JP2014012843A - Ink composition containing c.i.pigment yellow 74 - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an ink composition containing C.I.PIGMENT YELLOW 74 (hereinafter referred to as PY-74) that has excellent light fastness and does not cause discharge failure.SOLUTION: In the ink composition containing at least PY-74 as a colorant, the content of an anisidide compound as given below as a by-product of the PY-74 is 1-20 ppm.

Description

Background of the Invention

FIELD OF THE INVENTION This invention relates to C.I. I. In particular, the ink composition containing CI Pigment Yellow 74 has excellent light resistance and does not cause ejection failure. I. The present invention relates to an ink composition containing Pigment Yellow 74.

Background Art Since pigment-based inks using pigments as colorants are generally insoluble in water, they are required to stably disperse pigments to prevent sedimentation and to have good long-term stability over time.

  For example, in the republished 2003-97533 (Patent Document 1), in order to eject ink droplets from fine nozzles, a process of finely dispersing the pigment and further sufficiently adsorbing the polymeric dispersant to the pigment is performed. There has been reported a pigment dispersion that is excellent in dischargeability and excellent in stability over time.

  C.I. as a yellow pigment used in ink jet recording inks. I. Pigment Yellow 74 is known. This pigment is C.I. I. Pigment yellow 110 and C.I. I. Compared to other yellow pigments such as CI Pigment Yellow 128, there is a problem in that it is inferior in light resistance, although it is excellent from the viewpoint of color developability.

  For this light resistance problem, C.I. I. It is known that light resistance is improved by increasing the primary particle size by controlling the reaction temperature in the production process of Pigment Yellow 74 and making the particle size uniform. JP-A-5-70725 (Patent Document 2) discloses C.I. I. In Pigment Yellow 74, it is disclosed that various fastnesses such as light resistance are improved by replacing a part of specific components having different substituents and performing a surface treatment such as rosin.

  Further, from the viewpoint of light resistance, C.I. I. It is known that the light resistance is improved by setting the reaction temperature to 50 ° C. or higher and making the pigment particle size uniform in the production process of CI Pigment Yellow 74. I. Ink using CI Pigment Yellow 74 may have a problem with ejection properties.

Republished No. 2003-97753 JP-A-5-70725

  The inventors of the present invention have recently used C.I., which has been coupled with m-nitro-o-anisidine and acetoacetic acid-o-anisidide at 50 ° C. or higher as a yellow pigment. I. When Pigment Yellow 74 is used, the ink is clogged in the ink flow path, and ink ejection failure may occur. The cause of this ejection failure is C.I. I. It was found that the aniside compound, which is a by-product during the synthesis of Pigment Yellow 74, is precipitated in the ink flow path.

  In addition, by setting the content of the aniside compound contained in the ink composition within a specific range, C.I. I. It was found that an ink composition containing Pigment Yellow 74 was obtained. The present invention is based on this finding.

  Therefore, an object of the present invention is to provide C.C. I. It is to provide a pigment yellow 74-containing ink composition.

および／または下記式：

で表されるアニシダイド化合物の含有量が１〜２０ｐｐｍである。 The ink composition according to the present invention includes C.I. I. Pigment Yellow 74, which is an ink composition comprising at least C.I. I. The following formula (I), which is a by-product of Pigment Yellow 74:

And / or the following formula:

The content of the anisido compound represented by 1 to 20 ppm.

  According to the present invention, by setting the content of the aniside compound represented by formula (I) and / or formula (II) in the ink composition to a predetermined amount, the ink composition has excellent light resistance and does not cause ejection failure. C. I. Pigment Yellow 74-containing ink composition can be realized.

Detailed description of the invention

  The ink composition according to the present invention includes C.I. I. An ink composition comprising CI Pigment Yellow 74. Hereinafter, each component of the ink composition according to the present invention will be described.

Colorant The ink composition according to the present invention contains C.I. I. Pigment Yellow 74 is used. This C.I. I. Pigment Yellow 74 is usually obtained by coupling reaction of m-nitro-o-anisidine and acetoacetic acid-o-anisidide. Specifically, a diazotization reaction of m-nitro-o-anisidine is performed, a solution of acetoacetic acid-o-anisidide is mixed in this reaction solution, and a coupling reaction is performed. I. Pigment Yellow 74 can be synthesized.

  In the present invention, during this coupling reaction, C.I. I. As a by-product of Pigment Yellow 74, it was found that a cyclic trimer of acetoacetic acid-o-anisidide was formed, and this by-product crystallized and precipitated in the ink composition. I. It has been found that the ink composition using Pigment Yellow 74 is a cause of ejection failure and clogging.

C. I. Cyclic trimer of acetoacetic acid-o-anisidide, which is a by-product during the synthesis of Pigment Yellow 74 (hereinafter also referred to as anisidide compound), has the following two types of chemical structures (I) and (II). doing.

  In the present invention, by setting the content of this aniside compound in the ink composition to 1 to 20 ppm, C.I. is excellent in light resistance and does not cause ejection failure. I. Pigment Yellow 74-containing ink composition can be realized.

Examples of the method for quantifying the content of the aniside compound in the ink composition include high performance liquid chromatography (hereinafter also referred to as HPLC). The area of the specific peak derived from the aniside compound under the following quantification conditions: It can be quantified by area.
High-performance liquid chromatography quantitative conditions:
・ Analyzer: HPLC (manufactured by Shimazu)
・ Column: TOSOH
・ Detector: UV254nm
・ Flow rate: 0.7 ml / min ・ Eluent: Acetonitrile: Ion exchange water: Acetic acid = 500: 500: 0.1

  In order to adjust the content of the aniside compound in the ink composition to 1 to 20 ppm, C.I. I. This can be achieved by purifying the pigment yellow 74 by decantation, ultrafiltration, or the like, and removing the crystallized anisidide compound.

  In addition, C.I. I. By controlling the coupling reaction temperature during the synthesis of CI Pigment Yellow 74, the content of the aniside compound as a by-product can be controlled within the above range. C. I. The hue of CI Pigment Yellow 74 is usually adjusted by the coupling reaction temperature between m-nitro-o-anisidine and acetoacetic acid-o-anisidide. C. I. In order to bring the hue of Pigment Yellow 74 within the desired range, the temperature of the coupling reaction needs to be 50 ° C.

  In the present invention, it has been found that the coupling temperature and the content of the by-product anisidide compound are closely related. That is, it has been found that by performing the coupling reaction at a temperature lower than the usual coupling temperature (50 ° C.), the formation of an aniside compound is suppressed. Specifically, by setting the coupling temperature to 30 ° C. or less, the content of the anisido compound in the ink composition can be set to 1 to 20 ppm. However, when the coupling temperature is lowered, the L * and b * values hardly change when displayed in the L * a * b * color system in the hue of the resulting pigment, but the a * value increases. As a result, the color becomes reddish and deviates from the desired color (that is, the range in which the a * value is −1 to 10). In order to obtain a desired color, the coupling temperature is preferably 30 to 50 ° C. Or the dispersion | distribution time can be increased, the shift to redness can be suppressed, and a desired color can also be maintained. For example, C.I. I. Even when Pigment Yellow 74 is synthesized, it can be prepared in a desired color without reddish by performing the pigment dispersion step for a longer time than usual.

Ingredients other than colorant The ink composition according to the present invention comprises the above yellow pigment as a colorant. In addition to the colorant, water, a water-soluble organic solvent, a wetting agent, a polymer dispersant, an interface Activators and other various additives can be included.

  In the present invention, the colorant is preferably contained in the range of about 1 to 10% by weight based on the whole ink.

  The solvent of the ink composition according to the present invention is preferably composed of water and a water-soluble organic solvent. As the water, pure water such as ion exchange water, ultrafiltration water, reverse osmosis water, distilled water, or ultrapure water can be used. In addition, the use of water sterilized by ultraviolet irradiation or addition of hydrogen peroxide is preferable because generation of mold and bacteria can be prevented when the ink composition is stored for a long period of time.

  The water-soluble organic solvent is preferably a low-boiling organic solvent, and examples thereof include methanol, ethanol, n-propyl alcohol, iso-propyl alcohol, n-butanol, sec-butanol, tert-butanol, iso- Examples include butanol and n-pentanol. A monohydric alcohol is particularly preferable. The low boiling point organic solvent has an effect of shortening the drying time of the ink. The amount of the low-boiling organic solvent added is preferably from 0.5 to 10% by weight of the ink, more preferably from 1.5 to 6% by weight.

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

  The amount of these wetting agents added is preferably 0.5 to 40% by weight of the ink, more preferably 2 to 20% by weight.

  The ink composition according to the present invention preferably contains a polymer dispersant. Examples of the polymer dispersant include natural polymers. Specifically, proteins such as glue, gelatin, casein, albumin, natural rubbers such as gum arabic and tragacanth, glucosides such as saponin, alginic acid and propylene glycol alginate, triethanolamine alginate, alginic acid derivatives such as ammonium alginate, etc. , Cellulose derivatives such as methylcellulose, carboxymethylcellulose, hydroxyethylcellulose, and ethylhydroxycellulose. Furthermore, preferred examples of the polymer dispersant include synthetic polymers such as polyvinyl alcohols, polyvinyl pyrrolidones, polyacrylic acid, acrylic acid / acrylonitrile copolymers, potassium acrylate / acrylonitrile copolymers, vinyl acetate / acrylic. Acid ester copolymers, acrylic resins such as acrylic acid / acrylic ester copolymers, styrene / acrylic acid copolymers, styrene / methacrylic acid copolymers, styrene / methacrylic acid / acrylic acid ester copolymers, Styrene-acrylic resin such as styrene / α-methylstyrene / acrylic acid copolymer, styrene / α-methylstyrene / acrylic acid / acrylic acid ester copolymer, styrene / maleic acid copolymer, styrene / maleic anhydride copolymer Polymer, vinyl naphthalene / acrylic acid copolymer , Vinyl naphthalene / maleic acid copolymer, and vinyl acetate / ethylene copolymer, vinyl acetate / fatty acid vinyl / ethylene copolymer, vinyl acetate / maleic acid ester copolymer, vinyl acetate / crotonic acid copolymer, Examples thereof include vinyl acetate copolymers such as vinyl acetate / acrylic acid copolymers and salts thereof. Among these, a copolymer of a monomer having a hydrophobic group and a monomer having a hydrophilic group, and a polymer comprising a monomer having both a hydrophobic group and a hydrophilic group in the molecular structure, such as styrene / acrylic An acid copolymer, a styrene / methacrylic acid copolymer, and the like are preferable.

  The ink composition according to the present invention may further contain a surfactant. Surfactants include anionic surfactants (for example, sodium dodecyl benzene sulfonate, sodium laurate, ammonium salt of polyoxyethylene alkyl ether sulfate), nonionic surfactants (for example, polyoxyethylene alkyl ether) , Polyoxyethylene alkyl esters, polyoxyethylene sorbitan fatty acid esters, polyoxyethylene alkyl phenyl ethers, polyoxyethylene alkyl amines, polyoxyethylene alkyl amides, etc.) and acetylene glycols (olefin Y and Surfinol 82, 104, 440) 465, and 485 (all manufactured by Air Products and Chemicals Inc.), organosiloxane surfactants (BYK347 and 348 (all manufactured by BYK Chemie)), Phosphate ester surfactants (phosphanol RS-410, RS-610, RS-710 (all manufactured by Toho Chemical Co., Ltd.)) can be mentioned. These can be used alone or in combination of two or more.

  In the present invention, an appropriate amount of pigments and / or dyes other than the above-described colorants can be added.

  The ink composition according to the present invention may further contain a nozzle clogging preventive agent, an antiseptic, an antioxidant, a conductivity adjusting agent, a pH adjusting agent, a viscosity adjusting agent, a surface tension adjusting agent, an oxygen absorber, and the like. it can.

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

  Furthermore, examples of pH adjusters, solubilizers or antioxidants include amines such as diethanolamine, triethanolamine, propanolamine, morpholine and their modified products, potassium hydroxide, sodium hydroxide, lithium hydroxide, etc. Inorganic salts, ammonium hydroxide, quaternary ammonium hydroxide (tetramethylammonium, etc.), carbonates such as potassium carbonate, sodium carbonate, lithium carbonate and other phosphates, or N-methyl-2-pyrrolidone, urea, thiourea And L-ascorbic acid and salts thereof, such as ureas such as tetramethylurea, allophanates such as allophanate and methylallohanate, biurets such as biuret, dimethylbiuret and tetramethylbiuret.

  In addition, the ink composition according to the present invention may contain an antioxidant and an ultraviolet absorber. Examples thereof include Tinuvin 328, 900, 1130, 384, 292, 123, 144, 622, and 770 of Ciba-Geigy Corporation. 292, Irgacor 252 153, Irganox 1010, 1076, 1035, MD1024, lanthanide oxide, and the like.

  The ink composition according to the present invention can be produced by dispersing and mixing each of the above components by an appropriate method. Preferably, the pigment, polymer dispersant, and water are first used in a suitable dispersing machine (for example, ball mill, sand mill, attritor, roll mill, agitator mill, Henschel mixer, colloid mill, ultrasonic homogenizer, jet mill, ang mill, etc.). Mix to prepare a uniform pigment dispersion, then add separately prepared resin (resin emulsion), water, water-soluble organic solvent, sugar, pH adjuster, preservative, fungicide, etc. An ink solution is prepared. After sufficiently stirring, the target ink composition can be obtained by performing filtration in order to remove the coarse particle diameter and foreign matters that cause clogging.

  According to the present invention, there is provided a recording method for forming an image on a recording medium using the ink composition described above. In particular, the ink composition according to the present invention is preferably used in a recording method using an inkjet recording method. By using the above-described colorant, even in the ink jet recording method, there is no clogging of the ink flow path such as the nozzle, and ejection failure is reduced.

  EXAMPLES Hereinafter, the present invention will be specifically described by way of examples, but these do not limit the scope of the present invention.

  In the examples, parts and% are based on weight unless otherwise specified.

C. I. Preparation of Pigment Yellow 74 (PY74) (1) Preparation of Colorant (PY74-1) 70.4 parts of m-nitro-o-anisidine was dissolved and stirred in a solution consisting of 600 parts of water and 128 parts of 35% hydrochloric acid. Cooled to 0 ° C. Further, 30.3 parts of sodium nitrite was added, and the mixture was stirred for 1 hour while maintaining at 5 ° C. or less to obtain a diazotized component. On the other hand, 90 parts of acetoacetic acid-o-anisidide was dissolved in a solution consisting of 2300 parts of water and 18 parts of sodium hydroxide. To this, 16 parts of 90% acetic acid was added and precipitated, and then 85 parts of sodium acetate was added to form a coupling component. The diazo component was added to the coupling component over 3 hours. The reaction during this period was kept at 30 ° C. ^{* 1} . After the coupling was completed, 15 parts of rosin was added for surface treatment. The obtained pigment slurry was washed with filtered water, further decanted and squeezed to obtain 367 parts of a wet cake having a pigment (PY74-1) content of 45%.

(2) Preparation of colorant (PY74-2) A colorant was prepared in the same process as above except that the reaction temperature was 50 ° C., to obtain PY74-2.

(3) Preparation of colorant (PY74-3) A colorant was prepared in the same process as described above except that the reaction temperature was 5 ° C to obtain PY74-3.

表中、
PY 74は、C.I.ピグメントイエロー74を表し、
顔料分散剤は、スチレン−アクリル酸樹脂を表し、
1,2-HDは、１，２−ヘキサンジオールを表し、
TEAは、トリエタノールアミンを表し、
BYK348は、オルガノシロキサン系界面活性剤（ビックケミー製）を表す。 Preparation of Ink Composition Each ink composition shown in Table 1 below was prepared. Specifically, the pigment obtained above and a dispersant were mixed and dispersed with a glass bead having a diameter of 0.5 mm for 2 hours in a sand mill. Thereafter, the glass beads were removed to remove coarse particles, followed by filtration with a 10 μm membrane filter to obtain ink compositions 1 to 7 of Examples. In addition, the unit of the addition amount of each component described in Table 1 is “% by weight” unless otherwise specified. The color material concentration (solid content) in the ink composition was 3%.

In the table,
PY 74 represents CI Pigment Yellow 74
The pigment dispersant represents a styrene-acrylic acid resin,
1,2-HD represents 1,2-hexanediol,
TEA represents triethanolamine,
BYK348 represents an organosiloxane surfactant (manufactured by BYK Chemie).

Evaluation (1) Storage stability evaluation (clogging alternative evaluation)
After the ink composition was prepared as described above, the ink was allowed to stand at 60 ° C. for 1 day or longer, and then passed through a 10 μm filter. The presence or absence of foreign matter was confirmed by observing the filter surface with an optical microscope.

  The one where no aniside compound was confirmed was marked with ◯, and the one confirmed was marked with x. The evaluation results were as shown in Table 2 below. In addition, when printing by an ink jet printer was performed using an ink composition having this evaluation of x, ejection failure (clogging) occurred.

(2) Light fastness evaluation The ink jet printer EM-930C (manufactured by Seiko Epson Corporation) was loaded with the ink filled with each ink composition. Using this printer, printing was performed on PM photographic paper (manufactured by Seiko Epson Corporation).

  The print duty was adjusted so that the OD value was 1.0, and a 10 mm × 10 mm color patch was printed. The printing resolution was 720 × 720 dpi.

  Light irradiation is performed using a xenon weatherometer Ci-5000 (manufactured by ATLAS), on the sample under the conditions of an illuminance of 105 W / G (300 to 400 nm = about 150,000 lux), a temperature of 24 ° C., and a humidity of 60%. An air layer and 2 mm thick soda lime glass were installed.

OD values after 400 hours and 600 hours after irradiation were measured using a spectrophotometer GRETAGSPM100 (manufactured by GRETAG), and the OD value retention was evaluated according to the following criteria.
A: The OD value remains 70% or more from the initial stage.
B: An OD value of 50% or more and less than 70% remains with respect to the initial stage.
C: The OD value is less than 50% of the initial value.

  The conditions for the above evaluation were the light source D50, no light source filter, white standard as absolute white, and viewing angle of 2 °.

The evaluation results were as shown in Table 2.

Claims (5)

As a coloring agent, C.I. I. Pigment Yellow 74, which is an ink composition comprising at least C.I. I. A by-product of Pigment Yellow 74, the following formula:

And / or the following formula:

The ink composition whose content of the anisidide compound represented by these is 1-20 ppm.   C. above. I. The ink composition according to claim 1, wherein Pigment Yellow 74 is obtained by a coupling reaction of m-nitro-o-anisidine and acetoacetic acid-o-anisidide.   The ink composition according to claim 1 or 2, wherein the colorant is contained in an amount of 1 to 10% by weight based on the whole ink composition.   An ink-jet recording method for performing printing by discharging droplets of an ink composition and attaching the droplets to a recording medium, wherein the ink composition according to any one of claims 1 to 3 is used as the ink composition. An ink jet recording method using   A recorded matter recorded by the inkjet recording method according to claim 4.