JPH11174742A - Electric charge imparting member for electrophotography, electrostatic latent image developer, image forming device and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a high durability electric charge imparting member which ensures rapid kick-off of electrostatic charge, does not reduce the quantity of electric charges at a high temp. and high humidity or extremely increase it at a low temp. and low humidity and prevents the deterioration of a developer due to the peeling of the coating layer of the member by using a phenolic resin having a specified structure. SOLUTION: The electric charge imparting member has a phenolic resin having a structure represented by the formula -(CH2 -A-CH2 -B)n -(I), wherein (n) is an integer of 30-10,000, A is one of arom. skeletons represented by formulae II, III, etc., B is a skeleton having amino groups represented by the formula -NR1 -R3 -NR2 -(IV), etc. In the formulae II and III, at least two of X1 -X6 and at least two of X1 =X8 , are bonding radicals in structural units, at least one of X1 -X6 and at least one of X1 -X8 are hydroxyl and the remainders are each H, halogen, 1-6C alkyl or the like. In the formula IV, R1 and R2 are each H or 1-6C alkyl and R3 is 1-20C alkylene.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic charging member used for developing an electrostatic latent image formed by electrostatic recording in electrophotography, and an electrostatic latent image developer. The present invention relates to a forming apparatus and an image forming method. In the present invention, the electrophotographic charging member is a carrier for developing an electrostatic latent image in a two-component developer,
Irrespective of a two-component system or a one-component system, it refers to a developing sleeve, a blade, and other members for imparting chargeability to toner in a developing device, and may be simply referred to as a "charging member".

[0002]

2. Description of the Related Art Conventionally, in electrophotography, an electrostatic latent image is formed on a photosensitive member or an electrostatic recording member by using various means,
A method of developing an electrostatic latent image by attaching electrostatic fine particles called toner to the electrostatic latent image is generally used. In this development, in a two-component system, carrier particles called a carrier are mixed with toner particles, and both are triboelectrically charged to impart an appropriate amount of positive or negative charge to the toner. Carriers are generally broadly classified into coated carriers having a coating layer on the surface and uncoated carriers having no coating layer on the surface.Coating carriers are superior in consideration of developer life and the like. Therefore, various types of coated carriers have been developed and put into practical use. However, problems in using the two-component developer include a decrease in the charge amount under high temperature and high humidity, an extreme increase in the charge amount under low temperature and low humidity, a binder resin which is a component of the toner, The charge controllability deteriorates over time due to contamination of the carrier surface by the charge control agent, the external additive, and the like.

[0003] In order to solve such problems, a coating with a low surface energy fluoropolymer, silicone polymer, silicone oil or the like, which is superior in environmental stability and surface contamination resistance, has been applied. Coated carriers have been used, and in recent years,
As described in JP-A-51950, JP-A-57-99653, JP-A-60-202451, etc., a fluorine-based polymer or JP-A-60-19156.
JP-A-62-121463, JP-A-61-110
No. 159, JP-A-61-110160, etc., silicone-based polymers and JP-A-3-466.
No. 69, JP-A-3-46670, JP-A-3-4667
As described in JP-A-5-72814, a carrier coated with a resin containing silicone oil or the like has also been proposed.

However, adhesion to the carrier core material,
The abrasion resistance of the resin coating layer is insufficient, the initial value of charging under high temperature and high humidity, low temperature and low humidity varies greatly, the charge distribution spreads to the toner, especially under high temperature and high humidity. There is still room for improvement with respect to environmental stability, such as a decrease in the charge amount of the toner and an extreme increase in the charge amount under low temperature and low humidity. Also, JP-A-3-217857 and JP-A-3-21926
A carrier coated with an amide-based polymer has also been proposed as described in Japanese Patent Publication No. 3 (1993), but there is still room for improvement in environmental stability and charging characteristics.

On the other hand, in the one-component developing system, there are a magnetic toner containing a magnetic powder and a non-magnetic toner not containing a magnetic powder. Use However, since the blade and the developing sleeve are always rubbed with the toner, it is important for these blades and the developing sleeve to maintain an appropriate charge amount for a long time as in the two-component system. In the one-component developing method, Japanese Patent Application Laid-Open No. Hei 3-2046 discloses a method for improving toner contamination.
In Japanese Patent Application Laid-Open Publication No. 64-64, a curable fluorinated copolymer is used as a developing sleeve, but there is a problem in that the ability to impart chargeability to the toner is poor and background fog due to poor charging is caused.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems in the prior art. Therefore, according to the present invention, the charge rise is fast, and the charge amount does not decrease under high temperature and high humidity and the charge amount does not extremely increase under low temperature and low humidity. It is an object of the present invention to provide a highly durable charging member (particularly, a carrier and a developing sleeve) that prevents the occurrence of toner deterioration due to spent toner.

[0007]

Means for Solving the Problems The present inventors diligently studied to solve the above problems, and found that these problems could be solved by using a phenol resin having a specific structure, and reached the present invention. That is, the present invention

(I) A charging member for electrophotography, comprising a phenol resin having a structure represented by the following general formula (1). - Formula _{(1) - (CH 2 -A} -CH 2 -B) n - in the above formulas, n is an integer of 30～10,000, fragrance A is shown below (I) ~ (VIII) One of the tribe skeletons,

[0009]

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[In the above formulas (I) to (VIII), for each structural formula, two of X _{1 to} X ₆ , X _{1 to} X ₈ or X _{1 to} X ₁₀ represent a bond in the structural unit. , At least one of which represents a hydroxyl group, and the rest each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, and 1 to 6 carbon atoms.
Or — (CH ₂ ) _p NR ₂ R
₃ {wherein, p is an integer of 0, R ₂ and R ₃
Each independently represents an alkyl group having 1 to 6 carbon atoms. Represents｝. And B represents the following (IX) or (X)
Is a skeleton having an amino group.

(IX) -NR ₁ -R ₃ -NR _2- [In the above formula (IX), R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms;
₃ represents an alkylene group having 1 to 20 carbon atoms. ]

[0012]

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(Ii) The phenol resin having the structural formula represented by the general formula (1) is represented by the following chemical formulas (2-I) to (2-I)
VIII) one phenol derivative selected from the group consisting of: a diamine compound represented by the following general formula (3) or the following chemical formula (4), or a hydrochloride or a sulfate thereof;
The charging member for electrophotography according to (i), wherein the member is obtained by reacting a hydrogen bromide salt with formaldehyde or a synergistic substance thereof. -General formulas (2-I) to (2-VIII)

[0014]

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In the above formulas (2-I) to (2-VIII), for each formula, ₁ to 4 of X _{1 to} X ₆ , X _{1 to} X ₈ or X _{1 to} X ₁₀ have a hydroxyl group. And the rest are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms,
An alkoxy group having 1 to 6 carbon atoms, or-(CH ₂ ) _p
NR ₂ R ₃ } In the formula, p is an integer of 0 to 10, and R ₂ and R ₃ each independently represent an alkyl group having 1 to 6 carbon atoms. Represents｝.

Formula (3) NR ₁ R ₃ —R ₅ —NR ₂ R _{4 In the} above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a group having 1 to 1 carbon atoms. And R ₅ represents an alkylene group having 1 to 20 carbon atoms.・ Chemical formula (4)

[0017]

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(Iii) The reaction temperature is 60-80.
(Ii) The charging member for electrophotography according to (ii). (Iv) the charging member is a carrier having a phenol resin coating layer having a structure represented by the general formula (1) provided on the surface of a core material; 2. The charging member for electrophotography according to item 1. (V) core material The charging member for electrophotography according to (iv), wherein the average particle diameter is 10 to 150 μm.

(Vi) The charging member for electrophotography according to (iv) or (v), wherein the coating weight of the coating layer of the phenol resin is 0.1 to 10.0% by weight. . (vii) The charging member is a developing sleeve in which a phenol resin coating layer having a structure represented by the general formula (1) is provided on a peripheral surface of a conductive cylindrical substrate (i). (Iii) The charging member for electrophotography according to any one of (1) to (3). (Viii) The thickness of the phenolic resin coating layer is 1 to 500.
(vii) The charging member for electrophotography according to (vii).

(Ix) The electrophotographic device according to (vii) or (viii), wherein the conductive cylindrical substrate is made of one material selected from the group consisting of metals, ceramics, and synthetic resins. It is a charging member. (X) an electrostatic latent image developer comprising a toner and a carrier, wherein the carrier is the charging member according to any one of (iv) to (vi). It is. (Xi) means for forming an electrostatic latent image on the electrostatic latent image holder, means for forming a developer layer on the developing sleeve, and the electrostatic latent image on the electrostatic latent image holder using the developer layer. An image forming apparatus comprising: means for visualizing an image, wherein the developing sleeve is the charging member according to any one of (vii) to (ix).

(Xii) a step of forming an electrostatic latent image on the electrostatic latent image holder, a step of forming a developer layer on the developing sleeve, and a step of forming the developer layer on the electrostatic latent image holder by the developer layer Making the electrostatic latent image visible, and an image forming method comprising:
An image forming method, wherein the developing sleeve is the charging member according to any one of (vii) to (ix). (Xiii) forming an electrostatic latent image on the electrostatic latent image holding member;
An image forming method comprising: forming a developer layer on a developing sleeve; and manifesting an electrostatic latent image on the electrostatic latent image holding member by the developer layer. And an electrostatic latent image developer comprising a carrier and
An image forming method, wherein the carrier is the charging member according to any one of (iv) to (vi).

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. [Phenol resin] The phenolic resin having a structure represented by the following general formula (1) in the present invention is characterized by its structure, particularly from the characteristic of "skeleton having an amino group" of B in general formula (1), It shows high charging ability and has excellent environmental stability as a whole structure. Therefore, the charging member having such a resin can provide a stable charging property to the toner, and can maintain a high-quality image in electrophotography for a long period of time.

General formula (1) — (CH ₂ —A—CH ₂ —B) _n — In the above formula, n is an integer of 30 to 10,000, and A represents the following (I) to (VIII) ) Is one of the aromatic skeletons,

[0024]

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[In the above formulas (I) to (VIII), two of X _{1 to} X ₆ , X _{1 to} X ₈ or X _{1 to} X ₁₀ represent a bond in the structural unit for each structural formula. , At least one of which represents a hydroxyl group, and the rest each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, and 1 to 6 carbon atoms.
Or — (CH ₂ ) _p NR ₂ R
₃ {wherein, p is an integer of 0, R ₂ and R ₃
Each independently represents an alkyl group having 1 to 6 carbon atoms. Represents｝. And B represents the following (IX) or (X)
Is a skeleton having an amino group.

(IX) -NR ₁ -R ₃ -NR _2- [In the above formula (IX), R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms;
₃ represents an alkylene group having 1 to 20 carbon atoms. ]

[0027]

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When n in the phenolic resin having the structure represented by the above general formula (1) in the present invention is less than 30, the strength as a resin becomes insufficient, and when n is more than 10,000, the coating strength is reduced. Each of these is not preferred because solubility in a solvent is reduced. In the present invention, the “bond” is a phenol derivative having a structural formula represented by one general formula selected from the group consisting of general formulas (2-I) to (2-VIII) described later, a moiety occurs and formaldehyde are reacted in the presence of aqueous ammonia or alkali hydroxide, mainly have the form of a -CH ₂ OH,
This reacts and has thermosetting properties.

The phenolic resins having the structural formula represented by the general formula (1) are represented by the following chemical formulas (2-I) to (2-I).
One phenol derivative selected from the group consisting of VIII) and a diamine compound represented by the following general formula (3) or the following chemical formula (4), or a salt thereof, for example, hydrochloride, sulfate, hydrogen bromide and the like And formaldehyde or the same active substance.
-General formulas (2-I) to (2-VIII)

[0030]

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In the above formulas (2-I) to (2-VIII), for each formula, ₁ to 4 of X _{1 to} X ₆ , X _{1 to} X ₈ or X _{1 to} X ₁₀ have a hydroxyl group. And the rest are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms,
An alkoxy group having 1 to 6 carbon atoms, or-(CH ₂ ) _p
NR ₂ R ₃ } In the formula, p is an integer of 0 to 10, and R ₂ and R ₃ each independently represent an alkyl group having 1 to 6 carbon atoms. Represents｝.

General formula (3) NR ₁ R ₃ —R ₅ —NR ₂ R _{4 In the} above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or a group having 1 to 1 carbon atoms. And R ₅ represents an alkylene group having 1 to 20 carbon atoms.・ Chemical formula (4)

[0033]

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Examples of the phenol derivative represented by the general formula (3) in the present invention include those described in the following Tables 1 to 9, but the present invention is not limited thereto.

[0035]

[Table 1]

[0036]

[Table 2]

[0037]

[Table 3]

[0038]

[Table 4]

[0039]

[Table 5]

[0040]

[Table 6]

[0041]

[Table 7]

[0042]

[Table 8]

[0043]

[Table 9]

The diamine compound represented by the general formula (3) includes a hydrogen atom that can participate in the reaction with the phenol derivative represented by the above formulas (2-I) to (2-VIII). It is necessary to have in the skeleton, for example, aliphatic 1 or 2 represented by ethylenediamine, 1,3-propylenediamine, 1,6-hexamethylenediamine, N, N-dimethylethylenediamine, piperazine, etc.
Grade diamino compounds or their hydrochlorides, sulfates and hydrobromides. In addition to these, any other aliphatic primary or secondary diamino compounds having a hydrogen atom capable of participating in the reaction with the phenol derivative in the skeleton and salts thereof can be used. Further, as a substance equivalent to formaldehyde used in the present invention, formalin gas, formalin aqueous solution,
Paraformaldehyde can be mentioned.

As a method for producing a phenolic resin having the structure represented by the general formula (1) in the present invention, a similar method for a specific phenol derivative is described in JP-A-49-34997. .

As a production method, a phenol resin having a structure represented by the general formula (1) obtained by the following method is particularly effective as a charging member for electrophotography. The phenol derivative selected from the group consisting of the chemical formulas (2-I) to (2-VIII) is equimolar to 1.5 times the molar amount of the phenol derivative of the general formula (3) or the chemical formula (4). With a diamine compound or a salt thereof, and 1.5 to 4 moles of formalin gas,
Formalin aqueous solution or paraformaldehyde,
By reacting at 60 to 80 ° C. in a solvent-free or medium, a phenol resin having the structure represented by the general formula (1) can be obtained. At this time, an acidic substance can be added as a catalyst to promote the reaction.

Examples of the acidic substance which can be added as a catalyst include Lewis acids such as p-toluenesulfonic acid, sulfuric acid, and hydrochloric acid. ) Is preferably 1/1000 to 1/10 times the molar amount of 1 phenol derivative selected from the group consisting of
/ 100-fold molar amount.

The desired phenolic resin can be obtained by neutralizing the reaction solution after completion of the reaction. Further, as a medium used for the reaction, water, methyl alcohol,
Examples thereof include alcohols having 1 to 4 carbon atoms such as ethyl alcohol, ketones such as acetone and methyl ethyl ketone, and aromatic derivatives such as toluene.

[Specific Synthesis Example of Phenol Resin] Hereinafter, a specific synthesis example of the phenol resin having the structure represented by the general formula (1) in the present invention will be described in detail. It is not limited to these.

(Synthesis Example 1) To 9.4 g (0.10 mol) of the compound No. 1 while stirring, 16.2 g (6.0 g (0.20 mol) as formalin) of 37% aqueous formaldehyde solution and 8.6 g of piperazine
(0.10 mol) and 0.20 of 37% hydrochloric acid aqueous solution
g (0.074 g (2.0 mmol) as hydrochloric acid) at 20-30 ° C. 20 ~ 25 ° C
And react for 24 hours. As the reaction proceeds, solids precipitate.

After completion of the reaction, 50 ml of water was added to adjust the pH to 7 to 8 with saturated aqueous sodium hydrogen carbonate, and the precipitated solid was filtered by suction, washed with water, and dried at 30 ° C. in a vacuum drier. After the obtained solid was reprecipitated with tetrahydrofuran / n-hexane, it was dried at 30 ° C. in a vacuum drier to obtain 20.5 g of a white powder. When the H ¹ NMR spectrum of the obtained white powder was measured, it was confirmed that a methylene bond was present at 3.0 to 4.0 ppm and 2.0 to 3.0 p.
pm is a proton of a piperazine skeleton, 6.6 to 7.2 pp
A phenyl proton was identified in m. The molecular weight of this product (polymer) was measured by gel permeation chromatography (in terms of polystyrene gel) and found to be 24,000 in weight average molecular weight. Also,
The n of the polymer was calculated to be about 120.

(Synthesis Example 2) Instead of piperazine of Synthesis Example 1, 8.81 g of N, N'-dimethylethylenediamine
The reaction was carried out in the same manner as in Synthesis Example 1 except that (0.10 mol) was used, to obtain 18.5 g of a pale yellow powder. The H ¹ NMR spectrum of the obtained pale yellow powder was measured in the same manner as in Synthesis Example 1. As a result, it was confirmed that a methylene bond was present at 3.0 to 4.0 ppm, and 1.0 to 2.0 pp.
A methyl proton was observed at m, and a phenyl proton was observed at 6.6 to 7.2 ppm. The molecular weight of this product was measured by gel permeation chromatography (in terms of polystyrene gel) and found to be 28,000 in weight average molecular weight. Further, n of the polymer is about 14
It was calculated as 0.

(Synthesis Example 3) In place of the compound of No. 1, 13.7 g of the compound of 3
(0.10 mol), and the same as Synthesis Example 1 except that 6.0 g (0.20 mol) of paraformaldehyde was used instead of the aqueous formaldehyde solution, and 60 g of toluene was used as the medium. the reaction to obtain a brownish white powder 17.5g performed in. the obtained brownish white powder, in the same manner as in synthesis example 1 was measured for H ¹ NMR spectra, 3.0Ppm～4.0Ppm
Is confirmed to have a methylene bond,
2.0 ppm to methyl protons, 6.6 to 7.2 ppm
Phenyl protons were respectively confirmed. The molecular weight of this product was measured by gel permeation chromatography (in terms of polystyrene gel) and found to be 25,000 in weight average molecular weight. Further, n of the polymer
Was calculated to be about 100.

(Synthesis Example 4) No. 1 in Table 6 was used instead of the compound of No. 1. 32.1 g of compound of 24
The reaction was carried out in the same manner as in Synthesis Example 2 except that (0.10 mol) was used to obtain 28.5 g of a white powder. When the H ¹ NMR spectrum of the obtained white powder was measured in the same manner as in Synthesis Example 1, it was confirmed that a methylene bond was present at 3.0 ppm to 4.0 ppm, and 1.0 to 2.0 p.
A methyl proton was observed at pm, and a phenyl proton was observed at 6.6 to 7.2 ppm. The molecular weight of this product was measured by gel permeation chromatography (in terms of polystyrene gel) and found to be 25,000 in weight average molecular weight. Further, n of the polymer is about 6
It was calculated as 0.

(Synthesis Example 5) In place of the compound of No. 1, 8.59 g of compound 34
(0.05 mol) and 8.8 g (0.05 mol of piperazine dihydrochloride monohydrate) instead of piperazine.
Except for using l), the reaction was carried out in the same manner as in Synthesis Example 1 to obtain 17.5 g of a pale yellow powder. When the H ¹ NMR spectrum of the obtained pale yellow powder was measured in the same manner as in Synthesis Example 1, it was confirmed that a methylene bond was present at 3.0 ppm to 4.0 ppm, and methyl was present at 1.0 to 2.0 ppm. Proton and phenylpronto were found at 6.6 to 7.2 ppm, respectively. When the molecular weight of this product was measured by gel permeation chromatography (in terms of polystyrene gel), the weight average molecular weight was 38.0.
00. Further, n of the polymer was calculated to be about 40.

(Synthesis Example 6) 34 compounds
No. in the above Table 9 in place of 35 compounds 16.8
Same as Synthesis Example 5 except that g (0.05 mol) was used.
To obtain 25.5 g of a pale yellow powder. Got
About pale yellow powder, H ¹NMR spec
When the vector was measured, it was 3.0 ppm to 4.0 ppm.
Is confirmed to have a methylene bond, and 6.6 to
A phenyl proton was confirmed at 7.2 ppm. This raw
Gel Permeation Chromatography for Molecular Weight of Products
-(In terms of polystyrene gel)
The average molecular weight was 38,000. In addition, the polymer
n was calculated to be about 85.

[Charging Member] In the present invention, the charging member is, as described above, a carrier, a developing sleeve, a blade, and other members for providing charging to the toner.
The charging member of the present invention should be a support for these,
It can be obtained by providing a coating layer of a phenol resin having a structure represented by the general formula (1) on a surface (peripheral surface) of a core material or a conductive cylindrical substrate. Hereinafter, the case where the charging member of the present invention is a carrier and a developing sleeve will be described.

1. Carrier When a phenol resin having a structure represented by the general formula (1) is to be used as a carrier for electrophotography, the core material to be coated has a volume average particle diameter of 10 to 150 μm.
m, magnetic metal powders such as iron, copper, nickel, and cobalt, and those in which these are dispersed in a resin; magnetite, magnetic oxide powders such as ferrite, and those in which these are dispersed in a resin. The coating amount is usually 0.1 to 10.0% by weight based on the core material, preferably 0.5 to
8.0% by weight. For the purpose of controlling the resistance, these coating layers may contain a resistance controlling agent such as carbon black, tin oxide or titanium oxide.

Examples of the method of coating the surface of the core with a phenol resin having the structure represented by the general formula (1) include, for example, an immersion method in which the core material powder is immersed in a solution for forming the coating, and a method of forming the coating. A technique known in the art, such as a spray method for spraying a solution for core onto the surface of a core material, a fluidized bed method for spraying a solution for forming a coating layer while the core material is suspended by flowing air, and a kneader coater method, can be used.

2. Developing Sleeve When a phenol resin having the structure represented by the general formula (1) is to be used as a developing sleeve for electrophotography,
Examples of the conductive cylindrical substrate to be coated include aluminum and stainless steel. As a method of forming the phenolic resin coating layer on these substrates, for example, an immersion method in which a conductive cylindrical substrate is immersed in a coating layer forming solution,
A spray method of spraying the coating layer forming solution onto the surface of the conductive cylindrical substrate is exemplified. The solution for forming the coating layer is obtained by dissolving the phenol resin in a suitable solvent. Any solvent can be used as long as it can dissolve the phenol resin. For example, toluene, tetrahydrofuran, dimethylformamide, chloroform and the like can be used. In the case of the developing sleeve, the layer thickness of the coating layer is usually 1 to 500 μm,
Preferably, the range is 5 to 300 μm. In addition, carbon black, tin oxide,
A resistance controlling agent such as titanium oxide may be contained.

[Electrostatic Latent Image Developer] The carrier as the charging member of the present invention is used as a two-component developer by mixing with a toner. The toner used here is
It can be obtained by pulverizing and classifying a mixture obtained by adding a colorant and other additives to a binder resin and melt-kneading the mixture according to a conventional method. Further, these toners can also be used as a one-component developer without using a carrier. In this case, charging the toner by friction with the developing sleeve or blade, which is the charging member of the present invention, not only ensures sufficient charging properties but also increases the durability of the charging member.

Examples of the binder resin of the toner include polyester, polyurethane, polyurea, polystyrene, styrene-alkyl methacrylate copolymer, styrene-alkyl acrylate copolymer, styrene-acrylonitrile copolymer, and styrene-butadiene copolymer. And styrene-maleic anhydride copolymer, polyethylene, polypropylene and the like, and these may be contained alone or in a mixed state.

The coloring agents for the toner include carbon black, nigrosine, aniline blue, calcoil blue, chrome yellow, ultramarine blue Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, and lamp black. , Rose Bengal, C.I.
I. Pigment Red 48: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 57:
1, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12, C.I. I. Pigment Blue 1
5: 1, C.I. I. Pigment Blue 15: 3, magnetic powder and the like can be exemplified as typical examples.

The toner may optionally contain known additives such as a charge control agent and a fixing aid. Also,
An external additive such as a fluidizing agent such as silica, titania, or alumina, a cleaning aid such as polystyrene fine particles, polymethyl methacrylate fine particles, or polyvinylidene fluoride fine particles, or a transfer aid can also be used. The volume average particle diameter of these toners is preferably 30 μm or less, more preferably 3 to 20 μm. When such a toner and the carrier are mixed and used as a two-component developer, the ratio of the toner is 0.3 to 30% of the entire developer.
% By weight.

[Image Forming Apparatus and Method] The charging member of the present invention obtained as described above includes a means for forming an electrostatic latent image on an electrostatic latent image holding member, and a developer on a developing sleeve. The present invention can be applied to an image forming apparatus having means for forming a layer and means for using the developer layer to make an electrostatic latent image on the electrostatic latent image holding member visible. That is, as the developer in the image forming means, a developer using the carrier, which is the charging member of the present invention, can be used. Also,
As the developing sleeve in the image forming apparatus, the developing sleeve which is the charging member of the present invention can be used.

Similarly, the charging member of the present invention comprises a step of forming an electrostatic latent image on an electrostatic latent image holding member, a step of forming a developer layer on a developing sleeve, and a step of forming the developer layer. And a step of visualizing an electrostatic latent image on the electrostatic latent image holding member using the image forming method. That is, as the developer in the image forming method, a developer using the carrier, which is the charging member of the present invention, can be used. Further, as the developing sleeve in the image forming method, the developing sleeve which is the charging member of the present invention can be used.

[0067]

The present invention will be described below in detail with reference to examples. Carrier Example 1 The phenolic resin obtained in Synthesis Example (1) was dissolved by adding tetrahydrofuran so as to have a solid content of 20% by weight. C with a volume average particle size of 50 μm as the core material of the carrier
Using a u-Zn ferrite particle, the phenol resin solution was added to 100 parts by weight of the particle so that the solid content in the solution became 1.5 parts by weight, and a 1-liter small kneader equipped with a heater was added. After mixing at 50 ° C. for 30 minutes in the mixture, the mixture was cooled while stirring, and sieved with a 75 μm sieve to produce a coated carrier having a thickness of 2 μm.

Carrier Example 2 The phenol resin obtained in Synthesis Example (2) was dissolved by adding methyl ethyl ketone so as to have a solid content of 20% by weight. Magnetite particles having a volume average particle diameter of 40 μm were used as a core material of the carrier, and the phenol resin solution was used in an amount of 2.0 wt.
Parts by weight, and add 10 with a kneader coder.
Coating was performed at 0 ° C. for 30 minutes. Next, the heater was turned off, and the mixture was cold-marked with stirring and sieved with a 75 μm sieve to obtain a coated carrier having a thickness of 2 μm.

Carrier Example 3 The phenol resin obtained in Synthesis Example (3) was dissolved by adding methyl ethyl ketone so as to have a solid content of 20% by weight. Magnetite particles having a volume average particle size of 50 μm were used as a core material of the carrier, and the phenol resin solution was added to the phenol resin solution in an amount of 1.5 wt.
Add so that it becomes 10 parts by weight.
Coating was performed at 0 ° C. for 30 minutes. Next, the heater was turned off, cooled with stirring, and sieved with a 75 μm sieve to obtain a coated carrier having a thickness of 2 μm.

Carrier Example 4 The phenol resin obtained in Synthesis Example (4) was dissolved by adding methyl ethyl ketone so as to have a solid content of 20% by weight. Carbon black particles having an average particle size of 0.25 μm (trade name: Vulcan XC72) were added as a resistance control material to the phenol resin obtained in Synthesis Example (4) in an amount of 20% by weight and dispersed for 20 minutes. Magnetite particles having a volume average particle diameter of 50 μm are used as the core material of the carrier, and the phenol resin-carbon black particle mixture is mixed with 100 parts by weight of the particles so that the solid content in the solution is 1.5 parts by weight. 100 ° C with a kneader coater
For 30 minutes. Next, the heater was turned off, cooled with stirring, and sieved with a 75 μm sieve to obtain a coated carrier having a thickness of 2 μm.

Carrier Comparative Example 1 The procedure of Carrier Example 1 was repeated, except that a commercially available phenol resin was used, to obtain a coated carrier, which was designated as Carrier Comparative Example 1.

Carrier Comparative Example 2 As the polyester resin in Carrier Example 6,
4,4'-dihydroxy-2,3,5,6,2 ',
3 ', 5', 6'-octabromodiphenyl sulfone /
Sebacic acid copolymer (weight average molecular weight (Mw) 40,0
Using a core permeation chromatographic value of 00, Cu-Zn having a volume average particle size of 50 μm used for the core was used.
A coated carrier was obtained in the same manner as in Example 6, except that the ferrite particles were coated with 3-aminopropyltrimethoxysilane.
And

[Toner for Measurement] Linear polyester resin (linear polyester obtained from terephthalic acid / bisphenol A ethylene oxide adduct / cyclohexanedimethanol): Tg = 62 ° C., Mn = 4,000, Mw = 35,000, acid value = 12, hydroxyl value = 25) 100% by weight Magenta pigment (CI Pigment Red 57) 3% by weight The mixture having the above composition was kneaded with an extruder and pulverized with a jet mill. Then, d ₅₀ = 8 dispersed by a wind classifier
μm magenta toner particles were used as the toner for measurement.

[Electrostatic latent image developer] Toner 8 for the above measurement
Carrier Examples 1-4 and Carrier Comparative Example 1 in parts by weight
100 parts by weight of each of the carriers No. 2 to No. 2 were mixed to prepare an evaluation developer. [Evaluation Test of Carrier] Using these developers, an electrophotographic copying machine (A-Color630, manufactured by Fuji Xerox Co., Ltd.) was used. A copy test was performed by copying a test pattern including an image and a character under the conditions of 55%) and low temperature and low humidity (15 ° C, 10%). Table 10 shows the results. The evaluation items, evaluation methods and evaluation criteria are as follows.

(1) Initial Image The sensory evaluation of the copied image in the initial stage was performed under the condition of medium temperature and humidity. (2) Toner charge amount The charge amount of each toner was measured after 10 copies under high-temperature, high-humidity, medium-temperature, medium-humidity, and low-temperature, low-humidity conditions, and after 10.000 copies under medium-temperature, medium-humidity conditions. . The charge amount is C
This is a value obtained by surface image analysis of SG (charge spectrograph method). (3) Observation by Electron Microscope The surface state of each carrier after 10,000 copies was observed with an electron microscope (about 10,000 times).

[0076]

[Table 10]

Carrier In the case of the developers using the carriers of Examples 1 to 7, all the images without fog and density unevenness were obtained as shown in Table 10. Further, the image density is 1.3.
The toner charge amount was stable before and after and showed a stable toner charge amount even with environmental fluctuations. Further, the surface of the carrier after 10,000 copies was observed by an electron microscope, and the presence or absence of peeling of the carrier coating material was examined. For each of the carriers of Carrier Examples 1 to 7, the coating materials were all as shown in Table 10. No peeling was observed, and no attachment of external additives and toner components to the carrier surface was observed.

On the other hand, in the case of the developer using the carrier of Carrier Comparative Example 1, the environmental fluctuation is large, and in the case of the developer using the carrier of Carrier Comparative Example 2, the toner charge amount is low. It was unstable against environmental changes. Further, the charge amount of the toner after 10,000 copies was significantly reduced. The surface of each carrier of Comparative Carrier Examples 1 and 2 after 10,000 copies was observed with an electron microscope. It was observed that the material was peeled off, and that an external additive was embedded on the carrier surface and the toner component was attached.

Developing Sleeve Example 1 The phenol resin obtained in Synthesis Example (5) was dissolved by adding methyl ethyl ketone so as to have a solid content of 20% by weight. Using this phenol resin solution as a coating solution, a coating layer having a thickness of 2.5 μm was formed on the surface of a developing sleeve (made of stainless steel) for a laser printer 4105 manufactured by Fuji Xerox Co., Ltd. by a dipping coating method, and then heated to 100 ° C. in a heating chamber. For 30 minutes to obtain a developing sleeve as a charging member.

Developing sleeve Example 2 The phenolic resin obtained in Synthesis Example (6) was added to tetrahydrofuran so as to have a solid content of 20% by weight and dissolved, and then carbon black having an average particle size of 0.25 μm was used as a resistance control material. Particles (trade name: Vulcan XC72) were added to the phenol resin in an amount of 20% by weight and dispersed for 20 minutes. Using this phenol resin-carbon black particle mixed solution as a coating solution, a developing sleeve for laser printer 4105 manufactured by Fuji Xerox Co., Ltd. (made of stainless steel)
A coating layer having a thickness of 2.5 μm was formed on the roll sleeve on the surface by a dipping coating method, and then dried at 90 ° C. for 30 minutes to obtain a developing sleeve as a charging member.

Developing Sleeve Comparative Example 1 A developing sleeve (made of stainless steel) for a laser printer 4105 manufactured by Fuji Xerox Co., Ltd. was used as it was, and this was designated as developing sleeve comparative example 1.

Developing Sleeve Comparative Example 2 A developing sleeve was obtained by performing the same processing as in the developing sleeve Example 1 except that a commercially available phenol resin was used. .

[Toner for Measurement] As the toner for measurement, the above-described magenta toner used in the carrier examples was used.

[Evaluation of Developing Sleeve] Each developing sleeve obtained in developing sleeve examples 1 and 2 and developing sleeve comparative examples 1 and 2 was attached to a laser printer 4105 modified machine manufactured by Fuji Xerox Co., Ltd. An image quality evaluation test was performed by copying a test pattern including an image and a character using a toner for printing. The evaluation was performed by sensory evaluation of the density of the solid portion and the presence or absence of stains on the background portion between the initial stage and after copying 10,000 sheets. Table 11 shows the results.

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[Table 11]

[0086]

The charging member for developing an electrostatic image of the present invention has a rapid rise of charging, and does not have a decrease in the charge amount under high temperature and high humidity and no extreme increase in charge amount under low temperature and low humidity. In particular, when the charge imparting member of the present invention is a carrier, the adhesion to the core material and the abrasion resistance of the resin coating layer are excellent, the deterioration of the developer due to the separation of the core material and the coating layer can be prevented, and the toner can be spent. Deterioration does not occur, has high durability, and can maintain good charging ability even when used continuously for a long time.

Claims (13)

[Claims] 1. An electrophotographic charging member comprising a phenolic resin having a structure represented by the following general formula (1). - Formula _{(1) - (CH 2 -A} -CH 2 -B) n
In the above formula, n is an integer of 30 to 10,000, A is any of the aromatic skeletons of the following (I) to (VIII), [In the above formulas (I) to (VIII), X ₁ to
Two of X ₆ , X _{1 to} X ₈ or X _{1 to} X ₁₀ represent a bond in the structural unit, at least one of them represents a hydroxyl group, and the rest each independently represent a hydrogen atom, a halogen atom,
An alkyl group having 1 to 6 carbon atoms, an alkoxy group having 1 to 6 carbon atoms, or — (CH ₂ ) _p NR ₂ R ₃ , wherein p is 0
Is an integer of 10 to 10, and R ₂ and R ₃ each independently represent an alkyl group having 1 to 6 carbon atoms. Represents｝. ], B
Is a skeleton having an amino group of (IX) or (X) shown below. (IX) -NR ₁ -R ₃ -NR _2- [In the above formula (IX), R ₁ and R ₂ each independently represent a hydrogen atom or an alkyl group having 1 to 6 carbon atoms.
₃ represents an alkylene group having 1 to 20 carbon atoms. [Chemical formula 2] 2. A phenol resin having a structural formula represented by the general formula (1) is represented by the following chemical formulas (2-I) to (2-VII).
One phenol derivative selected from the group consisting of I),
A compound obtained by reacting a diamine compound represented by the following general formula (3) or the following chemical formula (4), or a salt thereof, with formaldehyde or an equivalent substance thereof. 2. The charging member for electrophotography according to 1. -General formulas (2-I) to (2-VIII) In each of the above formulas (2-I) to (2-VIII), X _{1
1 to 4} of X _{1 to} X ₆ , X _{1 to} X ₈ or X _{1 to} X ₁₀ each represent a hydroxyl group, and the rest independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 6 carbon atoms, 1-6
Or — (CH ₂ ) _p NR ₂ R
₃ {wherein, p is an integer of 0, R ₂ and R ₃
Each independently represents an alkyl group having 1 to 6 carbon atoms. Represents｝. General formula (3) NR ₁ R ₃ —R ₅ —NR ₂ R _{4 In the} above formula, R ₁ , R ₂ , R ₃ and R ₄ are each independently a hydrogen atom or an alkyl having 1 to 6 carbon atoms. R ₅ represents an alkylene group having 1 to 20 carbon atoms. -Chemical formula (4) 3. The charging member for electrophotography according to claim 2, wherein the reaction temperature is 60 to 80 ° C. 4. The charge providing member according to claim 1, wherein the charge providing member is a carrier having a phenol resin coating layer having a structure represented by the general formula (1) provided on a surface of a core material.
4. The charging member for electrophotography according to any one of the above items 3 to 3. 5. The core material has a volume average particle size of 10 to 150.
The charging member for electrophotography according to claim 4, wherein the thickness is μm. 6. The coating weight of the phenolic resin coating layer is as follows:
The charging member for electrophotography according to claim 4, wherein the content is 0.1 to 10.0% by weight. 7. The charging sleeve according to claim 1, wherein the charging member is a developing sleeve having a phenol resin coating layer having a structure represented by the general formula (1) provided on a peripheral surface of the conductive cylindrical substrate. Item 4. The charging member for electrophotography according to any one of Items 1 to 3. 8. The phenolic resin coating layer has a thickness of 1 to 10.
The charging member for electrophotography according to claim 7, wherein the thickness is 500 μm. 9. The electrophotographic charging member according to claim 7, wherein the conductive cylindrical substrate is made of one material selected from the group consisting of a metal, a ceramic, and a synthetic resin. . 10. An electrostatic latent image developer comprising a toner and a carrier, wherein the carrier is the charging member according to any one of claims 4 to 6. . 11. A means for forming an electrostatic latent image on an electrostatic latent image holder, a means for forming a developer layer on a developing sleeve,
Means for visualizing an electrostatic latent image on the electrostatic latent image holding member by the developer layer, wherein the developing sleeve is provided with a charge according to any one of claims 7 to 9, wherein An image forming apparatus, which is a member. 12. A step of forming an electrostatic latent image on an electrostatic latent image holder, a step of forming a developer layer on a developing sleeve,
Making the electrostatic latent image on the electrostatic latent image carrier visible by the developer layer. The method according to claim 7, wherein the developing sleeve comprises: An image forming method, which is a member. 13. A step of forming an electrostatic latent image on an electrostatic latent image holding member, a step of forming a developer layer on a developing sleeve,
Making the electrostatic latent image on the electrostatic latent image holding member visible by the developer layer, wherein the developer is an electrostatic latent image developer comprising a toner and a carrier. An image forming method, wherein the carrier is the charging member according to any one of claims 4 to 6.