JP2008291072A - Ink composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an information carrying sheet on which an information pattern can be accurately detected in a near-infrared wavelength region and which is useful to ascertain whether securities are true, and an ink composition having absorption in a near-infrared wavelength region and useful to form the information pattern. <P>SOLUTION: The ink composition contains a near-infrared absorbing material which is a special sulfur-metal complex compound. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an ink composition having absorption in the near infrared wavelength region. More specifically, the present invention can accurately detect an information pattern in the near-infrared wavelength region, and is useful for forming an information carrying sheet useful for discriminating the authenticity of securities and the like, and an ink composition useful for forming the information pattern. About things.

  Conventionally, various functions have been applied to various certificates to prevent falsification and counterfeiting. For example, a function to prevent identification and tampering by applying liquid crystal, conductive material, and magnetic material that can be identified only by specific operations so that they cannot be identified with the naked eye under normal conditions. Is granted. These methods are, for example, insufficient in the effect of visual recognition under normal conditions with the naked eye, easy to peel off, damage or falsify during use, or cannot be easily collated. It was not always satisfactory.

  In recent years, a detection method using infrared absorption has been used as a relatively easy method, and has also been applied to barcode printing. For example, an information pattern is printed on a predetermined portion such as securities using a printing ink containing an infrared absorbing material such as carbon black, and the presence / absence of the information pattern is read by an infrared reading device to determine authenticity. However, since the carbon black has light absorptivity even in the visible light region, the presence or absence of an information pattern can be visually determined. For this reason, even if the information pattern is formed, it is identified, and the accuracy of authenticity determination is lowered.

  In general, as infrared absorbers, acetylacetone metal chelate compounds, anthraquinone compounds, naphthoquinone compounds, diamine cisethylenethiolatonickel derivatives, aromatic diamine metal complexes, aliphatic diamine metal complexes, aromatic dithiol metal complexes, aliphatic dithiols Metal complexes and the like are known. Patent Document 1 discloses a machine-readable information carrying sheet in which an information pattern is printed with a white infrared reflective ink on an information carrying sheet medium containing an infrared absorbing substance in a sheet-like substrate. Patent Document 2 discloses a surface having infrared reflectivity and an infrared absorptivity having the same color as this surface and containing divalent iron ions and / or divalent copper ions and phosphate white crystal powder. A mechanically readable information carrying sheet with a printing ink layer is disclosed. Patent Document 3 and Patent Document 4 disclose a machine-readable information-carrying sheet having an information pattern formed of an ultraviolet-curable infrared absorbing ink containing an infrared absorbing material on an infrared reflective substrate. ing.

  These inks are obtained by dispersing powder that is an infrared reflecting or absorbing substance, and there may be variations in information reading depending on the degree of dispersion. The infrared reflecting or absorbing material used in the ink has a low solubility in the solvent used in the ink and a low compatibility with the vehicle, so that the dispersion state tends to deteriorate. When the dispersion is deteriorated, not only the stability as an ink is lost, but also the problem that the infrared reflection or absorption substance cannot be uniformly present in the film and the sensitivity in reading information is lowered. In addition, the transparency of the coating film is low, and there are some that are colored, which may be visually confirmed. In recent years, there has been an increasing number of cases in which information patterns and dot patterns are required to be made finer or thinner, and a film that forms a sharpness of the pattern outline and forms a pattern by finely dispersing or dissolving infrared reflective or absorbing substances. The need for uniform thickness and improved pattern accuracy is increasing.

  In the case of offset ink, if there is a substance with a particle size of 10μm or more in the vehicle, transfer failure will occur, the plate will be damaged, and these substances will be deposited on the plate or blanket during printing, making it impossible to print. However, these materials are poorly dispersible in the lithographic ink vehicle and cannot exist as particles of 10 μm or less in the ink vehicle, and cause aggregation in the vehicle. Cannot be used. In addition, these materials lack the heat resistance, light resistance, and chemical resistance necessary for printing inks.

In the toner for developing an electrostatic image, it is disclosed that a croconium dye that is an infrared absorber is used for forming an invisible pattern.
JP-A-6-191137 JP-A-6-247087 Japanese Patent Laid-Open No. 7-68982 JP 2003-326879 A JP 2002-146254 A

  The present invention has a solubility in a solvent, a stability including a near-infrared absorbing material having high compatibility with an ink vehicle, good dispersibility, no aggregation over time in the vehicle, heat resistance, light resistance, chemical resistance It is an object of the present invention to provide an ink composition that can be detected with high sensitivity by a near-infrared sensor excellent in. Another object of the present invention is to provide an information-carrying sheet that is difficult to identify visually and is useful for preventing forgery and alteration, and an ink composition useful for obtaining this sheet. To do. Another object of the present invention is to provide an ink composition capable of forming an information pattern that has been refined and thinned.

    1st invention is an ink composition characterized by including the near-infrared absorption material which has a repeating unit represented by following General formula (1).

  General formula (1):

(In the formula, M represents a metal atom, any one of R ^{1 to} R ²⁰ represents a direct bond, the other represents a divalent group represented by the following general formula (2), and the rest Each independently represents a hydrogen atom or a substituent.)
General formula (2):

(In the formula, X ^{1 to} X ⁴ are a direct bond or —NHCO—, —CONH—, —NHCOO—, —OCONH—, —O—, —S—, —COO—, —OCO—, —SO ₂ —, — CO—, —C═C—, —N═N—, —SS—, represents a substituted or unsubstituted imino group, Ar ¹ and Ar ² represent a direct bond or a substituted or unsubstituted arylene group or a substituted or unsubstituted Represents an unsubstituted heteroarylene group, n represents a natural number, Y represents a direct bond or an unsubstituted alkylene group, —NHCO—, —CONH—, —NHCOO—, —OCONH—, —O—, —S—, —NH—, —COO—, —OCO—, —SO ₂ —, —CO—, —C═C—, —N═N—, —SS—, a substituted imino group or the following divalent organic residue Represents.)

In the second invention, any one of R ^{1 to} R ¹⁰ of the near-infrared absorbing material is a direct bond, and any one of R ^{11 to} R ²⁰ is represented by the general formula (2). The ink composition according to the first invention, wherein the ink composition is a valent group.

In the third invention, any one of R ^{1 to} R ⁵ of the near-infrared absorbing material is a direct bond, and any one of R ^{6 to} R ¹⁰ is a divalent group represented by the general formula (2). It is an ink composition according to the first aspect of the invention.

According to a fourth invention, in the near-infrared absorbing material, any one of R ^{1 to} R ⁵ is a direct bond, and the other one of R ^{1 to} R ⁵ is a divalent group represented by the general formula (2). The ink composition according to the first aspect of the invention.

  A fifth invention is the ink composition according to any one of the first to fourth inventions, wherein the near-infrared absorbing material is a homopolymer having a repeating unit represented by the general formula (1).

  6th invention is a copolymer in which a near-infrared absorptive material is a copolymer which has 2 or more types of the repeating unit represented by General formula (1) as a repeating unit, Any one of the 1st-4th invention characterized by the above-mentioned. It is an ink composition.

  A seventh invention is any one of the first to sixth inventions characterized in that the benzene ring to which the divalent group represented by the general formula (2) is not bonded has a substituent at the ortho position of the near-infrared absorbing material. Or an ink composition as described above.

  An eighth invention is the ink composition according to any one of the first to seventh inventions, wherein the ink composition is a lithographic ink.

  A ninth invention is the ink composition according to any one of the first to seventh inventions, wherein the ink composition is an electrostatic image developing toner.

  A tenth invention is the ink composition according to any one of the first to seventh inventions, wherein the ink composition is an ink jet ink.

  An eleventh invention is the ink composition according to any one of the first to seventh inventions, wherein the ink composition is a gravure ink.

  The ink composition of the present invention includes a near-infrared absorbing material having high solubility in a solvent, ink vehicle, and binder resin, so that the dispersibility and stability are good, and the toner charging property is uniform and stable. In addition, it was possible to provide an ink composition that is free from background stains and can be detected with high sensitivity by a near infrared sensor. Furthermore, the coating film using the said ink composition was highly transparent, was hardly seen coloring, and was able to provide the ink composition which cannot be confirmed visually.

  The novel near-infrared absorbing material of the present invention will be specifically described below. General formula (1) which is the near-infrared absorbing material of the present invention:

In the polymer having the repeating unit represented by the formula, M represents a metal atom, any one of R ^{1 to} R ²⁰ represents a direct bond, and the other represents the general formula (2):

And the rest each independently represents a hydrogen atom or a substituent.

  The metal atom of M in the general formula (1) is not particularly limited as long as it is a metal atom, but nickel, cobalt, platinum, palladium, or copper is preferable, and nickel is more preferable.

In addition, examples of the substituent for R ^{1 to} R ²⁰ include a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group, a substituted or unsubstituted group. Thioalkoxy group, cyano group, amino group, mono- or di-substituted amino group, hydroxyl group, mercapto group, substituted or unsubstituted aryloxy group, substituted or unsubstituted arylthio group, substituted or unsubstituted aryl group, substituted or unsubstituted It represents a substituted heteroaryl group, and the substituents may form a conjugated or non-conjugated ring with substitution or unsubstituted substitution between adjacent substituents. Preferred examples of the substituent include a halogen atom, an alkyl group having 1 to 20 carbon atoms, an alkoxy group, and a mono- or di-substituted amino group. In addition, examples of the conjugated or non-conjugated ring that is substituted or unsubstituted between adjacent substituents include, for example, 5- to 7-membered oxygen, nitrogen, and sulfur atoms between adjacent substituents. Aliphatic, carbocyclic aromatic, heterocyclic aromatic, and heterocyclic ring may be mentioned, and these rings may further have a substituent at any position. Hereinafter, these groups will be described in more detail.

The substituted or unsubstituted alkyl group constituting the R ^{1 to} R ²⁰ substituents is not particularly limited as long as it is a substituted or unsubstituted alkyl group. The alkyl group may be linear, branched or cyclized cycloalkyl group. Specific examples of the substituted or unsubstituted alkyl group include a methyl group, an ethyl group, a propyl group, a butyl group, a sec-butyl group, a tert-butyl group, a pentyl group, a hexyl group, a 2-ethylhexyl group, and a heptyl group. Octyl group, isooctyl group, stearyl group, trichloromethyl group, trifluoromethyl group, cyclopropyl group, cyclohexyl group, 1,3-cyclohexadienyl group, 2-cyclopenten-1-yl group, 2,4-cyclopentadiene Examples include a -1-ylidenyl group.

Further, the substituted or unsubstituted alkoxy group constituting the substituents of R ^{1 to} R ²⁰ is not particularly limited as long as it is a substituted or unsubstituted alkoxy group. Group, propoxy group, n-butoxy group, sec-butoxy group, tert-butoxy group, pentyloxy group, hexyloxy group, 2-ethylhexyloxy group, stearyloxy group, trifluoromethoxy group and the like.

Further, the substituted or unsubstituted thioalkoxy group constituting the substituent of R ^{1 to} R ²⁰ is not particularly limited as long as it is a substituted or unsubstituted thioalkoxy group. For example, a methylthio group , Ethylthio group, propylthio group, butylthio group, sec-butylthio group, tert-butylthio group, pentylthio group, hexylthio group, heptylthio group, octylthio group and the like.

Further, the mono- or di-substituted amino group constituting the substituent of R ^{1 to} R ²⁰ is not particularly limited as long as it is a mono- or di-substituted amino group, and examples thereof include a methylamino group, a dimethylamino group, and the like. Group, ethylamino group, diethylamino group, dipropylamino group, dibutylamino group, diphenylamino group, bis (acetoxymethyl) amino group, bis (acetoxyethyl) amino group, bis (acetoxypropyl) amino group, bis (Acetoxybutyl) amino group, dibenzylamino group and the like can be mentioned.

Moreover, as a substituted or unsubstituted aryloxy group which comprises the substituent of said R < ¹ > -R < ²⁰ >, a phenoxy group, p-tert- butyl phenoxy group, 3-fluoro phenoxy group etc. are mentioned, for example.

Examples of the substituted or unsubstituted arylthio group constituting the substituents of R ^{1 to} R ²⁰ include a phenylthio group and a 3-fluorophenylthio group.

In addition, as the substituted or unsubstituted aryl group constituting the substituents of R ^{1 to} R ²⁰ ,
For example, phenyl group, biphenylenyl group, triphenylenyl group, tetraphenylenyl group, 3-nitrophenyl group, 4-methylthiophenyl group, 3,5-dicyanophenyl group, o-, m- and p-tolyl group, xylyl group, o-, m- and p-cumenyl groups, mesityl groups, pentarenyl groups, indenyl groups, naphthyl groups, anthracenyl groups, azulenyl groups, heptalenyl groups, acenaphthylenyl groups, phenalenyl groups, fluorenyl groups, anthryl groups, anthraquinonyl groups, 3-methyl Anthryl group, phenanthryl group, pyrenyl group, chrysenyl group, 2-ethyl-1-chrysenyl group, picenyl group, perylenyl group, 6-chloroperenyl group, pentaphenyl group, pentacenyl group, tetraphenylenyl group, hexaphenyl group, Hexacenyl group, rubicenyl group Coronenyl groups, trinaphthylenyl groups, heptacenyl groups, pyranthrenyl groups, ovalenyl group and the like.

Examples of the substituted or unsubstituted heteroaryl group constituting the substituent of R ^{1 to} R ²⁰ include thionyl group, furyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, pyridyl group, pyrazinyl group, pyrimidinyl group, Pyridazinyl group, indolyl group, quinolyl group, isoquinolyl group, phthalazinyl group, quinoxalinyl group, quinazolinyl group, carbazolyl group, acridinyl group, phenazinyl group, furfuryl group, isothiazolyl group, isoxazolyl group, furazanyl group, phenoxazinyl group, benzothiazolyl group, benzoxazolyl group Examples include a zolyl group, a benzimidazolyl group, a 2-methylpyridyl group, and a 3-cyanopyridyl group.

Examples of the conjugated or non-conjugated ring having a substituted or unsubstituted group formed by bonding of adjacent substituents constituting the substituents of R ^{1 to} R ²⁰ include a substituted cyclohexyl group and a naphthyl group. It is done.

On the other hand, in the general formula (2), X ^{1 to} X ⁴ are a direct bond or —NHCO—, —CONH—, —NHCOO—, —OCONH—, —O—, —S—, —COO—, —OCO—. , —SO ₂ —, —CO—, —C═C—, —N═N—, —SS—, a substituted or unsubstituted imino group, preferably an ether bond group, ester bond group, substituted or An unsubstituted imino group.

  Examples of the substituted imino group include the following.

Ar ¹ and Ar ² in the general formula (2) represent a direct bond, a substituted or unsubstituted arylene group or a substituted or unsubstituted heteroarylene group, and preferably a substituted or unsubstituted phenylene group.

The substituted or unsubstituted arylene group is preferably a monocyclic or condensed arylene group having 6 to 60 carbon atoms, more preferably an arylene group having 6 to 40 carbon atoms, and still more preferably an arylene group having 6 to 30 carbon atoms. is there. Specific examples include phenylene, biphenylene, naphthalenediyl, anthracenediyl, phenanthroline diyl, pyrenediyl, triphenylenediyl, benzophenanthroline diyl, perylenediyl, pentaphenylenediyl, pentacenediyl, and the like. Also good. Examples of these substituents include those similar to the substituents for R ^{1 to} R ²⁰ described above.

The substituted or unsubstituted heteroarylene group is preferably a monocyclic or condensed aromatic heterocyclic group having 4 to 60 carbon atoms, more preferably at least a nitrogen atom, an oxygen atom or a sulfur atom. It is a monocyclic or condensed aromatic heterocyclic group having 4 to 60 carbon atoms containing one, and more preferably a 5- or 6-membered aromatic heterocyclic group having 4 to 30 carbon atoms. Specific examples of the aromatic heterocyclic group include pyrrole diyl, furandyl, thienylene, pyridinediyl, pyridazinediyl, pyrimidinediyl, pyrazinediyl, quinolinediyl, isoquinolinediyl, cinnolinediyl, quinazolinediyl, quinoxalinediyl, phthalazinediyl, pteridinediyl, acridinediyl, Examples include phenazine diyl and phenanthroline diyl, and these groups may have a substituent. Examples of these substituents include those similar to the substituents for R ^{1 to} R ²⁰ described above.

In the general formula (2), n represents a natural number, Y represents a direct bond or an unsubstituted alkylene group, —NHCO—, —CONH—, —NHCOO—, —OCONH—, —O—, —S—, -NH -, - COO -, - OCO -, - SO 2 -, - CO -, - C = C -, - N =
N-, -SS-, a substituted imino group or the following divalent organic residue is represented. In addition, as a substituent of a substituted imino group, a linear, branched, or cyclic alkyl group is mentioned as a preferable thing.

The repeating unit evaluated by the general formula (1) is preferably (i) any one of R ^{1 to} R ¹⁰ is a direct bond, and any one of R ^{11 to} R ²⁰ is general. A repeating unit which is a divalent group represented by the formula (2), (B) any one of R ^{1 to} R ⁵ is a direct bond, and any one of R ^{6 to} R ¹⁰ is the general formula (2) A repeating unit which is a divalent group represented, (C) ^{one of} R ^{1 to} R ⁵ is a direct bond, and the other one of R ^{1 to} R ⁵ is a divalent represented by the general formula (2) Or (d) a repeating unit in which R ³ is a direct bond and any one of R ¹³ or R ¹⁸ is a divalent group represented by the general formula (2). Preferably, repeating units represented by the following general formulas (4) to (7) are mentioned.
General formula (4):

Or, general formula (5):

General formula (6):

General formula (7):

In the general formulas (4) to (7), M, R ^{1 to} R ²⁰ , X ^{1 to} X ⁴ , Ar ¹ , Ar ² , Y,
n represents the same as described in the above general formula.

  In the present invention, the compound represented by the general formula (1) is preferably added to the ink in an amount of 20% by weight or less, more preferably 1 to 15% by weight. If the addition amount exceeds 20% by weight, the ink fluidity deteriorates, which is not preferable for printing. In particular, good ink fluidity can be obtained at 1 to 15% by weight. If it is less than 1% by weight, there is a possibility that sufficient absorption for detection by an infrared sensor cannot be obtained. As the ink composition, various printing inks conventionally used can be used.

  If the ink of the present invention is at least in the form of an information pattern and difficult to distinguish from the infrared reflective surface of the substrate by visual observation, it may be colored in the visible light range, but is preferably colorless and transparent. If the color is difficult to identify, the visual identification is further difficult. Therefore, it is preferable that the ink composition is difficult to distinguish from the substrate surface not only in the form of a fine information pattern but also in color. Such an ink composition is preferably in the visible light region and has the same color (same or similar color) as the infrared reflective base material surface, or is colorless to pale. Note that the same color and light color means that it can be visually identified with the base material in color, and the hue, saturation, and / or lightness are the same or similar (or similar) to the color of the base material. ) In many cases.

  In the present invention, it is preferable to use a lithographic ink, an inkjet ink, a gravure ink or a toner as the ink in order to accurately form an information pattern of a thin film having a fine and uniform thickness.

  The lithographic ink may be an off-wheel ink or the like, but is often a sheet-fed ink. In addition, when a pattern is formed with lithographic printing ink using wetting water, if the outline is not clear, or a dot or void is formed in the dot by fine water droplets, an uneven pattern is formed, and pattern accuracy May decrease. Therefore, waterless lithographic ink is preferable in order to increase the accuracy of the information pattern. Compared with general lithographic inks that use fountain solution, waterless lithographic inks can form information patterns with a uniform thickness and sharp contours, and the contrast of the boundary area between the substrate and the information pattern can be reduced. As a result, the fine pattern can be formed thinly and uniformly with high accuracy. The lithographic ink is usually an oxidation polymerization type ink usually containing a drying oil or a semi-drying oil (unsaturated oil), but it may be an actinic ray curable ink such as an ultraviolet curable ink. .

  In the oxidation polymerization type lithographic ink, a binder resin, fats and oils, a high boiling point solvent, a dryer, a drying inhibitor, an auxiliary agent, and the like can be used depending on the type.

  More specifically, examples of the binder resin for the oxidation polymerization type lithographic ink include, for example, phenol resins (eg, rosin-modified phenol resins using rosins such as phenol resins, rosins, cured rosins, and polymerized rosins), males, and the like. An acid resin (rosin-modified maleic acid resin, rosin ester resin, etc.), an alkyd resin or a modified alkyd resin, a petroleum resin, etc. are shown, and these can be used alone or in combination of two or more.

  The oils and fats are vegetable oils and compounds derived from vegetable oils. For example, in triglycerides of glycerin and fatty acids, at least one fatty acid is a fatty acid having at least one carbon-carbon unsaturated bond, and those triglycerides. And fatty acid monoesters obtained by ester reaction of saturated or unsaturated alcohols, or fatty acid monoesters obtained by direct ester reaction of vegetable oil fatty acids and monoalcohols, and ethers.

  Typical vegetable oils are: Asa seed oil, flaxseed oil, Eno oil, Oitsika oil, olive oil, cacao oil, kapok oil, kayak oil, mustard oil, kyounin oil, tung oil, kukui oil, walnut oil, poppy oil, sesame oil , Safflower oil, Japanese radish seed oil, soybean oil, daikon oil, camellia oil, corn oil, rapeseed oil, niger oil, nuka oil, palm oil, castor oil, sunflower oil, grape seed oil, gentian oil, pine seed oil Cottonseed oil, palm oil, peanut oil, dehydrated castor oil, and the like.

  The high boiling point solvent is a crude oil-derived solvent (petroleum solvent) having an aromatic hydrocarbon content of 1% by weight or less. As the petroleum solvent, a petroleum solvent having an aniline point of 70 ° C. to 110 ° C. and a boiling point of 230 ° C. or more is suitable. When the aniline point is less than 70 ° C., the ability to dissolve the resin is too high, the ink viscosity becomes too low, and the background stain resistance becomes insufficient. Also, when the aniline point exceeds 110 ° C., the ability to dissolve the resin is too low, the ink viscosity becomes too high, the ink fluidity becomes poor, and the ink tends to deposit on the rollers, plates, and blankets. Therefore, it is not preferable.

  The dryer is an oxidative polymerization catalyst that promotes oxidative polymerization. Acetic acid, propionic acid, butyric acid, isopentanoic acid, hexanoic acid, 2-ethylbutyric acid, naphthenic acid, octylic acid, nonanoic acid, decanoic acid, 2-ethyl Hexanoic acid, isooctanoic acid, isononanoic acid, lauric acid, palmitic acid, stearic acid, oleic acid, linoleic acid, neodecanoic acid, versatic acid, secanoic acid, tall oil fatty acid, linseed oil fatty acid, soybean oil fatty acid, dimethylhexanoic acid , 3,5,5-trimethylhexanoic acid, metal salts of organic carboxylic acids such as dimethyloctanoic acid, such as calcium, cobalt, lead, iron, manganese, zinc, zirconium, salts, etc. Compounds can be used and these to promote printing ink surface and internal curing A plurality of them can be used in combination as appropriate.

  Further, the drying inhibitor is a polymerization inhibitor having an inhibitory effect on the oxidative polymerization reaction, and hydroquinone derivatives represented by hydroquinone, 2-methylhydroquinone, 2-tert-butylhydroquinone, etc. -Denotes phenolic compounds typified by tert-butyl-4-hydroxytoluene and the like, vitamin compounds having an antioxidant action typified by ascorbic acid, tocopherol, etc., and these are arbitrarily used alone or in combination of two or more. Can be used.

As auxiliary agents, anti-friction agents, anti-blocking agents, slip agents, pigment dispersants, carnauba wax, wax wax, lanolin wax, montan wax, paraffin wax, microcrystalline wax, natural wax, Fischer-Tropsch synthetic wax, Synthetic waxes such as polyethylene wax, polypropylene wax, polytetrafluoroethylene wax and polyamide wax, silicone additives, leveling agents and the like can be used as appropriate.
In the ultraviolet curable lithographic ink, a binder resin, a monomer, an oligomer, a photopolymerization initiator, an auxiliary agent, and the like can be used depending on the type.

  Examples of the binder resin for the ultraviolet curable lithographic ink include polyvinyl chloride, poly (meth) acrylic acid ester, epoxy resin, polyester resin, polyurethane resin, cellulose derivatives (for example, ethyl cellulose, cellulose acetate, nitrocellulose), vinyl chloride. -Vinyl acetate copolymer, polyamide resin, polyvinyl acetal resin, diallyl phthalate resin, alkyd resin, rosin modified alkyd resin, petroleum resin, urea resin, synthetic rubber such as butadiene-acrylonitrile copolymer, etc. They can be used alone or in combination of two or more. In either case, a resin that is soluble in a monomer having an ethylenically unsaturated double bond is used.

  Moreover, as a monomer, monofunctional or polyfunctional (meth) acrylates are mentioned, The viscosity of an ink composition can be adjusted by using these suitably.

  As the oligomer, alkyd acrylate, epoxy acrylate, urethane-modified acrylate, or the like is used.

  In addition, one or two or more photopolymerization initiators can be appropriately added to the ultraviolet curable ink as a component that promotes the curing action.

  As photopolymerization initiators, benzophenone, 4-methylbenzophenone, 4,4-diethylaminobenzophenone, diethylthioxanthone, 2-methyl-1- (4-methylthio) phenyl-2-morpholinopropan-1-one, 4-benzoyl -4′-methyldiphenyl sulfide, 1-chloro-4-propoxythioxanthone, isopropylthioxanthone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1-hydroxy-cyclohexyl-phenyl ketone, bis-2, 6-dimethoxybenzoyl-2,4,4-trimethylpentylphosphine oxide, 1- [4- (2-hydroxyethoxy) -phenyl] -2-hydroxy-2-methyl-1-propan-1-one, 2, 2-dimethyl-2-hydroxyacetate Enone, 2,2-dimethoxy-2-phenylacetophenone, 2,4,6, -trimethylbenzyl-diphenylphosphine oxide, 2-benzyl-2-dimethylamino-1- (monoforinophenyl) -butane-1- ON etc. are mentioned. A photo accelerator such as p-dimethylaminobenzoic acid ethyl ester or pentyl-4-dimethylaminobenzoate may be used in combination with the photopolymerization initiator.

  As auxiliary agents, anti-friction agents, anti-blocking agents, slip agents, pigment dispersants, carnauba wax, wax wax, lanolin wax, montan wax, paraffin wax, microcrystalline wax, natural wax, Fischer-Tropsch synthetic wax, Synthetic waxes such as polyethylene wax, polypropylene wax, polytetrafluoroethylene wax and polyamide wax, silicone additives, leveling agents and the like can be used as appropriate.

  Furthermore, extender pigments such as calcium carbonate, barium sulfate, alumina white, and silica may be added to the lithographic ink. For example, the average particle diameter of the extender pigment is often about 0.01 to 1 μm (preferably 0.01 to 0.1 μm), and calcium carbonate is often used. If necessary, the lithographic ink for forming the information pattern may be an infrared transmitting or absorbing pigment (for example, a white pigment such as titanium oxide, disazo yellow, etc.) unless the base material and the information pattern can be visually identified. A yellow pigment such as brilliant carmine 6B, a blue pigment such as phthalocyanine blue, a black pigment, particularly a black colorant prepared with a plurality of colorant components using subtractive color mixing). .

  In the lithographic ink of the present invention, the content of the near-infrared absorbing material may be such that the information pattern and the substrate can be optically discriminated or identified by the near-infrared reflectance (or absorption rate) even if the information pattern is thin. For example, it is about 1 to 20% by weight, preferably 1 to 15% by weight, and more preferably about 1 to 10% by weight with respect to the whole lithographic ink.

  If the content of the near-infrared absorbing material is small, the consistency and viscosity characteristics of the lithographic ink may change and the accuracy of the information pattern may decrease. Therefore, the lithographic ink containing the near infrared absorbing material may not contain the extender pigment depending on the kind of the near infrared absorbing material, but it is preferable to combine the near infrared absorbing material and the extender pigment. The extender pigment may have near infrared absorptivity or may not have near infrared absorptivity. The content of extender is 1 to 30% by weight, preferably 5 to 25% by weight, based on the whole lithographic ink. The weight ratio of the near-infrared absorbing material to the extender is 5/95 to 50/50, preferably 10/90 to 45/55, more preferably 15/85 to 40/60, and 20/80 to 30/70 is particularly preferred.

  In the lithographic ink, the ratio of each component is as follows: 1 to 10 parts by weight of near-infrared absorbing material, 5 to 25 parts by weight of extender pigment, 10 to 40 parts by weight of binder resin, 20 to 30 parts by weight of fats and oils, and 20 to 30 parts by weight of mineral oil. The ratio is preferably about 100 parts by weight, including additives such as auxiliaries.

  The lithographic ink has a viscosity of 100.0 Pa · s or less, preferably 40.0 Pa · s to 80.0 Pa · s, at 25 ° C. and a shear rate of 100 / s with a cone plate viscometer. When the viscosity is larger than the above numerical value, the fluidity and transferability are lowered, and the whole printed matter tends to be rough. Further, since the tack value of the ink increases with the viscosity, paper peeling and paper separation failure are likely to occur. The waterless lithographic ink preferably has a viscosity of 150 Pa · s or less at 25 ° C. and a shear rate of 100 / s with a cone plate viscometer, more preferably 60.0 Pa · s to 120 Pa · s. When the viscosity is larger than the above value, a tendency similar to that of the lithographic ink appears, and poor walling is likely to occur, leading to a decrease in printing quality such as missing dots, and a problem occurs in reading accuracy with respect to the infrared sensor. On the other hand, if the value is smaller than the above value, background stains are likely to occur, thereby obscure the information pattern formed on the printing paper surface, not only reducing the reading accuracy by the infrared sensor, but also hindering the printing itself. Become.

  The reflectance of the infrared rays by the information pattern is, for example, 0 to 60%, preferably 0 to 50%, more preferably about 0 to 40% with respect to the irradiated infrared rays (for example, infrared rays having a wavelength of 850 to 950 nm). .

  The information pattern can be composed of various forms of fine patterns that are difficult to recognize or identify visually. The shape may be a dot shape or a fine line shape.

  Since such an information pattern is difficult to identify visually, the portion applied to the substrate is not restricted and can be applied to any portion of the substrate, and process color ink (having no infrared absorption or Even when an information pattern is formed on an image portion formed by a low ink), the quality of the image is not impaired. In particular, the use of an ink whose information pattern and base material are difficult to distinguish in terms of color can further improve the image quality.

  An image by process ink is not necessarily required, but a predetermined image capable of transmitting infrared rays by using at least one chromatic or achromatic color ink, particularly at least three color process inks, on the substrate surface on which the information pattern is formed. Is often formed. The ink for forming this image is not particularly limited, and may be printing ink such as lithographic ink, letterpress ink, gravure ink, flexo ink, screen ink, ink jet ink, thermal transfer ink and the like. The same applies to the electrostatic image developing toner.

  Further, chromatic or three-color process inks are colorants that can transmit infrared rays, such as yellow pigments such as disazo yellow and condensed azo, lake red C, brilliant carmine 6B, rhodamine 6G, rhodamine B, and watching red. A red pigment, a blue pigment such as phthalocyanine blue, and a green pigment such as phthalocyanine green may be included. The achromatic or black ink colorant uses a subtractive color mixture, and a plurality of colorants that can transmit infrared rays, for example, a combination of yellow, red, and blue pigments, a combination of an orange pigment and a blue pigment, A black colorant prepared by a combination of a green pigment and a red pigment, a combination of a yellow pigment and a purple pigment, or the like is preferable.

  The substrate is not particularly limited as long as it has an infrared reflective surface, and is a paper substrate such as printing paper, gravure paper, fine paper, coated paper, baryta paper, art paper, cast coated paper, synthetic paper, polyolefin resin, etc. It may be a plastic substrate (or plastic sheet) composed of styrene resin, polyester resin, polyamide resin, etc., and a laminate in which a plurality of layers are laminated (for example, paper is laminated on a plastic sheet) A laminated body, a vapor deposition film, etc.). Moreover, the base material may be colored as long as it has infrared reflectivity. As the substrate, a paper substrate such as white coated paper, particularly a white paper substrate is often used. The infrared reflectance of the substrate is, for example, 50 to 100%, preferably 60 to 100%, more preferably 70 to 100% with respect to the infrared rays to be irradiated (for example, infrared rays having a wavelength of 850 to 950 nm).

  Inkjet ink can easily and accurately draw a fine dot pattern and a uniform thickness in pattern formation.

  In addition, since the near-infrared absorbing material of the present invention has high solubility in a solvent and compatibility with an ink vehicle, the near-infrared absorbing material in the ink composition is unlikely to aggregate with time, and even when used in an ink-jet ink. Stable ejection is possible without clogging the printer head.

  Ink-jet ink using the near-infrared absorbing material of the present invention is a solvent that is soluble in solvent, mixed with an additive, etc. Is obtained by adding a dispersant and dispersing, diluting if necessary, and mixing with other additives. For stirring dissolution or dispersion, a high-speed disperser, emulsifier, or the like can be used in addition to a stirrer using a normal stirring blade. The solution or dispersion thus obtained is sufficiently filtered with a filter having a pore size of 3 μm or less, preferably 1 μm or less, before or after dilution to give an inkjet ink. Prior to filtration of the filter, filtration by centrifugation can also be used, which can reduce production clogging and reduce the number of filter replacements, resulting in production efficiency.

  The ink-jet ink using the near-infrared absorbing material of the present invention can be detected as a printed matter by using 0.5 to 10% by weight, more preferably 1 to 8% by weight in the ink. If it is less than this, the pattern reading is not sufficient, and if it is more than this, the trace of recording becomes easy to distinguish. Ink-jet ink can be adjusted to an ink-jet ink suitable for a printer by using a near-infrared absorbing material and a solvent, but it is possible to adjust the type of solvent, whether or not a binder resin is used, the type, the amount, etc. according to the recording medium. .

  The solvent used in the inkjet ink using the near-infrared absorption line absorbing material of the present invention is excellent in solubility of the near-infrared absorbing material, and in view of drying on the recording medium, acetone, methyl ethyl ketone, methyl Examples thereof include ketone solvents such as isobutyl ketone and ester solvents such as ethyl acetate.

  In these solvents, a solvent such as N-methyl-2-pyrrolidone, γ-butyllactone, dimethyl sulfoxide or the like is added in the range of 0 to 5% by weight in order to increase the dissolution stability of the resin and the near-infrared absorber. Can be used together. However, these combined use lowers the drying property. Therefore, when the high-speed drying property is regarded as important, it is preferable to keep the use amount to a minimum.

    The resin used in the inkjet ink using the near-infrared absorption line absorbing material of the present invention is not only fixed on paper, but also on a recording medium such as a non-porous film to obtain good fixability. Used for. As such a resin, it is essential that the resin is not colored, and a resin excellent in solvent detachability is preferable. As such a resin, you may use 1 type of a polyketone resin, a polyacryl resin, and polyvinylpyrrolidone resin, and / or 2 or more types in mixture. These resins have good characteristics that the phenomenon of whitening during drying hardly occurs during drying of the ink. This is an extremely important characteristic particularly in applications that require stealth (invisibility) on the surface of the recording medium, and the above-described resins exhibit this characteristic. In addition, these resins are characterized in that even on a non-porous recording medium, the internal stress due to volume shrinkage is small and the fixing property is excellent.

  Furthermore, these resins used in inkjet inks using the near-infrared absorbing material of the present invention have a relatively low resin solution viscosity because of their excellent solubility, making it possible to adjust low-viscosity inkjet inks required for inkjet inks. Ink without coloring can be produced. Moreover, since it is excellent in re-dissolvability with a solvent, high reliability is ensured in continuous discharge performance with a printer.

  As described above, the inkjet ink using the near-infrared absorbing material of the present invention uses the above-described resin, so that ejection stability in a printer, fixability on a recording medium, transparency, and water resistance are improved. An ink jet ink excellent in balance can be formed.

  In addition, when a polyvinyl pyrrolidone resin is used in the inkjet ink using the near infrared ray absorbing material of the present invention, the fixing property to a recording medium such as a non-porous film is weak, stickiness occurs, and the ejection property is adversely affected. It is desirable to use 0.5 to 3% in the ink.

  Further, as a resin used in the ink-jet ink using the near-infrared absorbing material of the present invention, in addition to the above-mentioned resins, other resins may be mixed and used for adjusting the fixing property, the viscosity of the ink-jet ink, the solubility, etc. Good. Examples of these resins include cellulose-based, phenol-based, epoxy-based, epoxyphenol-based, polyester-based, polyamide-based, polyurethane-based, butyral-based, silicon-based, rosin, and rosin-modified resins (phenol-modified, maleic acid-modified, fumarate). Acid modification etc.), acrylamide, alkyd, shellac, acrylic, styrene-acrylic resins, etc., can be exemplified, the solubility in a solvent substantially free of water is good, and the viscosity of inkjet ink can be adjusted moderately. Choose one. These resins are used in an ink-jet ink in an amount of 0 to 3% by weight as required.

  The resin used for the inkjet ink using the near infrared ray absorbing material of the present invention is used in a total of 3 to 35% by weight, preferably 5 to 30% by weight, in the inkjet ink. If the amount is less than this amount, sufficient near-infrared absorbing material cannot be fixed to a non-permeable recording medium. On the other hand, when the amount is larger than this amount, the viscosity of the ink-jet ink is increased, and the ejection stability may be lowered. In addition, the resin layer is thickly covered around the near-infrared-absorbing recording material, and the near-infrared absorption ability of the compound may be reduced.

  The ink-jet ink using the near-infrared absorbing material of the present invention is adjusted as a liquid having a viscosity of 0.8 to 15 mPas (25 ° C.), although it depends on the recording apparatus. The surface tension is preferably 20 to 45 mN / m.

  When the inkjet ink using the near-infrared absorbing material of the present invention is used in a continuous type printer, the electrical conductivity is 0.1 to 20 millisiemens (mS / cm), and further 0.5 to 10 millisiemens. It is preferable to adjust to (mS / cm). As the conductivity adjusting agent, sodium thiocyanate, potassium thiocyanate, ammonium thiocyanate, lithium nitrate, tetrabutylammonium bromide and the like can be used, and tetrabutylammonium bromide is particularly preferable from the viewpoint of stability over time. Such a conductivity adjusting agent is preferably used at 5 wt% or less in the ink.

  When used in a continuous printer, the solvent in the ink jet ink is volatilized by continuous use of ink jet ink ejection and recovery using the near-infrared absorbing material of the present invention, and the solid content of the ink jet ink is concentrated over time. And the viscosity increases. For this reason, in an inkjet ink, the diluent for replenishing the volatile component in an inkjet ink and adjusting the solubility and viscosity of resin and a near-infrared absorption material is required. The diluent is preferably the same as the solvent component in the ink-jet ink and has a higher volatile solvent component than the ink-jet ink.

  Moreover, the inkjet ink using the near-infrared absorbing material of the present invention can use a surface conditioner for the purpose of preventing the ink from spreading and repelling when printing on a non-permeable film or the like. Examples of such a surface conditioner include a silicon-modified system, an acrylic copolymer meter, and a mixture thereof. Among these, it is particularly preferable to use a polyether-modified silicon compound. Specific examples include BYK-331, BYK-333, BYK-341 manufactured by Big Chemie, FZ2123 manufactured by Nippon Unicar Co., Ltd., and the like.

  These silicon compounds are suitable for adjusting the appropriate spread of the ink on the film, and can form ink-jet clean dots, and are advantageous because an image can be formed that allows optical reading.

  Further, an antifoaming agent can be added to prevent the circulation or movement of the ink-jet ink using the near-infrared absorbing material of the present invention and the generation of bubbles during production. As such an antifoaming agent, a silicon modified system, an acetylenic diol system, an organic substance system, and a mixed system thereof can be used. Examples of the silicone-modified antifoaming agent include BYK-065 and BYK-088 manufactured by BYK Chemie. Examples of the acetylene-based antifoaming agent include Surfinol DF-110D and Surfinol DF-37 manufactured by Nissin Chemical Industry Co., Ltd. Examples of organic substances include Surfinol DF-75 and DF-210 manufactured by Nissin Chemical Industry Co., Ltd.

  Further, an antifoaming agent can be added to the ink jet ink using the near infrared ray absorbing material of the present invention in order to prevent the circulation or movement of the ink and the generation of bubbles during the production of the ink jet ink.

  The toner for developing an electrostatic charge image of the present invention is composed of a binder resin (resin constituting a vehicle), a near-infrared absorbing material of the present invention, a release agent, a charge control agent, an external additive, a lubricant and the like as necessary. ing.

  In the present invention, the near-infrared absorbing material represented by the general formula (1) is preferably added in an amount of 1 to 10% by weight, more preferably 2 to 8% by weight, in the electrostatic image developing toner. When the addition amount exceeds 10% by weight, the content of the binder resin is relatively reduced, and the toner fixing performance is deteriorated. Further, it becomes impossible to obtain a desired charge amount as the toner. On the other hand, if it is less than 1% by weight, there is a possibility that sufficient absorption for detection by an infrared sensor cannot be obtained. In particular, when 2 to 6% by weight is added, no toner scattering is observed in the non-image area, and good image characteristics can be obtained.

  The infrared reflectance of the printed matter (information pattern) obtained from the toner of the present invention is in the range of 0 to 60% in terms of reflectance measured by reflection spectrum measurement with respect to the irradiated infrared rays (infrared rays having a wavelength of 850 to 950 nm). . More preferably, it is 0 to 50%, and more preferably about 0 to 40%.

  The toner of the present invention preferably has a reflectance of 75 to 100% in the visible light region (here, 450 to 700 nm). If the reflectance is lower than 75% in the visible light region, the print information can be seen with the naked eye and cannot be used.

  The binder resin used in the toner of the present invention is preferably a colorless, white, or light color.

  Examples of binder resins that can be used include homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene, and substituted products thereof; styrene-p-chlorostyrene copolymer, styrene-vinyltoluene copolymer Polymer, styrene-vinyl naphthalene copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl Styrenes such as methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer Copolymer or cross-linked Tylene copolymer; polyvinyl chloride, phenol resin, natural modified phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy Examples thereof include resins, xylene resins, polyvinyl butyral, terpene resins, coumarone indene resins, and petroleum resins. Of these, polyester resins and styrene copolymers are preferably used.

  In the styrene copolymer, examples of the comonomer for the styrene monomer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, A monocarboxylic acid having a double bond such as methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, or a substituted product thereof; for example, maleic acid, methyl maleate, Dicarboxylic acids having a double bond such as butyl maleate and dimethyl maleate and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; Ethylenic olefins such as alkylene; such as vinyl methyl ketone, vinyl ketones such as vinyl hexyl ketone; ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl ethers such as vinyl isobutyl ether; vinyl monomers can be mentioned. These may be used alone or in combination of two or more.

As a crosslinking agent used when producing a crosslinked styrene-based copolymer, a compound having two or more polymerizable double bonds is mainly used. For example, aromatic divinyl such as divinylbenzene and divinylnaphthalene. Compound; for example, carboxylic acid ester having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate; divinyl compound such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; And compounds having three or more vinyl groups are used alone or as a mixture. The styrenic polymer has at least one peak in the region of 3 × 10 ^{3 to} 5 × 10 ⁴ in the molecular weight distribution measured by GPC, and at least one other peak or shoulder in the region of 10 ⁵ or more. The styrenic copolymer is preferred from the standpoint of fixability.

  In producing the vinyl polymer, a polymerization initiator is used. Any conventionally known polymerization initiator can be used. Examples of the polymerization initiator include benzoyl peroxide, lauroyl peroxide, tertiary butyl hydroperoxide, tertiary butyl peroxybenzoate, ditertiary butyl peroxide, cumene hydroperoxide, dicumyl peroxide, azo Isobutyronitrile, azobisvaleronitrile, and the like are preferably used conventionally. The use ratio of the polymerization initiator to the vinyl monomer is generally 0.2 to 5% by mass. The polymerization temperature is appropriately selected according to the type of monomer and initiator used.

  Examples of the release agent include aliphatic hydrocarbons, fatty acid metal salts, higher fatty acids, fatty acid esters or partially saponified products thereof, silicone oil, and various waxes. Among these, waxes such as low molecular weight polyethylene having a weight average molecular weight of about 1000 to 10,000, low molecular weight polypropylene, microcrystalline wax, carnauba wax, sazol wax, and paraffin wax are preferable. These are usually added to the toner in an amount of about 0.5 to 5% by weight based on 100 parts by weight of the toner.

  The toner of the present invention may contain a colorless or light-colored charge control agent as long as it does not interfere with the hue as necessary. As the charge control agent, a positive charge control agent or a negative charge control agent is used according to the polarity of the electrostatic image on the electrostatic latent image carrier to be developed.

  As the positive charge control agent, quaternary ammonium salt compounds (for example, tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylbenzylammonium tetrafluoroborate), quaternary ammonium salt organic tin oxide (for example, dibutyltin) Oxide, dioctyltin oxide, dicyclohexyltin oxide), diorganotin borate (dibutyltin borate, dioctyltin borate, dicyclohexyltin borate), electron donating substances such as polymers having amino groups, etc. are used alone or in combination of two or more. be able to.

On the other hand, as negative charge control agents, aromatic hydroxycarboxylic acid zinc salt, calcium salt, chromium salt, aryloxycarboxylic acid divalent or trivalent metal salt or metal chelate (complex) such as salicylic acid or salicylic acid derivative, etc. , Fatty acid soaps, naphthenic acid metal salts and the like. These charge control agents are usually used in a proportion of 0.3 to 6 parts by weight, preferably 0.5 to 5 parts by weight, based on 100 parts by weight of the toner.
The black toner and color toner used together with the toner of the present invention are colorants that can transmit infrared rays, such as yellow pigments such as disazo yellow and condensed azo, lake red C, brilliant carmine 6B, rhodamine 6G, rhodamine B, and watching. A red pigment such as red, a blue pigment such as phthalocyanine blue, and a green pigment such as phthalocyanine green may be included. In addition, the colorant for black toner is a plurality of colorants that can transmit infrared rays using subtractive color mixing, such as a combination of yellow, red, and blue pigments, a combination of orange and blue pigments, and a green pigment. A black colorant prepared by a combination of a red pigment and a yellow pigment and a purple pigment is preferred.

  As the external additive used in the toner of the present invention, a fluidizing agent, an abrasive, a conductivity imparting agent, a lubricant and the like can be used. As the base material of the fluidizing agent used in the present invention, it is possible to use fine powders such as silica, alumina, titania, magnesia, amorphous silicon-aluminum co-oxide, amorphous silicon-titanium co-oxide. it can. The fluidizing agent as an external additive has not only the purpose of imparting fluidity to the toner but also the role of imparting and controlling toner chargeability. That is, the external additive adheres to the outermost part of the toner, thereby greatly affecting the chargeability of the toner.

The particles used for the fluidizing agent can be used as they are without surface treatment, but the environmental stability is impaired by the hygroscopicity, and the fluidizing agent adheres to the surface of the photosensitive drum. There may be a problem that filming occurs and an image defect is caused. Therefore, it is preferable to perform surface treatment of the particles used for the fluidizing agent to impart hydrophobicity. As the surface treating agent for the fluidizing agent used in the present invention, organoalkoxysilanes such as dimethyldimethoxysilane and dimethyldiethoxysilane, Organochlorosilanes such as dimethyldichlorosilane, trimethylchlorosilane, octadecyltrichlorosilane, t-butyldimethylchlorosilane, silazanes such as hexamethyldisilazane, organoaminosilanes such as bis (dimethylamino) dimethylsilane, and silicone oil compounds Can be used.

  As the external additive other than the fluidizing agent used in the present invention, the following known additives can be used for lubricants, abrasives, conductivity imparting agents and the like. Examples of the lubricant include polytetrafluoroethylene and zinc stearate, and examples of the abrasive include strontium titanate, calcium titanate, barium titanate, calcium carbonate, chromium oxide, silicon carbide, tungsten carbide, and silicon nitride. The body is mentioned. These abrasives have an effect of removing adhering toner components and filming substances on the surface of the photosensitive drum by polishing and scraping, and are used in combination with the above-mentioned fluidizing agent that has been surface-treated with silicone oil. A great effect can be obtained. As the conductivity imparting agent, a metal oxide such as tin oxide can be added.

  The toner according to the present invention can be manufactured using a conventionally known toner manufacturing method as long as toner particles can be obtained in a state where the infrared absorbing material is uniformly mixed in the binder resin. The toner production methods are roughly classified into two types: a pulverization method obtained through kneading and pulverization steps, and a polymerization method obtained by chemical polymerization. In the case of the pulverization method, for example, the toner constituent materials as described above are sufficiently mixed by a mixer such as a ball mill or a Henschel mixer, and then kneaded well using a thermal kneader such as a hot roll kneader, a uniaxial or biaxial extruder. Then, after cooling and solidification, a method of manufacturing by a method of coarsely pulverizing mechanically using a pulverizer such as a hammer mill, then finely pulverizing with a jet mill, a mechanical pulverizer, etc., and then classifying. The toner base particles (classified toner) obtained in this manner are mixed thoroughly with an external additive using a mixer such as a Henschel mixer to be finally used as a toner. The toner used in the present invention preferably has a volume average particle size of 3 to 15 μm, more preferably 5 to 12 μm.

  On the other hand, in the case of the polymerization method, a method for producing toner by the so-called microcapsule method in which other toner constituent materials are dispersed in a binder resin solution and then spray-dried, and a predetermined material as a monomer for forming the binder resin And a method of obtaining a toner by emulsion or suspension polymerization. In the emulsion polymerization method, resin particles having a particle size of submicron are associated with an internal additive such as a colorant or wax that has been pre-emulsified in water in the aggregation step to obtain a particle size of a desired toner size. In the suspension polymerization method, polymerization is performed by dispersing and heating necessary materials such as a polymerization initiator, a colorant, a wax, and a charge control agent in a monomer.

  The toner of the present invention can also be used with a carrier as a two-component developer. As the carrier, any carrier conventionally used in a two-component dry developer can be used. Examples of such carriers include ferromagnetic powder such as iron powder or alloy powder of ferromagnetic metal, metal oxide such as iron oxide, ferrite powder composed of elements such as nickel, copper, zinc, magnesium, barium, Magnetic powder carrier made of magnetic powder such as magnetite powder, magnetic powder resin coated carrier coated with these magnetic powder with resin, binder carrier made of magnetic powder and binder resin, glass beads with or without resin coating, etc. Can be mentioned. These carriers usually have a particle size of about 15 to 100 μm, preferably about 20 to 80 μm. As the coating resin for the coat carrier, olefin resin, styrene resin, styrene / acrylic resin, silicone resin, ester resin, fluorine-containing polymer resin silicone resin, and styrene resin are used.

  In the electrophotographic system, it is necessary to fix the formed toner image on the surface of a recording material (image support) such as paper. As this method, fixing by pressure or fixing by heat is known. The fixing method using pressure is difficult to improve the adhesiveness to paper or the like, so that it is practically scarce. At present, a so-called hot-melt fixing method in which toner is fixed by melting with heat is often used. The hot melt fixing method is roughly classified into a heat roll and heat belt fixing method which is contact fixing, and a flash fixing method which is non-contact fixing. The heat roll and heat belt fixing method is mainly used in the current electrophotographic method because the toner is melted by bringing a heat transfer member into contact with the toner image, and high efficiency can be expected.

  The gravure ink of the present invention is preferably added with 1 to 20 parts by weight of the near-infrared absorbing material of the present invention.

  In the gravure ink of the present invention, as a binder resin for gravure printing ink containing a near infrared absorbing material, for example, styrene / maleic acid, acrylic / styrene resin, polystyrene, polyester, polycarbonate, epoxy resin, polyurethane resin, polybutyral resin , Polyacrylic acid ester, styrene / butadiene copolymer, styrene / butadiene / acrylic acid copolymer, polyvinyl acetate and the like. These resins can be used alone or in admixture of two or more. Among these resins, urethane resins are preferably used because of their good adhesion to the substrate.

  A curing agent can be used in combination for the purpose of improving the film strength, heat resistance, water resistance, solvent resistance, etc. of the gravure printing ink. As the curing agent, isocyanate, oxazoline, carbodiimide, ethyleneimine, and the like can be used. From the viewpoint of film strength and film physical properties, isocyanate-based curing agents are preferred.

  As the organic solvent, known organic solvents used for gravure printing such as ethanol, isopropyl alcohol, methyl acetate, methyl isobutyl ketone, 1-methoxy-2-propanol, toluene, xylene, etc. can be used, but preferably toluene, xylene It is a solvent having good solubility in the near-infrared absorbing material.

  An antifoaming agent, a leveling agent, a wax, a lubricant, a plasticizer, an ultraviolet absorber and the like can be used in the gravure printing ink containing the near-infrared absorbing material as necessary for improving printability and film properties.

  In the adjustment of gravure printing ink containing near-infrared absorbing material, if the near-infrared absorbing material dissolves in the organic solvent used in the ink, the ink can be adjusted by mixing and dissolving, but if not dissolved or dissolved If this is difficult, it is necessary to disperse using a disperser. Dispersers include paint conditioners (manufactured by Red Devil), ball mills, sand mills (such as “Dyno mill” manufactured by Shinmaru Enterprises), attritors, pearl mills (such as “DCP mill” manufactured by Eirich), coball mills, homomixers, Examples thereof include a homogenizer (such as “CLEARMIX” manufactured by M Technique Co., Ltd.), a wet jet mill (“GENUS PY” manufactured by Genus, “Nanomizer” manufactured by Nanomizer), and the like. When media are used in the disperser, glass beads, zirconia beads, alumina beads, magnetic beads, styrene beads, or the like can be used.

  The ink composition of the present invention includes identification documents such as passports, driver's licenses, employee ID cards, stock certificates, bonds, checks, passbooks, lottery tickets, coupon tickets, commuter passes, tickets and other securities, ID cards, credit cards, This is effective in preventing unauthorized use of counterfeit cards such as cash cards, gift cards, and prepaid cards. Furthermore, by applying the information pattern to various printed materials, it is useful to reproduce information corresponding to the information pattern as visible, audible, and readable information such as voice, image, character, and symbol.

EXAMPLES The present invention will be described in more detail with reference to the following examples. However, the following examples do not limit the scope of rights of the present invention. In the examples, “part” represents “part by weight”.
[Production Example 1] Production of near-infrared absorbing material P-1 [Synthesis of Compound 1]

Under a nitrogen stream, dimethylphenylglyoxal (70 g, 388 mmol), bromoethylbenzene (72 g, 388 mmol), and 500 ml of dichloroethane were charged into a four-necked flask, and titanium tetrachloride (110 g, 583 mmol) was slowly added dropwise thereto at room temperature for 3 hours. Stirring was performed. After completion of the reaction, water was added for extraction, followed by evaporation and recrystallization with hexane. Yield 60%.
[Synthesis of Compound 2]

Benzoin derivative compound 1 (50 g, 94 mmol) and diphosphorus pentasulfide (12.5 g, 56 mmol) in 200 ml of dioxane were added to a four-necked flask and refluxed for 2 hours in a nitrogen atmosphere. After the reaction, filtration was performed, and an aqueous solution of NiCl 2 · 6H 2 O (11.2 g, 47 mmol) was added to the filtrate, followed by refluxing again for 2 hours. After completion of the reaction, water and methanol were added and stirred for a while, followed by filtration and collection. Yield 45%.
[Synthesis of P-1]

Compound 2 (0.9 g, 1.06 mmol) synthesized above, 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane (0.388 g, 1.06 mmol) and K2CO3 (1.16 g, 8 .44 mmol) and 40 ml of DMF were added to a four-necked flask and stirred at 80 ° C. for 8 hours under a nitrogen atmosphere. After completion of the reaction, filtration and evaporation were performed, and the resulting solution was added dropwise to a water / methanol = 1/2 solution and washed. The target product was recovered by filtration. Yield 68%.

[Production Example 2] Synthesis of near-infrared absorbing material P-2 1,3-bis [2 (4-hydroxyphenyl) -2-instead of 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane The compound was synthesized according to the synthesis method of P-1, except that propyl] benzene was used. Yield 70%.
[Production Example 3] Synthesis of P-3 Except for using 4-4 ′-(1,3-dimethylbutylidene) diphenol in place of 2,2-bis (4-hydroxy-3,5-dichlorophenyl) propane Synthesized according to the synthesis method of P-1. Yield 75%.
[Production Example 4] Production example of rosin-modified phenolic resin
(Rosin-modified phenolic resin A, for lithographic ink)
To a four-necked flask equipped with a stirrer, a cooler, and a thermometer, 1000 parts of P-octylphenol, 850 parts of 35% formalin, 60 parts of 93% sodium hydroxide and 1000 parts of toluene were added, and the mixture was heated at 80-90 ° C. for 6 hours. Reacted. Thereafter, 125 parts of 6N hydrochloric acid and 1000 parts of tap water were added, and the mixture was stirred and allowed to stand. The upper layer was taken out to obtain 2000 parts of a toluene solution of a resole-type phenol resin having a nonvolatile content of 49%. A.

       A four-necked flask equipped with a stirrer, a condenser with a water separator, and a thermometer was charged with 1000 parts of gum rosin, dissolved at 200 ° C. while blowing nitrogen gas, and 1800 parts of the resole liquid A produced above was added. After reacting at 230 ° C. for 4 hours while removing toluene, 110 parts of glycerin was added and reacted at 250 ° C. for 10 hours to obtain an oxidation of 20 or less, a weight average molecular weight of 40000, Shin Nippon Petrochemical Co., Ltd. AF Solvent No. 6 The rosin-modified phenol resin A for lithographic ink having a white turbidity temperature of 80 ° C. and a resin viscosity of 10.0 Pa · s was obtained.

[Production Example 5] (Rosin-modified phenolic resin B, for waterless lithographic ink)
To a four-necked flask equipped with a stirrer, a cooler, and a thermometer, 720 parts of P-octylphenol, 375 parts of P-dodecylphenol, 290 parts of paraformaldehyde, 60 parts of 93% sodium hydroxide, and 800 parts of xylene were added. The reaction was carried out at -90 ° C for 5 hours. Thereafter, 125 parts of 6N hydrochloric acid and 200 parts of tap water were added, stirred and allowed to stand, and the upper layer part was taken out to obtain 2000 parts of a xylene solution of a resole-type phenol resin having a nonvolatile content of 63%. B.

       A four-necked flask equipped with a stirrer, a condenser with a water separator and a thermometer was charged with 600 parts of gum rosin, dissolved at 200 ° C. while blowing nitrogen gas, and 770 parts of the resole solution B produced above was added. After reacting at 220 ° C. for 4 hours while removing toluene, charge 67 parts of glycerin and react at 250 ° C. for 12 hours to obtain an oxidation of 18 or less, a weight average molecular weight of 200,000, Shin Nippon Petrochemical Co., Ltd. AF Solvent No. 6 The rosin-modified phenol resin B for waterless lithographic ink having a cloudiness temperature of 100 ° C. and a resin viscosity of 23.0 Pa · s was obtained.

Varnish Production Example [Production Example 6] (Varnish Production Example 1, for lithographic ink)
42 parts of rosin-modified phenolic resin A, 33 parts of soybean oil, 24 parts of AF solvent 6 (solvent manufactured by Shin Nippon Petrochemical Co., Ltd.), 1.0 part of ALCH (gelator manufactured by Kawaken Fine Chemicals Co., Ltd.) The mixture was heated and stirred at 190 ° C. for 1 hour to obtain a lithographic ink varnish A.

[Production Example 7] (Varnish Production Example 2 for waterless lithographic ink)
42 parts of rosin-modified phenolic resin A, 28 parts of soybean oil, 5 parts of soybean fatty acid isobutyl ester (manufactured by Toei Chemical Co., Ltd.), 10 parts of dialen 168 (Mitsubishi Chemical Corporation, 1-hexadecene, 1-octadecene mixture) , AF Solvent No. 6 (Shin Nippon Petrochemical Co., Ltd. solvent) 14 parts, ALCH (Kawaken Fine Chemical Co., Ltd. gelling agent), 1.0 part heated and stirred at 190 ° C for 1 hour, no water Varnish B for lithographic ink was obtained.

[Production Example 8] (Varnish Production Example 3, UV curable lithographic ink)
25 parts of Dap Tote DT170 (manufactured by Toto Kasei Co., Ltd.) is added to 75 parts of DPHA (manufactured by Nippon Kayaku Co., Ltd.) heated to 90 ° C.-100 ° C., and heated and stirred at 90 ° C.-100 ° C. for 1 hour. A varnish C for curable lithographic ink was obtained.

[Production Example 9] (Varnish Production Example 4, UV-curable waterless lithographic ink)
32 parts of Dap Tote DT170 (manufactured by Tohto Kasei Co., Ltd.) is added to 68 parts of DPHA (manufactured by Nippon Kayaku Co., Ltd.) heated to 90 ° C-100 ° C, and heated and stirred at 90 ° C-100 ° C for 1 hour, ultraviolet rays A curable varnish D for waterless lithographic ink was obtained.

       The cloudiness temperature was measured with a 10% diluted state of AF Solvent 6 manufactured by Nippon Petrochemical Co., Ltd., using NOVOCONTROL manufactured by CHEMOTRONIC. The resin viscosity is a viscosity value at 25 ° C. measured by a varnish cone plate viscometer obtained by heating and stirring a mixture having a weight ratio of resin / linseed oil = 1/2 at 180-200 ° C.

[Production Example 10] Example of production of medium-based ink
(Medium base ink production example 1, for lithographic ink)
Varnish A 33.5 parts, calcium carbonate 22 parts, AF solvent No. 6 8.2 parts in a 3 roll mill, temperature condition 60 ° C., particle size is 7.5 microns or less with a dispersion particle size measuring instrument (grind meter) The mixture was kneaded until it was obtained to obtain a medium base ink A for lithographic ink.

[Production Example 11] (Medium-based ink production example 2, for waterless lithographic ink)
Varnish B 33.5 parts, calcium carbonate 22 parts, AF solvent 6 No. 8.2 part with 3 roll mill, temperature condition 60 ° C., particle size is 7.5 microns or less with dispersion particle size measuring instrument (grind meter) The mixture was kneaded until it was obtained to obtain a medium base ink B for waterless lithographic ink.

[Production Example 12] (Medium-based ink production example 3, for ultraviolet curable lithographic ink)
Varnish C 35.5 parts, calcium carbonate 22 parts, Aronix M-408 6.2 parts in a 3 roll mill, temperature condition 60 ° C., particle size is 7.5 microns or less with a dispersion particle size measuring instrument (grind meter) The mixture was kneaded until it was obtained to obtain a medium base ink C for ultraviolet curable lithographic ink.

[Production Example 13] (Medium-based ink production example 4, UV-curable waterless lithographic ink)
Varnish D 32.5 parts, calcium carbonate 22 parts, Aronix M-408 9.2 parts at 3 roll mill, temperature condition 60 ° C, particle size is 7.5 microns or less with dispersion particle size measuring instrument (grind meter) The mixture was kneaded until it was obtained to obtain a medium base ink D for UV-curable waterless lithographic ink.

Production Example of Near Infrared Absorption Base Ink [Production Example 14] (Near Infrared Absorption Base Ink Production Example 1, for lithographic ink)
According to the composition shown in Table 1, the mixture was kneaded with a three-roll, temperature condition of 30 ° C. with a dispersed particle size meter (grind meter) until the particle size became 7.5 microns or less, and a near infrared absorption base for lithographic ink Ink A was obtained. From the particle size measurement with a grindometer, coarse particles of 7.5 microns or more were not confirmed, and the dispersibility with respect to varnish A was very good.

[Production Example 15] (Near-infrared absorption base ink production example 2, for waterless ink)
In accordance with the composition shown in Table 1, the mixture was kneaded with a three-roll, temperature condition of 30 ° C. with a dispersed particle size measuring device (grind meter) until the particle size became 7.5 microns or less, and near infrared for waterless lithographic inks Absorption base ink B was obtained. From the particle size measurement with a grindometer, coarse particles of 7.5 microns or more were not confirmed, and the dispersibility with respect to varnish B was very good.

[Production Example 16] (Near-infrared absorption base ink production example 3, for ultraviolet curable lithographic ink)
According to the composition shown in Table 1, the mixture was kneaded with a three-roll, temperature condition of 30 ° C. with a dispersed particle size measuring device (grind meter) until the particle size became 7.5 microns or less, and near red for ultraviolet curable lithographic inks. An outer absorption base ink C was obtained. From the particle size measurement with a grindometer, coarse particles of 7.5 microns or more were not confirmed, and the dispersibility with respect to varnish C was very good.

[Production Example 17] (Near-infrared absorption base ink production example 4, UV-curable waterless lithographic ink)
According to the composition shown in Table 1, three rolls and temperature conditions of 30 ° C. are kneaded with a dispersed particle size meter (grind meter) until the particle size is 7.5 microns or less, and used for UV-curable waterless lithographic ink Near-infrared absorption base ink D was obtained. From the particle size measurement with a grindometer, coarse particles of 7.5 microns or more were not confirmed, and the dispersibility with respect to varnish D was very good.
[Example 1] Lithographic ink According to the composition shown in Table 2, medium base ink A and near-infrared absorbing base ink A, varnish A, metal dryer, AF Solvent No. 6, friction resistance, at 3 rolls and at a temperature of 30 ° C. Dilution adjustment was carried out with the compound and the drying inhibitor, and the near infrared absorption lithographic printing ink NIR-1 was obtained at a viscosity of 60.0 Pa · s.
[Example 2] Waterless lithographic ink In accordance with the formulation shown in Table 2, medium base ink B and near-infrared absorbing base ink B were mixed with varnish B, metal dryer, AF solvent No. 6, Dilution adjustment was performed using a friction-resistant compound and a drying inhibitor, and a near-infrared absorbing waterless lithographic printing ink NIR-2 was obtained at a viscosity of 90.0 Pa · s.
[Example 3] UV curable lithographic ink According to the composition shown in Table 2, medium base ink C and near infrared absorption base ink C were mixed with varnish C, Irgacure 907, and Aronix M-408 at a temperature of 30 ° C. Then, dilution adjustment was performed with a friction-resistant compound and a polymerization inhibitor, and a near infrared absorption ultraviolet curable lithographic printing ink NIR-3 was obtained at a viscosity of 60.0 Pa · s.
[Example 4] UV curable waterless lithographic ink In accordance with the formulation of Table 2, medium base ink D and near infrared absorption base ink D, varnish D, Irgacure 907, Aronix M at 3 rolls and temperature condition of 30 ° C. The dilution was adjusted with -408, a friction-resistant compound, and a polymerization inhibitor, and a near-infrared absorbing ultraviolet curable waterless lithographic printing ink NIR-4 was obtained with a viscosity of 90.0 Pa · s.
[Comparative Example 1] Lithographic ink In accordance with the composition shown in Table 2, medium base ink A was diluted and adjusted with varnish A, metal dryer, AF Solvent No. 6, compound, and drying inhibitor at a temperature of 30 ° C. A medium ink M-1 for lithographic printing was obtained at a viscosity of 60.0 Pa · s.
[Comparative Example 2] Waterless lithographic ink In accordance with the composition shown in Table 2, the medium base ink B was diluted with varnish B, metal dryer, AF Solvent No. 6, compound, and drying inhibitor at 3 rolls and a temperature condition of 30 ° C. After adjusting, a waterless lithographic printing medium ink M-2 was obtained at a viscosity of 90.0 Pa · s.
[Comparative Example 3] UV curable lithographic ink According to the composition shown in Table 2, the medium base ink C was prepared with varnish C, Irgacure 907, Aronix M-408, compound and polymerization inhibitor at 3 rolls and temperature condition of 30 ° C. Dilution adjustment was performed, and ultraviolet curable lithographic printing medium ink M-3 was obtained with a viscosity of 60.0 Pa · s.
[Comparative Example 4] UV-curable waterless lithographic ink In accordance with the formulation shown in Table 2, medium-based ink D was applied to varnish D, Irgacure 907, Aronix M-408, compound, and polymerization prohibited at 3 rolls and at a temperature of 30 ° C. Dilution adjustment was performed with an agent to obtain UV-curable waterless lithographic printing medium ink M-4 with a viscosity of 90.0 Pa · s.

  The inks obtained in Examples 1 to 4 and Comparative Examples 1 to 4 were printed using an offset sheet-fed printing press to obtain proof-print samples. The print sample creation conditions are described below.

[Lithographic ink printing conditions]
Printing machine: LITHRONE 426 (manufactured by Komori Corporation, sheet-fed chrysanthemum half-color 4-color machine)
Version: CTP version HP-F for flat plate (Fuji Film Graphic Systems Co., Ltd.)
Dampening solution: AQUAUNITY SNP 2.0% (manufactured by Toyo Ink Manufacturing Co., Ltd.)
Paper: Tokuhishi Art Double Side N 79.5kg Y Eye (Mitsubishi Paper Co., Ltd.)
Printing speed: 8000 sheets / hour
[Waterless planographic ink printing conditions]
Printing machine: LITHRONE 426 (manufactured by Komori Corporation, sheet-fed chrysanthemum half-color 4-color machine)
Version: CTP version VG5 for waterless flat plate (Toray Industries, Inc.)
Paper: Tokuhishi Art Double Side N 79.5kg Y Eye (Mitsubishi Paper Co., Ltd.)
Printing speed: 8000 sheets / hour
[Verification of visibility]
In order to evaluate the visibility of the near-infrared absorbing material used in the present invention, the printed sample was observed with the naked eye, and it was confirmed whether the hue difference between the blank paper portion and the printed portion could be identified. Evaluation was carried out according to the following criteria.

The hue difference cannot be confirmed visually. : ○
The hue difference can be clearly confirmed visually. : ×
[Spectral reflectance measurement]
In order to evaluate the sensitivity of the near-infrared absorbing material used in the present invention to the infrared sensor, the spectral reflectance curve (UV3600, manufactured by Shimadzu Corporation) of the printed sample was measured. The measurement conditions are described below.

Measuring device: UV3600 (Shimadzu Corporation ultraviolet visible near infrared spectrophotometer)
Wavelength range: 350.00-1000.00nm
Sampling pitch: 0.50 nm
Scanning speed: High speed Photometric value: Reflectance Slit width: 20nm
Detector: Integrating sphere Baseline: Tokuhishi art double-sided N 79.5kg Y eyes (Mitsubishi Paper Co., Ltd.)
Measurement location: 100% solid portion of print sample Further, regarding the evaluation of sensitivity to the infrared sensor, the following judgment is made using the reflectance at the absorption maximum wavelength of 870 nm of the ink of Example 1-4 including the near infrared absorber P-1. Judged by criteria.

40% to 100%: poor sensitivity 0% to 40%: good sensitivity [photographing with an infrared reader]
Using a microscope (MX-61IR manufactured by Olympus Co., Ltd.) equipped with a transmissive filter in the wavelength region of 850 nm to 950 nm, an image of the printed sample (halftone dot = 20%) was taken.

As shown in Table 3, the ink composition of Example 1-4 containing a near-infrared absorbing material having a repeating unit represented by the general formula (1) was not colored when printed and could not be visually confirmed. However, the spectral reflectance in the near-infrared region (absorption maximum wavelength; 870 nm) was as good as about 36%, and the halftone dot shape could be clearly confirmed by a microscope equipped with an infrared transmission filter. On the other hand, the ink composition of Comparative Example 1-4 was not colored when printed and could not be visually confirmed. However, the spectral reflectance in the near infrared region (absorption maximum wavelength 870 nm) was 96%, and the sensitivity was poor. Also, the Dot shape could not be confirmed by a microscope equipped with an infrared transmission filter.
(Near infrared absorption base ink composition ratio)

(Ink blend ratio)

[Example 5] Inkjet ink An inkjet ink was prepared by mixing the following raw materials.

Near infrared absorbing material (P-1) of Production Example 1 2.0 parts Polyketone resin (acid value 270, softening point 100 ° C.) 15.0 parts Polyvinylpyrrolidone resin (weight average molecular weight 6000 to 15000) 2.0 parts Methyl ethyl ketone 75. 0 parts N-methyl-2-pyrrolidone 5.0 parts tetrabutylammonium bromide 1.0 part silicon additive 0.02 part antifoaming agent 0.03 part

The raw material was sufficiently dissolved by a stirrer and then filtered through a glass fiber filter (Whatman GF / B) having a pore size of 1.0 μm to obtain a recording liquid having a viscosity of 4.2 mPas. This recording liquid was put in an “Excel printer 170i” manufactured by Videojet and recorded on a standard PET film “FT 50 μm” manufactured by Teijin Dupont Film Co. at a resolution of 60 dpi.

The recorded matter was hardly discernable under visible light, and good stealth was obtained. As a result of measuring the spectral reflectance, a decrease in reflectance in the infrared region of 850 to 950 nm was confirmed.
[Examples 6 to 8] and [Comparative Examples 5 to 8] Inkjet ink Inkjet inks having the composition shown in Table 4 were prepared in the same manner as in Example 5.

[Description of raw material name of inkjet ink]
Near-infrared absorbing material (1): near-infrared absorbing material P-2 of Production Example 2
Near-infrared absorbing material (2): near-infrared absorbing material P-3 of Production Example 3
Near-infrared absorbing material (3): MIR-101 manufactured by Midori Chemical Co., Ltd.
Near-infrared absorbing material (4): e-color IR-12 manufactured by Nippon Shokubai Co., Ltd.
Ketone resin: Polyketone resin K-1717 manufactured by LAWTER (hydroxyl value 270, softening point 100 ° C.)
PVP resin: P-15 K-15 manufactured by ISP (weight average molecular weight 6000 to 15000)
TBAB: Tetrabutylammonium bromide Silicone additive: Nihon Unicar FZ2123
The ink jet inks obtained in Examples and Comparative Examples were evaluated as follows. The results are shown in Table 5.

〔Evaluation methods〕
Viscosity: Measured with an E-type viscometer (25 ° C) manufactured by Toki Sangyo Co., Ltd. Dot shape: The shape of the dot on the PET film was confirmed with a microscope.

          ○: A beautiful circular dot is formed.

          (Triangle | delta): Although it is a circular state, mist has generate | occur | produced around.

          ×: A large amount of mist is generated, and the dot shape is indefinite.

  Spectral reflectance: According to the evaluation method of lithographic ink.

  Stealth property: The dot on PET film was confirmed visually.

          ○: Almost invisible.

          Δ: Coloring is slightly confirmed.

          X: Coloration is clearly confirmed.

    Ink-jet inks of Comparative Examples 5 and 7 have poor solubility of the near-infrared absorbing material, and the dot shape is disturbed due to lack of ink-jet suitability. Also, the spectral reflectance was insufficient.

The ink jet inks of Comparative Examples 6 and 8 had sufficient spectral reflectance, but their solubility was extremely inferior, resulting in lack of ink jet suitability and insufficient dot shape. Moreover, since the coloring is strong and can be easily recognized visually, the stealth performance is insufficient.
[Example 9] (Toner Example)
Binder resin Styrene-butyl acrylate copolymer resin (Tg = 63 ° C.) 90 parts by weight Near infrared absorbing material P-1 6 parts by weight Charge control agent Quaternary ammonium salt compound (Bontron P-51) 2 parts by weight wax Low 2 parts by weight of molecular weight polypropylene (Biscol 550P) was mixed, kneaded, pulverized and classified to obtain toner base particles (classified toner) having an average particle size of 8 μm. With respect to 100 parts of the toner base particles and 100 parts of the toner base particles, 0.3 parts of commercially available positively charged hydrophobic silica (Nippon Aerosil Co., Ltd. RA200HS), conductive tin oxide fine powder (T-1 manufactured by Mitsubishi Materials Corporation) 0.3 part of the mixture was mixed with a Henschel mixer, sieved using a vibrating sieve to remove foreign matters, and invisible toner 1 was obtained.
(Image test)
4 parts of the obtained invisible toner and 96 parts of a silicone resin-coated ferrite carrier having an average particle diameter of 100 μm were mixed using a ball mill to prepare a developer. Next, using this developer and toner, a live-action test was performed using a commercially available copying machine SF-2030 manufactured by Sharp Corporation. Specifically, 20 types of gradation patterns were obtained using KODAK GRAY SCALE manufactured by Eastman Kodak Co. as a manuscript. Twenty kinds of gradation patterns have an original image density of 0.04 to 1.85 in Macbeth RD918. Among these, OD = 0.04 (position A), 0.15 (position 1), 1.15. Image density measurements for (11 position) and 1.84 (19 position) were similarly performed on Macbeth RD918. Any position could not be recognized visually, and the image density of all four points was 0.07.

  Furthermore, the spectral reflection spectrum was measured for the portion of the original density (OD) = 1.84. A printed matter having a reflectance of 35% at 870 nm, being detectable with high sensitivity by a near-infrared sensor, and difficult to identify visually was obtained. The results are shown in Table 6.

  The copy paper used was a color application paper Ncolor127 (127.9 g / m2) A4 size manufactured by Fuji Xerox.

The spectral reflectance was measured under the same conditions as those for the ink.
[Comparative Example 9]
Binder resin Styrene-butyl acrylate copolymer resin (Tg = 63 ° C.) 92 parts by weight Near-infrared absorbing material P-1 6 parts by weight wax Low molecular weight polypropylene (Biscol 550P) 2 parts by weight are blended, kneaded, pulverized and classified Thus, toner base particles (classified toner) having an average particle diameter of 8 μm were obtained. With respect to 100 parts of the toner base particles and 100 parts of the toner base particles, 0.3 parts of commercially available positively charged hydrophobic silica (Nippon Aerosil Co., Ltd. RA200HS), conductive tin oxide fine powder (T-1 manufactured by Mitsubishi Materials Corporation) 0.3 part of the mixture was mixed with a Henschel mixer, sieved using a vibration sieve to remove foreign matters, and invisible toner 2 was obtained.

Image tests and evaluations were performed in the same manner as in Example 9. The results are shown in Table 6.
[Example 10]
Evaluation was performed in the same manner as in Example 9 except that the addition amount of the near-infrared absorbing material P-1 was changed from 6 parts by weight to 4 parts by weight and the addition amount of the binder resin was changed from 90 parts by weight to 92 parts by weight. The results are shown in Table 6.

Synthesis Example 1 Synthesis of Urethane Resin 1000 parts of poly (1,2-propylene adipate) glycol (number average molecular weight 2000) in a four-necked flask equipped with a stirrer, thermometer, reflux condenser, and nitrogen gas introduction tube 222 parts of isophorone diisocyanate was charged and allowed to react at 100 ° C. for 5 hours in a nitrogen atmosphere to obtain a prepolymer solution of 3.36% of free isocyanate, and 815 parts of methyl ethyl ketone was added thereto to obtain a urethane prepolymer solution. Next, 2037 parts of the urethane prepolymer solution was added to a mixture comprising 88.7 parts of isophoronediamine, 1244 parts of methyl ethyl ketone and 1019 parts of isopropyl alcohol at room temperature, and further stirred for 30 minutes, and then heated to 40 ° C. for 5 hours. I let you. The urethane resin thus obtained had a solid content of 30%.

Disperse and homogenize 200 parts of the urethane resin obtained in Synthesis Example 1, 5 parts of the near-infrared absorbing material (P-1) produced in Production Example 1, 20 parts of toluene and 20 parts of isopropyl alcohol with a paint conditioner, and gravure A printing ink (1) was obtained. The obtained printing ink was further diluted with a mixed solvent of toluene and isopropyl alcohol (weight ratio 70:30), and adjusted to 15 seconds (25 ° C.) with Zahn Carp # 3 (manufactured by Kogaisha) to obtain a printing ink. Gravure printing ink (1) is printed on corona discharge-treated PET (“Ester E5102” manufactured by Toyobo Co., Ltd., film thickness 12 μm) on the processing surface side using a gravure plate with a line and plate depth of 35 μm, and printing speed with a small calibrator. Printing was performed at 50 m / min and a drying temperature of 60 ° C.

  Spectral reflectance: According to the evaluation method of lithographic ink.

  The spectral reflectance was 38% at 870 nm.

According to the present invention, the dispersibility in the ink vehicle and the kneadability are good, there is no aggregation over time in the vehicle, the printability and storage stability are excellent, and the heat, light, chemical resistance, etc. are excellent, and identification with the naked eye However, a near-infrared absorbing ink composition that gives a printed matter that is not easy to obtain can be obtained.

Claims (11)

An ink composition comprising a near-infrared absorbing material having a repeating unit represented by the following general formula (1).
General formula (1):
(In the formula, M represents a metal atom, any one of R ^{1 to} R ²⁰ represents a direct bond, the other represents a divalent group represented by the following general formula (2), and the rest Each independently represents a hydrogen atom or a substituent.)
General formula (2):
(In the formula, X ^{1 to} X ⁴ are a direct bond or —NHCO—, —CONH—, —NHCOO—, —OCONH—, —O—, —S—, —COO—, —OCO—, —SO ₂ —, — CO—, —C═C—, —N═N—, —SS—, represents a substituted or unsubstituted imino group, Ar ¹ and Ar ² represent a direct bond or a substituted or unsubstituted arylene group or a substituted or unsubstituted Represents an unsubstituted heteroarylene group, n represents a natural number, Y represents a direct bond or an unsubstituted alkylene group, —NHCO—, —CONH—, —NHCOO—, —OCONH—, —O—, —S—, —NH—, —COO—, —OCO—, —SO ₂ —, —CO—, —C═C—, —N═N—, —SS—, a substituted imino group or the following divalent organic residue Represents.)
Any one of R ^{1 to} R ¹⁰ of the near-infrared absorbing material is a direct bond, and any one of R ^{11 to} R ²⁰ is a divalent group represented by the general formula (2). The ink composition according to claim 1. Any one of R ^{1 to} R ⁵ of the near-infrared absorbing material is a direct bond, and any one of R ^{6 to} R ¹⁰ is a divalent group represented by the general formula (2). The ink composition according to claim 1. One of R ^{1 to} R ⁵ of the near-infrared absorbing material is a direct bond, and the other one of R ^{1 to} R ⁵ is a divalent group represented by the general formula (2). The ink composition according to claim 1.   The ink composition according to claim 1, wherein the near-infrared absorbing material is a homopolymer having a repeating unit represented by the general formula (1).   The ink composition according to any one of claims 1 to 4, wherein the near-infrared absorbing material is a copolymer having two or more kinds of repeating units represented by the general formula (1) as repeating units.   The ink composition according to any one of claims 1 to 6, wherein the benzene ring to which the divalent group represented by the general formula (2) is not bonded has a substituent at the ortho position of the near-infrared absorbing material. .   The ink composition according to any one of claims 1 to 7, wherein the ink composition is a lithographic ink.   The ink composition according to any one of claims 1 to 7, wherein the ink composition is an electrostatic charge image developing toner.   The ink composition according to claim 1, wherein the ink composition is an ink jet ink. The ink composition according to any one of claims 1 to 7, wherein the ink composition is a gravure ink.