JPH09160302A - Charge controlling agent for electrostatic charge image development, and toner and charge imparting member using that - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high-quality toner for electrostatic charge image development which is excellent in electrification stability and hardly causes contamination on a copy by using barium sulfate or a compd. having a specified structure as a charge controlling agent. SOLUTION: This charge controlling agent for electrostatic charge image development consists of barium sulfate or a compd. expressed by [A-(-SO3 )2 ]Ba, and this agent is used to obtain a toner and a charge imparting member. In formula, A is an aromatic ring residue which may have substituents. As for the aromatic ring residue, arylene groups such as phenylene and naphthylene groups can be used, and especially, naphthylene groups are preferable. The residues may have 1 or more substituents except for a sulfonyl group, the substituents are 1-6C alkyl groups, hydroxyl groups, etc., and especially hydroxyl groups are preferable. Or the residues may have two or more kinds of substituents or a plural number of the same substituents. Especially, barium sulfate is preferable because it is excellent in characteristics as required and safe for a human body.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge controlling agent for developing an electrostatic image used in an electronic copying machine and the like, and a charge applying device for applying a charge to a toner using the same and a toner used for developing an electrostatic image. It is about materials.

[0002]

2. Description of the Related Art In a developing process, a developer used in an electronic copying machine or the like is once adhered to an image carrier such as a photoreceptor on which an electrostatic image is formed, and then is exposed to light in a transfer process. After being transferred from the body to the transfer paper, it is fixed on the copy paper surface in a fixing step. At that time, as a developer for developing the electrostatic image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner and a one-component developer (magnetic toner) not requiring the carrier
It has been known.

By the way, one of the important characteristics required for toner is chargeability, and in particular, contact with the carrier or the vessel wall of the developing tank causes an appropriate positive or negative charge, and The charge level is required to be substantially stable over time even during continuous use or under adverse effects. The chargeability may be imparted to the toner by using the binder resin or the colorant itself, but it is difficult to obtain sufficient chargeability. Therefore, a positive charge control agent that imparts chargeability to the toner is conventionally used. Chargeable Nigrosine dye,
A method has been known in which a quaternary ammonium salt, a negatively chargeable metal-containing monoazo dye, a salicylic acid metal complex, a copper phthalocyanine pigment or the like is contained in a toner and used.

[0004]

However, although these conventional charge control agents have high charge levels, they often do not have sufficient charge stability. For example, during continuous copying and continuous printing, the charge level is increased. Has a problem that it may change over time, causing smearing of the copy.
These problems tend to increase in recent years particularly with the demand for a copying machine or the like that can process a large number of sheets continuously and at high speed, and development of a charge control agent having more excellent charge stability is required. There is.

On the other hand, in addition to the above-mentioned charge control agent, the improvement of the charge imparting property to the toner is carried out by the carrier, the developing sleeve, the layer forming blade, etc. which come into contact with the toner during the developing process. Member (hereinafter referred to as "charge-giving material" including these) is a material that can be brought into contact with toner prior to or during the development process to give the toner the charge necessary for the development, or a material that can supplement the charge. Or the members are collectively referred to). As the charge-imparting material, a material having a high durability against friction with the toner is required, and particularly, a material that can be used without changing the carrier for a long time is desirable.

[0006]

Therefore, the present inventors have provided a high-quality toner for developing an electrostatic image which is excellent in charging stability and is less likely to cause copy stains, and has a long-term performance. In order to provide a charge-imparting material that provides an image with excellent fine line reproducibility and gradation without deterioration, as a result of diligent study, by using a compound having a specific structure as a charge control agent, The inventors have found that the problems are solved and have reached the present invention.

That is, an object of the present invention is to provide a charge control agent which is excellent in charge stability and is also excellent in other required properties of toner such as humidity resistance, light resistance and heat resistance. It is an object of the present invention to provide a charge-imparting material and a high-quality toner in which the print density is moderate and stable even when adversely affected during use, and copy stains are less likely to occur. Another object of the present invention is to provide a charge control agent excellent in safety.

That is, the gist of the present invention is barium sulfate or the general formula (I).

[0009]

Embedded image

(Wherein A represents an aromatic ring residue which may have a substituent), and a charge control agent for developing an electrostatic charge image, and It exists in a toner and a charge giving material using the same.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The electrostatic charge image developing charge control agent of the present invention is characterized by being represented by barium sulfate or the above general formula (I). A in the general formula (I) represents an aromatic ring residue which may have a substituent. Examples of the aromatic ring residue include arylene groups such as a phenylene group, a naphthylene group and an anthrylene group, and a naphthylene group is particularly preferable. These may have one or more substituents in addition to the sulfonyl group, and as the substituent, a C _1-6 alkyl group, a halogen atom, a hydroxyl group, an amino group, a C _1-6 alkoxyl group, phenylamino Group, a methylamino group, a benzoylamino group, an acetylamino group and the like can be mentioned, and a hydroxyl group is particularly preferable. Further, it may have two or more kinds of substituents, and may have a plurality of the same substituents.

Specific examples of preferable compounds represented by the above general formula (I) include, but are not limited to, the exemplified compounds represented by the following structural formulas. .

[0013]

[Table 1]

Particularly, barium sulfate is preferable not only in terms of the required characteristics as described above, but also in terms of safety for the human body. Next, the case where the charge control agent of the present invention is used in toner will be described. The toner contains at least a charge control agent, a resin and a colorant. The resin to be contained in the toner can be selected from a wide range including known resins. For example, polystyrene, polychlorostyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer. Coal, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-
Ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate) Copolymers, styrene-ethyl methacrylate copolymers, styrene-butyl methacrylate copolymers, styrene-phenyl methacrylate copolymers, etc.), styrene-α-chloromethyl acrylate copolymers and styrene-acrylonitrile-acryl Styrene resins such as acid ester copolymers (styrene or homopolymers containing styrene substitutes), vinyl chloride resins, rosin-modified maleic acid resins, phenol resins, epoxy resins, polyester resins (saturated, unsaturated , Including low molecular weight polyethylene, There are molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin, etc., but as a particularly preferable resin for use in the present invention, styrene-acrylic acid ester copolymer is used. Examples thereof include polymers, styrene-methacrylic acid ester copolymers, polyester resins and epoxy resins. Further, the above-mentioned resins are not limited to being used alone, and may be used in combination of two or more.

The colorant to be contained in the toner can be selected from a wide range including known ones, and examples thereof include carbon black, lamp black, iron black, ultramarine blue, nigrosine dye, aniline blue, phthalocyanine blue, phthalocyanine green and Hansa yellow. , Chrome yellow,
Examples include rose bengal, triarylmethane dyes, monoazo dyes, disazo dyes and pigments.

The compound represented by the general formula (I) is white and may be contained in color toners such as blue, red and yellow. In this case, a coloring agent composed of a dye or pigment having a corresponding color tone. To use. The content of the colorant is preferably 3 to 20 parts by weight based on 100 parts by weight of the resin. Examples of a method for incorporating the compound represented by the general formula (I) into the toner include an internal addition method in which the toner is added and mixed together with the resin, and an external addition method in which the toner particles are added and mixed after formation. The internal addition method is more general and preferred. The content of the compound represented by formula (I) in the toner is preferably 0.1 to 20 parts by weight, more preferably 0.1 to 15 parts by weight, and still more preferably 100 parts by weight of the resin. 0.5 to 5 parts by weight. If the content of the compound represented by the general formula (I) is too small, the effect of improving the chargeability is not improved, and if the content is too large, the quality of the toner is deteriorated.

The toner of the present invention contains, in addition to the compound represented by the general formula (I), other charge control agents, including known ones, such as nigrosine dye, quaternary ammonium salt, and the like. A metal complex compound or the like may be contained. Further, other known additives such as, for example,
The electrical properties of the toner can be controlled by adding a conductor such as a solid electrolyte, a polymer electrolyte, a charge transfer complex, or a metal oxide such as tin oxide, a semiconductor or a ferroelectric or a magnetic substance. In addition, various plasticizers such as low molecular weight olefin polymers and auxiliary agents such as release agents may be added to the toner for the purpose of adjusting thermal characteristics, physical characteristics and the like. Further, by adding a fine powder of TiO ₂ , Al ₂ O ₃ , SiO ₂ or the like to the toner particles and coating the surface of the toner particles with these powders, the fluidity and aggregation resistance of the toner can be improved.

The charge control agent of the present invention is particularly preferably used for negatively chargeable toner. As a method for producing a toner, each of the above components may be kneaded with a kneader or the like, cooled, pulverized and classified. In addition to the two-component developer, the toner of the present invention can be applied to so-called one-component developer (magnetic toner or non-magnetic toner) such as encapsulated toner, polymerized toner and magnetite-containing toner. The average particle size of the toner is preferably 5 to 20 μm.

As a carrier which is mixed with the toner of the present invention to form a developer, a known iron powder-based, ferrite-based, magnetite-based carrier or the like magnetic substance, or a resin coated on the surface thereof or a magnetic resin is used. A carrier can be used. As the coating resin for the resin coating carrier, generally known styrene resin, acrylic resin, styrene-acrylic copolymer resin, silicone resin, modified silicone resin, fluorine resin, or a mixture of these resins is used. It can be used, but is not limited to these. The average particle size of the carrier is not particularly limited, but preferably has an average particle size of 10 to 200 µm. 5 parts by weight of these carriers are used for 1 part by weight of the toner.
It is preferable to use 100 parts by weight.

Next, the case where the charge control agent of the present invention is used as a charge-giving material will be described. The charge imparting material has the compound represented by the general formula (I) on at least a part of its surface. A coating solution obtained by dissolving or dispersing the charge control agent of the present invention in a solvent or a dispersion medium together with a binder resin, if necessary, is applied to the base material of the charge imparting material by dipping, spraying, brush coating or the like. Alternatively, when the base material is in the form of carrier particles, it is dipped and mixed with the above coating solution and dried, or a method such as coating with a fluidized bed of a direct mixture with the base material is applied onto the base material. The charge imparting material of the present invention can be obtained by forming a coating layer containing the charge control agent. Alternatively, a charge-imparting material may be obtained by directly melting and kneading the binder resin and the charge control agent and extruding and laminating the charge control agent on a base material. Further, the charge control agent may be contained in a moldable resin, and the charge control agent may be formed into a shape of carrier particles, a developing sleeve, or a layer forming blade to serve as a charge imparting material.

[0021]

The present invention will be described in more detail with reference to the following examples. In the following examples, “parts” simply means “parts by weight”. Example-1

[0022]

[Table 2] Polyester resin (FC-023 manufactured by Mitsubishi Rayon Co., Ltd.) 100 parts Carbon black (MA-100 manufactured by Mitsubishi Chemical Co., Ltd.) 4 parts Barium sulfate 3 parts

The above materials were blended and kneaded, pulverized and classified to obtain a black toner having an average particle diameter of 9 μm. 5 parts of this toner and 100 parts of a ferrite carrier having an average particle diameter of about 100 μm were mixed and stirred to prepare a developer. Next, when this developer was actually copied by a copying machine using selenium as a photoreceptor, a clear copy was obtained.

Example-2 The same procedure as in Example-1 was carried out except that 3 parts of Exemplified Compound (1) was used as the charge control agent, and good copies were obtained in the same manner as in Example-1. Example-3 A good copy was obtained in the same manner as in Example-1, except that 3 parts of Exemplified Compound (3) was used as a charge control agent.

Example-4 The same procedure as in Example-1 was carried out except that 3 parts of Exemplified Compound (4) was used as the charge control agent, and good copies were obtained in the same manner as in Example-1. Example-5 The same procedure as in Example-1 was carried out except that 3 parts of Exemplified Compound (6) was used as the charge control agent, and good copies were obtained in the same manner as in Example-1.

Example-6 The same procedure as in Example-1 was carried out except that 3 parts of Exemplified Compound (8) was used as a charge control agent, and good copies were obtained in the same manner as in Example-1. Example-7 A good copy was obtained in the same manner as in Example-1, except that 3 parts of the exemplified compound (10) was used as a charge control agent.

Example-8 The same procedure as in Example-1 was carried out except that 3 parts of Exemplified Compound (12) was used as the charge control agent, and good copies were obtained in the same manner as in Example-1. Example-9 The same procedure as in Example-1 was carried out except that 3 parts of Exemplified Compound (13) was used as a charge control agent, and good copies were obtained in the same manner as in Example-1.

Example-10 The same procedure as in Example-1 was carried out except that 3 parts of Exemplified Compound (14) was used as the charge control agent, and good copies were obtained in the same manner as in Example-1. Examples-11-14

[0029]

[Table 3] Polyester resin 100 parts Carbon black 4 parts Table-1 charge control agent 3 parts

0.5 g of a black toner obtained by compounding and kneading the above materials, pulverizing and classifying and 9.5 g of a carrier composed of ferrite powder were put in a glass bottle and shaken for 5 minutes, and then the charge amount was measured by a blow-off method. did.

[0031]

[Table 4]

[0032]

EFFECT OF THE INVENTION The electrostatic charge image developing toner and the charge-imparting material using the electrostatic charge image developing charge control of the present invention have excellent safety and excellent charge stability, and copy stains due to continuous copying. It is a high-quality electrostatic image developing toner and a charge-giving material that does not generate a charge.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masako Takeuchi 1000 Kamoshita-cho, Aoba-ku, Yokohama-shi, Kanagawa Prefecture Mitsubishi Chemical Research Institute Yokohama Research Laboratory

Claims (3)

[Claims] 1. Barium sulfate or the general formula (I): (In the formula, A represents an aromatic ring residue which may have a substituent.) A charge control agent for electrostatic image development, which is a compound represented by the formula. 2. An electrostatic image developing toner comprising a resin, a colorant, and the electrostatic image developing charge control agent according to claim 1. 3. A charge providing material for developing an electrostatic image, comprising the charge control agent for developing an electrostatic image according to claim 1 on at least a part of the surface of the base material.