JPS59197050A - 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 a specified xanthogen compound. CONSTITUTION:A xanthogen compound represented by formula I , II or III(where each of R1-R5 is H, alkyl, phenyl, OH, NO2 or the like. each of X and Y is Na, K, Cu or the like, and X may be H) 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 that can be charged, and particularly to a positively chargeable developer.

Conventionally, many electrophotographic methods are known, such as those disclosed in US Pat. No. 2,297,691.

A developing method for visualizing an electrical latent image using a developer (generally toner) is described, for example, in U.S. Pat. No. 2,874,08.
No. 3, No. 2,818,552, No. 2,221,776
Various methods are known, as described in the specifications of No. J909, No. 258 and the like.

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 liters 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.

Positive charge control agents used in such dry development toners are, for example, generally amino/compounds, quaternary ammonium compounds, and organic dyes, particularly basic dyes and their salts. Common positive charge control agents include hensyldimethyl-hexadecyl ammonium chloride, decyl-trimethylammonium chloride, nigrosine base, nigrosine hydrochloride, safranin gamma, and crystal 7 iolent. In particular, nicrosine base and nigrosine hydrochloride are often used as positively charged flMI 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 required.

However, these charge control agents lack magnetism. In addition, decomposition or deterioration occurs due to decomposition during heat kneading, mechanical impact, friction, changes in temperature and humidity conditions, etc., resulting in a phenomenon in which charge controllability is reduced.

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 is dispersed or altered, causing deterioration of the I-ner during fireproofing. Moreover, many of the substances generally known to be positively chargeable have a dark color, and therefore have the disadvantage that they can only be contained in a bright right-colored developer.

In addition, many of the positive charge control dyes are hydrophilic, and the amount of these dyes in the resin is 119. Due to defects, after melting and kneading,
When crushed, dye keys are exposed on the surface of the toner.When using the toner under high temperature conditions, there is a drawback that these dyes are woody, making it difficult to obtain high-quality images. It has a sharp edge.

In this way, when conventional dyes with positive charge controllability are used in toner, dyes are generated on the toner particle surface between toner particles, between toner and carrier, or between toner and toner carrier such as a sleeve. This causes variations in the amount of charge, causing problems such as development fog, toner scattering, and carrier contamination. Moreover, 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 temperature conditions, the toner image transfer efficiency is significantly reduced, making it unsuitable for use. Further, even at room temperature, when the toner is stored for a long period of time, due to the instability of the positive charge control dye used, the toner often aggregates and becomes unusable.

That is, an object of the present invention is to stabilize the amount of triboelectric charge between toner particles, 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 object is to develop a developer that faithfully develops and transfers the latent image, i.e.
To provide a developer which is free from toner adhesion in areas, that is, fog, and toner scattering around the edges of latent images, provides high image density, and has good halftone reproducibility.

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 that has high transfer efficiency and does not cause scattering or transfer dropouts during transfer at high or low humidity. It's on offer.

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 electronic toner that is uniformly and strongly positively charged, visualizes negative electrostatic charge images, and produces high-quality images. As a result of intensive research with the aim of providing a photographic developer, we have found that a positive charge control agent with the general formula group, hydroxy group, phenyl group, substituted phenyl group, mercapto group, amine group, acylamino group, nitro group, chisel 7 groups.

Represents a phecolimino group, a cyano group, a ureido group, or a multi-ring substituent containing nitrogen; sulfur or oxygen, and X and Y are metal elements such as sodium, potassium, copper, zinc, iron, and lead. and X may be hydrogen. It has been found that if a developer contains at least one of the xanthogen compounds represented by the following formulas, an electrophotographic developer exhibiting various excellent properties can be obtained.

Most of the xanthogen compounds mentioned above are colorless or light-colored, and are very suitable for producing bright chromatic toners. The charge control effect of the above xanthogen compound basically depends on the xanthogen skeleton, and the melting point varies depending on various selections of substituents, which may be selected as necessary.

The developer toner contains binder resin, colorant, and
Use additives, etc.

Methods for incorporating at least one of these xanthogen compounds into the developer include a method of adding it to the inside of the toner particles (internal addition) and a method of adding it to the outside (external addition). When internally added, the content is 1 part of the binder resin of the toner.
0.00 parts by weight, 13 parts by weight, preferably 0.5 to 50 parts by weight. In addition, when adding externally, 0,
01 to 40 parts by weight is desirable.

As the binder resin of the toner, monopolymers of styrene and its substituted products such as polystyrene, poly-P-chlorostyrene, and polyvinyltoluene; styrene-P-chlorostyrene copolymers, styrene-prohyrsine co-ffi polymers,
Styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-acrylate copolymer.

butyl methacrylate copolymer, styrene-acrylic octyl copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α-chloromethacrylate copolymer Methyl copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinylethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer Polymer, styrenic copolymer such as styrene-acrylonitrile-indene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer: polymethyl methacrylate-1,
Polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyacrylic resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic resin Hydrocarbon resin, aromatic petroleum resin, 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, fucrocyanine blue, gun blue, quinacridone, and benzidine yellow.

When the toner is a magnetic toner, conventional materials such as ferromagnetic elements, alloys containing these, compounds such as magnetite, hematite, ferrite, alloys and compounds of iron, cohardt, ninkel, manganese, and other ferromagnetic alloys are used. Magnetic powder, which is known as a more magnetic material, may also be included.

Additives may be mixed with the toner as necessary. Such additives include, for example, lubricants such as Teflon, butyzinc stearate, fixing aids (such as low molecular weight polyethylene), flow agents, anti-caking agents (such as colloidal silica), or conductive agents. Examples of the imparting agent include metal oxides such as soot 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 L・Na, use iron powder and crow beads 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.

Toner is produced by thoroughly kneading the constituent materials using a thermal kneader such as a hot roll, kneader, or extruder, followed by mechanical crushing or classification, or by dispersing the materials in a binder resin solution. There are many methods for producing toner, such as methods for obtaining toner by spray drying, or polymerization methods for obtaining toner by mixing predetermined materials with the monomers that constitute the binder resin and then polymerizing this emulsified suspension. The method can be applied.

The developer of the present invention can be applied to various development methods. For example, the magnetic brush development method, the cascade development method, the derivative 1' described in U.S. Pat. No. 3,909,258,
Method using E magnetic toner, JP-A II? (53-31
Method using high-resistance magnetic toner described in JP-A-138, JP-A-54-42141, JP-A-55-1865
Examples include methods described in Japanese Patent No. 8 and No. 54-43027, a fur brush development method, a powder cloud method, an impression development method, and the like.

Further, when the developer is held in a developer carrier such as a sleeve, it is possible to use magnetic force, Coulomb force, electrostatic force, image force, mechanical force, etc.

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

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

When this developer was used to print an image on a Canon Acid NP-8500 copying machine, a good image with a bright blue color and no fog was obtained, and the image did not change even after printing 100,000 copies. There wasn't.

Further, even under a high temperature environment of 35° (1!, 90% RH) and a low humidity of 15° C. and 10% RH, images with almost no difference from normal humidity were obtained.

Furthermore, when an image was obtained using a developer that had been left in a high humidity environment of 35° C. and 990% RH for one month, good results were obtained that were the same as those before being left.

[Example 2] When images were produced using a Cannon acid NP-200 copying machine modified to form a negative charge latent image using the toner made of Even after removal, the condition continued to be -1 good.

In addition, under high humidity conditions of 35°C and 90% RH, and at 15°C1
Even under low humidity conditions of 10% RH, images with no difference between normal humidity and 4i images were obtained.

[Example 3] An experiment was conducted in the same manner as in Example 1, except that inpropylxanthochene 1% d-1-1,1um was used instead of zinc isopropylxanthate in Example 1. The same good results were obtained.

[Example 4] An experiment was conducted in the same manner as in Example 1, except that lead aminopropylxanthate was used instead of zinc isopropylxanthate in Example 1, and good results were obtained.

[Comparative Example 1] An experiment was carried out in the same manner as in Example 1, except that the zinc inpropyl xanthate in Example 1 was not used, and only images with low density and a lot of scattering and fogging were obtained.

[Comparative Example 2] An experiment was carried out in the same manner as in Example 2 except that the zinc inpropyl xanthate in Example 2 was not used. Images with a lot of fog were obtained. When 500 images were continuously obtained, I could only get a very faint image.

Applicant: Canon Co., Ltd.

Claims (1)

[Claims] = General formula % formula % ( ]] (wherein, R1-R5 are hydrogen, alkyl group, alkenyl group, alkynyl group, alkoxy group, alkoxycarbonyl group, hydroxy group, phenyl group, substituted phenyl group) , mercapto group, amine group, acylamino group, kotro group, nomino group.Represents any substituent of a phenylimino group, cyan group, ureido group, or a plurality of rings containing nitrogen, sulfur, or oxygen, and X, Y represents a metal element such as sodium, potassium, copper, zinc, iron, or lead, and X may be hydrogen.