JPH01204073A - Developer composition - Google Patents

Abstract

PURPOSE:To obtain a developer compsn. contg. a toner which is electrostatically charged positive when used for development of an electrostatic latent image by using ferrite particles coated with a coating agent contg. a vinylidene fluoride copolymer as the carrier of the developer compsn. consisting of the dry process toner and using a toner contg. a charge control agent of a quaternary ammonium salt type as the toner. CONSTITUTION:The developer compsn. is constituted of the magnetic carrier and the toner and the ferrite particles coated with the coating agent contg. the vinylidene fluoride copolymer is used as the carrier. The toner is prepd. by incorporating the charge control agent of the quaternary ammonium salt which consists of the compd. expressed by the formula and is incorporated in the binder resin at 0.1-10pts.wt. per 100pts.wt. resin into said binder. In the formula, R1, R2 respectively denote a hydrogen atom, substd. or unsubst. alkyl group, substd. or unsubstd. aryl group, substd. or unsubstd. cycloalkyl group; X<-> denotes anion.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a magnetic brush developing carrier used for developing electrostatic latent images in electrophotography and electrostatic recording.
The present invention relates to a developer composition comprising a dry toner whose chargeability is controlled with a class ammonium salt.

Conventional technology In electrophotography, a photoconductive substance such as selenium is used as a photoreceptor, an electrical latent image is formed using various means, and this latent image is developed using a magnetic brush development method or the like. Generally, a method is adopted in which toner is attached and visualized.

In this development process, carrier particles called carrier particles are used to impart an appropriate amount of positive or negative electrical loss to the toner. Carriers are generally classified into coated carriers and uncoated carriers, but the former is superior when considering developer life, so various types of coated carriers have been developed and It has been put into practical use.

Problems to be Solved by the Invention] - There are various characteristics required of carriers, but
Particularly important properties include appropriate charging properties, impact resistance, good adhesion between the core and coating material, and uniformity of charge distribution.

Considering the above-mentioned required characteristics, the coated carriers used conventionally still have problems to be improved, and no perfect one is known so far. For example, when vinyl fluoride polymers are used, they have excellent surface stain resistance, but there are problems with adhesion to the core, and when acrylic polymers are used, mechanical strength and core Although it was satisfactory in terms of adhesion with other materials, problems occurred in surface stain resistance and charging properties. In any case, the current situation is that we are forced to use coating materials that have some problems.

The present invention has been made in view of the current situation.

Therefore, it is an object of the present invention to provide a novel developer composition containing a positively charged toner, which is used for developing electrostatic latent images in electrophotography and electrostatic recording. .

Another object of the present invention is that since the charging rate is high and the surface contamination resistance is good, the amount of charging does not decrease during running, and as a result, fogging occurs early and contamination inside the machine does not occur. Another object of the present invention is to provide a developer composition that exhibits stable development characteristics even against environmental changes such as temperature and humidity.

Means for Solving the Problems The inventors of the present invention have repeatedly conducted various studies and examinations in order to improve the above-mentioned conventional drawbacks, and as a result, the present inventors used a specific resin as a coating material for the carrier, and used a 4-treated ammonium salt as a toner. The inventors have discovered that the above-mentioned required characteristics can be improved by using a material controlled by the above conditions, and have completed the present invention.

The above object of the present invention is achieved by using, as a carrier, ferrite particles coated with a coating agent containing a vinylidene fluoride copolymer, and as a toner, using one containing a quaternary ammonium salt type charge control agent. can be achieved. That is, the developer composition of the present invention is a two-component developer comprising a magnetic carrier and a toner, the magnetic carrier comprising ferrite particles coated with a coating material containing a vinylidene fluoride copolymer, Further, the toner is characterized in that the binder resin contains a quaternary ammonium salt type charge control agent.

The present invention will be explained in detail below.

In the present invention, ferrite particles are used as the carrier. Various ferrites can be used as the ferrite. Moreover, the average particle size is 10 to 500 II
Jri range is preferably used.

On the other hand, the coating agent for coating the ferrite particles contains a vinylidene fluoride copolymer. The vinylidene fluoride copolymer used in the present invention is composed of vinylidene fluoride and other copolymerizable monomers. Examples of copolymerizable monomers include fluorine-containing vinyl monomers such as tetrafluoroethylene, trifluoroethylene, hexafluoropropylene, and chlorotrifluoroethylene, and chlorine-containing vinyl monomers such as vinyl chloride and vinylidene chloride. Examples include olefinic monomers such as , ethylene, and propylene. These monomers can be used alone or in combination of two or more types, which can be copolymerized with vinylidene fluoride. In the vinylidene fluoride copolymer of the present invention, the copolymerizable monomer can be copolymerized in a range of 70 to 5 mol%. If the polymerization ratio of copolymerizable monomers is higher than 70 mol%, the charging property of the vinylidene fluoride copolymer will deteriorate, and if it is lower than 5 mol%, the vinylidene fluoride copolymer will deteriorate. Solubility in solvents deteriorates.

Typical vinylidene fluoride copolymers used in the present invention include vinylidene fluoride-hexafluoropropylene copolymer, vinylidene fluoride-trifluoroethylene copolymer, and vinylidene fluoride-tetrafluoroethylene copolymer. These vinylidene fluoride copolymers, exemplified by ethylene-hexafluoropropylene terpolymers, can be used alone or in combination with the above resin, and can be used with acrylic resins. It is preferable to use it as a mixture of. When using the same resin, the amount thereof is set to 50% by weight or less. Examples of the acrylic resins used include methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, and dodecyl methacrylate. Examples include homopolymers and copolymers such as .

In the present invention, magnetic chitria particles are produced by surface-treating ferrite particles as described above with a coating agent containing a vinylidene fluoride copolymer to form a coating layer on the surface of the ferrite particles by chemical bonding or adsorption. Obtainable. The coating amount of the resin containing the vinylidene fluoride copolymer is preferably set in the range of 0.05 to 3.0% by weight based on the ferrite particles.

For surface treatment of ferrite particles, for example, the above-mentioned vinylidene fluoride copolymer is dissolved in an appropriate solvent together with other resins if necessary, the ferrite particles are immersed in the resulting solution, and then A method of desolvation, drying, high temperature baking, or suspending ferrite particles in a fluidized bed,
A method of spraying the above solution, drying it, and baking it at a high temperature can be used. Incidentally, in these methods, high temperature baking treatment is not necessarily required.

On the other hand, as the toner, one containing a quaternary ammonium salt type charge control agent is used. Any known quaternary ammonium salt type charge control agent can be used.

Furthermore, a charge control agent represented by the following general formula (I>) can also be used. (In the formula, R1, R2, and R3 are the same or different groups, and are hydrogen atoms, substituted or (represents an unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or unsubstituted aralkyl group, or a substituted or unsubstituted cycloalkyl group; A method of neutralizing unsubstituted amino-ε-caprolactam with the corresponding acid, or α-
It can be synthesized by quaternizing disubstituted amino-ε-caprolactam with an alkyl halide or aralkyl halide, etc., and exchanging the counter ion with a corresponding acid as necessary.

Specific examples of the charge control agent represented by the above general formula (1) and other quaternary ammonium salt type charge control agents that can be used in the present invention include the following.

In the present invention, the charge control agent represented by the above general formula is
0.1 to 10 parts by weight per 100 parts by weight of the toner binder resin.
It is preferable to add it in a proportion of 0 parts by weight.

Binder resins used in toners include styrenes such as styrene and chlorostyrene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate, and butyrotinyl; methyl acrylate, ethyl acrylate, and butyl acrylate. , α-methylene aliphatic monocarboxylic acid esters such as dodecyl acrylate, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate; vinyl methyl ether, vinyl ethyl ether, vinyl Vinyl ether such as butyl ether; vinyl methyl ketone,
Vinyl ketones such as vinyl hexyl ketone and vinyl isopropenyl ketone; homopolymers and copolymers of olefins; particularly representative binder resins include polystyrene and styrene-alkyl acrylate copolymers. , styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, styrene-maleic anhydride copolymer, polyethylene, polypropylene, and the like.

Further examples include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin, and paraffin wax.

In addition, toner coloring agents include carbon black, aniline blue, calcoyl blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, and phthalocyanine blue.
, malachite green oxalate, lamp black,
Representative examples include Rose Bengal and the like.

In the present invention, the average particle size of the toner is set to about 30 pm or less, preferably in the range of 3 to 20 pm.

In the present invention, the toner may be a magnetic toner containing a magnetic material or a capsule toner.

The developer composition of the present invention is composed of the above-mentioned magnetic carrier and toner, but various additives can be added as necessary. These additives include various additives such as charge control agents, cleaning aids, fluidity promoters, and the like.

The developer composition of the present invention is used to develop an electrostatic latent image formed on a photoreceptor or an electrostatic recording medium. That is, an electrostatic latent image is electrophotographically formed on a photoreceptor made of an inorganic photoconductive material such as selenium, zinc oxide, cadmium sulfide, or amorphous silicon, or an organic photoconductive material such as a phthalocyanine pigment or bisazo pigment, or an electrostatic latent image is formed on a photoreceptor made of an organic photoconductive material such as a phthalocyanine pigment or a bisazo pigment. An electrostatic latent image is formed on an electrostatic recording medium having a dielectric material such as terephthalate using a needle-shaped electrode, and the electrostatic latent image is formed using a developing method such as a magnetic brush method, a cascade method, or a touchdown method. A developer composition is applied to form a toner image. This toner image is transferred to a transfer material such as paper and fixed to form a copy, and the toner remaining on the surface of the photoreceptor is cleaned.

Example Hereinafter, the present invention will be explained in more detail with reference to Examples.

However, the present invention is not limited in any way by these Examples.

Example 1 Styrene-butyl acrylate 100 parts copolymer (copolymerization ratio 80/20) Carbon black 10 parts (Zigal 330: manufactured by Capotsu 8) Low molecular weight polypropylene 5 parts (Viscol 660p: manufactured by Sanyo Kasei ■) Examples Compound <1) 1 part The above ingredients are melted and kneaded in a Banbury mixer,
After cooling, the mixture was finely pulverized using a jet mill, and the pulverized product was further classified using a separator to obtain a toner having an average particle size of 11 mm.

On the other hand, 16 parts of vinylidene fluoride-trifluoroethylene copolymer (copolymerization ratio 75/25) and 4 parts of polymethyl methacrylate were dissolved in 100 parts of dimethylformamide. The obtained solution was added to 2000 parts of spherical ferrite having an average particle size of 100 mm, and a coating treatment was performed using a reduced pressure kneader coater.1. I got a career.

A developer composition was obtained by mixing 3 parts of the above toner and 100 parts of the above carrier.

Example 2 100 parts of styrene-butyl acrylate copolymer (copolymerization ratio 80/20) 10 parts of carbon black (Sogal 330: manufactured by Kabotsu 8) 5 parts of low molecular weight polypropylene (Viscol 660p)
: Manufactured by Sanyo Kasei VTJ) Exemplary Compound (7) 1 part A toner was obtained by the same treatment as in Example 1 except for using the above components, and mixed in the same manner as in Example 1 with the same carrier. A developer composition was obtained.

Example 3 Styrene-butyl acrylate 100 parts copolymer (copolymerization ratio 80/20) Carbon black 10 parts (Sogal 330: manufactured by Kabotsu 8) Low molecular weight polypropylene 5 parts (Viscol 660p: manufactured by Sanyo Kasei ■) Exemplary compound 8 ) A toner was obtained in the same manner as in Example 1 except that 1 part of the above components were used.

On the other hand, a carrier was prepared in the same manner as in Example 1, except that 16 parts of vinylidene fluoride-hexafluoropropylene copolymer (copolymerization ratio 80/20) and 4 parts of polymethyl methacrylate were dissolved in 100 parts of dimethylformamide. Obtained.

These toners and carriers were mixed in the same manner as in Example 1 to obtain a developer composition.

Example 4 Styrene-butyl acrylate 100 parts Copolymer (copolymerization ratio 80/20) Carbon black 10 parts (Sogal 330: manufactured by Kabotsu 8 Co., Ltd.) Low molecular weight polypropylene 5 parts (Viscol 660p: manufactured by Sanyo Chemical Co., Ltd.) Exemplary compound ( 19)
Except for using one part of the above ingredients,
A toner was obtained by processing in the same manner as in Example 1. On the other hand, the carrier obtained in the same manner as in Example 3 was used. These were mixed in the same manner as in Example 1 to obtain a developer composition.

Example 5 Styrene-butyl acrylate 100 parts copolymer (copolymerization ratio 80/20) Carbon black 10 parts (Sogal 330: manufactured by Kabotsu 8 Co., Ltd.) Low molecular weight polypropylene 5 parts (Viscol 660p: manufactured by Sanyo Kasei <ti) Exemplary compounds (21)
The toner was processed as in Example 1 except that one part of the above components was used.
is. On the other hand, the carrier obtained in the same manner as in Example 3 was used. These were mixed in the same manner as in Example 1 to obtain a developer composition.

Comparative Example 1 A developer composition of 1 q was prepared in the same manner as in Example 1 except that no charge control agent was used.

Comparative Example 2 Styrene-butyl acrylate 100 parts copolymer (copolymerization ratio 80/20) Carbon black 10 parts (Sogal 330: manufactured by Kabotsu 8) Low molecular weight polypropylene 5 parts (Viscol 660p: manufactured by Sanyo Kasei ■) Nigrosine dye ( Bontron N-03: 1 part manufactured by Orient Kagaku N) A developer composition was obtained by processing in the same manner as in Example 1 except for using the above components.

Comparative Example 3 A solution obtained by dissolving 20 parts of polymethyl methacrylate in 100 parts of toluene was added to 2000 parts of spherical ferrite having an average particle size of 100111 nm, and the mixture was treated with a vacuum kneader coater to obtain a ferrite carrier.
A developer composition was obtained in the same manner as in Example 1.

Using these developer compositions of Examples 1 to 5 and Comparative Examples 1 to 3, a continuous copying test was conducted using an electrophotographic copying machine (Xerox 1065, manufactured by Xerox Corporation). The results obtained are shown in Table 1.

Table 1 Effects of the Invention Since the developer composition of the present invention has the above-mentioned structure, as is clear from the above comparison, it has good charging properties, a high charging rate, and good surface stain resistance. Therefore, the amount of charge does not decrease during running. As a result, when the developer composition of the present invention is used, there is no occurrence of early fogging or contamination in the copying machine, and there is no need to worry about temperature
It exhibits stable development characteristics even against environmental changes such as humidity,
An excellent effect is produced in that copy images of excellent image quality can be obtained over a long period of time.゛Patent applicant Fuji Xerox Co., Ltd. Agent Patent attorney Tsuyoshi Horabe

Claims (2)

[Claims] (1) A developer composition comprising a magnetic carrier and a toner, wherein the magnetic carrier comprises ferrite particles coated with a coating material containing a vinylidene fluoride copolymer, and the toner is contained in a binder resin. A developer composition comprising: a quaternary ammonium salt type charge control agent; (2) The quaternary ammonium salt type charge control agent is composed of a compound represented by the following general formula, and is contained in a proportion of 0.1 to 10.0 parts by weight per 100 parts by weight of the binder resin. The developer composition according to claim (1). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (In the formula, R_1, R_2, and R_3 are each the same or different groups, and include a hydrogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted aryl group, a substituted or an unsubstituted aralkyl group, or a substituted or unsubstituted cycloalkyl group, and X^- represents an anion)