JP2011138052A - Composition for forming polysiloxane containing film and electrifying member - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a composition for forming a polysiloxane containing film having high dielectric characteristics after curing without causing troubles at coating (coating unevenness, stripes, and the like) even when forming a thick film while restraining opaqueness and phase separation. <P>SOLUTION: The composition for forming a polysiloxane containing film includes a photo polymerization initiator and a condensate of the hydrolyzable silane compounds and the hydrolyzable titanium compound obtained by hydrolysis in the presence of water and alcohol of a mixture of a hydrolyzable compound including 0.03 to 0.3 mol% of a predetermined hydrolyzable titanium compound with respect to two kinds of predetermined hydrolyzable silane compounds. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a composition for forming a polysiloxane-containing film, a charging member, a process cartridge, and an electrophotographic apparatus.

  Patent Document 1 synthesizes by an sol-gel method from an organosilicon compound having a functional group capable of reacting with a metal alkoxide at both ends or one end as an elastic layer or surface coating material of a fixing roller of an electrophotographic copying machine or the like and a metal alkoxide. The use of organic / inorganic hybrids.

JP 2001-222176 A

The present inventors have repeatedly studied the use of the organic / inorganic hybrid according to Patent Document 1 as a surface layer of a charging member of an electrophotographic apparatus. In the process, the present inventors studied to increase the relative dielectric constant of the surface layer by adding a high dielectric metal oxide component to the organic / inorganic hybrid. That is, with the recent increase in the speed of the electrophotographic image forming process, the contact time between the electrophotographic photosensitive member and the charging member has become relatively short. This is because the electrophotographic photosensitive member can be charged stably and reliably. This is a disadvantageous direction. In order to improve the charging performance of the charging member, it is effective to increase the relative dielectric constant of the surface layer. However, when synthesizing an organic / inorganic hybrid containing a highly dielectric metal oxide component using a hydrolyzable monomer, it has been found that there are the following problems.
(A) As shown in Table 1 below, the hydrolyzable compounds other than the hydrolyzable silane compound have a positive charge δ + in the central metal that is large in M (OR) _n where M is other than Si, and nucleophilicity. Very susceptible to attack. Therefore, the reaction rate is very fast, and it is difficult to control the reaction rate during the organic / inorganic hybrid reaction.

(B) When the alkoxide is hydrolyzed, the monomer structure after hydrolysis tends to become non-uniform due to a sharp drop in affinity with the solvent used.
(C) A structure in which condensation further proceeds to increase the molecular weight is likely to become non-uniform due to white turbidity, formation of precipitates, etc. if the affinity with the solvent used is insufficient. For example, as shown in Table 2 below, after hydrolysis and after condensation, δ is larger than before hydrolysis / condensation and the solubility decreases.

  Therefore, an object of the present invention is to form a polysiloxane-containing film in which white turbidity and phase separation in the state of the composition are suppressed and generation of coating unevenness and streaks on the coating film is suppressed during the coating film formation of the composition. Providing a composition for the use. Another object of the present invention is to provide a charging member that has a polysiloxane-containing film having a high dielectric constant as a surface layer, has excellent charging performance, and contributes to the formation of a high-quality electrophotographic image.

The composition for forming a polysiloxane-containing film according to the present invention is a composition for forming a polysiloxane-containing film comprising a condensate of a hydrolyzable silane compound and a hydrolyzable titanium compound and a photopolymerization initiator. In this condensate, the hydrolyzable titanium compound represented by the following formula (3) is converted to 0.03 to 0 with respect to the hydrolyzable silane compound represented by the following formula (1) and the following formula (2). A hydrolyzable compound mixture containing 3 mol% is hydrolyzed in the presence of water and alcohol:
Formula (1)
R ¹ —Z—Si— (OR ² ) ₃
(In the above formula (1), R ¹ is an organic group capable of cationic polymerization, Z is a divalent organic group, R ² is a saturated or unsaturated hydrocarbon group),
Formula (2)
(R ³ ) ₁ —Si— (OR ² ) ₃
(In the above formula (2), R ² represents a saturated or unsaturated hydrocarbon group, R ³ represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group),
Formula (3)
_{^{(R 3) x -Ti- (OR}} 2) 4-x
(In the above formula (3), x represents an integer of 0 to 3, R ² represents a saturated or unsaturated hydrocarbon group, R ³ represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. ).

  Further, the charging member according to the present invention is a charging member having at least a support, a conductive elastic layer, and a surface layer on the outer periphery of the support, wherein the surface layer is a photocuring of the coating film of the composition. It is characterized by including a film. Furthermore, a process cartridge according to the present invention includes the charging member. Furthermore, an electrophotographic apparatus according to the present invention is characterized by comprising the charging member. Furthermore, the method for producing a composition for forming a polysiloxane-containing film according to the present invention is a method for producing the composition, comprising: (i) a water solution represented by the formula (1) and the formula (2). A mixture of a hydrolyzable compound containing the hydrolyzable titanium compound represented by the formula (3) at a ratio of 0.03 to 0.3 mol% with respect to the decomposable silane compound in the presence of water and alcohol. Hydrolyzing to prepare a condensate of the hydrolyzable silane compound and the hydrolyzable titanium compound, and (ii) mixing the condensate and a photopolymerization initiator. It is characterized by that.

  ADVANTAGE OF THE INVENTION According to this invention, the composition for forming uniform polysiloxane containing film | membrane which suppressed the white turbidity and phase-separation state by excessive reaction of a hydrolyzable titanium compound, and the property was stable can be obtained. Therefore, generation | occurrence | production of the coating nonuniformity to the coating film of this composition, a stripe, etc. can be suppressed. Further, according to the present invention, when the coating film is photocured, it can have high dielectric properties.

It is a figure which shows an example of a structure of the charging member of this invention. 1 is a diagram illustrating an example of a schematic configuration of an electrophotographic apparatus having a charging member of the present invention.

[Composition for forming polysiloxane-containing film]
The composition for forming a polysiloxane-containing film according to the present invention includes a condensate of a hydrolyzable silane compound and a hydrolyzable titanium compound and a photopolymerization initiator. And this condensate is a hydrolyzable titanium compound shown by the following formula (3) with respect to the hydrolyzable silane compound shown by the following formula (1) and the following formula (2). It is obtained by hydrolyzing a mixture of hydrolyzable compounds containing 3 mol% in the presence of water and alcohol.

Formula (1)
R ¹ —Z—Si— (OR ² ) ₃
(In the above formula (1), R ¹ is an organic group capable of cationic polymerization, Z is a divalent organic group, R ² is a saturated or unsaturated hydrocarbon group),
Formula (2)
(R ³ ) ₁ —Si— (OR ² ) ₃
(In the above formula (2), R ² represents a saturated or unsaturated hydrocarbon group, R ³ represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group),
Formula (3)
_{^{(R 3) x -Ti- (OR}} 2) 4-x
(In the above formula (3), x represents an integer of 0 to 3, R ² represents a saturated or unsaturated hydrocarbon group, R ³ represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. ).

<Hydrolysable silane compound (A)>
The cationically polymerizable group of R ^{1 in} the hydrolyzable silane compound represented by the formula (1) (hereinafter referred to as hydrolyzable silane compound (A)) is a cationic polymerization that generates an oxyalkylene group by cleavage. Means possible organic groups. For example, a cyclic ether group such as an epoxy group or an oxetane group, a vinyl ether group, or the like can be given. Among these, an epoxy group is preferable from the viewpoints of availability and reaction control.

  Examples of the divalent organic group represented by Z in the formula (1) include an alkylene group and an arylene group. Among these, a C1-C6 alkylene group is preferable and an ethylene group is more preferable.

Examples of the saturated or unsaturated hydrocarbon group represented by R ² in the formula (1) include an alkyl group, an alkenyl group, and an aryl group. Among these, a linear or branched alkyl group having 1 to 4 carbon atoms, a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and a t-butyl group are preferable. The hydrolyzable silane compound (A) contains three — (OR ² ) groups, but each group may be different.

Specific examples of the hydrolyzable silane compound (A) are shown below.
(A-1): Glycidoxypropyltrimethoxysilane (GPTMS)
(A-2): Glycidoxypropyltriethoxysilane (GPTES)
(A-3): Epoxycyclohexylethyltrimethoxysilane (A-4): Epoxycyclohexylethyltriethoxysilane.

  Among these, (A-2) GPTES is preferable. These may use 1 type and may use 2 or more types together.

<Hydrolyzable silane compound (B)>
In the hydrolyzable silane compound represented by the formula (2) (hereinafter referred to as hydrolyzable silane compound (B)), R ³ is a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. is there. As said alkyl group, a C1-C21 linear alkyl group is preferable, and a C6-C10 linear alkyl group is more preferable. Examples of the aryl group include a phenyl group. A phenyl group is mentioned as a substituent of the said alkyl group or an aryl group. Incidentally, R ² is the same as R ² of hydrolyzable compounds (A).

Specific examples of the hydrolyzable silane compound (B) are shown below.
(B-1): Methyltrimethoxysilane (B-2): Methyltriethoxysilane (B-3): Methyltripropoxysilane (B-4): Ethyltrimethoxysilane (B-5): Ethyltriethoxysilane (B-6): ethyltripropoxysilane (B-7): propyltrimethoxysilane (B-8): propyltriethoxysilane (B-9): propyltripropoxysilane (B-10): hexyltrimethoxysilane (HeTMS)
(B-11): Hexyltriethoxysilane (B-12): Hexyltripropoxysilane (B-13): Decyltrimethoxysilane (B-14): Decyltriethoxysilane (B-15): Decyltripropoxysilane (B-16): Phenyltrimethoxysilane (B-17): Phenyltriethoxysilane (PhTES)
(B-18): Phenyltripropoxysilane.

Among these, (B-10) HeTMS is preferable. These may use 1 type and may use 2 or more types together. In addition, when using 2 types of said hydrolysable silane compounds (B) together, R < ³ > is a hydrolysable silane compound (B) which is a C6-C10 linear alkyl group, and R < ³ > is a phenyl group. It is more preferable to combine the hydrolyzable silane compound (B). Thereby, even if the monomer structure is changed by hydrolysis / condensation and reaction, the compatibility with the solvent is improved.

<Hydrolysable titanium compound (C)>
Formula (3) hydrolyzable titanium compound represented by (hereinafter, to hydrolyzable titanium compound (C)) R ² and R ³ in the, R ² and R of the hydrolyzable silane compound (B) ^Same as ³ . Specific examples of the hydrolyzable titanium compound (C) are shown below.
(C-1): Titanium methoxide (C-2): Titanium ethoxide (C-3): Titanium n-propoxide (C-4): Titanium i-propoxide (C-5): Titanium n-butoxide (C-6): Titanium t-butoxide (C-7): Methyl titanium triisopropoxide (C-8): Phenyl titanium triisopropoxide.

  Among these, (C-4) titanium i-propoxide is preferable. These may use 1 type and may use 2 or more types together.

<Alcohol (E)>
The alcohol (hereinafter referred to as alcohol (E)) is preferably a mixed liquid of a primary alcohol and a secondary alcohol or a mixed liquid of a primary alcohol and a tertiary alcohol. This is because the mixed liquid as described above is excellent in compatibility with both the monomer before condensation of (A), (B) and (C) and the condensate. That is, the SP value of methanol is 14.5, while the SP values of (A), (B), and (C) are very far from about 8.5 to 9.0. On the other hand, since only the secondary alcohol and the tertiary alcohol are close to the SP value of the monomer structure before the condensation, (A), (B) and (C) are changed to (C) / ((A) + ( B)) The step of adjusting to ≦ 0.3 has good solubility. However, the SP value estimated from the structure after the condensation is separated. Therefore, in consideration of the chemical structure of the monomer before / after the condensation, the chemical structure of the synthesized product, and the compatibility of the solvent used, a mixed solution of the primary alcohol and the secondary alcohol, or the primary alcohol and the primary alcohol It is preferable to use a mixed solution with a tertiary alcohol as the alcohol (E). In particular, a combination of methanol / 2-butanol and ethanol / 2-butanol is preferable.

<Blending amount>
The mixture of the hydrolyzable compound is 0.03 to 0.3 mol%, preferably 0.1 to 0.3 mol% of the hydrolyzable titanium compound (C) with respect to the hydrolyzable silane compounds (A) and (B). It is contained at a ratio of 0.2 mol%. If the amount is less than 0.03 mol%, the formation of a high dielectric is insufficient. If the amount exceeds 0.3 mol%, the condensation of the component (C) proceeds rapidly and fine particles are easily formed, which may cause precipitation.

  The molar ratio of (A) and (B) contained in the hydrolyzable compound mixture is such that (A) / ((A) + (B)) is 0.10 to 0.85, in particular 0. .35 to 0.70 is preferable. By setting the molar ratio of (A) and (B) within the above range, the reactivity with (C) or the solubility with the solvent used is improved, and the clouding of the composition can be more effectively suppressed. it can.

  The amount of water (hereinafter referred to as water (D)) for hydrolyzing the hydrolyzable compound is the total number of moles of the substituents (A), (B) and (C) to be hydrolyzed ((A ) + (B) + (C)), 0.4 ≦ (D) / ((A) + (B) + (C)) ≦ 3.0, in particular 0.6 ≦ (D) / It is preferable that ((A) + (B) + (C)) ≦ 2.0. By setting the amount of water within the above numerical range, condensation is sufficient, and unreacted monomers are difficult to remain. Moreover, it can make it difficult to produce the cloudiness and precipitation of a composition by the progress of condensation too early.

<Mixed>
As a method of mixing the above (A) to (E), a mixture of a hydrolyzable compound containing (A), (B) and (C) and (E) are mixed, and then the mixed solution is mixed. The method of dropping and mixing (D) while stirring is preferred from the viewpoint of uniform synthesis. The mixing temperature may be room temperature.

<Hydrolysis>
Next, the mixed solution of (A) to (E) is heated to reflux to hydrolyze the (A), (B) and (C) to prepare a condensate. Heating reflux is preferably performed at 100 to 120 ° C. while stirring the mixed solution. The heating reflux time is preferably 1 to 5 hours.

<Photopolymerization initiator (F)>
The photopolymerization initiator (hereinafter referred to as photopolymerization initiator (F)) preferably contains a cationic polymerization initiator. For example, an epoxy group shows high reactivity with respect to an onium salt of a Lewis acid activated by active energy rays. Therefore, when R ^{1 of the} hydrolyzable silane compound (A) is an epoxy group, it is preferable to use an onium salt of Lewis acid as the cationic polymerization initiator. Examples of other cationic polymerization initiators include borate salts, compounds having an imide structure, compounds having a triazine structure, azo compounds, and peroxides. Among various cationic polymerization initiators, aromatic sulfonium salts and aromatic iodonium salts are preferable from the viewpoints of sensitivity, stability, and reactivity. In particular, bis (4-tert-butylphenyl) iodonium salt and a compound having a structure represented by the following formula (4) (trade name: “ADEKA OPTMER SP150”, manufactured by ADEKA Corporation) are preferable. A compound having a structure represented by the following formula (5) (trade name: “Irgacure 261”, manufactured by Ciba Specialty Chemicals) is preferable.

  Moreover, the addition amount of the said photoinitiator (F) is 1.0-5.0 mass parts with respect to 100 mass parts of said condensates, Especially 2.0-4.0 mass parts is preferable. By making the addition amount of a photoinitiator into the said range, it can fully harden with the ultraviolet-ray of the coating film of a composition, and a problem does not arise easily in the solubility to a composition. In addition, in order to adjust the density | concentration of the composition for polysiloxane containing film formation after adding the said photoinitiator (F), you may add a solvent etc. suitably.

[Charging member]
The charging member according to the present invention is a charging member having at least a support and a conductive elastic layer and a surface layer on the outer periphery of the support. The surface layer is used for forming the polysiloxane-containing film according to the present invention. A photocured film of a coating film of the composition. The basic configuration of the charging member according to the present invention is a configuration including a support, a conductive elastic layer, and a surface layer. For such a basic configuration, another layer may be provided between at least one of the support and the elastic layer and between the elastic layer and the surface layer. In the charging roller according to the present invention shown in FIG. 1, a conductive elastic layer 102 is formed on the outer periphery of a support 101, and a surface layer 103 is formed on the outer periphery of the conductive elastic layer 102.

<Support>
Examples of the support of the charging member include a metallic (made of alloy) support made of iron, copper, stainless steel, aluminum, an aluminum alloy, or nickel.

<Elastic layer>
As the conductive elastic layer, one or more of rubber, thermoplastic elastomer and the like can be used. Examples of the rubber include the following. Urethane rubber, silicone rubber, butadiene rubber, isoprene rubber, chloroprene rubber, styrene-butadiene rubber, ethylene-propylene rubber, polynorbornene rubber, styrene-butadiene-styrene rubber, acrylonitrile rubber, epichlorohydrin rubber and alkyl ether rubber.

  Examples of the thermoplastic elastomer include styrene elastomers and olefin elastomers. Examples of commercially available styrene-based elastomers include “Lavalon” (trade name) manufactured by Mitsubishi Chemical Corporation, and “Septon Compound” (trade name) manufactured by Kuraray Co., Ltd. The following are mentioned as a commercial item of an olefin type elastomer. “Thermorun” (trade name) manufactured by Mitsubishi Chemical Corporation, “Miralastomer” (trade name) manufactured by Mitsui Petrochemical Industries, Ltd., “Sumitomo TPE” (trade name) manufactured by Sumitomo Chemical Industries, Ltd. "Santplane" (trade name) manufactured by Advanced Elastomer Systems.

The elastic layer has a predetermined conductivity by containing a conductive agent. A preferable range of the electric resistance of the elastic layer is 10 ² to 10 ⁸ Ω, particularly 10 ³ to 10 ⁶ Ω. Examples of the conductive agent include a cationic surfactant, an anionic surfactant, an amphoteric surfactant, an antistatic agent, and an electrolyte.

  Examples of the cationic surfactant include the following. Quaternary ammonium salts such as lauryltrimethylammonium, stearyltrimethylammonium, octadodecyltrimethylammonium, dodecyltrimethylammonium, hexadecyltrimethylammonium, and modified fatty acid dimethylethylammonium. Examples of the quaternary ammonium salt include the following. Perchlorate, chlorate, borofluoride, ethosulphate salt and benzyl halide salt (such as benzyl bromide and benzyl chloride).

  Examples of the anionic surfactant include aliphatic sulfonate, higher alcohol sulfate ester salt, higher alcohol ethylene oxide addition sulfate ester salt, higher alcohol phosphate ester salt and higher alcohol ethylene oxide addition phosphate ester salt.

Examples of the antistatic agent include nonionic antistatic agents such as higher alcohol ethylene oxide, polyethylene glycol fatty acid ester and polyhydric alcohol fatty acid ester. Examples of the electrolyte include salts of metals (Li, Na, K, etc.) belonging to Group 1 of the periodic table. Specific examples of the metal salt of Group 1 of the periodic table include LiCF ₃ SO ₃ , NaClO ₄ , LiAsF ₆ , LiBF ₄ , NaSCN, KSCN, and NaCl.

Active hydrogen capable of reacting with salts (Ca (ClO ₄ ) ₂ ) of group 2 metals (Ca, Ba), antistatic agents derived therefrom, and isocyanates (primary amino groups and secondary amino groups) from the periodic table Those having at least one group (hydroxyl group, carboxyl group) may be used for the conductive agent. Furthermore, these and polyhydric alcohols (1,4-butanediol, ethylene glycol, polyethylene glycol, propylene glycol, polyethylene glycol) or their derivatives, monools (ethylene glycol monomethyl ether, ethylene glycol monoethyl ether) A complex with can also be used as a conductive agent. Furthermore, conductive carbon black, graphite, metal oxides (tin oxide, titanium oxide and zinc oxide), metals (nickel, copper, silver and germanium), conductive polymers (polyaniline, polypyrrole and polyacetylene) are also used as conductive agents. Can be used.

  Moreover, you may add an inorganic or organic filler and a crosslinking agent to an elastic layer. Examples of the filler include silica (white carbon), calcium carbonate, magnesium carbonate, clay, talc, zeolite, alumina, barium sulfate and aluminum sulfate. Examples of the crosslinking agent include sulfur, a peroxide, a crosslinking aid, a crosslinking accelerator, a crosslinking acceleration aid, and a crosslinking retarder.

  The hardness of the conductive elastic layer is preferably 70 degrees or more with Asker C from the viewpoint of suppressing the deformation of the charging member when the charging member and the photosensitive drum as the member to be charged are brought into contact with each other. More preferably, it is not less than 90 degrees and not more than 90 degrees.

<Surface layer>
The surface layer of the charging member according to the present invention includes a photocured film of a coating film of the composition for forming a polysiloxane-containing film according to the present invention. In addition, the elastic modulus of the surface layer of the charging member is preferably 2000 MPa or less from the viewpoint of sufficiently exerting the function of the conductive elastic layer provided in order to ensure a sufficient contact nip with the photosensitive drum. On the other hand, in general, the crosslinking density tends to decrease as the elastic modulus of the surface layer decreases. For this reason, since the low molecular weight component bleed out on the surface of the charging member may contaminate the surface of the photosensitive drum, the elastic modulus of the surface layer of the charging member is preferably 100 MPa or more.

  In addition, the thicker the surface layer, the greater the effect of suppressing the bleed out of the low molecular weight component, but the charging ability is conversely reduced. Specifically, the layer thickness of the surface layer is preferably 0.01 to 0.50 μm, and more preferably 0.02 to 0.20 μm.

Further, the volume resistivity of the surface layer is preferably 10 ¹⁰ to 10 ¹⁶ Ω · cm. The charging member can be appropriately determined in consideration of the film thickness. In addition, from the viewpoint of suppressing sticking of toner and external additives to the surface of the charging member, the surface roughness (Rz) of the charging member shall be 10 μm or less, particularly 7 μm or less, more preferably 5 μm or less according to JIS94. Is preferred.

[Method of manufacturing charging member]
<Conductive elastic member>
As a method for producing a charging member according to the present invention, first, a kneaded product is obtained by kneading the conductive elastic layer material. Next, a thermosetting adhesive is applied to the support and dried.

  Using a crosshead extruder, the kneaded product is extruded into a cylindrical shape so as to cover the support while extruding the support that has been coated with the thermosetting adhesive and dried. Take the support edge while receiving it and cut the edge. Next, vulcanization is performed in a continuous heating furnace. A continuous heating furnace with two zones with different temperature settings is used. Rapid rise in vulcanization temperature tends to cause voids. This is presumed to be because volatile by-products such as a vulcanization accelerator due to the vulcanization reaction are gasified and confined in a state in which the gas is difficult to escape during the curing by rubber vulcanization. For this reason, bubbles are generated around the support or near the extrusion surface, and when this is polished, it becomes concave and causes image defects. Therefore, it is preferable to perform vulcanization in the second zone after sufficiently removing the gas component by providing two curing zones and maintaining the first zone below the vulcanization temperature. The temperature and time of the first zone and the second zone can be set as appropriate. A conductive elastic member can be obtained by polishing the surface of the conductive elastic layer after vulcanization.

<Charging member>
Next, the composition for forming a polysiloxane-containing film according to the present invention (hereinafter sometimes simply referred to as a composition) is prepared to have an appropriate viscosity and applied onto the conductive elastic member. In preparing the viscosity of the composition, an appropriate solvent considering volatility may be used in addition to the solvent used for the synthesis in order to improve the coating property. Suitable solvents include ethyl acetate, methyl ethyl ketone, or a mixture thereof. Moreover, when apply | coating a composition on a conductive elastic member, application | coating using a roll coater, immersion application | coating, ring application | coating, etc. are employable.

  Next, an active energy ray is irradiated to the composition apply | coated on the electroconductive elastic member. Then, the cationically polymerizable group contained in the composition can be cleaved and crosslinked, and cured by crosslinking. As the active energy ray, ultraviolet rays are preferable. The conductive elastic layer of the conductive elastic member may expand due to heat generated during the irradiation of the active energy ray, and then contract by cooling. For this reason, if the surface layer does not sufficiently follow this expansion / contraction, the surface layer may have many wrinkles and cracks. However, when ultraviolet rays are used for the crosslinking reaction, the hydrolyzable condensate can be crosslinked in a short time (within 15 minutes), and heat generation is small, so that wrinkles and cracks on the surface layer are hardly generated. Also, when the charging member is placed in an environment where the temperature and humidity change is abrupt, the surface layer will not wrinkle or wrinkle unless the surface layer sufficiently follows the expansion and contraction of the conductive elastic layer due to the change in temperature and humidity. Cracks may occur. For this reason, if the cross-linking reaction is performed with ultraviolet rays that generate less heat, the adhesion between the conductive elastic layer and the surface layer is increased, and the surface layer can sufficiently follow the expansion and contraction of the conductive elastic layer. In addition, wrinkles and cracks in the surface layer due to changes in environmental temperature and humidity can be suppressed.

  In addition, if the crosslinking reaction is performed using ultraviolet rays, it is possible to suppress deterioration of the conductive elastic layer due to thermal history, and thus it is possible to suppress a decrease in electrical characteristics of the conductive elastic layer.

For irradiation with ultraviolet rays, a high-pressure mercury lamp, a metal halide lamp, a low-pressure mercury lamp, an excimer UV lamp, or the like can be used. Among these, an ultraviolet ray source containing abundant light having an ultraviolet wavelength of 150 to 480 nm is used. The cumulative amount of ultraviolet light is preferably 6000 to 12000 mJ / cm ² from the viewpoint of sufficient curing of the composition and suppression of oxidation of the charging member surface. The integrated light quantity of ultraviolet rays is defined as follows.

UV integrated light quantity [mJ / cm ² ] = UV intensity [mW / cm ² ] × irradiation time [s].

  The adjustment of the integrated amount of ultraviolet light can be performed by the irradiation time, lamp output, and distance between the lamp and the irradiated object. Moreover, you may give a gradient to integrated light quantity within irradiation time.

  When a low-pressure mercury lamp is used, the integrated amount of ultraviolet light can be measured using an ultraviolet integrated light meter “UIT-150-A” or “UVD-S254” (both trade names) manufactured by USHIO INC. it can. When an excimer UV lamp is used, the integrated amount of ultraviolet light can be measured using an ultraviolet integrated light meter “UIT-150-A” or “VUV-S172” (both trade names) manufactured by USHIO INC. it can.

[Process cartridge, electrophotographic equipment]
FIG. 2 is a sectional view of the electrophotographic apparatus according to the present invention. In FIG. 2, photosensitive drums 1 a to 1 d are arranged in parallel in the moving direction of the intermediate transfer belt 6 so as to be opposed to developing means 4 a to 4 d such as developing units containing toner of respective colors. The color toner images formed on the photosensitive drums by the developing units are transferred to the intermediate transfer member electrostatically and sequentially by the transfer members 8a to 8d. Thereafter, a full-color toner image is formed with four color toners obtained by adding black (Bk) to yellow (Ye), magenta (Mg), and cyan (Cy). Further, charging members 2a to 2d, exposure means 3a to 3d, and developing means 4a to 4d for forming toner images of the respective colors on the photosensitive drums are disposed around the photosensitive drums 1a to 1d. Yes. Further, cleaning means 5a to 5d having cleaning blades that rub the toner remaining on the photosensitive drums and collect them after the toner image is transferred to the intermediate transfer belt 6 are disposed. The photosensitive drum 1 is driven to rotate at a predetermined peripheral speed (process speed) in a clockwise direction indicated by an arrow in the drawing.

  The charging member 2 is brought into contact with the photosensitive drum 1 with a predetermined pressing force, and is driven to rotate in the forward direction with respect to the rotation of the photosensitive drum 1 in this apparatus. By applying only a predetermined DC voltage to the charging member 2 from a charging bias application power source, the surface of the photosensitive drum 1 is uniformly charged to a predetermined polarity potential. The exposure unit 3 performs image exposure corresponding to target image information on the charged surface of the photosensitive drum 1 to form an electrostatic latent image on the photosensitive drum 1. The developing means 4 is disposed in an opening of a developing container for containing toner, and carries a toner carrying body for carrying and conveying the toner, an agitating part for stirring the contained toner, and a toner carrying amount (toner of the toner carrying body) And a toner regulating member that regulates the layer thickness. The developing unit 4 selectively attaches toner (negative toner) to the exposed bright portion of the electrostatic latent image on the surface of the photosensitive drum 1 to visualize the electrostatic latent image as a toner image. As the developing method, an existing jumping developing method, contact developing method, or magnetic brush method can be used. The transfer member 8 is brought into contact with the photosensitive drum 1 with a predetermined pressing force via the intermediate transfer belt 6 to form a transfer nip portion, and the rotational peripheral speed of the photosensitive drum 1 in the forward direction with the rotation of the photosensitive drum 1. Rotate at approximately the same peripheral speed. Further, a transfer voltage having a polarity opposite to the charging characteristics of the toner is applied from a transfer bias application power source. Residues on the photosensitive drum 1 such as transfer residual toner are collected from the photosensitive drum 1 by a cleaning means 5 such as a blade type.

  In the electrophotographic apparatus shown in FIG. 2, which is an example of the present invention, the photosensitive drums 1a to 1d, the charging members 2a to 2d, the developing means 4a to 4d, and the cleaning means 5a to 5d are directly incorporated in the electrophotographic apparatus. . However, an electrophotographic apparatus in which the photosensitive drum 1 and the charging member 2 are integrally supported by a support member such as a resin molded body and a process cartridge configured to be detachable from the main body of the electrophotographic apparatus may be mounted.

  Hereinafter, the present invention will be described in more detail with reference to specific examples. In the examples, “part” means “part by mass”.

<Example 1>
[Production of conductive elastic member]
First, the following compounds were kneaded with a 6 L kneader for 20 minutes.
・ Medium-high nitrile (trade name: “JSR N230SV” (bound acrylonitrile amount 35.0%), Mooney viscosity (ML _{1 + 4} 100 ° C.) 32, specific gravity 0.98, manufactured by JSR Corporation) 100 parts, filler as a color for carbon black (trade name: "# 7360SB", particle diameter 28nm, nitrogen adsorption specific surface area of 77m ² / g, DBP absorption amount of 87cm ³ / 100g, manufactured by Tokai carbon Co., Ltd.) as 48 parts filler 20 parts of calcium carbonate (trade name: “Nanox # 30”, manufactured by Maruo Calcium Co., Ltd.), 5 parts of zinc oxide and 1 part of zinc stearate.

  To this kneaded mixture for 20 minutes, 4.5 parts of tetrabenzylthiuram disulfide (trade name: “Sunceller TBZTD”, manufactured by Sanshin Chemical Industry Co., Ltd.) as a vulcanization accelerator, and sulfur 1.2 as a vulcanization agent And kneaded with an open roll for another 8 minutes. Thereby, kneaded material I was obtained.

  Next, a thermosetting adhesive (trade name: “Metallock N-33”, Co., Ltd.) containing a metal and rubber on a cylindrical steel support having a diameter of 6 mm and a length of 252 mm, the surface of which is nickel-plated. ) Manufactured by Toyo Chemical Laboratory. The coating was performed on a region of up to 115.5 mm on both sides across the center in the axial direction of the cylindrical surface of the support (in addition, a region having an axial width of 231 mm). This was dried at 80 ° C. for 30 minutes, and further dried at 120 ° C. for 1 hour.

  Next, using a cross head extruder, the kneaded product I is coated with the thermosetting adhesive and dried, and the kneaded product I has an outer diameter of 8.75 to 8.8 so as to cover the support. Extruded into a 90 mm cylinder. The end of the support was taken off while receiving the end, and the end was cut to a rubber length of 242 mm.

  Next, the kneaded material I covering the outer periphery of the support was vulcanized by passing through a continuous heating furnace. A continuous heating furnace having two zones with different temperature settings was used. The first zone was set at a temperature of 80 ° C. and allowed to pass in 30 minutes, the second zone was set at a temperature of 160 ° C., and this was also allowed to pass for 30 minutes to perform vulcanization.

  Next, both ends of the conductive elastic layer portion (rubber portion) of the vulcanized conductive elastic member were cut to make the axial width of the conductive elastic layer portion 232 mm. Thereafter, the surface of the conductive elastic layer portion was polished with a rotating grindstone to produce a crown shape having an end diameter of 8.26 mm and a center diameter of 8.5 mm. As a result, a conductive elastic member having a surface ten-point average roughness (Rz) of 5.5 μm and a deflection of 18 μm was obtained. The hardness of the conductive elastic member was 73 degrees (Asker C). The ten-point average roughness (Rz) was measured according to JISB6101. In addition, the measurement of shake was performed using a high-precision laser measuring machine “LSM-430v” (trade name) manufactured by Mitutoyo Corporation. Specifically, the outer diameter is measured using the measuring device, and the difference between the maximum outer diameter value and the minimum outer diameter value is defined as the outer diameter difference run. This measurement is performed at five points, and the average of the five outer diameter difference shakes is measured. The value was the runout of the object to be measured.

[Preparation of composition for forming polysiloxane-containing film]
Next, a method for preparing a composition for forming a polysiloxane-containing film will be described. First, as step (i), the following (A), (B), (C) and (E) were placed in a 300 ml eggplant flask.
(A) Glycidoxypropyltriethoxysilane (GPTES) (trade name: “KBE-403”, manufactured by Shin-Etsu Chemical Co., Ltd.) 25.78 g (0.093 mol) as a hydrolyzable silane compound
(B) Hexyltrimethoxysilane (HeTMS) (trade name: “KBM-3063”, manufactured by Shin-Etsu Chemical Co., Ltd.) 27.25 g (0.132 mol)
(C) Tetra i-propyl titanate 5N (Ti (O-iPr) ₄ , (Purity 99.999%, manufactured by Kojundo Chemical Laboratory Co., Ltd.) 6.26 g (0.022 mol))
(E) As primary alcohol, methanol (MeOH) (Kishida Chemical Co., Ltd. special grade) 50.00g, and as secondary alcohol, 2-butanol (2-BuOH) (Kishida Chemical Co., Ltd.) 56.61g.

  Furthermore, a football type stirring bar (total length 45 mm × diameter 20 mm) was added, and the mixture was stirred on a stirrer at room temperature for 1 minute at a rotation speed of 500 rpm and mixed. Furthermore, the rotation speed of the stirrer was changed to 900 rpm, and (D) 11.01 g of ion-exchanged water (pH = 5.5) was added dropwise. The solid content at the time of synthesis is 20.00 wt%. The molar ratio of (A), (B) and (C) to the total number of moles (100 mol%) of (A), (B) and (C) is (A) 37.43 mol% and (B) 53, respectively. .48 mol% and (C) 9.09 mol%. Next, by placing the flask in an oil bath set at 120 ° C. arranged on a stirrer with a temperature runaway prevention mechanism, by rotating at 750 rpm, reaching 120 ° C. for 20 minutes, and heating and refluxing for 3 hours, Condensate I was obtained.

(Measurement of condensate solids)
Here, measurement of the residual monomer amount of the condensate will be described. The calculation was performed on the mass determined from the structure in which the hydrolyzable silane compound and hydrolyzable titanium compound used were theoretically completely dehydrated and condensed. For measurement, A) an aluminum cup whose mass was measured in advance, and B) the obtained condensate was weighed with a precision balance of about 2.000 to 3.000 g. Further, it was left in an oven at 200 ° C. for 30 min, and then C) the weight was measured again with a precision balance, and the solid content was calculated by the following formula (6).

A: Mass of aluminum cup (g)
B: Mass of aluminum cup and condensate I (g)
C: Mass (g) of aluminum cup and condensate I after heating in the oven.

  If the solid content determined by measurement is equivalent to the theoretically determined mass, the residual monomer is very small. On the other hand, when there is an unreacted monomer in the oven, mass loss occurs due to volatilization. Therefore, if the solid content is measured, the residual monomer can be quantified. In this example, the solid content of the condensate I was 21.02% by mass.

(Condensate appearance evaluation)
Moreover, the following criteria evaluated the external appearance evaluation of the said condensate.
A: Condensate is uniform visually.
A: The condensate becomes slightly milky-white by visual observation, but can be used as a film-forming composition by filtration using a membrane filter having a pore size of 1.0 μm.
Δ: Condensate becomes milky-white visually, but can be used as a film-forming composition by filtration using a membrane filter having a pore size of 5.0 μm.
X: It becomes cloudy and precipitates are formed.

  Next, as step (ii), an aromatic sulfonium salt (trade name: “Adekaoptomer SP-150”, manufactured by ADEKA Corporation) as a cationic polymerization initiator as a photopolymerization initiator (F) is added with methanol. The concentration was adjusted to 10%. The photocationic polymerization initiator whose concentration was adjusted with methanol was added so that the photocationic polymerization initiator was 3.0 parts with respect to 100 parts of the solid content of 50 g of the condensate I. Next, it adjusted with ethanol so that the solid content of the condensate I might be 1.0 mass%, and it was set as the composition 1.

(Dielectric constant measurement)
The measurement of the dielectric constant of the film | membrane using the obtained composition 1 was performed with the following method. A film is formed by spin-coating the composition 1 on an aluminum sheet having a thickness of 100 μm using a spin coater (trade name: “1H-D7”, manufactured by Mikasa Co., Ltd.) at a rotation speed of 300 rpm for 2 seconds. did. Furthermore, it was cured by irradiating ultraviolet rays having a wavelength of 254 nm so that the integrated light amount was 9000 mJ / cm ² . A low-pressure mercury lamp manufactured by Harrison Toshiba Lighting Co., Ltd. was used for ultraviolet irradiation. The film produced on the aluminum sheet is subjected to platinum deposition, and a dielectric constant measuring device (using a 1296 type dielectric constant measuring interface and 1260 type impedance analyzer, manufactured by Solartron, UK) is used. Measured at 1 Hz to 1 MHz. Here, the dielectric constant was calculated using the electrostatic capacity at 10 Hz and the film thickness at the time of film formation. In this example, the dielectric constant ε of the film using the composition 1 was 18.5.

[Production of charging member]
Next, the composition 1 is applied on the conductive elastic layer of the produced conductive elastic member by ring application (discharge amount: 0.008 ml / s (ring portion speed: 20 mm / s, total discharge amount: 0.064 ml). ))did. Next, UV light having a wavelength of 254 nm was applied to the composition 1 ring-coated on the conductive elastic layer so that the integrated light amount was 9000 mJ / cm ² . As a result, the composition 1 was cured (cured by a crosslinking reaction), and the cured product was allowed to stand for several seconds and dried to form a surface layer. A low-pressure mercury lamp manufactured by Harrison Toshiba Lighting Co., Ltd. was used for ultraviolet irradiation. As described above, a charge having a support, a conductive elastic layer formed on the support, and a surface layer (a layer formed using the composition 1) formed on the conductive elastic layer. A member was prepared. The charging member produced as described above is referred to as charging member I.

(Film thickness of the surface layer)
The following method was used for the measurement of the film thickness of the surface layer formed using the composition 1. The thickness direction analysis of the outermost surface of the charging member I was performed by Ar + ion sputtering by direct ESCA. The following were used for the apparatus and measurement conditions.
Apparatus: “Quantum 2000” (trade name, manufactured by ULVAC-PHI),
X-ray: Monochrome Al kα, 25 w, 15 kV, 100 μm,
pass energy; 23.5 eV,
step width; 0.1 eV,
Sample tilt angle; 45,
Ar + sputtering: 4 kV, 2 × 2 mm ² , 6 sec / cycle
(Sputtering speed: 30 nm / min. SiO ₂ )
Analysis method: The film thickness was defined as the depth at which the Si2p3 peak intensity did not change.

  At this time, the film thickness of the surface layer of the charging member I was 35 nm.

(Evaluation of charging member)
The charging member I was evaluated as follows. First, the charging member I and the photosensitive drum were assembled in a process cartridge (product name: “Q5950A (black)”, manufactured by HP) that integrally supports them. The process cartridge was mounted on a laser beam printer (trade name: “HP Color LaserJet 4700 Printer”, manufactured by HP) for vertical output of A4 paper. The developing method of this laser beam printer is a reversal developing method, the output speed of the transfer material is 164 mm / s, and the image resolution is 600 dpi. The photosensitive drum incorporated in the process cartridge together with the charging member I is an organic photosensitive drum formed by forming an organic photosensitive layer having a layer thickness of 19 μm on a support. The organic photosensitive layer is a laminated photosensitive layer in which a charge generation layer and a charge transport layer containing a modified polyarylate (binder resin) are laminated from the support side, and the charge transport layer is a layer of a photosensitive drum. It is a surface layer. The toner used in the laser beam printer includes particles obtained by suspension polymerization of a polymerizable monomer system including a wax, a charge control agent, a dye, styrene, butyl acrylate, and an ester monomer in an aqueous medium. This is a so-called polymerized toner. This toner is a polymerized toner containing toner particles obtained by externally adding silica fine particles and titanium oxide fine particles to the particles, and has a glass transition temperature of 63 ° C. and a volume average particle size of about 6 μm. Image output was performed in an environment of 30 ° C./80% RH, and an E character pattern with a printing rate of 1% was formed on A4 paper, and this was output at 24,000 sheets at 6000 mm / day at a process speed of 164 mm / s. In the image evaluation, the occurrence of black streak-like image defects (hereinafter referred to as “charging streaks”) appearing as charging defects was observed. As an image used for the observation, an image (halftone image) in which a horizontal line having a width of 1 dot and an interval of 2 dots in the direction perpendicular to the rotation direction of the photosensitive drum was used on A4 paper. This was performed by visually observing the output image obtained at the time of outputting every 6000 sheets from the first (initial) of this image. The evaluation criteria are as follows. Table 3 shows the image evaluation results of the charging member I.
AA: No charging streaks appear on the output image A: A very small amount of charging streaks occurs on the edge of the output image B: A very small amount of charging streaks occurs on the entire surface of the output image C: On the entire surface of the output image A large amount of charged streaks occurred.

<Examples 2-28 and Comparative Examples 1-4>
Examples 2 to 28 and Comparative Examples 1 to 4 were respectively prepared in the same manner as in Example 1 with the blending ratios shown in Tables 3 to 6, and the same evaluation was performed.

  As described above, according to the present invention, the molar ratio of the hydrolyzable silane compounds (A) and (B) and the hydrolyzable titanium compound (C) and the alcohol used are appropriately selected. Thereby, there are almost no residual monomers after a synthesis | combination, and it becomes possible to suppress the cloudiness and phase-separation state by an excessive reaction of a hydrolyzable titanium compound (C), and to manufacture a composition uniformly. Furthermore, even if it is formed in a thick film, it is possible to eliminate defects during coating (coating unevenness, streaks, etc.). Furthermore, when cured by light irradiation, the cured film is densified to provide a charging member having both high dielectric properties. In addition, a process cartridge and an electrophotographic apparatus having the charging member can be provided.

1 Photosensitive drums 2a to 2d Charging members 3a to 3d Exposure means 4a to 4d Developing means 5a to 5d Cleaning means 6 Intermediate transfer belts 8a to 8d Transfer member P Transfer material 101 Support body 102 Conductive elastic layer 103 Surface layer

Claims (7)

A polysiloxane-containing film-forming composition comprising a condensate of a hydrolyzable silane compound and a hydrolyzable titanium compound, and a photopolymerization initiator,
The condensate contains 0.03 to 0.3 mol of a hydrolyzable titanium compound represented by the following formula (3) with respect to the hydrolyzable silane compound represented by the following formula (1) and the following formula (2). %. A composition for forming a polysiloxane-containing film, which is obtained by hydrolyzing a mixture of hydrolyzable compounds containing at a ratio of% in the presence of water and alcohol:
Formula (1)
R ¹ —Z—Si— (OR ² ) ₃
(In formula (1), R ¹ is an organic group capable of cationic polymerization, Z is a divalent organic group, R ² is a saturated or unsaturated hydrocarbon group),
Formula (2)
(R ³ ) ₁ —Si— (OR ² ) ₃
(In Formula (2), R ² represents a saturated or unsaturated hydrocarbon group, R ³ represents a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group),
Formula (3)
_{^{(R 3) x -Ti- (OR}} 2) 4-x
(In formula (3), x is an integer of 0 to 3, R ² is a saturated or unsaturated hydrocarbon group, R ³ is a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group) .   The composition according to claim 1, wherein the photopolymerization initiator includes a cationic polymerization initiator.   A charging member having at least a support and a conductive elastic layer and a surface layer on an outer periphery of the support, wherein the surface layer is a photocured film of a coating film of the composition according to claim 1 or 2. A charging member comprising:   A process cartridge comprising the charging member according to claim 3.   An electrophotographic apparatus comprising the charging member according to claim 3. A method for producing the composition of claim 1, comprising:
(I) The hydrolyzable titanium compound represented by the formula (3) is added in an amount of 0.03 to 0.3 mol% with respect to the hydrolyzable silane compound represented by the formula (1) and the formula (2). A step of hydrolyzing a mixture of hydrolyzable compounds contained in the ratio of water and alcohol in the presence of water to prepare a condensate of the hydrolyzable silane compound and the hydrolyzable titanium compound;
(Ii) A method for producing a composition for forming a polysiloxane-containing film, comprising the step of mixing the condensate and a photopolymerization initiator.   The production method according to claim 6, wherein the alcohol is a mixed liquid of a primary alcohol and a secondary alcohol, or a mixed liquid of a primary alcohol and a tertiary alcohol.

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