JP3486535B2 - Image forming method - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an image forming method having a step of developing an electrostatic charge image formed by an electrophotographic method, an electrostatic recording method or a magnetic recording method with a toner.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, US Pat. No. 2,297,691 and JP-B-42-23910 are known.
A number of methods are known as described in JP-B No. 43-24748 and Japanese Patent Publication No. 43-24748. Generally, a photoconductive substance is used to form an electric latent image ( Electrostatic latent image), then develop the latent image with toner, transfer the toner image to a transfer material such as paper, if necessary, and then heat, pressure, heat pressurize, or use solvent vapor. The toner is fixed to obtain a copy, and the toner remaining on the photoconductor without being transferred is cleaned by various methods, and the above steps are repeated.

In recent years, such a copying apparatus has been strictly pursued to be smaller, lighter, faster and more highly reliable, reflecting the changing market needs such as compounding and personalization. As a result, the performance required for the toner is also becoming more sophisticated.

On the other hand, the toner needs to have a positive or negative charge depending on the polarity of the electrostatic latent image to be developed, and for this reason, it is generally known to add a dye, a pigment or a charge control agent. Has been. Today, negative triboelectric charge control agents known in the art include metal complex salts of monoazo dyes, hydroxycarboxylic acids, dicarboxylic acids,
A metal complex salt such as an aromatic diol, a resin containing an acid component, and the like are known. As positive triboelectric chargeability, nigrosine dye,
Known are azine dyes, triphenylmethane dyes and pigments, polymers having quaternary ammonium salts in their side chains, and the like.

However, most of these charge control agents are colored and cannot be used for color toners. Most of the colorless, white, or light color toners applicable to color toner cannot be used in terms of performance.
They have drawbacks such that the uniformity of highlights cannot be obtained and the image density varies greatly in the durability test.

In addition to the above, some charge control agents have the following drawbacks. It is difficult to balance the image density and fog, it is difficult to obtain a sufficient image density in a high humidity environment, the dispersibility in a resin is poor, the storage stability and the fixability are adversely affected.

Conventionally, several proposals have been made for the condensate of phenol and aldehyde, including JP-A-2-201378. However, what is proposed in these publications is the addition of a single unit of condensate.

Further, a cyclic condensate having a single unit number, which has been conventionally added to a toner, has a high melting point and a low solubility in an organic solvent. Therefore, while a high charge amount can be obtained, it cannot be said that it is easy to disperse it in the toner. In particular, when a low-viscosity resin for color toner is used, the dispersion tends to be insufficient and the toner scattering may be deteriorated. In addition, with a single unit, it was not easy to adjust the charging property. For example, when trying to obtain a high charge amount,
When the charging speed is lowered or, on the contrary, an attempt is made to improve the charging speed, the charge amount tends to be lowered.

However, in these conventional negative charge control agents,
Even if a sufficient charge amount is not given to the toner, or even if a sufficient charge amount is given, the toner is influenced by other toner constituent materials and excessive toner triboelectric charging or non-uniform charging causes the occurrence of blotches. This tends to cause an increase in toner cohesiveness, and also tends to cause a decrease in image density and deterioration of developing characteristics such as fog. In addition, there is a problem of sleeve contamination that occurs when the charge control agent is missing from the toner and adheres to the surface of the sleeve, which is the developer carrying member.

On the other hand, when the toner is brought into contact with the sleeve, which is the developer carrying member, and is triboelectrically charged, there is a problem of how long-term stable, efficient and proper charge application can be sustained.

As a sleeve in an image forming apparatus using electrophotography, for example, a metal, an alloy thereof, or a compound thereof is molded into a cylindrical shape, and the surface thereof is subjected to electrolysis, blasting, sanding, etc. to have a predetermined surface roughness. The one treated to is used. As a general sleeve base material, stainless steel, aluminum and nickel proposed in JP-A-57-66455 are widely used.

However, when the toner is charged by using these sleeves, it is difficult to adjust the toner charge amount. For example, when stainless steel is used as the sleeve base material, the charging power is strong. The toner existing in the vicinity of the surface of the sleeve has a very high electric charge, and is strongly attracted to the surface of the sleeve by the mirror image force to form a stationary layer. As a result, the chances of friction of the toner with the sleeve are reduced, and proper charging is hindered. As a result, blotches, image density reduction, and sleeve ghost are likely to occur due to non-uniform charging or excessive charging of toner, and naturally the developing characteristics also deteriorate. "Sleeve ghost" means that when a large amount of toner on the sleeve is consumed due to solid development, etc., the toner in the immovable layer is also consumed, and charging is properly performed again, and the density of the toner consumed portion increases. Is a phenomenon.

When aluminum is used as the sleeve base material, the toner has a high charge imparting ability, but due to the softness of the material, the durability is poor and image deterioration due to surface abrasion is likely to occur. Therefore, in order to have abrasion resistance, there is also a technique of coating or plating a metal on the surface of the aluminum base, but the durability is improved by improving the hardness of the sleeve surface, but compared to stainless steel etc.
Many of them have a small charge imparting ability to the toner, which is apt to cause poor charging of the toner.

[0014]

SUMMARY OF THE INVENTION It is an object of the present invention to provide an image forming method which solves the above problems. That is, the object of the present invention is to obtain a uniform toner coat layer without ghosts and blotches on the developer carrying member, and to obtain stable high image density and low fog with high durability, that is, good long-term stability. An object of the present invention is to provide an image forming method capable of obtaining excellent image characteristics.

[0015]

The above object can be achieved by the following constitutions.

A negatively chargeable toner containing at least a binder resin and a charge control agent is conveyed by a developer carrier having a resin layer formed on a metal substrate, and a static latent image formed on the electrostatic latent image carrier is conveyed. In an image forming method of forming a toner image by transferring a negatively chargeable toner from a developer carrying member to develop an electrostatic latent image, the charge control agent is a phenol derivative which is a condensation product of phenol or its derivative with an aldehyde. A compound having at least 2 condensates with different numbers of units
Condensate containing 4 or more units and containing 4 to 8 units
And an amount of one condensate is 60% or less, and the condensate is a chain condensate, a cyclic condensate, or a mixture thereof. Here, "the number of units" means counting one phenol unit, and the number of phenol units is the number of units.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION The present inventor uses a phenol derivative, which is a condensate of phenol or its derivative and an aldehyde, to obtain good developability without impairing the charging characteristics and powder characteristics as a negatively charging toner. I found that can be realized. Further, by using a developing sleeve formed by forming a resin layer on a metal substrate as a developing sleeve for frictionally charging the toner, excellent charging characteristics which have never been obtained can be obtained, and proper charging can be stably performed for a long time. It has been revealed that it is possible to maintain the excellent development characteristics.

The reason why the effect of the present invention is realized will be described below.

The calixarene conventionally proposed as a charge control agent is a cyclic substance, and the number of units has a single distribution. On the other hand, the present invention contains two or more condensates having different unit numbers.

The first effect of this is that the attenuation characteristic of charging becomes preferable. It is considered that due to the presence of condensates of various sizes, small molecules can enter between large molecules, resulting in a change in electron conduction between molecules. "Charging attenuation characteristics are preferable" means
Specifically, it means that the charge is maintained when it is left standing and that the charge is leaked so as not to have an excessive charge at the time of durability.

It has also been found that the toner after development behaves as a unit by containing two or more kinds. Two
By including at least one kind of condensate, the transferability is improved, and the transfer failure caused by the unevenness of the paper during transfer is less likely to occur. Further, also in the fixing step, fixing scattering is reduced. This also seems to be related to the charge decay after development.

The second effect of containing two or more kinds is that the yield at the time of synthesis is improved and the cost is reduced. This is because condensates having different numbers of units have different conditions of monomers suitable for the reaction. Therefore, it is considered that the residual monomer in the course of the reaction may meet any one of the conditions, and therefore the amount of the monomer that does not contribute to the reaction is reduced.

Further, by containing two or more kinds of condensates having different numbers of units, the crystallinity of the obtained powder is lowered. Therefore, the particles can be formed into fine particles with a weak force, and as a result, the dispersibility in the toner resin is improved. These effects are further improved when the number of units is 3 or more, and it is preferable that a condensate having 4 to 8 units is contained, and more stable charging property is obtained. At this time, the abundance ratio of one condensate is preferably 90% or less, and further 8
It is preferably 0% or less, particularly 70% or less, and further 60% or less, the above-mentioned effect becomes more prominent.

Further, the thing conventionally proposed as the charge control agent is a cyclic material. On the other hand, in the present invention, since a plurality of condensates having different numbers of units are used, it may have a chain structure or a component having a cyclic structure, and an effect can be obtained for each. .

Since the chain-like condensate is excellent in dispersibility, it is slightly inferior in charging property, but uniform charging property is easily obtained. Since the cyclic compound is excellent in chargeability and therefore inferior in dispersibility, a high charge amount can be obtained. These adverse effects are mitigated by using a plurality of condensates having different numbers of units.
Further, when a chain condensate and a cyclic condensate are used at the same time, their respective characteristics are utilized and the rising speed of charging also appears. The condensate having a chain structure is softened at a relatively low temperature like general resins. As a result of mixing this component and the cyclic component, good chargeability can be obtained. This seems to be the following phenomenon. The cyclic component exhibits high chargeability, but this component has cohesive properties and may result in poor dispersion. On the other hand, the chain component does not have a high charge amount, but is easily softened and has good dispersibility. Further, since both of them have basically the same skeleton, they have affinity and are likely to form a fine mixed state. That is, it is considered that the chain component serves as a dispersion aid for the cyclic component, and therefore, uniform and high charging can be achieved.

As described above, when the condensate of the present invention is contained in the toner, it is possible to obtain a toner having a high charge level distribution and a uniform charge amount distribution. Therefore, the high-temperature and high-humidity environment is an environment in which toner scattering easily occurs, but the toner scattering is significantly reduced by containing the condensate of the present invention.

Further, the toner used in the present invention is used on the metal substrate in the frictional charging process with the developer carrier, rather than using the general stainless steel, aluminum or metal plating as the developer carrier material. It was revealed that a developing sleeve having a resin layer formed on the surface of the developing roller has a far superior charge imparting ability.

This is due to the difference in chargeability between the toner and the material of each developer carrier. That is, regarding the toner containing the phenol derivative condensate of the present invention, when the charging ability with the developer carrier material is examined, it is compared with the charge amount generated by contact with stainless steel, aluminum, metal plating, etc. It was found that contact with a metal substrate having a layer (for example, a carbon black-dispersed resin layer) produces a larger amount of charge, but does not result in excessive charge.

The condensate of the present invention can be obtained by heating phenols and aldehydes under alkaline conditions. A chain condensate or a cyclic condensate may be selectively obtained and then mixed. In order to obtain selectively, the addition conditions of the alkali metal may be adjusted, and further the washing and extraction conditions may be adjusted. By adding a plurality of alkali metals, it is possible to increase the types of condensates having different numbers of units. Various kinds of chain-like condensates and mixtures of cyclic condensates can be obtained by adjusting the heating temperature, the time of adding the raw materials, the synthetic conditions such as the synthetic concentration, the solvent, the amount of the alkali metal, and the pH. In addition, examples of the solvent that can be used for washing and extraction include acetone, methyl ethyl ketone, alcohol, ether, hexane, dioxane, toluene, chloroform, tetrahydrofuran, dimethyl sulfoxide, and the like.

The end of the chain condensate of the present invention is a hydrogen atom,
Alkyl groups, alkyl groups including hydroxy groups are preferred,
Hydrogen and alkyl groups, which are advantageous in the amount of charge in a high humidity environment, are preferred. For example, in the general formula (II), one is condensed with phenol and one is hydrogen or a hydroxy group, and in the general formula (I), one is condensed with an aldehyde and one is condensed with hydrogen, an alkyl group or a hydroxyalkyl group. Becomes

The abundance ratio of the chain condensate to the cyclic condensate in the condensate of the present invention is preferably 1:20 to 30: 1. More preferably, it is 1:10 to 20: 1. If the amount of chain-like substances is less than 1:20, the formulation that exhibits the effect of improving dispersion is limited, and if it is not more than 1:10, the effect with a soft resin such as color toner becomes small. In addition, when the chain-like substance is contained in the amount of 1:20 or more, the charging suitable for the development is quickly reached, and the toner supplied to the developing device is quickly replaced and consumed. 1: 1
By including 0 or more, replacement is particularly fast in a low humidity environment. As a result, deteriorated toner is less likely to be generated when the toner is durable, and the image quality is improved. Further, the generation of toner having an excessive charge (so-called charge-up) is reduced, and the transition of image density is stabilized.

On the other hand, if the number of annular particles is less than 30: 1, the toner prescription is limited when a high charge amount is required. When the number of ring-shaped particles is less than 20: 1, it becomes difficult to apply to magnetic toner having a small particle size.

Here, a unit having one unit is included in the chain condensate.

Further, in the present invention, the condensate preferably contains units represented by the following general formulas (I) and (II).

[0035]

[Chemical 3] [In the formula, i represents 0 or 1, and when i is 0, R ₁ has a hydrogen atom, a halogen atom, an alkyl group, an optionally substituted aryl group, an aralkyl group, or a substituent. Which may have an alicyclic group, a fluoroalkyl group,
A nitro group, an optionally substituted sulfone group, an optionally substituted amino group or a trialkylsilyl group, and when i is 1, R ₁ is an alkyl group or an optionally substituted aryl Group, an aralkyl group, an alicyclic group which may have a substituent, an optionally substituted amino group or a trialkylsilyl group, and R ₂ represents a hydrogen atom, an alkyl group, a phenyl group, an aralkyl group, -C
OR ₅ (R ₅ represents a hydrogen atom or an alkyl group) or −
(CH ₂ ) _m COOR ₆ (R ₆ represents a hydrogen atom or an alkyl group, m represents an integer of 1 to 3), R ₃ represents a hydrogen atom, an alkyl group, a halogen atom, a carboxyl group, a hydroxy group, Cyano group, nitro group, halogenated alkyl group, trialkylsilyl group, ester group having 1 to 8 carbon atoms, optionally substituted amino group, acyl group, optionally substituted sulfone group, 1 to 1 carbon atoms 8 represents an ether group, and R ₄ represents a hydrogen atom, an alkyl group or an aryl group. ]

Further, a condensate which is a condensate containing a unit represented by the following general formula (III) is also used.

[0037]

[Chemical 4] [R ₁ and R ₂ may be the same or different and may be a hydrogen atom, a halogen atom, an alkyl group, an aryl group which may have a substituent, an aralkyl group or a substituent which may have a substituent. Represents a good alicyclic group, fluoroalkyl group, nitro group, optionally substituted sulfone group, optionally substituted amino group or trialkylsilyl group,
R ₃ and R ₄ may be the same or different and each is a hydrogen atom, an alkyl group, a halogen atom, a carboxyl group, a hydroxy group, a cyano group, a nitro group, a halogenated alkyl group, a trialkylsilyl group, or a carbon number. 1-8 ester groups, which may be substituted an amino group, an acyl group, an sulfonic group which may be substituted, represents an ether group having 1 to 8 carbon _{atoms, X 1, X 2, X} 3, X 4 Represents a linking position and may form a ring by linking with the unit represented by (I) or the unit represented by (III) through the unit represented by the general formula (II), and is a terminal. In the case, it represents a hydrogen atom, an alkyl group or a hydroxyalkyl group. ]

The structure of the condensate of the present invention is applicable as long as the substituent Rn in the general formulas (I) to (III) does not inhibit the condensation reaction.

When the substituent R ₁ in the general formula (I) is an alkyl group, an aryl group which may have a substituent, an aralkyl group or an alicyclic group, the charge amount is high and the charge rises. Tends to be good. Among them, a phenyl group which may have a substituent, a cumyl group, a normal alkyl group and a cycloalkyl group are preferable, and more preferably at least one phenyl group or a carbon number of 3
Those having the following alkyl groups and cycloalkyl groups having 8 or less carbon atoms are preferable because the charge maintainability is improved. Further, by having a phenyl group, a methyl group, an ethyl group, a propyl group, a cyclopentyl group, and a cyclohexyl group, an appropriate amount of charge can be maintained, and transfer and fixing can be easily controlled. This reduces image disturbance during transfer and fixing.

Further, although there are substituents which adversely affect the toner fixing performance, a methyl group, a phenyl group and a cyclohexyl group are preferable in that they do not have an adverse effect.

Further, it is preferable to introduce a phenyl group or a methyl group into the raw material phenol by using p-phenylphenol or p-cresol from the viewpoint of ease of synthesis.

The substituent R ₂ in the general formula (I) is preferably a hydrogen atom, but is preferably an alkyl group or an aralkyl group.

The substituent R ₃ in the general formula (I) is preferably a hydrogen atom, but other than that, an alkyl group, a halogen atom and a nitro group are effective in improving the charge amount.

In the substituent R ₄ in the general formula (I), a hydrogen atom is preferable, but in other cases, a methyl group does not hinder the condensation reaction and it is preferable that impurities harmful to the toner performance are not contained.

Condensates having two or more units having different substituents are also preferable. By using two or more kinds, the crystallinity of the obtained powder is disrupted, the dispersibility in the toner, and the rising of charging can be adjusted. As the combination, for example, a combination of a phenyl group and a cyclohexyl group, a phenyl group and a methyl group, and a methyl group and a cyclohexyl group are preferable.

As the method of incorporating the compound of the present invention into the toner, there are a method of adding it inside the toner and a method of adding it externally. When added internally, the addition amount is preferably 0.1 to 10 parts by mass, and more preferably 0.5 to 5 parts by mass with respect to 100 parts by mass of the binder resin. Also,
When added externally, 0.01 to 5 parts by mass is preferable.

The compounds of the present invention can also be used in combination with known charge control agents as described in the prior art.

The specific structure of the condensate of the present invention is illustrated below.

The abundance ratio is obtained by measuring the molecular weight distribution using FD-MS (electrolytic desorption mass spectrometry) and determining the intensity ratio of the m / z peak as the abundance ratio. Calculate the molecular weight of each unit,
The molecular weight of the condensate composed of the unit is calculated to obtain the unit structure.

Condensate (1): Mixture A of a condensate composed of at least one unit selected from the following four types of units and formaldehyde as a starting material (feeding ratio is A: aldehyde = 1: 2) between units Are bound with methylene

[0051]

[Chemical 5] Example of structural formula

[0052]

[Chemical 6]

[0053]

[Table 1]

Condensate (2): Mixture A of a condensate composed of at least one unit selected from the same four kinds of units as in the condensate (1) and formaldehyde as a starting material (a charging ratio is A: aldehyde = 1: 2) Methylene bonds between units

[0055]

[Chemical 7]

[0056]

[Table 2]

Condensate (3): A mixture of a condensate composed of at least one unit selected from the same four kinds of units as in the condensate (1) and formaldehyde as a starting material (a charging ratio is A: aldehyde = 1: 2) Methylene bonds between units

[0058]

[Table 3]

Condensate (4): a mixture A of a condensate composed of at least one unit selected from the following two units and formaldehyde as a starting material (feeding ratio is A: aldehyde = 1: 2) between units Are bound with methylene

[0060]

[Chemical 8] Example of structural formula

[0061]

[Chemical 9]

[0062]

[Table 4]

Condensate (5): Mixture A of a condensate composed of at least one unit selected from the same two units as in the condensate (4) and formaldehyde as a starting material (feeding ratio is A: aldehyde = 1: 2) An example of a structural formula in which methylene is used between units

[0064]

[Chemical 10]

[0065]

[Table 5]

Condensate (6): Mixture A of a condensate composed of at least one unit selected from two units similar to the condensate (4) and formaldehyde as starting materials (feeding ratio is A: aldehyde = 1: 2) Methylene bonds between units

[0067]

[Table 6]

Condensate (7): Mixture A of a condensate composed of at least one unit selected from the following three types of units and formaldehyde as a starting material (feeding ratio is A: aldehyde = 1: 2) between units Are bound with methylene

[0069]

[Chemical 11] Example of structural formula

[0070]

[Chemical 12]

[0071]

[Table 7]

Condensate (8): Mixture A of a condensate composed of at least one unit selected from the same three types of units as in the condensate (7) and formaldehyde as a starting material (feeding ratio is A: aldehyde = 1: 2) An example of a structural formula in which methylene is used between units

[0073]

[Chemical 13]

[0074]

[Table 8]

Condensate (9): A mixture of a condensate composed of at least one unit selected from the same three kinds of units as in the condensate (7) and formaldehyde as a starting material (a charging ratio is A: aldehyde = 1: 2) Methylene bonds between units

[0076]

[Table 9]

Condensate (10): Mixtures A and E of condensate composed of at least one unit selected from the following 6 types of units and formaldehyde as starting materials (charge ratio: A:
E: Aldehyde = 1: 1: 4) Methylene bonds between units

[0078]

[Chemical 14]

[0079]

[Table 10]

Condensate (11): Mixtures A and E of condensate composed of at least one unit selected from the following seven types of units and formaldehyde as starting materials (charge ratio: A:
E: Aldehyde = 1: 1: 4) Methylene bonds between units

[0081]

[Chemical 15]

[0082]

[Table 11]

Condensate (12): Mixtures A and E of condensate composed of at least one unit selected from the following five types of units and formaldehyde as starting materials (charge ratio: A:
E: Aldehyde = 1: 1: 4) Methylene bonds between units

[0084]

[Chemical 16]

[0085]

[Table 12]

Condensate (13): Mixtures A and C of condensate composed of at least one unit selected from the following four types of units and formaldehyde as starting materials (charge ratio: A:
C: Aldehyde = 1: 1: 4) Units are linked with methylene

[0087]

[Chemical 17]

[0088]

[Table 13]

Condensate (14): Mixtures A and B of condensate composed of at least one unit selected from the following two types of units and formaldehyde as starting materials (charge ratio: A:
B: Aldehyde = 1: 1: 4) Methylene bonds between units

[0090]

[Chemical 18]

[0091]

[Table 14]

Condensate (15): A mixture of a condensate A composed of at least one unit selected from the units A, B and C, and formaldehyde and acetaldehyde as starting materials (the charge ratio is A: formaldehyde: acetaldehyde = 1. : 1: 1.5)

[0093]

[Chemical 19]

[0094]

[Table 15]

Condensate (16): a mixture A (X is hydrogen) of a condensate composed of at least one unit selected from the following four types of units and formaldehyde as a starting material (charge ratio: A: aldehyde = 1) : 2)

[0096]

[Chemical 20]

[0097]

[Table 16]

Condensate (17): a mixture A of a condensate composed of at least one unit selected from the following two types of units and formaldehyde as a starting material (a charging ratio is A: aldehyde = 1: 2) between units For the alkylation of the hydroxyl group bound with methylene, butyl iodide is reacted after the condensation reaction.

[0099]

[Chemical 21]

[0100]

[Table 17]

Condensate (18): a mixture A of a condensate composed of at least one unit selected from the following units A, B, C and D and at least one unit selected from units E and F: Starting materials are C, formaldehyde, and acetaldehyde (the charge ratio is A: C: formaldehyde: acetaldehyde = 1: 1: 2: 2). Units are linked by methylene.

[0102]

[Chemical formula 22]

[0103]

[Table 18]

Condensate (19): a mixture of condensates A, C, E and formaldehyde composed of at least one unit selected from the following 6 types of units as starting materials (charge ratio: A: C: E: Aldehyde = 1: 1: 1: 6) Methylene bonds between units

[0105]

[Chemical formula 23]

[0106]

[Table 19]

Condensate (20): Mixtures A and C of condensate composed of at least one unit selected from the following 6 types of units and formaldehyde as starting materials (charge ratio: A:
C: Aldehyde = 1: 1: 4) Units are linked with methylene

[0108]

[Chemical formula 24]

[0109]

[Table 20]

As the binder resin used in the toner of the present invention, the following polymers can be used.

For example, homopolymers of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene and the like, and substitution products thereof; styrene-p-chlorostyrene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene. Copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer -Based copolymer; polyvinyl chloride, phenol resin, natural modified phenol resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin , Xylene resin, polyvinyl butyral, terpene resin, coumarone indene resin, petroleum resin and the like can be used. A preferable binder resin is a styrene copolymer or a polyester resin.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, acrylic acid-
2-carboxylic acid having a double bond such as 2-ethylhexyl, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, and acrylamide;
For example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like; and substituted compounds thereof; for example, vinyl chloride,
Vinyl esters such as vinyl acetate, vinyl benzoate, etc .; Ethylenic olefins such as ethylene, propylene, butylene, etc .; Vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, etc .; eg vinyl methyl ether, vinyl Vinyl ethers such as ethyl ether, vinyl isobutyl ether, etc .;

The styrene polymer or styrene copolymer may be crosslinked or may be a mixed resin.

As the crosslinking agent for the binder resin, a compound mainly having two or more polymerizable double bonds may be used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; Divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone; and 3
A compound having at least one vinyl group; is used alone or as a mixture.

The method for synthesizing the styrene-based copolymer may be any of bulk polymerization, solution polymerization, suspension polymerization and emulsion polymerization.

In the bulk polymerization method, it is possible to obtain a low molecular weight polymer by polymerizing at a high temperature to accelerate the termination reaction rate, but it is difficult to control the reaction.
In the solution polymerization method, a low molecular weight polymer can be easily obtained under mild conditions by utilizing the difference in radical chain transfer depending on the solvent, and by adjusting the amount of the initiator and the reaction temperature.
It is preferable to obtain a low molecular weight polymer having a maximum value of the molecular weight in the molecular weight range of 5,000 to 100,000 in the C chromatogram.

As the solvent used in the solution polymerization, xylene, toluene, cumene, cellosolve acetate, isopropyl alcohol, benzene and the like can be used. In the case of a styrene monomer mixture, xylene, toluene or cumene are preferred. It is appropriately selected depending on the polymer to be polymerized.

The reaction temperature varies depending on the solvent used, the initiator and the polymer to be polymerized, but is 70 ° C to 23 ° C.
It is better to do it at 0 ° C. Solvent 100 in solution polymerization
It is preferable to perform 30 to 400 parts by mass of the monomer with respect to parts by mass.

Further, it is also preferable to mix another polymer in the solution at the end of the polymerization, and several polymers can be mixed well.

Further, as a polymerization method for obtaining a high molecular weight polymer or a crosslinked polymer having a maximum value of the molecular weight in the region of the molecular weight of 100,000 or more in the GPC chromatogram
An emulsion polymerization method and a suspension polymerization method are preferable.

Among them, the emulsion polymerization method is a method in which a monomer (monomer) almost insoluble in water is dispersed as small particles in an aqueous phase with an emulsifier, and polymerization is carried out using a water-soluble polymerization initiator. . In this method, the heat of reaction can be easily adjusted, and the termination reaction rate is low because the phase in which the polymerization is performed (oil phase consisting of polymer and monomer) and the aqueous phase are different, resulting in a high polymerization rate. A high degree of polymerization can be obtained.
Further, the reason is that the polymerization process is relatively simple, and that the polymerization product is fine particles, so that it is easy to mix with a colorant, a charge control agent and other additives in the production of toner. Therefore, it is advantageous as a method for producing a binder resin for toner as compared with other methods.

However, the resulting polymer is apt to become impure due to the added emulsifier, and suspension polymerization is a simple method because an operation such as salting out is required to take out the polymer.

In the suspension polymerization, 100 parts by mass or less of the monomer (preferably 1 part by mass) is used with respect to 100 parts by mass of the aqueous solvent.
0 to 90 parts by mass) is preferable. As the dispersant that can be used, polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate, etc. are used, and there is an appropriate amount such as the amount of monomers in the aqueous solvent, but generally 0.05 to 1 per 100 parts by weight of the aqueous solvent. Used in parts by weight. The polymerization temperature is suitably 50 to 95 ° C., but it should be appropriately selected depending on the initiator used and the target polymer. As the initiator, any initiator that is insoluble or hardly soluble in water can be used.

Examples of the initiator used in these polymerization methods are t-butylperoxy-2-ethylhexanoate, cumin perpivalate, t-butylperoxylaurate, benzoyl peroxide, lauroyl peroxide and octa. Noyl peroxide, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,2′-azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile) 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), 1,1-bis (t-butylperoxy) 3 , 3,5-Trimethylcyclohexane, 1,1-bis (t-butylperoxy) cyclohexane, 1,4-bis (T-Butylperoxycarbonyl) cyclohexane, 2,2-bis (t-butylperoxy) octane, n-butyl 4,4-bis (t-
Butylperoxy) valerate, 2,2-bis (t-butylperoxy) butane, 1,3-bis (t-butylperoxy-isopropyl) benzene, 2,5-dimethyl-2,5-di (t-) Butyl peroxy) hexane, 2,
5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (benzoylperoxy) hexane, di-t-butyldiperoxyisophthalate, 2,2 -Bis (4,4-di-t-butylperoxycyclohexyl) propane, di-t-butylperoxy α-methylsuccinate, di-t-butylperoxydimethylglutarate, di-t-butylperoxyhexa Hydroterephthalate, di-t-butylperoxyazelate, 2,5-dimethyl-2,5-di (t-
Butyl peroxy) hexane, diethylene glycol-
Bis (t-butyl peroxycarbonate), di-t-
Butyl peroxytrimethyl adipate, tris (t-
Examples thereof include butylperoxy) triazine and vinyltris (t-butylperoxy) silane, which can be used alone or in combination.

The amount used is 0.05 parts by mass or more (preferably 0.1 to 15 parts by mass) with respect to 100 parts by mass of the monomer.

The composition of the polyester resin used in the present invention is as follows.

Examples of the divalent alcohol component include ethylene glycol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, diethylene glycol, triethylene glycol and 1,5-pentanediol. 1,6-hexanediol, neopentyl glycol, 2-ethyl-1,3-
Hexanediol, hydrogenated bisphenol A, bisphenol represented by the formula (A) and derivatives thereof;

[0128]

[Chemical 25]

(Wherein R is an ethylene or propylene group, x and y are each an integer of 0 or more, and
The average value of x + y is 0-10. )

Diols represented by the formula (B);

[0131]

[Chemical formula 26]

(In the formula, R ′ is —CH ₂ CH ₂ — or

[0133]

[Chemical 27] Where x ′ and y ′ are integers greater than or equal to 0, and x ′
The average value of + y 'is 0 to 10. ) Is mentioned.

As the divalent acid component, for example, phthalic acid,
Benzenedicarboxylic acids such as terephthalic acid, isophthalic acid and phthalic anhydride, or their anhydrides, lower alkyl esters; alkyldicarboxylic acids such as succinic acid, adipic acid, sebacic acid, azelaic acid or their anhydrides, lower alkyl esters; n- Alkenyl succinic acids such as dodecenyl succinic acid, n-dodecyl succinic acid or alkyl succinic acids, or their anhydrides, lower alkyl esters; unsaturated dicarboxylic acids such as fumaric acid, maleic acid, citraconic acid, itaconic acid or their anhydrides, lower Examples thereof include dicarboxylic acids such as alkyl ester; and derivatives thereof.

Further, it is preferable to use an alcohol component having a valence of 3 or more and an acid component having a valence of 3 or more, which also serve as a crosslinking component.

Examples of the trihydric or higher polyhydric alcohol component include:
For example, sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol,
1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,
3,5-trihydroxybenzene etc. are mentioned.

Examples of the trivalent or higher polycarboxylic acid component in the present invention include trimellitic acid, pyromellitic acid, 1,2,4-benzenetricarboxylic acid, 1,
2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,
5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,2,7,8-
Octane tetracarboxylic acid, empol trimer acid, and their anhydrides, lower alkyl esters;

[0138]

[Chemical 28]

(Wherein, X is an alkylene or alkenylene group having 1 to 30 carbon atoms having at least one side chain having 1 or more carbon atoms), a tetracarboxylic acid or the like, and an anhydride or lower alkyl ester thereof. And polyvalent carboxylic acids and derivatives thereof.

The alcohol component used in the present invention is 40 to 60 mol%, preferably 45 to 55 mol.
%, 60-40 mol% as an acid component, preferably 5
It is preferably 5 to 45 mol%.

It is also preferable that the trivalent or higher polyvalent component accounts for 1 to 60 mol% of all components.

The polyester resin is also obtained by a generally known polycondensation.

In addition to the above binder resin component, the toner according to the present invention may contain the following compounds in a proportion smaller than the content of the binder resin component. For example, silicone resin, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin,
Examples thereof include phenolic resins and copolymers of two or more kinds of α-olefins.

The glass transition point (Tg) of the binder resin used in the toner of the present invention is preferably 45 to 80 ° C, more preferably 50 to 70 ° C.

In the present invention, the following waxes are preferably contained in order to give the toner releasability. A wax having a melting point of 70 to 165 ° C. and a melt viscosity at 160 ° C. of 1000 mPa · s or less, and specific examples thereof include paraffin wax, microcrystalline wax, Fischer-Tropsch wax, montan wax, ethylene, propylene, butene-1. ,
Linear α-olefins such as pentene-1, hexene-1, heptene-1, octene-1, nonene-1, decene-1 and branched α-olefins having a branched moiety at their ends and their Examples thereof include homopolymers of olefins having different positions of unsaturated groups or copolymers thereof.

Further, a modified wax obtained by forming a block copolymer with a vinyl-based monomer or graft-modifying may be used.

The addition amount of the above wax is preferably 0.5 to 10 parts by mass, and more preferably 1 to 8 parts by mass, relative to 100 parts by mass of the binder resin. Two or more types of wax may be used in combination.

These waxes are used in the production of toner.
It is also possible to add and mix it in the polymer component in advance. In that case, it is preferable to pre-dissolve the wax and the high molecular weight polymer in a solvent when preparing the polymer component, and then mix them with the low molecular weight polymer solution. As a result, phase separation in the microscopic region is alleviated, reaggregation of the high molecular weight component is suppressed, and a good dispersion state with the low molecular weight polymer is also obtained.

The solid concentration of the polymer solution is preferably 5 to 70 parts by mass or less in consideration of dispersion efficiency, deterioration of the resin during stirring, operability, etc., and a preliminary solution of the high molecular polymer and wax. Is preferably 5 to 60 parts by mass and the low molecular weight polymer solution has a solid concentration of 5 to 70 parts by mass or less.

The method of dissolving or dispersing the high molecular weight polymer and the wax is carried out by stirring and mixing. The stirring is preferably carried out batchwise or continuously.

In the method of mixing the low molecular weight polymer solution, it is preferable to add 10 to 1000 parts by mass of the low molecular weight polymer solution to 100 parts by mass of the solid content of the preliminary solution and perform stirring and mixing. In this case, a batch system or a continuous system may be used.

Examples of the organic solvent used when the resin composition solution is mixed include benzene, toluene, xylene, solvent naphtha No. 1, solvent naphtha No. 2, solvent naphtha No. 3, cyclohexane, ethylbenzene, Solvesso 100, Solvesso 150, mineral spirits. Hydrocarbon solvents such as; methanol, ethanol, iso-
Propyl alcohol, n-butyl alcohol, sec-
Alcohol solvents such as butyl alcohol, iso-butyl alcohol, amyl alcohol, cyclohexanol; ketone solvents such as acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone; ester solvents such as ethyl acetate, n-butyl acetate, cellosolve acetate; Examples thereof include ether solvents such as methyl cellosolve, ethyl cellosolve, butyl cellosolve, and methyl carbitol. Among these, aromatic solvents, ketone solvents or ester solvents are preferable. Moreover, these may be mixed and used.

The method of removing the organic solvent is preferably a method of heating the organic solvent solution of the polymer, removing 10 to 80 parts by mass of the organic solvent under normal pressure, and then removing the residual solvent under reduced pressure. At this time, it is preferable to keep the organic solvent solution in the range of 200 ° C. from the boiling point of the organic solvent used.

When the boiling point of the organic solvent is lower than the above, not only the efficiency at the time of distilling off the solvent is poor, but also unnecessary shearing force is applied to the polymer in the organic solvent, and the redispersion of each constituent polymer is promoted. In some cases, phase separation may occur. Further, if the temperature exceeds 200 ° C., the polymer is depolymerized, an oligomer is generated by molecular cleavage, and impurities are mixed into the resin composition, which is not preferable.

The magnetic materials used in the present invention include magnetite, maghemite, and iron oxide of ferrite; metals such as iron, cobalt, and nickel, or these metals and aluminum, cobalt, copper, lead, magnesium, tin, zinc, Antimony, beryllium, bismuth, cadmium,
Alloys of metals such as calcium, manganese, selenium, titanium, tungsten, vanadium and mixtures thereof are used.

The shape of the magnetic material used in the present invention is hexahedron, octahedron, decahedron, dodecahedron, tetradecahedron, or a polyhedron having more than one surface, acicular, scaly, spherical, or irregular shape. The thing etc. are used. Of these, polyhedrons are preferably used. In the case of a polyhedral magnetic body, its shape can physically prevent detachment from the toner particles.

The magnetic substance used in the toner of the present invention is
BET specific surface area by nitrogen gas adsorption method is 1 to 40 m ²
/ G, preferably ² to 30 m ² / g, more preferably 3
~ ²⁰ m ² / g is good. As a measuring method, according to the BET method, a specific surface area measuring device: Autosorb 1 (manufactured by Yuasa Ionics) was used to adsorb nitrogen gas on the sample surface,
The specific surface area is calculated using the BET multipoint method.

The saturation magnetization of the magnetic material is 79
5 to 200 Am ² / in a magnetic field of 5.8 kA / m
kg, preferably in the range of 10 to 150 Am ² / kg is used.

Furthermore, the residual magnetization of the magnetic material is 79
1 to 100 Am ² / in a magnetic field of 5.8 kA / m
kg, preferably 1 to 70 Am ² / kg is used.

The average particle size of the magnetic material is 0.
05-1.0 μm is preferable, and 0.1 is more preferable.
The thickness is 0.6 μm, particularly preferably 0.1 to 0.4 μm.

In the present invention, the amount of the magnetic substance contained in the toner is 10 to 200 parts by mass, preferably 20 to 170 parts by mass, and more preferably 30 to 150 parts by mass based on 100 parts by mass of the binder resin.

In the present invention, the shape of the magnetic material was observed with a transmission electron microscope and a scanning electron microscope.

The magnetic characteristics of the magnetic material are values measured under an external magnetic field of 795.8 kA / m using a "vibrating sample magnetometer VSM-3S-15" (manufactured by Toei Industry Co., Ltd.).

In the toner of the present invention, the charging stability,
To improve developability, fluidity and durability, it is preferable to add silica, alumina and titania fine powder.

[0165] The fine powder used in the present invention has a specific surface area by the BET method by nitrogen adsorption 2.0 m ² / g or more, particularly in the range of 50 to 400 m ² / g give good results. Fine silica powder 0.
It is recommended to use 01 to 8 parts by mass, preferably 0.1 to 5 parts by mass.

Further, the fine powder used in the present invention contains, if necessary, a silicone varnish, various modified silicone varnishes, silicone oils, various modified silicone oils, silane coupling agents, functional compounds for the purpose of hydrophobizing, controlling chargeability, etc. It is also preferable that the treatment is carried out with a treating agent such as a silane compound having a group or other organic silicon compound, or in combination with various treating agents.

If necessary, other external additives may be added to the toner of the present invention.

Examples thereof include resin auxiliary particles, inorganic particles, and the like, which act as a charging aid, a conductivity-imparting agent, a fluidity-imparting agent, an anti-caking agent, a release agent at the time of fixing with a heat roller, a lubricant, an abrasive and the like.

Examples of the lubricant include Teflon powder, zinc stearate powder, polyvinylidene fluoride powder, and the like, of which polyvinylidene fluoride powder is preferable. Examples of the polishing agent include cerium oxide powder, silicon carbide powder, and strontium titanate powder. Among them, strontium titanate powder is preferable. Examples of the fluidity-imparting agent include titanium oxide powder and aluminum oxide powder, and among them, hydrophobic ones are preferable. Examples of the conductivity imparting agent include carbon black powder, zinc oxide powder, antimony oxide powder, tin oxide powder and the like. Furthermore, a small amount of reverse polarity white fine particles and black fine particles can be used as a developing property improver.

Examples of the colorant that can be used in the toner of the present invention include any suitable pigment or dye. As the colorant of the toner, for example, carbon black as a pigment,
Examples include aniline black, acetylene black, naphthol yellow, hansa yellow, rhodamine lake, alizarin lake, red iron oxide, phthalocyanine blue, and indanthrene blue. These are used in an amount necessary and sufficient for maintaining the optical density of the fixed image, and are 0.1 to 20 parts by mass, preferably 0.2 to 10 parts by mass with respect to 100 parts by mass of the resin.
The addition amount of parts by mass is good. Further, a dye is further used for the same purpose. For example, there are azo dyes, anthraquinone dyes, xanthene dyes, methine dyes, and resin 100
0.1 to 20 parts by weight, preferably 0.3
The addition amount of 10 to 10 parts by mass is good.

To prepare the toner of the present invention, a binder resin, a phenol derivative condensate, and, if necessary, a magnetic material, wax, metal salt or metal complex, pigment or dye, other additives, etc. After sufficiently mixing with a mixer such as a mixer or a ball mill, melt kneading using a heat kneader such as a heating roll, kneader, or extruder, cooling and solidifying, pulverizing and classifying, and further adding desired additives as necessary. The toner can be obtained by thoroughly mixing the agents with a mixer such as a Henschel mixer.

Further, in recent years, the toner particle size has been reduced, and even when the volume average particle size is 10 μm or less,
The charging uniformity is promoted, the cohesiveness of the toner is reduced, and the developability such as the improvement of the image density and the fog is improved. In particular, the effect is remarkable with toner having a volume average particle diameter of 6.0 μm or less, and an extremely high-definition image can be obtained. It is preferable that the volume average particle diameter is 2.5 μm or more because a sufficient image density can be obtained. On the other hand, when the toner has a smaller particle size, condensate is more likely to be liberated, but the toner of the present invention has excellent dispersibility, so that good developability is maintained.

The volume average particle diameter of the magnetic toner of the present invention is Coulter Multisizer (manufactured by Coulter), and the electrolyte is ISOTON R-II (1% NaCl aqueous solution,
Coulter Scientific Japan Co., Ltd.). As the measuring method, the electrolytic aqueous solution 100 to
0.1 to 5 m of a surfactant as a dispersant in 150 ml.
1 and 2 to 20 mg of the measurement sample are further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment with an ultrasonic disperser for about 1 to 3 minutes, the volume and the number are measured by the measuring device, and the volume average particle diameter is calculated.

100 when the volume average particle size is 6 μm or more
Particles of 2 to 60 μm are measured using an aperture of μm, particles of 1 to 30 μm are measured using an aperture of 50 μm when the volume average diameter is 6 to 2.5 μm, and when the volume average particle size is less than 2.5 μm. Particles of 0.6-18 μm are measured using a 30 μm aperture.

Next, the structure of the sleeve which is the developer carrying member of the present invention will be described with reference to FIG.

The sleeve which is the developer carrying member of the present invention is
Cylindrical substrate and coating layer (resin layer) covering the surface of the substrate
Have. The resin layer 1 contains a binder resin 4, a conductive substance 2, a filler 3, a solid lubricant 5 and the like in some cases, and is coated on a cylindrical substrate 6. When the conductive material is contained, the resin layer 1 is conductive, so that excessive charging of the toner can be prevented. When the filler 3 is contained, the abrasion of the resin layer 1 due to the toner can be prevented, and the charging property of the filler 3 can also suitably control the charging of the toner. Further, when the solid lubricant 5 is contained, the releasing property between the toner and the sleeve is improved, and as a result, the fusion of the toner on the sleeve can be prevented.

When the resin layer of the developer carrying member according to the present invention contains a conductive substance, the volume resistance of the resin layer is 10 or less.
^{It is 6} Ω · cm or less, preferably 10 ³ Ω · cm or less. When the volume resistance of the resin layer exceeds 10 ⁶ Ω · cm, toner charge-up easily occurs,
This may cause blotches and deterioration of developing characteristics.

The volume resistance of the resin layer is obtained by coating the insulating composition sheet with the constituent composition as a coating material and drying it by a bar coater.
It can be cut into 10 cm × 10 cm and measured with a low resistivity meter, Lorester (manufactured by Mitsubishi Petrochemical Co.).

The surface roughness of the resin layer is preferably in the range of 0.2 to 3.5 μm in terms of JIS center line average roughness (Ra). When Ra is less than 0.2 μm, the charge amount of the toner in the vicinity of the sleeve becomes too high, the toner is attracted onto the sleeve by the mirror image force, and new toner is not given a charge from the sleeve, resulting in insufficient developability. Become. When Ra exceeds 3.5 μm, the toner coat amount on the sleeve is excessively increased, the toner cannot obtain a sufficient charge amount, and the toner is unevenly charged, which causes reduction in image density and uneven density.

Next, each material constituting the conductive resin layer 1 will be described.

In FIG. 1, examples of the conductive material 2 include metal powders such as aluminum, copper, nickel and silver; metal oxides such as antimony oxide, indium oxide and tin oxide; carbon fiber, carbon black and graphite. A carbon allotrope can be mentioned. Among them, carbon black is particularly preferable because it is excellent in electric conductivity and can be filled with a polymer material to give conductivity, or by controlling the addition amount to obtain an arbitrary conductivity to some extent. The number average particle diameter of the carbon black used in the present invention is 1 μm or less, preferably 0.01 μm to 0.
8 μm is preferable. When the number average particle diameter of carbon black exceeds 1 μm, it becomes difficult to control the volume resistance of the resin layer, which is not preferable.

The amount of the conductive material used is the binder resin 1
The amount is preferably 0.1 to 300 parts by mass, more preferably 1 to 100 parts by mass with respect to 00 parts by mass.

Examples of the filler 3 include inorganic compounds such as alumina, asbestos, glass fiber, calcium carbonate, magnesium carbonate, barium carbonate, barium sulfate, silica and calcium silicate; phenol resin, epoxy resin, melamine resin, silicone resin. , PMMA, terpolymers of methacrylate (for example polystyrene / n-butyl methacrylate / silane terpolymer), styrene-butadiene copolymers, polycaprolactam, polyvinyl pyridine, nitrogen-containing compounds such as polyamide; polyvinylidene fluoride, polyvinyl chloride , Polytetrafluoroethylene, polytetrachlorofluoroethylene, perfluoroalkoxylated ethylene, polytetrafluoroalkoxyethylene, fluorinated ethylene propylene-polytetrafluoroethylene Ren copolymer, trifluorochloroethylene - highly halogenated polymers such as vinyl chloride copolymers; Other polycarbonates, polyesters, and the like. Among them, silica and alumina are preferably used because they have hardness of themselves and charge controllability for toner.

The amount of the filler used is 100% by weight of the binder resin.
It is preferably 0.1 to 500 parts by mass, and more preferably 1 to 200 parts by mass with respect to parts by mass.

Examples of the solid lubricant 5 include molybdenum disulfide, silicon nitride, graphite, graphite fluoride, silver-niobium selenide, calcium chloride-graphite, and talc. Of these, graphite is preferably used because it has electrical conductivity as well as lubricity, reduces the toner having an excessively high electric charge, and has a function of giving an effective charge amount for development.

As the amount of the solid lubricant used, the binder resin 1
The amount is preferably 0.1 to 300 parts by mass, more preferably 1 to 150 parts by mass with respect to 00 parts by mass.

As the binder resin 4 in which the conductive substance 2, and in some cases the filler 3 and the solid lubricant 5 are dispersed, a phenol resin, an epoxy resin, a polyamide resin,
Known resins such as polyester resins, polycarbonate resins, polyolefin resins, silicone resins, fluorine resins, styrene resins, and acrylic resins are used. Particularly, a thermosetting or photocurable resin is preferable.

Further, in order to suitably expose the conductive substance in the resin layer on the sleeve surface in the present invention, or in some cases, the filler or the solid lubricant to the surface, or the surface is smoothed to obtain uniform unevenness. In order to make the surface, it is possible to impart more preferable performance by subjecting the surface to a smoothing treatment by means such as polishing described later.
In particular, it is effective for the vertical stripe phenomenon that occurs in solid black and halftone images and the rise of the initial image density, and is particularly effective under high temperature and high humidity.

In the present invention, the operation will be described with reference to FIG. 2 showing an example of the smoothing process of the sleeve. In FIG. 2A, the coating layer (resin layer) 501 is a solid lubricant 50.
2, conductive substance 503, filler 504, binder resin 505
And is coated on the cylindrical substrate 506. By subjecting this to polishing with a belt-like abrasive material having felt or abrasive grains attached thereto, the surface irregularities of the sleeve can be uniformly finished as shown in FIG. 2 (B), so that the toner coating amount on the sleeve is reduced. The toner is homogenized, and as a result, only the toner frictionally charged with the sleeve is conveyed to the developing area. Therefore, it is considered that the above effects can be obtained.

Even after the smoothing treatment as described above, the surface of the coat layer had Ra of JIS B 0601 of 0.
It is preferable to hold irregularities in the range of 2 to 3.5 μm, and more preferable to have irregularities of about 0.3 to 2.5 μm. The reason is the same as above.

Next, a developing method in which the developing sleeve which is the developer carrying member of the present invention is incorporated will be described.

In FIG. 3, an image carrier that carries an electrostatic latent image formed by a known process, such as an electrophotographic photosensitive drum 7, is rotated in the direction of arrow B. The developing sleeve 14 as a developer carrying member carries the toner 10 as a one-component developer supplied from the hopper 9, and is indicated by an arrow A.
By rotating according to the method, the toner 10 is conveyed to the developing portion D where the developing sleeve 14 and the photosensitive drum 7 face each other.
Inside the developing sleeve 14, when the toner 10 is a magnetic toner, a magnet 11 is arranged to magnetically attract and hold the toner on the developing sleeve 14. By friction with the developing sleeve 14, the toner 10 obtains a triboelectric charge capable of developing the electrostatic latent image on the photosensitive drum 7.

In order to regulate the layer thickness of the toner 10 conveyed to the developing section D, a regulating blade 8 made of a ferromagnetic metal in the case of magnetic toner is provided with a gap of about 200 to 300 μm from the surface of the developing sleeve 14. It is suspended from the hopper 9 so as to face the developing sleeve 14 with a certain width. The magnetic lines of force from the magnetic pole N1 of the magnet 11 are concentrated on the blade 8 to form a thin layer of the toner 10 on the developing sleeve 14. A non-magnetic blade may be used as the blade 8. When the toner 10 is a non-magnetic toner, urethane rubber, silicone rubber, or an elastic blade such as a tip blade is used.

Toner 1 formed on developing sleeve 14
The thickness of the thin layer of 0 corresponds to the developing sleeve 14 in the developing section D.
It is preferably thinner than the minimum gap between the photosensitive drum 7 and the photosensitive drum 7. The present invention is particularly effective for a developing device of the type that develops an electrostatic latent image with such a toner thin layer, that is, a non-contact type developing device. However, the present invention can be applied to a developing device in which the thickness of the toner layer in the developing portion is equal to or larger than the minimum gap between the developing sleeve 14 and the photosensitive drum 7, that is, a contact type developing device.

In order to avoid complication of the description, a non-contact type developing device will be taken as an example in the following description.

A developing bias voltage is applied to the developing sleeve 14 from the power source 15 in order to fly the toner 10 which is the one-component developer carried on the developing sleeve 14. When using a DC voltage as this developing bias voltage,
It is preferable that a voltage having a value between the potential of the image portion (the region where the toner 10 is attached and visualized) of the electrostatic latent image and the potential of the background portion is applied to the developing sleeve 14. On the other hand, in order to increase the density of the developed image or improve the gradation, an alternating bias voltage is applied to the developing sleeve 14 so that the developing portion D
An oscillating electric field whose direction is alternately inverted may be formed. In this case, it is preferable to apply to the developing sleeve 14 an alternating bias voltage in which a DC voltage component having a value between the potential of the image portion and the potential of the background portion is superimposed.

Further, in so-called regular development in which toner is made visible by adhering toner to the high potential portion of the electrostatic latent image having the high potential portion and the low potential portion, the toner charged to the opposite polarity to the polarity of the electrostatic latent image is removed. On the other hand, in the so-called reversal development, in which toner is visualized by adhering toner to a low potential portion of the electrostatic latent image, the toner uses a toner charged to the same polarity as the electrostatic latent image.
The high potential and the low potential are expressed by absolute values. In any case, the toner 10 is charged with the polarity for developing the electrostatic latent image by friction with the developing sleeve 14.

FIG. 4 is a block diagram showing another embodiment of the present invention.

In the developing device of FIG. 4, as a member for controlling the layer thickness of the toner 10 on the developing sleeve 14, a material having rubber elasticity such as urethane rubber or silicone rubber, or metal elasticity such as phosphor bronze or stainless steel is used. An elastic plate 17 such as a material having
The feature is that it is pressed against 4. In such a developing device, a thinner toner layer can be formed on the developing sleeve 8. The other configurations of the developing device shown in FIG. 4 are basically the same as those of the developing device shown in FIG. 3, and the same reference numerals as those in FIG. 4 denote the same members.

In the developing device shown in FIG. 4 in which the toner layer is formed on the developing sleeve 14 as described above, since the elastic plate 17 rubs the toner on the developing sleeve 14, the triboelectric charge amount of the toner is large. Therefore, the image density can be improved.

Next, an example of the image forming method having the contact charging / transferring method of the present invention will be described with reference to the schematic diagram of FIG.

Reference numeral 801 denotes a rotary drum type photoconductor, which is rotated clockwise in the drawing at a predetermined peripheral speed (process speed). A charging roller 802 is pressed against the surface of the photoconductor 801 with a pressing force, and is driven to rotate as the photoconductor 801 rotates. Reference numeral 803 denotes a charging bias current V ₂ for applying a voltage to the charging roller 802, and when a bias is applied to the charging roller 802, the surface of the photoconductor 801 is charged to a predetermined polarity / potential. Image exposure 8
An electrostatic charge image is formed by 04, and the toner image is sequentially visualized by the developing unit 805.

A bias V ₁ is applied to the developing sleeve constituting the developing means 805 by the bias applying means 813. The toner image formed on the latent image holding member by development is contact transfer means 806 to which transfer bias V ₃ is applied.
Is electrostatically transferred to the transfer material 808, and the toner image on the transfer material is heated and pressed and fixed by the heating and pressing unit 811.
After the transfer of the toner image, the surface of the photoconductor 801 is cleaned of adhering contaminants such as untransferred toner by a cleaning device 809 equipped with an elastic cleaning blade that is pressed against the photoconductor 801 in the counter direction.
The charge is eliminated by 0, and the image is repeatedly formed.

[0204]

The present invention will be described in more detail with reference to specific examples, but the present invention is not limited thereto.

[0205]   (Production Example of Developer Carrier Having Resin Layer Formed on Surface)   <Development sleeve manufacturing example 1> Phenolic resin intermediate 150 parts by mass Carbon black 5 parts by mass Crystalline graphite 45 parts by mass 41 parts by mass of methanol Isopropyl alcohol 284 parts by mass

A methanol solution of the phenol resin intermediate was diluted with isopropyl alcohol (IPA), carbon black and crystalline graphite were added, and the mixture was dispersed by a sand mill using glass beads. Next, a resin layer was applied onto the sleeve using this paint.

As a developing sleeve, the surface of a stainless steel cylindrical tube having an outer diameter of 32 mm and a wall thickness of 0.8 mm was polished to a cylindrical tube with a runout of 10 μm or less and a surface roughness of Rz notation of 4 μm or less. I was there. This sleeve was erected vertically, rotated at a constant speed, masking the upper and lower ends, and the above paint was applied while lowering the spray gun at a constant speed. Masking width on both ends of the sleeve is 3m
set to m. This is dried and cured in a drying oven at 160 ° C for 20 minutes, and then a belt-like felt is rubbed against the surface of the resin-coated sleeve with a load of 4 kgf and rubbed to perform surface polishing to coat the resin layer with a uniform film thickness. Got a sleeve.

The resin layer has a film thickness of 10 μm and a surface roughness R
“A” was 0.92 μm on average at 6 points, and the pencil hardness was 2H as measured. A magnet was inserted into this sleeve, and flanges were attached to both ends to obtain a developing sleeve 1.

[0209]   <Development sleeve manufacturing example 2> Phenolic resin intermediate 150 parts by mass Carbon black 5 parts by mass Crystalline graphite 45 parts by mass PMMA fine powder (average particle size 0.5 μm) 25 parts by mass 58 parts by mass of methanol Isopropyl alcohol 408 parts by mass

The above materials were dispersed using a sand mill. A solution of the phenolic resin intermediate in methanol is diluted with a portion of isopropyl alcohol (IPA). Carbon black and crystalline graphite were added and dispersed by a sand mill using glass beads. The above-mentioned fine powder of polymethylmethacrylate resin dispersed in the remaining IPA was further added to this as a filler, and further sand mill dispersion was carried out.

Next, using this coating composition, a resin layer was coated on the developing sleeve in the same manner as in Production Example 1 of resin-coated developing sleeve, and then surface polishing was performed. The film thickness of this resin layer is 15 μm, and the surface roughness Ra is 1.15 μ on average at 6 points.
m, and when the pencil hardness was measured, it was 3H. A magnet was inserted into this sleeve, and flanges were attached to both ends to form a developing sleeve 2.

[0212]   <Development sleeve manufacturing example 3> Phenol resin intermediate 125 parts by mass Carbon black 5 parts by mass Crystalline graphite 45 parts by mass 41 parts by mass of methanol Isopropyl alcohol 284 parts by mass

A methanol solution of the phenol resin intermediate was diluted with isopropyl alcohol (IPA), carbon black and crystalline graphite were added, and the mixture was dispersed by a sand mill using glass beads. Next, a resin layer was applied onto the sleeve using this paint.

As the developing sleeve, the surface of an aluminum cylindrical tube having an outer diameter of 16 mm and a wall thickness of 0.8 mm was polished so that the deflection of the cylindrical tube was 10 μm or less and the surface roughness was 4 μm or less in Rz notation. . This sleeve was erected vertically, rotated at a constant speed, masking the upper and lower ends, and the above paint was applied while lowering the spray gun at a constant speed. Masking width on both ends of the sleeve is 3m
set to m. This is dried and cured in a drying oven at 160 ° C for 20 minutes, and then a belt-like felt is rubbed against the surface of the resin-coated sleeve with a load of 4 kgf and rubbed to perform surface polishing to coat the resin layer with a uniform film thickness. Got a sleeve.

The film thickness of this resin layer is 10 μm, and the surface roughness R
a was 6 points average 0.87 μm, and the pencil hardness was 2H. A magnet was inserted into this sleeve, and flanges were attached to both ends to form a developing sleeve 3.

<Developing Sleeve Comparative Production Example 1> As a developing sleeve, the surface of a stainless steel cylindrical tube having an outer diameter of 32 mm and a wall thickness of 0.8 mm was ground to give a deflection of 10 μm.
m and a surface roughness of 4 μm or less in Rz notation were masked at the upper and lower ends, and were made by a blast machine using amorphous alumina abrasive grains (# 300) to obtain 3.92 ×
The blast treatment was performed at a blast pressure of 10 ^-2 MPa (4.0 kgf / cm). Masking width on both ends of the sleeve is 3
It was set to mm. The surface roughness Ra of this blasted sleeve was 1.09 μm on the average of 6 points. A magnet was inserted into this sleeve, and flanges were attached to both ends to form a developing sleeve 4.

(Binder Resin for Toner) The binder resin used in the present invention is as follows. First, a styrene-butyl acrylate-monobutyl maleate copolymer A (St / BA / MBM = 78/2) using tris (t-butylperoxy) triazine as an initiator in the suspension polymerization method.
0/2, Tg = 67 ° C., Mw = 920,000) were produced. Then, by a solution polymerization method, a styrene-butyl acrylate-monobutyl maleate copolymer B (St / BA / M
BM = 83/15/2, Tg = 61 ° C., Mw = 15,0
00) was prepared. A binder resin was obtained by mixing 30 parts by mass of the copolymer A with 70 parts by mass of the copolymer B.

[0218] <Example 1> Binder resin 100 parts Magnetite 100 parts by mass (octahedron, the average particle diameter of ^{0.21μm, BET8.1m 2 /g,σs=85.1A m 2 /} kg, σr = 10.5 Am ² / kg) ・ Low molecular weight polypropylene wax (melting point 130 ° C) 4 parts by mass ・ Condensate (1) 2 parts by mass

The above materials were well premixed by a Henschel mixer, and then melt-kneaded by a twin-screw kneading extruder set at 130 ° C. The obtained kneaded product is cooled and coarsely pulverized by a cutter mill, then finely pulverized by a fine pulverizer using a jet stream, and the finely pulverized product obtained is further classified by an air classifier to obtain finely classified powder. Got the body

To 100 parts by mass of the obtained classified fine powder, silica fine powder produced by a dry method (BET specific surface area: 200 m
² / g) 20 hexamethyldisilazane per 100 parts by mass
1.2 parts by weight of hydrophobic silica treated with 1 part by weight was added and mixed with a Henschel mixer, and sieved with a mesh having an opening of 150 μm to obtain a negatively chargeable one-component magnetic toner 1.

The toner 1 thus obtained was subjected to the following evaluation tests.

[Image Evaluation Test] Commercially available copying machine NP675
0 (manufactured by Canon Inc.), the developing sleeve was replaced with the developing sleeve 1 shown in the developing sleeve manufacturing example of the present invention, 10000 copies were made under normal temperature / normal humidity environment, and normal temperature / low humidity environment, and 10,000 copies were made in each environment of high temperature / high humidity to evaluate image density and fog (evaluation environment: normal temperature / normal humidity (23 ° C / 60% R
H), normal temperature / low humidity (23 ° C / 5% RH), high temperature and high humidity (3
2.5 ° C./80% RH)).

[0223] Further, a part of the surface of the developing sleeve after copying 10,000 sheets under normal temperature / normal humidity environment is wiped clean with ethanol, a solid black image is printed, and the image density before and after the wiping with ethanol is measured, Sleeve contamination was evaluated by calculating the difference. The one with a small concentration difference Δ is good because the influence of contamination is small.

The image density was measured using "Macbeth reflection densitometer" (manufactured by Macbeth Co.). For the fog, a "reflective densitometer" (manufactured by Tokyo Denshoku Gijutsu Center Co., Ltd.) was used to measure the reflective density of the transfer paper and the reflective density of the transfer paper after copying the solid white, and the difference was measured as the fog value. The smaller the value, the better the fog suppression.

[Sleeve Coat Evaluation Test] The toner coat on the sleeve was visually observed and the generation level of blotches was classified into the following ranks (evaluation environment: normal temperature / normal humidity (23 ° C.).
/ 60% RH), normal temperature / low humidity (23 ° C / 5% RH), high temperature and high humidity (32.5 ° C / 80% RH)).

Blotch rank ⊚ (excellent) No occurrence. ○ (Good) Slightly generated at the end of the sleeve. △ (Fair) Very little occurrence, but does not affect the image. × (Not possible) Clearly occurs and affects the image.

The sleeve ghost has a density of 1.3 and a density of 0.
The solid image having a density of 1.0 was copied as an original after the alternating image of the line having a width of 20 mm and a length of 100 mm (process advancing direction) of 05, and was evaluated by the density difference of the density 1.0 part. The smaller the density difference, the better the ghost level.

Evaluation results of these sleeve coatability tests and image evaluation tests are summarized in Tables 1 to 3.

Example 2 In the same manner as in Example 1 except that the condensate (1) was changed to the condensate (2), classified fine powder and toner 2 were obtained.

The toner 2 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Example 3 A classified fine powder and a toner 3 were obtained in the same manner as in Example 1 except that the condensate (1) was changed to the condensate (3).

The toner 3 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Example 4 A classified fine powder and a toner 4 were obtained in the same manner as in Example 1 except that the condensate (1) was changed to the condensate (6).

The toner 4 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Example 5 In the same manner as in Example 1 except that the condensate (1) was changed to the condensate (9), a classified fine powder and a toner 5 were obtained.

The toner 5 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Example 6 A classified fine powder and a toner 6 were obtained in the same manner as in Example 1 except that the condensate (1) was changed to the condensate (10).

The toner 6 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Example 7 In the same manner as in Example 1 except that the condensate (1) was changed to the condensate (11), classified fine powder and toner 7 were obtained.

The toner 7 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

<Example 8> In the same manner as in Example 1 except that the condensate (1) was changed to the condensate (12), a classified fine powder and a toner 8 were obtained.

The toner 8 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Example 9 A classified fine powder and a toner 9 were obtained in the same manner as in Example 1 except that the condensate (1) was changed to the condensate (15).

With respect to this toner 9, the developing sleeve 1 was changed to the developing sleeve 2 and each evaluation was performed in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Example 10 A classified fine powder and a toner 10 were obtained in the same manner as in Example 1 except that the condensate (1) was changed to the condensate (18).

About this toner 10, the developing sleeve 1
Was changed to the developing sleeve 2, and each evaluation was performed in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Comparative Example 1 Example 1 was repeated except that the condensate (1) was changed to a condensate having 98% of the 8-membered ring which is a methylene bond of the unit A of the condensate (14). In the same manner as described above, classified fine powder and toner 11 were obtained.

The toner 11 was evaluated in the same manner as in Example 1. The evaluation results are summarized in Tables 1 to 3.

Comparative Example 2 Evaluations other than the offset resistance test were conducted in the same manner as in Example 1 except that the developing sleeve 1 was changed to the developing sleeve 4. The evaluation results are summarized in Tables 1 to 3.

[0250]

[Table 1]

[0251]

[Table 2]

[0252]

[Table 3]

[0253]   <Example 11> ・ Polyester resin 100 parts by mass (Propoxy bisphenol 52 mol%, terephthalic acid 30 mol%, dodece Nylsuccinic acid 15 mol%, trimellitic acid 4 mol%, Tg = 62 ° C., Mw = 18000) ・ Condensate (14) 2 parts by mass ・ Copper phthalocyanine 3 parts by mass

The above materials were premixed with a Henschel mixer and then kneaded with a twin-screw kneading extruder set at 100 ° C. The obtained kneaded product was cooled and coarsely pulverized with a cutter mill, then finely pulverized with a pulverizer using a jet stream, and classified with a multi-division classifier utilizing the Coanda effect to obtain a volume average diameter of 8. A classified product of 6 μm was obtained. 100 parts by mass of the obtained classified fine powder was mixed with 100 parts of anatase-type titania fine powder (BET specific surface area 100 m ² / g) produced by the sulfuric acid method.
1.5 parts by mass of hydrophobic silica whose mass part was treated with 15 parts by mass of isobutyltrimethoxysilane was added and mixed with a Henschel mixer to obtain a toner 12 sieved with a mesh having an opening of 200 μm.

The toner 12 thus obtained was subjected to the following evaluation tests.

[Image Evaluation Test] Using a commercially available color printer LBP-2030 (manufactured by Canon Inc.), the developing sleeve was replaced with the developing sleeve 3, and 3000 sheets were printed in a normal temperature / normal humidity environment, and a normal temperature / low humidity environment was used. The image density and fog were evaluated by printing 3000 sheets under each environment of high temperature and high temperature / humidity (evaluation environment: normal temperature / normal humidity (23 ° C / 60% RH), normal temperature / low humidity (23 ° C / 5). % RH), high temperature and high humidity (32.5 ° C / 80%
RH)).

A part of the surface of the developing sleeve after copying 3000 sheets under normal temperature / humidity environment was wiped clean with ethanol, a solid black image was printed, and the image density before and after wiping with ethanol was measured. Sleeve contamination was evaluated by calculating the difference. The one with a small concentration difference Δ is good because the influence of contamination is small.

The image density was measured using "Macbeth reflection densitometer" (manufactured by Macbeth Co.). For the fog, a "reflective densitometer" (manufactured by Tokyo Denshoku Gijutsu Center Co., Ltd.) was used to measure the reflective density of the transfer paper and the reflective density of the transfer paper after copying the solid white, and the difference was measured as the fog value. The smaller the value, the better the fog suppression. The fog was measured by measuring the reflection density at 5 points using a reflection densitometer (reflectometer model TC-6DS manufactured by Tokyo Denshoku Co., Ltd.) for the transfer material before the image formation and the white background portion after the image formation, and the average value. Ask for.
The difference in reflection density before and after image formation is used as the evaluation of fog.

[Sleeve Coat Evaluation Test] The toner coat on the sleeve was visually observed and the generation level of blotch was classified into the following ranks (evaluation environment: normal temperature / normal humidity (23 ° C.).
/ 60% RH), normal temperature / low humidity (23 ° C / 5% RH), high temperature and high humidity (32.5 ° C / 80% RH)).

Blotch rank A: It has not occurred at all. B Slightly generated at the sleeve end. C A slight amount is generated, but it does not affect the image. D It occurs clearly and affects the image.

The sleeve ghost has a density of 1.3 and a density of 0.
The solid image having a density of 1.0 was copied as an original after the alternating image of the line having a width of 20 mm and a length of 100 mm (process advancing direction) of 05, and was evaluated by the density difference of the density 1.0 part. The smaller the density difference, the better the ghost level.

[Evaluation of Density Unevenness] Four-tone image (solid,
The middle 2 gradations and highlights) were visually judged. A: All four gradations are rough and have no density unevenness. B: Density unevenness can be confirmed in the halftone portion. C: Density unevenness and roughness are seen in the halftone part, and the uniformity of the highlight part is poor, but there is no problem in practical use. D: Density unevenness is noticeable and practically impossible.

Evaluation results of these sleeve coatability tests and image evaluation tests are summarized in Tables 4 to 6.

[0264]   <Example 12> ・ Polyester resin 100 parts by mass ・ Condensate (18) 2 parts by mass ・ Dimethylquinacridone 3 parts by mass

The above materials were premixed by a Henschel mixer and then kneaded by a twin-screw kneading extruder set at 100 ° C. The obtained kneaded product was cooled and coarsely pulverized with a cutter mill, then finely pulverized with a pulverizer using a jet stream, and classified with a multi-division classifier utilizing the Coanda effect to obtain a volume average diameter of 8. A classified product of 8 μm was obtained. Hydrophobicity obtained by treating 100 parts by mass of the obtained classified fine powder with 100 parts by mass of γ-type alumina fine powder (BET specific surface area 120 m ² / g) produced by a thermal decomposition method with 15 parts by mass of n-butyltrimethoxylane. Add 1.5 parts by mass of silica, mix with a Henschel mixer, and sieve with a mesh of 200 μm mesh toner 13
Got

Using this toner 13, the same running test as in Example 11 was conducted. Tables 4 to 6 show the results of evaluation of developability such as image density, fog and density unevenness.

[0267]

[Table 4]

[0268]

[Table 5]

[0269]

[Table 6]

[0270]

According to the image forming method of the present invention, in the negatively chargeable toner, by using the specific phenol derivative condensate shown in the present invention as the charge control agent, the charging property and the developing property of the toner are greatly improved. By using a developer carrier having a resin layer formed on a metal substrate, it is possible to significantly improve the charge imparting ability and improve the developing characteristics, and to improve the image over a long period of time. It is possible to stably provide a high-definition image free from density reduction, fog, sleeve ghost, blotch, and the like.

[Brief description of drawings]

FIG. 1 is a schematic cross-sectional view of a part of a developer carrier of the present invention.

FIG. 2 is a partial cross section of the developer carrying member of the present invention ((A)).
It is a schematic diagram before polishing, (B) after polishing).

FIG. 3 is an example of a developer replenishing system developing device in which a developer carrier of the present invention is incorporated (a magnetic blade is used as a regulating member).
FIG.

FIG. 4 is a schematic view showing another example (using an elastic blade as a regulating member) of a developer replenishing system developing device in which the developer carrier of the present invention is incorporated.

FIG. 5 is a schematic diagram for explaining an image forming method of the present invention.

[Explanation of symbols]

1 Coating layer (resin layer) 2 Conductive material 3 Filler 4 Binder resin 5 Solid lubricant 6 Cylindrical substrate 7 Photosensitive drum (latent image holder) 8 regulation blade 9 hopper 10 toner 11 magnets 12 Cylindrical substrate 13 Coating layer (resin layer) 14 Development sleeve (developer carrier) 15 power supply 17 Elastic blade A Development sleeve rotation direction B Photosensitive drum rotation direction D development section 501 coating layer (resin layer) 502 Solid lubricant 503 conductive material 504 Filler 505 Binder resin 506 cylindrical substrate 801 latent image holder 801a Photoconductive layer 801b conductive base layer 802 charging roller 802a conductive elastic layer 802b core metal 803 Charging bias power supply 804 image exposure 805 developing roller 806 Transfer roller 806a conductive elastic layer 806b core metal 807 Transfer bias power supply 808 Transfer material 809 Cleaning device 810 Static erasing exposure device 811 heating and pressurizing means 813 Development bias power supply

Continuation of the front page (56) Reference JP-A-9-62030 (JP, A) JP-A-9-50150 (JP, A) JP-A-8-305087 (JP, A) JP-A-7-295299 (JP , A) JP 7-64336 (JP, A) JP 5-341577 (JP, A) JP 4-346360 (JP, A) JP 4-139456 (JP, A) JP 3-237468 (JP, A) JP-A-3-237467 (JP, A) JP-A-2-201378 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (5)

(57) [Claims] 1. A negatively chargeable toner containing at least a binder resin and a charge control agent is conveyed by a developer carrier having a resin layer formed on a metal substrate and is formed on an electrostatic latent image carrier. In an image forming method of forming an electrostatic latent image by transferring a negatively chargeable toner from a developer carrier to form a toner image, the charge control agent is a condensate of phenol or its derivative and an aldehyde. A phenol derivative compound, containing at least two condensates having different numbers of units , including condensates having 4 to 8 units,
An image forming method, wherein the abundance ratio of one kind of condensate is 60% or less, and the condensate is a chain condensate, a cyclic condensate, or a mixture thereof. 2. The phenol derivative compound is a condensate of phenol or its derivative and an aldehyde,
The image forming method according to claim 1, which contains at least three kinds of condensates having different units, and the condensate is a chain condensate, a cyclic condensate, or a mixture thereof. . 3. The phenol derivative compound is a condensate of phenol or its derivative and an aldehyde,
The image forming method according to claim 1 or 2, characterized in that the condensate is a mixture of linear condensate and a cyclic condensate. 4. The condensate has the following general formulas (I) and (I
The image forming method according to any one of claims 1 to 3, characterized in that it comprises a unit represented by I). [Chemical 1] [In the formula, i represents 0 or 1, and when i is 0, R ₁ has a hydrogen atom, a halogen atom, an alkyl group, an optionally substituted aryl group, an aralkyl group, or a substituent. good alicyclic group optionally represent <br/>, when i is 1, R ₁ is an alkyl group, which may have a substituent aryl group, an aralkyl group, which may have a substituent It represents a good alicyclic group , R ₂ represents a hydrogen atom or an alkyl group , R ₃ represents a hydrogen atom or an alkyl group, and R 4 represents a hydrogen atom or an alkyl group . ] 5. The image forming method according to any one of claims 1 to 4 volume-average particle diameter of the toner is equal to or less than 6.0 .mu.m.