JPH02171758A - One-component developer - Google Patents

Abstract

PURPOSE:To obtain sharp images stably over a long period of time by incorporating the polyoxybenzalkonium salt of a cationic surfactant into a toner. CONSTITUTION:This developer contains the polyoxybenzalkonium salt expressed by the formula I in the binder resin. In the formula I, R denotes the formula II or III; X denotes Cl or Br; (n)=1 to 30, (m)=1 to 30. The compd. expressed by the formula I is preferably used in the form of the grain sizes ranging 10 to 0.01mu, more preferably 5 to 0.1mu average grain size in the prepn. of the toner. The compd. is used in the content ranging 0.1 to 20pts.wt., more preferably 0.5 to 10pts.wt. per 100pts.wt. binder resin. The sharp images are obtd. stably over a long period of time in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to electrophotographic developers, particularly dry-component developers.

[Prior Art] As a conventional electrophotographic method, US Pat. No. 2,297. H1 specification, Japanese Patent Publication No. 42-23910 (U.S. Patent No. 3)
゜f! 88.383) and Japanese Patent Publication No. 1973-247
Publication No. 48 (U.S. Patent No. 4,071,381)
Although a number of methods are known, generally using a photoconductive material to form an electrical latent image on a photoreceptor by various means, the latent image is then transferred to a toner. The toner image is developed into a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then fixed by heating, pressure, etc. to obtain a copy.

Various developing methods are known for making an electrostatic latent image visible using toner. For example, the magnetic brush method described in U.S. Pat. No. 2,874,083, and U.S. Pat.
The cascade development method described in the specification and No. 2 of the same
A large number of development methods are known, such as the powder cloud method, fur brush development method, and liquid development method described in No. 221778. Among these developing methods, the magnetic brush method, cascade method, liquid developing method, etc., which use a developer mainly consisting of toner and carrier, are in particular widely put into practical use.

Further, US Pat. No. 3,909,258 proposes a method of developing using electrically conductive magnetic toner. In this method, conductive magnetic toner is supported on a cylindrical conductive sleeve having magnetism inside, and is brought into contact with an electrostatic image to be developed. At this time, in the developing section, a conductive path is formed by the toner particles between the surface of the recording medium and the surface of the sleeve, and charges are guided from the sleeve to the toner particles through this conductive path, and between them and the image area of the electrostatic image. Toner particles adhere to the image area due to Coulomb force and are developed.

A developing method using high-resistance magnetic toner is a developing method that utilizes dielectric polarization of toner particles, and toner particles are triboelectrically charged by friction between toner particles or friction between toner particles and a sleeve, etc., and this is used as an electrostatic image. A method of developing by contacting a carrier is known.

Furthermore, in Japanese Unexamined Patent Publication No. 55-1885E1, etc., magnetic toner is coated extremely thinly on a sleeve, this is triboelectrically charged, and then this is brought very close to the electrostatic image so as to face it without coming into contact with the electrostatic image. A method of developing is proposed.

Further, a similar developing method using a non-magnetic single-component toner has also been proposed in Japanese Patent Laid-Open No. 143380/1983.

By the way, in the general one-component development method, it is said that the thickness of the toner layer on the sleeve must be made as thin as possible. This also applies when a carrier with a very small diameter is used in a two-component development system. Also, −
When a component developer with high electrical resistance is used, it is necessary to charge the toner with a developing device, so the toner layer thickness must be made extremely thin to uniformly charge the entire toner layer. It won't happen.

Various methods have been proposed as means for regulating the toner layer thickness. For example, there is a method in which a magnetic blade is placed opposite to the sleeve and the toner on the sleeve is pressed down by the blade to control the toner layer thickness.

However, in the past, when trying to obtain an image with a developing device using the above-mentioned toner layer thickness regulating means, a good toner thin layer could be formed on the sleeve at the initial stage, but a good thin layer of toner could be formed on the sleeve immediately after development. A thin layer may not be formed to the same extent as before development. This means that it is difficult for the toner to maintain a uniform amount of charge due to friction with the sleeve, and the cause of this is that as the toner near the sleeve repeatedly undergoes friction with the sleeve, the amount of charge increases. As a result, the amount of charge on the toner particles becomes non-uniform, which may cause a change in the electrostatic force between the toner and the sleeve. Such non-uniformly charged toner tends to cause problems such as development fog and scattering, which is particularly noticeable in environments where the amount of charge tends to increase, such as low temperature and low humidity.

In the present invention, by containing a polyoxybenzalkonium salt, which is a cationic surfactant, in the toner, the toner retains a sufficient and stable amount of charge from the initial stage when it rubs against the sleeve, and even after durability and changes in the environment. Since it is stable even when exposed to water, it is possible to provide clear images without blurring or scattering.

[Problems to be Solved by the Invention] The purpose of the present invention is to provide a new technique for controlling the charge of toner that overcomes such drawbacks. In the case of development, the amount of triboelectric charge between the toner and a toner carrier such as a sleeve is stable, the distribution of triboelectricity is sharp and uniform, and the amount of charge can be controlled to suit the developing system used. It's on offer. Another objective is to develop a developer that can develop and transfer faithfully to the latent image, i.e., there is no toner adhesion in the background area during development, no fogging, no toner scattering around the edges of the latent image, and high image quality. To provide a developer that provides high density and 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 does not cause changes in toner cohesiveness or charging characteristics.

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

Still another object is to provide a developer that does not stain, abrade, or scratch the electrostatic latent image surface and is easy to clean.

[Means and effects for solving the problems] The present invention is a one-component developer characterized by containing a compound represented by the following general formula (I) in a binder resin.

CI) Polyalkoxybenzalkonium Salt Generally, it is desirable that the above compound (I) be used in toner preparation as having an average particle size in the range of lθ to 0.01 g, preferably 5 to 0.1 g.

Furthermore, in the compound represented by the above general formula (I), n
It is desirable that m is 1 to 30, preferably 5 to 20. This means that the compound represented by the general formula (I) that satisfies this condition is thermally and temporally stable, has low hygroscopicity, This is because it has been found that when contained in a developer, it provides a developer with excellent electrophotographic properties.

Among the compounds represented by the general formula (I), those of the following structural formulas (1) to (2) are particularly preferably used because they provide good stability in environmental properties and developability.

Compound Methods for incorporating the above compound (1) into the developer include a method of adding it inside the developer and a method of adding it externally. When internally added, the amount of this compound used is determined by the type of binder resin, the presence or absence of additives used as necessary, and the toner manufacturing method including the dispersion method, and is uniquely limited. Although it is not necessary, it is preferably 0.1 to 20 parts by weight, more preferably 0.5 parts by weight per 100 parts by weight of the binder resin.
It is used in a range of 10 parts by weight.

When externally added, 0.01 parts by weight per 100 parts by weight of resin.
~10 parts by weight is preferred.

As the binder resin of the toner of the present invention, any suitable resin can be used, such as monopolymers of styrene and its substituted products such as polystyrene, poly-p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene; copolymer, styrene-vinyltoluene copolymer, styrene-acrylic ester copolymer, styrene-methacrylic ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer,
Styrene-vinyl methyl ether copolymer, styrene-
Styrenic copolymers such as vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; polyethylene, polypropylene, Polyvinyl chloride, phenolic resin, natural resin-modified phenolic resin, natural resin-modified maleic acid resin, acrylic ester resin, methacrylic ester resin, polyvinyl acetate, silicone resin,
Polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, terpene resin, chloroindene resin, petroleum resin, etc. can be used.

In the toner of the present invention, any suitable pigment or dye can be used as a coloring agent, such as known dyes such as carbon black, iron black, phthalocyanine blue, ultramarine blue, quinacridone, and benzidine yellow.

Furthermore, when the toner of the present invention is a magnetic toner, ferromagnetic elements and alloys and compounds containing these, such as magnetite, hematite, and ferrite, alloys and compounds of iron, cobalt, nickel, and manganese, and other ferromagnetic alloys. Magnetic powders conventionally known as magnetic materials such as carbon black, nigrosine, metal complex salts, colloidal silica powder, fluorine resins may be included for purposes such as charge control agents and prevention of agglomeration. Powder etc. may be added.

Furthermore, the toner of the present invention particularly comprises about 0.01 to 5% of colloidal silica powder, abrasive particles such as cerium oxide, etc.
It is preferably used in a mixture with lubricant particles such as about 0.01 to 5% of two-binary resin powder and metal salts of higher fatty acids.

To prepare the toner for developing an electrostatic image according to the present invention, the charge control agent according to the present invention is mixed with a vinyl or non-vinyl thermoplastic resin, a pigment or dye as a coloring agent, a magnetic material as necessary, Additives are thoroughly mixed using a ball mill or other mixer, and then melted, kneaded, and kneaded using a heat kneader such as a heated roll, niegu, or extruder to make the resins compatible with each other. Alternatively, a toner having an average particle size of 5 to 20 particles can be obtained by dispersing or dissolving the dye, cooling and solidifying it, and then crushing and classifying the dye.

The toner produced by such a method can be used for developing to visualize an electrostatic charge image in electrophotography, electrostatic recording, electrostatic printing, etc. by any conventionally known means, such as the following: It has excellent effects.

That is, the amount of frictional charge between toner particles is uniform, and the amount of charge can be easily controlled. In particular, even in environments where the amount of charge on the toner tends to increase, such as low temperature and low humidity, a stable amount of charge can be obtained that is not much different from that under normal temperature and normal humidity. In addition, the amount of triboelectric charge does not vary or decrease due to deterioration during use, and is extremely stable, so there is no development fog as described above.
Obstacles such as toner scattering and contamination of electrophotographic materials and copying machines are eliminated, and phenomena such as toner aggregation, clumping, and low-temperature flow during storage, which were major drawbacks in the past, do not occur, and it can be stored for a long time. It is a toner and also has excellent abrasion resistance, fixing properties, and adhesive properties of toner images.

[Example] The present invention will be specifically explained below with reference to an example, but this does not limit the present invention in any way. All parts in the following formulations are parts by weight.

Example 1 The above materials were thoroughly mixed in a blender and then kneaded with two rolls heated to 150°C. After the kneaded material was left to cool naturally, it was roughly pulverized using a cutter mill, then pulverized using a pulverizer using a jet stream, and further classified using an air classifier to obtain a fine powder with a volume average particle size of 12 l. The obtained 0 then the fine powder 1
00 parts and 0.5 parts of silica treated with silicone oil modified with a 7-mino group were mixed in a sample mill to prepare a -component magnetic toner. When this toner was applied to the NP-3525 copying machine for copying, clear images with no background blur or reverse fog were obtained.
10,000 copies of A-49 paper were made under an environment of 10% of the temperature, and there was no fogging or scattering, and high image density was obtained.

Comparative Example 1 A developer was obtained in the same manner as in Example 1, except that Compound (1) was not used, and an image was obtained in the same manner by performing development, transfer, and fixing. At room temperature and humidity, there was little fog, but the image density was low at 1.05, the line drawings were scattered, and the solid black was noticeably rough.When examining the durability, the density dropped to 0.74 after printing 10,000 sheets.

When an image was obtained under the conditions of 15° C./10%, the image density was as low as 0.95.

There was severe fogging, scattering, and roughness, and transfer defects were noticeable. I tried continuous image printing, but after about 10,000 images, the degree of exposure was 0.6.
5, making it impractical.

Example 2 A developer was obtained in the same manner as in Example 1, except that 3 parts of compound (1) was used instead of 2 parts of compound 0, and an image was obtained in the same manner by performing development, transfer, and fixing. The detailed results are shown in Table 1, and almost the same satisfactory results as in Example 1 were obtained.

Example 3 A developer was obtained in the same manner as in Example 1 except that 2 parts of Compound 0 was used instead of 2 parts of Compound 0, and an image was obtained in the same manner by performing development, transfer, and fixing. The detailed results are shown in Table 1, and almost the same satisfactory results as in Example 1 were obtained.

Example 4 A developer was obtained in the same manner as in Example 1 except that 2 parts of Compound 0 was used instead of 2 parts of Compound 0, and an image was obtained in the same manner by performing development, transfer, and fixing. The detailed results are shown in Table 1, and almost the same satisfactory results as in Example 1 were obtained.

Example 5 The above materials were thoroughly mixed using a blender and then kneaded using two rolls heated to 150°C. After allowing the mixture to cool naturally, it is roughly pulverized using a cutter mill, then pulverized using a pulverizer using a jet stream, and further classified using an air classifier to obtain a fine powder with a particle size of 5 to 20. Obtained.

Next, hydrophobic colloidal silica R was added to 100 parts of the fine powder.
-972 (manufactured by Nippon Aerosil Co., Ltd.) 0.4 part was mixed in a sample mill to prepare a - component magnetic toner. When this toner was applied to a commercially available copying machine (trade name: MP-1502° manufactured by Canon ■) and images were produced, good results almost the same as in Example 1 were obtained.

Example 6 In Example 5, instead of 2 parts of compound 0, compound 0
A developer was obtained in the same manner as in Example 5, except that 3 parts were used, and an image was obtained in the same manner by performing development, transfer, and fixing. The detailed results are shown in Table 1, and almost the same satisfactory results as in Example 5 were obtained.

Example 7 In Example 5, instead of 2 parts of compound 0, compound 0
A developer was obtained in the same manner as in Example 5, except that 2 parts were used, and images were obtained in the same manner by performing development, transfer, and fixing. The detailed results are shown in Table 1, and almost the same satisfactory results as in Example 5 were obtained.

Comparative Example 2 A developer was obtained in the same manner as in Example 5, except that 2 parts of benzyl-dibutyl-propylammonium chloride was used instead of 2 parts of Compound 0, and an image was obtained in the same manner.

At room temperature and humidity, there was little fogging, but the image density was low at 0.86, line drawings were scattered, and solid black was noticeably rough. Durability was investigated, and the density decreased to 0.58 after 10,000 sheets were printed. When an image was obtained under the conditions of 15°C/lO%, the image density was as low as 0.80, and there were severe scattering, fogging, roughness, and noticeable transfer defects. Continuous image printing was performed, but the density became 0.61 after 10,000 copies, making it unpractical. Table 1 shows the evaluation results of each Example and Comparative Example.

(The following is a blank space) [Effects of the Invention] As described above, according to the present invention, clear images can be stably obtained over a long period of time.

Claims (1)

[Scope of Claims] A one-component developer characterized by containing at least one of a colorant, a binder resin, and a cationic surfactant represented by the following general formula (I). (I) Polyalkoxybenzalkonium salt ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ [However, R is ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ or ▲ There are mathematical formulas, chemical formulas, tables, etc. ▼ X is Cl or Br be. n=1-30, m=1-30]