JPS60123857A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To obtain a toner for developing an electrostatic charge image having excellent cleaning performance with higher density and higher image quality by maintaining the respective average grain sizes and mixing ratios of the 1st toner consisting of spherical particles and the 2nd toner consisting of shapeless particles within a specific value. CONSTITUTION:The difference between respective weight average grain sizes is maintained within 5mum and the ratio of both toners is made within a 100:60- 100:10 ratio and if necessary a fluidizing agent, etc. are added and mixed to and with the toner in the stage of mixing the spherical toner particles obtd. by subjecting shapeless toner particles to a spheroidizing treatment by which the toner particles are scattered and are acted with hot wind, or spraying method by which the resin soln. dispersed and mixed with the toner particles is sprayed and dried or a granulation polymn. method by which the polymerizable compsn. consisting of the monomer dispersed and mixed with the toner component is suspension-polymerized and the shapeless toner particles obtd. by adding the toner component into a binder resin and cooling and grinding the mixture after melting by heating.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention provides a toner KgM for developing electrostatic images formed in electrophotography, electrostatic printing, electrostatic recording, etc.
It is something to do.

[Prior art]

Electrostatic charge edge development is a process in which charged toner particles are attached to the surface of a support using electrostatic attraction, thereby making them visible.

It is preferable to use a dry developing method to develop an electrostatic image. There is a so-called one-component toner which is used alone without being mixed with a magnetic toner containing a magnetic toner.

In the toner of such a developer, the demand for high image quality, that is, high density, has been increasing in recent years.

In order to form visible images with high sharpness, high resolution, and high gradation, it is essential that the toner itself has excellent fluidity. To improve the fluidity of toner, there is a method of adding a fluidizing agent such as hydrophobic silica, but when the amount of fluidizing agent added is large, the electrostatic charging support is 9. Electrostatic charge □□
□ Cleaning the optical surface of the support with rubber solade: If it breaks, the blade may be severely abraded and cause a cleaning failure. Furthermore, since hydrophobic silica itself has strong charge control properties, if a large amount is added, it may not be possible to adjust the densities of the toner particles to a desired value. Therefore, the fluidizing agent cannot be added without limit. On the other hand, another method for improving the fluidity of toner particles is to make toner particles spherical. This spheroidization is achieved by, for example, a method in which irregularly shaped toner particles are treated with hot air.

This can be done by solution polymerization method, suspension polymerization method, emulsion polymerization method, solution melting method, etc. However, although spherical toner particles have excellent fluidity, they have a relatively large adhesion force to the electrostatic image support, and therefore it is difficult to perform sufficient cleaning with Shire P in the cleaning process, and the electrostatic charge This method has the problem that toner remains on the image support and stains occur on the image area.

For this reason, in order to improve the fluidity of toner and improve the cleaning performance.

A toner composed of a mixture of spherical particles and irregularly shaped particles has been proposed. According to the toner composed of these nine aggregates, the fluidity of the toner and developer is maintained well due to the effect of the single spherical particles, and the amorphous particles are more easily cleaned by the blade than the spherical particles. However, these amorphous particles do not have the same performance as spherical particles. However, it has been found that it is not always sufficient for the toner to be a mere mixture of spherical particles and irregularly shaped particles. That is.

When the weight average particle size of spherical particles and the weight average particle size of irregularly shaped particles are different in a toner, when the toner is used as a one-component developer, particles with a smaller weight average particle size are selectively used. When used as a crab component type developer, particles with larger weight average particle diameters will selectively contribute to development. The content ratio of regular particles changes, and stable IilI formation characteristics cannot be obtained. Furthermore, depending on the content ratio of spherical particles and amorphous particles in the toner, a sufficiently good cleaning performance may not be obtained.

It has also been found that as the number of times image formation increases, toner remains on the surface of the electrostatic image support, causing stains on the resulting image and making it impossible to obtain a good image. .

[Purpose of the invention]

The present invention has been made based on the above-mentioned circumstances, and its purpose is to achieve high density and high image quality, and furthermore, to have excellent cleaning performance and maintain a stable image without stains for a long period of time. An object of the present invention is to provide a toner for developing an electrostatic image that can be obtained.

[Structure of the invention]

The above purpose is to provide a first toner powder composed of one spherical particle;
The mixture is composed of a second toner powder composed of irregularly shaped particles, and the difference between the weight average particle diameter of the first toner powder and the weight average particle diameter of the second toner powder is within 5 μmJM. B. This is achieved by a toner for developing an electrostatic image, characterized in that the weight ratio of the second toner powder and the first toner powder is 100:60 to 100:10.

The present invention will be specifically explained below.

゛ In the present invention, both the first toner powder composed of spherical particles and the second toner powder composed of amorphous particles are used, such that the difference in the weight average particle diameter of each toner powder is within 5 μm. , the second toner powder and the first toner powder are mixed so that the weight ratio is within the range of 100:60 to 100:10, and if necessary, a fluidizing agent or a fatty acid metal salt is added to stabilize the mixture. Used as toner for developing charge images.

In the above, both the first toner powder and the second toner powder are powder particles containing a coloring agent and additives added as necessary, and are considered to be magnetic toners. In this case, a magnetic substance is contained in some or all of the coloring agent. The first toner powder is produced by a spheroidizing process in which irregularly shaped toner particles are scattered and heated with hot air, or by a spray drying method in which a resin solution in which toner components are dispersed and emulsified is sprayed and dried. It can be produced by a granulation polymerization method in which a polymer composition composed of monomers with beneficially mixed components is subjected to suspension polymerization. The 20th toner powder is manufactured by a normal toner manufacturing method in which toner components are added to Nononingu resin, heated to melt and knead, cooled, and then crushed and classified. be able to.

The weight average particle size of the first toner powder and the weight average particle size of the second toner powder are determined by the "Coulter Counter".
(manufactured by Coulter Electric Co., USA) with a diameter of 10
It is measured using a 0 μm aperture tube. The weight average particle size of the first toner powder and the weight average particle size of the second toner powder may be larger, and the difference may be within 5 μm, preferably within 2 μm. The weight average particle size of these particles is preferably within the range of 6 to 15 μm, and the entire mixture is within the range of 6 to 10 μm.
It is preferable that it is within the range of . The weight ratio of the second toner powder and the first toner powder is 100:60 to 100:1.
It is 0. In the above, if the difference between the weight average particle size of the first toner powder and the weight average particle size of the second toner powder exceeds 5 μm, one of the toner powders is selectively used.
Since the characteristics of the developer change as the developer comes to contribute to the image, stable image forming characteristics cannot be obtained over a long period of time. Furthermore, if the amount of the first toner powder mixed with 100 parts by weight of the second toner powder exceeds 60 parts by weight, the cleaning performance will decrease as the formation of both edges is repeated, and the cleaning performance will be good for a long period of time. It may be difficult to achieve this, and conversely, if the mixed amount of the first toner powder is 10
If the weight is less than 6 μm, the fluidity will decrease and it will not be possible to obtain a practically sufficient particle size.Furthermore, if the weight average particle size of the entire toner is less than 6 μm, the cleaning performance will be significantly reduced, and the toner as a whole will be 1 [If the average particle diameter exceeds 10 μm, the solvency becomes poor.

It is preferable that the first toner powder and the second toner powder have the same characteristics except for the form of one particle, and therefore the binder and toner components or compositions, etc. are preferably the same. preferable.

As the binder, conventionally used binders can be used as they are, but thermoplastic resins are preferably used. Specifically, polystyrene, polyvinyltoluene, styrene-butadiene copolymer, styrene-
Acrylic acid ester copolymers, polymers or copolymers of styrene or its substituted products such as styrene-maleic anhydride copolymers, polyester resins, acrylic resins, 1,000 silane resins, polyamide resins, ionomer resins, ketone resins, Terpene resin, phenol-modified terpene resin, Logi/, Logi/modified resin, maleic acid-modified phenol resin, petroleum resin, starch graft polymer, polyvinyl alcohol, polyvinylpyrrolidone, etc. can be used alone or in combination. Among these, styrene resins and polyester resins are particularly preferred. The ratio of the binder to the total amount of toner powder is in the range of 20 to 99% by weight.

The toner components constituting the toner powder together with the above-mentioned inder include a layer coloring agent, a magnetic material in the case of a magnetic toner, and additives added as necessary.

Coloring agents include car bomb black, nigrosine dye (C, 1, A304.15B), aniline blue (C,
1, A30405), Calco Oil Blue (C, I.

Aazoec B1ue3), Chrome Ie o-(,C
, 1, A14090), ultramarine blue (C,
1, 77103), DuPont Oil Red (C, 1,
426105), quinoline yellow (C, 1, A470
05), methylene blue chloride (C,1,A320
15), 7 Talocyanine Blue (C, 1, A74160
), 72 Kite Green Oxalate (C, 1, A42
000), lamp black (C, l', A77266J
, Rose Bengal (C,I.

A45435), mixtures thereof, and others. These colorants must be contained in a sufficient proportion to form a visible image with sufficient concentration, and are usually present in an amount of about 11 to 20 parts by weight per 100 parts by weight of the binder. .

Specific examples of the magnetic material include metal powders such as cobalt, iron, and nickel, aluminum, cobalt, copper, iron, lead,
Metal alloys and mixtures thereof such as nickel, magnesium, tin, zinc, gold, silver, selenium, titanium, tungsten, zirconium, magnetic metal oxides such as aluminum oxide, iron oxide, nickel oxide, and metal compounds containing gold, Mention may be made of ferromagnetic ferrites and mixtures thereof. These magnetic substances are made into fine powder and dispersed in the toner particles, and the ratio thereof is 10% to the total amount of toner powder.
-80% by weight, preferably 35-65]ILt. Note that the magnetic material may also exhibit an effect as a coloring agent.

In the present invention, it is preferable to further add and mix a fluidizing agent and a fatty acid metal salt to the mixture of the first toner powder and the second toner powder to form the toner tl-. Examples of the fluidizing agent include fine powders such as silica, alumina, titanium oxide, vinylidene fluoride, and fluorinated GK powder particles, and the ratio of these fluidizing agents to the total amount of toner powder is 0.01 to 2. It is preferable that it is Oxt%. Addition of this fluidizing agent improves the fluidity of the toner, improving developability, and also reduces the adhesion of residual toner to the electrostatic image support, improving cleaning performance. . The above proportion of this fluidizing agent is 0.01% by weight.
If the amount is less than 2.0% by weight, the effect of the addition will be small; conversely, if it exceeds 2.0% by weight, the surface of the electrostatic image support will be easily scratched, resulting in poor cleaning, and the blade will be severely worn, resulting in poor cleaning performance. Or worse. Examples of fatty acid metal salts include metal salts of maleic acid and zinc, magnesium, calcium, etc.; stearic acid and zinc, cadmium, lead, iron, nickel, iron, copper,
Metal salts with aluminum, magnesium, etc.; dibasic stearin lead; oleic acid with zinc, magnesium, iron,
Metal salts with cobalt, copper, lead, calcium, etc.; metal salts with palmitic acid and zinc, aluminum, calcium, etc.;
Lead caprylate; lead cabroate; metal salts of linoleic acid with zinc, cobalt, etc.; metal salts of calcium ricinoleate with silicic acid and zinc, cadmium, etc., and mixtures thereof. Particularly preferred is zinc stearate. The ratio of these fatty acid metal salts to the total amount of toner powder is preferably 0.01 to 2.0 weight. The addition of the fatty acid metal salt reduces friction between the residual toner and the electrostatic image support, improving cleaning performance. When the proportion of the fatty acid metal salt is less than 0.01% by weight, the effect of added calories is small;
．． In the present invention, when the toner contains a magnetic material, the toner is treated as a so-called one-component developer used as the developer. The toner containing no toner is combined with a carrier to form a so-called two-component developer. Here, the carrier may be known iron powder, glass peas, etc., and the conductive carrier may be oxidized or Unoxidized iron powder is preferably used, and as the insulating carrier, the surface of carrier core particles made of a magnetic material such as iron, nickel, iron, ferrite, etc. is coated with an insulating resin. [Effects of the Invention] The toner for developing an electrostatic image of the present invention is preferably made of spherical particles.
and a second toner powder consisting of irregularly shaped particles, and in this mixture, a second toner powder consisting of irregularly shaped particles and a first toner powder consisting of spherical particles
The weight ratio of toner powder is 100:60 to 100:10.
Since the spherical particles follow the amorphous particles well and are sufficiently cleaned, no residual toner is generated on the electrostatic image support, resulting in a clean and clear image. It can be obtained stably over a long period of time, and due to the effect of the spherical particles, the fluidity of the toner as a whole is maintained well, the amount of toner adhesion is sufficient, and the practical diameter is within 5 μm even if there is a difference. Since the first toner powder and the second toner powder have the same behavior and contribute equally to the development, it is possible that only one toner powder is selectively used. Since the first toner powder and the second toner powder are not consumed in the toner, even when images are repeatedly formed many times, the content of the first toner powder and the second toner powder in the toner remains constant. Since the ratio does not change and the toner characteristics are stably maintained in the desired state, stable image forming characteristics can be obtained over a long period of time.Examples Next, examples of the present invention will be described. The present invention is not limited thereto.Example 1 (a) Production of first toner powder Stirring: 70 parts by weight Methacrylate yv@methyl 20 parts by weight Methacrylic 1ln-butyl 10 parts by weight Carbon black [Raven 1250J (manufactured by Columbia) 10
Parts by weight Azobisisobutyronitrile 3 parts by weight Low softening point polypropylene "Viscoll 550P" (manufactured by Sanyo Chemical Co., Ltd.) 3
Parts by weight or more of the materials were thoroughly mixed using a gold stirrer to prepare a polymerizable composition containing gold as a polymerization initiator t-1111#. This O polymerizable composition was added to an aqueous polyvinyl alcohol solution with a concentration of 1.25 weight by stirring at a rotation speed of 650 ° r, p, m using a stirrer [TK homogenizer] (Tokkyo Ni Co., Ltd.), Then put it in a regular stirrer (b)
Temperature 60℃ while stirring at rotation number 10Or, p, m,
Allow the polymerization reaction to take place for 8 hours. After the polymerization reaction was completed, the reaction system was cooled, treated with concentrated hydrochloric acid, dehydrated, washed and dried to produce a first toner powder consisting of spherical particles with an average particle size of 8.5.

(B) Production of second toner powder 70 parts by weight of styrene, 2 parts by weight of methyl methacrylate, and 1 part by weight of 10 parts by weight of Meta-L-Krylic-butyl, obtained by copolymerizing 100 parts by weight of 100 parts by weight of carphone Plaque [H, aven 1250J 10 parts by weight Low softening point polypropylene [Viscol 550f'4 3 parts by weight or more of the substance are mixed, and heavy electromagnetic average particles are produced by a normal toner manufacturing method through the steps of melting, cross-mixing, cooling, pulverization and classification. A 20th toner powder consisting of amorphous particles having a diameter of 8.5 μm was completely produced.

50 parts by weight of the above first toner powder and 100 fU parts of M42 toner powder were mixed, and then 1 part hydrophobic silica "Aerosil 972J (manufactured by Nippon Aerosil Co., Ltd.) 0.6Xt" and stearin were added to the total amount of toner powder. acid zinc 0.1
% by weight was added to produce a toner for developing an electrostatic image.

This toner for developing an electrostatic image is mixed with a carrier made of iron powder coated with resin, and the toner concentration is 2% by weight.
A developer with a toner charge amount of 25±1μ (7?) was prepared.

This is tr, developer 1.

Using this developer 1, an electrophotographic copying machine "U-Bix3000" equipped with a cleaning blade made of rubber
(manufactured by Kotaro Photo Industry Co., Ltd.), an image forming test was conducted to determine the amount of primary adhesion of toner on the surface of the photoreceptor drum, image 1.
The L resolution and cleaning properties were investigated. Here, the primary adhesion amount of toner is determined by the amount of toner adhesion per unit area at the point where the so-called solid black potential is 800 mm.In addition, to check the fluidity of the toner, "Tap Denser" (manufactured by Seishin Enterprise Co., Ltd.) is used. This increases the quietness and density of the toner.

This quietness density is the value obtained by measuring the weight of each roll with a diameter of 28 wm and a volume of 100 mm, which is loosely packed with a sample through an IQQ mesh sieve from above. The higher the particle size, the quieter the density. Result t-
Shown in Table 1.

In Table 1, "D" in the "Cleanability" column indicates that no cleaning defects occurred, and "x" indicates that no cleaning defects occurred.
indicates that a cleaning failure has occurred. In addition, "mixing ratio" refers to the second toner powder and the first toner powder.
represents the weight percentage of toner powder.

Examples 2 to 7 and Comparative Examples 1 to 5 The weight average particle size of the first toner powder, the weight average particle size of the second toner powder, and the mixing ratio of the second toner powder and the toner powder of coffin 1 were Developers 2 to 7 and Comparative Developers 1 to 5 were prepared in the same manner as in Example 1, except that the values shown in the table were used, and image formation tests were conducted on each of these developers in the same manner. The results are also shown in Figure 1.

Example 8 (a) Production of first toner powder Styrene 45 parts by weight Triethylene glycol dimethacrylate') 0.4 parts by weight Mavico Black [BL-5004 (triiron tetroxide powder) (Titan Kogyo Co., Ltd. Ai 55 parts by weight) parts [Nigrosynpase EXJ (manufactured by Orient Kogyo Co., Ltd.) 1.0 weight 1 part Azobisin butyronitrile 1.5 parts by weight or more 5
j was treated in the same manner as in Example 1 to obtain a weight average particle size of 8.5.
A first toner powder consisting of μm spherical particles was produced.

(b) 45 parts by weight of fA styrene of the second toner powder A second toner powder consisting of amorphous particles having a weight average particle size of 8.5 μIn was produced in the same manner.

40 parts by weight of the above first toner powder and 100 parts by weight of the second toner powder were mixed, and then 1 part hydrophobic silica [Aerosil IT-972J 0.3 weight value and 0.1 part zinc stearate] were added to the total amount of toner powder. A one-component transparent image developing toner was produced by adding heavy toner. This toner'
5c "Developer 8".

Using this developer 8, an electrophotographic copying machine for magnetic toner [U-B
An image formation test similar to that in Example 1 was conducted using ixTJ (manufactured by Konishiroku Photo Industry Co., Ltd.). The results are also shown in Table 1.

Comparative Examples 6 and 7 Comparative developer 6 was prepared in the same manner as in Example 8, except that the mixing ratio of the second toner powder and the first toner powder was set to the value shown in Table 1.
and 7 were prepared, and an image forming test was conducted in the same manner as in Example 8 for each of these developers. The results are also shown in Table 1.

As can be understood from the results in Table 1, Developers 1 to 8 using the toner of the present invention were excellent in all of cleaning properties, fluidity, image density, and resolution. On the other hand, Comparative Developers 1, 4, and 6 had poor long-term cleaning properties, Comparative Developers 2.3 and 7 had low fluidity and poor image density and resolution, and Comparative Developer 5 had poor cleaning performance. Accordingly, as the number of copies increases, the content ratio of the first toner powder decreases, resulting in a decrease in image density.

Claims (1)

[Scope of Claims] l) The weight ratio of the first toner powder consisting of spherical particles, the second toner powder and the first toner powder is 100:60 to 100:1G. The electrostatic charge described in item 1 of this range is 1#! Toner for development. 8) The toner for electrostatic charge iron development according to claim 1 or 2, wherein the weight average value of the mixture is 6 to 10 μm. 4) The electrostatic charge developing toner according to claims 1 to 8', which contains a fluidizing agent. 5) The toner for developing electrostatic images according to claim 4, wherein the fluidizing agent is selected from silica, alumina, wk titanium vinylidene fluoride, and fluorinated fine powder particles. 6) Fluidization stiffness content ratio is 0 with respect to the total amount of toner powder
．． 01 to 2.0% by weight of the toner for developing electrostatic images according to claim 4 or 5. 7) The toner for electrostatic charge images fjL images according to the falling force λ- of claims 1 to 6, which further contains a fatty acid metal salt. 8) The toner for electrostatic charge-aware development according to claim 7, wherein the content of the fatty acid metal salt is 0.01 to 2.0% by weight based on the total amount of the toner powder.