JPS59197051A - Developer - Google Patents

Abstract

PURPOSE:To obtain a developer stabilizing the extent of triboelectric charge between toner and carrier, making the distribution of the extent of triboelectric charge sharp and uniform, and capable of controlling the extent of electrostatic charge to that suitable for a developing system used by adding benzothiazine (deriv.). CONSTITUTION:Benzothiazine represented by formula I , II, III, IV or V or a benzothiazine deriv. represented by formula VI, VII or VIII (where each of R1-R4 is H, halogen, alkyl, phenyl, OH, NH2, NO2 or the like) is added. The resulting developer stabilizes the extent of triboelectric charge among toner particles or between toner and carrier, makes the distribution of the extent of triboelectric charge sharp and uniform, and can control the extent of electrostatic charge to that suitable for a developing system used. When development is carried out with the developer, a fogging phenomenon and the scattering of the toner at the peripheral part of a latent image are not caused, high image density is attained, and the halftone part is well reproduced.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer used in electrophotography, electrostatic printing, etc., and particularly to a positively charging developer.

Conventionally, as an electrophotographic method, U.S. Patent No. 2,297,69
A number of methods are known, such as in the specification of No. 1.

Further, a developing method for visualizing an electrical latent image using a developer (generally toner) is described, for example, in U.S. Pat. No. 2,874,0
No. 63, No. 2,618,552, No. 2,221,77
Various methods are known, as described in the specifications of No. 6 and No. 3,909,258.

As toners applied to these developing methods, fine powders in which dyes and pigments are dispersed in natural or synthetic resins have conventionally been used. For example, particles obtained by dispersing a colorant in a binder resin such as polystyrene and pulverizing the particles to about 1 to 30 μm are used as toner. As the magnetic toner, one containing magnetic particles such as magnetite is used. In the case of a system using a so-called two-component developer, the toner is usually mixed with carrier particles such as glass beads and iron powder.

Examples of positive charge control agents used in such dry developing toners include amino compounds.

Quaternary ammonium compounds and organic dyes, especially basic dyes and their salts. Common positive charge control agents include hensyl dimethyl-hexadecyl ammonium chlorite, tesyl trimethyl ammonium chloride, nigrosine base, nigrosine hydrochloride, safranin γ, and crystal violet. In particular, nigrosine base and nigrosine hydrochloride are often used as positive charge control agents. These are usually added to a thermoplastic resin, heated and melted and dispersed, and then finely ground to adjust the particle size to an appropriate particle size as necessary before use.

However, these dyes used as charge control agents have complex structures, inconsistent properties, and poor stability. In addition, decomposition or deterioration occurs due to decomposition during thermal kneading, mechanical impact, friction, changes in temperature and humidity conditions, etc., resulting in a phenomenon in which charge controllability deteriorates.

Therefore, when a toner containing these dyes as a charge control agent is used for development in a copying machine, as the number of copies increases,
The dye decomposes or changes in quality, causing toner deterioration during durability. Furthermore, many of the substances generally known as positively chargeable have a dark color and cannot be incorporated into a bright chromatic developer.

In addition, many of the positive charge controllable dyes are hydrophilic, and due to poor dispersion in these resins, the dyes are exposed on the toner surface when they are crushed after melt-kneading. When the toner is used under high humidity conditions, it has the disadvantage that it is difficult to obtain a good quality image because these dyes are hydrophilic. When using a dye having a toner in a toner, variations occur in the amount of charge generated on the toner particle surface between toner particles, between a toner and a carrier, or between a toner and a toner carrier such as a sleeve. , development capri, toner scattering, carrier contamination, and other problems occur. However, these phenomena become particularly noticeable when a large number of copies are made, and the result is practically unsuitable for copying machines.

Furthermore, under high humidity conditions, the toner image transfer efficiency is significantly reduced, making it unusable. Furthermore, even at room temperature and humidity, when the toner is stored for a long period of time, the toner often aggregates and becomes unusable due to the instability of the positive charge control dye used.

That is, an object of the present invention is to stabilize the amount of triboelectric charge between toner particles or between a toner and a carrier, or between a toner and a toner carrier such as a sleeve in the case of component development, and to maintain a stable triboelectricity distribution. To provide a developer that is sharp and uniform, and whose charge amount can be controlled to suit the developing system used.

Still another objective is to develop the latent image faithfully and to use the developer for transfer, that is, to avoid adhesion of toner in the background area during development, that is, to avoid fogging and toner scattering around the edges of the latent image. The object of the present invention is to provide a developer that provides high image density and good reproducibility of the -7 tone.

Still another object is to provide a developer that maintains its initial characteristics even when the developer is used continuously over a long period of time, and that causes no toner aggregation or change in charging characteristics.

Another objective is to develop a developer that reproduces stable images unaffected by changes in temperature and humidity, especially a developer with high transfer efficiency that does not cause splatters or transfer omissions during transfer at high or low humidity. The purpose is to provide drugs.

Still another object is to provide a developer with excellent storage stability that maintains its initial characteristics even during long-term storage.

Still another object is to provide a bright chromatic developer.

The present inventors have solved the various problems associated with conventional positively charged toners as described above, and have developed an electrophotographic method that is uniformly and strongly positively charged, visualizes negative electrostatic charge images, and produces high-quality images. As a result of intensive research aimed at providing a developer for use in electrophotography, it was discovered that if the developer contains benzothiazine or a benzothiazine derivative as a positive charge control agent, a developer for electrophotography exhibiting various excellent properties can be obtained. I found it.

Binder resin is added to the developer toner as necessary.

Colorants, additives, etc. are used.

Of course, benzothiazine itself is effective as the positive charge control agent mentioned above, but when handling and charge stability are taken into account,
Derivatives thereof are preferred.

Benzothiazine is the following (1), (n)'t, (I
II) , (IV) , (V) It is known that
All of them have the same practical effect.

1,2-benzothiazine 2,1-benzothiazine (1) (II)
(V') These derivatives include, for example, those having a skeleton of 1,2-benzothiazine, those having the general formula (here, R,, R
2, R is hydrogen, halogen, akoki'y group, x stellate group, alkoxycarbonyl group, phenyl group, R-substituted phenyl group, hydroxy group, mercapto group, alkylmercapto group, ami7 method, acyl group, acylamino group, Nitro group.

imino group, phenylimino group, cyano group, m-substituted azo group,
Represents a substituent of a diazoamino group, a ureido group, an oxo group, or a heterocyclic ring containing nitrogen, sulfur, or oxygen. ) Examples of derivatives having a skeleton of 01,3-benzothiazine include those represented by the general formula (where Rs, Rt-Rs, and R4 have the same meanings as above).

Further, as a derivative having 1,4-benzothiazine as a skeleton, lotus2 (herein, R,, R2, and R have the same meanings as above).
There is something expressed as

2.1-benzothiazine and 3,1-benzothiazine can be similarly defined.

The charge control effect of these substituents on benzothiazine derivatives basically depends on the thiazine skeleton, and the color can be changed by selecting various substituents.

Since they have different melting points, they can be selected according to need.

The method of incorporating at least one kind of benzothiazine or benzothiazine derivatives into a developer is as follows:
There are two methods: adding to the inside of the toner particles (internal addition) and adding to the outside (external addition). When internally added, the content is 0.5 to 50 parts by weight per 100 parts by weight of the binder resin of the toner.
Parts by weight are preferred. When externally added, it is preferably 0.01 to 40 parts by weight per 100 parts by weight of the resin.

As the binder resin of the toner, polystyrene, PVP-P
Monopolymers of styrene and its substituted products such as lorstyrene and polyvinyltoluene; styrene-P-chlorostyrene copolymers, styrene-propylene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, Styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate Copolymer, styrene-butyl methacrylate copolymer, styrene-alpha chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinylethyl ether copolymer, styrene -vinyl methyl ketone copolymer, styrene-butadiene copolymer,
Styrenic copolymers such as styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polychloride Vinyl, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic Petroleum resins, chlorinated paraffin, paraffin wax, etc. can be used alone or in combination.

Any suitable pigment or dye can be used as a colorant in the toner of the present invention. For example, carbon black,
There are known dyes and pigments such as iron black, phthalocyanine blue, ultramarine blue, quinacridone, and benzidine yellow.

When the toner is a magnetic toner, magnetic materials conventionally known as magnetic materials such as ferromagnetic elements, alloys containing these, iron compounds such as magnetite, hematite, and ferrite, compounds, and other ferromagnetic alloys are used. It may also contain powder.

Additives may be mixed with the toner as necessary. Such additives include, for example, lubricants such as Teflon and zinc stearate, fixing aids (such as low molecular weight polyethylene), flow agents, anti-caking agents (such as colloidal silica), or conductivity agents. Examples include metal oxides such as tin oxide.

It is also possible to have the above toner structure supported on the wall material, the core material, or both of them in the microcapsule toner.

For toner, use iron powder or glass peas as needed.

It may be mixed with carrier particles such as nickel powder or ferrite powder and used as a developer for electrical latent images.

When producing toner, the constituent materials are thoroughly kneaded using a thermal kneading machine such as a hot roll, kneader, or extruder, and then obtained by mechanical crushing or classification, or after the materials are dispersed in a binder resin solution. , a method of obtaining toner by spray drying, or a polymerization method of obtaining a toner by mixing a predetermined material with a monomer to constitute a binder resin and then polymerizing this emulsified suspension. Applicable Methods The developer of the present invention can be applied to various development methods. For example, a magnetic brush development method, a cascade development method, a method using conductive magnetic toner described in U.S. Pat. There are methods using toner, methods described in JP-A No. 54-42141, JP-A No. 55-18656, JP-A No. 54-43027, etc., fur brush development method, Balagu cloud method, impression development method, etc. It is possible to use force, image force, mechanical force, etc.

Examples will be described below, but the present invention is not limited thereto. In addition, all parts are parts by weight.

[Example 1] 100 parts of toner having an average particle size of 8 μm was mixed with 1000 parts of iron powder carrier to prepare a developer.

When this developer was used in a Canon NP-8500 copying machine, a good image with no fog was obtained with a bright blue color, and this image did not change even after printing 100,000 copies. Ta.

In addition, under a high humidity environment of 35°C and 90% RH, and at 15°C,
Even at a low humidity of 10% RH, images with almost no difference from normal humidity were obtained.

[Example 2] When images were printed using a modified Canon NP-200 copier, good images with no fog were obtained, and even after printing 10,000 images, the images remained in good condition. .

In addition, under high humidity conditions of 35°C and 90% RH, and at 15°C and 10%
Even at low humidity of %RH, images with almost no difference from normal humidity were obtained. [Example 3] An experiment was carried out in the same manner as in Example 1, except that 1-methyl-3-ethoxycarbonyl-4-hydroxy-IH-2,1-benzothiazine 2,2 dioxide was used. The results were obtained.

[Example 4] 2-ethylamino-4-phenyl-6-rio[nyl-4
Good results were obtained using 2 parts of H-3,1-benzothiazine.

Example 5] An experiment was conducted in the same manner as in Example 1, except that 5 parts of 2-ethylamino-4-methyl-4H-3,1-benzothiazine was used, and good results were obtained.

Example 6] An experiment was carried out in the same manner as in Example 1, except that 2-amino-4-phenyl-4H-3,1-benzothiazine was used, and good results were obtained.

Comparative Example 1] Example 1 except that 3-benzoyl-2-(2-biperidinoethyl)-3,4-dihydro-2H-1,2-benzothiazin-4-one and 1,1-dioxide were not used. When an experiment was conducted in the same manner as in 1, only images with low density and a lot of scattering were obtained.

Comparative Example 2] In Example 2, an experiment was conducted in the same manner as in Example 2, except that the benzothiazine used in Example 1 was not used.
Images with a lot of fog were obtained, and when 500 images were obtained in succession, only very faint images were obtained0 Applicant: Canon Corporation 365

Claims (1)

[Claims] Benzothiazine is a developer containing benzothiazine derivatives.