JPS6247056A - Coloring composition for image recording - Google Patents

Abstract

PURPOSE:To reduce the variance of electrostatic chargeability among particles, to maintain potential at the interfaces constant, and to enable stable development for a long period by specifying a dye in an image recording coloring composition. CONSTITUTION:The image recording coloring composition is composed of the dye represented by the formula shown on the right and a resin dispersion medium for dispersing the dye, and when the composition is used as the developer, the medium acts as the fixing agent of the dye, and all the media having conventionally been used can been used. The dye is contained in the coloring composition containing said resin dispersion medium and other additives, preferably, in an amount of 60-30wt% of the solid, paste, and liquid composition containing a high concentration of dye, and in the case of using as the colorant of the electrophotographic developer, it is used, preferably, in an amount of 10-3wt%.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a developer for electrostatic latent images in image recording such as electrophotography, electrostatic printing, and electrostatic recording, or a coloring composition used for the production thereof. and a coloring composition used as the image recording developer.

More specifically, in an electrostatic latent image developer containing a dye such as a pigment or dye, various defects caused by the charge and amount of charge brought about by the dye can be avoided by selecting a dye with a specific structure as the dye. It was improved by.

(Prior Art) In general, when pigments such as organic pigments or dyes are rubbed against a carrier used in an electrophotographic developer, various charging properties change depending on their structure. For example, copper phthalocyanine blue pigments, quinacridone pigments, and the like exhibit positive chargeability upon friction with a carrier, while copper phthalocyanine green pigments and the like exhibit negative chargeability.

(Problems to be Solved by the Invention) When a dye is used in a dry developer for an electrophotographic copying machine, the dye is dispersed in a resin dispersion medium along with other additives as necessary, and then finely ground. The surface of crushed particles is unavoidably affected by the pigment used. Particularly when pigments are used, crushing occurs at the interface between the pigment and the resin, and the pigment surface may be exposed on the particle surface.

Furthermore, in a developer for an electrophotographic copying machine, the dye used in the developer is also limited depending on the hue and tone of the required copy image.

Therefore, it requires a negatively charged developer,
In addition, if the dye selected based on the hue of the required copy image is positively charged when it rubs with the carrier,
The defect is that the chargeability of minute portions on the surface of the developer particles and the chargeability between each particle lacks uniformity.

In view of the above-mentioned defects in electrostatic latent image developers, the present inventors conducted various studies on the structure of dyes that satisfy the above conditions. The present invention was completed based on the finding that when used as a coloring agent, excellent effects can be exhibited even under the conditions described above.

(Means for Solving the Problems) That is, the present invention provides a coloring composition for image recording comprising one dye and a resin dispersion medium, wherein the dye is a dye represented by the following structural formula. It is a colored composition.

To explain the present invention in detail, the dye represented by the above structural formula used in the present invention and which mainly characterizes the present invention is:
For example, it can be obtained as follows. (% in sentence
and parts are by weight).

18 parts of Scarlet LG base, 35% according to the usual method
20 parts of hydrochloric acid, 24.6 parts of NaNO, 300 parts of liquid, 0°C
Diazotize under the following conditions.

Next, put 8 parts of naphthol As 17 into 90 parts of water and 6.8 parts of caustic soda and dissolve by heating.The liquid volume is 70 parts.
0 parts, the temperature was set to 10°C, and 1.5 parts of funnel oil was injected. The above-mentioned diazo solution was injected into the solution over a period of about 90 minutes to perform coupling, and the mixture was stirred for 60 minutes. This was adjusted to pH 3 with acetic acid.
After adjusting the temperature to 5 to 4.0, the temperature at the shoulder is set at 90°C. Stir for 5 minutes, press and wash to obtain a pigment cake. This is dried at 100°C and pulverized to obtain a red pigment powder.

The resin dispersion medium used in the present invention is a dispersion medium for the above-mentioned dye, and also acts as a fixing agent for the dye when used as a developer.

All conventionally used resin dispersion media can be used, such as polystyrene, styrene-(meth)acrylic acid ester copolymer, styrene-maleic acid ester copolymer, and (meth)acrylic acid ester copolymer. Addition polymer resins such as acrylic ester polymers and copolymers, styrene-diene copolymers, polyethylene, polypropylene, ethylene-vinyl acetate copolymers, ethylene-acrylic ester copolymers, polyester resins, epoxy m-based resins, phenolic resins, etc., modified resins such as rosin esters, maleated rosin esters, petroleum resins, higher fatty acid waxes, higher alcohols, higher fatty acids, low molecular solids such as paraffin wax, carnauba wax, shellac, etc. etc. can be used alone or in combination.

In the present invention, the content of the pigment represented by the above structural formula in the coloring composition containing the resin dispersion medium and other additives is as follows:
It varies depending on the purpose of use, and in a solid, pasty or liquid composition containing the pigment at a high concentration, about 80% to 10% by weight, preferably 60% to 30% by weight. When used as a coloring agent in an electrophotographic developer, the content is approximately 15% to 2% by weight, preferably 10% to 3% by weight, and the most preferred content is used depending on the purpose. do.

The coloring composition for image recording of the present invention can be used in various ways depending on the purpose.

One example is one that contains pigment at a high concentration and is used to facilitate the subsequent process by thoroughly kneading it in advance to disperse it or toning it.
It can be used in any solid form such as a sheet or small lump, or in a paste or liquid form.

Another example is a composition used as a final image recording developer, so-called dry developer,
These include wet developers, electrostatic developers, etc., and dry developers are also classified into two-component developers and one-component developers.

A ferromagnetic material is mainly used in one-component dry developers. These ferromagnetic materials are also added to the coloring composition of the present invention if necessary, and any of the ferromagnetic fine particles conventionally used for magnetic developers can be used.

For example, oxides such as triiron tetroxide powder and sesquioxide powder, iron,
It is a metal powder such as nickel or cobalt, and the shape is not limited to a cubic shape, a needle shape, etc.

In addition, the plasticizing materials added as necessary are those used in pressure fixing type developers, such as plasticizers, oils and fats, etc.
Examples include low melting point wax, petroleum resin, liquid oligomer resin, etc.

If the solvent is used in a paste or liquid composition containing a high concentration of pigment, depending on the manufacturing process or method of use, aliphatic, alicyclic, aromatic hydrocarbons, halogenated hydrocarbons, etc. Hydrogen, ester-based, ketone-based, glycol ether-based, alcohol-based, water-based, etc. are used, and are not particularly limited.

When used as a wet liquid developer medium, conventionally known highly insulating petroleum solvents such as Isopar H, Isopar G (Esso Standard Co., Ltd.), Shellsol 71 (Shell Oil Co., Ltd.) and Use kerosene etc.

In addition, if additional pigments are required, they can be appropriately selected from conventionally known pigments or dyes and used together with the pigments used in the present invention.For example, as organic pigments or dyes,
Phthalocyanine pigments, azo pigments, anthraquinone pigments, perylene pigments, indigo/thioindigo pigments, dioxazine pigments, quinacridone pigments, indoline pigments, aniline pigments, and carbon black pigments.

Examples of inorganic pigments include titanium oxide based pigments, iron oxide based pigments, fired pigment based pigments, navy blue pigments, metal powder pigments, extender pigments, and the like.

When used as an electrophotographic developer,
Conventionally known charge control agents, cleaning agents, developer fluidity improvers, and the like can be added.

(Action/Effect) The coloring composition for image recording of the present invention has a pigment formation property I□
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Therefore, when the composition is finally used as a coloring composition for image recording, variations in chargeability between particles can be reduced. Even when used as a liquid developer, the interfacial potential is constant and the phenomenon can be stable for a long time.

Next, the present invention will be specifically explained with reference to Examples. still,
In the text, parts or percentages are by weight unless otherwise specified.

Example 1 30 parts of the dye represented by the above structural formula was mixed with a styrene-methacrylic copolymer (softening point: 110°C, glass transition point: 5°C).
The mixture was thoroughly kneaded at 6° C. with a three-roll machine with a GPC-based total weight average molecular weight of about 90,000 parts to disperse the dye. After cooling, the mixture was crushed to obtain a coarse powder of the highly concentrated coloring composition of the present invention containing a pigment at a concentration of 30%.

Next, 20 parts of the highly concentrated coloring composition containing the dye obtained above was mixed with 80 parts of the styrene-methacrylic copolymer used above.
After cooling, the mixture was kneaded according to a conventional method, pulverized after cooling, further pulverized with a jet mill, and classified to obtain a fine powder of the colored composition of the present invention having a size of 5 to 30 microns. The amount of triboelectrification of this colored composition was measured and found to be -8.2 ÷ microcoulombs/gram.

Colloidal silica is added as a fluidizing agent to the above red resin fine powder, mixed thoroughly according to a conventional method to form an electrophotographic dry developer, mixed with the magnetic iron of the carrier, and used in an electrophotographic copying machine for negative charge developers. Upon copying, a clear and stable copy image was obtained.

Example 2 20.8 parts of a highly concentrated coloring composition containing the dye represented by the structural formula of Example 1 at a concentration of 30 parts was mixed with Isopar G100 along with 15 parts of an acrylic ester resin soluble in an aliphatic hydrocarbon solvent. In addition, glass peas were further added to the mixture, and the mixture was shaken in a paint shaker for 20 hours to disperse the mixture to prepare a concentrated colored liquid of the present invention. Five parts of this concentrated colored liquid was added to 1 liter of Isopar G and dispersed to obtain an electrophotographic wet developer of the present invention. When this was copied using a wet-type electrophotographic copying machine, a clear copy image with a subdued color tone was stably obtained.

Patent applicant: Dainichiseika Industrial Co., Ltd.

Agent Patent Attorney Akira Koyama 1, Ni□＼゛go+
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Claims (4)

[Claims] (1) A coloring composition for image recording comprising a dye and a resin dispersion medium, characterized in that the dye is a dye represented by the following structural formula. ▲Contains mathematical formulas, chemical formulas, tables, etc.▼ (2) The coloring composition for image recording according to claim (1), which is a solid, paste or liquid composition containing a dye at a high concentration. (3) Claim No. 1 which is a solid fine powder developer
) The coloring composition for image recording according to item 1. (4) The coloring composition for image recording according to claim (1), which is a liquid developer.