce printed matter that is less likely to cause clogging and has excellent washing fastness.

As the ink of the present invention, one in which the mass ratio of the polyurethane (A) and the polyurethane (B) [the polyurethane (A)/the polyurethane (B)] is in the range of 1.5 to 9 is used. is preferable, it is more preferable to use a value in the range of 1.5 to 7, and it is more preferable to use a value in the range of 1.5 to 5. This is particularly preferred for producing printed matter that is less likely to cause clogging and has excellent washing fastness.

The ink of the present invention preferably contains the polyurethane (A) and the polyurethane (B) in a total amount of 5% by mass to 15% by mass, based on the total amount of the ink of the present invention. Using a substance containing a content in the range of 10% by mass makes it more difficult to clog the filter provided in the ink circulation path over time, and produces printed matter with excellent washing fastness. More preferable for manufacturing.

First, polyurethane (A) used in the ink of the present invention will be explained.

The polyurethane (A) is a polyurethane (A) having a carbonate structure, and is an essential component for producing printed matter with excellent washing fastness.

As the polyurethane (A), it is preferable to use one having a carbonate structure in the range of 10% by mass to 90% by mass, based on the total mass of the polyurethane (A), and preferably in the range of 50% by mass to 90% by mass. It is more preferable to use the same in order to obtain printed matter with excellent washing fastness.

The polyurethane (A) preferably has a weight average molecular weight of 10,000 to 200,000. In particular, as the polyurethane (A), a polyurethane having a weight average molecular weight of 10,000 to 50,000 that does not have a urea bond, or a polyurethane having a weight average molecular weight of 70,000 to 170,000 that has a urea bond may be used alone or in combination. This is more preferable in producing printed matter that is less likely to cause clogging of a filter provided in the middle of the ink circulation path over time and has excellent washing fastness.

The polyurethane (A) is preferably used in a range of 3% by mass to 13.5% by mass based on the total amount of the ink of the present invention, and is preferably used in a range of 3% by mass to 9% by mass. More preferable for producing printed matter with excellent fastness.

As the polyurethane (A), it is preferable to use a polyurethane having a hydrophilic group in order to improve the water dispersion stability in the ink of the present invention.

As the hydrophilic group, what is generally called an anionic group, a cationic group, or a nonionic group can be used. Among these, it is preferable to use an anionic group or a cationic group as the hydrophilic group.

As the anionic group, for example, a carboxyl group, a carboxylate group, a sulfonic acid group, a sulfonate group, etc. can be used, and among them, a carboxylate group partially or completely neutralized with a basic compound, etc. The use of sulfonate groups is preferred in order to maintain good water dispersion stability.

Examples of basic compounds that can be used to neutralize the carboxyl group or sulfonic acid group as the anionic group include organic amines such as ammonia, triethylamine, pyridine, and morpholine, alkanolamines such as monoethanolamine, Na, Examples include metal base compounds containing K, Li, Ca, and the like. Among these, the basic compound may be used to prevent problems in washing fastness of the printed image due to remaining in the printed image (i.e., dry film) formed with the ink of the present invention. It is preferable to use an organic amine, and it is more preferable to use an organic amine having a boiling point of 100° C. or lower, such as ammonia or triethylamine.

Further, as the cationic group, for example, a tertiary amino group or the like can be used. As the acidic compound that can be used to neutralize some or all of the tertiary amino groups, for example, formic acid, acetic acid, etc. can be used. Further, as a quaternizing agent that can be used when quaternizing some or all of the tertiary amino groups, for example, dialkyl sulfates such as dimethyl sulfate and diethyl sulfate can be used.

In addition, examples of the nonionic group include polyoxyalkylene groups such as a polyoxyethylene group, a polyoxypropylene group, a polyoxybutylene group, a poly(oxyethylene-oxypropylene) group, and a polyoxyethylene-polyoxypropylene group. can be used. Among these, it is preferable to use a polyoxyalkylene group having an oxyethylene unit as the nonionic group in order to further improve hydrophilicity.

As the polyurethane (A), it is preferable to use a polyurethane having 0.5% to 30% by mass of the hydrophilic group, and preferably 1% to 20% by mass, based on the total amount of the polyurethane (A). In order to obtain an ink with even better aqueous dispersion stability, it is more preferable to use the same.

More specifically, as the polyurethane (A), a reaction product of a polyol including a polycarbonate polyol and a polyisocyanate can be used. Moreover, as the polyurethane (A), a reaction product of polyol and polyisocyanate including a polycarbonate polyol and a polyol having a hydrophilic group can be used. Furthermore, when a polyurethane having a urea bond is used as the polyurethane (A), a reaction product of a polyol including a polycarbonate polyol and a polyisocyanate and a chain extender such as a polyamine can be used.

As the polycarbonate polyol, for example, a reaction product of a carbonate ester and a low molecular weight polyol, preferably a linear aliphatic diol, can be used.

As the carbonate ester, methyl carbonate, dimethyl carbonate, ethyl carbonate, diethyl carbonate, cyclocarbonate, diphenyl carbonate, etc. can be used.

Examples of low molecular weight polyols that can react with the carbonate ester include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, dipropylene glycol, 1,4-butanediol, 1 , 3-butanediol, 1,2-butanediol, 2,3-butanediol, 1,5-pentanediol, 1,5-hexanediol, 2,5-hexanediol, 1,6-hexanediol, 1, 7-heptanediol, 1,8-octanediol, 1,9-nonanediol, 1,10-decanediol, 1,11-undecanediol, 1,12-dodecanediol, 1,4-cyclohexanediol, 1,4 - Relatively low molecular weight dihydroxy compounds such as cyclohexanedimethanol, hydroquinone, resorcinol, bisphenol-A, bisphenol-F, and 4,4'-biphenol, and polyether polyols such as polyethylene glycol, polypropylene glycol, and polyoxytetramethylene glycol. and polyester polyols such as polyhexamethylene adipate, polyhexamethylene succinate, and polycaprolactone.

As the polyol having a hydrophilic group that can be used to produce the polyurethane having a hydrophilic group, for example, a polyol having a cationic group such as a polyol having a tertiary amino group can be used. As the polyol having a tertiary amino group, specifically, N-methyl-diethanolamine, a polyol obtained by reacting a compound having two epoxy groups with a secondary amine, etc. can be used.

As the polyol having a hydrophilic group, one having an anionic group can be used , such as 1,2-bis(hydroxymethyl)propionic acid and 1,2-bis(hydroxymethyl)butanoic acid. can do.

As the polyol having a hydrophilic group, one having a nonionic group can be used, such as polyethylene glycol or polypropylene glycol having a structural unit derived from ethylene oxide.

As polyols that can be used in the production of the polyurethane (A), in addition to the polycarbonate polyols and polyols having a hydrophilic group, other polyols can be used as necessary.

As the other polyols, for example, polyether polyols, polyester polyols, etc. can be used.

Examples of the polyether polyol include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, trimethylene glycol, 1,3-butanediol, 1,4-butanediol, 1,6-hexanediol, neopentyl glycol, Glycerin, trimethylolethane, trimethylolpropane, sorbitol, sucrose, aconite sugar, femimellitic acid, phosphoric acid, ethylenediamine, diethylenetriamine, triisopropanolamine, pyrogallol, dihydroxybenzoic acid, hydroxyphthalic acid, 1,2,3-propane Addition polymerization of a cyclic ether compound such as ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin, tetrahydrofuran, cyclophexylene, etc. to a compound having two or more active hydrogen groups such as trithiol, or the above-mentioned cyclic ether compound Ring-opening polymerization using a cationic catalyst, a protonic acid, a Lewis acid, etc. as a catalyst can be used.

In addition, the polyester polyols include a reaction product of a diol and a dicarboxylic acid, a product obtained by a dehydration condensation reaction of a hydroxycarboxylic acid alone or in combination with a diol or a dicarboxylic acid, and a ring-opening polymerization of a cyclic ester compound such as ε-caprolactone. Reactants etc. can be used.

Examples of the diol include ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, and 1,6-hexane. Diol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, polypropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, Examples include bisphenol A, hydrogenated bisphenol A, hydroquinone, and alkylene oxide adducts thereof.

Examples of the dicarboxylic acids include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, maleic acid, fumaric acid, 1,3-cyclopentanedicarboxylic acid, 1,4-cyclohexanedicarboxylic acid, terephthalic acid, Isophthalic acid, phthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, naphthalic acid, biphenyldicarboxylic acid, 1,2-bis(phenoxy)ethane-p,p '-dicarboxylic acids and the like.

Examples of the hydroxycarboxylic acid include p-hydroxybenzoic acid and p-(2-hydroxyethoxy)benzoic acid.

In addition to the above-mentioned other polyols, ethylene glycol, propylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, Diol, 1,6-hexanediol, neopentyl glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, polyethylene glycol, dipropylene glycol, tripropylene glycol, bishydroxyethoxybenzene, 1,4-cyclohexanediol, 1,4- Relatively low molecular weight polyols such as cyclohexanedimethanol, bisphenol A, hydrogenated bisphenol A, hydroquinone and their alkylene oxide adducts, glycerin, trimethylolethane, trimethylolpropane, sorbitol, pentaerythritol, etc., alone or in combination. The above can be used in combination.

Examples of the polyisocyanate that reacts with the polyol include aromatic diisocyanates such as phenylene diisocyanate, tolylene diisocyanate, diphenylmethane diisocyanate, and naphthalene diisocyanate, hexamethylene diisocyanate, lysine diisocyanate, cyclohexane diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate, and xylylene diisocyanate. Isocyanates, aliphatic or aliphatic cyclic structure-containing diisocyanates such as tetramethylxylylene diisocyanate, etc. can be used alone or in combination of two or more.

In particular, when the ink of the present invention is used for printing on fabrics such as clothes, the polyisocyanate may be aliphatic or aliphatic such as isophorone diisocyanate or dicyclohexylmethane diisocyanate, in order to further improve the texture of printed matter. Preference is given to using diisocyanates containing cyclic structures.

Further, in the ink of the present invention, a crosslinking agent described below can be used for the purpose of further improving abrasion resistance such as washing fastness. When using the crosslinking agent, it is preferable to use a urethane resin having a functional group capable of crosslinking with the functional group of the crosslinking agent.

However, since it is undeniable that ink containing a crosslinking agent may crosslink within the circulation path of the ink circulation type inkjet head, it is necessary to prevent the filter provided in the circulation path from clogging, etc. Preferably, the ink does not contain.

Further, when using a polyurethane having a urea bond as the polyurethane (A), it is preferable to use a reaction product of a polyol such as the polycarbonate polyol, a polyisocyanate, and a polyamine as a chain extender.

Inks containing polyurethane with urea bonds are generally suitable for producing printed matter with excellent washing fastness, but there is concern that they may clog filters in ink circulation type inkjet heads over time. may be done.

However, if the ink of the present invention contains a combination of polyurethane (A) having a carbonate structure and polyurethane (B) having an ether structure, the polyurethane having a urea bond may be used as the polyurethane (A). This has the advantageous effect that it is possible to produce printed matter that is less likely to cause clogging and has excellent washing fastness.

Examples of the polyamine include ethylenediamine, 1,2-propanediamine, 1,6-hexamethylenediamine, piperazine, 2,5-dimethylpiperazine, isophoronediamine, 4,4'-dicyclohexylmethanediamine, 3,3'- Diamines such as dimethyl-4,4'-dicyclohexylmethanediamine, 1,4-cyclohexanediamine; N-hydroxymethylaminoethylamine, N-hydroxyethylaminoethylamine, N-hydroxypropylaminopropylamine, N-ethylaminoethylamine, N-methylaminopropylamine; diethylenetriamine, dipropylenetriamine, triethylenetetramine; hydrazine, N,N'-dimethylhydrazine, 1,6-hexamethylenebishydrazine; succinic acid dihydrazide, adipic acid dihydrazide, glutaric acid dihydrazide, sebacic acid Dihydrazide, isophthalic acid dihydrazide; β-semicarbazide propionic acid hydrazide, 3-semicarbazide-propyl-carbazate, semicarbazide-3-semicarbazidomethyl-3,5,5-trimethylcyclohexane can be used, hydrazine It is preferable to use the above ink in order to obtain an ink that is less likely to cause clogging and can produce printed matter with excellent washing fastness.

The polyamine has an equivalent of amino groups of 0.01 to 1.0 (equivalent ratio) relative to the equivalent of isocyanate groups of the urethane prepolymer, which is a reaction product of the polyol and polyisocyanate. It is preferable to use it in the range of 0.01 to 0.5 (equivalent ratio), more preferably 0.01 to 0.3 (equivalent ratio).

In addition to the polyamine, examples of the chain extender include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, and hexane glycol. Glycols such as methylene glycol, neopentyl glycol, saccharose, methylene glycol, glycerin, sorbitol; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4,4'-dihydroxydiphenyl sulfone, hydrogenation Phenols such as bisphenol A and hydroquinone, water, etc. can also be used.

The chain extender can be used when the polyol and polyisocyanate are reacted or after the reaction.

Next, the polyurethane (B) will be explained.

The polyurethane (B) has an ether structure and is an essential component for suppressing clogging of a filter provided in the ink circulation path over time.

As the polyurethane (B), it is preferable to use one having an ether structure in a range of 10% by mass to 90% by mass based on the entire mass of the polyurethane (B), and in a range of 50% by mass to 90% by mass. It is more preferable to use such a filter in order to further prevent clogging of a filter provided in the ink circulation path over time.

The polyurethane (B) preferably has a weight average molecular weight of 10,000 to 50,000, and preferably has a weight average molecular weight of 30,000 to 50,000. This is more preferable in terms of suppressing clogging over time.

The polyurethane (B) is preferably used in a range of 0.5% by mass to 6% by mass, and preferably in a range of 0.5% by mass to 4% by mass, based on the total amount of the ink of the present invention. , is more preferable in terms of suppressing clogging of a filter provided in the middle of the ink circulation path over time.

As the polyurethane (B), it is preferable to use a polyurethane having a hydrophilic group in order to improve the water dispersion stability in the ink of the present invention.

As the hydrophilic group, the same hydrophilic groups as those exemplified as those that can be added to the polyurethane (A) can be used.

More specifically, as the polyurethane (B), a reaction product of a polyol including a polyether polyol and a polyisocyanate can be used. Moreover, as the polyurethane (B), a reaction product of a polyol and a polyisocyanate containing a polyether polyol and a polyol having a hydrophilic group can be used.

As the polyether polyol, the same polyether polyols as those exemplified as polyols usable for producing the polyurethane (A) can be used. As the polyether polyol, it is preferable to use trimethylene glycol, propylene glycol, etc. having a number average molecular weight of about 500 to 2,000.

As the polyol having a hydrophilic group, the same polyol as the polyol having a hydrophilic group exemplified as the polyol usable for producing the polyurethane (A) can be used.

As polyols that can be used for producing the polyurethane (B), other polyols can be used in addition to those mentioned above, if necessary.

As the polyisocyanate that reacts with the polyol containing the polyether polyol, etc., the same polyisocyanates as exemplified as polyols that can be used in the production of the polyurethane (A) can be used.

In particular, when the ink of the present invention is used for printing on fabrics such as clothes, the polyisocyanate may be aliphatic or aliphatic such as isophorone diisocyanate or dicyclohexylmethane diisocyanate, in order to further improve the texture of printed matter. Preference is given to using diisocyanates containing cyclic structures.

When using a chain extender when producing the polyurethane (B), for example, ethylene glycol other than polyamine, diethylene glycol, triethylene glycol, propylene glycol, 1,3-propanediol, 1,3-butanediol , 1,4-butanediol, hexamethylene glycol, neopentyl glycol, saccharose, methylene glycol, glycerin, sorbitol and other glycols; bisphenol A, 4,4'-dihydroxydiphenyl, 4,4'-dihydroxydiphenyl ether, 4, Phenols such as 4'-dihydroxydiphenylsulfone, hydrogenated bisphenol A, and hydroquinone, water, and the like can be used.

The ink of the present invention may contain, in addition to the polyurethane (A) and polyurethane (B), other binders as required.

As the binder, for example, acrylic resin can be used. The acrylic resin is not particularly limited, and homopolymers or copolymers of (meth)acrylate, copolymers of (meth)acrylate and other vinyl monomers, and the like can be used.

Next, the solvent (C) used in the present invention will be explained.

As the solvent (C), for example, water alone or a mixed solvent of water and an organic solvent (F) described below can be used.

As the water, specifically, pure water or ultrapure water such as ion-exchanged water, ultrafiltrated water, reverse osmosis water, distilled water, etc. can be used.

The solvent (C) is preferably used in a range of 50% to 95% by mass based on the total amount of the ink, and is preferably used in a range of 65% to 95% by mass when drying near the ink nozzle. We developed an ink that prevents the ink from drying out, makes it easy to adjust the drying speed after landing on the recording medium, and allows for the production of clear printed matter with a good texture, especially when used for printing on fabric. It is particularly preferable for obtaining

As the organic solvent (F), for example, glycerin, diglycerin, polyglycerin, diglycerin fatty acid ester, polyoxypropylene (n) polyglyceryl ether, polyoxyethylene (n) polyglyceryl ether, etc. can be used.

In addition to the above-mentioned organic solvents, examples of the organic solvent (F) include acetone, methyl ethyl ketone, methyl butyl ketone, methyl isobutyl ketone, methanol, ethanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, and 2-methoxy. Ethanol, tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, dimethylformamide, N-methylpyrrolidone, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, polyethylene glycol, polypropylene glycol, butanediol, Pentanediol, hexanediol and similar diols, propylene glycol laurate, diethylene glycol monoethyl, diethylene glycol monobutyl ether, diethylene glycol monohexyl ether, propylene glycol ether, dipropylene glycol ether, cellosolve containing triethylene glycol ether, methanol , ethanol, isopropyl alcohol, 1-propanol, 2-propanol, butyl alcohol such as 1-butanol and 2-butanol, pentyl alcohol, and alcohols similar to these, sulfolane; lactones such as γ-butyrolactone; N-(2 -Hydroxyethyl) pyrrolidone and other lactams can be used alone or in combination of two or more.

In addition to the above-mentioned organic solvents, examples of the organic solvent (F) include 3-methoxy-1-butanol, 3-methyl-3-methoxy-1-butanol, 3-methoxy-3-methyl-1-butyl acetate, and ethylene. Glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol monoisobutyl ether, ethylene glycol-t-butyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether , one or more water-soluble organic solvents such as propylene glycol monomethyl ether acetate, diethylene glycol dimethyl ether, diethylene glycol methyl ethyl ether, diethylene glycol diethyl ether, dipropylene glycol dimethyl ether, 4-methoxy-4-methyl-2-pentanone, ethyl lactate, etc. Can be used in combination.

As the organic solvent (F), among those mentioned above, it is preferable to use glycerin, diglycerin, polyglycerin, diglycerin fatty acid ester, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, and glycerin It is preferable to use a combination of ink and propylene glycol to obtain an ink that easily penetrates into a recording medium such as fabric and dries, and that can prevent drying and coagulation in a nozzle or filter in an ink circulation type inkjet head.

The ink of the present invention may contain, in addition to the polyurethane (A), the polyurethane (B), and the solvent (C), a coloring material (D) if necessary. It is preferable that the polyurethane (A), the polyurethane (B), and the coloring material (D) exist in a dissolved or dispersed state in the solvent (C) such as water.

As the coloring material (D), known and commonly used pigments, dyes, etc. can be used. Among these, it is preferable to use pigments in order to produce printed matter with excellent weather resistance. Further, as the coloring material (D), a coloring agent in which the pigment is coated with a resin can also be used.

The pigment is not particularly limited, and organic or inorganic pigments commonly used in conventional screen printing and aqueous inkjet recording inks can be used.

Further, as the pigment, either a non-acid-treated pigment or an acid-treated pigment can be used, and it can be used either in the form of a dry powder or a wet cake.

As the inorganic pigment, for example, iron oxide, titanium oxide, carbon black produced by a method such as a contact method, a furnace method, or a thermal method can be used.

Examples of the organic pigments include azo pigments (including azo lakes, insoluble azo pigments, condensed azo pigments, chelate azo pigments, etc.), polycyclic pigments (for example, phthalocyanine pigments, perylene pigments, perinone pigments, anthraquinone pigments, quinacridone pigments, and dioxazine). Pigments, thioindigo pigments, isoindolinone pigments, quinofularone pigments, etc.), lake pigments (for example, basic dye type chelates, acidic dye type chelates, etc.), nitro pigments, nitroso pigments, aniline black, etc. can be used.

As a specific example of the pigment, if it is a pigment used for black ink, No. 1 manufactured by Mitsubishi Chemical Corporation is used. 2300, No. 2200B, No. 900, No. 980, No. 960, No. 950, No. 33, No. 40, No. 45, No. 45L, No. 52, HCF88, MCF88, MA7, MA8, MA100, etc., Raven5750, Raven5250, Raven5000, Raven3500, Raven1255, Raven700, etc. manufactured by Columbia, Regal 400R, Regal 33, manufactured by Cabot. 0R, Regal 660R, Mogul L, Mogul 700, Monarch800, Monarch880, Monarch900, Monarch1000, Monarch1100, Monarch1300, Monarch1400 etc. are Degussa's Color Black FW1, FW2, FW2V, FW18, FW200, S150, S160, S170, Printex 35, Carbon blacks such as Special Black U, Special Black V, Special Black 1400U, Special Black 6, Special Black 5, Special Black 4, Special Black 4A, NIPEX150, NIPEX160, NIPEX170, and NIPEX180 can be used.

Specific examples of pigments used in yellow ink include C.I. I. Pigment Yellow 1, 2, 12, 13, 14, 16, 17, 73, 74, 75, 83, 93, 95, 97, 98, 109, 110, 114, 120, 128, 129, 138, 150, 151, 154, 155, 174, 180, 185 and the like.

Specific examples of pigments used in magenta ink include C.I. I. Pigment Violet 19, C. I. Pigment Red 5, 7, 12, 48 (Ca), 48 (Mn), 57 (Ca), 57:1, 112, 122, 123, 146, 168, 176, 184, 185, 202, 209 and these pigments Examples include mixtures or solid solutions of at least two or more pigments selected from the following.

Specific examples of pigments used in cyan ink include C.I. I. Pigment Blue 1, 2, 3, 15, 15:3, 15:4, 15:6, 16, 22, 60, 63, 66 and the like.

Specific examples of pigments used in red ink include C.I. I. One or more selected from the group consisting of Pigment Red 17, 49:2, 112, 149, 150, 177, 178, 179, 188, 254, 255 and 264 are preferably used.

Specific examples of pigments used in orange ink include C.I. I. Pigment Orange 1, 2, 5, 7, 13, 14, 15, 16, 24, 34, 36, 38, 40, 43, 63, 64, 71, 73, 81 and the like.

Specific examples of pigments used in green ink include C.I. I. Pigment Green 7, 10, 36, 58, 59 and the like.

Specific examples of pigments used in violet ink include C.I. I. Pigment Violet 19, 23, 32, 33, 36, 38, 43, 50 and the like.

Specific examples of pigments that can be used in white ink include silicas such as alkaline earth metal sulfates, carbonates, finely divided silicic acid, synthetic silicates, calcium silicate, alumina, alumina hydrate, Examples include titanium oxide, zinc oxide, talc, and clay. These may be surface-treated.

As the pigment, the pigments listed above can be used alone or in combination of two or more.

In order to stably exist the pigment in the ink, it is preferable that measures are taken to disperse it well in an aqueous medium such as water.

Examples of such means include (i) dispersing the pigment together with a pigment dispersant in an aqueous medium such as water using the dispersion method described below; and (ii) dispersing groups (hydrophilic functional groups and/or Examples include a method of dispersing and/or dissolving a self-dispersing pigment in which a salt thereof is bound directly or indirectly through an alkyl group, an alkyl ether group, an aryl group, etc., in an aqueous medium such as water.

As the self-dispersing pigment, for example, a pigment in which a dispersibility-imparting group or an active species having a dispersibility-imparting group is bonded (grafted) to the surface of the pigment is used by subjecting the pigment to physical treatment or chemical treatment. be able to. The self-dispersing pigment can be processed, for example, by vacuum plasma treatment, oxidation treatment with hypohalous acid and/or hypohalite salt, oxidation treatment with ozone, or wet oxidation method in which the pigment surface is oxidized with an oxidizing agent in water. Alternatively, it can be produced by a method in which p-aminobenzoic acid is bonded to the pigment surface to bond a carboxyl group via a phenyl group.

Since the aqueous ink containing the self-dispersing pigment does not need to contain the pigment dispersant, there is almost no foaming caused by the pigment dispersant, and it is easy to prepare an ink with excellent ejection stability. In addition, water-based inks containing self-dispersing pigments are easy to handle and suppress the significant increase in viscosity caused by pigment dispersants, making it possible to contain more pigment and producing printed matter with high print density. It can be used for.

As the self-dispersing pigment, it is also possible to use commercially available products, such as Microjet CW-1 (trade name; manufactured by Orient Chemical Industry Co., Ltd.), CAB-O-JET200, CAB-O-JET300 (trade name; manufactured by Cabot Corporation) is exemplified.

In order to maintain the excellent dispersion stability of the coloring material (D) and to improve the print density and washing resistance of the printed matter, the coloring material (D) should be present in an amount of 1% by mass to 1% by mass based on the total amount of the ink. It is preferably used in a range of 20% by mass, and more preferably in a range of 2% by mass to 10% by mass.

(pigment dispersant)
The pigment dispersant can be suitably used when a pigment is used as the coloring material (D).

Examples of the pigment dispersant include polyvinyl alcohols, polyvinylpyrrolidones, acrylic resins such as acrylic acid-acrylic acid ester copolymers, styrene-acrylic acid copolymers, styrene-methacrylic acid copolymers, and styrene-methacrylic acid. - Styrene-acrylic resins, styrene-maleic acid copolymers, such as acrylic ester copolymers, styrene-α-methylstyrene-acrylic acid copolymers, styrene-α-methylstyrene-acrylic acid-acrylic ester copolymers Aqueous resins of polymers, styrene-maleic anhydride copolymers, vinylnaphthalene-acrylic acid copolymers, and salts of the aforementioned aqueous resins can be used. The pigment dispersants include the Ajisper PB series (products of Ajinomoto Fine-Techno Co., Ltd.), the Disperbyk series of BYK Chemie Japan Co., Ltd., the EFKA series of BASF, the SOLSPERSE series of Japan Lubrizol Co., Ltd., and the Evonik Co., Ltd. TEGO series etc. can be used.

As the pigment dispersant, the polymer (E) described below can be used, since it can significantly reduce coarse particles and, as a result, provide good ejection stability required when ejecting the ink by an inkjet method. is preferred.

As the polymer (E), a polymer having an anionic group can be used, and in particular, one having a solubility in water of 0.1 g/100 ml or less, and having a basic compound containing the anionic group. It is preferable to use a polymer having a number average molecular weight within the range of 1000 to 6000 and capable of forming fine particles in water when the sum ratio is 100%.

The solubility of the polymer (E) in water was defined as follows. That is, 0.5 g of polymer (E), whose particle size was adjusted to a range of 250 μm to 90 μm using sieves with openings of 250 μm and 90 μm, was sealed in a bag made of 400 mesh wire mesh, immersed in 50 ml of water, and heated at 25°C. The mixture was left stirring gently at room temperature for 24 hours. After immersion for 24 hours, the 400-mesh wire mesh encapsulating polymer (E) was dried for 2 hours in a dryer set at 110°C. The change in weight of a 400-mesh wire mesh encapsulating polymer (E) before and after immersion in water was measured, and the solubility was calculated using the following formula.

Further, in the present invention, whether or not fine particles were formed in water when the neutralization rate of the anionic group with the basic compound was set to 100% was determined as follows.
(1) The acid value of the polymer (E) is measured in advance by an acid value measuring method based on JIS test method K 0070-1992. Specifically, 0.5 g of polymer (E) is dissolved in tetrahydrofuran, and the acid value is determined by titration with a 0.1 M alcoholic potassium hydroxide solution using phenolphthalein as an indicator.
(2) After adding 1 g of polymer (E) to 50 ml of water, add 0.1 mol/L aqueous potassium hydroxide solution to neutralize the obtained acid value by 100% to achieve 100% neutralization.
(3) The 100% neutralized liquid was irradiated with ultrasonic waves at a temperature of 25°C for 2 hours in an ultrasonic cleaner (SND Ultrasonic Cleaner US-102, 38kHz self-oscillation). Leave it at room temperature for the next 24 hours.

After standing for 24 hours, the sample liquid sampled from a depth of 2 cm from the liquid surface was measured using a dynamic light scattering particle size distribution analyzer (manufactured by Nikkiso Co., Ltd., dynamic light scattering particle size analyzer ``Micro''). The presence of fine particles is confirmed by determining whether light scattering information due to the formation of fine particles can be obtained using a truck particle size distribution analyzer (UPA-ST150).

In order to further improve the stability in water of the fine particles formed by the polymer (E) used in the present invention, the particle size of the fine particles is preferably in the range of 5 nm to 1000 nm, and preferably in the range of 7 nm to 700 nm. More preferably, the range is from 10 nm to 500 nm. Further, the narrower the particle size distribution of the fine particles, the better the dispersion stability tends to be, but even when the particle size distribution is wide, an ink with better dispersion stability than conventional ones can be obtained. Note that the particle size and particle size distribution are measured using a dynamic light scattering particle size distribution measuring device (Nikkiso Co., Ltd.'s dynamic light scattering particle size measuring device "Microtrack Particle Size Distribution Meter UPA") in the same way as the method for measuring fine particles. -ST150'').

The neutralization rate of the polymer (E) used in the present invention was determined by the following formula.

Further, the acid value of the polymer (E) was measured based on JIS test method K 0070-1992. Specifically, it was determined by dissolving 0.5 g of a sample in tetrahydrofuran and titrating with a 0.1M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

The number average molecular weight of the polymer (E) is preferably in the range of 1,000 to 6,000, more preferably 1,300 to 5,000, and preferably 1,500 to 4,500 as the pigment, etc. in the solvent (C). It is more preferable in terms of effectively suppressing aggregation of the coloring material (D) and obtaining an ink having good dispersion stability of the coloring material (D).

Note that the number average molecular weight is a polystyrene equivalent value measured by GPC (gel permeation chromatography), and specifically, a value measured under the following conditions.

(Method for measuring number average molecular weight (Mn))
It was measured by gel permeation chromatography (GPC) under the following conditions.
Measuring device: High-speed GPC device (“HLC-8220GPC” manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were used by connecting them in series.

"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 Book "TSKgel G2000" (7.8mm I.D. x 30cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40℃
Eluent: Tetrahydrofuran Flow rate: 1.0 mL/min Injection volume: 100 μL (Tetrahydrofuran solution with sample concentration 0.4% by mass)
Standard sample: A calibration curve was created using the following standard polystyrene.
(Standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
“TSKgel Standard Polystyrene F-1” manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

The surface tension of the ink containing the polymer (E) is preferably 30 dyn/cm or more, more preferably 40 dyn/cm or more, and 65 dyn/cm to 75 dyn/cm, which is close to the surface tension of water. It is particularly preferred to use The above surface tension is determined by adding 1 g of polymer (E) to water, then adding 0.1 mol/L aqueous potassium hydroxide solution that neutralizes the resulting acid value to 100%, resulting in a 100% neutralized polymer solution. This is the value measured for.

As the polymer (E), it is possible to use a polymer that is insoluble or poorly soluble in water in an unneutralized state and forms fine particles in a 100% neutralized state, and has a hydrophilic group. There are no particular limitations as long as the polymer has a hydrophobic group in one molecule in addition to a certain anionic group.

Examples of such polymers include block polymers having a polymer block having a hydrophobic group and a polymer block having an anionic group. In the polymer (E), the number of anionic groups and the solubility in water are not necessarily specified by the acid value or the number of anionic groups at the time of polymer design. Even if there is, those with low molecular weight tend to have high solubility in water, and those with high molecular weight tend to have low solubility in water. For this reason, in the present invention, the polymer (E) is specified by its solubility in water.

The polymer (E) may be a homopolymer, but is preferably a copolymer, and may be a random polymer, a block polymer, or an alternating polymer, but is especially a block polymer. It is preferable. Furthermore, although the polymer may be a branched polymer, it is preferably a linear polymer.

Further, the polymer (E) is preferably a vinyl polymer from the viewpoint of design freedom, and methods for producing a vinyl polymer having the desired molecular weight and solubility characteristics in the present invention include living radical polymerization, living cationic polymerization, etc. It is preferable to produce by using "living polymerization" such as , living anionic polymerization.

Among these, the polymer (E) is preferably a vinyl polymer produced using a (meth)acrylate monomer as one of the raw materials, and methods for producing such a vinyl polymer include living radical polymerization and living anionic polymerization. is preferred, and living anionic polymerization is preferred from the viewpoint of allowing more precise design of the molecular weight of the block polymer and each segment.

The polymer (E) produced by living anionic polymerization is specifically a polymer represented by general formula (3).

In the general formula (3), A ¹ represents an organolithium initiator residue, A ² represents a polymer block having a hydrophobic group, A ³ represents a polymer block containing an anionic group, and n is 1 to 5. B represents an aromatic group or an alkyl group.

In general formula (3), A ¹ represents an organolithium initiator residue. Specific examples of organolithium initiators include methyllithium, ethyllithium, propyllithium, butyllithium (n-butyllithium, sec-butyllithium, iso-butyllithium, tert-butyllithium, etc.), pentyllithium, hexyllithium, Alkyllithium such as methoxymethyllithium and ethoxymethyllithium; phenylalkylenelithium such as benzyllithium, α-methylstyryllithium, 1,1-diphenyl-3-methylpentyllithium, 1,1-diphenylhexyllithium, and phenylethyllithium ; Alkenyllithium such as vinyllithium, allyllithium, propenyllithium, butenyllithium; Alkynyllithium such as ethynyllithium, butynyllithium, pentynyllithium, hexynyllithium; aryllithium such as phenyllithium, naphthyllithium; 2-thienyl Examples include heterocyclic lithium such as lithium, 4-pyridyllithium, and 2-quinolyllithium; alkyllithium magnesium complexes such as tri(n-butyl)magnesiumlithium and trimethylmagnesiumlithium.

In the organolithium initiator, the bond between the organic group and lithium is cleaved to form an active terminal on the organic group side, from which polymerization is initiated. Therefore, an organic group derived from organolithium is bonded to the end of the obtained polymer. In the present invention, the organolithium-derived organic group bonded to the polymer terminal is referred to as an organolithium initiator residue. For example, in the case of a polymer using methyllithium as an initiator, the organolithium initiator acid group will be a methyl group, and in the case of a polymer using butyllithium as an initiator, the organolithium initiator acid group will be a butyl group.

In the general formula (3), A ² represents a polymer block having a hydrophobic group. ^A2 is preferably a group that is highly adsorbed to the pigment when it comes into contact with the pigment, in addition to the purpose of achieving an appropriate solubility balance as described above, and from that point of view, ^A2 is an aromatic ring or a heterocyclic ring. It is preferable that it is a polymer block of a monomer having.
Specifically, a polymer block of a monomer having an aromatic ring or a heterocycle is a polymer block made by homopolymerizing or copolymerizing a monomer having an aromatic ring such as a styrene monomer, or a monomer having a heterocycle such as a vinylpyridine monomer. It is a polymer block of homopolymer or copolymer obtained by

Monomers having an aromatic ring include styrene, p-tert-butyl, styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, p-tert-butoxystyrene, m-tert-butoxystyrene, p-tert-butoxystyrene, Styrenic monomers such as -tert-(1-ethoxymethyl)styrene, m-chlorostyrene, p-chlorostyrene, p-fluorostyrene, α-methylstyrene, p-methyl-α-methylstyrene, vinylnaphthalene, Examples include vinylanthracene.

Examples of monomers having a heterocycle include vinylpyridine monomers such as 2-vinylpyridine and 4-vinylpyridine. These monomers can be used alone or in combination of two or more.

In the general formula (3), A ³ represents a polymer block containing an anionic group. ^A3 has the purpose of imparting appropriate solubility as described above, as well as the purpose of imparting dispersion stability in water when formed into a pigment dispersion.
Examples of the anionic group in the polymer block ^A3 include a carboxyl group, a sulfonic acid group, and a phosphoric acid group. Among these, carboxyl groups are preferred because of their ease of preparation, wide variety of monomers, and ease of acquisition. Further, two carboxyl groups may be intramolecularly or intermolecularly dehydrated and condensed to form an acid anhydride group.

The method of introducing the anionic group in ^A3 is not particularly limited. For example, when the anionic group is a carboxyl group, a homopolymer obtained by homopolymerizing (meth)acrylic acid or copolymerizing with other monomers or It may be a polymer block (PB1) of a copolymer, or a homopolymer obtained by homopolymerizing or copolymerizing with other monomers a (meth)acrylate having a protecting group that can be regenerated into an anionic group by deprotection. The polymer block (PB2) may be a polymer or copolymer in which some or all of the protecting groups that can be regenerated into anionic groups are regenerated into anionic groups.

Note that (meth)acrylic acid used in the polymer block ^A3 represents a general term for acrylic acid and methacrylic acid, and (meth)acrylate represents a general term for acrylate and methacrylate.

(Meth)acrylic acid and (meth)acrylates include (meth)acrylic acid, methyl (meth)acrylate, ethyl (meth)acrylate, iso-propyl (meth)acrylate, and (meth)acrylate. Allyl acrylate, n-butyl (meth)acrylate, iso-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, n-amyl (meth)acrylate, ( iso-amyl meth)acrylate, n-hexyl (meth)acrylate, n-octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-lauryl (meth)acrylate, n-(meth)acrylate -Tridecyl, n-stearyl (meth)acrylate, phenyl (meth)acrylate, benzyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-tert-butylcyclohexyl (meth)acrylate, (meth)acrylic acid Isobornyl, tricyclodecanyl (meth)acrylate, dicyclopentadienyl (meth)acrylate, adamantyl (meth)acrylate, glycidyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, (meth)acrylate 2-methoxyethyl acid, 2-ethoxyethyl (meth)acrylate, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, trifluoroethyl (meth)acrylate, tetrafluoropropyl (meth)acrylate , pentafluoropropyl (meth)acrylate, octafluoropentyl (meth)acrylate, pentadecafluorooctyl (meth)acrylate, heptadecafluorodecyl (meth)acrylate, N,N-dimethyl (meth)acrylamide, ( meth)acryloylmorpholine, (meth)acrylonitrile, polyethylene glycol (meth)acrylate, polypropylene glycol (meth)acrylate, polyethylene glycol-polypropylene glycol (meth)acrylate, polyethylene glycol-polybutylene glycol (meth)acrylate, polypropylene glycol-polybutylene Glycol (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, ethoxypolyethylene glycol (meth)acrylate, butoxypolyethylene glycol (meth)acrylate, octoxypolyethylene glycol (meth)acrylate, lauroxypolyethylene glycol (meth)acrylate, stearoxy Examples include polyalkylene oxide group-containing (meth)acrylates such as polyethylene glycol (meth)acrylate, phenoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, and octoxypolyethylene glycol-polypropylene glycol (meth)acrylate. These monomers can be used alone or in combination of two or more.

In the living anionic polymerization method, if the monomer used is a monomer having a group with active protons such as an anionic group, the active terminal of the living anionic polymerization polymer immediately reacts with the group having active protons and is deactivated. No polymer is obtained. In living anionic polymerization, it is difficult to directly polymerize a monomer that has a group that has an active proton, so the group that has an active proton is polymerized in a protected state, and then the protecting group is deprotected to create a monomer that has an active proton. Preferably, the groups are regenerated.

For this reason, in the polymer block ^A3 , it is preferable to use a monomer containing a (meth)acrylate having a protecting group that can be regenerated into an anionic group by deprotection. By using this monomer, the above-mentioned inhibition of polymerization can be prevented during polymerization. Further, the anionic group protected by a protecting group can be regenerated into an anionic group by deprotecting the block polymer after obtaining the block polymer.

For example, when the anionic group is a carboxyl group, the carboxyl group can be regenerated by esterifying the carboxyl group and deprotecting it by hydrolysis or the like as a subsequent step. In this case, the protecting group convertible to a carboxyl group is preferably a group having an ester bond, such as a primary alkoxycarbonyl group such as a methoxycarbonyl group, an ethoxycarbonyl group, an n-propoxycarbonyl group, or an n-butoxycarbonyl group. ; Secondary alkoxycarbonyl groups such as isopropoxycarbonyl group and sec-butoxycarbonyl group; Tertiary alkoxycarbonyl group such as t-butoxycarbonyl group; Phenylalkoxycarbonyl group such as benzyloxycarbonyl group; Ethoxyethylcarbonyl group, etc. Examples include alkoxyalkylcarbonyl groups.

When the anionic group is a carboxyl group, monomers that can be used include methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec. -Butyl (meth)acrylate, isobutyl (meth)acrylate, t-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, decyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate (lauryl (meth)acrylate) ) acrylate), tridecyl (meth)acrylate, pentadecyl (meth)acrylate, hexadecyl (meth)acrylate, heptadecyl (meth)acrylate, octadecyl (meth)acrylate (stearyl (meth)acrylate), nonadecyl (meth)acrylate, icosanyl (meth)acrylate ) acrylate; phenylalkylene (meth)acrylates such as benzyl (meth)acrylate; and alkoxyalkyl (meth)acrylates such as ethoxyethyl (meth)acrylate. These (meth)acrylates can be used alone or in combination of two or more. Furthermore, among these (meth)acrylates, it is preferable to use t-butyl (meth)acrylate and benzyl (meth)acrylate because the conversion reaction into a carboxyl group is easy. Furthermore, considering industrial availability, t-butyl (meth)acrylate is more preferred.

In the general formula (3), B represents an aromatic group or an alkyl group having 1 to 10 carbon atoms. Further, n represents an integer from 1 to 5.

In the living anionic polymerization method, when attempting to directly polymerize a (meth)acrylate monomer onto the active end of a styrenic polymer with strong nucleophilic properties, polymerization may not be possible due to nucleophilic attack on the carbonyl carbon. Therefore, when polymerizing the (meth)acrylate monomer to A ¹ -A ² , a reaction regulator is used to adjust the nucleophilicity, and then the (meth)acrylate monomer is polymerized. B in general formula (3) is a group derived from the reaction regulator. Specific examples of the reaction regulator include diphenylethylene, α-methylstyrene, p-methyl-α-methylstyrene, and the like.

The living anionic polymerization method can be carried out by a batch method as used in conventional free radical polymerization by adjusting the reaction conditions, and can also be carried out by a continuous polymerization method using a microreactor. In a microreactor, the polymerization initiator and monomer have good miscibility, so the reactions start at the same time, the temperature is uniform, and the polymerization rate can be made uniform, so the molecular weight distribution of the produced polymer can be narrowed. At the same time, since the growing ends are stable, it becomes easy to produce a block copolymer in which both components of the block do not mix. Furthermore, since the reaction temperature is well controllable, side reactions can be easily suppressed.

A general method of living anionic polymerization using a microreactor will be described with reference to FIG. 1, which is a schematic diagram of a microreactor.
The first monomer and a polymerization initiator for starting polymerization are transferred from tube reactors P1 and P2 (7 and 8 in Figure 1), respectively, to a T-shaped micromixer M1 (Figure 1) equipped with a channel capable of mixing a plurality of liquids. 1 of 1), and the first monomer is subjected to living anion polymerization in the T-shaped micromixer M1 to form a first polymer (Step 1).

Next, the obtained first polymer was transferred to a T-shaped micromixer M2 (2 in Fig. 1), and in the same mixer M2, the growing end of the obtained polymer was transferred to a tube reactor P3 (Fig. 1). The reaction control agent introduced from step 9) traps and controls the reaction (step 2).
In addition, at this time, it is possible to control the number of n in the general formula (3) by the type and amount of the reaction regulator used.

Next, the first polymer subjected to reaction control in the T-shaped micromixer M2 is transferred to the T-shaped micromixer M3 (3 in FIG. 1), and in the same mixer M3, the first polymer is transferred from the tube reactor P4. The introduced second monomer and the first polymer subjected to the reaction control are continuously subjected to living anionic polymerization (Step 3).

Thereafter, the reaction is quenched with a compound having active protons, such as methanol, to produce a block copolymer.

When the polymer (E) represented by the general formula (3) of the present invention is produced in the microreactor, a monomer having an aromatic ring or a heterocycle is used as the first monomer, and an organic By reacting with a lithium initiator, a polymer block of the monomer having an aromatic ring or a heterocycle of ^A2 (at one end of the polymer block ^A2 , an organic group that is a residue of the organolithium initiator of ^A1 ) is formed. ) is obtained.
Next, after adjusting the reactivity of the growing end using a reaction regulator, a monomer containing a (meth)acrylate having a renewable protecting group on the anionic group is reacted with the second monomer to form a polymer block. get.

Thereafter, the aforesaid ^A3 , that is, a polymer block containing an anionic group, is obtained by regenerating it into an anionic group by a deprotection reaction such as hydrolysis.

A method for regenerating the ester bond of the protective group that can be regenerated into the anionic group into an anionic group by a deprotection reaction such as hydrolysis will be described in detail.

The hydrolysis reaction of ester bonds proceeds under both acidic and basic conditions, but the conditions differ slightly depending on the group having an ester bond. For example, if the group having an ester bond is a primary alkoxycarbonyl group such as a methoxycarbonyl group or a secondary alkoxycarbonyl group such as an isopropoxycarbonyl group, a carboxyl group is obtained by hydrolysis under basic conditions. be able to. At this time, examples of the basic compound used under basic conditions include metal hydroxides such as sodium hydroxide and potassium hydroxide.

Furthermore, when the group having an ester bond is a tertiary alkoxycarbonyl group such as a t-butoxycarbonyl group, a carboxyl group can be obtained by hydrolysis under acidic conditions. At this time, examples of the acidic compound used under acidic conditions include mineral acids such as hydrochloric acid, sulfuric acid, and phosphoric acid; breathed acids such as trifluoroacetic acid; and Lewis acids such as trimethylsilyl triflate. The reaction conditions for hydrolyzing a t-butoxycarbonyl group under acidic conditions are disclosed, for example, in "Synthesis of Organic Compounds IV, Experimental Chemistry Course 16, 5th Edition, edited by the Chemical Society of Japan."

Furthermore, as a method for converting a t-butoxycarbonyl group into a carboxyl group, a method using a cation exchange resin in place of the above-mentioned acid may also be mentioned. Examples of the cation exchange resin include resins having acid groups such as carboxyl groups (-COOH) and sulfo groups (-SO ₃ H) in side chains of polymer chains. Among these, a strongly acidic cation exchange resin having a sulfo group in the side chain of the resin is preferred because it can speed up the reaction. Commercially available cation exchange resins that can be used in the present invention include, for example, strongly acidic cation exchange resin "Amberlite" manufactured by Organo Co., Ltd. The amount of this cation exchange resin used is preferably in the range of 5 parts by mass to 200 parts by mass, and 10 parts by mass, based on 100 parts by mass of the polymer represented by the general formula (3). The range of 100 parts by mass is more preferable.

Furthermore, when the group having an ester bond is a phenylalkoxycarbonyl group such as a benzyloxycarbonyl group, it can be converted to a carboxyl group by performing a hydrogenation-reduction reaction. At this time, the reaction conditions include hydrogen gas as a reducing agent at room temperature in the presence of a palladium catalyst such as palladium acetate, whereby the phenylalkoxycarbonyl group can be quantitatively regenerated into a carboxyl group.

As mentioned above, the reaction conditions for conversion to a carboxyl group differ depending on the type of group having an ester bond, so for example, if t-butyl (meth)acrylate and n-butyl (meth)acrylate are used as the raw material for ^A3 , The polymer obtained by copolymerization has a t-butoxycarbonyl group and an n-butoxycarbonyl group. Here, under acidic conditions where the t-butoxycarbonyl group is hydrolyzed, the n-butoxycarbonyl group is not hydrolyzed, so it is possible to selectively hydrolyze only the t-butoxycarbonyl group and deprotect it to the carboxyl group. becomes. Therefore, the acid value of the hydrophilic block (A ³ ) can be adjusted by appropriately selecting a monomer containing a (meth)acrylate having a renewable protecting group in the anionic group that is the raw material monomer for A ³ .

Further, in the polymer (E) represented by the general formula (3), the polymer block (A ² ) and the polymer block (A ³ ) are not a random copolymer in which they are randomly arranged and bonded, but the polymer block is A block copolymer in which the pigment is regularly bonded in clusters of a certain length is advantageous in improving the stability of the aqueous pigment dispersion in which the pigment is dispersed in water by the polymer (E). be. The aqueous pigment dispersion is a raw material used for producing ink, and is a liquid in which the pigment is dispersed in water at a high concentration using the polymer (E). The molar ratio A ² :A ³ of the polymer block (A ² ) and the polymer block (A ³ ) is preferably in the range of 100:10 to 100:500, and A ² :A ³ =100:10 to 100: 450, it is possible to maintain the good ejection stability required when ejecting ink using an inkjet method, for example, and to obtain an ink that can produce printed matter with even better color development. is more preferable.

Further, in the polymer (E) represented by the general formula (3), the number of monomers having aromatic rings or heterocycles constituting the polymer block (A ² ) is preferably in the range of 5 to 40, and preferably in the range of 6 to 30. is more preferred, and a range of 7 to 25 is most preferred. The number of anionic groups constituting the polymer block (A ³ ) is preferably in the range of 3 to 20, more preferably in the range of 4 to 17, and most preferably in the range of 5 to 15.
The molar ratio A ² :A ³ of the polymer block (A 2 ) and the polymer block ( ^{A 3} ) is determined by the number of moles having aromatic rings or heterocycles that constitute the polymer block (A ² ) and (A ³ ). The molar ratio of the number of moles of anionic groups is preferably 100:7.5 to 100:400.

Further, the acid value of the polymer (E) represented by the general formula (3) is preferably 40 mgKOH/g to 400 mgKOH/g, more preferably 40 mgKOH/g to 300 mgKOH/g, and more preferably 40 mgKOH/g to 190 mgKOH/g. For example, in order to obtain an ink that can maintain the good ejection stability required when ejecting ink using an inkjet method and that can produce printed matter with even better scratch resistance, etc. More preferred.

The acid value of the polymer in the present invention was determined by the same acid value measuring method as the method for measuring fine particles of polymer (E).

In the ink, the anionic group of the polymer (E) is preferably neutralized.

As the basic compound for neutralizing the anionic group of the polymer (E), any known and commonly used basic compound can be used, such as inorganic basic compounds such as alkali metal hydroxides such as sodium hydroxide and potassium hydroxide. Substances and organic basic compounds such as ammonia, triethylamine, alkanolamines can be used.

The neutralized amount of the polymer (E) present in the aqueous pigment dispersion does not need to be 100% neutralized with respect to the acid value of the polymer. Specifically, the neutralization rate of the polymer (E) is preferably 20% to 200%, more preferably 80% to 150%.

In addition to the above-mentioned components, the ink of the present invention may optionally contain other additives such as surfactants, sugars, preservatives, viscosity modifiers, pH adjusters, chelating agents, antioxidants, and ultraviolet absorbers. can be used.

The surfactant can be used to improve the leveling properties of the ink by lowering the surface tension of the ink. Further, the surfactant can prevent the occurrence of mottling in printed matter by allowing the ink ejected from the ejection port of the inkjet head to spread well on the surface of the fabric after landing on the fabric.

As the surfactant, various anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, etc. can be used, and anionic surfactants, nonionic surfactants It is preferable to use

Examples of the anionic surfactant include alkylbenzene sulfonates, alkylphenyl sulfonates, alkylnaphthalene sulfonates, higher fatty acid salts, sulfuric ester salts of higher fatty acid esters, sulfonates of higher fatty acid esters, and higher alcohols. Examples include ether sulfate ester salts and sulfonates, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, etc. Specific examples of these include dodecylbenzenesulfonate, isopropylnaphthalenesulfonate, monobutylphenylphenol monosulfonate, monobutylphenylphenol sulfonate, dibutylphenylphenol disulfonate, and the like.

Examples of the nonionic surfactant include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, and glycerin fatty acid. ester, polyoxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, fatty acid alkylolamide, alkyl alkanolamide, acetylene glycol, oxyethylene adduct of acetylene glycol , polyethylene glycol, polypropylene glycol block copolymer, etc. Among these, polyoxyethylene nonylphenyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene dodecylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene Preferred are fatty acid esters, sorbitan fatty acid esters, polyoxyethylene sorbitan fatty acid esters, fatty acid alkylolamides, acetylene glycol, oxyethylene adducts of acetylene glycol, and polyethylene glycol polypropylene glycol block copolymers. Among these, acetylene glycol and oxyethylene adducts of acetylene glycol are more preferred because they reduce the contact angle of ink droplets with respect to the recording medium and provide good printed matter.

Other surfactants include silicone surfactants such as polysiloxane oxyethylene adducts; fluorine surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers. Agents; biosurfactants such as spicrisporic acid, rhamnolipid, and lysolecithin can also be used.

As the surfactant, it is preferable to use one having an HLB in the range of 4 to 20 in order to stably maintain a state in which the surfactant is dissolved in the ink having water as the main solvent.

The surfactant is preferably used in a range of 0.001% by mass to 2% by mass, and preferably in a range of 0.001% by mass to 1.5% by mass, based on the total amount of the ink. More preferably, it is used in a range of 0.1% by mass to 1.5% by mass. The inkjet ink containing the surfactant in the above range has good wettability of ejected droplets on the fabric surface, has sufficient wetting and spreading on the fabric, and has the effect of preventing the occurrence of mottling on printed matter. Preferred for playing. Furthermore, the ink containing the surfactant in the above range has the effect of improving the wettability to fabric.

Examples of the saccharides include monosaccharides and polysaccharides, such as glucose, mannose, fructose, ribose, xylose, arabinose, lactose, galactose, aldonic acid, glucitose, maltose, cellobiose, sucrose, trehalose, maltotriose, etc. Alginic acid and its salts, cyclodextrins, and celluloses can be used.

The preservatives include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, and 1,2-dibendisothiazolin-3-one (Arch Chemicals). Proxel GXL, Proxel XL-2, Proxel LV, Proxel AQ, Proxel BD20, Proxel DL) and the like.

Specific examples of the viscosity modifier include mainly water-soluble natural or synthetic polymers such as carboxymethylcellulose, sodium polyacrylate, polyvinylpyrrolidone, gum arabic, and starch.

Specific examples of the pH adjuster include collidine, imidazole, phosphoric acid, 3-(N-morpholino)propanesulfonic acid, tris(hydroxymethyl)aminomethane, boric acid, and the like.

Specific examples of the chelating agent include ethylenediaminetetraacetic acid, ethylenediaminediacetic acid, nitrilotriacetic acid, 1,3-propanediaminetetraacetic acid, diethylenetriaminepentaacetic acid, N-hydroxyethylethylenediaminetriacetic acid, iminodiacetic acid, and uramildiacetic acid. , 1,2-diaminocyclohexane-N,N,N',N'-tetraacetic acid, malonic acid, succinic acid, glutaric acid, maleic acid, and salts thereof (including hydrates).

Examples of the antioxidant or ultraviolet absorber include allophanates such as allophanate and methyl allophanate, biurets such as biuret, dimethylbiuret, and tetramethylbiuret, L-ascorbic acid and its salts, Tinuvin 328 manufactured by Ciba Geigy, etc. 900, 1130, 384, 292, 123, 144, 622, 770, 292, Irgacor252, 153, Irganox 1010, 1076, 1035, MD1024, or lanthanide oxides.

(Ink manufacturing method)
In the ink of the present invention, when the coloring material (D) is a pigment, an aqueous pigment dispersion containing the pigment at a high concentration is produced, and the aqueous pigment dispersion, the solvent (C), and the polyurethane ( It can be produced by mixing A), polyurethane (B), and other binder resins, surfactants, and additives as necessary.

Examples of the method for producing the aqueous pigment dispersion include the following methods (1) to (3).
(1) A method of preparing an aqueous pigment dispersion by adding a pigment to a mixture containing a dispersion resin and water, and then dispersing the pigment into the mixture using a stirring dispersion device.
(2) Knead the pigment and dispersion resin using a kneading machine such as two rolls or a mixer, add water and, if necessary, an organic solvent that is miscible with water to the obtained kneaded product, and add it to the stirring dispersion device. A method of preparing an aqueous pigment dispersion using.
(3) After adding the pigment to the solution obtained by dissolving the dispersion resin in an organic solvent that is compatible with water, such as methyl ethyl ketone or tetrahydrofuran, the pigment is dispersed in the organic solution using a stirring dispersion device. and then phase inversion emulsification using an aqueous medium such as water, followed by distilling off the organic solvent to prepare an aqueous pigment dispersion.

The kneading machine is not particularly limited, and includes, for example, a Henschel mixer, a pressure kneader, a Banbury mixer, an intensive mixer, a planetary mixer, a butterfly mixer, and the like.

As the stirring and dispersion device, for example, an ultrasonic homogenizer, a high-pressure homogenizer, a paint shaker, a ball mill, a roll mill, a sand mill, a sand grinder, a dyno mill, a dispermat, an SC mill, a nanomizer, etc. can be used alone or in combination of two or more types. .

As the aqueous pigment dispersion, it is preferable to use one containing 5% by mass to 60% by mass of pigment based on the total amount of the aqueous pigment dispersion, since it is possible to form printed matter with high image density and has excellent dispersion stability. It is preferable to use an aqueous pigment dispersion having a content of 10% by mass to 50% by mass.

In addition, since coarse particles contained in an aqueous pigment dispersion can cause deterioration of image characteristics, it is recommended to use an aqueous pigment dispersion from which coarse particles have been removed by centrifugation or filtration before or after producing ink. is preferred.

When producing the aqueous pigment dispersion, the dispersion step may be followed by an impurity removal step by ion exchange treatment or ultratreatment, followed by a post-treatment. Ion exchange treatment can remove ionic substances such as cations and anions (divalent metal ions, etc.), and ultratreatment can remove impurity-dissolved substances (residual substances during pigment synthesis, excess components in the dispersion composition). , resins not adsorbed to organic pigments, foreign substances, etc.) can be removed. The ion exchange treatment uses a known ion exchange resin. The ultratreatment may be performed using a known ultrafiltration membrane, either a normal type or a double capacity type.

As a method for mixing the aqueous pigment dispersion obtained by the above method, the polyurethane (A), the polyurethane (B), etc., for example, the aqueous dispersion of the polyurethane (A) and the polyurethane (B) may be mixed in advance. B) A method of producing a mixture with an aqueous dispersion, etc., and mixing the mixture and an aqueous pigment dispersion, or a method of producing a mixture of the aqueous pigment dispersion, an aqueous dispersion of the polyurethane (A), etc. After mixing the aqueous dispersion, a method may be mentioned in which other additives such as a surfactant are further mixed. ”

In the ink of the present invention obtained by the above method, in order to ensure sufficient image density and good dispersion stability of the pigment in the ink, the mass ratio of the pigment to the total amount of the ink ( It is preferable that the pigment concentration (pigment concentration) is 1% by mass to 20% by mass.

The pH of the ink is preferable in order to improve the storage stability and ejection stability of the ink, and to improve the wet spread, print density, and water fastness when printing on fabrics that are easily or poorly absorbent. is 7.0 or more, more preferably 7.5 or more, even more preferably 8.0 or more. The upper limit of the pH of the ink suppresses deterioration of the members (e.g., ink ejection opening, ink flow path, etc.) that constitute the ink application or ejection device, and reduces the effect when the ink adheres to the skin. It is preferably 11.0 or less, more preferably 10.0 or less, and even more preferably 9.5 or less.

The ink of the present invention obtained by the above method can be used, for example, in an inkjet printing method, a screen printing method, etc., preferably an inkjet printing method, and more preferably a printing method using an ink circulation type inkjet head. can.

The printing device equipped with the ink circulation type inkjet head has, for example, an ink inflow path and an ink outflow path in addition to the ink discharge nozzle, and the ink that flows out from the outflow path flows through the inflow path. An example of a printing apparatus includes a head having a circulation structure in which ink is supplied to the inkjet head again. Moreover, as the printing apparatus, one in which a filter is provided in the middle of the circulation structure can be suitably used.

It is preferable to use a filter with a pore diameter in the range of 5 μm to 20 μm, and using a filter with a pore diameter in the range of 5 μm to 10 μm is effective in removing foreign substances that may occur near the nozzle. It is preferable.

Examples of recording media that can be used when producing printed matter using the ink of the present invention and the above-described printing method or printing device include plain paper, coated paper, art paper, film, special paper for inkjet printing, and fabric. It will be done.

The ink of the present invention can be suitably used exclusively for printing on fabrics.

The fabric generally refers to a fabric made by weaving threads made of fibers such as cotton alternately in the vertical and horizontal directions. The ink of the present invention is suitable not only for fabrics in the general sense but also for media composed of fibers such as nonwoven fabrics and knitted fabrics. As the material, fabrics made of any natural fibers or synthetic fibers such as cotton, silk, wool, hemp, nylon, polyester, polyurethane, rayon, etc., or fabrics made by blending these can be used.

Examples of the printing method on the fabric include a method of printing the ink of the present invention on the fabric using, for example, a printing device equipped with an ink circulation type inkjet head.

In this case, it is preferable that the shortest distance between the ink ejection opening of the ink circulation type inkjet head and the fabric is set to 1 mm or more.

The shortest distance is the distance from the surface (x) having the ink ejection opening of the inkjet head to the position (y) where the perpendicular to the surface (x) (perpendicular assumed to the surface (x)) intersects with the fabric. (gap).

In the inkjet recording method applied in the method for manufacturing printed matter of the present invention, an inkjet recording apparatus having a configuration in which the shortest distance (gap) is 2 mm or more, preferably 3 mm or more can be used.

The shortest distance prevents the surface (recording surface) of the fabric from coming into contact with the ink ejection port, even if the fabric has large fuzz or unevenness, and prevents damage to the ink ejection port or damage to the ink ejection port. It effectively prevents ink ejection failure caused by a decline in the water-repellent function often provided by ejection ports, and also produces streak-free printed matter even when the distance between the fabric surface and the inkjet head is long. In manufacturing, the lower limit of the distance is preferably 3 mm or more, and the upper limit of the distance is preferably 10 mm or less, particularly preferably 5 mm or less.

In the shortest distance, the lower limit of the size of the ink droplet ejected from the ink circulation type inkjet head is preferably 10 pl, more preferably 15 pl, and still more preferably 20 pl, and the upper limit is preferably 50 pl, More preferably, the amount is 45 pl, and even more preferably 40 pl, in order to produce printed matter with excellent image quality without streaks and the like, and to obtain printed matter with even better washing resistance.

Hereinafter, the present invention will be explained in more detail with reference to Examples.

<Synthesis example of dispersion resin (P-1)>
A hexane solution of BuLi and a styrene solution prepared by dissolving styrene in tetrahydrofuran in advance were introduced into a T-shaped micromixer M1 from tube reactors P1 and P2 shown in FIG. 1, and living anion polymerization was performed to obtain a polymer.

Next, the polymer obtained in the above step was transferred to the T-shaped micromixer M2 through the tube reactor R1 shown in FIG. methylstyrene (α-MeSt)).

Next, a tert-butyl methacrylate solution in which tert-butyl methacrylate was previously dissolved in tetrahydrofuran was introduced into the T-shaped micromixer M3 from the tube reactor P4 shown in FIG. , a continuous living anionic polymerization reaction was performed. Thereafter, the living anionic polymerization reaction was quenched by supplying methanol to produce a block copolymer (PA-1) composition.

When producing the block copolymer (PA-1) composition, the reaction temperature was set at 24° C. by immersing the entire microreactor shown in FIG. 1 in a constant temperature bath.

The molar ratio of monomers constituting the block copolymer (PA-1) obtained by the above method is:
(BuLi/styrene/α-methylstyrene/tert-butyl methacrylate)=1.0/12.0/1.3/8.1.

The obtained block copolymer (PA-1) composition was hydrolyzed by treatment with a cation exchange resin and then distilled off under reduced pressure, and the obtained solid was pulverized to have a weight average molecular weight of 2710. A powdery dispersion resin (P-1) having an acid value of 145 was obtained.

Various physical property values of the obtained dispersion resin (P-1) and the polyurethane described below were measured as follows.

(Method for measuring weight average molecular weight (Mw))
It was measured by gel permeation chromatography (GPC) under the following conditions.

Measuring device: High-speed GPC device (“HLC-8220GPC” manufactured by Tosoh Corporation)
Column: The following columns manufactured by Tosoh Corporation were used by connecting them in series.

"TSKgel G5000" (7.8mm I.D. x 30cm) x 1 "TSKgel G4000" (7.8mm I.D. x 30cm) x 1 "TSKgel G3000" (7.8mm I.D. x 30cm) x 1 Book "TSKgel G2000" (7.8mm I.D. x 30cm) x 1 Detector: RI (differential refractometer)
Column temperature: 40℃
Eluent: Tetrahydrofuran (THF)
Flow rate: 1.0 mL/min Injection volume: 100 μL (THF solution with sample concentration 0.4% by mass)
Standard sample: A calibration curve was created using the following standard polystyrene.

(Standard polystyrene)
"TSKgel standard polystyrene A-500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-1000" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-2500" manufactured by Tosoh Corporation
"TSKgel standard polystyrene A-5000" manufactured by Tosoh Corporation
“TSKgel Standard Polystyrene F-1” manufactured by Tosoh Corporation
"TSKgel Standard Polystyrene F-2" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-4" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-10" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-20" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-40" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-80" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-128" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-288" manufactured by Tosoh Corporation
"TSKgel standard polystyrene F-550" manufactured by Tosoh Corporation

(Method of measuring acid value)
Measured according to JIS test method K 0070-1992. It was determined by dissolving 0.5 g of a sample in THF and titrating it with a 0.1M potassium hydroxide alcohol solution using phenolphthalein as an indicator.

<Manufacturing Example 1> Method for manufacturing aqueous pigment dispersion (A1) 150 parts by mass of Fastogen Blue SBG-SD (manufactured by DIC Corporation, CI Pigment Blue 15) as a pigment, 30 parts by mass of the dispersion resin (P-1) Parts by mass, 105 parts by mass of triethylene glycol, and 12.8 parts by mass of a 34% by mass potassium hydroxide aqueous solution were charged into a 1.0 L intensive mixer (Nippon Eirich Co., Ltd.), and the rotor circumferential speed was 2.94 m/s, and the pan was heated. The mixture was kneaded for 60 minutes at a circumferential speed of 1 m/s.

Next, 450 parts by mass of ion-exchanged water was gradually added to the kneaded material in the intensive mixer container while stirring was continued, and then 208.5 parts by mass of ion-exchanged water was further added and mixed to achieve a pigment concentration of 15. A 0% by mass aqueous pigment dispersion (1) was obtained.

<Method for producing urethane resin composition PUD-A1>
500 parts by mass of polycarbonate polyol (number average molecular weight 2000) obtained by reacting 1,6-hexanediol and methyl carbonate in a nitrogen-substituted container equipped with a thermometer, nitrogen gas inlet tube, and stirrer, 2 , 37.7 parts by mass of 2-dimethylolpropionic acid and 420 parts by mass of methyl ethyl ketone were added and mixed uniformly. Next, 140.8 parts by mass of isophorone diisocyanate was added, followed by 0.1 part by mass of dibutyltin dilaurate, and the mixture was reacted at 80°C for 7 hours to form a polyurethane with a weight average molecular weight of 40,000 (acid value: 35 mgKOH/g). An organic solvent solution was obtained. Then, by cooling to 50 ° C., adding 29.8 parts by mass of triethylamine and 2069 parts by mass of water, removing methyl ethyl ketone under reduced pressure at a temperature of 40 ° C. to 60 ° C., and adjusting the concentration by adding water. A urethane resin composition PUD-A1 having a nonvolatile content of 23% by mass was obtained in which the polyurethane was dispersed in an aqueous medium.

<Method for producing urethane resin composition PUD-A2>
500 parts by mass of polycarbonate polyol (number average molecular weight 2000) obtained by reacting 1,6-hexanediol and methyl carbonate in a nitrogen-substituted container equipped with a thermometer, nitrogen gas inlet tube, and stirrer, 2 , 36.5 parts by mass of 2-dimethylolpropionic acid and 436 parts by mass of methyl ethyl ketone were added, and 183.5 parts by mass of dicyclohexylmethane diisocyanate were used, and the reaction was carried out at 80°C for 3 hours to produce a urethane having an isocyanate group at the end of the molecule. A methyl ethyl ketone solution of the prepolymer was obtained. 41.3 parts by mass of triethylamine was added to the methyl ethyl ketone solution of the urethane prepolymer obtained above to neutralize the carboxyl groups in the urethane prepolymer, and then 1504 parts by mass of water was added. Next, 5.2 parts by mass of hydrazine was added and reacted. After the reaction is completed, methyl ethyl ketone is removed under reduced pressure at a temperature of 40°C to 60°C, and water is added to adjust the concentration, whereby the urethane resin is dispersed in an aqueous medium with a nonvolatile content of 23% by mass. A urethane resin composition PUD-A2 containing polyurethane having an average molecular weight of 150,000 and an acid value of 23 mgKOH/g was obtained.

<Method for producing urethane resin composition PUD-B1>
In a nitrogen-substituted container equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 500 parts by mass of polyoxytetramethylene glycol (number average molecular weight 1000), 28.2 parts by mass of 2,2-dimethylolpropionic acid, and By adding 436 parts by mass of methyl ethyl ketone and using 133.8 parts by mass of isophorone diisocyanate and reacting at 80° C. for 3 hours, a methyl ethyl ketone solution of a urethane prepolymer having an isocyanate group at the molecular end was obtained. 14.3 parts by mass of a 25% ammonia aqueous solution was added to the methyl ethyl ketone solution of the urethane prepolymer obtained above to neutralize the carboxyl groups in the urethane prepolymer, and then 1504 parts by mass of water was added. Next, 1.1 parts by mass of hydrazine was added and reacted. After the reaction is completed, methyl ethyl ketone is removed under reduced pressure at a temperature of 40°C to 60°C, and water is added to adjust the concentration, whereby the urethane resin is dispersed in an aqueous medium with a nonvolatile content of 23% by mass. A urethane resin composition PUD-B1 containing polyurethane having an average molecular weight of 39,000 and an acid value of 7 mgKOH/g was obtained.

<Production method of urethane resin composition PUD-B2>
In a nitrogen-substituted container equipped with a thermometer, a nitrogen gas inlet tube, and a stirrer, 500 parts by mass of polyoxytetramethylene glycol (number average molecular weight 2000), 122.7 parts by mass of 2,2-dimethylolpropionic acid, and 420 parts by mass of methyl ethyl ketone was added and mixed uniformly. Next, 280.0 parts by mass of isophorone diisocyanate was added, followed by 0.1 part by mass of dibutyltin dilaurate, and the mixture was reacted at 80°C for 7 hours to form a polyurethane with a weight average molecular weight of 38,000 (acid value: 55 mgKOH/g). An organic solvent solution was obtained. Thereafter, it was cooled to 50°C, 122.9 parts by mass of a 40% by mass aqueous potassium hydroxide solution and 2,069 parts by mass of water were added, methyl ethyl ketone was removed under reduced pressure at a temperature of 40°C to 60°C, and water was added to reduce the concentration. By making adjustments, a urethane resin composition PUD-B2 with a nonvolatile content of 23% by mass, in which the polyurethane was dispersed in an aqueous medium, was obtained.

<Example 1> Preparation of water-based ink and printed matter 29.3 parts by mass of the aqueous pigment dispersion (1), 18.3 parts by mass of urethane resin composition PUD-A1 (nonvolatile content 23% by mass) as polyurethane (A), As polyurethane (B), 12.2 parts by mass of urethane resin composition PUD-B1 (nonvolatile content 23% by mass), 1 part by mass of Surfynol 440 (manufactured by EVONIK, acetylene surfactant), 25.0 parts by mass of glycerin, A water-based ink was obtained by mixing 5.0 parts by mass of propylene glycol, 0.05 parts by mass of ACTICIDE B-20 (manufactured by So Japan Co., Ltd.) as a preservative, and 9.15 parts by mass of ion exchange water. The aqueous ink had a viscosity of 10 mPa·s and a surface tension of 33 mN/m at 25°C.

An ink circulation type inkjet head having an ink discharge nozzle, an ink inflow path, and an ink outflow path, the ink flowing out from the outflow path being supplied to the inkjet head via the inflow path. A printing device was filled with the aqueous ink obtained above.

Next, the distance (gap) from the surface (x) having the ink ejection ports of the ink circulation type inkjet head to the position (y) where the perpendicular line assumed to the surface (x) intersects with the fabric is 3 mm. It was set to Cotton broadcloth (manufactured by Irosensha Co., Ltd.) was used as the fabric.

After wiping the nozzle surface of the ink circulation type inkjet head, a 100% solid image was printed on the fabric at a driving frequency of 10 kHz, then dried at 100°C for 1 minute, and then at 150°C for 5 minutes. A printed matter was obtained by performing the heat treatment.

The viscosity and static surface tension of the aqueous ink were measured by the following methods.

The viscosity of the ink was measured using a cone-plate rotational viscometer equivalent to an E-type viscometer under the following conditions.
Measuring device: TVE-25 type viscometer (manufactured by TVE-25 L)
Calibration standard solution: JS20
Measurement temperature: 25℃
Rotation speed: 10-100rpm
Injection volume: 1200μL
The static surface tension of the ink was measured using an automatic surface tension meter applying the Wilhelmi method under the following conditions.
Measuring device: Automatic surface tension meter (manufactured by Kyowa Interface Science Co., Ltd., CBVP-Z type)
Measurement temperature: 25℃
Measuring element: platinum plate

<Examples and Comparative Examples> Preparation of water-based ink A water-based ink was prepared in the same manner as in Example 1, except that the formulation of the water-based ink was changed to Tables 1 and 2 below, and printed matter was obtained.

[Evaluation of circulation filtration characteristics (difficulty in clogging of the filter installed in the middle of the ink circulation path)]
The above-mentioned circulation filtration characteristics were determined by circulating 200 g of the aqueous inks obtained in the examples and comparative examples in a circulation device having a circulation path equipped with a SUS mesh filter (manufactured by Manabe Industries Co., Ltd.) with a pore size of 12 μm. evaluated. The flow rate of the aqueous ink immediately after the start of the circulation was adjusted to 50 g/min.

The flow rate of the aqueous ink was measured every hour from the start of the circulation, and the circulation filtration performance was evaluated based on the elapsed time when the flow rate became 25 g/min or less and the following evaluation criteria.

A: 168 hours from the start of circulation B: 120 hours or more and less than 168 hours from the start of circulation C: 72 hours or more and less than 120 hours from the start of circulation D: 24 hours or more and less than 72 hours from the start of circulation E: Less than 24 hours from the start of circulation

[Evaluation of washing fastness]
The washing fastness of the printed matter obtained by the above method was tested in accordance with method A-2 of JIS L 0844:2005, and then visually evaluated using the gray scale for discoloration and fading of JIS L 0801:2004. The grades were determined from 1st grade to 5th grade according to the criteria of the law. Note that the grades indicate that 1st grade shows the greatest discoloration, and the closer to 5th grade, the less discoloration.

・○: Level 4 or higher ・△: Level 3 or higher but lower than level 4 ・×: Lower than level 3

[Evaluation of viscosity stability]
The viscosity V ₀ of the aqueous ink immediately after production was measured by the method described above. Next, 20 mL of the aqueous ink was sealed in a glass container and allowed to stand for 4 weeks in an environment of 60° C., and then the viscosity V ₁ was measured in the same manner as above. The rate of change in viscosity was calculated based on the measurement results and the formula [(V1-V0)/V0]×100, and evaluated based on the following criteria.

・○: The rate of change in viscosity is less than ±5% ・△: The rate of change in viscosity is ±5% or more and less than ±10% ・×: The rate of change in viscosity is ±10% or more

[Evaluation of ink resolubility]
A printed matter was obtained by applying 1 mL of the water-based ink onto a SUS substrate and heating it on a 40° C. hot plate for 5 minutes. The printed material was immersed in 20 mL of pure water, and after 1 minute, the printed surface of the printed material was visually observed and evaluated using the following criteria.

○: No coloring △: A thin colored film remains ×: A dark colored film remains

1: T-shaped micro mixer M1
2: T-shaped micro mixer M2
3: T-shaped micro mixer M3
4: Tube reactor R1
5: Tube reactor R2
6: Tube reactor R3
7: Tube reactor P1 for pre-cooling
8: Tube reactor P2 for pre-cooling
9: Tube reactor P3 for pre-cooling
10: Tube reactor P4 for pre-cooling

Claims (7)

A method for producing a printed matter, comprising a printing step of obtaining a printed matter by printing ink on a fabric using a printing device equipped with an ink circulation type inkjet head, the method comprising:
In the printing step, the shortest distance between the ink ejection opening of the ink circulation type inkjet head and the fabric is 2 mm or more,
The size of one ink droplet ejected from the ink circulation type inkjet head is in the range of 10 to 50 pl,
The ink is characterized in that the ink contains a polyurethane (A) having a carbonate structure, a polyurethane (B) having an ether structure, and a solvent (C),
The weight average molecular weight of the polyurethane (A) is in the range of 40,000 to 200,000,
The weight average molecular weight of the polyurethane (B) is in the range of 10,000 to 39,000,
Furthermore, it contains a surfactant,
A method for producing printed matter, characterized in that the surfactant is an ink containing an acetylene surfactant. The method for producing printed matter according to claim 1, wherein the mass ratio of the polyurethane (A) and the polyurethane (B) [the polyurethane (A)/the polyurethane (B)] is in the range of 1.5 to 9. The method for producing printed matter according to claim 1 or 2, wherein the content of the surfactant is in the range of 0.001% by mass to 2% by mass based on the total amount of the ink. According to any one of claims 1 to 3, the polyurethane (A) is a polyurethane having a weight average molecular weight of 40,000 to 50,000 and having no urea bond, or a polyurethane having a weight average molecular weight of 70,000 to 170,000 and having a urea bond. A method of producing printed matter . The method for producing printed matter according to any one of claims 1 to 4, wherein the ink circulation type inkjet head is provided with a filter having a pore diameter in the range of 5 μm to 20 μm in its circulation path. Production of a printed matter according to any one of claims 1 to 5, wherein the ratio of the total mass of the polyurethane (A) and the polyurethane (B) to the total amount of the ink is in the range of 5% by mass to 15% by mass. Method . The ink circulation type inkjet head has an ink discharge nozzle, an ink inflow path, and an ink outflow path,
7. The method for producing a printed matter according to claim 1 , wherein the ink discharged from the outflow path is supplied to an inkjet head via the inflow path.

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