JP2012149235A - Ink composition for inkjet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition for inkjet to form a desensitizer layer in carbonless copy paper by an inkjet recording method.SOLUTION: The ink compositions for inkjet are characterized by including a water-soluble organic desensitizer, a water-insoluble resin and water, wherein the content of the water-soluble organic desensitizer is 15-45 mass%, and composed of one or more compounds selected from the group consisting of polyethylene glycol, triethylene glycol monobutyl ether, monoethanolamine, diethanolamine, triethanolamine and polypropylene glycol, and wherein the ink compositions for inkjet further include a water-soluble organic solvent, and a recorded product is recorded by the inkjet recording method using any one of the ink compositions for inkjet.

Description

  The present invention relates to an inkjet ink composition containing a desensitizer for carbonless copying paper.

  Carbonless copy paper consists of an upper paper having a microcapsule layer encapsulating a color former on the back surface and a lower paper having a color developer layer on the surface when contacting with the color former. It is a paper that is stacked so that the two layers face each other. Due to the writing pressure or printing pressure, the microcapsule is broken, and the color former and the developer that have been encapsulated react to develop color. Further, by using a medium sheet provided with a developer layer on the front surface and a microcapsule layer containing a color former on the back surface, a plurality of sheets can be copied simultaneously.

  Carbonless paper often has areas where copying is not possible. For example, by forming a layer made of a desensitizer on the surface of the developer layer in a specific area where color development is unnecessary, copying can be prevented in that area. The desensitizer layer is generally formed by printing ink containing a desensitizer on a predetermined region of paper having a developer layer formed on the surface by gravure printing or offset printing.

  Carbonless copy paper is widely used for forms and the like. Form printing of forms and the like is performed by various methods such as an offset method and a relief printing method, but in recent years, it has been frequently performed by an ink jet recording method. In view of this, various inks have been developed for forming a desensitizer layer capable of form printing and the like by an inkjet recording method in the same manner as a paper surface on which a desensitizer layer is not formed. For example, Patent Document 1 reports a desensitized ink using a vehicle containing a glycol solvent having a boiling point of 100 ° C. or higher and a cationic resin, and containing an acrylic photocurable component or the like with respect to this vehicle. The desensitizing ink has excellent ink-jet ink absorbability, and when the ink-jet printing is performed on the surface of the desensitizing agent layer formed by printing the desensitizing ink by offset printing or the like, the desensitizing agent layer No bleeding of the printed image occurs, and the water resistance of the printed inkjet ink is improved. In addition, for example, Patent Document 2 discloses a method of forming the desensitizer layer itself by an ink jet recording method.

JP 2002-226757 A JP-A-7-223314

  Letterpress printing and offset printing require platemaking, and are inferior in economical efficiency of small lot printing. In contrast, inkjet printing does not require plate making, and can be printed in a relatively short period of time. The degree of freedom for changing the form is great, and is optimal for small lot printing. For this reason, it is desirable that the desensitizer layer can be formed by ink jet printing.

  In an inkjet ink, it is important to be excellent in inkjet ejection characteristics (smooth ejection without clogging the nozzles). For this reason, in the inkjet ink containing the desensitizer described in Patent Document 2, the desensitizer is dissolved in the liquid medium. However, a desensitizer layer formed by using a water-soluble or water-miscible desensitizer has a problem that water resistance is poor and a sufficient desensitizing action is hardly exhibited.

  Therefore, the subject in this invention is providing the ink composition for inkjets for forming the desensitizer layer excellent in water resistance on a carbonless copy paper.

In order to solve this problem, the present invention firstly contains a water-soluble organic desensitizer, a water-insoluble resin, and water, and the content of the water-soluble organic desensitizer is 15 to 45 mass. %, An ink-jet ink composition is provided.
In the present invention, secondly, the water-soluble organic desensitizer is selected from the group consisting of polyethylene glycol, triethylene glycol monobutyl ether, monoethanolamine, diethanolamine, triethanolamine, and polypropylene glycol, or The first ink-jet ink composition is provided in two or more types.
The present invention thirdly provides the first or second ink-jet ink composition further comprising a water-soluble organic solvent.
Fourth, the water-soluble organic solvent is one or more selected from the group consisting of alcohols, polyhydric alcohols, ketones, ethers, esters, and glycol ethers. The ink composition for inkjet according to any one of the first to third is.
In the present invention, fifthly, the water-soluble organic desensitizer is one or more selected from the group consisting of polyethylene glycol and triethylene glycol monobutyl ether, and the water-soluble organic solvent is ethanol and The third inkjet ink composition is one or more selected from the group consisting of diethylene glycol ethyl methyl ether.
Sixth, the water-insoluble resin is selected from the group consisting of polyester resin, urethane resin, acrylic resin, polyvinyl alcohol, styrene-acrylic resin, polyvinylpyrrolidone, acrylic-urethane copolymer, and polyethyleneimine. The ink composition for inkjet according to any one of the first to fifth, which is one kind or two or more kinds.
Seventhly, the present invention provides a recorded matter recorded by an ink jet recording method using any one of the first to sixth ink jet ink compositions.

  By using the inkjet ink composition of the present invention, a desensitizer layer having excellent water resistance can be easily formed on the surface of carbonless copying paper using a general inkjet printer.

The present invention will be described in detail below.
The inkjet ink composition of the present invention contains a water-soluble organic desensitizer, a water-insoluble resin, and water, and the content of the water-soluble organic desensitizer is 15 to 45% by mass. Features. In the inkjet ink composition of the present invention, since a water-soluble organic compound is used as a desensitizer, nozzle clogging is unlikely to occur, and the inkjet ink composition is very suitable as an ink composition for an inkjet printer.

  The water-soluble organic desensitizer used in the ink-jet ink composition of the present invention may be any water-soluble organic compound having a desensitizing action. In the present invention and the specification of the present application, the “water-soluble organic compound” includes an organic compound having high miscibility with water. The inkjet ink composition of the present invention may contain one type of water-soluble organic desensitizer or may contain two or more types of water-soluble organic desensitizers.

  The water-soluble organic desensitizer used in the present invention is specifically selected from the group consisting of polyethylene glycol, triethylene glycol monobutyl ether, monoethanolamine, diethanolamine, triethanolamine, and polypropylene glycol. It is preferable that it is a seed | species or 2 or more types. Among them, the water-soluble organic desensitizer preferably contains at least polyethylene glycol, triethylene glycol monobutyl ether, and polypropylene glycol, and is selected from the group consisting of polyethylene glycol, triethylene glycol monobutyl ether, and polypropylene glycol 1 More preferably, it is a seed or two or more, more preferably one or more selected from the group consisting of polyethylene glycol and triethylene glycol monobutyl ether. Since these organic compounds are conventionally used in inkjet inks, an inkjet ink composition with better inkjet ejection characteristics can be obtained by using these organic compounds. The molecular weight of polyethylene glycol used as a water-soluble organic desensitizer is not particularly limited. For example, polyethylene glycol having a number average molecular weight of 100 to 20000, preferably 200 to 10,000, more preferably 400 to 10,000 is used. It can be used suitably. Further, polyethylene glycols having different molecular weights may be used in combination.

  The content of the water-soluble organic desensitizer in the ink-jet ink composition of the present invention is such that the desensitizer layer formed by recording with the ink-jet ink composition using an ink-jet printer is sufficiently reduced. The concentration is not particularly limited as long as it exhibits a sensitizing action, and can be appropriately determined in consideration of the type of water-soluble organic desensitizer, the desired product characteristics of carbonless copying paper, and the like.

  If the content of the water-soluble organic desensitizer is too small, the desensitizing action tends to be insufficient. For example, the content of the water-soluble organic desensitizer in the inkjet ink composition of the present invention is preferably 15% by mass or more, and more preferably 20% by mass or more. On the other hand, when the content of the water-soluble organic desensitizer is too large, it is difficult to sufficiently mix other components for providing the ink-jet ink composition such as water and a wetting agent. It may be easy to become. For this reason, for example, the content of the water-soluble organic desensitizer in the ink-jet ink composition of the present invention is preferably 45% by mass or less, and more preferably 40% by mass or less.

  The inkjet ink composition of the present invention contains a water-insoluble resin together with a water-soluble organic desensitizer. By containing the water-insoluble resin, the water resistance of the desensitizer layer formed from the ink-jet ink composition is dramatically improved.

  The water-insoluble resin added to the ink-jet ink composition of the present invention does not impair the desensitization effect of the water-soluble organic desensitizer, and impairs the ink-jet characteristics such as the ink-jet ejection characteristics of the added ink composition. If it does not have, it will not specifically limit, It can select from well-known resin suitably and can be used. The inkjet ink composition of the present invention may contain one type of resin, or may contain two or more types of resins.

  Specific examples of the water-insoluble resin added to the ink-jet ink composition of the present invention include polyester resin, urethane resin, acrylic resin, polyvinyl alcohol, styrene-acrylic resin, polyvinylpyrrolidone, and acrylic-urethane copolymer. And polyethyleneimine. Among these, a polyester resin, a polyurethane resin, or a mixture thereof is preferable.

  The resin added to the inkjet ink composition of the present invention is not particularly limited as long as it is water-insoluble. For example, resin fine particles such as dispersions and emulsions are preferable. In the case of resin fine particles, the particle size is preferably 1 μm or less, and more preferably 0.5 μm or less. If the particle size is large, the nozzle of the head tends to be clogged, which greatly affects the discharge performance. The acid value of the resin is preferably 100 or less, more preferably 50 or less. If the acid value is high, the water resistance may be insufficient. The weight average molecular weight of the resin is preferably 7000 to 300,000, and more preferably 10,000 to 200,000. If the weight average molecular weight of the resin is large, the ejection properties tend to be unstable.

  Examples of commercially available water-insoluble resins that can be added to the ink-jet ink composition of the present invention include urethane resins such as hydran series (DIC) such as hydran AP-20, AP-30F, AP-40F, and WLS-213. UCOTUX UX-150, UX-200, UX-310, UWS-145, etc. UCOAT series (manufactured by Sanyo Kasei Co., Ltd.), Acryt WBR-2018, WBR-016U, WEM-3008, etc. Fine Chemicals), PTG-RSN (DIC Graphics), etc. are mentioned. Examples of the vinyl-modified epoxy ester resin include water sol series (manufactured by DIC) such as water sol EFD-5530, EFD-5570, and EFD-5580. Examples of acrylic resins include Boncoat series such as Boncoat CP-6450, CP-6280, WCW-327, and WE-300 (manufactured by DIC), and Johncrill series such as Johncrill 450, 711, 7370, and 7600 (manufactured by BASF). ) And the like. Examples of the styrene / acrylic resin include high loss series (manufactured by Seiko PMC) such as high loss X-436 and J-140A. Examples of the vinyl chloride / acrylic copolymer resins include Vinibrand series (manufactured by Nissin Chemical Industry Co., Ltd.) and the like. Examples of the polyolefin-based resin include Supercron series (manufactured by Nippon Paper Chemical Co., Ltd.) such as Supercron E-604 and S-4719. Examples of the polyester resin include Elitel series such as Elitel KA-5071S, KT-8701, and KT-9204 (manufactured by Unitika), and Bironal series such as Bironal MD-1480 and ST-6820 (made by Toyobo Co., Ltd.). It is done. Examples of polyethyleneimine include Epomin series (manufactured by Nippon Shokubai Co., Ltd.) such as Epomin SP-003, SP-006, SP-012, and SP-018.

  The content of the water-insoluble resin (solid content) in the inkjet ink composition of the present invention is sufficient for the desensitizer layer formed by recording with the inkjet printer using the inkjet ink composition. It may be a concentration having water resistance, and can be appropriately determined in consideration of the type of water-insoluble resin, desired product characteristics of carbonless copying paper, and the like.

  When the content of the water-insoluble resin (solid content) is too small, the water resistance of the formed desensitizer layer tends to be insufficient. For example, the content of the water-insoluble resin (solid content) in the inkjet ink composition of the present invention is preferably 0.1% by mass or more, more preferably 1% by mass or more, and 3% by mass. % Or more is more preferable. On the other hand, when there is too much content of water-insoluble resin (solid content), there exists a tendency for an inkjet discharge characteristic to fall. For this reason, for example, the content of the water-insoluble resin (solid content) in the inkjet ink composition of the present invention is preferably 20% by mass or less, and more preferably 15% by mass or less.

  In the inkjet ink composition of the present invention, a water-soluble organic solvent may be added in addition to the water-soluble organic desensitizer. Water-soluble organic solvents are commonly used in inkjet inks to adjust viscosity and prevent drying of the ink, to improve permeability to the recording medium, and to adjust the dot diameter on the recording medium. Functions as a penetrant added to

  In the case of using a water-soluble organic desensitizer such as polyethylene glycol, triethylene glycol monobutyl ether, polypropylene glycol, triethanolamine, or the like conventionally blended as a wetting agent in an inkjet ink, In addition, there are cases where physical properties suitable as an ink-jet ink composition can be realized without blending a water-soluble organic solvent. For this reason, the inkjet ink composition of the present invention may not contain a water-soluble organic solvent.

  In the present invention and the present specification, the “water-soluble organic solvent” does not include a water-soluble organic desensitizer. That is, the “water-soluble organic solvent” is composed of a water-soluble organic compound that does not have a desensitizing action.

  As the water-soluble organic solvent used in the ink-jet ink composition of the present invention, among the known water-soluble organic solvents not having a desensitizing action, the type of water-soluble organic solvent to be used and the ink-jet ink composition obtained are obtained. It can be appropriately selected and used in consideration of properties such as the viscosity of the object. Moreover, the ink composition for inkjet of this invention may contain one type of water-soluble organic solvent, and may contain two or more types of water-soluble organic solvents.

Specifically, as the water-soluble organic solvent, for example,
Methanol, ethanol, 1-propanol, 2-propanol, 2-methyl-1-propanol, 1-butanol, 2-butanol, pentyl alcohol, 2-methoxyethanol, 2-butoxyethanol, 2- (2-methoxyethoxy) ethanol 2- (2-butoxyethoxy) ethanol, 2- [2- (2-methoxyethoxy) ethoxy] ethanol, 2- [2- (2-butoxyethoxy) ethoxy] ethanol, 1-methyl-1-methoxybutanol, etc. Alcohols;
2-ethanediol, 1,2-propanediol, 1,3-propanediol, 1,2-butanediol, 1,3-propanediol, 1,4-butanediol, 2,3-butanediol, 1,2, -Pentanediol, 1,5-pentanediol, 1,2-hexanediol, 1,6-hexanediol, 2,2'-oxybisethanol, 2,2'-ethylenedioxybis (ethanol), thiodiethanol, Polyhydric alcohols such as glycerin, 1,2,6-hexanetriol, ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol, propylene glycol, dipropylene glycol, trimethylolpropane, pentaerythritol;
Ketones such as acetone, methyl ethyl ketone, methyl n-butyl ketone, methyl isobutyl ketone;
Tetrahydrofuran, 1,4-dioxane, 1,2-dimethoxyethane, 1,2-diethoxyethane, 2,2′-oxybis (2-methoxyethane), 2,2′-oxybis (2-ethoxyethane), 2 Ethers such as 2,2′-ethylenedioxybis (2-methoxyethane) and 2,2′-ethylenedioxybis (2-methoxyethane);
Glycol esters such as propylene glycol laurate;
Ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-iso-propyl ether, ethylene glycol mono-n-butyl ether, ethylene glycol mono-iso-butyl ether, ethylene glycol mono-tert-butyl ether, diethylene glycol monomethyl ether, diethylene glycol mono Ethyl ether, diethylene glycol mono-n-propyl ether, diethylene glycol mono-iso-propyl ether (diethylene glycol ethyl methyl ether), diethylene glycol mono-n-butyl ether, diethylene glycol mono-tert-butyl ether, diethylene glycol monohexyl ether, triethylene glycol monomethyl ether Ter, triethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol mono-n-propyl ether, propylene glycol mono-iso-propyl ether, propylene glycol mono-n-butyl ether, propylene glycol mono- tert-butyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol mono-n-propyl ether, dipropylene glycol mono-iso-propyl ether, dipropylene glycol mono-n-butyl ether, dipropylene glycol Glycol ethers such as mono-tert-butyl ether;
Alkylene oxide adducts of alkyl alcohols such as ethylene oxide hexyl ether and ethylene glycol butyl ether ethylene oxide adducts and propylene glycol propyl ether propylene oxide adducts;
Amides such as dimethylformamide, dimethylacetamide, N-methyl-pyrrolidone, 1,3-dimethyl-2-imidazolidinone;
Alcohol amines such as methyldiethanolamine;
Lactones such as γ-butyrolactone;
Sulfones such as sulfolane and dimethyl sulfoxide;
Lactams such as 2-pyrrolidone, N-methyl-2-pyrrolidone, ε-caprolactam, N- (2-hydroxyethyl) pyrrolidone;
1,3-dimethylimidazolidinone and the like can be mentioned.

  The water-soluble organic solvent contained in the ink-jet ink composition of the present invention is selected from the group consisting of alcohols, polyhydric alcohols, ketones, ethers, esters, and glycol ethers or It is preferably two or more, more preferably one or more selected from the group consisting of alcohols, polyhydric alcohols, and glycol ethers, consisting of ethanol and diethylene glycol ethyl methyl ether. It is especially preferable that it is 1 type, or 2 or more types selected from the group.

  The content of the water-soluble organic solvent in the ink-jet ink composition of the present invention can be appropriately determined in consideration of the type of water-soluble organic desensitizer used, the characteristics of the ink-jet ink composition obtained, and the like. . For example, when alcohols or glycol ethers are used as the water-soluble organic solvent, the content of alcohols or glycol ethers in the inkjet ink composition of the present invention is preferably 0 to 10% by mass.

  The water used in the present invention is not particularly specified in properties, but preferably has few impurities and does not adversely affect the quality of the inkjet ink composition. As such water, industrially known and commonly used water such as Japanese Pharmacopoeia purified water, ion exchange water, distilled water and pure water is preferable. For example, the water content in the inkjet ink composition of the present invention can be 5 to 90 masses.

  The viscosity of the inkjet ink composition of the present invention is not particularly limited as long as it is within the range required for inkjet, and can be set to 1 to 100 mPa · s, for example.

  One or more surfactants can be added to the ink-jet ink composition of the present invention in order to adjust ink properties such as surface tension, as long as the effects of the present invention are not impaired. The surfactant that can be added for this purpose is not particularly limited, and examples thereof include various anionic surfactants, nonionic surfactants, cationic surfactants, and amphoteric surfactants. In the present invention, it is preferable to use one or more selected from the group consisting of an anionic surfactant and a nonionic surfactant.

  Examples of the anionic surfactant include alkylbenzene sulfonate, alkylphenyl sulfonate, alkylnaphthalene sulfonate, higher fatty acid salt, alkyl sulfate ester salt, alkyl sulfonate ester salt, sulfate ester salt of higher alcohol ether and Examples thereof include sulfonates, higher alkyl sulfosuccinates, polyoxyethylene alkyl ether carboxylates, polyoxyethylene alkyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, and the like. In the present invention, among others, higher fatty acid salt, alkyl sulfate ester salt, alkylbenzene sulfonate, alkyl naphthalene sulfonate, dialkyl sulfosuccinate, alkyl phosphate ester salt, naphthalene sulfonate formalin condensate, or polyoxyethylene alkyl Sulfuric acid ester salts are preferred.

  Nonionic surfactants include, for example, polyoxyethylene alkyl ether, polyoxyethylene alkylphenyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene sorbitol fatty acid ester, glycerin fatty acid ester , Polyoxyethylene glycerin fatty acid ester, polyglycerin fatty acid ester, sucrose fatty acid ester, polyoxyethylene alkylamine, polyoxyethylene fatty acid amide, fatty acid alkylolamide, alkyl alkanolamide, acetylene glycol, oxyethylene adduct of acetylene glycol, Oxyethyleneoxypropylene block copolymer, polyethylene glycol polypropylene glycol Like the Lumpur block copolymer and the like. In the present invention, among others, polyoxyethylene alkyl ether, polyoxyethylene alkyl allyl ether, polyoxyethylene fatty acid ester, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, polyoxyethylene alkylamine, glycerin fatty acid ester, or oxyethylene Oxypropylene block copolymers are preferred. In addition, SURFYNOLS (manufactured by Air Products & Chemicals), which is an acetylene-based polyoxyethylene oxide surfactant, can also be used.

  The amphoteric surfactant may be a betaine type surfactant or an amine oxide type surfactant. Examples of the amine oxide surfactant include N, N-dimethyl-N-alkylamine oxide.

  Other surfactants include silicone surfactants such as polysiloxane oxyethylene adducts; fluorine surfactants such as perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and oxyethylene perfluoroalkyl ethers. Biosurfactants such as spicrispolic acid, rhamnolipid, lysolecithin and the like can also be used. These surfactants can be used alone or in combination of two or more. In consideration of the dissolution stability of the surfactant, the HLB is preferably in the range of 7-20.

  When the surfactant is added, the addition amount is preferably in the range of 0.001 to 2% by mass, more preferably 0.001 to 1.5% by mass, based on the total mass of the ink. More preferably, it is in the range of 01 to 1.0% by mass. When the addition amount of the surfactant is less than 0.001% by mass, the effect of adding the surfactant tends to be not obtained, and when it exceeds 2% by mass, problems such as blurring of the image are likely to occur. .

  In addition, various additives for imparting characteristics suitable for inkjet applications can be added to the inkjet ink composition of the present invention as long as the effects of the present invention are not impaired. Examples of such additives include pH adjusters, preservatives and fungicides, chelating agents, plasticizers, antioxidants, and ultraviolet absorbers.

  As the pH adjuster added to the ink-jet ink composition of the present invention, an organic base, an inorganic alkali, or the like can be used as a basic one, and an organic acid, an inorganic acid, or the like can be used as an acidic one. Examples of the organic base include triethanolamine, diethanolamine, N-methyldiethanolamine, and dimethylethanolamine. Examples of the inorganic alkali include sodium hydroxide, lithium hydroxide, potassium hydroxide, sodium carbonate, sodium hydrogen carbonate, ammonium and the like. Examples of the organic acid include acetic acid, propionic acid, trifluoroacetic acid, and alkylsulfonic acid. Examples of the inorganic acid include hydrochloric acid, sulfuric acid, phosphoric acid and the like. For the purpose of improving the storage stability of the inkjet ink composition, the pH adjuster is preferably added so that the pH of the inkjet ink composition is 4 to 10, and is added so that the pH is 5 to 9. More preferably.

  Examples of the preservative and fungicide added to the inkjet ink composition of the present invention include sodium benzoate, sodium pentachlorophenol, sodium 2-pyridinethiol-1-oxide, sodium sorbate, and sodium dehydroacetate. 1,2-dibenzthiazolin-3-one and the like. These compounds are commercially available, for example, as proxel CRL, proxel BND, proxel GXL, proxel GXL (S), proxel XL-2, proxel TN (all manufactured by Arch Chemicals Japan).

  The ink-jet ink composition of the present invention may contain a colorant or may not contain a colorant. For example, when a light-colored dye or the like is included as a colorant, the formed desensitizer layer is lightly colored. Therefore, the color density of the desensitizer layer is reduced by the water-solubility in the desensitizer layer. It can be used to control the concentration of organic desensitizers, and the position of the desensitizer layer can be clarified. Further, the shade of the color of the desensitizer layer can be utilized for the concentration management of the water-soluble organic desensitizer in the desensitizer layer, and further, an effect equivalent to universal design can be obtained. The colorant added to the ink-jet ink composition of the present invention is not particularly limited as long as it does not impair the desensitization effect of the water-soluble organic desensitizer and the ink jet discharge characteristics. It can be appropriately selected from known colorants blended in ink jet inks.

  The ink composition for inkjet according to the present invention may contain a fluorescent brightening agent. For example, when a fluorescent brightening agent is included, purple to blue (fluorescence) appears by applying black light to the formed desensitizer layer. The presence or absence of the expression of purple to blue can be utilized for application management. The fluorescent whitening agent contained in the inkjet ink composition of the present invention is preferably a water-soluble one or an aqueous solution previously dissolved in water. Examples of commercially available fluorescent brighteners having such characteristics include KAYAPHOR series (manufactured by Nippon Kayaku Co., Ltd.) such as KAYAPHOR FB CONC, AS150, ES LIQUID, HBC LIQUID, STC LIQUID, and the like.

  The ink-jet ink composition of the present invention is obtained by stirring and thoroughly mixing a water-soluble organic desensitizer, a water-insoluble resin, water, and other components such as a water-soluble organic solvent as necessary. It is obtained by removing impurities by filtration or the like. In addition, you may stir and mix each component, heating.

  The inkjet ink composition of the present invention can be suitably used as an inkjet recording ink. The ink jet method to be applied is not particularly limited, but examples of known ones such as a continuous jet type (charge control type, spray type, etc.), on-demand type (piezo type, thermal type, electrostatic suction type, etc.) can do.

  By printing the ink-jet ink composition of the present invention on a recording material such as paper using an ink-jet printer, a desensitizer layer of carbonless copying paper can be formed. The carbonless copy paper provided with the desensitizer layer formed in this way can prevent copying due to normal writing pressure or printing pressure.

  EXAMPLES Hereinafter, although this invention is shown concretely using an Example, this invention is not limited to a following example etc. In these examples, “part” means mass part, and “%” means mass percent.

Of the raw materials used in the following Examples and the like, PTG-RSN (manufactured by DIC Graphics) is a polyurethane resin (resin solid content: 35%, weight average molecular weight: 19000), and Eritel KT-8701 (Unitika). Is a polyester resin emulsion (resin solid content: 30%, weight average molecular weight: 13000), and Joncryl 57J (BASF) is a water-soluble resin (nonvolatile content: 37%, acid value: 215, weight average). Joncrill PDX-7630A (manufactured by BASF) is resin fine particles of emulsion (nonvolatile content: 32%, acid value: 200, weight average molecular weight:> 200,000), and Joncrill PDX-6102B (BASF) is a water-soluble resin (nonvolatile content: 24.5%, acid value: 65, weight average molecular weight: 60000) Yes, Hydran AP-40F (manufactured by DIC) is a urethane-based resin (nonvolatile content: 22.5%, acid value: 25, weight average molecular weight: 40000), and Hydran AP-30F (manufactured by DIC) is urethane-based. Resin (nonvolatile content: 20%, acid value: 25, weight average molecular weight: 50000).
Surfynol 440 (Air Products & Chemicals, Nonionic), Orphine E1010 (Shin-Etsu Chemical Co., Nonionic), MegaFuck F-444 (DIC, Nonionic), and BYK-348 (Bic Chemie, Nonionic) is a surfactant.
“Desensitizer A” is an amine derivative (manufactured by San Nopco), and Proxel GXL (S) (manufactured by Arch Chemicals Japan) is a preservative.

[Examples 1 to 12, Comparative Examples 1 to 5]
First, ink jet ink compositions were obtained according to the compositions shown in Tables 1 to 3. Specifically, after all the raw materials other than water were blended and stirred, water was added and dissolved by stirring and mixing while heating at 40 ° C. After dissolution, in order to remove impurities such as dust, it was filtered with a syringe filter having a pore diameter of 0.5 μm.

The obtained ink composition for inkjet was evaluated for desensitization, water resistance, and inkjet (IJ) discharge performance in three stages (◯: good, Δ: normal, x: inferior). Each evaluation standard is shown below.
Solubility evaluation: The state after dissolution was visually determined.
Dryability evaluation: After applying a desensitizing solution to a lower paper having a developer layer on the surface with a bar coater, the dried state and the curled state of the paper were dried for 1 minute at a temperature of 80 ° C. Judgment was made visually.
Desensitization evaluation: A desensitizing solution is applied to a lower paper having a developer layer on the surface with a bar coater and dried, and then an upper paper having a microcapsule layer containing a color former is placed on the back. The desensitization (presence / absence of color development) was visually judged by the writing pressure.
Water resistance evaluation: The sample used for the desensitization evaluation was immersed in water, and the desensitization (presence or absence of color development) was visually judged.
IJ dischargeability evaluation: EB-100 (IJ head) manufactured by Konica Minolta IJ was filled with a desensitizing solution, and the printed state of what was printed on IJ paper was visually judged.

The evaluation results of each ink-jet ink composition are shown in Tables 1 to 3. In the table, “-” indicates that evaluation was not performed. As a result, the inkjet ink compositions of Examples 1 to 12 containing 25 to 35% of polyethylene glycol or triethylene glycol monobutyl ether having a number average molecular weight of 600 and containing a polyester resin or a polyurethane resin were reduced. Sensitivity, water resistance, and IJ ejection properties were all good.
On the other hand, the inkjet ink composition of Comparative Example 1 or 2 containing 10% of polyethylene glycol or triethylene glycol monobutyl ether had insufficient desensitization. This is presumably because the content of these water-soluble organic desensitizers was too small. Further, the ink compositions for inkjets of Comparative Examples 3 to 5 containing 30% of glycerin, diethylene glycol, or triethylene glycol are not desensitized or insufficient, and these water-soluble organic compounds are sufficient. It has been found that it is not a water-soluble organic desensitizer. Furthermore, since the inkjet ink compositions of Comparative Examples 1 to 5 did not contain any water-insoluble resin, they were inferior in water resistance.

[Examples 13 to 58, Comparative Examples 6 to 22]
The inkjet ink composition of the present invention was produced using polyethylene glycol or triethylene glycol monobutyl ether having a number average molecular weight of 200, 400, 600, or 10,000 as the water-soluble organic desensitizer.
First, ink jet ink compositions were obtained according to the compositions shown in Tables 4 to 13. Specifically, after all the raw materials other than water were blended and stirred, water was added and dissolved by stirring and mixing while heating at 40 ° C. After dissolution, in order to remove impurities such as dust, it was filtered with a syringe filter having a pore diameter of 0.5 μm.

  The solubility, desensitization, water resistance, and inkjet (IJ) ejection properties of the obtained inkjet ink composition were evaluated in three stages (◯: good, Δ: normal, x: inferior). The evaluation criteria for solubility evaluation are shown below. The solubility evaluation, drying evaluation, desensitization evaluation, water resistance evaluation, and IJ dischargeability evaluation were performed in the same manner as in Example 1 and the like.

  The evaluation results of each ink-jet ink composition are shown in Tables 4 to 13. In the table, “-” indicates that evaluation was not performed. As a result, 20 to 40% of polyethylene glycol or triethylene glycol monobutyl ether having a number average molecular weight of 400, 600 or 10,000 was contained, and polyester resin or polyurethane resin was contained in an amount of 3 to 3.5% in solid content. Examples 14 to 17, 20 to 23, 26 to 29, 32, 35, 38, 40 to 43, 45, 48, 51, and 55, the ink-jet ink compositions were obtained by adding ethanol or diethylene glycol ethyl methyl ether, Regardless of the type of surfactant added and whether or not it was used in combination, all of solubility, desensitization, water resistance, and IJ ejection properties were good. Also, an ink-jet ink composition of Example 50 in which polyethylene glycol having a number average molecular weight of 600 and triethylene glycol monobutyl ether were added together, or a polyethylene glycol having a number average molecular weight of 400 and a polyethylene glycol having a number average molecular weight of 600 were used in combination. The ink compositions for ink jets of Examples 52 to 54 and 56 to 58 that were added also had good solubility, desensitization, water resistance, and IJ ejection properties regardless of whether or not a surfactant was added. .

On the other hand, the ink-jet ink compositions of Examples 13, 19, 25, 31, 34, and 37 containing 15% of polyethylene glycol or triethylene glycol monobutyl ether having a number average molecular weight of 600 or 10,000 are water-soluble. Although it was slightly inferior to the ink composition for ink jet containing 20% or more of the reactive organic desensitizer, it had sufficient desensitization and water resistance. In addition, the solubility and IJ discharge property of these ink-jet ink compositions were good.
Further, the ink-jet ink composition of Example 47 containing 30% polyethylene glycol having a number average molecular weight of 200 is slightly more than the ink-jet ink composition containing polyethylene glycol having a number average molecular weight of 600 or 10,000. Although inferior, it had sufficient desensitization and water resistance. In addition, the solubility and IJ discharge property of this ink-jet ink composition were good.

Also, the ink-jet ink compositions of Examples 18, 24, 30, 33, 36, and 39 containing 45% of polyethylene glycol or triethylene glycol monobutyl ether having a number average molecular weight of 600 or 10000 have solubility, reduced Both sensitivity and water resistance were good. The IJ ejection performance was also sufficient as an inkjet ink composition, although it was slightly inferior to the inkjet ink composition containing 40% or less of these water-soluble organic desensitizers.
The ink-jet ink compositions of Examples 44, 46 and 49 containing 10 or 15% polyester resin or polyurethane resin are ink-jet inks containing 3 to 3.5% of these water-insoluble resins in solid content. Although it was slightly inferior to the composition, it had sufficient IJ ejection properties. In addition, the solubility, desensitization, and water resistance of these ink-jet ink compositions were good.

On the other hand, Comparative Examples 6 to 10 in which the water-insoluble resin was not added had good solubility and desensitization regardless of the presence or absence of addition of ethanol or surfactant, but poor water resistance. It was.
Moreover, it replaces with the inkjet ink composition of Comparative Examples 11 and 13 which does not contain polyethyleneglycol or triethyleneglycol monobutyl ether, and these water-soluble organic desensitizers, and contains glycerin, diethylene glycol, or triethylene glycol The inkjet ink compositions of Comparative Examples 15 to 17 were not desensitized.
The inkjet ink compositions of Comparative Examples 12 and 14 containing 50% polyethylene glycol or triethylene glycol monobutyl ether were all good in solubility, desensitization, and water resistance, but poor in drying properties. The ink composition was unsuitable.
The inkjet ink compositions of Comparative Examples 18 and 19 to which the desensitizer A blended in the desensitizing ink for offset printing was added had poor solubility and were unsuitable as an inkjet ink composition.
Furthermore, in the inkjet ink compositions of Comparative Examples 20 to 22 using a water-soluble resin, the solubility, drying property, and desensitization were good, but the water resistance was insufficient.

[Examples 59 to 74]
The inkjet ink composition of the present invention was produced using polyethylene glycol having a number average molecular weight of 400 or 600 as a water-soluble organic desensitizer.
First, according to the compositions shown in Tables 14 to 16, ink jet ink compositions were obtained in the same manner as in Example 13 and the like.
The solubility, desensitization, water resistance, and inkjet (IJ) ejection properties of the obtained inkjet ink composition were evaluated in three stages (◯: good, Δ: normal, x: inferior). The evaluation criteria for solubility evaluation are shown below. The solubility evaluation, drying evaluation, desensitization evaluation, water resistance evaluation, and IJ dischargeability evaluation were performed in the same manner as in Example 1 and the like. The evaluation results are shown in Tables 14-16. Regardless of the type and content of the resin to be added, all of the inkjet ink compositions of Examples 59 to 74 had good solubility, drying property, desensitization property, water resistance, and IJ ejection property. .

  The ink-jet ink composition of the present invention can form a desensitizer layer for carbonless copying paper by the ink jet recording method, and can therefore be widely applied to the production of carbonless copying paper.

Claims (7)

Contains a water-soluble organic desensitizer, a water-insoluble resin, and water,
The inkjet ink composition, wherein the content of the water-soluble organic desensitizer is 15 to 45% by mass.   2. The water-soluble organic desensitizer is one or more selected from the group consisting of polyethylene glycol, triethylene glycol monobutyl ether, monoethanolamine, diethanolamine, triethanolamine, and polypropylene glycol. 2. An ink composition for inkjet according to the above.   Furthermore, the ink composition for inkjets of Claim 1 or 2 containing a water-soluble organic solvent.   The water-soluble organic solvent is one or more selected from the group consisting of alcohols, polyhydric alcohols, ketones, ethers, esters, and glycol ethers. Ink-jet ink composition.   The water-soluble organic desensitizer is one or more selected from the group consisting of polyethylene glycol and triethylene glycol monobutyl ether, and the water-soluble organic solvent is selected from the group consisting of ethanol and diethylene glycol ethyl methyl ether. The ink composition for ink jet according to claim 3, wherein the ink composition is one or more selected.   The water-insoluble resin is one or more selected from the group consisting of polyester resin, urethane resin, acrylic resin, polyvinyl alcohol, styrene-acrylic resin, polyvinylpyrrolidone, acrylic-urethane copolymer, and polyethyleneimine. The inkjet ink composition according to any one of claims 1 to 5.   A recorded matter recorded by an ink jet recording method using the ink composition for ink jet according to any one of claims 1 to 6.