JP2582206B2 - Electrophotographic equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic separation claw, and more particularly to a surface modification of a separation claw. In particular, the present invention relates to an invention in which a separation claw is provided with releasability to accurately separate paper.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus, primary charging, formation of an electrostatic latent image by image exposure, development with toner charged to a polarity opposite to that of the electrostatic image, transfer of a toner image to plain paper,
The process of fixing, removing the residual toner on the drum by the cleaning device, and removing the charge on the drum by strong exposure is repeatedly performed.

In the fixing step, a separating claw is used to improve the offset property of the paper. Especially when the humidity is high during the rainy season, it is difficult to separate the supply paper. Conventionally, in order to prevent the toner from adhering to the separation claw, it has been proposed to coat the surface of the separation claw made of polyamideimide with a fluorine-containing resin and then bake it (Japanese Patent Publication No. 61-23554). No.).

[0004]

However, in the case of the separation claw produced by the above method, if the separation claw is repeatedly used at 200 ° C. or more, the surface of the fluorine-containing resin film may be damaged or may be partially peeled off. In addition, there is a problem that the releasability of the toner is reduced and the image quality is deteriorated. In addition, since the baking temperature of the fluorine-containing resin is relatively high, the resin is damaged or the resin used is limited.

SUMMARY OF THE INVENTION The present invention has been made in view of the conventional drawbacks, and has as its object to provide a separation claw having excellent durability and releasability, and to provide an electrophotographic apparatus having excellent image quality. .

[0006]

In order to achieve the above object, an electrophotographic apparatus according to the present invention has an electrophotographic photosensitive member,
In an electrophotographic apparatus for obtaining a copied image by a process including each step of charging, image exposure, development, transfer, fixing, and cleaning, a siloxane bond (shared) is formed on a surface of a separation claw used for offsetting a paper. Thickness ) containing fluorinated alkyl groups via
It is characterized in that a chemical adsorption film at the level of Angstrom is provided.

In the above structure, it is desirable that the chemical adsorption film is a monomolecular film or a polymer film.

[0008]

The separating claw used in the electrophotographic apparatus of the present invention is
Since a chemically adsorbed film containing a fluorinated alkyl group is formed on the surface by chemical bonding via a siloxane bond, releasability is excellent. That is, since the alkyl fluoride group is present on the surface layer of the chemical adsorption film, the releasability is excellent, and the toner does not easily adhere. Further, since the base of the chemical adsorption film is formed by a chemical bond (covalent bond) via a siloxane bond, the film can have excellent durability. The chemisorption film does not easily peel off from the separation nail surface. Further, since the chemisorption film of the present invention is an extremely thin film in a unit of nanometer or angstrom, characteristics such as mechanical strength of the separation claw are not impaired. In addition, the chemisorption film of the present invention does not require a baking step, so that the range of resin to be used is widened and, at the same time, a high-quality separation claw can be formed without causing thermal deterioration of the resin during processing.

Further, according to the preferred structure of the present invention in which the chemical adsorption film is a monomolecular film, a thin film having a uniform thickness can be obtained without affecting the dimensional accuracy of the separation claw. Further, when a chemically adsorbed polymer film is used, the film is slightly thicker than a monomolecular film, but can be a dense film.

[0010]

The present invention will be described more specifically with reference to the following examples. The electrophotographic apparatus of the present invention, as shown in FIG.
A separation nail having a monomolecular film 3 containing an alkyl fluoride group formed on the surface of the separation nail 1 via a siloxane bond 2 is used.

For example, polyamide imide is often used as a material for the separation nail. As another resin, a heat-resistant resin such as polyimide, aromatic polyamide (aramid), and PEEK can be used. In some cases, engineering plastics such as polyester, polyamide, polyacetal, and polycarbonate can also be used.

The chemical adsorption film provided on the surface of the separation nail used in the electrophotographic apparatus of the present invention is made of a chlorosilane-based surfactant having an alkyl fluoride group. Examples of the chlorosilane-based surfactant having a fluorinated alkyl group (fluoroalkyl group) include CF ₃ (CF ₂ ) ₇ (C
H ₂ ) ₂ SiCl ₃ , CF ₃ CH ₂ O (CH ₂ ) ₁₅ Si
Cl ₃ , CF ₃ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (C
H ₂ ) ₁₅ SiCl ₃ , CF ₃ (CF ₂ ) ₃ (CH ₂ ) ₂
Si (CH ₃ ) ₂ (CH ₂ ) ₉ SiCl ₃ , F (C
F ₂ ) ₈ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ S
iCl ₃ , CF ₃ COO (CH ₂ ) ₁₅ SiCl ₃ , CF
₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCl _{3 and} other trichlorosilane-based surfactants, for example, CF ₃ (CF
_{2) 7 (CH 2) 2} SiCl n (CH 3) 3-n, CF 3
(CF ₂ ) ₇ (CH ₂ ) ₂ SiCl _n (C
_{2 H 5) 3-n,} CF 3 CH 2 O (CH 2) 15 SiCl n
(CH ₃ ) _3-n , CF ₃ CH ₂ O (CH ₂ ) ₁₅ SiCl
_{n (C 2 H 5) 3} -n, CF 3 (CH 2) 2 Si (C
_{H 3) 2 (CH 2)} 15 SiCl n (CH 3) 3-n, F
(CF ₂ ) ₄ (CH ₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ )
₉ SiCl _n (C ₂ H ₅ ) _3-n , F (CF ₂ ) ₈ (CH
₂ ) ₂ Si (CH ₃ ) ₂ (CH ₂ ) ₉ SiCl _n (CH
₃ ) _3-n , CF ₃ COO (CH ₂ ) ₁₅ SiCl _n (CH
₃ ) _3-n , CF ₃ (CF ₂ ) ₅ (CH ₂ ) ₂ SiCl _n
(CH ₃ ) _3-n (where _{n in the} formula is 1 or 2) monochlorosilane- or dichlorosilane-based surfactants substituted with lower alkyl groups.

Among these, in particular, the trichlorosilane-based chemical adsorbent has a stronger chemical adsorption because chlorosilyl bonds other than chlorosilyl bonds bonded to hydrophilic groups form intermolecular bonds with adjacent chlorosilane groups and siloxane bonds. It becomes a film. For this reason, the trichlorosilane-based chemical adsorbent is a preferred material for the chemical adsorption film. Also, C
F ₃ (CF ₂ ) _n CH ₂ CH ₂ SiCl ₃ (where n is an integer and about 3 to 25 is the easiest to handle)
It is preferable because the chemical adsorption property and the functionality such as lubricity are balanced.

Further, if a vinyl group (C = C) or an acetylinyl group (ethynyl group) is incorporated in the fluorinated alkyl chain portion, crosslinking can be achieved by electron beam irradiation of about 5 megarads after formation of the chemisorption film. It is also possible to improve the hardness of the chemical adsorption film itself. The chlorosilane-based surfactant provided in the present invention is not limited to a straight chain as exemplified above, but may be a branched shape or a shape in which a terminal silicon is substituted with an alkyl fluoride group or a hydrocarbon group (for example, R, R ¹ , R ² and R ³ are each represented by a general formula R ₂ SiCl ₂ , R ₃ SiCl, R ¹
R ² SiCl ₂ or R ¹ R ² R ³ SiCl) may be used, but in order to increase the adsorption density, a straight chain is generally preferred.

Further, for example, SiCl ₄ ,
SiHCl ₃ , SiH ₂ Cl ₂ , Cl (SiCl ₂ O)
_n SiCl ₃ (where n is a natural number), SiCl _m (C
H ₃ ) _4-m , SiCl _m (C ₂ H ₅ ) _4-m (where m
Is an integer of 1 to 3), HSiCl _r (CH ₃ ) _3-r , HS
When a substance containing a plurality of chlorosilyl bonds such as iCl _r (C ₂ H ₅ ) _3-r (where 1 is 1 or 2) is chemically adsorbed and reacted with water, the chlorosilyl bonds on the surface become hydrophilic. The surface of the separation nail becomes hydrophilic. Among these substances containing a plurality of chlorosilyl groups, tetrachlorosilane (SiCl ₄ ) is preferable because it has a high reactivity and a small molecular weight and can provide a higher density silanol bond. A chlorosilane-based surfactant containing a fluorinated alkyl group can be chemically adsorbed on the inner layer film, and the density of the chemically adsorbed film thus obtained is further increased, so that the function of the separating property is further enhanced.

The method for forming a chemically adsorbed film containing a fluoroalkyl group through a siloxane bond on the surface of a separation nail used in the electrophotographic apparatus of the present invention comprises immersing the separation nail in a non-aqueous organic solvent. And a step of chemically adsorbing a chlorosilane-based surfactant on the surface to form a chemically adsorbed film containing an alkyl fluoride group via a siloxane bond.

The non-aqueous solvent used in the method of forming a chemically adsorbed film containing a fluorinated alkyl group through a siloxane bond on the surface of the separation nail of the present invention does not have active hydrogen that reacts with a chlorosilane-based surfactant. Any organic solvent may be used. Examples include 1,1-dichloro, 1-fluoroethane, 1,1-dichloro, 2,2,2 -trifluoroethane, 1,1-dichloro, 2,2,3,3,3-pentafluoropropane , 1,3-dichloro, 1,1,
Fluorinated solvents such as 2,2,3-heptafluoropropane, alkyltrifluoroamine, perfluorofuran and alkyl fluoride derivatives thereof, for example, hydrocarbon solvents such as hexane, octane, hexadecane and cyclohexane, for example, dibutyl ether, dibutyl ether Preferred are ether solvents such as benzyl ether and ester solvents such as methyl acetate, ethyl acetate, isopropyl acetate and amyl acetate.

Further, the function of the chemical adsorption film formed on the surface of the separation nail used in the electrophotographic apparatus of the present invention is sufficient even if only a single molecular chemical adsorption film is used. To form a single-molecule chemisorption film only, after chemical adsorption of a chlorosilane-based surfactant or a substance containing a plurality of chlorosilyl groups, it is only necessary to wash with a non-aqueous solvent without contacting with moisture. It can be easily performed without any process. In addition, it goes without saying that a monomolecular film may be accumulated in the chemisorption film. Thus, when the chemisorption film forms a monomolecular film,
The group exhibiting the imparted functionality is oriented and the density is improved, so that a higher function can be exhibited.

Further, a chemically adsorbed polymer film can be obtained by omitting the step of washing with a non-aqueous solution after the adsorption step. Next, the present invention will be described with reference to specific examples.

Example 1 A separation nail core having the shape shown in FIG. 2 was obtained from polyamideimide by cutting from a block or by injection molding. This molded product was treated with heptadecafluorodecyltrichlorosilane 1
0 ^-2 mol / liter cyclohexane solution at room temperature under a nitrogen atmosphere for 120 minutes, then washed heptadecafluorodecyltrichlorosilane unreacted cyclohexane is subsequently washed with thereafter pure water, fluorinated alkyl A chemisorbed monolayer via a siloxane bond containing a group was formed on the surface of the separation nail.

Example 2 The same separation claw as in Example 1 was immersed in a 1 wt% tetrachlorosilane solution [solvent: tri (n-nonafluorobutyl) amine] at room temperature under a nitrogen atmosphere for 60 minutes. The tetrachlorosilane of the reaction is washed with tri (n-nonafluorobutyl) amine, then washed with pure water, and the dried sample is used. As a chlorosilane-based surfactant containing an alkyl fluoride group, heptadecafluorodecyl is used. Using trichlorosilane, it was immersed in a tri (n-nonafluorobutyl) amine solution having a concentration of 10 ^-2 mol / l for 120 minutes under a nitrogen atmosphere at room temperature.
After washing with a nonafluorobutyl) amine solvent and then with pure water, a chemically adsorbed monomolecular film via a siloxane bond containing an alkyl fluoride group was formed on the surface of the separation nail.

[0022] were the same experiment by changing the heptadecafluorodecyltrichlorosilane in Example 3 Real Example 1 9- to (heptadecafluorodecyl dimethylsilyl) nonyl trichlorosilane.

Comparative Example 1 In Example 1, a polytetrafluoroethylene coating film was formed to a thickness of 10 μm by baking treatment instead of forming a chemical adsorption film.

The separation claws of Examples 1 to 3 and Comparative Example 1 were mounted on a fixing section of a commercially available electrophotographic apparatus, and were heated at 25 ° C. and 55%
An image was formed by repeating corona charging, image exposure, developing with a toner, transfer, fixing, and cleaning at RH 10,000 times. Table 1 shows the evaluation results of the quality of the image obtained after 10,000 times.

[0025]

[Table 1]

As is clear from Table 1, in the electrophotographic apparatus using the separation claw of the comparative example, the image quality deteriorated when used repeatedly and continuously. However, in the electrophotography apparatus using the separation claw of the present invention, the continuous image was repeatedly used. No deterioration in image quality was observed when used.

[0027]

As described above, the electrophotographic apparatus of the present invention is
Since the separation claw is provided with a chemisorption film containing a fluorinated alkyl group via a siloxane bond on the surface of the separation claw, the releasability is remarkably superior to the conventional one. As a result, high quality images can be obtained even if used continuously.
Moreover, since the chemisorption film is covalently bonded to the substrate surface,
High durability. Furthermore, the chemisorption film of the present invention
It's a very thin film in units of data or Angstroms
Without impairing the mechanical properties such as mechanical strength of the separation claw.
No. In addition, the chemisorption film of the present invention requires a baking process.
And not at the same time as the range of resin used increases
High quality separation without causing thermal degradation of resin during processing
Can be nails. Thus, the present invention is of great industrial value.

[Brief description of the drawings]

FIG. 1 is a conceptual cross-sectional view in which the surface of a separation claw used in the electrophotographic apparatus of the present invention is enlarged to a molecular level.

FIG. 2 is a sectional view of a separation claw used in the electrophotographic apparatus of the present invention.

[Explanation of symbols]

 Reference Signs List 1 separation claw 2 siloxane bond 3 chemisorption film 11 separation claw

Claims (2)

(57) [Claims] 1. An image forming apparatus comprising: an electrophotographic photosensitive member;
In an electrophotographic apparatus for obtaining a copied image by a process including development, transfer, fixing and cleaning steps, a substrate is provided on the surface of a separation claw used for offsetting paper.
Nanometer to angstrom thickness containing fluorinated alkyl groups through siloxane bond (covalent bond) with surface
An electrophotographic apparatus comprising a ROHM level chemical adsorption film. 2. The electrophotographic apparatus according to claim 1, wherein the chemisorption film is a monomolecular film or a polymer film.