JPH10319640A - Colorant composition, its production, electrophotographic dry and wet developers and in colorant for ink jet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a colorant compsn. contg. a dye having satisfactory dispersability and polarity controllability by using a dye represented by a specified structural formula as the colorant of a developer. SOLUTION: This colorant compsn. contains a dye represented by the formula and a resin. In the formula, R<1> is -COO- or -SO3 -, R<2> -R<6> and R<9> -R<12> are -H, -Cn H2n+1 [(n) is an integer of 1-12], halogen, -NO2 or -NH2 , R<4> and R<7> are -OH, -COOH or -SO3 H, R<8> is -SO3 - or-COO and M is Zn, Ni, Sr, Ba, Fe, etc. The resin is a polyolefin or a polyolefin copolymer. The dye content is 2-80 wt.% and the resin content is 20-98 wt.%. A dry electrophotographic developer using the colorant compsn. gives a clear image. A wet electrophotographic developer using the colorant compsn. ensures high image density and high color reproducibility of a copy and improves the transparency of a toner layer.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a colorant composition, a method for producing the same, and a dry or wet developer for electrophotography and an ink colorant for ink jet.

[0002]

2. Description of the Related Art In the case where an electrostatic latent image formed by an electrophotographic method such as an electrophotographic method or an electrostatic recording method is visualized by a wet developing method, a liquid developer is used. A liquid developer consists of a colorant or a resin called a toner in a highly insulating and low dielectric constant organic solvent generally called a carrier liquid, which is a dispersion stabilizer consisting of surfactants such as naphthenic acid metal salt and lecithin. It is dispersed together with a control agent. During use or storage of the developer, the toner in the developer is required to be stably dispersed.

The coloring agents used for coloring such toners include inorganic pigments such as carbon black, phthalocyanine blue, sky blue, rhodamine lake, malachite green lake, methyl violet lake, peacock blue lake, and naphthol. Green B, Naphthol Green Y, Naphthol Yellow S,
Organic pigments such as Permanent Red 4R, Brilliant Fast Scarlet, Hansa Yellow and Benzidine Yellow are known.

However, since many of these pigments have poor dispersibility and do not themselves have polarity controllability, liquid developers using these pigments have
When used or stored for a long period of time, the dispersion stabilizer and the polarity control agent are taken into the carrier liquid, and the dispersion stabilizer and the polarity control agent do not lose their functions. The missing toner has a drawback that it causes aggregation or insufficient polarity, resulting in deterioration of image quality.

[0005] In order to improve such disadvantages, it has been proposed to apply a surface treatment so that the pigment is well blended, or to use carbon black to graft the carbon black to impart dispersibility and polarity controllability. However, satisfactory results have not yet been obtained. In addition, conventional colorants are inferior in transparency and tinting strength, and are not satisfactory for color toners.

JP-B-58-9418 discloses a liquid developer for electrostatography containing a thioingoid pigment. The thioindigo pigment can be used as a full-color magenta toner, but in this case, the redness is weak and the spectral characteristics are not preferable for magenta.
Also, JP-A-49-99033, JP-A-49-134
No. 333, JP-A-46-1636, etc.
₂ and a toner in which a resin is dyed with a dye have also been proposed. However, these liquid toners have a problem that the coloring power is weak and the image density is low.

When a dye is used in a dry developer for electrophotography, the dye is dispersed in a resin dispersion medium together with other additives, if necessary, and then the resin is finely pulverized.
The surface of the resin particles obtained by crushing is inevitably affected by the contained dye. In particular, when a pigment is used as a pigment, crushing occurs at the interface between the pigment and the resin, and in this case,
The surface of the pigment may be exposed on the surface of the crushed particles. Further, in a developer for an electrophotographic copying machine, a dye used in the developer is also limited depending on a required hue and color tone of a copied image.

Therefore, when the amount of the dye which is positively charged by the friction of the electrophotographic developer with the carrier is small, and the dye selected from the required hue of the copied image is positively charged upon the friction with the carrier, , In terms of the chargeability of minute portions on the surface of the developer particles and the chargeability between each particle,
There is a problem of lack of uniformity.

[0009]

SUMMARY OF THE INVENTION An object of the present invention is to provide a colorant composition containing a dye and a resin, a colorant composition having a good dispersibility and good polarity controllability, a method for producing the same, and coloring. An object of the present invention is to provide a dry and wet developer for electrophotography and an ink colorant for inkjet using the composition.

[0010]

Means for Solving the Problems In view of the above-described defect of the developer of the electrostatic latent image, the present inventors have conducted various studies on the structure of the dye in order to satisfy the above conditions. It has been found that by using the dye represented by the formula (1) as a colorant for a developer, excellent effects can be exhibited even under the above-mentioned conditions, and the present invention has been completed.

According to the present invention, first, there is provided a colorant composition containing at least a dye and a resin, wherein the dye is a dye represented by the general formula (1). You.

Embedded image

According to the present invention, secondly, the first colorant composition is provided, wherein the resin is selected from a polyolefin and a polyolefin copolymer. Third, the content of the pigment is 2 to 80 wt%
The first colorant composition is provided, wherein the content of the resin is 20 to 98 wt%. Fourth,
After dissolving the first dye in water, add a resin solution,
The present invention provides a method for producing a colorant composition, which comprises stirring and mixing, separating water, drying and pulverizing a resin solution containing a remaining dye. Fifth, there is provided a dry developer for electrophotography, wherein the first colorant composition is used for a dry developer for electrophotography. Sixth, there is provided an electrophotographic wet developer, wherein the first colorant composition is used in an electrophotographic wet developer. Seventh, there is provided an ink-jet ink colorant characterized by using the first colorant composition as an ink-jet ink colorant.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, a dye represented by the following general formula (1) is used.

Embedded image The dye represented by the general formula (1) used in the present invention is a known substance of red / magenta type and can be easily obtained. Table 1 shows typical compounds.

[0014]

[Table 1]

In order to obtain the colorant composition of the present invention by a flushing method, a colorant (pigment) is dissolved in water to form a water-containing liquid.
Further, a resin dispersion medium is added and mixed well in a kneader called a flasher. By this operation, water existing around the pigment is replaced by a resin dispersion medium added later. The water taken out by this operation is discharged, the pigment is dispersed in the resin solution and dried, and the solvent is removed to obtain the remaining lump. Then, the mass is pulverized to obtain a colorant powder. The coloring agent is obtained by coating a pigment with a resin, and can be used for printing inks, paints, toners for electrophotography, and the like.

When the resin is dispersed in an aqueous solution containing the dye of the general formula (1), any conventional resin dispersion medium can be used as the resin dispersion medium. For example, polystyrene, styrene- (meth) acrylate copolymer, styrene-maleate copolymer, (meth) acrylate polymer and copolymer, styrene-diene copolymer, polyethylene, polypropylene, Modification of addition polymerization resins such as ethylene-vinyl acetate copolymer and ethylene-acrylate copolymer, condensation resins such as polyester resins, epoxy resins and phenolic resins, rosin esters and maleated rosin esters Resins, petroleum resins, higher fatty acid waxes, higher alcohols, higher fatty acids, paraffin waxes, low molecular solids such as carnauba wax, shellac and the like can be used alone or in combination. Among these, polyethylene, polypropylene, polyolefins such as ethylene-acrylate copolymers, ethylene-maleic anhydride copolymers, polyolefin copolymers have good dispersibility, and good results are obtained .

A production example of the colorant composition is as follows (hereinafter referred to as Production Example A). 50 parts by weight of water and 20 parts by weight of “Dye Compound No. 2” in Table 1 were taken with a flasher and mixed and dispersed well. Next, an ethylene-vinyl acetate copolymer (Eva Flec 210, manufactured by Mitsui DuPont) 80
Parts by weight and 50 parts by weight of toluene were added and dispersed at 100 ° C. for 2 hours. After dispersion, the pressure was reduced, water and toluene were removed, and the mixture was pulverized to obtain a flushing colorant.

The content of the coloring matter in the resin solution containing the coloring matter represented by the general formula (1) and the coloring composition containing other additives is different depending on the purpose of use. Solids containing high concentrations of dyes such as printing inks and paints,
In a paste or liquid composition, the pigment concentration is about 80% to 10% by weight, preferably 60% by weight to
The colorant composition of the dry developer for electrophotography has a pigment concentration of about 15% to 2% by weight, preferably 10% to 3% by weight.

In the case of producing a dry developer for electrophotography, a high-concentration dye is contained, thoroughly mixed and dispersed, the color tone is adjusted, and then a composition having a low concentration of the dye is prepared. To manufacture. The composition having a high concentration of the pigment may be in any form such as a solid such as a coarse particle, a coarse powder, a fine powder, a sheet or a small lump, or a paste or a liquid. The concentration of the dye is determined by the use or condition of the composition used as the final image recording developer, and is a so-called dry developer, wet developer, electrostatic developer, or the like. Is classified into a two-component developer and a one-component developer.

A ferromagnetic material can be used in combination with the one-component dry developer. These ferromagnetic materials are also added as needed to the coloring composition of the present invention, and any of ferromagnetic fine particles conventionally used for magnetic developers can be used. For example, oxides such as triiron tetroxide powder and iron sesquioxide powder, and metal powders such as iron, nickel, and cobalt are not limited to a cubic shape, a needle shape, or the like.

In the pressure fixing type developer, the plasticizing material to be added as necessary is used.
Plasticizers, fats and oils, low-melting waxes, petroleum resins, liquid oligomer resins and the like can be mentioned.

An electrophotographic liquid developer is prepared by dispersing a colorant composition containing a colorant and a resin in a carrier liquid. Examples of the carrier liquid include petroleum resin hydrocarbons having a high insulating property (electric resistance of 10 ¹⁰ Ωcm or more) and a low dielectric constant (dielectric constant of 3 or less), n-hexane, ligroin, n-heptane, n-peptane, isododecane, Other halogen derivatives thereof such as isooctane, for example, carbon tetrachloride, perchlorethylene and the like. Commercial products of the above-mentioned petroleum aliphatic hydrocarbons include Ansoper E, Isopar G, Isopar L, Isopar H, Isopar K, and Naphtha No. 6,
Solvesso 100 and the like. These may be used alone or in combination. Solvents used in pastes or liquid compositions containing high concentrations of dyes include aliphatic hydrocarbons, alicyclic hydrocarbons, aromatic hydrocarbons, halogenated hydrocarbons, esters, and ketones. , Glycol ethers, alcohols, waters and the like are used, and are not particularly limited to specific substances among them. When used as a medium for a wet electrophotographic developer, a conventionally known highly insulating petroleum-based solvent, for example, Isopar H,
Isopar G (above, manufactured by Esso Standard), Shellsol 71 (manufactured by Shell Petroleum), kerosene and the like are used.

When a dye is further required, it is appropriately selected from conventionally known pigments or dyes and used together with the dye used in the present invention. For example, as organic pigments or dyes, phthalocyanine-based, azo-based, anthraquinone-based, perinone-perylene-based, indigo-thioindigo-based, dioxazine-based, quinacridone-based, isoindoline-based, aniline black-based, carbon black-based pigments, and the like. Examples of the inorganic pigments include titanium oxide-based, iron oxide-based, calcined pigment-based, navy blue, metal powder pigments, extender pigments, and the like. When used as an electrophotographic developer, other conventionally known charge control agents, cleaning agents,
An agent for improving the fluidity of the developer can be added.

In the colorant composition of the present invention, the dye represented by the general formula (1) is selected as the dye component. Can be reduced. Even when used as a liquid developer, the interface potential is constant and development can be stably performed for a long time.

[0025]

Next, the present invention will be specifically described with reference to examples. In the following description, “parts” or “%” is based on weight unless otherwise specified.

Example 1 30 parts of "Dye Compound No. 2" in Table 1 were converted to a styrene-methacrylic copolymer (softening point: about 116 ° C., glass transition point: about 59 ° C., GPC weight average molecular weight: about 80,000) 65 The mixture was thoroughly kneaded with a three-roll mill at 100 ° C. to disperse the dye. After cooling, the mixture was crushed to obtain a coarse powder of the colorant composition of the present invention containing the dye at a concentration of 20%. Next, 20 parts of the colorant composition containing the dye obtained by this operation were kneaded with 80 parts of the styrene-methacrylic copolymer used in the usual manner, cooled, pulverized, and then finely pulverized by a jet mill. And
After classification, a fine powder of the colorant composition of the present invention having a size of 5 to 15 μm was obtained. The measured triboelectric charge of this colorant composition was -10.1 μC / gr. Colloidal silica is added as a fluidizing agent to the above magenta resin fine powder and mixed well according to a conventional method to form an electrophotographic dry developer.
When mixed with the magnetic iron component of the carrier, a uniform negative polarity was exhibited. Subsequently, it was subjected to copying by an electrophotographic copying machine for a negative charge developer, and a clear and stable copied image having an image density of 1.28 was obtained.

Example 2 30 parts of the colorant composition containing the dye of Example 1 at a concentration of 20% was added to 100 parts of Isopar H together with 15 parts of an acrylate resin soluble in an aliphatic hydrocarbon solvent, and the mixture was added to a ball mill. For 20 hours to prepare a thick colored liquid. 5 parts of this thick colored liquid was added and dispersed in 1 liter of Isopar H to obtain an electrophotographic wet developer. When this was copied by a wet electrophotographic copying machine, the image density was 1.21.
As a result, the color reproducibility of the OHP was good, and a clear and calm color copy image was stably obtained.

Example 3 Instead of 20 parts of the colorant composition of Example 1, 30 parts of the colorant composition of Production Example A prepared by flushing the coloring matter of the present invention by a flashing method was used. Similarly, when a dry toner was prepared and evaluated, the triboelectric charge was -13.3 μC / gr. The image density was 1.32, indicating a uniform negative polarity, and a clearer image was obtained than in Example 1. Resolution is 7.2
Book / mm.

Example 4 In place of 30 parts of the colorant composition of Example 2, 30 parts of the colorant composition of Production Example A prepared by flushing the dye of the present invention was used. Similarly, when a wet toner was prepared and evaluated, the image density was 1.31, and a deep magenta image could be obtained. The resolution was 9.5 lines / mm.

Example 5 The liquid toners obtained in Examples 2 and 4 could be used as ink-jet inks, paints and printing inks.
The image density of the inkjet ink was higher than that of the conventional aqueous ink, and an image without bleeding was obtained. Since the liquid toner of the present invention has a small particle diameter and a good dispersibility of 0.1 to 0.5 μm, it is possible to form a glossy coating film or printed matter with a gloss even with a paint or a printing ink.

[0031]

According to the dry electrophotographic developer obtained by the present invention, a clear copy can be obtained. Further, according to the developer for wet electrophotography, since the copy image density is high and the color reproducibility is high, the transparency of the toner layer is good. Further, by using a colorant composition produced by a flushing method for a dye in a dry toner or a liquid toner, the effect of increasing the image density of a copy and improving the charge amount can be obtained. The inkjet ink, printing ink, and paint using the colorant of the present invention have high dispersion stability and coloring power.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C09B 45/14 C09B 45/34 45/34 C09D 11/00 C09D 11/00 B41J 3/04 101Y G03G 9/087 G03G 9/08 325 9/12 381 9/12 311 (72) Inventor Aiko Ishikawa 1-3-6 Nakamagome, Ota-ku, Tokyo Inside Ricoh Co., Ltd. (72) Inventor Yukio Tabata 1-3-6 Nakamagome, Ota-ku, Tokyo No. Within Ricoh Co., Ltd. (72) Inventor Shin Ogawara 2-2-1-211 Ookayama, Meguro-ku, Tokyo

Claims (7)

[Claims] 1. A colorant composition comprising a colorant and a resin, wherein the colorant is a colorant represented by the general formula (1). Embedded image 2. The colorant composition according to claim 1, wherein the resin according to claim 1 is selected from a polyolefin and a polyolefin copolymer. 3. The content of the dye of claim 1 is 2 to 80 wt.
%, And the content of the resin is 20 to 98% by weight. 4. A coloring agent comprising dissolving the dye according to claim 1 in water, adding a resin solution, stirring and mixing, separating water, drying and pulverizing the resin solution containing the remaining dye. A method for producing the composition. 5. A dry developer for electrophotography, wherein the colorant composition according to claim 1 is used for a dry developer for electrophotography. 6. A wet developer for electrophotography, wherein the colorant composition according to claim 1 is used in a wet developer for electrophotography. 7. An ink-jet ink colorant, wherein the colorant composition according to claim 1 is used as an ink-jet ink colorant.