JPH026055B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a new toner and image forming method used in electrophotography, electrostatic recording, magnetic recording, etc. In electrophotography, an electrostatic latent image is first formed by utilizing the properties of photoconductors such as cadmium sulfide, polyvinylcarbazole, selenium, and zinc oxide. For example, applying a charge uniformly on the photoconductor layer,
Imagewise exposure is performed to form an electrostatic latent image, which is then developed with toner powder charged to the opposite polarity to that of the electrostatic latent image, and further transferred and fixed onto a transfer sheet as required. Among these devices, in the case of an apparatus having a transfer process, the remaining toner on the photoreceptor that has not been transferred to the transfer sheet is usually removed and the photoreceptor is used repeatedly. The remaining toner on the photoreceptor is generally removed by connecting a cleaning member to the photoreceptor, such as a blade cleaning method, a fur brush cleaning method, or a magnetic brush cleaning method. In this case, since the cleaning member is pressed against the photoreceptor with an appropriate pressure, the photoreceptor may be scratched or the toner may stick during repeated use. For example, Japanese Patent Application Laid-Open No. 47345/1983 proposes adding both a friction reducing substance and an abrasive substance to the toner in order to avoid the phenomenon that the toner sticks to the photoreceptor. Although this method is certainly effective in avoiding the toner sticking phenomenon, it has the following problems. In other words, if a friction-reducing substance is added to an extent that can avoid the toner sticking phenomenon, it becomes difficult to remove low electrical resistance substances such as paper dust and ozone adducts that are generated or adhered to the surface of the photoreceptor due to repeated use. However, there is a problem in that the latent image on the photoreceptor is significantly damaged by the low electrical resistance material, especially in a high temperature and high humidity environment. In addition, the amounts of the friction-reducing substance and the abrasive substance added are delicate, making it difficult to obtain a toner with stable characteristics. The present invention was achieved as a result of intensive research in view of the above circumstances. An object of the present invention is to provide a toner that is less likely to damage a photoreceptor. Another object of the present invention is to provide a toner and an image forming method that do not cause disturbance of latent images even under high temperature and high humidity environments. Furthermore, another object of the present invention is to provide a toner and an image forming method that allow easy cleaning of toner remaining after transfer on a photoreceptor and have abrasive ability. Another object of the present invention is to provide a toner and an image forming method that prevent toner from adhering to and fusing to a photoconductor and do not cause streak-like or dot-like contamination on a copied image. Furthermore, another object of the present invention is to provide a toner and an image forming method that prevent contamination of a developing sleeve and do not cause a decrease in image density during durability. Specifically, the present invention has a weight average molecular weight of 3000
~80000 and a boiling point n- of 5-60% by weight
Polyalkylene containing hexane extract is the resin component
It relates to a toner for developing an electrostatic image, characterized in that the content is 1 to 10 parts by weight per 100 parts by weight, and the toner has a dynamic friction coefficient of 0.20 to 0.50. Furthermore, the present invention forms an electrostatic charge image on a laminated OPC photoreceptor, and converts the formed electrostatic charge image into a material having a weight average molecular weight of 3000.
~80000 and a boiling point n- of 5-60% by weight
Polyalkylene containing hexane extract is the resin component
1 to 10 parts by weight per 100 parts by weight, and a toner for developing an electrostatic charge image having a coefficient of dynamic friction of 0.20 to 0.50 is visualized to form a visible image, and the formed visible image is transferred, The present invention relates to an image forming method characterized by cleaning the surface of a laminated OPC photoreceptor with a blade after transfer. In the toner of the present invention, since the toner particles themselves have appropriate abrasive properties as indicated by their coefficient of dynamic friction, their own abrasive ability does not affect the image on a photoreceptor having an appropriate surface hardness. It is possible to remove residual toner, low resistance substances, paper powder, etc. after transfer on the photoreceptor without causing any damage. Furthermore, by appropriately combining the coefficient of dynamic friction of the toner used in the present invention and the surface hardness of the photoreceptor, appropriate non-adhesiveness in the interaction between the photoreceptor and the toner can be achieved, thereby preventing scratches on the photoreceptor. It is presumed that it is possible to sufficiently remove the toner remaining after transfer without attaching the toner to the photoreceptor, thereby preventing the toner from firmly adhering to the photoreceptor and toner from fusing. Furthermore, the combination of a photoreceptor with a specific surface hardness and a toner with a specific dynamic friction coefficient,
The amount of additives added to assist abrasiveness or lubricity can be reduced to virtually zero or a very small amount, and it is also effective in preventing toner or additive filming that occurs on the photoreceptor. bring. The abrasive toner of the present invention also has the effect of preventing sleeve contamination upon contact with the developing sleeve and stabilizing the durable image density. The toner of the present invention preferably has a coefficient of dynamic friction of 0.20 to 0.50, preferably 0.20 to 0.45 when measured by the measuring method shown below. The toner of the present invention having such a specific coefficient of friction fully exhibits the abrasive ability endowed to the toner particles themselves without damaging the photoreceptor. Therefore, low-resistance substances and adhered toner on the photoreceptor are easily removed by the cleaner blade, thereby preventing disturbance of the latent image and poor cleaning caused by contaminants. If the coefficient of friction is too large, the surface of the photoreceptor is likely to be damaged, and the adhesion to the photoreceptor increases, making it impossible to achieve sufficient cleaning. On the other hand, if it is too small, the polishing effect will be insufficient. When the toner has the above-mentioned friction coefficient, the contact between the toner and the sleeve of the developing device is appropriate, the sleeve is not contaminated by the toner, and the durable image density is stabilized during durability, especially in a high temperature and high humidity environment. The coefficient of friction according to the present invention is defined as a value measured by the following measuring method. That is,
For example, a flat film made of styrene-methyl methacrylate resin with a hardness of 20 g, which corresponds to the surface layer of an OPC photoreceptor, is fixed on the sample stage of a HEIDON 14 type surface property measuring instrument (manufactured by Shinto Chemical). A polyurethane rubber blade (thickness 2
mm x width 10 mm x length 50 mm), apply a 100 g load from above, move the sample stage at a speed of 50 mm/min,
0.50 g of toner placed on the flat membrane is evenly applied onto the flat membrane. Next, a vertical load of 100 g was applied to the above toner layer through a quartz disk with a diameter of 15 mm, the sample stage was moved at a speed of 50 mm/min, and the static and dynamic frictional resistance forces generated at this time were measured.・Calculate the coefficient of dynamic friction. Magnetic powder and polyalkylene are particularly important components of the toner that provide a coefficient of friction within the above range. The present inventors have found that a polyalkylene having a weight average molecular weight within a specific range and containing a boiling point n-hexane extractable content within a certain range is preferable, as described below. In particular, the value of the boiling point n-hexane extract has a strong correlation with the friction coefficient of the toner of the present invention, and by controlling this boiling point n-hexane extract, various problems related to cleaning can be eliminated. This is what led to the discovery of the present invention. The polyalkylene contained in the toner of the present invention has a weight average molecular weight Mw of 3000 to 80000,
In addition, it is preferable that the content contains 5 to 60% of the boiling point n-hexane extract, and in particular, in order to better exhibit the above-mentioned effects, the weight average molecular weight Mw is 5000 to 5000.
60,000, and the boiling point n-hexane extract is 10
The one containing ~45% is good. Examples of the above polyalkylene include homopolymers such as polyethylene, polypropylene, polybutene, and polyhexene, copolymers such as ethylene-propylene copolymers and ethylene-butene copolymers, terpolymers of these and hexene, and terpolymers of these and hexene. Examples include thermally modified products. Particularly preferred are polypropylene and thermally modified products thereof. These polyalkylenes are preferably added in an amount of 1 to 20 parts by weight, preferably 1 to 10 parts by weight, per 100 parts by weight of the resin component. This is because, by containing such a polyalkylene, the toner surface has appropriate roughness and hardness, and the toner can maintain appropriate abrasiveness. As a result, the toner of the present invention can prevent the aforementioned disturbance of the latent image and image contamination due to deposits on the photoreceptor without damaging the photoreceptor. There are various methods for measuring the weight average molecular weight Mw, which results in slight differences in the values. Therefore, in the present invention, it is defined as a value measured by the following measuring method. That is, by gel permeation chromatography (GPC), 400 μ of a sample with a concentration of 0.1 wt% is injected at a temperature of 135°C, a solvent of o-dichlorobenzene (0.1% ionol added), and a measurement flow rate of 1.0 ml/min. . When measuring the molecular weight of a sample, a calibration curve prepared using a monodisperse polystyrene standard sample is used. In the measurement, the column is not limited in any way, but examples include A-80M manufactured by Syodex. Moreover, the boiling point n-hexane extractable fraction in the present invention is the proportion of a polymer portion soluble in boiling point n-hexane, and is measured as follows. That is, a certain weight (W ₁ g) of the polymer is weighed out, and using an extraction means such as a Soxhlet extractor,
The boiling point n-hexane soluble component in the polymer is removed, and the remaining unextracted sample is dried and weighed (W ₂ g). The amount of extract is calculated using the formula W ₁ −
Calculated using W ₂ /W ₁ ×100 (%). The toner used in the present invention is produced by nitrogen adsorption method.
BET specific surface area is 0.5 to 500 m ² /g, especially 50 to 400
m ² /g of nonmagnetic inorganic fine powder may be added. This is because the addition of such fine powder reduces the aforementioned disturbance of the latent image. This seems to be because such fine powder has a large specific surface area, so that the low-resistance substance adhering to the drum is adsorbed or adhered to its surface and removed. Examples of such non-magnetic inorganic fine powder include alumina, titanium dioxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, and diatomaceous earth. , silicon carbide, various inorganic oxide pigments, chromium oxide, cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silica fine powder, etc. Metal titanate, silicon carbide, cerium oxide and silica fine powder are particularly preferred. The silica fine powder referred to herein is a fine powder having Si--O--Si bonds, and includes both those manufactured by a dry method and those manufactured by a wet method.
Various conventionally known methods can be applied to produce fine silica powder by a wet method. For example, the decomposition of sodium silicate with an acid, shown in the general reaction formula, is Na ₂ O x SiO ₂ + HCl + H ₂ O → SiO ₂ * nH ₂ O + NaCl Others (the reaction formula is omitted below), ammonia salts or alkalis of sodium silicate Decomposition with salts, generation of alkaline earth metal silicate from sodium silicate, followed by decomposition with acid to form silicic acid, method of converting sodium silicate solution into silicic acid using ion exchange resin, natural silicic acid or There are methods such as using silicate. The silica fine powder referred to herein can be any of anhydrous silicon dioxide (silica) and other silicates such as aluminum silicate, sodium silicate, potassium silicate, magnesium silicate, and zinc silicate. The particle size is the average primary particle size,
It is preferably within the range of 0.01 to 2μ. Moreover, those containing 85 weight percent or more of SiO ₂ are preferable. The silica fine powder obtained by the dry process is so-called dry process silica or fumed silica, and is produced by a conventionally known technique. For example, this method utilizes the thermal decomposition oxidation reaction of silicon tetrachloride gas in an oxyhydrogen flame, and the basic reaction formula is as follows. SiCl ₄ +2H ₂ +O ₂ →SiO ₂ +4HCl In addition, in this manufacturing process, by using other metal halogen compounds such as aluminum chloride or titanium chloride together with silicon halogen compounds, composite fine powder of silica and other metal oxides can be obtained. It is also possible to obtain the body, and the present invention includes these as well. Its particle size is 0.001~2μ as the average primary particle size.
It is preferable that it is within the range of , particularly preferably
It is preferable to use silica fine powder within the range of 0.002 to 0.2μ. Specifically, these silica fine powders include:
There are various commercially available silicas, but those with hydrophobic groups on the surface are preferred, such as R-972 (manufactured by Aerosil), Taranox 500 (manufactured by Talco), other silane coupling agents, titanium coupling agents, silicone oil. , those treated with silicone oil or the like having an amine in the side chain are preferable. In particular, when the toner is positively chargeable, it is preferable to use positively chargeable silica fine powder, and when it is negatively chargeable, it is preferable to use negatively chargeable silica fine powder. Furthermore, the positively or negatively chargeable silica fine powder preferably has an absolute value of triboelectric charge of at least |10|μc/g, particularly preferably at least |30|μc/g, as determined by the following measurement. Positively charging silica will be described below as an example. Here, the positively chargeable silica fine powder is defined as follows. That is, 2 g of fine silica powder left overnight in an environment of 25°C and 50% to 60% RH, and carrier iron powder not coated with resin (for example, EFV200/Nippon Iron Powder Co., Ltd., which has a main particle size of 200 to 300 mesh).
300) in an aluminum pot with a volume of approximately 200 c.c. under the above-mentioned environment (by shaking it up and down approximately 50 times). The amount of triboelectric charge of fine silica powder is measured by the usual blow-off method using a cell. A fine silica powder whose triboelectric charge measured by this method is positive is defined as a positively charged fine silica powder. In order to obtain such positively charged silica fine powder, it is preferable to treat it with a coupling agent containing an amine or silicone oil. Such processing agents include, for example,

【table】

Aminosilane coupling agents such as [Table] and modified silicone oils having an amine in the side chain of the following formula are generally used. (In the formula, R ₁ represents hydrogen, an alkyl group, an aryl group, or an alkoxy group, and R ₂ represents an alkylene group,
or represents a phenylene group, and R ₃ and R ₄ represent hydrogen, an alkyl group or an aryl group. However, the above alkyl group, aryl group, alkylene group, and phenylene group may contain an amine, or may have a substituent such as halogen within a range that does not impair chargeability. ) Examples of such silicone oils include the following:

[Table] In the present invention, the amine equivalent is the equivalent per amine (g/eqiv), which is the value obtained by dividing the molecular weight by the number of amines per molecule. Preferably, positively chargeable or negatively chargeable silica fine powder exhibits a degree of hydrophobicity in the range of 30 to 80 as measured by methanol titration test.
For such hydrophobic treatment, a conventionally known hydrophobization method is used, and is imparted by treatment with an organosilicon compound that reacts with or physically adsorbs silica fine powder. A preferred method is to treat fine silica powder with an organosilicon compound after treating it with a treatment agent such as the silane coupling agent described above, or at the same time as treating it with a treatment agent such as a silane coupling agent. Examples of such organosilicon compounds are hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, trimethylethoxysilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, allyl phenyldichlorosilane, benzyldimethylchlorosilane. Silane, bromomethyldimethylchlorosilane, α-chloroethyltrichlorosilane, p-chloroethyltrichlorosilane, chloromethyldimethylchlorosilane, triorganosilylmercaptan, trimethylsilylcaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, and
Dimethylethoxysilane, dimethyldimethoxysilane, diphenyldiethoxysilane, hexamethyldisiloxane, 1,3-divinyltetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and 2 to 12 siloxanes per molecule. There is dimethylpolysiloxane, etc., which has a unit and each unit located at the end contains one hydroxyl group bonded to Si. These may be used alone or in a mixture of two or more. Note that the methanol titration test here is an experimental test to confirm the degree of hydrophobization of the silica fine powder having a hydrophobized surface. The "methanol titration test" specified herein for evaluating the degree of hydrophobicity of treated silica fine powder is conducted as follows. Test silica fine powder
Add 0.2 g to 50 ml of water in a 250 ml Erlenmeyer flask. Methanol is titrated from the biuret until all of the silica is wetted. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed when the entire amount of fine silica powder is suspended in the liquid, and the degree of hydrophobization is expressed as the percentage of methanol in the liquid mixture of methanol and water when the end point is reached. In addition, the applied amount of these silica fine powders is effective when the amount is 0.01 to 20% based on the weight of the developer, and it is especially preferable to use positive or Shows negative chargeability. Regarding the preferred form of addition, it is preferable that 0.01 to 3% by weight of treated silica fine powder based on the weight of the developer be attached to the surface of the toner particles. The binder resin for the toner used in the present invention is as follows:
Monopolymers of styrene and its substituted products such as polystyrene, poly p-chlorostyrene, and polyvinyltoluene; styrene-p-chlorostyrene copolymers, styrene-propylene copolymers, styrene-
Vinyl toluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer,
Styrene-butyl acrylate copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene- α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer,
Styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile
Styrenic copolymers such as indene copolymer, styrene-maleic acid copolymer, and styrene-maleic ester copolymer; polymethyl methacrylate, polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester , polyurethane, polyamide, epoxy resin, polyvinyl butyral, polyamide, polyacrylic acid resin, rosin, modified rosin, terpene resin, phenolic resin, aliphatic or alicyclic hydrocarbon resin, aromatic petroleum resin, chlorinated paraffin, paraffin Wax, carnauba wax, etc. can be used alone or in combination. If necessary, conventionally known carbon black, copper phthalocyanine iron black, etc. can be used as coloring materials for the toner used in the present invention, and all conventionally known positive or negative charge control agents can be used in the present invention. It is. Furthermore, the toner of the invention may contain lubricants, conductivity imparting agents, fixing aids, etc., such as polytetrafluoroethylene powder, polyvinylidene fluoride powder, metal salts of higher fatty acids, carbon black, etc., as necessary.
Conductive tin oxide or the like may be added. Furthermore, the toner of the present invention has a volume resistivity of 10 ¹⁰ Ω.
cm or more, especially 10 ¹² Ωcm or more. The volume resistivity mentioned here is calculated by molding the toner at a pressure of 100Kg/cm ² and applying an electric field of 100V/cm to it.
It is defined as a value converted from the current value one minute after application. Furthermore, the toner of the present invention can be used as a developer for electrical latent images by mixing with carrier particles such as iron powder, glass beads, nickel powder, and ferrite powder, if necessary. Further, the present invention may contain magnetic powder as necessary. The magnetic powder used is a substance that becomes magnetized when placed in a magnetic field, such as powder of ferromagnetic metals such as iron, cobalt, and nickel, or compounds such as magnetite, γ-Fe ₂ O ₃ , and ferrite, and their compounds. There is an alloy. In particular, in order to exhibit the above-mentioned cleaning effect and good developability, it is preferable that the BET specific surface area by the nitrogen adsorption method be 2 to 20.
m ² /g, particularly 2.5 to 12 m ² /g, and preferably a magnetic powder having a Mohs hardness of 5 to 7. The content of this magnetic powder is preferably 10 to 70% by weight based on the weight of the toner. When producing toner, the constituent materials are thoroughly kneaded using a thermal kneading machine such as a hot roll, kneader, or extruder, and then obtained by mechanical crushing and classification, or in a binder resin solution. method obtained by spray drying after dispersing the material in
Alternatively, various methods can be applied, such as a polymerization toner manufacturing method in which a monomer to constitute the binder resin is mixed with a predetermined material to form an emulsified suspension and then polymerized to obtain a toner. When using the toner of the present invention, the surface hardness of the photoreceptor is 8 g or more, preferably in the range of 10 to 100 g, as measured by the method shown below. If the hardness is low, the photoreceptor is easily scratched, and the scratches may cause latent image disturbances in high humidity.
Toner that is not cleaned may appear.
Furthermore, if the hardness is too large, it becomes impossible to remove the low-resistance substance formed on the surface of the photosensitive plate, resulting in disturbance of the latent image at high humidity. The above hardness is measured as follows. As an example, we will discuss the case of measuring an OPC photoreceptor. For example, fix the OPC photoreceptor to the sample stage of a HEIDON14 surface property measuring machine (manufactured by Shinto Kagaku),
A vertical load xg is applied to the OPC photoreceptor through a diamond needle (conical, with a cone angle of 90°, but the tip is semispherical with a diameter of 0.01mm), and the sample stage is moved 50mm/ Move at the speed of min,
Damage the surface of the OPC photoreceptor. The width of this wound,
For example, it is measured using a microscope attached to a microhardness meter MVK-F (manufactured by Akashi Seisakusho). The above operation is performed with the load xg being set to 10g, 15g, etc.
20g, 25g, 30g, 35g, 40g, etc. are repeated, and from the relationship of linear regression between the scratch width and load, the load that causes a scratch of 50μ is calculated and taken as the hardness of the OPC photoreceptor. If the OPC photoreceptor is a drum, it is necessary to set the OPC photoreceptor on the sample so that scratches are made in the axial direction of the drum. The developer of the present invention can be applied to various development methods. For example, magnetic brush development method, cascade development method, method using conductive magnetic toner described in U.S. Pat. No. 3,909,258, JP-A-53-
Method using high-resistance magnetic toner described in JP-A-31136, JP-A-54-42141, JP-A-55-18656
There are methods such as those described in Japanese Patent Application Publication No. 54-43027, a fur brush development method, a powder cloud method, an impression development method, and the like. When using the toner of the present invention, a blade cleaning method, a fur brush cleaning method, a magnetic brush cleaning method, etc. are used as cleaning methods, but in the present invention, an excellent combination of the toner of the present invention and the photoreceptor is Considering this, the blade cleaning method is preferred. Further, immediately before the cleaning process, a static elimination process or the like may be provided as necessary to facilitate toner cleaning. An example of the cleaning device is shown in FIGS. 1 and 2 of the accompanying drawings. In the drawings, reference numeral 1 indicates a photoreceptor, and this photoreceptor is designed to be rotated in the direction indicated by an arrow in the drawing. During operation of the apparatus, an electrostatic latent image is formed on the photoreceptor 1 by a well-known method, the latent image is visualized by using toner, and this visible image is transferred to a transfer material. A cleaning device 7 is provided to remove toner 2 remaining on the photoreceptor 1 after transfer. The cleaning device shown in FIGS. 1 and 2 includes a cleaning member 8 that is in contact with the surface of the photoreceptor so as to scrape off the toner 2 on the photoreceptor 1, and a cleaning member 8 that removes the toner 2 from the photoreceptor 1. A collecting member 9 for collecting toner is provided. In general, the collecting member 9 is arranged so as to come into contact with the surface of the photoreceptor, and prevents the toner rubbed off by the cleaning member 8 from scattering outside the cleaning device. Cleaning member 8 is JIS like urethane rubber.
-A An elastic rubber blade having a hardness of 60° to 80° is preferable, and can be brought into contact with the photoreceptor 1 at different angles as shown in FIGS. 1 and 2. In this case, the contact pressure is 5 to 20 as shown in Figure 1.
A linear pressure of g/cm is preferable, and in the case shown in Figure 2,
A linear pressure of 30-40 g/cm is preferred. The basic configuration and features of the present invention have been described above, and the present invention will be specifically described below based on Examples. However, this does not in any way limit the embodiments of the present invention. Parts in the examples are parts by weight. Example 1 Styrene-butyl methacrylate-dimethylaminoethyl methacrylate (weight ratio 7:2.5:
0.5) 100 parts by weight of copolymer, BET specific surface area 5m ² /
40 parts by weight of magnetite having a Mohs hardness of 5.5 g and 3 parts by weight of polypropylene having a weight average molecular weight of 15,000 and a boiling point n-hexane extractable content of 20% by weight were mixed and melt-kneaded at 160°C in a roll mill.
After cooling, it was coarsely pulverized in a hammer mill, and then finely pulverized in a jet pulverizer. Next, the mixture was classified using an air classifier to obtain black fine powder having a volume average particle size of approximately 13 μm as a black magnetic toner. The coefficient of dynamic friction of this toner was 0.28. On the other hand, methyl methacrylate-styrene (weight ratio 9:
1) Laminated type with charge transport layer made of copolymer
An OPC photoreceptor was fabricated on a conductive cylinder to obtain a photoreceptor drum. The hardness of this photoreceptor was 21 g. The obtained photosensitive drum and magnetic toner are transferred to a commercially available PC.
-10 (manufactured by Canon Inc.). At this time, the toner remaining on the drum after transfer was cleaned using a device as shown in FIG. At this time, the blade was made of urethane rubber with a JIS-A hardness of 65°, and was brought into contact with the photosensitive drum at a linear pressure of 15 g/cm. A running test of 10,000 sheets was conducted under normal conditions, and good images with stable image density and no image disturbance were obtained. Furthermore, when the photoreceptor was taken out and observed after the running test, there was virtually no damage or filming, and the toner that would have remained after the transfer had been sufficiently cleaned and removed. Furthermore, similar experiments were carried out at 30℃ and 90%RH for 15 days.
Similar good results were obtained when the test was carried out in an environment of ℃10%RH. Example 2 100 parts by weight of fine silica powder (specific surface area approximately 130 m ² /g) synthesized by a dry process was stirred with 12 parts by weight of silicone oil having an amine in the side chain (viscosity at 25°C: 70 cps, amine equivalent: 830). spray,
The temperature was maintained at approximately 250°C for 60 minutes.
The amount of triboelectric charge of the generated treated silica is +130μc/
It was g. The hardness of this silica is 6.0 on the Mohs scale.
It was hot. To 100 parts by weight of the black fine powder obtained in Example 1, 0.4 parts by weight of the above-mentioned fine silica powder treated with silicone oil having an amine in the side chain was added to prepare a toner. The coefficient of dynamic friction of this toner was 0.30. When a copying experiment was carried out in the same manner as in Example 1, clear images were obtained. Furthermore, when a running test of 10,000 sheets was conducted, good images with stable image density and no image disturbance were obtained. Similar experiments were conducted at 30°C, 90% RH, and 15°C, 10% RH, and similarly good results were obtained. After the test, the photosensitive plate was in a clean condition with no damage, almost like a new one. Example 3 The toner formulation of Example 1 was changed, using styrene-butyl methacrylate copolymer instead of styrene-butyl methacrylate-dimethylaminoethyl methacrylate copolymer, adding 3 parts by weight of nigrosine, and adding 3 parts by weight of nigrosine instead of magnetite. Add 5 parts by weight of carbon black to
A black toner was obtained by adding 2 parts by weight of polypropylene having a boiling point of 12% with n-hexane extractable content of 12%.
The coefficient of dynamic friction of this toner was measured to be 0.39. A developer was prepared by mixing 10 parts by weight of this toner and 90 parts by weight of iron powder (product name: ETV250-400 manufactured by Nippon Tetsuko Powder Co., Ltd.) and applied to a commercially available two-component magnetic brush development method copier. When copying was carried out in the same manner as in Example 1 except that the contact angle of the blade was changed and the linear pressure was set to 35 g/cm as shown in FIG. 2, a clear image was obtained. Furthermore, when a running test of 10,000 sheets was conducted, good images with stable image density and no image disturbance were obtained. Similar experiments were conducted at 30°C, 90% RH, and 15°C, 10% RH, and similarly good results were obtained. After the test, the drum was clean and free of dirt, almost like a new drum. Example 4 The same procedure as in Example 1 was carried out except that a styrene-acrylonitrile copolymer having a Tg of 80°C or higher was used instead of the methyl methacrylate-styrene copolymer in the photoreceptor in Example 1. Good results were obtained. The hardness of this photoreceptor is 15
It was hot at g. Example 5 Instead of the polypropylene used in Example 1,
Weight average molecular weight 48000, boiling point n-hexane extractable
Good results were obtained in the same manner as in Example 1 except that 40% by weight of a thermally modified ethylene-propylene copolymer was used. The coefficient of dynamic friction of this toner was 0.20. Example 6 The same procedure as in Example 2 was carried out except that 7 parts by weight of the polypropylene used in Example 1 was added, and good results were obtained. The coefficient of dynamic friction of this toner was 0.45. Example 7 A photoreceptor using polymethyl methacrylate was used instead of the methyl methacrylate-styrene copolymer of Example 1, and the same procedure as in Example 1 was carried out, and good results were obtained under each different environment. I got it. The hardness of this photoreceptor was 38 g. Example 8 Instead of the polypropylene used in Example 1,
Weight average molecular weight 7200 Boiling point n-hexane extractable content 38%
The same procedure as in Example 1 was performed except that polypropylene was used, and good results were obtained. The coefficient of dynamic friction of this toner was 0.21. Comparative Example 1 A toner was prepared in the same manner as in Example 1 without adding the polypropylene used in Example 1. The coefficient of dynamic friction of the toner was 0.12. When running tests were conducted under high temperature and high humidity conditions, significant image distortion occurred. Comparative Example 2 Weight average molecular weight 2800, boiling point n-hexane extract
Example 2 was carried out as in Example 2 except that 60% polyethylene was used. When running tests were conducted under high temperature and high humidity conditions, significant image distortion occurred. The coefficient of dynamic friction of this toner was 0.14. Comparative Example 3 An experiment was carried out in the same manner as in Example 2, except that 8 parts by weight of polypropylene having a weight average molecular weight of 45,000 and a boiling point of 3.0% n-hexane extract was used. The coefficient of kinetic friction of the toner was 0.67. During a running test under high temperature and high humidity, many scratches occurred on the photoreceptor, causing image disturbances.

[Brief explanation of drawings]

In the accompanying drawings, FIGS. 1 and 2 are schematic partial sectional views for explaining an example of a cleaning device used in the present invention. 1... Photoreceptor, 2... Toner, 8... Cleaning member, 9... Collection member.

Claims (1)

[Claims] 1. The weight average molecular weight is 3000 to 80000, and
1 to 60% by weight of polyalkylene containing boiling point n-hexane extractables per 100 parts by weight of the resin component.
Contains 10 parts by weight, and the coefficient of dynamic friction of the toner is 0.20~
A toner for developing an electrostatic image, characterized in that the electrostatic charge is 0.50. 2. The toner for developing an electrostatic image according to claim 1, which is a toner for developing an electrostatic image formed on a laminated OPC photoreceptor. 3 Form an electrostatic charge image on a laminated OPC photoreceptor, and convert the formed electrostatic charge image into a material with a weight average molecular weight of 3000.
~80000 and a boiling point n- of 5-60% by weight
Polyalkylene containing hexane extract is the resin component
1 to 10 parts by weight per 100 parts by weight, and a toner for developing an electrostatic charge image having a coefficient of dynamic friction of 0.20 to 0.50 is visualized to form a visible image, and the formed visible image is transferred, An image forming method characterized by cleaning the surface of a laminated OPC photoreceptor with a blade after transfer.