JP2010023265A - Inkjet recording method and recorded matter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inkjet recording method of printing using a reaction liquid and an ink composition on a recording medium with low absorptivity, wherein a recorded image having scratch resistance and no printing irregularity is provided. <P>SOLUTION: This invention relates to the inkjet recording method of printing by depositing the reaction liquid and the ink composition on the recording medium, wherein the recording medium has an absorbing layer of a paper supporting body wherein an water absorption amount within 30 msec<SP>1/2</SP>from the start of contact in the Bristow method is ≤30 ml/m<SP>2</SP>, and the reaction liquid contains a polyvalent metallic salt, at least one selected from polyallyl amine and a polyallyl amine derivative, a cationic polyurethane and a polyether modified polysiloxane based compound, and the ink composition contains water, a coloring agent and a resin emulsion particle. The recorded matter obtained by the inkjet recording method is also provided. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an inkjet recording method and a recorded matter. More specifically, the present invention relates to an ink jet recording method using two liquids for printing by attaching a reaction liquid and an ink composition to a recording medium having a low water-absorbing paper support absorption layer, and a recorded matter thereof.

  The ink jet recording method is a printing method in which printing is performed by ejecting ink droplets from a printer head and landing on a recording medium such as paper. This printing method is easy to reduce in size, speed up, reduce noise, save power, and color, and is capable of non-contact printing on a recording medium. It is used for various purposes.

  Especially for industrial use, it is possible to obtain images that are close to multicolor printing by the plate making method and silver salt photography method for images formed by the full color ink jet recording method, and when printing a small number of various types of copies. In some cases, it is cheaper than normal multicolor printing, and its use has expanded in recent years.

  An ink composition usually used for ink jet recording is generally a water-based ink composition having a low viscosity and a high water content, which contains water as a main component and contains a coloring component and a clogging-preventing wetting agent. Therefore, a highly water-absorbing inkjet special paper is usually used for the recording medium.

  Highly water-absorbing inkjet paper has an absorbent layer on the paper surface made of fine powdered silica, alumina, etc., and even when recording an ink composition with a high water content using this absorbent layer, Can be absorbed, and good print quality without bleeding or color bleeding can be realized. However, since high-priced fine powdered silica, alumina, or the like is used, it has become a barrier that narrows the application for industrial printing users who want to realize further cost reduction of printed matter.

  On the other hand, as an inexpensive medium, there is a coated paper (also referred to as a coated paper for printing, a coated paper for printing, or a printing paper) as a low water-absorbing recording medium. Coated paper is a composite sheet in which a coating color, which is a kind of paint, is applied to both sides or one side of a base paper for the purpose of improving printability, and is exclusively used for printing paper. The coated paper is used in a recording method using a high-viscosity ink composition (low water-containing ink), a solvent-based ink composition, or the like. Coated paper is supported by vigorous demand of several million tons per year, mass production facilities are in place, and high-quality coated paper is supplied at an extremely low cost.

  However, an ink composition having a high viscosity and a low water content can realize good image quality even on a recording medium having low water absorption or non-absorption, but it has reliability such as clogging recovery and ejection stability. The technical hurdles for securing the safety are increased, and the printing apparatus and printing method are limited as the ink jet recording method. In addition, solvent-based ink compositions are composed of raw materials that are sparingly soluble or insoluble in water (for example, lipophilic organic solvents such as toluene), so they have excellent image quality, abrasion resistance, durability, and quick drying of ink. However, certain organic solvents may be toxic to animals and plants, or may have a significant impact on health hazards to workers due to air pollution caused by highly volatile organic solvents (VOC). In some cases, it is inconvenient in terms of safety and environment.

  On the other hand, a low-viscosity water-based ink composition used in general ink jet recording is easy to ensure safety and environmental properties, and ejection reliability as an ink jet recording method, but has a thick absorption layer such as ink jet dedicated paper. For recording on recording media such as coated paper that are not provided, the water absorption is extremely poor, which may cause deterioration of image quality such as bleeding, color bleed, printing unevenness, abrasion resistance, quick drying, etc. Therefore, it was considered to be unsuitable as a recording medium.

  On the other hand, as an ink jet recording method, recently, a method has been proposed in which a polyvalent metal salt solution is applied to a recording medium, and then an ink composition containing a dye having at least one carboxyl group is applied (Patent Document 1). ). In this method, an insoluble complex is formed from a polyvalent metal ion and a dye, and the presence of this complex is said to provide a high-quality image having water resistance and no color bleeding.

  Further, by using a combination of a color ink containing at least a surfactant or a penetrating solvent that imparts penetrability and a salt and a black ink that thickens or aggregates due to the action of this salt, the image density is increased. There has also been a proposal that a high-quality color image without color bleeding can be obtained (Patent Document 2). That is, an ink jet recording method has been proposed in which a good image can be obtained by printing two liquids of a first liquid containing salt and an ink composition.

  In addition, inkjet recording methods for printing two liquids have been proposed (Patent Documents 3 to 7).

  Here, in the ink jet recording method for printing two liquids on a low water-absorbing recording medium (coated paper or the like), the following points are mentioned as required characteristics.

1) The reaction solution can be uniformly applied to a low water-absorbing recording medium such as coated paper.
2) Reaction liquid and ink composition react to prevent bleeding, color bleeding, and printing unevenness.
3) Excellent rub resistance of recorded matter (excellent adhesion and adhesion to the recording medium).
4) It should be easy to dry after application to the recording medium.
5) The properties of the reaction liquid and the ink composition do not deteriorate over time (excellent storage stability).
6) The reaction liquid and the ink composition can be ejected by inkjet, and the head is not clogged in actual use.
However, in the prior art, an ink jet recording method that satisfies all the above characteristics has not been obtained. In particular, when the uniform wettability of the reaction liquid with respect to the recording medium is low, there is a problem that so-called uneven printing is likely to occur, which causes the concentration distribution of the coloring component of the ink composition to be printed thereafter. In addition, if the wettability of the reaction liquid is not uniform, the reaction liquid and the agglomerated reaction product of the ink composition will have a non-uniform distribution, and the formed resin film will also have irregularities, which will increase the resistance during rubbing. Thus, there is a problem that the abrasion resistance is likely to deteriorate.

JP-A-5-202328 JP-A-6-106735 JP-A-3-240557 JP-A-3-240558 JP-A-9-207424 JP-A-10-195404 JP 2001-315425 A

  As described above, the advantages of the ink jet recording method that is simple and small, the recording medium such as coated paper (low-water-absorbing recording medium) that is inexpensive and has excellent printability, and the highly safe aqueous ink composition Combining things has long been awaited in the industry, but there is still room for improvement.

  Therefore, the present invention is capable of ink jet ejection and has a high-quality recorded image free from bleeding, color bleeding, printing unevenness, and the like on a recording medium having a low water-absorbent paper support absorption layer, and abrasion resistance. It is another object of the present invention to provide an ink jet recording method for printing two liquids and a recorded matter using a reaction liquid having excellent recording characteristics and excellent storage stability, ejection stability, and clogging recovery.

As a result of earnest research, the inventor of the present invention is an ink jet recording method in which a reaction liquid and an ink composition are attached to a recording medium to perform printing, and the recording medium is 30 msec ^{1 / And} having a water-absorbing layer of a paper support having a water absorption amount of ² or less of ² or less, and the reaction solution is at least one selected from polyvalent metal salts, polyallylamine and polyallylamine derivatives A cationic polyurethane and a polyether-modified polysiloxane compound, and the ink composition comprises water, a colorant, and resin emulsion particles. The present inventors have found that an ink jet recording method can achieve the above object, and have reached the present invention.

  That is, the present invention has the following configuration.

(1) An ink jet recording method for printing by attaching a reaction liquid and an ink composition to a recording medium, wherein the recording medium has a water absorption amount within 30 msec ^1/2 from the start of contact in the Bristow method. A paper support that has an absorption layer of 30 ml / m ² or less, and the reaction solution is at least one selected from a polyvalent metal salt, a polyallylamine, and a polyallylamine derivative, a cationic polyurethane, An ink jet recording method comprising: a polyether-modified polysiloxane compound; and the ink composition comprising water, a colorant, and resin emulsion particles.

  (2) The inkjet recording method according to (1), wherein the polyvalent metal salt is at least one selected from sulfates, nitrates, and carboxylates.

  (3) The inkjet recording method according to (1) or (2), wherein the polyether-modified polysiloxane compound is a polyether-modified polysiloxane compound represented by a general formula of the following formula (1).

  (4) The inkjet recording method according to any one of (1) to (3), wherein the reaction solution further includes a long-chain alkyl glycol ether.

  (5) The inkjet recording method according to (4), wherein the content of the long-chain alkyl glycol ether in the reaction solution is 10% by weight or less.

  (6) The inkjet recording method according to any one of (1) to (5), wherein the reaction solution further contains diacetylenetetraol represented by the general formula of the following formula (2).

  (7) The inkjet recording method according to any one of (1) to (6), wherein the reaction solution further includes 1,2-alkanediol.

  (8) The reaction solution further comprises a polyhydric alcohol and / or saccharide as a wetting agent, and the content of the polyhydric alcohol and / or saccharide in the reaction solution is 0.1 wt% to 10 wt%. The inkjet recording method according to any one of (1) to (7).

  (9) The inkjet recording method according to any one of (1) to (8), wherein the colorant of the ink composition is a pigment.

  (10) The method according to any one of (1) to (9), including a step of heating the recording medium to which the reaction liquid and / or the ink composition is attached at 40 ° C. to 150 ° C. Inkjet recording method.

  (11) A recorded matter recorded by the inkjet recording method according to any one of (1) to (10).

  According to the present invention, a high-quality recorded image free from bleeding, color bleed, printing unevenness, and the like, and rub resistance against a recording medium having an absorbent layer of a paper support that is capable of inkjet ejection and having a low water absorption. In addition, it is possible to provide an ink jet recording method for printing two liquids and a recorded matter using a reaction liquid having excellent recording characteristics and excellent storage stability, ejection stability, and clogging recovery ability.

  Hereinafter, the present invention will be described in more detail based on preferred embodiments thereof.

The ink jet recording method of the present embodiment is an ink jet recording method in which a reaction liquid and an ink composition are attached to a recording medium to perform printing, and the recording medium is 30 msec ^1/2 from the start of contact in the Bristow method. And having a water-absorbing layer of a paper support having a water absorption amount of 30 ml / m ² or less, and the reaction solution is at least one selected from polyvalent metal salts, polyallylamine and polyallylamine derivatives , A cationic polyurethane and a polyether-modified polysiloxane compound, and the ink composition comprises water, a colorant, and resin emulsion particles. .

[recoding media]
The inkjet recording method of the present embodiment is useful when applied to a recording medium having a low water-absorbing paper support absorbing layer as a recording medium.

In the present embodiment, the “recording medium having a low water-absorbing paper support absorbing layer” means a paper support having a water absorption of 30 ml / m ² or less within 30 msec ^1/2 from the start of contact in the Bristow method. A recording medium having an absorption layer. In this embodiment, any coated paper (printing coating) conventionally used as printing paper for letterpress printing, flat printing (for example, offset printing), or intaglio printing (for example, gravure printing). Paper, coated paper for printing, and printing paper). This coated paper includes ordinary coated paper, cast coated paper, and matte coated paper. Also included are printing original paper defined by JISP0001 number 6122, OK topcoat paper defined by JISP0001 number 6059, and the like.

  The Bristow method is the most popular method for measuring the amount of liquid absorbed in a short time, and is also adopted by the Japan Paper Pulp Technology Association (J'TAPPI). Details of the test method are described in J'TAPPI No. 51, “Method for testing liquid absorbency of paper and paperboard”.

[Reaction solution]
The reaction liquid in the present invention comprises at least one selected from a polyvalent metal salt, polyallylamine and a polyallylamine derivative, a cationic polyurethane, and a polyether-modified polysiloxane compound. This “polyvalent metal salt, polyallylamine and polyallylamine derivative” has a function as a reactive agent, destroys the dispersion and / or dissolution state of the colorant, resin emulsion particles, etc. in the ink composition, and aggregates. It can be made.

[Multivalent metal salt]
The polyvalent metal salt that can be used in the reaction solution is composed of a divalent or higher polyvalent metal ion and an anion that binds to the polyvalent metal ion, and is soluble in water. Specific examples of the polyvalent metal ions include divalent metal ions such as Ca ²⁺ , Cu ²⁺ , Ni ²⁺ , Mg ²⁺ , Zn ²⁺ , and Ba ²⁺ , Al ³⁺ , Fe ³⁺ , and Cr ^{3. And} trivalent metal ions such as ⁺ . Examples of the anion include Cl ⁻ , NO ³⁻ , I ⁻ , Br ⁻ , ClO ³⁻ , and CH ₃ COO ⁻ .

In particular, a metal salt composed of Ca ²⁺ or Mg ²⁺ gives favorable results from the two viewpoints of the pH of the reaction solution and the quality of the obtained printed matter.

  The content of these polyvalent metal salts in the reaction solution may be appropriately determined within the range in which the printing quality and the effect of preventing clogging can be obtained, but is preferably about 0.1 wt% to 40 wt%, more preferably Is about 2 wt% to 25 wt%.

  According to a preferred embodiment of the present invention, the polyvalent metal salt contained in the reaction solution is composed of a divalent or higher polyvalent metal ion and a sulfate ion, nitrate ion or carboxylate ion that binds to the polyvalent metal ion. Is done.

  Here, the carboxylate ion is preferably derived from a saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms or a carbocyclic monocarboxylic acid having 7 to 11 carbon atoms. Preferable examples of the saturated aliphatic monocarboxylic acid having 1 to 6 carbon atoms include formic acid, acetic acid, propionic acid, butyric acid, isobutyric acid, valeric acid, isovaleric acid, pivalic acid, hexanoic acid and the like. In particular, formic acid and acetic acid are preferred.

  The hydrogen atom on the saturated aliphatic hydrocarbon group of this monocarboxylic acid may be substituted with a hydroxyl group, and a preferred example of such a carboxylic acid is lactic acid.

  Furthermore, preferable examples of the carbocyclic monocarboxylic acid having 6 to 10 carbon atoms include benzoic acid and naphthoic acid, and benzoic acid is more preferable.

[Polyallylamine and polyallylamine derivatives]
The polyallylamine and polyallylamine derivatives that can be used in the reaction solution are cationic polymers that are soluble in water and positively charged in water.

  The polyallylamine and / or polyallylamine derivative used in the reaction solution of the present invention is not particularly limited, and can be appropriately selected from known ones such as polyallylamine hydrochloride and polyallylamine amide sulfate. , Allylamine hydrochloride / diallylamine hydrochloride copolymer, allylamine acetate / diallylamine acetate copolymer, allylamine acetate / diallylamine acetate copolymer, allylamine hydrochloride / dimethylallylamine hydrochloride copolymer, allylamine / dimethylallylamine copolymer, polydiallylamine hydrochloride, poly Methyldiallylamine hydrochloride, polymethyldiallylamine amide sulfate, polymethyldiallylamine acetate, polydiallyldimethylammonium chloride, diallylamine acetate / sulfur dioxide Copolymers, diallyl methyl ethyl ammonium ethyl sulfates, sulfur dioxide copolymer, methyl diallyl amine hydrochloride-sulfur dioxide copolymers, diallyldimethylammonium chloride-sulfur dioxide copolymers, diallyldimethylammonium chloride-acrylamide copolymer and the like.

  As such polyallylamine and / or polyallylamine derivatives, commercially available products can be used. For example, “PAA-HCL-01”, “PAA-HCL-03”, “PAA-HCL-05”, “ "PAA-HCL-3L", "PAA-HCL-10L", "PAA-H-HCL", "PAA-SA", "PAA-01", "PAA-03", "PAA-05", "PAA- 08 "," PAA-15 "," PAA-15C "," PAA-25 "," PAA-H-10C "," PAA-D11-HCL "," PAA-D41-HCL "," PAA-D19- HCL "," PAS-21CL "," PAS-M-1L "," PAS-M-1 "," PAS-22SA "," PAS-M-1A "," PAS-H-1L "," PAS- H-5L ", "PAS-H-10L", "PAS-92", "PAS-92A", "PAS-J-81L", "PAS-J-81" (trade name, manufactured by Nitto Boseki Co., Ltd.), "Himo Neo-600 ”,“ Himolock Q-101 ”,“ Himoloc Q-311 ”,“ Himolock Q-501 ”,“ Himax SC-505 ”,“ Himax SC-505 ”(trade name, manufactured by Hymo Corporation), etc. be able to.

  The content of the polyallylamine and the polyallylamine derivative in the reaction solution is preferably 0.5% by weight to 10% by weight from the viewpoint of printing quality and the effect of preventing clogging.

[Cationic polyurethane]
The reaction solution of the present invention comprises cationic polyurethane. By using a reaction liquid containing a cationic polyurethane, an agglomerated reaction product containing a coloring component can be more firmly adhered and adhered to a recording medium, and excellent abrasion resistance can be realized.

  The cationic polyurethane used in the reaction solution of the present invention is not particularly limited, and known ones can be appropriately selected and used.

  Examples thereof include cationic polyurethanes obtained by the following preparations (1) to (2) and the like, and in particular, a composition in which cationic polyurethane is dispersed in water, that is, an aqueous dispersion is preferable.

  The preparation of the cationic polyurethane comprises (1) using a polyester polyol (B1) as a polyol for urethane reaction with the polyisocyanate (A), and using a chain extender (C) having a tertiary amino group to convert a urethane prepolymer. A cationic polyurethane composition is prepared by neutralizing part of this tertiary amino group with an acid or quaternizing with a quaternizing agent to make the amine value in the range of 1 to 40 (KOHmg / g). Can be obtained. (2) Polycarbonate polyol (B2), chain extender (C) having a tertiary amino group, and polyalkylene oxide (D) containing 50% by mass or more of an ethylene oxide chain, the polyisocyanate (A) A cationic polyurethane can be obtained by preparing a urethane prepolymer using, and neutralizing a tertiary amino group introduced by the chain extender (C) with an acid or quaternizing with a quaternizing agent. . By obtaining this cationic polyurethane in a form dispersed in water, it can be obtained as an aqueous dispersion.

  Hereinafter, the preparation (1) will be described.

  As the polyisocyanate (A), conventionally used polyisocyanates such as aliphatic, alicyclic, aromatic, and araliphatic can be used.

  Specific examples of the aliphatic polyisocyanate include tetramethylene diisocyanate, dodecamethylene diisocyanate, 1,4-butane diisocyanate, hexamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, 2,4,4-trimethylhexamethylene diisocyanate, Examples include lysine diisocyanate, 2-methylpentane-1,5-diisocyanate, and 3-methylpentane-1,5-diisocyanate.

  Specific examples of the alicyclic polyisocyanate include isophorone diisocyanate, hydrogenated xylylene diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, methylcyclohexylene diisocyanate, 1,3-bis (isocyanate methyl). A cyclohexane etc. can be mentioned.

  Specific examples of the aromatic polyisocyanate include tolylene diisocyanate, 2,2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-diphenyldimethylmethane diisocyanate, 4, Examples include 4′-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, xylylene diisocyanate, 1,3-phenylene diisocyanate, 1,4-phenylene diisocyanate, and the like.

  Specific examples of the araliphatic polyisocyanate include dialkyldiphenylmethane diisocyanate, tetraalkyldiphenylmethane diisocyanate, α, α, α, α-tetramethylxylylene diisocyanate and the like.

  These polyisocyanates may be used alone or in a combination of two or more.

  As the polyester polyol (B1), those composed of various polycarboxylic acids and polyols can be used, but depending on the dicarboxylic acid composed of an aliphatic dibasic acid and an aromatic dibasic acid, and an aliphatic glycol. What is comprised is more preferable at the point that adhesiveness becomes high. Examples of the aliphatic dibasic acid include malonic acid, succinic acid, tartaric acid, succinic acid, glutaric acid, adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, alkyl succinic acid, linolenic acid, maleic acid, fumaric acid , Mesaconic acid, citraconic acid, itaconic acid, glutaconic acid and the like, or reactive derivatives such as acid anhydrides, alkyl esters, acid halides, and the like. These aliphatic dicarboxylic acids can be used alone or in combination of two or more. Examples of the aromatic dibasic acid include phthalic acid, isophthalic acid, terephthalic acid, 1,4-naphthalenedicarboxylic acid, 2,5-naphthalenedicarboxylic acid, 2,6-naphthalenedicarboxylic acid, biphenyldicarboxylic acid, tetrahydro Examples thereof include phthalic acid and the like, or reactive derivatives thereof such as acid anhydrides, alkyl esters, and acid halides. These aromatic dicarboxylic acids can be used alone or in combination of two or more.

  Examples of the aliphatic glycol include ethylene glycol, diethylene glycol, triethylene glycol, 1,3-propanediol, 1,3-butanediol, 1,4-butanediol, neopentyl glycol, pentanediol, 1,6-hexanediol, A propylene glycol etc. can be illustrated and these can be used individually or in combination of 2 or more types.

  The chain extender (C) having a tertiary amino group in the molecule is used for introducing the tertiary amino group into the urethane prepolymer. Examples of such chain extenders (C) include N-alkyldialkanolamines such as N-methyldiethanolamine and N-ethyldiethanolamine, N-alkyldiaminoalkylamines such as N-methyldiaminoethylamine and N-ethyldiaminoethylamine, A triethanolamine etc. can be mentioned. These chain extenders (C) having a tertiary amino group can be used alone or in combination of two or more.

  The addition amount of the chain extender (C) in the preparation (1) is 5% by mass to 20% by mass with respect to the total of the polyisocyanate (A), the polyester polyol (B1), and the chain extender (C). It is more preferable. If the amount of the chain extender (C) added is less than 5% by mass, the number of tertiary amino groups to be introduced decreases, and the tendency for the adhesion and water resistance of the ink to decrease appears. Moreover, when there is more addition amount of chain extender (C) than 20 mass%, it will become difficult to acquire the effect which improves adhesiveness and durability corresponding to addition amount, and chain extender (C) like this. There is a tendency that a urethane prepolymer having an increased amount of added is difficult to prepare.

  In the present invention, the free NCO at the end of the urethane prepolymer produced by the reaction of the polyisocyanate (A), the polyester polyol (B1), and the chain extender (C) having a tertiary amino group in the molecule is contained. The amount is more preferably in the range of 1% by mass to 5% by mass. When the content of this terminal free NCO is less than 1% by mass, it is not preferable because preparation of the urethane prepolymer becomes difficult. Moreover, when there is more content of terminal free NCO than 5 mass%, since the cohesion force of the water-based polyurethane resin obtained becomes high too much, it is unpreferable at the point of adhesiveness.

  In the present invention, a cationic urethane prepolymer in which a tertiary amino group introduced by the chain extender (C) and a part thereof are neutralized with an acid or quaternized with a quaternizing agent is prepared. When the tertiary amino group and a part thereof are neutralized with an acid, the acids include formic acid, acetic acid, propionic acid, butyric acid, lactic acid, malic acid, malonic acid, adipic acid and other organic acids, and hydrochloric acid, phosphoric acid, Mention may be made of inorganic acids such as nitric acid. These acids can be used alone or in combination of two or more.

  In addition, when quaternizing a tertiary amino group and a part thereof with a quaternizing agent, quaternizing agents include alkyl halides such as benzyl chloride and methyl chloride, sulfate esters such as dimethyl sulfate and diethyl sulfate. Etc. These quaternizing agents can be used in combination of two or more in addition to being used alone.

  As described above, the tertiary amino group and a part thereof are not completely neutralized or quaternized, and only a part of the tertiary amino group is neutralized or quaternized. The amount of the tertiary amino group remaining without being neutralized or quaternized is an amount such that the amine value of the cationic polyurethane is 1 to 40 (KOHmg / g). It can be adjusted by quaternization.

  Next, the preparation (2) will be described.

  The polyisocyanate (A) used in the preparation (2) is the same as the polyisocyanate (A) used in the preparation (1) and is as described above.

  As said polycarbonate polyol (B2) used for preparation (2), it is obtained by reaction of glycols, such as 1, 4- butanediol, 1, 6- hexanediol, diethylene glycol, and diphenyl carbonate and phosgene, for example. Compounds and the like. These aromatic dicarboxylic acids can be used alone or in combination of two or more.

  The addition amount of the polycarbonate polyol (B2) is in the range of 40% by mass to 80% by mass with respect to the total of the polyisocyanate (A), the polycarbonate polyol (B2), the chain extender (C), and the polyalkylene oxide (D). It is preferable that If the added amount of the polycarbonate polyol (B2) is less than 40% by mass, the durability of the resulting urethane resin is lowered, and the tendency to be poor in adhesion to a recording medium is not preferable. On the other hand, if it is more than 80% by mass, the cohesive force of the resulting cationic polyurethane becomes insufficient and the durability is also lowered, which is not preferable.

  In this invention, the polyalkylene oxide (D) containing an ethylene oxide chain can be used as a structural component of a polyurethane. This polyalkylene oxide (D) is used to increase the affinity with the ink to be printed. Examples of such polyalkylene oxide (D) include ethylene oxide, a copolymer of ethylene oxide and propylene oxide, and the like. These polyalkylene oxides (D) can be used alone or in combination of two or more. When the content of the ethylene oxide chain in the polyalkylene oxide (D) is less than 50% by mass, the affinity with the ink may be lowered.

  The addition amount of the polyalkylene oxide (D) is 3% by mass to 10% by mass with respect to the total of the polyisocyanate (A), the polycarbonate polyol (B2), the chain extender (C), and the polyalkylene oxide (D). Preferably there is. If the addition amount of the polyalkylene oxide (D) is lower than 3% by mass, the affinity with the ink becomes insufficient, such being undesirable. On the other hand, when the amount of polyalkylene oxide (D) added is more than 10% by mass, the water resistance decreases, which is not preferable.

  In the preparation (2), the chain extender (C) used is the same as in the preparation (1).

  The addition amount of the chain extender (C) used in the preparation (2) is based on the total of the polyisocyanate (A), the polycarbonate polyol (B2), the chain extender (C), and the polyalkylene oxide (D). It is preferable that it is 5 mass%-15 mass%. When the amount of the chain extender (C) added is less than 5% by mass, the tertiary amino groups to be introduced are decreased, and the adhesion tends to be lowered. Moreover, when there is more addition amount of chain extender (C) than 15 mass%, since the effect which improves the adhesiveness corresponding to addition amount will not be acquired, it is unpreferable.

  Acid and quaternizing agent when the tertiary amino group introduced by the chain extender (C) used in the preparation (2) and a part thereof are neutralized with an acid or quaternized with a quaternizing agent Is the same as in the case of the preparation (1).

  In the preparation of the above (1) and (2), the cationic urethane prepolymer obtained by neutralizing or quaternizing the tertiary amino group and a part thereof may be converted to a polyallylamine compound (if necessary) when dispersed in water. It may be prepared using D1). Examples of polyallylamine compounds that can be used include aminodiamines such as ethylenediamine, propylenediamine, diethylenetriamine, hexylenediamine, triethylenetetramine, tetraethylenepentamine, isophoronediamine, piperazine, diphenylmethanediamine, hydrazine, and adipic acid dihydrazide. Mention may be made of compounds having two or more groups.

  In the preparation of (1) and (2), a polyol having 3 or more hydroxyl groups may be further added. When a polyol having 3 or more hydroxyl groups is added, adhesion to the recording medium can be improved. However, it is necessary to use the obtained cationic polyurethane as long as the water dispersibility is not impaired. Examples of such polyols include sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, trimethylol. Ethane, trimethylolpropane, pentaerythritol and the like can be mentioned, and these can be used alone or in combination of two or more.

  In the preparation of the above (1) and (2), the cationic urethane prepolymer obtained by neutralizing or quaternizing the tertiary amino group or part thereof as described above is then dispersed in water, The cationic polyurethane used in the invention and the dispersion thereof are obtained.

  For the cationic polyurethane, the resins described in paragraph numbers [0006] to [0048] of JP-A No. 2002-30781 and paragraph numbers [0006] to [0053] of JP-A No. 2002-307812 are used in detail. Can do.

  As the cationic polyurethane, commercially available products can be used, and as the commercially available products of the cationic polyurethane, “Hydran CP-7010”, “Hydran CP-7020”, “Hydran CP-7030”, “Hydran CP-7040” can be used. "," Hydran CP-7050 "," Hydran CP-7060 "," Hydran CP-7610 "(trade name, manufactured by Dainippon Ink & Chemicals, Inc.)," Superflex 600 "," Superflex 610 "," Super "Flex 620", "Superflex 630", "Superflex 640", "Superflex 650" (trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), "Urethane emulsion WBR-2120C", "Urethane emulsion WBR-2122C" ( Product name, Taisei It can be used § in-Chemical Co., Ltd.), and the like.

  The content of the cationic polyurethane in the reaction solution is preferably 0.5% by weight to 15% by weight, more preferably 1% by weight to 10% by weight, and still more preferably 1% by weight to 6% by weight. .

[Polyether-modified polysiloxane compound]
The reaction solution in the present invention comprises a polyether-modified polysiloxane compound.

  By using a reaction solution containing a polyether-modified polysiloxane compound, it contributes to improving the wettability to the recording medium due to a decrease in the surface tension of the reaction solution, and enables uniform coating. Therefore, since the ink composition printed after the reaction liquid can be printed uniformly, it is possible to suppress printing unevenness and improve abrasion resistance. Furthermore, the polyether-modified polysiloxane compound also acts as a penetrant. Therefore, there is an advantage that an improvement in the drying property of the printed matter can be realized at the same time. Furthermore, the color image has an advantage that it is possible to effectively prevent uneven color mixing, that is, color bleeding in the boundary area of different colors.

  As the polyether-modified polysiloxane compound, the compound represented by the following formula (1) is effective for smoothing and uniforming the unevenness of the coated surface, particularly when applied to a low water-absorbing recording medium such as coated paper. However, it is preferable in that further suppression of printing unevenness and improvement in abrasion resistance can be realized.

As this polyether modified polysiloxane compound, preferably, in the above formula (1), R ^{1 to} R ⁷ are independently an alkyl group having 1 to 6 carbon atoms, preferably a methyl group. j, k and g are each independently an integer of 1 or more, and more preferably 1 or 2. P and q are integers of 0 or more, provided that p + q is an integer of 1 or more, and preferably p + q is 2-4.

Moreover, as a compound represented by the said Formula (1), the compound which satisfies j = k + g is preferable, for example. In the compound represented by the general formula (1), R ^{1 to} R ⁷ are all methyl groups, j is 2, k is 1, g is 1, and p is 1 or more. A compound in which q is 0 is preferable.

  Commercially available products can be used as the compound represented by the above formula (1). For example, BYK-345, BYK-346, BYK-347, BYK-348, UV3530 (trade name, manufactured by Big Chemie Japan Co., Ltd.) Can be used.

  Such a polyether-modified polysiloxane compound can contain one or more kinds in the reaction solution, and the content in the reaction solution is preferably 0.05 to 3% by weight, more preferably Preferably it is 0.1 weight%-2 weight%.

[Long chain alkyl glycol ether]
The reaction liquid in the present invention can further use long-chain alkyl glycol ethers for the purpose of improving the wettability to the recording medium. Examples of the long-chain alkyl glycol ethers include alkyl glycol ethers having 5 to 8, preferably 6 alkyl chains.

  Specific examples of such long-chain alkyl glycol ethers include, for example, ethylene glycol mono n-pentyl ether, ethylene glycol mono iso-pentyl ether, ethylene glycol mono neopentyl ether, ethylene glycol mono n-hexyl ether, ethylene glycol Monoiso-hexyl ether, diethylene glycol mono n-pentyl ether, diethylene glycol mono iso-pentyl ether, diethylene glycol mono neopentyl ether, diethylene glycol mono n-hexyl ether, diethylene glycol mono iso-hexyl ether, triethylene glycol mono n-pentyl ether, tri Ethylene glycol monoiso-pentyl ether, triethylene glycol mononeope Tyl ether, triethylene glycol mono n-hexyl ether, triethylene glycol mono iso-hexyl ether, propylene glycol mono n-pentyl ether, propylene glycol mono iso-pentyl ether, propylene glycol mono neopentyl ether, propylene glycol mono n-hexyl ether , Propylene glycol mono iso-hexyl ether, dipropylene glycol mono n-pentyl ether, dipropylene glycol mono iso-pentyl ether, dipropylene glycol mono neopentyl ether, dipropylene glycol mono n-hexyl ether, dipropylene glycol mono iso- Hexyl ether, tripropylene glycol mono n-pentyl ether, tripropylene Recall mono iso-pentyl ether, tripropylene glycol mono neopentyl ether, tripropylene glycol mono n-hexyl ether, tripropylene glycol mono iso-hexyl ether, diethylene glycol mono-2-ethylhexyl ether, triethylene glycol mono-2-ethylhexyl ether And tetraethylene glycol mono-2-ethylhexyl ether. These glycol ethers may be added alone or in combination of two or more.

  In particular, ethylene glycol mono n-hexyl ether, diethylene glycol mono n-hexyl ether, triethylene glycol mono n in terms of excellent wettability with respect to a low water-absorbing recording medium and excellent drying properties after coating. -Hexyl ether, propylene glycol mono n-butyl ether, dipropylene glycol mono n-butyl ether, and tripropylene glycol mono n-butyl ether are preferable. Among them, the most preferable in terms of uniform wettability, dryability after application, and water solubility. Diethylene glycol mono n-hexyl ether is well balanced.

  The content of the long-chain alkyl glycol ether is preferably 10% by weight or less, more preferably 8% by weight or less, and still more preferably 4% by weight or less in the reaction solution. If it exceeds 10% by weight, the long-chain alkyl glycol ether is less likely to evaporate, the drying characteristics after the reaction solution is applied to the recording medium are deteriorated, and the water solubility is lowered, so that it is difficult to dissolve in the reaction solution. Become.

[Diacetylenetetraol]
The reaction liquid in the present invention can further use diacetylene tetraol represented by the general formula of the following formula (2) for the purpose of further improving the wettability to the recording medium.

  As the diacetylene tetraol represented by the general formula of the above formula (2), for example, a commercially available product of “Surfinol MD-20” (trade name, manufactured by Air Products and Chemicals Inc.) can also be used.

  The diacetylene tetraol has a great effect on improving the wettability of the reaction solution with respect to the recording medium, but on the other hand, it is difficult to dissolve in water and a dissolution aid is required when it is contained in the reaction solution. As the solubilizing agent for diacetylene tetraol, the above-mentioned long-chain alkyl glycol ethers are effective, and in particular, ethylene glycol mono n-hexyl ether, diethylene glycol mono n-hexyl ether, triethylene glycol mono n-hexyl ether. , Propylene glycol mono n-butyl ether, dipropylene glycol mono n-butyl ether, tripropylene glycol mono n-butyl ether are effective as a solubilizing agent, uniform wettability with respect to a recording medium with low water absorption, and drying property after coating. Good balance in terms.

  The content of the diacetylene tetraol is preferably 0.01% to 0.6% by weight, more preferably 0.05% to 0.3% by weight in the reaction solution.

[1,2-alkanediol]
In the reaction solution of the present invention, 1,2-alkanediol can be further used for the purpose of improving the clogging recovery property of the long-chain alkyl glycol ethers and the reaction solution.

  As the 1,2-alkanediol, an optionally branched 1,2-alkanediol having 5 or 6 carbon atoms is preferable, and 4-methyl-1,2-pentanediol, 1,2-pentanediol, Examples include 3,3-dimethyl-1,2-butanediol and 1,2-hexanediol. Among these, 1,2-hexanediol is particularly preferred as a solubilizing agent for long-chain alkyl glycol ethers in water from the viewpoint of improving clogging recovery of the reaction solution.

  The 1,2-alkanediol is preferably 1 to 10% by weight, more preferably 2 to 8% by weight in the reaction solution. If it exceeds 15% by weight, it will be difficult to evaporate, and the reaction solution applied to the recording medium will be difficult to dry.

[Polyhydric alcohols and sugars]
The reaction liquid in the present invention can further contain a wetting agent to the extent that the drying property after application to the recording medium is not lowered for the purpose of improving clogging recovery. As the wetting agent, polyhydric alcohols and / or saccharides can be used. Specific examples of the polyhydric alcohols include glycerin, ethylene glycol, diethylene glycol, triethylene glycol, trimethylolpropane, 1,5-pentanediol, 1,2,6-hexatriol and the like. Specific examples of the saccharide include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), and polysaccharides. More specifically, glucose, mannose, fructose, ribose, xylose, arabinose, galactose, Examples thereof include aldonic acid, glucitol, (sorbit), maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature, such as alginic acid, α-cyclodextrin, and cellulose. The derivatives of these saccharides are represented by the reducing sugars of the saccharides described above (for example, sugar alcohol (general formula HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). ), Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thiosaccharides, etc.). Specific examples include maltitol, sorbitol, xylitol and the like.

  The content of the wetting agent in the reaction solution is preferably 0.1% by weight to 10% by weight, and more preferably about 0.5% by weight to 6% by weight. If it is this range, even if it is a low water absorption recording medium, the drying property after application | coating will not be reduced.

[Other components of the reaction solution]
The reaction liquid in the present invention contains water as a main solvent. It is preferable to use pure water or ultrapure water such as ion exchange water, ultrafiltration water, reverse osmosis water, or distilled water. In particular, water obtained by sterilizing these waters by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria is prevented over a long period of time.

  The reaction liquid in the present invention can further contain an organic amine, and the pH of the reaction liquid can be easily adjusted to a suitable range. As the organic amine, a tertiary amine can be preferably used. Examples of the tertiary amine include alkanolamines such as triethanolamine and tripropanolamine. The reaction solution according to the present invention preferably has a pH of 7 to 10, particularly 7.5 to 9. If it exists in this range, the member erosion with respect to the use member of an inkjet apparatus can be prevented. In particular, when the pH is in a range exceeding 12, the storage stability of the reaction solution may be significantly lowered.

  The content of the organic amine is 0.01% by weight or more in the reaction solution, but it can improve the wettability to the recording surface of the recording medium when forming a recorded image, and can stably discharge the ink. From the viewpoints of performance, storage stability, and high-speed printing, it is preferably 0.05 wt% to 5.0 wt%, more preferably 0.1 wt% to 2.0 wt%.

  The reaction solution in the present invention may further contain dissolution aids, preservatives, fungicides, antioxidants, conductivity modifiers, viscosity modifiers, surface tension modifiers, oxygen absorbers and the like.

  Examples of preservatives and fungicides include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, sodium dehydroacetate, 1,2-dibenzthiazoline-3-one ( ICI's Proxel CRL, Proxel BND, Proxel GXL, Proxel XL-2, Proxel TN) and the like.

  Examples of solubilizers include alcohols such as ethanol, propanol and butanol, amines such as diethanolamine and morpholine and derivatives thereof, inorganic salts such as potassium hydroxide, sodium hydroxide and lithium hydroxide, ammonium hydroxide, Quaternary ammonium hydroxide (such as tetramethylammonium), pyrrolidones such as N-methyl-2-pyrrolidone and 2-pyrrolidone and / or lactones such as γ-butyrolactone, urea such as urea, thiourea and tetramethylurea , Allophanates such as allophanate and methyl allophanate, biurets such as biuret, dimethyl biuret and tetramethyl biuret.

[Ink composition]
The ink composition in the present invention means a black ink composition when performing monochrome printing, and a color ink composition, specifically a yellow ink composition and a magenta ink composition when performing color printing. And a cyan ink composition, and optionally a black ink composition.

  The ink composition in the present invention comprises at least water, a colorant, and a resin emulsion.

  As water contained in the ink composition of the present invention, “water” described in the above-mentioned reaction liquid section can be used.

  The colorant contained in the ink composition according to the present invention may be either a dye or a pigment, but in the case where the penetration of the coloring component in the ink is suppressed by the action of insolubilization or thickening of the ink composition. Are more advantageous for pigments dispersed than for dyes dissolved in aqueous media. Also, a pigment is preferable from the viewpoint of light resistance and water resistance.

  As dyes, use various dyes that are usually used for inkjet recording, such as direct dyes, acid dyes, food dyes, basic dyes, reactive dyes, disperse dyes, vat dyes, soluble vat dyes, and reactive disperse dyes. Can do.

  As the pigment, carbon black (CI pigment black 7) such as furnace black, lamp black, acetylene black and channel black, iron oxide, titanium oxide and the like can be used. Organic pigments include insoluble azo pigments, condensed azo pigments, azo lakes and chelate azo pigments, phthalocyanine pigments, perylene and perinone pigments, anthraquinone pigments, quinacridone pigments, dioxane pigments, thioindigo pigments, isoindolinone pigments, and quinophthalone. Polycyclic pigments such as pigments, dye chelates (for example, basic dye chelates, acid dye chelates, etc.), dye lakes (basic dye lakes, acid dye lakes), nitro pigments, nitroso pigments, aniline black, Daylight fluorescent pigments can be used. The above pigments can be used alone or in combination of two or more.

  Carbon black is preferred as the pigment used in the black ink composition. Specific examples of carbon black include # 2300, # 900, HCF88, # 33, # 40, # 45, # 52, MA7, MA8, MA100, # 2200B manufactured by Mitsubishi Chemical, Raven 5750, 5250 , 5000, 3500, 1255, 700, etc., Regal 400R, 330R, 660R, Mogu L, 700, Monarch 800, 880, 900, 1000, 1100, 1300, manufactured by Cabot Corporation , 1400, etc., Color Black FW1, FW2V, FW18, FW200, Color Black S150, S160, S170, Printex 35, U, V, 140U, Special Black 6, 5 4A, same Etc. can be mentioned, may be used as these one or a mixture of.

  The color ink composition preferably includes at least a yellow ink composition, a magenta ink composition, and a cyan ink composition. Examples of the pigment of the color ink composition include pigment yellow, pigment red, pigment violet, pigment blue and the like described in the color index.

  Specifically, for example, C.I. I. Pigment Yellow 1, 3, 12, 13, 14, 17, 24, 34, 35, 37, 42, 53, 55, 74, 81, 83, 95, 97, 98, 100, 101, 104, 108, 109, 110, 117, 120, 128, 138, 147, 150, 153, 155, 174, 180, 188, 198; I. Pigment red 1,3,5,8,9,16,17,19,22,38,57: 1,90,112,122,123,127,146,184,202,207,209; I. Pigment Bio Red 1,3,5: 1, 16, 19, 23, 38; I. Pigment Blue 1, 2, 15, 15: 1, 15: 2, 15: 3, 15: 4, 16; I. Pigment Black 1, 7, etc., and an ink composition can also be formed using a plurality of pigments. In particular, the organic pigment contained in the yellow ink composition is C.I. I. Pigment Yellow 74, 109, 110, 128, 138, 147, 150, 155, 180, and 188, and the organic pigment contained in the magenta ink composition includes C.I. I. Pigment red 122, 202, 207, 209, C.I. I. An organic pigment containing at least one selected from pigment violet 19 and contained in the cyan ink composition is C.I. I. It is preferable to include at least one selected from CI Pigment Blue 15, 15: 1, 15: 2, 15: 3, 15: 4, and 16.

  Further, any pigment not described in the color index can be used as long as it is insoluble in water.

  According to a preferred embodiment of the present invention, these pigments are preferably added to the ink as a pigment dispersion obtained by dispersing the pigment in an aqueous medium with a dispersant or a surfactant. As a preferable dispersant, a dispersant conventionally used for preparing a pigment dispersion, for example, a polymer dispersant can be used.

  Preferred examples of the dispersant or surfactant include polyacrylic acid, polymethacrylic acid, acrylic acid-acrylonitrile copolymer, vinyl acetate-acrylic acid ester copolymer, acrylic acid-acrylic acid alkyl ester copolymer, styrene. -Acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-acrylic acid-alkyl acrylate copolymer, styrene-methacrylic acid-alkyl acrylate copolymer, styrene-α-methylstyrene-acrylic acid Copolymer, styrene-α-methylstyrene-acrylic acid-acrylic acid alkyl ester copolymer, styrene-maleic acid copolymer, vinylnaphthalene-maleic acid copolymer, vinyl acetate-ethylene copolymer, vinyl acetate- Fatty acid vinyl ethylene copolymer, vinyl acetate-male Examples thereof include an acid ester copolymer, a vinyl acetate-crotonic acid copolymer, and a vinyl acetate-acrylic acid copolymer.

  According to a preferred embodiment of the present invention, these copolymers preferably have a weight average molecular weight of about 3,000 to 50,000, more preferably about 5,000 to 30,000, and most preferably 7,000. 000 to 15,000.

  The addition amount of the dispersant may be appropriately added as long as the pigment is stably dispersed and the other effects of the present invention are not lost. According to a preferred embodiment of the present invention, the amount used is preferably in the range of about 1: 0.06 to 1: 3, more preferably in the range of about 1: 0.125 to 1: 3 as pigment: dispersant. .

  The amount of the pigment added to the ink is preferably about 0.5 to 25% by weight, more preferably about 2 to 15% by weight.

  According to a preferred embodiment of the present invention, the ink composition preferably comprises a resin emulsion. Here, the resin emulsion means an emulsion in which the continuous phase is water and the dispersed phase is the following resin component. As the resin component of the dispersed phase, acrylic resin, vinyl acetate resin, styrene-butadiene resin, vinyl chloride resin, acrylic-styrene resin, butadiene resin, styrene resin, crosslinked acrylic resin, crosslinked styrene resin, Examples thereof include benzoguanamine resin, phenol resin, silicone resin, and epoxy resin.

  According to a preferred embodiment of the present invention, the resin is preferably a polymer having both a hydrophilic part and a hydrophobic part. The particle size of these resin components is not particularly limited as long as an emulsion is formed, but is preferably about 150 nm or less, and more preferably about 5 nm to 100 nm.

  These resin emulsions can be obtained by subjecting a resin monomer to dispersion polymerization in water, optionally with a surfactant. For example, an acrylic resin or a styrene-acrylic resin emulsion can be obtained by dispersion-polymerizing (meth) acrylic acid ester, or (meth) acrylic acid ester and styrene together with a surfactant in water. The mixing ratio of the resin component and the surfactant is usually preferably about 10: 1 to 5: 1. When the amount of the surfactant used is in the above range, better water resistance and penetrability of the ink can be obtained. The surfactant is not particularly limited, but preferable examples include anionic surfactants (for example, sodium dodecyl benzene sulfonate, sodium laurate, ammonium salt of polyoxyethylene alkyl ether sulfate), nonionic surfactants ( For example, polyoxyethylene alkyl ether, polyoxyethylene alkyl ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkyl phenyl ether, polyoxyethylene alkyl amine, polyoxyethylene alkyl amide, etc.). A mixture of seeds or more can be used. Alternatively, acetylene glycol (olefin Y and Surfinol 82, 104, 440, 465, and 485 (all trade names, manufactured by Air Products and Chemicals Inc.)) can be used.

  The ratio of the resin as the dispersed phase component to water is suitably 60 to 400 parts by weight, preferably 100 to 200 parts by weight, based on 100 parts by weight of the resin.

  Commercially available resin emulsions can also be used. For example, Microgel E-1002, E-5002 (styrene-acrylic resin emulsion, manufactured by Nippon Paint Co., Ltd.), Boncoat 4001 (acrylic resin emulsion, Dainippon) Manufactured by Ink Chemical Co., Ltd.) Boncoat 5454 (styrene-acrylic resin emulsion, manufactured by Dainippon Ink & Chemicals, Inc.), SAE-1014 (styrene-acrylic resin emulsion, manufactured by Nippon Zeon Co., Ltd.), Cybinol SK-200 ( Acrylic resin emulsion, manufactured by Seiden Chemical Co., Ltd.).

  The ink used in the present invention preferably contains a resin emulsion such that the resin component is 0.1% to 40% by weight of the ink, more preferably 1% to 25% by weight. .

  The resin emulsion has an effect of suppressing the penetration of the coloring component by the interaction with the polyvalent metal ion and further promoting the fixing to the recording medium. Further, depending on the type of the resin emulsion, a film is formed on the recording medium, and it has an effect of improving the abrasion resistance of the printed matter.

According to a preferred embodiment of the present invention, the ink composition can include a thermoplastic resin in the form of a resin emulsion. Here, the thermoplastic resin has a softening temperature of 50 ° C to 250 ° C, preferably 60 ° C to 200 ° C. Here, the term softening temperature is the temperature at which the glass transition point, melting point, and viscosity of the thermoplastic resin become 10 ¹¹ poise to 10 ¹² poise, pour point, and the minimum film-forming temperature (MFT) in the form of a resin emulsion. ) Means the lowest temperature. When an ink composition containing such a resin emulsion is used, it is preferable to carry out a heating step in which the recording medium after recording is heated at a temperature equal to or higher than the softening temperature of the thermoplastic resin.

  In addition, it is preferable to select a resin that forms a film having strong water resistance and abrasion resistance when heated to a softening or melting temperature or higher and cooled.

  Specific examples of water-insoluble thermoplastic resins include polyacrylic acid, polymethacrylic acid, polymethacrylic acid ester, polyethylacrylic acid, styrene-butadiene copolymer, polybutadiene, acrylonitrile-butadiene copolymer, and chloroprene copolymer. Polymer, fluororesin, vinylidene fluoride, polyolefin resin, cellulose, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, polystyrene, styrene-acrylamide copolymer, polyisobutyl acrylate, polyacrylonitrile, polyacetic acid Vinyl, polyvinyl acetal, polyamide, rosin resin, polyethylene, polycarbonate, vinylidene chloride resin, cellulose resin, vinyl acetate resin, ethylene-vinyl acetate copolymer, vinyl acetate-acrylic copolymer, Vinyl resins, polyurethane, rosin ester and the like are not limited thereto.

  Specific examples of low molecular weight thermoplastic resins include polyethylene wax, montan wax, alcohol wax, synthetic oxide wax, α-olefin-maleic anhydride copolymer, carnauba wax and other animal and plant waxes, lanolin, paraffin wax, microcrystalline. A wax etc. are mentioned.

  As such a resin emulsion, a known resin emulsion can also be used. For example, JP-B-62-1426, JP-A-3-56573, JP-A-3-79678, JP-A-3-160068. The resin emulsions described in JP-A-4-18462 and the like can be used as they are.

  According to a preferred embodiment of the present invention, the ink composition can contain an alginic acid derivative. Preferable examples of the alginic acid derivative include alginic acid alkali metal salts (for example, sodium salts and potassium salts), alginic acid organic salts (for example, triethanolamine salts), and alginic acid ammonium salts.

  The amount of the alginic acid derivative added to the ink composition is preferably about 0.01 wt% to 1 wt%, more preferably about 0.05 wt% to 0.5 wt%.

  The reason why a good image can be obtained by the addition of an alginic acid derivative cannot be determined, but the polyvalent metal salt present in the reaction solution reacts with the alginic acid derivative in the ink composition, changes the dispersion state of the colorant, and the colorant This is thought to be due to the fact that the fixing to the recording medium is promoted.

Further, the ink composition used in the present invention may contain an inorganic oxide colloid. Preferable examples of the inorganic oxide colloid include colloidal silica and alumina colloid. These are generally colloidal solutions in which ultrafine particles such as SiO ₂ and Al ₂ O ₃ are dispersed in water or an organic solvent. As a commercially available inorganic oxide colloid, the dispersion medium is water, methanol, 2-propanol, n-propanol, xylene or the like, and the particle diameter of particles such as SiO ₂ and Al ₂ O ₃ is 5 nm to 100 nm. Things are common. In many cases, the pH of the inorganic oxide colloidal solution is adjusted to be acidic or alkaline rather than neutral. This is because the stable dispersion region of the inorganic oxide colloid exists on the acidic side or alkaline side. When added to the ink composition, the pH of the stable dispersion region of the inorganic oxide colloid and the pH of the ink are set. It is necessary to add in consideration.

  The addition amount of the inorganic oxide colloid in the ink composition is preferably 0.1 wt% to 15 wt%, and two or more kinds can be added.

  According to a preferred embodiment of the present invention, the ink composition preferably comprises an organic solvent. This organic solvent is preferably a low boiling point organic solvent, and preferred examples thereof include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, sec-butanol, tert-butanol, iso-butanol, Examples thereof include n-pentanol. A monohydric alcohol is particularly preferable. The low boiling point organic solvent has an effect of shortening the drying time of the ink.

  According to a preferred aspect of the present invention, the ink composition used in the present invention preferably further comprises a wetting agent composed of a high-boiling organic solvent. Preferred examples of the high boiling point organic solvent agent include ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, propylene glycol, butylene glycol, 1,2,6-hexanetriol, thioglycol, hexylene glycol, glycerin, Polyhydric alcohols such as trimethylolethane, trimethylolpropane, ethylene glycol monoethyl ether, ethylene glycol monobutyl ether, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, triethylene glycol monomethyl ether, triethylene glycol monoethyl Ether, triethylene glycol monobutyl ether Alkyl ethers of polyhydric alcohols such as urea, 2-pyrrolidone, N- methyl-2-pyrrolidone, 1,3-dimethyl-2-imidazolidinone, triethanolamine and the like.

  The amount of the wetting agent added is preferably 0.5% to 40% by weight of the ink, more preferably 2% to 20% by weight. The amount of the low-boiling organic solvent added is preferably 0.5% to 10% by weight of the ink, more preferably 1.5% to 6% by weight.

  According to a preferred embodiment of the present invention, the ink composition preferably contains a sugar. Examples of saccharides include monosaccharides, disaccharides, oligosaccharides (including trisaccharides and tetrasaccharides), and polysaccharides, preferably glucose, mannose, fructose, ribose, xylose, arabinose, galactose, aldonic acid, glucosiyl. (Sorbit), maltose, cellobiose, lactose, sucrose, trehalose, maltotriose, and the like. Here, the polysaccharide means a saccharide in a broad sense, and is used to include a substance that exists widely in nature, such as alginic acid, α-cyclodextrin, and cellulose.

The derivatives of these saccharides are represented by the reducing sugars of the saccharides described above (for example, sugar alcohol (general formula HOCH ₂ (CHOH) _n CH ₂ OH (where n represents an integer of 2 to 5)). ), Oxidized sugars (eg, aldonic acid, uronic acid, etc.), amino acids, thio sugars, etc. Particularly preferred are sugar alcohols, and specific examples thereof include maltitol, sorbit and the like.

  The content of these saccharides is suitably 0.1% to 40% by weight, preferably 0.5% to 30% by weight of the ink.

  In addition, you may add a pH adjuster, antiseptic | preservative, a fungicide, etc. as needed.

[Recording method]
[Inkjet recording system]
In the present embodiment, the “inkjet recording method” means a method in which a reaction liquid and an ink composition are ejected as droplets from a fine nozzle by an inkjet recording apparatus, and the droplets are attached to a recording medium. This will be specifically described below.

  As a first method, there is an electrostatic suction method, which applies a strong electric field between the nozzle and the acceleration electrode placed in front of the nozzle, and continuously ejects ink from the nozzle in the form of droplets. This is a method in which a print information signal is applied to the deflection electrode while the ink droplet is flying between the deflection electrodes for recording, or a method in which the ink droplet is ejected in response to the print information signal without being deflected.

  The second method is a method in which ink droplets are forcibly ejected by applying pressure to the ink liquid with a small pump and mechanically vibrating the nozzle with a crystal resonator or the like. The ejected ink droplet is charged simultaneously with the ejection, and a printing information signal is given to the deflection electrode and recorded while the ink droplet flies between the deflection electrodes.

  The third method is a method using a piezoelectric element, in which a pressure and a print information signal are simultaneously applied to an ink liquid by a piezoelectric element to eject and record ink droplets.

  The fourth method is a method in which the ink liquid is rapidly expanded in volume by the action of heat energy, and the ink liquid is heated and foamed with a microelectrode in accordance with a print information signal to eject and record ink droplets.

  Any of the above methods can be used in an ink jet recording method using the reaction liquid and ink composition of the present invention.

[Inkjet recording method for printing two liquids]
The ink jet recording method according to the present invention comprises a step of printing a reaction liquid and an ink composition on a recording medium using the above ink jet recording method.

  The reaction liquid and the ink composition may be applied to the recording medium in any order, that is, a method in which the reaction liquid is attached to the recording medium and then the ink composition is attached to the recording medium, the ink composition Both of the method of attaching the reaction liquid after printing and the method of mixing the reaction liquid and the ink composition immediately before or after the injection can be suitably performed.

  According to a preferred embodiment of the present invention, a method in which a reaction liquid is attached to a recording medium and then an ink composition is attached to the recording medium is more preferable from the viewpoint of suppressing bleeding, color bleeding, and printing unevenness.

  According to the ink jet recording method of the present invention, good printing can be realized by contacting the reaction liquid with the ink composition. The following is a hypothetical theory, and it is considered as follows if the reason is described on the condition that the present invention is not limited and interpreted. When the reaction liquid comes into contact with the ink composition, the polyvalent metal ions, polyallylamine and polyallylamine derivatives in the reaction liquid destroy the dispersed state of the colorant, resin emulsion, etc. in the ink composition, and the coloring component, resin emulsion. Aggregate etc. This aggregate is considered to suppress the penetration of the colorant into the recording medium. These are considered to realize an image having a high color density, less bleeding, and less printing unevenness. In addition, a color image has an advantage that non-uniform color mixing, that is, color bleeding, can be effectively prevented in a boundary area of different colors. At the same time, the cationic polyurethane in the reaction solution seems to have an effect of promoting adhesion of the colorant to the recording medium by forming a resin film so as to wrap the ink composition after adhering to the recording medium. Thereby, it is considered that excellent abrasion resistance of the recorded matter can be realized. The above mechanism is merely an assumption, and the present invention is not construed as being limited to this mechanism.

  Regarding the attachment of the reaction liquid to the recording medium, either a method of selectively attaching the reaction liquid only to a place where the ink composition is attached or a method of attaching the reaction liquid to the entire paper surface may be employed. . The former is economical because the consumption of the reaction liquid can be minimized, but a certain degree of accuracy is required at the position where both the reaction liquid and the ink composition are attached. On the other hand, in the latter case, the accuracy of the attachment position of the reaction liquid and the ink composition is relaxed compared to the former, but a large amount of the reaction liquid is attached to the entire paper surface, and the paper is likely to curl during drying. Accordingly, which method is adopted may be determined in consideration of the combination of the reaction liquid and the ink composition. When the former method is employed, the reaction liquid can be attached by an ink jet recording method.

  Further, the difference in application time between the reaction liquid and the ink composition is preferably 1 sec or less from the viewpoint of print quality. When the ink composition is printed after more than 1 sec since the reaction liquid is attached, the reaction liquid penetrates into the recording medium, resulting in a decrease in the aggregation reaction with the ink composition on the paper surface. In some cases, improvement in image quality such as color bleeding cannot be obtained.

  Further, the method of recording the reaction liquid and the ink composition on the recording medium may be performed by one pass or multipass. Here, one pass is a recording method in which all dots to be formed in the scanning area are recorded by one scanning of the recording head. That is, the reaction liquid and the ink composition are printed in one pass means that the dots of the reaction liquid and the ink composition to be recorded in the recording head scanning area complete the recording by one scanning of the recording head. That's what it means. Multi-pass is a method of recording dots to be recorded in the recording head scanning area by a plurality of recording head scans. Further, in the one-pass recording method, after the recording head is scanned once in the main scanning direction to record dots, the entire image is formed by repeatedly moving the recording medium by the recording area in the sub-scanning direction. And a method of forming an image by fixing the recording head and scanning the recording medium, and any of them can be suitably used. It is obvious to those skilled in the art that recording in one pass enables high-speed printing and increases the productivity of recorded matter. However, as described above, before the reaction liquid penetrates into the recording medium, it is ensured. In addition, since an agglomeration reaction between the reaction liquid and the ink composition occurs on the recorded material, it is possible to improve an effect of suppressing bleeding and color bleeding. In addition, the reaction solution used in the present invention is excellent in wettability with respect to the recording medium, and therefore the object can be realized with a small amount of the reaction solution.

  According to a preferred embodiment of the present invention, it is preferable to heat the recording medium to which the reaction liquid and / or the ink composition is attached. Specifically, the step of heating after attaching the reaction liquid to the recording medium and then printing the ink composition, or the step of heating after printing the ink composition on the recording medium and then printing the reaction liquid, Or the process of heating, after printing a reaction liquid and an ink composition on a recording medium is mentioned. By performing such a heat treatment, evaporation of moisture in the reaction liquid and the ink composition is promoted, and generation of wrinkles of the recording medium can be prevented, and further, occurrence of curling of the recording medium can be effectively prevented. Furthermore, the heating promotes the fusion of the cationic polyurethane in the reaction solution, and an excellent film can be formed, thereby further improving the abrasion resistance of the recorded matter. The heating temperature is preferably about 40 ° C to 150 ° C, more preferably about 40 ° C to 100 ° C.

  According to the preferable form of this invention, it is preferable that the surface tension of a reaction liquid is 20 mN / m-35 mN / m, and the surface tension of an ink composition is 25 mN / m-50 mN / m. According to this ink jet recording method, a good image can be obtained. Specifically, a printed image with little blurring, no printing unevenness, a high OD value, and excellent abrasion resistance can be obtained. It is also suitable for downsizing the recording head and increasing printing speed. Furthermore, the surface tension of the reaction liquid is preferably lower than the surface tension of the ink composition. By doing in this way, more consistent high quality printing can be obtained regardless of the order of attachment of the reaction liquid and the ink composition.

  The viscosity of the reaction liquid and the ink composition at 20 ° C. is preferably in the range of 1.5 mPa · s to 15 mPa · s, more preferably in the range of 1.5 mPa · s to 10 mPa · s. Preferably, the reaction liquid and the ink composition have substantially the same viscosity. For example, one viscosity is set to 50% to 200% of the other viscosity. Accordingly, when both the reaction liquid and the ink composition are ejected from the ink jet recording head, it is advantageous in that the recording head, the flow path structure, and the drive circuit can be made the same.

[Inkjet recording apparatus]
An ink jet recording apparatus for carrying out the ink jet recording method according to the present invention will be described below with reference to the drawings.

  The ink jet recording apparatus of FIG. 1 is an aspect in which an ink composition and a reaction liquid are stored in a tank, and the ink composition and the reaction liquid are supplied to a recording head via an ink tube. That is, the recording head 1 and the ink tank 2 are communicated with each other through the ink tube 3. Here, the inside of the ink tank 2 is partitioned, and an ink composition, and in some cases, a plurality of color ink composition rooms and a reaction liquid room are provided.

  The recording head 1 moves along a carriage 4 by a timing belt 6 driven by a motor 5. On the other hand, a recording medium 7 as a recording medium is placed at a position facing the recording head 1 by a platen 8 and a guide 9. In this embodiment, a cap 10 is provided. A suction pump 11 is connected to the cap 10 to perform a so-called cleaning operation. The sucked ink composition is stored in the waste ink tank 13 through the tube 12.

  An enlarged view of the nozzle surface of the recording head 1 is shown in FIG. A portion indicated by 100 is a nozzle surface 100 for the reaction liquid, and a first liquid discharge nozzle 21 for discharging the reaction liquid is provided in the vertical direction. On the other hand, the portion denoted by 101 is the nozzle surface 101 of the ink composition, and the yellow ink composition, the magenta ink composition, the cyan ink composition, and the ink composition discharge nozzles 22, 23, 24, and 25, respectively. A black ink composition is discharged.

  Further, an ink jet recording method using the recording head shown in FIG. 2 will be described with reference to FIG. The recording head 1 moves in the direction of arrow A. During the movement, the reaction liquid is discharged from the nozzle surface 100 (see FIG. 2), and a strip-shaped first liquid adhesion region 31 is formed on the recording medium 7. Next, the recording medium 7 is transferred to the paper feed direction arrow B by a predetermined amount. Meanwhile, the recording head 1 moves in the direction opposite to the arrow A in the figure and returns to the left end position of the recording medium 7. Then, the ink composition is printed on the reaction liquid adhesion area where the reaction liquid has already adhered, and the printing area 32 is formed.

  Further, as shown in FIG. 4, in the recording head 1, all the nozzles can be arranged in the horizontal direction. This configuration is suitable for one-pass printing. In the figure, reference numerals 41a and 41b denote reaction liquid discharge nozzles 41a and 41b. From the ink composition discharge nozzles 42, 43, 44, and 45, respectively, a yellow ink composition, a magenta ink composition, a cyan ink composition, and black An ink composition is ejected. In the recording head of such a mode, printing can be performed in both the forward path and the backward path in which the recording head 1 reciprocates on the carriage, and at a higher speed than when the recording head shown in FIG. 2 is used. Printing is possible.

  Further, by adjusting the surface tension of the reaction liquid and the ink composition, high-quality printing can be obtained more consistently regardless of the order of attachment. In this case, it is possible to use one reaction liquid discharge nozzle (for example, the reaction liquid discharge nozzle 41b in the figure can be omitted), and further downsizing of the head and higher printing speed can be achieved.

  Further, some ink jet recording apparatuses are replenished with an ink composition by replacing a cartridge which is an ink tank. The ink tank may be integrated with the recording head.

  A preferred example of an ink jet recording apparatus using such an ink tank is shown in FIG. In the figure, the same members as those in the apparatus of FIG. In the embodiment of FIG. 5, the recording head 1a and the recording head 1b are integrated with the ink tank 2a and the ink tank 2b. Assume that the recording head 1a or the recording head 1b discharges the ink composition and the reaction liquid, respectively. The printing method may be basically the same as that of the apparatus shown in FIG. In this embodiment, the recording head 1a, the ink tank 2a, the recording head 1a, and the ink tank 2b move together on the carriage 4.

  Further, FIG. 6 shows a preferred example of an ink jet recording apparatus provided with a heater for heating a recording medium on which printing has been performed. FIG. 6 is the same as that shown in FIG. 1 except that the heater 14 is provided. The heater 14 may be a heater that contacts and heats the recording medium, or a heater that does not contact the recording medium, such as irradiating infrared rays or blowing hot air.

  According to a preferred aspect of the present invention, the ink jet recording apparatus further stores the reaction liquid and the ink composition, and the amount of the ink composition and the reaction liquid is such that the ink composition is consumed first. Are preferred.

  Moreover, according to another preferable aspect, the ink tank used for an inkjet recording device is provided. The ink tank may preferably be a replaceable cartridge type, and more preferably may be integrated with the recording head. In any of the embodiments, it is preferable that the reaction liquid and the ink composition are accommodated, and the amount of the ink composition and the reaction liquid is such that the ink composition is consumed first.

  Contrary to this aspect, when the reaction liquid is consumed before the ink composition, the reaction liquid is generally transparent, and thus consumed. It becomes difficult to know the time. That is, the fact that the reaction solution has been consumed is observed only by observing the print and the print quality is deteriorated, and thus the user is always required to observe the print quality.

  On the other hand, in the ink jet recording apparatus according to this aspect, since the ink composition itself is colored, its exhaustion can be easily known. Furthermore, since the reaction liquid does not run out before the ink composition is completely consumed, it is possible to perform an ink jet recording method that stably prints two liquids. On the other hand, it is conceivable to provide sensor means in the tank portion for storing the ink composition and the reaction liquid and observe the consumption thereof. In this aspect, such a complicated mechanism can be replaced with a very simple mechanism. It can be said that this is also valuable.

  In this embodiment, when a plurality of ink compositions are used, “the ink composition is consumed earlier than the reaction liquid” means that any one ink composition is consumed. As long as the reaction liquid still remains at that time, it does not necessarily mean that the reaction liquid must remain even when all of the plurality of ink compositions are consumed. It is preferable that the reaction solution remains even when all of the product is consumed.

[Recordings]
The recorded matter of this embodiment is recorded on a recording medium using at least the above-described inkjet recording method. By using the above-described ink jet recording method, this recorded matter has no bleeding, color bleeding, printing unevenness, etc., and excellent abrasion resistance with respect to a recording medium having a low water-absorbing paper support absorbing layer. Show quality.
The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to these examples.

  The following evaluations 1 to 8 were performed using the reaction liquids (1 to 15) shown in Table 1.

The printed matter used in the evaluation is an “OK Top Coat N” (made by Oji Paper Co., Ltd.), which is a type of coated paper, as a recording medium using an inkjet printer PX-G930 (manufactured by Seiko Epson Corporation). It was created by printing at a resolution of 360 dpi. The water absorption of this “OK topcoat N” from the start of contact by the Bristow method to 20 msec ^1/2 was 6 ml / m ² . The black and cyan ink compositions were prepared with the constituents listed in Table 2.

[Evaluation 1 Application property]
Using the printer, solid printing was performed on the coated paper with the reaction solution so that the discharge amount per unit area was 1 g / m ² . The application state of the reaction solution immediately after printing was visually observed and evaluated according to the following criteria. A: Evenly applied without unevenness.
C: Coating unevenness is conspicuous.

[Evaluation 2 Bleeding]
Using the printer, solid printing was performed on the coated paper with the reaction liquid so that the discharge amount was 0.5 g / m ^2, and then the black ink composition was used and the discharge amount was 20 ng / dot. The character of point was printed. After leaving at 25 ° C. for 24 hours, the presence or absence of bleeding in the characters was examined.
A: There is no blur and it is clear.
B: Whisker-like bleeding is observed.
C: Bleeding occurs so that the outline of the character is not clear.

[Evaluation 3 Color Bleed]
Using the printer, solid printing was performed with the reaction liquid so that the discharge amount was 0.5 g / m ^{2 on the} coated paper, and then an 80% duty patch was printed with the cyan ink composition. At the same time, with the black ink composition, 6-point characters were printed on this patch at a discharge amount of 20 ng / dot. The obtained printed matter was examined visually for the presence or absence of uneven color mixing at the boundary between characters.
A: The color is not mixed and the boundary is clear.
B: A whisker-like color mixture occurred.
C: Colors are mixed so that the characters and outlines are not clear.

[Evaluation 4 Printing unevenness]
Using the printer, solid printing was performed on the coated paper with the reaction solution so that the discharge amount was 0.5 g / m ^2, and then 100% duty solid printing with a cyan ink composition was performed. . After standing at 25 ° C. for 24 hours, the OD values at any five points of the printed matter are measured using Spectrolino (manufactured by Gretag), and the maximum and minimum values of the five OD values are obtained. The difference in values was calculated and evaluated based on the following criteria.
A: The difference between the maximum value and the minimum value is less than 0.2.
B: The difference between the maximum value and the minimum value is 0.2 or more and less than 0.4.
C: The difference between the maximum value and the minimum value is 0.4 or more.

[Evaluation 5 Abrasion resistance]
Printing was performed on the coated paper using an apparatus having the configuration shown in FIG. 6 provided with an inkjet head used in the printer. Solid printing was performed with the reaction solution so that the discharge amount was 0.5 g / m ^2, and then 100% duty solid printing with a cyan ink composition was performed (sample X; no heating). Furthermore, after that, the printed matter was heated to 70 ° C. by passing through the heater 14 to prepare a separate printed matter (sample Y; heated). Each print part of sample X and sample Y was rubbed with a finger at 25 ° C. for 5 minutes and 60 minutes after printing, and the state of the printed surface and the ink attached to the finger were visually observed. The rub resistance including the drying property was evaluated based on the following criteria.
A: The printing surface does not change and ink does not adhere to the finger.
B: The ink on the printing surface slightly drops, but the ink does not adhere to the finger.
C: The ink on the printing surface drops and the ink adheres to the finger.

[Evaluation 6 Storage stability]
The reaction solution was placed in a glass bottle and sealed, and then allowed to stand at 40 ° C. for 2 weeks. Visual observation of the presence or absence of foreign matter (floating matter or sediment) after standing, and for those that do not generate foreign matter, investigate further changes in physical properties (viscosity, surface tension, pH), and storage stability based on the following criteria Evaluated.
A: No foreign matter is generated, and there is no change in physical properties.
B: No foreign matter is generated, but the physical properties slightly change.
C: Foreign matter is generated or the physical properties are remarkably changed.

[Evaluation 7: Discharge stability]
The reaction solution was filled in the printer, and images with mixed characters and graphics were continuously printed on A4 paper. If “bending flight” or “missing” occurs during printing, a cleaning operation is executed. If “flight bend” and “missing” did not correct even after performing the cleaning operation, the number of printed sheets was examined, and discharge stability was evaluated based on the following criteria.
A: The number of printed sheets is 10,000 or more until the flight bend does not return.
B: The number of printed sheets until the flying bend does not return is 5000 or more and less than 10,000.
C: The number of printed sheets until the flight bend does not return is less than 5000.

[Evaluation 8: Clogging recovery ability]
The reaction solution was filled in the printer, and after confirming that all the nozzles were ejected normally, the printer was stopped, and the printer head was left in a 40 ° C. environment for 24 hours without being capped. After leaving, the number of cleanings required until the reaction solution was discharged again from all nozzles was examined, and clogging recovery was evaluated based on the following criteria.
A: All nozzles were recovered by cleaning within two times.
B: All nozzles were recovered after 3 to 6 cleanings.
C: All nozzles could not be recovered by cleaning 6 times.

  Table 3 shows the results of the above evaluations.

  The present invention is capable of inkjet discharge and has a high-quality recorded image free from bleeding, color bleed, printing unevenness, and the like, and excellent in abrasion resistance with respect to a recording medium having an absorbent layer of a paper support with low water absorption. In addition, it has industrial applicability as an ink jet recording method and recorded matter for printing two liquids using a reaction liquid having excellent recording stability, ejection stability, and clogging recovery characteristics. .

FIG. 2 is a diagram illustrating an ink jet recording apparatus that performs the method according to the present invention. In this embodiment, the recording head and the ink tank are independent from each other, and the ink composition and the first liquid are supplied to the recording head through an ink tube. . FIG. 2 is an enlarged view of a nozzle surface of a recording head, in which 100 is a nozzle surface 100 of a reaction liquid, and 101 is a nozzle surface 101 of an ink composition. It is a figure explaining the inkjet recording using the recording head of FIG. In the figure, reference numeral 31 denotes a first liquid adhesion area 31 and reference numeral 32 denotes a printing area 32 in which an ink composition is printed on the first liquid adhered. FIG. 9 is a diagram illustrating another aspect of the recording head, in which all the discharge nozzles are arranged in the horizontal direction. 1 is a diagram showing an ink jet recording apparatus that performs a method according to the present invention, and in this embodiment, a recording head and an ink tank are integrated. FIG. FIG. 2 is a diagram showing an ink jet recording apparatus for performing the method according to the present invention, and in this embodiment, a heater 14 is provided as a heating means for heating a recording medium after an image is recorded.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 1a, 1b ... Recording head, 2, 2a, 2b ... Ink tank, 3 ... Ink tube, 4 ... Carriage, 5 ... Motor, 6 ... Timing belt, 7 ... Recording medium, 8 ... Platen, 9 ... Guide, 10 DESCRIPTION OF SYMBOLS ... Cap, 11 ... Suction pump, 12 ... Tube, 13 ... Waste ink tank, 14 ... Heater as heating means, 21 ... First liquid discharge nozzle, 22, 23, 24, 25, 42, 43, 44, 45 ... Ink composition discharge nozzle, 31... First liquid adhesion area, 32... Print area, 41 a, 41 b... Reaction liquid discharge nozzle, 100, 101.

Claims (11)

An ink jet recording method for performing printing by attaching a reaction liquid and an ink composition to a recording medium,
The recording medium has an absorption layer of a paper support in which the water absorption within 30 msec ^1/2 from the start of contact in the Bristow method is 30 ml / m ² or less, and the reaction liquid is a polyvalent metal At least one selected from a salt, a polyallylamine and a polyallylamine derivative, a cationic polyurethane, and a polyether-modified polysiloxane compound, and the ink composition is colored with water An ink jet recording method comprising an agent and resin emulsion particles.   2. The ink jet recording method according to claim 1, wherein the polyvalent metal salt is at least one selected from sulfate, nitrate and carboxylate. The inkjet recording method according to claim 1, wherein the polyether-modified polysiloxane compound is a polyether-modified polysiloxane compound represented by a general formula of the following formula (1).

  The ink jet recording method according to any one of claims 1 to 3, wherein the reaction liquid further contains a long-chain alkyl glycol ether.   The ink jet recording method according to claim 4, wherein the content of the long-chain alkyl glycol ether in the reaction solution is 10% by weight or less. 6. The ink jet recording method according to claim 1, wherein the reaction liquid further contains diacetylene tetraol represented by the following general formula (2).

  The ink jet recording method according to claim 1, wherein the reaction liquid further contains 1,2-alkanediol.   The reaction solution further comprises a polyhydric alcohol and / or saccharide as a wetting agent, and the content of the polyhydric alcohol and / or saccharide in the reaction solution is 0.1 wt% to 10 wt%. The ink jet recording method according to claim 1, wherein the ink jet recording method is characterized in that:   The inkjet recording method according to claim 1, wherein the colorant of the ink composition is a pigment.   10. The method according to claim 1, further comprising a step of heating the recording medium to which the reaction liquid and / or the ink composition is attached at 40 ° C. to 150 ° C. 10. Inkjet recording method.   A recorded matter recorded by the ink jet recording method according to claim 1.

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