JP2008116783A - Conductive roller for liquid developing system, manufacturing method for the same and image forming apparatus using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a conductive roller for a liquid developing system, the conductive roller having high production, having resistance to vegetable oil and small surface energy to the vegetable oil (large contact angle with the vegetable oil). <P>SOLUTION: The conductive roller for the liquid developing system has a surface covered with a surface protection layer composed of cured substance of fluorine-containing photo-setting composition, wherein the fluorine-containing photo-setting composition contains (meth)acrylate containing a fluorinated alkyl group and a photoinitiator, and the (meth)acrylate containing a fluorinated alkyl group has a functional group having a fluorinated alkyl group at the terminal and two or more (meth)acryloyl groups, and fluorine atom content in one molecule is ≥25 mass%, and molecular weight is 500 to 4,000. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a conductive roller used in an electrophotographic image forming apparatus such as a copying machine or a printer in which a liquid developer is used.

The surface of the conductive roller of the image forming apparatus in which the liquid developer is used is covered with a fluororesin layer in order to prevent contamination and extend the life of the conductive roller. A charging roller coated with a resin coating layer containing a cured product of a fluorine-containing ultraviolet curable poly (meth) acrylate resin having a fluorine content of 0.05 to 80% by mass and / or a fluorine-containing ultraviolet curable polyolefin resin. (For example, refer to Patent Document 1). The fluorine-containing ultraviolet curable resin needs to be cured in an irradiation intensity of 100 to 700 mW / cm ² and an integrated light amount of 200 to 3000 mJ / cm ² , and the manufacturing efficiency of the charging roller was not high.
A charging roller coated with a surface layer formed by applying a fluororesin solution and then dried (see, for example, Patent Document 2), and coated with a surface layer formed by applying a fluororesin solution and then drying. Another transfer roller has been studied (see, for example, Patent Document 3). When the charging roller and the transfer roller are used in an electrophotographic image forming apparatus in which a liquid developer is used, the contamination of these rollers cannot be sufficiently prevented, and the life of these rollers is short.
An anilox roller coated with an amorphous fluororesin layer whose main chain is perfluoropolyether has been studied (see, for example, Patent Document 4), a fixing roller coated with the amorphous fluororesin layer, and A pressure roller has been studied (see, for example, Patent Document 5). The amorphous fluororesin layer is formed by coating the amorphous fluororesin solution and leaving it at 50 to 250 ° C. for 15 minutes or more, and the production efficiency of these rollers is not high. Furthermore, the thickness of the amorphous fluororesin layer is 10 nm or less, and the lifetime of the amorphous fluororesin layer is not long.

Next, the carrier of the liquid developer will be described. Volatile hydrocarbon solvents are used as the carrier. An image forming apparatus using a liquid developer in which a volatile hydrocarbon solvent is used as a carrier has a carrier recovery device and is large. Nonvolatile silicone oil and liquid paraffin are also used as the carrier. When an image is formed on a transfer material by an image forming apparatus using a liquid developer in which silicone oil or liquid paraffin is used as a carrier, the carrier continues to exist on the transfer material. Therefore, recently, a liquid developer using vegetable oil as a carrier has been studied. However, the surface protective layer of the conductive roller of the image forming apparatus in which the liquid developer is used has not been studied.
JP 2005-352119 A JP 2006-163166 A Japanese Patent Laid-Open No. 2001-100549 JP 2002-278295 A JP 2002-268428 A

  An object of the present invention is to provide a conductive roller for a liquid development system that has high production efficiency, is resistant to vegetable oil, and has a small surface energy with respect to vegetable oil (a contact angle of vegetable oil is large).

  The present invention is a conductive roller for a liquid development system, the surface of which is coated with a surface protective layer made of a cured product of a fluorine-containing photocurable composition, the fluorine-containing photocurable composition containing a fluorinated alkyl group ( (Meth) acrylate and a photopolymerization initiator, and the fluorinated alkyl group-containing (meth) acrylate has a functional group having a fluorinated alkyl group at the terminal and two or more (meth) acryloyl groups, In addition, the conductive roller for a liquid development system has a fluorine atom content in one molecule of 25% by mass or more and a molecular weight of 500 to 4000.

〔式（１）中、Ｒは水素原子又は炭素数１〜４のアルキル基であり、Ｘはヘテロ原子を有していてもよいアルキレン鎖又は下記一般式（２）

〔式（２）中、Ｙは酸素原子又は硫黄原子であり、ｍとｎは同一でも異なっていてもよい１〜４の整数であり、Ｒｆ¹はフッ素化アルキル基である。〕
で表される連結基であり、Ｒｆはフッ素化アルキル基である。〕
で表される。 In a preferred embodiment of the present invention, in the conductive roller for a liquid developing system, the fluorinated alkyl group-containing (meth) acrylate is represented by the following general formula (1).

[In Formula (1), R is a hydrogen atom or a C1-C4 alkyl group, X is the alkylene chain which may have a hetero atom, or following General formula (2).

In [Equation (2), Y is an oxygen atom or a sulfur atom, m and n is an integer of 1 to 4 may be the same or different, Rf ¹ is a fluorinated alkyl group. ]
Rf is a fluorinated alkyl group. ]
It is represented by

In another preferred embodiment of the present invention, in the conductive roller for a liquid developing system, X in the general formula (1) is the following general formula (3).
_{- (CH 2) p -Z q} - (CH 2) r - (3)
In [Equation (3), Z is NR (R is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms.), An oxygen atom, a sulfur atom or NR-SO ₂ (R is C24 hydrogen or C P is an integer of 0 to 4, q is 0 or 1, r is an integer of 0 to 20, and 1 ≦ p + r ≦ 20. ] The alkylene chain represented by this.

In another preferred embodiment of the present invention, in the conductive roller for a liquid development system, X in the general formula (1) is a linking group represented by the general formula (2) [wherein Rf ¹ is C _n F _{2n + 1} (n is an integer of 1 to 20). ] Or an alkylene chain [However represented by the general formula (3), Z is NR (R is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms.), An oxygen atom, a sulfur atom or NR-SO ₂ (R Is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms), p is 1, q is 1, and r is an integer of 0 to 19. And Rf in the general formula (1) is the same as or different from Rf ¹ and C _n F _{2n + 1} (n is an integer of 1 to 20).

In another preferred embodiment of the present invention, in the conductive roller for a liquid development system, X in the general formula (1) is a linking group represented by the general formula (2) [provided that Y is a sulfur atom. , Rf ¹ has 4, 6 or 8 carbon atoms. ] Or an alkylene chain represented by the general formula (3) [wherein Z is NR (R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), sulfur atom or NR-SO ₂ (R is carbon number) 1 to 6 alkyl groups), and the carbon number n of Rf in the general formula (1) is 4, 6 or 8.

〔式（５）中、Ｙは酸素原子又は硫黄原子であり、ｍとｎは同一でも異なっていてもよい１〜４の整数であり、ＲｆとＲｆ¹は同一でも異なっていてもよいＣ_nＦ_2n+1（ｎは１〜２０の整数である。）である。〕で表される化合物（ａ２）とを、前記化合物（ａ１）１モルに対して、前記化合物（ａ２）を１．０〜（ｋ−２）モル〔ｋは前記化合物（ａ１）１分子中の平均（メタ）アクリロイル基数〕の割合でマイケル付加反応させて得られる化合物である。 In another preferred embodiment of the present invention, in the conductive roller for a liquid development system, the fluorinated alkyl group-containing (meth) acrylate has a compound (a1) having 3 or more (meth) acryloyl groups, and the following general formula: Formula (4)
_{Rf- (CH 2) r -Z-} H (4)
Wherein (4), r is an integer of 0 to 20, Rf is C _n F _{2n +} 1 _(n is an integer of 1 to 20.), Z is NR (R is a hydrogen atom or a carbon And an oxygen atom, a sulfur atom, or NR-SO ₂ (wherein R is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms). Or a compound represented by the following general formula (5)

In [Equation (5), Y is an oxygen atom or a sulfur atom, m and n is an integer of 1 to 4 may be the same or different, Rf and Rf ¹ good be the same or different C _n F _{2n + 1} (n is an integer of 1 to 20). The compound (a2) is represented by 1.0 to (k-2) mol [k is in one molecule of the compound (a1) with respect to 1 mol of the compound (a1). The average number of (meth) acryloyl groups] is obtained by a Michael addition reaction.

In another preferred embodiment of the present invention, in the conductive roller for a liquid development system, the compound (a2) is a compound represented by the general formula (4) [wherein Z is NR (R is a hydrogen atom or carbon An alkyl group having 1 to 6 carbon atoms), a sulfur atom or NR-SO ₂ (R is an alkyl group having 1 to 6 carbon atoms), and the carbon number n in Rf is 4, 6 or 8. Or a compound represented by the general formula (5) (wherein Y is a sulfur atom, and Rf and Rf ¹ have n, 4, 6 or 8 carbon atoms).

〔式（６）中、Ｒ¹は水酸基、炭素数１〜２４のアルキル基、炭素数１〜２４のアルキルカルボニルオキシ基、ＣＨ₂＝ＣＨＣＯ₂ＣＨ₂−、ＣＨ₂＝Ｃ（ＣＨ₃）ＣＯ₂ＣＨ₂−、繰り返し数が１以上で末端が水素原子、炭素数１〜１８のアルキル基で封鎖された（ポリ）オキシアルキレン基又は炭素数１〜１２のアルキロール基であり、Ｒ²は（メタ）アクリロイル基である。〕で表される化合物（ａ１−１）、下記一般式（７）

（式中、Ｒ²は（メタ）アクリロイル基であり、Ｒ³は水素原子又は炭素数１〜１８のアルキルカルボニル基であり、ｍは３〜６の整数であり、ｎは０〜３の整数であり、且つｍ＋ｎ＝６である。）で表される化合物（ａ１−２）、ウレタン（メタ）アクリレート（ａ１−３）、シアヌレート環含有トリ（メタ）アクリレート（ａ１−４）又はリン酸トリ（メタ）アクリレート（ａ１−５）である。 In another preferred embodiment of the present invention, in the conductive roller for a liquid development system, the compound (a1) having three or more (meth) acryloyl groups is represented by the following general formula (6).

Wherein (6), R ¹ represents a hydroxyl group, an alkyl group having 1 to 24 carbon atoms, alkylcarbonyloxy group having 1 to 24 carbon _{atoms, CH 2 = CHCO 2 CH 2} -, CH 2 = C (CH 3) CO ₂ CH ₂ — is a (poly) oxyalkylene group or an alkylol group having 1 to 12 carbon atoms which is blocked with a hydrogen atom, an alkyl group having 1 to 18 carbon atoms and having a repeating number of 1 or more, and R ² is (Meth) acryloyl group. ] Compound (a1-1) represented by the following general formula (7)

(In the formula, R ² is a (meth) acryloyl group, R ³ is a hydrogen atom or an alkylcarbonyl group having 1 to 18 carbon atoms, m is an integer of 3 to 6, and n is an integer of 0 to 3). And m + n = 6), urethane (meth) acrylate (a1-3), cyanurate ring-containing tri (meth) acrylate (a1-4) or triphosphate (Meth) acrylate (a1-5).

In another preferred embodiment of the present invention, in the conductive roller for a liquid development system, the compound (a1) having three or more (meth) acryloyl groups is represented by the general formula (6) [wherein R ¹ is carbon. A linear alkyl group having 1 to 4 carbon atoms, CH ₂ ═CHCO ₂ CH ₂ —, CH ₂ ═C (CH ₃ ) CO ₂ CH ₂ — or an alkylol group having 1 to 3 carbon atoms. A compound represented by the general formula (7): wherein R ³ is a hydrogen atom or an alkylcarbonyl group having 1 to 12 carbon atoms. Or a urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylate having two or more (meth) acryloyl groups with an isocyanate compound having an alicyclic structure.
In another preferred embodiment of the present invention, in the conductive roller for a liquid development system, the contact angle of soybean oil on the surface protective layer is 60 ° to 90 °.

The present invention relates to a method for producing a conductive roller for a liquid development system, the surface of which is coated with a surface protective layer made of a cured product of a fluorine-containing photocurable composition, and the substrate is coated with the fluorine-containing photocurable composition And then irradiating with 100 to 500 mJ / cm ² of ultraviolet rays to cure the fluorinated photocurable composition, and the fluorinated photocurable composition contains a fluorinated alkyl group (meth). An acrylate and a photopolymerization initiator are contained, and the fluorinated alkyl group-containing (meth) acrylate has a functional group having a fluorinated alkyl group at the terminal and two or more (meth) acryloyl groups, and 1 This is a method for producing a conductive roller for a liquid development system having a fluorine atom content in a molecule of 25% by mass or more and a molecular weight of 500 to 4000.

The present invention is an image forming apparatus in which the conductive roller for a liquid developing system and a liquid developer containing vegetable oil as a carrier are used.
The present invention is an image forming apparatus in which the surface of a charging roller, a developing roller, a transfer roller, a fixing roller, a photoreceptor and an intermediate transfer member is coated with the surface coating layer, and a liquid developer containing vegetable oil is used as a carrier. .
In a preferred embodiment of the present invention, the contact angle of soybean oil on the surface coating layer of the charging roller, developing roller, transfer roller, fixing roller, photoreceptor and intermediate transfer member of the image forming apparatus is 60 ° or more.

(Fluorine-containing photocurable composition)
The fluorine-containing photocurable composition of the present invention is a composition described in JP-A-2005-171238. The (meth) acryloyl group of the fluorinated alkyl group-containing (meth) acrylate of the present invention is a generic term for an acryloyl group and a methacryloyl group. The fluorinated alkyl group of the fluorinated alkyl group-containing (meth) acrylate of the present invention includes a perfluoroalkyl group in which all hydrogen atoms in the alkyl group are substituted with fluorine atoms, and a part of hydrogen in the alkyl group. Functional groups in which atoms are substituted with fluorine atoms (for example, HCF ₂ CF ₂ CF ₂ CF ₂ —) are generic names. The fluorinated alkyl group includes a fluorinated alkyl group containing an oxygen atom (for example, CF ₃ — (OCF ₂ CF ₂ ) ₂ —).
The fluorinated alkyl group of the fluorinated alkyl group-containing (meth) acrylate of the present invention is present at the end of the molecule and is not incorporated as part of the network when the fluorinated alkyl group-containing (meth) acrylate is crosslinked. The fluorinated alkyl group-containing (meth) acrylate of the present invention has two or more (meth) acryloyl groups that serve as crosslinking points at the time of crosslinking, and is strong when the fluorinated alkyl group-containing (meth) acrylate is crosslinked. A three-dimensional network structure is formed.

The fluorinated alkyl group-containing (meth) acrylate of the present invention contains 18% by mass or more of fluorine atoms. When the fluorine atom content is less than 18% by weight, the amount of fluorinated alkyl group-containing (meth) acrylate used is increased or the other fluorine atom content is high in order to develop oil repellency derived from fluorine atoms. It is necessary to use a reactive compound and / or a non-reactive compound in combination.
The molecular weight of the fluorinated alkyl group-containing (meth) acrylate of the present invention is 500 to 4000. When the molecular weight is larger than 4000, the crosslink density of the cured product of the fluorine-containing photocurable composition is decreased, and the mechanical properties of the cured product are decreased. On the other hand, when the molecular weight is less than 500, the fluorine atom content of the cured product is reduced, and the oil repellency derived from the fluorine atoms is not sufficiently expressed.

(Conductive roller)
A sectional view showing an example of the conductive roller of the present invention is shown in FIG. The conductive roller 1 of the present invention has a structure in which a conductive elastic layer 3 is provided on the outer periphery of a conductive shaft 2 and the surface of the conductive elastic layer 3 is covered with a surface coating layer 4. The conductive shaft 2 has a right columnar shape with a diameter of 5 to 20 mm, and both ends thereof are pivotally supported and are processed to be fitted with drive components. Specific examples of the metal used as the material of the conductive shaft 2 are plated steel, aluminum alloy, and stainless steel.

  The conductive elastic layer 3 is formed from a rubber composition containing a conductivity imparting agent, and the conductive elastic layer 3 has a JIS A hardness of 50 ° or less, preferably 30 ° or less. Specific examples of the rubber component contained in the rubber composition are acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPDM), chloroprene rubber (CR), epichlorohydrin rubber, urethane rubber, and silicone rubber. One type of rubber component may be used, and two or more types of rubber components may be used. Specific examples of the conductivity imparting agent are carbon black, titanium oxide, tin oxide, and zinc oxide. Since the dispersibility and the reinforcing function of carbon black with respect to the rubber component are excellent, a preferable conductivity imparting agent is carbon black. The resistance value of the rubber composition is prepared by the amount of the conductivity imparting agent blended in the rubber composition. A rubber component and a conductivity imparting agent are kneaded, and then the conductive shaft 2 and the rubber composition are integrally formed by a molding method such as extrusion molding or press molding, and the conductive elastic layer 3 is formed on the outer periphery of the conductive shaft 2. Provide. The rubber composition may contain additives such as a vulcanizing agent, a vulcanization accelerator, a softening agent, a filler, a processing aid, and a foaming agent.

When the rubber component is urethane rubber, a specific example of a method for forming the conductive elastic layer 3 is as follows. A polyurethane raw material, a cyclic amine catalyst and carbon black are kneaded to obtain a mixed solution, and then the mixed solution is injected into a mold provided with a conductive shaft coated with an adhesive and preheated, The curing reaction is performed at 130 to 160 ° C. for 15 to 25 minutes. Next, demolding is performed, and the conductive roller having the conductive elastic layer provided on the outer periphery of the conductive shaft is heated at 140 to 160 ° C. for 1 to 2 hours, and then cooled.
After the conductive elastic layer 3 is provided on the outer periphery of the conductive shaft 2, the conductive elastic layer 3 is subjected to cutting in order to adjust the dimensions and surface properties of the conductive elastic layer 3.

(Formation of a surface protective layer comprising a cured product of a fluorine-containing photocurable composition)
The conductive elastic layer 3 subjected to the cutting process is coated with a fluorine-containing photocurable composition. Specific examples of the coating apparatus include an air knife coater, a kiss roll coater, a metering bar coater, a gravure roll coater, a reverse roll coater, a dip coater, a die coater, a spray, and a combination thereof. Next, the fluorine-containing photocurable composition is polymerized and cured by light irradiation to obtain a conductive roller for liquid development coated with the surface protective layer 4 made of a cured product of the fluorine-containing photocurable composition. During light irradiation, heat can be used as an energy source. In this case, a polymerization initiator such as azobisisobutyronitrile, benzoin peroxide, or methyl ethyl ketone peroxide cobalt naphthenate can be used in combination.
The light source for light irradiation is not particularly limited. Specific examples of light sources include germicidal lamps, fluorescent lamps for ultraviolet rays, carbon arc, xenon lamps, high-pressure mercury lamps for copying, medium-pressure mercury lamps, high-pressure mercury lamps, ultra-high-pressure mercury lamps, electrodeless lamps, metal halide lamps, scanning electron accelerators, curtains Type electron accelerator.
The surface protective layer 4 has a thickness of 0.5 to 20 μm and a volume electric resistance of 10 ¹⁵ Ω · cm or less. The surface protective layer 4 may contain the conductivity imparting agent.

Specific examples of the conductive roller of the present invention are a charging roller, a developing roller, a transfer roller, and a fixing roller. The electric resistance of the charging roller and the developing roller of the present invention is set in the range of 10 ⁴ to 10 ¹⁰ Ω, preferably 10 ⁵ to 10 ⁸ Ω, from the viewpoint of obtaining a good image without damaging the photoreceptor. . The electric resistance of the transfer roller of the present invention is set in the range of 10 ⁷ to 10 ¹² Ω from the viewpoint of satisfactorily transferring the toner particles on the photoreceptor. The method for measuring the electrical resistance of the conductive roller 1 is as follows. The conductive roller 1 is horizontally applied to the metal plate, a load of 500 g is applied to both ends of the conductive shaft 2 in the vertical direction, and a DC voltage of 100 V is applied between the conductive shaft 2 and the metal plate. Measure electrical resistance.

(Liquid developer)
Specific examples of vegetable oil contained as a carrier in the liquid developer used in the image forming apparatus of the present invention include flaxseed oil, MO sunflower oil, rapeseed oil, divider oil, HOLL canola, safflower oil, olive oil, peanut oil, sesame oil, corn Oil, soybean oil, cottonseed oil, safflower oil. The vegetable oil may be one kind or a mixture of plural kinds.
Fatty acid triglycerides having a high proportion of unsaturated bonds such as oleic acid, linoleic acid, linolenic acid and the like cause oxidative polymerization. Therefore, the image forming apparatus of the present invention in which the liquid developer containing the fatty acid triglyceride having a high unsaturated bond ratio as a carrier does not need to have a fixing unit or has a simplified fixing unit. It only has to be.

  The liquid developer used in the image forming apparatus of the present invention may contain a charge control agent, a resin, a dispersant, an antioxidant and the like together with the pigment. Specific examples of the charge control agent include tetraethyl titanate, tetraisopropyl titanate, tetra-n-propyl titanate, tetra-n-butyl titanate, tetra-tert-butyl titanate, tetra-2-ethylhexyl titanate, tetraoctyl titanate, tetramethoxy titanium Titanium chelates such as titanyl acetyl acetate; isopropyl triisostearoyl titanate, isopropyl tridecylbenzenesulfonyl titanate, isopropyl tris (dioctyl pyrophosphate) titanate, tetraisopropyl bis (dioctyl phosphite) titanate, tetraoctyl bis (ditridecyl phosphite) Titanate, tetra (2,2-diallyloxydylmethyl-1-butyl) bis (di-tridecyl), bis (dio (Cutyl pyrophosphate) ethylene titanate, isopropyl trioctanoyl titanate, isopropyl dimethacrylisostearoyl titanate, isopropyl isostearoyl diacryl titanate, isopropyl tri (dioctyl phosphate) titanate, isopropyl tricumyl phenyl titanate, isopropyl tri (N-aminoethyl- Aminoethyl) titanate coupling agents such as titanate.

Specific examples of the resin include ethylene / vinyl acetate copolymer, polyester resin, styrene / acrylic resin, rosin modified resin, polyethylene, ethylene / acrylic acid copolymer, ethylene / maleic anhydride copolymer, polyvinylpyridine, polyvinylpyrrolidone. , Ethylene / methacrylic acid copolymer, and ethylene / acrylic acid ester copolymer. One or more resins selected from the above resins can be used.
An image forming apparatus according to the present invention is obtained by dispersing a mixture containing a pigment, vegetable oil, oleic acid, and the like treated with a resin and a basic polymer dispersant with a dispersing machine such as an attritor, a sand mill, a ball mill, or a vibration mill. The liquid developer used in 1) is obtained. The preferred primary particle diameter of the colored fine particles of the liquid developer used in the image forming apparatus of the present invention is 1 μm or less as the number average particle diameter.

The conductive roller for a liquid developing system of the present invention has the following excellent characteristics.
(1) Due to the oil repellency derived from fluorine atoms, the resistance and scratch resistance to the vegetable oil that is the carrier of the liquid developer are maintained for a long period of time, and the life of the conductive roller for the liquid development system of the present invention is long.
(2) The conductive roller for a liquid developing system of the present invention has a short manufacturing time and high productivity.
(3) The conductive roller for a liquid development system of the present invention has a high antifouling property.
(4) The liquid developer containing vegetable oil as a carrier is easily separated from the surface of the conductive roller, and the amount of liquid developer that is cleaned and discarded from the conductive roller is small, and the conductive roller for the liquid developing system of the present invention is used. The printing cost of the image forming apparatus is low.
(5) The developing roller of the present invention easily charges the liquid developer positively, the charging roller of the present invention easily charges the photoreceptor positively, and the transfer roller of the present invention improves transfer efficiency.
EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto.

(Synthesis of UV curable fluororesin)
(Synthesis Example 1)
A 500 ml four-necked flask equipped with a water separation tube was charged with 33.5 g of trimethylolpropane, 123.0 g of 3-perfluorooctylpropionic acid (manufactured by Tosoh F-Tech Co., Ltd.), 50 g of toluene, and 50 g of cyclohexane. Then, 2.5 g of concentrated sulfuric acid was added, and azeotropic dehydration was performed for 12 hours. After confirming that 4.5 g of water was produced, the mixture was once cooled to 25 ° C., 45.0 g of acrylic acid and 0.4 g of hydroquinone were added, and further azeotropic dehydration was performed while blowing air. After confirming that 9.0 g of water was produced, it was cooled to 25 ° C. 150 g of toluene was added to the reaction solution, neutralized and washed with 30 g of 25% aqueous sodium hydroxide solution, and further washed 3 times with 40 g of 20% by mass brine. Under reduced pressure, toluene and cyclohexane were distilled off to obtain 170 g of a slightly yellow liquid. The slightly yellow liquid was dissolved in 150 ml of toluene and purified by silica gel chromatography. Then, under reduced pressure, toluene was distilled off at a water bath temperature of 50 ° C. or lower while blowing oxygen, thereby obtaining a fluorinated alkyl group-containing acrylate (Compound A-1) represented by the following structural formula (i).

(Synthesis Example 2)
Add 15.7 g (0.03 mol) of dipentaerythritol hydroxypentaacrylate, 2 g of triethylamine, and 10 g of ethyl acetate to a 200 ml reaction flask, and gradually add 28.8 g (0.06 mol) of perfluorooctylethyl mercaptan with stirring. (The reaction temperature rose to 35 ° C). After the addition was completed, the mixture was further stirred at 50 ° C. for 3 hours. After completion of stirring, 60 g of ethyl acetate was added, and the organic layer was washed with 100 ml of 1N hydrochloric acid. Further, after washing twice with 100 ml of water, the organic layer was separated. The reaction solvent was distilled off under reduced pressure using an evaporator under a condition of 50 ° C. or lower, and further dried with a vacuum pump, whereby a fluorinated alkyl group-containing acrylate represented by the structural formula (ii) (Compound A-2) Got.

(Synthesis Example 3)
To a 200 ml reaction flask was added 21.2 g (0.05 mol) of tris (acryloxyethyl) isocyanurate (Aronix M-315 manufactured by Toa Gosei Co., Ltd.), 1.0 g of triethylamine, and 15 g of ethyl acetate. 19.0 g (0.05 mol) of fluorohexylethyl mercaptan was added dropwise with stirring (the reaction temperature rose to 35 ° C.). After the addition, the mixture was further stirred at 50 ° C. for 3 hours, and the ethyl acetate and triethylamine were distilled off under reduced pressure at 50 ° C. or lower, whereby a fluorinated alkyl group-containing acrylate represented by the following structural formula (iii) (Compound A-3) Got.

合成したフッ素化アルキル基含有アクリレートの性状を表１に示す。 (Synthesis Example 4)
In Synthesis Example 3, instead of 21.2 g (0.05 mol) of tris (acryloxyethyl) isocyanurate (Aronix M-315 manufactured by Toa Gosei Co., Ltd.), 15.1 g (0. 05 mol) in the same manner as in Synthesis Example 3 except that 24.0 g (0.05 mol) of perfluorooctylethyl mercaptan was used instead of 19.0 g (0.05 mol) of perfluorohexylethyl mercaptan. A fluorinated alkyl group-containing acrylate (Compound A-4) represented by the structural formula (iv) was obtained.

Table 1 shows the properties of the synthesized fluorinated alkyl group-containing acrylate.

(Formation of coating film made of fluorine compound)
Coating liquids of various fluorine compounds listed in Table 2 were applied on a 168 μm thick PET film by spin coating, and it was confirmed that a smooth and uniform surface coating film was formed. Then, heating or ultraviolet irradiation was performed to complete the coating film formation. If it did not solidify even when heated, it was used as it was as a measurement sample. Ultraviolet irradiation was performed using a UV irradiation apparatus (Isue Co., Ltd. Toscure 401).
A PET film on which a coating film was formed was cut into a 3 cm square and used as a measurement sample. The contact angle of soybean oil (Nisshin Oillio Group Co., Ltd.) on the measurement sample was measured using a contact angle measuring device (DropMaster DM700, Kyowa Interface Science Co., Ltd.) in an environment of 25 ° C. and humidity of 53%. did. The droplet amount at the time of measurement was set to 1 μL, and a 100 ms value and a 5900 ms value were obtained. Table 3 shows the measurement results.

試料１及び２はフルオロカーボンに、試料７〜１２はＴＨＦに溶解して塗布した。

Samples 1 and 2 were coated with fluorocarbon and samples 7-12 were dissolved in THF.

Composition (Samples 9-12) comprising a coating film formed from a fluororesin (Samples 1, 2 and 7), a coating film formed from a fluorinated surface modifier (Sample 8), and a fluorinated alkyl group-containing acrylate The coating film formed from 1 had excellent oil repellency.
So, soybean oil was dropped on each of the coating films formed from Samples 1, 2 and 7-12 to measure the contact angle, and then the surfaces of these samples were oiled with BEMCOT (Asahi Kasei Fibers Co., Ltd.). The process of measuring the contact angle was repeated 5 times after cleaning so that no film remained. The measured values for the fifth time are shown in Table 4.

フッ素化アルキル基含有アクリレートを含む組成物（試料９〜１２）から形成された塗膜は、清掃の影響をほとんど受けず、当該塗膜の撥油性は清掃によりほとんど低下しなかった。

The coating film formed from the composition containing the fluorinated alkyl group-containing acrylate (samples 9 to 12) was hardly affected by cleaning, and the oil repellency of the coating film was hardly deteriorated by cleaning.

(Adjustment of cyan liquid developer)
Pigment Blue 15: 3 35 parts by mass, polyester resin (Plastic DL-90 manufactured by Dainippon Ink & Chemicals, Inc.) and polymer dispersant (Ajinomoto Fine Techno Co., Ltd., Azisper PB-822) 8: 2 A cyan pigment was prepared by kneading and pulverizing with 65 parts by mass of the mixture mixed at a mass ratio of Next, 450 g of 3 mm diameter zirconia balls in a 500 ml capacity stainless steel container, 150 g of soybean oil (manufactured by Nisshin Oilio Group, triglyceride oleic acid component is 23.3 mass%), oleic acid (Kanto Chemical Co., Ltd.) 50 g, dispersant (Ajinomoto Fine Techno Co., Ltd., Azisper PA111) 0.11 g, cyan pigment 35 g, and using a commercially available stirrer Tornado SM type Probera stirring blade, dispersed and mixed for 24 hours at a rotation speed of 504 ppm. A cyan liquid developer as a colorant dispersion was prepared.

(Evaluation of adhesion of cyan colored fine particles to ITO electrode covered with coating film made of fluorine compound)
Coating film of sample 2 (soy oil contact angle 100 ms value is 57.9 °) on ITO electrode, coating film of sample 6 (soy oil contact angle 100 ms value of 47.9 °), coating film of sample 7 (large A soybean oil contact angle 100 ms value of 84.8 ° and a coating film of sample 12 (soy oil contact angle 100 ms value of 63.9 °) were formed to obtain an oil-repellent ITO electrode. Next, the adhesion of the cyan liquid developer to the oil-repellent ITO electrode at 25 ° C. was measured using an electrophoresis experimental apparatus shown in FIG.

  FIG. 2A is a perspective view illustrating a measurement cell, and FIG. 2B is a perspective view illustrating an electrode portion. In the measurement cell 5, an anode side electrode portion 7 and a cathode side electrode portion 8 are installed in a container 6 made of an electrically insulating member such as glass or synthetic resin. An anode terminal 9 provided on the anode side electrode portion 7 is connected to a power feeding anode side lead wire 10 coupled to a current supply device (not shown), and is provided on the cathode side electrode portion 8. A cathode-side lead wire 12 coupled to a current supply device (not shown) is connected to the cathode terminal 11. The anode-side electrode portion 7 and the cathode-side electrode portion 8 are provided with a holding member mounting groove 13 for holding both electrode portions at a predetermined interval at the upper portion thereof. Is held at a predetermined interval. A flow groove 14 is provided below the anode electrode portion 7 and the cathode electrode portion 8 so that the pigment dispersion can be smoothly supplied.

  Although the anode electrode portion is shown in FIG. 2B and described, the cathode electrode portion is also formed of the same structure and members. As the anode electrode portion 7, a molded body in which a projection 15 for anode engagement is provided on a resin having high oil resistance and solvent resistance such as polyacetal resin (POM) is used. An anode 16 is attached to the anode engaging protrusion 15 together with a spacer 17 made of an insulating member that keeps the distance from the counter electrode constant. The anode 16 is an electrode in which an ITO transparent conductive film 18 that does not elute by an applied current when a current is applied is formed on a transparent glass plate. By using an ITO transparent conductive film formed on a transparent glass plate, it is easy to optically observe and measure the pigment deposited on the anode removed from the anode electrode part after electrophoresis for a predetermined time. Can be performed.

  The oil-repellent ITO electrode is the cathode, the ITO electrode with nothing applied on the surface is the anode, a 300V DC voltage is applied to the electrophoresis experimental apparatus for 10 seconds, and the positively charged cyan colored fine particles are electrophoresed to obtain the oil-repellent ITO. Attached to the electrode. The ITO electrode was removed from the measurement cell, and then the cyan colored fine particles adhering to each electrode were transferred onto a transfer paper (J paper manufactured by Fuji Xerox Office Supply Co., Ltd.) to obtain a colored solid image. The density of the obtained colored solid image was measured as the reflection density using a reflection densitometer (model 520 type spectral densitometer manufactured by X-Rite) after being left for 1 day. The oil repellency (determined that the larger the contact angle, the higher the oil repellency function) was considered to be higher as the reflection density (OD value) of the colored solid image on the transfer paper was lower. The relationship between the measured reflection density (OD value) and the contact angle is shown in FIG. It was confirmed that the liquid developer using soybean oil as a carrier hardly adheres to a film having a contact angle of soybean oil of 60 ° or more.

(Example 1)
(Production of charging roller)
EPDM, vulcanizing agent, oil, foaming agent and carbon black are kneaded and extrusion molded, and then the molded body is vulcanized in a continuous vulcanizing tank using UHF and hot air in combination to form a hose with an inner diameter of 5 mm and an outer diameter of 12 mm. Obtained. On the other hand, 100 parts by mass of a polyether block amide elastomer (PAE 1200U manufactured by Ube Industries, Ltd.) and 15 parts by mass of carbon black (Ketjen Black EC manufactured by Lion Akzo Co., Ltd.) were mixed with a KCK kneader (Kay Kay Applied Technology Laboratory). Kneaded). Furthermore, 100 parts by mass of thermoplastic polyurethane for hot melt bonding (E780P128 manufactured by Nippon Miractran Co., Ltd.) and 25 parts by mass of carbon black (Ketjen Black EC manufactured by Lion Akzo Co., Ltd.) were mixed with KCK kneader Kneaded by a laboratory). Next, using two Brabender φ20 extruders (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the thermoplastic polyurethane composition is placed on the inside, from the crosshead having corrugated irregularities in the portion that regulates the outer peripheral surface of the outer layer. A multilayer hose was obtained by extrusion molding on the hose so that the ether block amide elastomer was on the outside. The multilayer hose was cut to obtain a multilayer hose having a length of 225 mm, and then a shaft (SUS301, φ6) having a length of 240 mm was inserted into the multilayer hose having a length of 225 mm. A charging roller having a conductive elastic layer having a thickness of 2 mm and a JIS A hardness of 40 °, wherein the multi-layer hose with the shaft inserted is heated at 120 ° C. for 15 minutes to shrink the multi-layer hose and the thermoplastic polyurethane layer and the foamed rubber layer are bonded. A substrate was obtained. The charging roller substrate was polished so that the surface roughness Rz was 2 μm. The 5900 ms value for the contact angle of soybean oil on the polished surface was 58 °.

The fluorine-containing ultraviolet curable composition of Sample 9 was dissolved in methyl cellosolve to prepare a coating solution having a solid content concentration of 5% by mass. Using a spray coating machine manufactured by Asahi Sunac Co., Ltd., the coating solution in which the fluorine-containing ultraviolet curable composition of Sample 9 was dissolved was applied to the charging roller substrate having a surface roughness Rz of 2 μm from the bottom to the top. The roller base was applied while rotating at 120 rpm. Thereafter, the same operation was repeated again. Next, while rotating the charging roller substrate coated with the fluorine-containing ultraviolet curable composition at 120 rpm using a cylindrical tube rotating drying ultraviolet irradiation device (NPT453 manufactured by Nippon Bunka Seiko Co., Ltd.), the irradiation amount is 160 mJ. A charging roller for a liquid developing system coated with a surface protective layer having a thickness of 1 μm was irradiated with UV light of / cm ² for 20 seconds. The 5900 ms value of the contact angle of soybean oil on the surface protective layer of the obtained charging roller was 69.0 °, and the work function was 5.71 eV.

  The method for measuring the work function of the conductive roller is as follows. The conductive roller is cut to a width of 1 to 1.5 cm, and cut in the horizontal direction along the ridgeline to obtain a measurement sample piece having the shape shown in FIG. As shown in FIG. 4 (b), the measurement sample piece is a surface analyzer (AC-2 type manufactured by Riken Keiki Co., Ltd.) so that the irradiation surface is parallel to the direction in which the measurement light is irradiated. Fix to the sample stage. Next, the measurement sample piece is irradiated with single-light excitation energy (photon energy) while scanning from low to high, and the normalized photoelectron yield is measured. At this time, the amount of irradiation light was 500 nW, the temperature was 25 ° C., and the relative humidity was 53%. The excitation energy at the inflection point of the graph drawn with the excitation energy on the horizontal axis and the normalized photoelectron yield on the vertical axis is the work function. The work function is an energy value at which photoelectron emission starts.

(Production roller development)
100 mass parts of terminal allylated polyoxypropylene polymer having a number average molecular weight of 8000 and molecular weight distribution of 2, 6.6 mass parts of polysiloxane-based curing agent (SiH number 0.36 mol / 100 g), 10 mass% isopropyl chloroplatinic acid 0.06 part by mass of an alcohol solution and 7 parts by mass of carbon black (Mitsubishi Chemical Co., Ltd. 3030B) were mixed and degassed under reduced pressure at 10 mmHg or less for 120 minutes. The obtained composition was coated around a shaft (SUS301, φ8) and cured in a mold at 120 ° C. for 30 minutes to obtain a developing roller substrate having a conductive elastic layer having a thickness of 6 mm and a JIS A hardness of 15 °. . The developing roller substrate was polished so that the surface roughness Rz was 3 μm. The 5900 ms value for the contact angle of soybean oil on the polished surface was 58 °.

The fluorine-containing ultraviolet curable composition of Sample 10 was dissolved in methyl cellosolve to prepare a coating solution having a solid content concentration of 5% by mass. Using a spray coating machine manufactured by Asahi Sunac Co., Ltd., the coating solution in which the fluorine-containing ultraviolet curable composition of Sample 10 was dissolved was developed from the bottom to the top of the developing roller base having a surface roughness Rz of 3 μm. The roller base was applied while rotating at 120 rpm. Thereafter, the same operation was repeated again. Next, while rotating the developing roller substrate coated with the fluorine-containing ultraviolet curable composition at 120 rpm using a cylindrical tube rotating drying ultraviolet irradiation device (NPT453 manufactured by Nippon Bunka Seiko Co., Ltd.), the irradiation amount is 160 mJ. A developing roller for a liquid developing system coated with a surface protective layer having a thickness of 1 μm was irradiated with UV light of / cm ² for 20 seconds. The contact angle of soybean oil on the surface protective layer of the developing roller thus obtained was 68.9 ° and the work function was 5.68 eV.

(Preparation of secondary transfer roller)
Epichlorohydrin rubber (ZEKRON G3100 manufactured by Nippon Zeon Co., Ltd.) 100 parts by mass NBR 27 parts by mass, carbon black 25 parts by mass, calcium carbonate 100 parts by mass, zinc oxide 5 parts by mass, surface treated sulfur 1 part by mass, vulcanization accelerator And a vulcanization aid were kneaded with an open roll to obtain a rubber composition. The rubber composition was extrusion molded, and then the molded body was vulcanized in a continuous vulcanization tank using both UHF and hot air to obtain a hose having an inner diameter of 5 mm and an outer diameter of 12 mm. On the other hand, 100 parts by mass of a polyether block amide elastomer (PAE 1200U manufactured by Ube Industries, Ltd.) and 15 parts by mass of carbon black (Ketjen Black EC manufactured by Lion Akzo Co., Ltd.) were mixed with a KCK kneader (Kay Kay Applied Technology Laboratory). Kneaded). Furthermore, 100 parts by mass of thermoplastic polyurethane for hot melt bonding (E780P128 manufactured by Nippon Miractran Co., Ltd.) and 25 parts by mass of carbon black (Ketjen Black EC manufactured by Lion Akzo Co., Ltd.) were mixed with KCK kneader Kneaded by a laboratory). Next, using two Brabender φ20 extruders (manufactured by Toyo Seiki Seisakusho Co., Ltd.), the thermoplastic polyurethane composition is placed on the inside, from the crosshead having corrugated irregularities in the portion that regulates the outer peripheral surface of the outer layer. A multilayer hose was obtained by extrusion molding on the hose so that the ether block amide elastomer was on the outside. The multilayer hose was cut to obtain a multilayer hose having a length of 225 mm, and then a shaft (SUS301, φ10) having a length of 240 mm was inserted into the multilayer hose having a length of 225 mm. The multi-layer hose with the shaft inserted is heated at 120 ° C. for 15 minutes to shrink the multi-layer hose, and the thermoplastic polyurethane layer and the rubber layer are bonded to each other. A roller substrate was obtained. The secondary transfer roller substrate was polished so that the surface roughness Rz was 2 μm. The 5900 ms value for the contact angle of soybean oil on the polished surface was 37 °.

The fluorine-containing ultraviolet curable composition of Sample 11 was dissolved in methyl cellosolve to prepare a coating solution having a solid content concentration of 5% by mass. Using a spray coating machine manufactured by Asahi Sunac Co., Ltd., the coating solution in which the fluorine-containing ultraviolet curable composition of Sample 11 was dissolved was applied from the bottom to the top of the secondary transfer roller substrate having a surface roughness Rz of 2 μm. The charging roller substrate was applied while rotating at 120 rpm. Thereafter, the same operation was repeated twice. Next, the secondary transfer roller substrate coated with the fluorine-containing ultraviolet curable composition was irradiated while rotating at 120 rpm using a cylindrical tube rotation drying ultraviolet irradiation device (NPT453 manufactured by Nippon Bunka Seiko Co., Ltd.). A secondary transfer roller for a liquid development system coated with a surface protective layer having a thickness of 1.5 μm was irradiated with ultraviolet rays having an amount of 160 mJ / cm ² for 20 seconds. The 5900 ms value of the contact angle of soybean oil on the surface protective layer of the obtained secondary transfer roller was 68.9 °, and the work function was 5.66 eV.

(Fixing roller production)
100 parts by mass of polydimethylsiloxane (degree of polymerization of about 5000) containing 0.15 mol% of a methylvinylsiloxane unit as a siloxane base polymer, 20 parts by mass of conductive carbon black (Denka Black HS-100 manufactured by Denki Kagaku Kogyo Co., Ltd.) 3 parts by mass of a solid solution of zinc oxide and tin oxide (Pastran 2100 manufactured by Mitsui Mining & Smelting Co., Ltd.) and 15 parts by mass of 2,5-dimethyl-2,5-di-t-butylperoxyhexane A composition was prepared. Next, an iron shaft having a diameter of 42 mm was coated with the silicone composition. Thereafter, the shaft coated with the silicone composition was heated in a mold at 170 ° C. for 10 minutes to perform press vulcanization, then heated at 200 ° C. for 4 hours to perform secondary vulcanization, and the thickness was 2 mm. A fixing roller substrate having a conductive elastic layer having a JIS A hardness of 25 ° was obtained. The fixing roller substrate was polished so that the surface roughness Rz was 3 μm. The 5900 ms value for the contact angle of soybean oil on the polished surface was 61 °.

The fluorine-containing ultraviolet curable composition of Sample 12 was dissolved in methyl cellosolve to prepare a coating solution having a solid content concentration of 5% by mass. Using a spray coating machine manufactured by Asahi Sunac Co., Ltd., the coating solution in which the fluorine-containing ultraviolet curable composition of Sample 12 was dissolved was applied from the bottom to the top of the secondary transfer roller substrate having a surface roughness Rz of 3 μm. The charging roller substrate was applied while rotating at 120 rpm. Thereafter, the same operation was repeated four times. Next, while rotating the fixing roller substrate coated with the fluorine-containing ultraviolet curable composition at 120 rpm using an ultraviolet irradiation apparatus for rotating and drying a cylindrical tube (NPT453 manufactured by Nippon Bunka Seiko Co., Ltd.), an irradiation amount of 160 mJ A fixing roller for a liquid developing system coated with a surface protective layer having a thickness of 2.5 μm was irradiated for 20 seconds with / cm ² ultraviolet rays. The contact angle of soybean oil on the surface protective layer of the obtained fixing roller was 68.8 ms, and the work function was 5.67 eV.
Table 5 shows the thicknesses of the surface protective layers of the charging roller, developing roller, secondary transfer roller and fixing roller, the work function of these rollers, and the 5900 ms value of the contact angle of soybean oil on the surface protective layer of these rollers. Show.

(Preparation of intermediate transfer belt)
A dispersion consisting of 30 parts by weight of a vinyl chloride-vinyl acetate copolymer, 10 parts by weight of conductive carbon black and 70 parts by weight of methyl alcohol was applied onto the aluminum layer of a polyethylene terephthalate film having a thickness of 130 μm on which aluminum was deposited, Next, the applied dispersion was dried to form an intermediate conductive layer having a thickness of 20 μm on the aluminum layer. Thereafter, 55 parts by weight of a nonionic aqueous urethane emulsion (solid content 62% by mass), 11.6 parts by mass of polytetrafluoroethylene emulsion (solid content 60% by mass), 25 parts by mass of conductive tin oxide, polytetrafluoroethylene fine particles ( A dispersion liquid comprising 34 parts by mass of a maximum particle size of 0.3 μm or less, 5 parts by weight of a polyethylene emulsion (solid content 35% by mass) and 20 parts by mass of ion-exchanged water is applied onto the intermediate conductive layer by a roll coating method. Subsequently, the coating film was dried to form a semiconductive surface layer having a thickness of 10 μm on the intermediate conductive layer, thereby preparing a laminate film. The laminate film was cut to a length of 540 mm, and then the end portions of the laminate film were aligned with the semiconductive surface layer facing up, and ultrasonic welding was performed to obtain a transfer belt. The volume resistance of the intermediate transfer belt is 2.5 × 10 ¹⁰ Ω · cm, the work function of the intermediate transfer belt is 5.37 eV, and the normalized photoelectron yield of the intermediate transfer belt when emission of photoelectrons starts is 6.90. Met.

A solution prepared by dissolving the fluorine-containing ultraviolet curable composition of Sample 11 in THF was spray-coated on the intermediate transfer belt, and then the intermediate transfer belt coated with the fluorine-containing ultraviolet curable composition was applied at 2.5 m / min. The intermediate transfer member (3) having a surface protective layer having a thickness of about 2 μm was obtained by irradiating with ultraviolet rays having an irradiation amount of 160 mJ / cm ² for 20 seconds. The work function of the intermediate transfer member (3) was 5.66 eV.

(Preparation of organic photoreceptor drum)
21 parts by mass of polycarbonate resin (TS-2020 manufactured by Teijin Chemicals Limited), 2 parts by mass of metal-free phthalocyanine (manufactured by Dainippon Ink & Chemicals, Inc.), 10 parts by mass of hydrazone compound (manufactured by Annan Co., Ltd.), toluene 180 Mass parts and 5 parts by mass of 3,5-dimethyl-3 ′, 5′-ditertiary butyl-4,4 ′ diphenoquinone were mixed in a paint conditioner for 10 hours to obtain a coating solution. Next, the coating solution was applied to a Φ40 aluminum base tube by a ring coating method to form a coating film, and then the coating film was dried to prepare an organic photoreceptor drum (film thickness 22 μm). The fluorine-containing ultraviolet curable composition of Sample 10 was dissolved in methyl cellosolve to prepare a coating solution having a solid content concentration of 5% by mass. Using a spray coating machine manufactured by Asahi Sunac Co., Ltd., the coating solution in which the fluorine-containing ultraviolet curable composition of Sample 10 is dissolved is rotated from the bottom of the organic photosensitive drum to 120 rpm while rotating the drum at 120 rpm. Applied. Thereafter, the same operation was repeated again. Next, while rotating the organic photosensitive drum coated with the fluorine-containing ultraviolet curable composition at 120 rpm using an ultraviolet irradiation device for rotating and drying a cylindrical tube (NPT453 manufactured by Nippon Bunka Seiko Co., Ltd.), the irradiation amount An organic photosensitive drum for a liquid development system was produced by irradiating with 160 mJ / cm ² of ultraviolet rays for 20 seconds and coated with a surface protective layer having a thickness of 1 μm.

Next, the semi-attenuated exposure amount and the light attenuation residual potential (potential after an exposure amount of 1 μJ / cm ² ) of the organic photosensitive drum were determined based on the light attenuation curve described below. A drum tester (PDT-2000LTM manufactured by QEA) was used, the process speed was set to 206 m / min, the applied voltage was set to 5.2 kV, the surface potential was set to 600 V, charging exposure was performed, and a light attenuation curve was drawn. The results are shown in Table 5. Table 5 also shows the 5900 ms value of the contact angle of rapeseed oil, sunflower oil, and safflower oil on the organophotoreceptor drum. Further, the semi-attenuated exposure amount and light decay residual potential of the organic photosensitive drum without the surface protective layer, the contact angle of rapeseed oil, sunflower oil, safflower oil on the organic photosensitive drum without the surface protective layer formed The 5900 ms value was also measured.

  The photosensitivity of an organic photoconductor drum made of a cured product of a fluorine-containing ultraviolet curable composition and coated with a surface protective layer having a thickness of 1 μm is slightly lower than the photosensitivity of an organic photoconductor drum without a surface protective layer. It was. However, the organic photoreceptor drum coated with the surface protective layer having a thickness of 1 μm has a light sensitivity with no practical problem. The contact angle of rapeseed oil, sunflower oil, safflower oil on the surface protective layer made of a cured product of the fluorine-containing ultraviolet curable composition is large on the surface protective layer made of the cured product of the fluorine-containing ultraviolet curable composition. It was almost the same as the contact angle of soybean oil.

(Preparation of magenta, yellow and black liquid developers)
Instead of Pigment Blue 15: 3 used in the preparation method of the cyan liquid developer (C), Pigment Red 57: 1 of magenta pigment, Pigment Yellow 74 of yellow pigment, carbon black of black pigment (particle diameter 40 nm, nitrogen adsorption specific surface area 55 m ² / g), a magenta liquid developer (M), a yellow liquid developer (Y), and a black liquid developer (K) were produced.

(Print test using a liquid development tandem printer)
Next, the liquid developer of each color prepared above was stored in the developing containers 21K, 21C, 21M, and 21Y of the tandem printer of the liquid developing system shown in FIG. 5, and a printing test was performed.
An outline of image formation by a liquid development type tandem printer will be described. Based on the input image signal, the laser light modulated by the exposure unit 22 is irradiated onto the charged photoreceptors 20K, 20C, 20M, and 20Y by the charging rollers 40K, 40C, 40M, and 40Y, respectively. An electrostatic latent image is formed on the photoconductors 20K, 20C, 20M, and 20Y. Next, the liquid developer of each color stored in the developing containers 21K, 21C, 21M, and 21Y is supplied to the photoconductors 20K, 20C, 20M, and 20Y via the developing rollers 30K, 30C, 30M, and 30Y, and the photoconductor 20K. , 20C, 20M, and 20Y, the electrostatic latent images formed are developed. The developed toner images of the respective colors on the photoconductors 20K, 20C, 20M, and 20Y are sequentially primary transferred onto the intermediate transfer belt 23 to form toner images. The intermediate transfer belt 23 is an endless belt, is stretched between a belt driving roller 25 and a tension roller 26, and is rotationally driven by the driving roller 25 while contacting the photoreceptors 20K, 20C, 20M, and 20Y. The toner image formed on the intermediate transfer belt 23 is secondarily transferred to a transfer material supplied from the cassette 29 at the secondary transfer position where the secondary transfer roller 24 is disposed. The transfer material that has passed the secondary transfer position is pressed against the fixing roller 27 by the pressure roller 28, and the toner image on the transfer material is fixed.

The printing test was performed under the following conditions.
Process speed: 206m / min
Applied voltage: 5.5 kV
Development bias: 350V
Toner layer thickness on developing rollers 30K, 30C, 30M, 30Y: 10 μm
Primary transfer voltage: 650V
Secondary transfer voltage: 1.5 kV
Transfer body: EP-L fine coating 81.4 gsm manufactured by Mitsubishi Paper Industries Co., Ltd.
Fixing roller 27 temperature: 110 ° C.
The charging roller for the liquid developing system was used as the charging rollers 40K, 40C, 40M, and 40Y. The developing roller for the liquid developing system was used as the developing rollers 30K, 30C, 30M, and 30Y. The intermediate transfer belt for the liquid development system, the secondary transfer roller for the liquid development system, and the fixing roller for the liquid development system were used as the intermediate transfer belt 23, the secondary transfer roller 24, and the fixing roller 27, respectively. The organic photoreceptor drum was used as the photoreceptors 20K, 20C, 20M, and 20Y. After printing on 1000 transfer materials, the photoconductors 20K, 20C, 20M, and 20Y (for four colors of the photoconductor), charging rollers 40K, 40C, 40M, and 40Y (for four colors of the charging roller), the intermediate transfer belt 23, The amount of liquid developer cleaned from each of the secondary transfer roller 24 and the fixing roller 27 was determined. In addition, a printing test was conducted by a tandem printer using a charging roller, a developing roller, an intermediate transfer belt, a secondary transfer roller, and a fixing roller on which no surface protective layer was formed. Table 7 shows the results of the printing test.

Liquid developer adhered to each of a charging roller, a developing roller, an intermediate transfer belt, a secondary transfer roller, and a fixing roller for a liquid development system, the surface of which is coated with a surface protective layer made of a cured product of a fluorine-containing photocurable composition The amount of the liquid developer was considerably smaller than the amount of the liquid developer adhering to each of the charging roller, the developing roller, the intermediate transfer belt, the secondary transfer roller, and the fixing roller for the liquid developing system in which the surface protective layer was not formed. Therefore, it is thought that the conclusion shown as following (1) and (2) can be drawn.
(1) The liquid developer is a non-developing material for a charging roller, a developing roller, an intermediate transfer belt, a secondary transfer roller, and a fixing roller for a liquid developing system coated with a surface protective layer made of a cured product of a fluorine-containing ultraviolet curable composition. Hard to adhere to the image area.
(2) An image forming apparatus using the charging roller, developing roller, intermediate transfer belt, secondary transfer roller and fixing roller has high transfer efficiency.

  The cyan liquid developer has a work function of 5.40 eV, the magenta liquid developer has a work function of 5.47 eV, the yellow liquid developer has a work function of 5.42 eV, and the black liquid developer has a work function of 5.45 eV. The work function of oleic acid used as a carrier for these liquid developers was 5.45 eV, and the work function of soybean oil was 5.50 eV. These work functions were measured as follows. First, a sample was placed in a recess of a measurement cell having a receiving recess having a diameter of 10 mm and a depth of 1 mm in the center of a stainless steel disk having a diameter of 13 mm and a height of 5 mm shown in FIGS. 6 (a) and (b). The surface of the sample was then leveled using a knife edge. Thereafter, the work function was measured by the method described above using the measurement cell filled with the sample. The work functions of the charging roller, the developing roller, the intermediate transfer belt, the secondary transfer roller and the fixing roller for the liquid developing system are larger than the work functions of the respective liquid developers. Therefore, when each liquid developer contacts the charging roller, developing roller, intermediate transfer belt, secondary transfer roller and fixing roller of the image forming apparatus of the present invention, each liquid developer can be positively charged, but negatively It is considered to have charging characteristics that cannot be charged. This charging characteristic is advantageous in an image forming method in which each liquid developer is subjected to primary transfer by applying a voltage from the photosensitive member to the intermediate transfer member, and then subjected to secondary transfer by applying a voltage from the intermediate transfer member to the transfer material. It is a characteristic.

Cross section of conductive roller The figure explaining the cell used for the adhesion measurement of the cyan coloring fine particles to the oil-repellent ITO electrode Correlation diagram of concentration and contact angle of cyan colored fine particles attached to oil-repellent ITO electrode The figure explaining the measuring method of the work function of an electroconductive roller. (A) is a perspective view which shows the shape of a measurement sample piece, (b) is a figure which shows a measurement state Schematic diagram of liquid development tandem printer The figure explaining the measurement cell used for the measurement of the work function of a liquid. (A) is a front view, (b) is a side view.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Conductive roller, 2 ... Shaft, 3 ... Conductive elastic layer, 4 ... Surface coating layer, 5 ... Measurement cell, 6 ... Container, 7 ... Anode side electrode part, 8 ... Cathode side electrode part, 9 ... Anode terminal, DESCRIPTION OF SYMBOLS 10 ... Anode side lead wire, 11 ... Cathode terminal, 12 ... Cathode side lead wire, 13 ... Holding member mounting groove, 14 ... Distribution groove, 15 ... Projection for anode engagement, 16 ... Anode, 17 ... Spacer, 18 ... Transparent conductive Film, 20K, 20C, 20M, 20Y ... photosensitive member, 21K, 21C, 21M, 21Y ... developing container, 22 ... exposure unit, 23 ... intermediate transfer belt, 24 ... secondary transfer roller, 25 ... belt drive roller, 26 ... Tension roller 27 ... Fixing roller 28 ... Pressure roller 29 ... Cassette 30K, 30C, 30M, 30Y ... Developing roller 40K, 40C, 40M, 40Y ... Charging roller

Claims (14)

A conductive roller for a liquid development system, the surface of which is coated with a surface protective layer made of a cured product of a fluorine-containing photocurable composition, the fluorine-containing photocurable composition comprising a fluorinated alkyl group-containing (meth) acrylate and A fluorinated alkyl group-containing (meth) acrylate containing a photopolymerization initiator, having a functional group having a fluorinated alkyl group at the terminal and two or more (meth) acryloyl groups, and in one molecule A conductive roller for a liquid development system having a fluorine atom content of 25% by mass or more and a molecular weight of 500 to 4000. Fluorinated alkyl group-containing (meth) acrylate is represented by the following general formula (1)

[In Formula (1), R is a hydrogen atom or a C1-C4 alkyl group, X is the alkylene chain which may have a hetero atom, or following General formula (2).

In [Equation (2), Y is an oxygen atom or a sulfur atom, m and n is an integer of 1 to 4 may be the same or different, Rf ¹ is a fluorinated alkyl group. ]
Rf is a fluorinated alkyl group. ]
The electroconductive roller for liquid development systems of Claim 1 represented by these. X in the general formula (1) is the following general formula (3)
_{- (CH 2) p -Z q} - (CH 2) r - (3)
In [Equation (3), Z is NR (R is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms.), An oxygen atom, a sulfur atom or NR-SO ₂ (R is C24 hydrogen or C P is an integer of 0 to 4, q is 0 or 1, r is an integer of 0 to 20, and 1 ≦ p + r ≦ 20. The conductive roller for a liquid development system according to claim 2, which is an alkylene chain represented by the formula: X in the general formula (1) is a linking group represented by the general formula (2) [wherein Rf ¹ is C _n F _{2n + 1} (n is an integer of 1 to 20). ] Or an alkylene chain [However represented by the general formula (3), Z is NR (R is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms.), An oxygen atom, a sulfur atom or NR-SO ₂ (R Is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms), p is 1, q is 1, and r is an integer of 0 to 19. A], and Rf in the general formula (1) is, Rf ¹ the same or different from C _n F _{2n +} 1 _(n is an integer from 1 to 20.) Is, according to claim 2 or 3 Conductive roller for liquid development system. X in the general formula (1) is a linking group represented by the general formula (2) [wherein Y is a sulfur atom and Rf ¹ has 4, 6 or 8 carbon atoms. ] Or an alkylene chain represented by the general formula (3) [wherein Z is NR (R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), sulfur atom or NR-SO ₂ (R is carbon number) 5. The conductive roller for a liquid development system according to claim 4, wherein the carbon number n of Rf in the general formula (1) is 4, 6 or 8. The compound (a1) in which the fluorinated alkyl group-containing (meth) acrylate has 3 or more (meth) acryloyl groups, and the following general formula (4)
_{Rf- (CH 2) r -Z-} H (4)
Wherein (4), r is an integer of 0 to 20, Rf is C _n F _{2n +} 1 _(n is an integer of 1 to 20.), Z is NR (R is a hydrogen atom or a carbon And an oxygen atom, a sulfur atom, or NR-SO ₂ (wherein R is a hydrogen atom or an alkyl group having 1 to 24 carbon atoms). Or a compound represented by the following general formula (5)

In [Equation (5), Y is an oxygen atom or a sulfur atom, m and n is an integer of 1 to 4 may be the same or different, Rf and Rf ¹ good be the same or different C _n F _{2n + 1} (n is an integer of 1 to 20). The compound (a2) is represented by 1.0 to (k-2) mol [k is in one molecule of the compound (a1) with respect to 1 mol of the compound (a1). The conductive roller for a liquid developing system according to claim 2, which is a compound obtained by a Michael addition reaction at a ratio of the average number of (meth) acryloyl groups]. Compound (a2) is a compound represented by Formula (4) above, wherein Z is NR (R is a hydrogen atom or an alkyl group having 1 to 6 carbon atoms), a sulfur atom or NR-SO ₂ ( R is an alkyl group having 1 to 6 carbon atoms, and the carbon number n in Rf is 4, 6 or 8.] or a compound represented by the general formula (5) (wherein Y is sulfur) The conductive roller for a liquid developing system according to claim 6, which is an atom, and the carbon number n in Rf and Rf ¹ is 4, 6 or 8. The compound (a1) having 3 or more (meth) acryloyl groups is represented by the following general formula (6)

Wherein (6), R ¹ represents a hydroxyl group, an alkyl group having 1 to 24 carbon atoms, alkylcarbonyloxy group having 1 to 24 carbon _{atoms, CH 2 = CHCO 2 CH 2} -, CH 2 = C (CH 3) CO ₂ CH ₂ — is a (poly) oxyalkylene group or an alkylol group having 1 to 12 carbon atoms which is blocked with a hydrogen atom, an alkyl group having 1 to 18 carbon atoms and having a repeating number of 1 or more, and R ² is (Meth) acryloyl group. ] Compound (a1-1) represented by the following general formula (7)

Wherein R ² is a (meth) acryloyl group, R ³ is a hydrogen atom or an alkylcarbonyl group having 1 to 18 carbon atoms, m is an integer of 3 to 6, and n is an integer of 0 to 3. And m + n = 6), urethane (meth) acrylate (a1-3), cyanurate ring-containing tri (meth) acrylate (a1-4) or triphosphate The conductive roller for a liquid development system according to claim 6 or 7, which is (meth) acrylate (a1-5). The compound (a1) having three or more (meth) acryloyl groups is represented by the general formula (6) [wherein R ¹ is a linear alkyl group having 1 to 4 carbon atoms, CH ₂ ═CHCO ₂ CH ₂ — CH ₂ = C (CH ₃ ) CO ₂ CH ₂ -or an alkylol group having 1 to 3 carbon atoms. A compound represented by the general formula (7): wherein R ³ is a hydrogen atom or an alkylcarbonyl group having 1 to 12 carbon atoms. Or a urethane (meth) acrylate obtained by reacting a hydroxyl group-containing (meth) acrylate having two or more (meth) acryloyl groups with an isocyanate compound having an alicyclic structure. Item 9. A conductive roller for a liquid development system according to any one of Items 6 to 8. The conductive roller for liquid development systems according to claim 1, wherein the contact angle of soybean oil on the surface protective layer is 60 ° to 90 °. A fluorine-containing photocurable composition is applied to a substrate, and then the fluorine-containing photocurable composition is cured by irradiating with 100 to 500 mJ / cm ² of ultraviolet rays. A method for producing a conductive roller for a liquid development system coated with a surface protective layer comprising a cured product of the above, wherein the fluorine-containing photocurable composition comprises a fluorinated alkyl group-containing (meth) acrylate and a photopolymerization initiator. And the fluorinated alkyl group-containing (meth) acrylate has a functional group having a fluorinated alkyl group at the terminal and two or more (meth) acryloyl groups, and has a fluorine atom content in one molecule. A method for producing a conductive roller for a liquid development system, which is 25% by mass or more and has a molecular weight of 500 to 4000. An image forming apparatus using the conductive roller for a liquid developing system according to claim 1 and a liquid developer containing vegetable oil as a carrier. An image forming apparatus in which the surface of a charging roller, a developing roller, a transfer roller, a fixing roller, a photoreceptor and an intermediate transfer body is coated with the surface coating layer according to claim 1 and a liquid developer containing vegetable oil is used as a carrier. . The image forming apparatus according to claim 13, wherein the contact angle of soybean oil on the surface coating layers of the charging roller, the developing roller, the transfer roller, the fixing roller, the photosensitive member, and the intermediate transfer member is 60 ° or more.

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