Image forming apparatus

Abstract

An image forming apparatus includes an electrophotographic photoreceptor having a conductive substrate and a photosensitive layer disposed on the conductive substrate, and a charging device having a charging member that charges a surface of the electrophotographic photoreceptor and a cleaning member disposed in contact with the charging member. The cleaning member includes an electrophotographic photoreceptor, and an outermost layer of the electrophotographic photoreceptor includes a charge transport material and a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B), the cleaning member having a core rod and a foamed elastic layer provided in a spiral shape on an outer peripheral surface of the core rod, the value of the ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer is 0.6 or more and 1.2 or less. [Chemical Formula 1] Formula (A) Formula (B)

Description

Technical Field

[0001] This invention relates to an image forming apparatus. Background Technology

[0002] Patent Document 1 discloses an image forming apparatus in which a latent image holder is charged by a charged member that contacts and rotates in conjunction with the latent image holder; the charged latent image holder is exposed to form an electrostatic latent image; the electrostatic latent image is developed by a toner carrier to form a toner image; the toner image formed on the latent image holder is transferred to a transfer piece by a transfer member that abuts against and rotates with the latent image holder; residual toner on the latent image holder after transfer is recovered by a cleaning unit; and the toner image on the transfer piece is fixed to the transfer piece by a fixing unit. The image forming apparatus is characterized in that the charged member has a material with high anti-stick properties on its surface, the transfer member is made of foam and has a surface layer on its surface.

[0003] Patent Document 2 discloses a charging device comprising: a charged component; and a cleaning component having a core and an elastic layer containing silicone oil and arranged in a spiral shape on the outer peripheral surface of the core. After the elastic layer of the cleaning component in the initial state is in contact with the charged component in the initial state for 24 hours, the maximum value of the content of Si atoms constituting the siloxane framework relative to the total atoms obtained by analyzing the surface of the charged component by X-ray photoelectron spectroscopy is 6 atomic% or less, in the contact portion (the area in contact with the elastic layer) and in the non-contact portion (the area not in contact with the elastic layer).

[0004] Patent document 3 discloses a positively charged laminated electrophotographic photosensitive layer, which has a laminated photosensitive layer formed on a conductive substrate, wherein a charge transport layer composed of at least a hole transport material and a binder resin and a charge generation / transport layer composed of at least a charge generation material, an electron transport material, a hole transport material and a binder resin are sequentially stacked. The binder resin in the charge transport layer contains polyarylate resin, and the thickness of the charge transport layer is 10 to 40 μm, and the thickness of the charge generation / transport layer is 3 to 20 μm.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2005-309039

[0006] Patent Document 2: Japanese Patent Application Publication No. 2012-78518

[0007] Patent Document 3: Japanese Patent Application Publication No. 2014-146001 Summary of the Invention

[0008] The objective of this invention is to provide an image forming apparatus with excellent abrasion suppression of the photoreceptor and contamination suppression of charged components, compared to cases where the outermost layer of an electrophotographic photoreceptor does not contain a charge transport material, is a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B), or where the cleaning component has a core rod and a foamed elastic layer spirally disposed on the outer peripheral surface of the core rod, and the ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer is less than 0.6 or greater than 1.2.

[0009] Solutions to the aforementioned problem include the following approaches.

[0010] <1> An image forming apparatus comprising: an electrophotographic photoreceptor and a charging device having a charging member for charging the surface of the electrophotographic photoreceptor and a cleaning member disposed in contact with the charging member, the electrophotographic photoreceptor having a conductive substrate and a photosensitive layer disposed on the conductive substrate, and the outermost surface layer of the electrophotographic photoreceptor comprising a charge transport material and a polyaryl ester resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B), the cleaning member having a core rod and a foamed elastic layer disposed in a spiral shape on the outer peripheral surface of the core rod, the ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer being 0.6 or more and 1.2 or less.

[0011] [Chemical Formula 1]

[0012] Formula (A)

[0013] Formula (B)

[0014] In equation (A), Ar A1 and Ar A2 Each is an aromatic ring that can have substituents, L A It is a single bond or a divalent linker, n A1 It can be 0, 1, or 2.

[0015] In equation (B), Ar B1 and Ar B2 Each is an aromatic ring that can have substituents, L B It is a single bond, an oxygen atom, a sulfur atom, or -C(Rb) 1 (Rb) 2 )-,n B1 It can be 0, 1, or 2. Rb 1 and Rb 2Rb is independently composed of hydrogen atoms, an alkyl group having 1 or more but less than 20 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 1 With Rb 2 They can bond together to form cyclic alkyl groups.

[0016] <2> According to the image forming apparatus described in <1>, the coverage area A of the foamed elastic layer disposed on the cleaning member is 20% or more and 60% or less.

[0017] <3> The image forming apparatus according to <1> or <2>, wherein the surface roughness Rz of the charged component is 5 μm or more and 10 μm or less.

[0018] <4> The image forming apparatus according to any one of <1> to <3>, wherein the outermost layer of the electrophotographic photoreceptor further comprises a polycarbonate resin.

[0019] <5> According to the image forming apparatus of <4>, the mass ratio of the polyarylate resin to the polycarbonate resin in the outermost layer of the electrophotographic photoreceptor is 3:7 to 7:3.

[0020] <6> The image forming apparatus according to any one of <1> to <5>, wherein the dicarboxylic acid unit represented by formula (A) comprises at least one selected from the group consisting of dicarboxylic acid unit (A1) represented by formula (A2), dicarboxylic acid unit (A3) represented by formula (A4), and dicarboxylic acid unit (A5) represented by formula (A5).

[0021] [Chemical Formula 2]

[0022] Equation (A1)

[0023] Formula (A2)

[0024] Formula (A3)

[0025] Equation (A4)

[0026] Formula (A5)

[0027] In equation (A1), n 101 n is an integer greater than 0 and less than 4. 101 Ra 101Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0028] In equation (A2), n 201 and n 202 Each of the following is an independent integer greater than 0 and less than 4, n 201 Ra 201 and n 202 Ra 202 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0029] In equation (A3), n 301 and n 302 Each of the following is an independent integer greater than 0 and less than 4, n 301 Ra 301 and n 302 Ra 302 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0030] In equation (A4), n 401 n is an integer greater than 0 and less than 6. 401 Ra 401 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0031] In equation (A5), n 501 n 502 and n 503 Each of the following is an independent integer greater than 0 and less than 4, n 501 Ra 501 n 502 Ra 502 and n 503 Ra 503 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0032] <7> The image forming apparatus according to any one of <1> to <6>, wherein the diol unit represented by formula (B) comprises at least one selected from the group consisting of the diol unit (B1) represented by formula (B1), the diol unit (B2) represented by formula (B2), the diol unit (B3) represented by formula (B3), the diol unit (B4) represented by formula (B4), the diol unit (B5) represented by formula (B5), the diol unit (B6) represented by formula (B6), the diol unit (B7) represented by formula (B7), and the diol unit (B8) represented by formula (B8).

[0033] [Chemical Formula 3]

[0034] Formula (B1)

[0035] Formula (B2)

[0036] Formula (B3)

[0037] Equation (B4)

[0038] [Chemical Formula 4]

[0039] Formula (B5)

[0040] Formula (B6)

[0041] Formula (B7)

[0042] Formula (B8)

[0043] In equation (B1), Rb 101 Branched alkyl groups with 4 or more but less than 20 carbon atoms, Rb 201 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 401 、Rb 501 、Rb 801 and Rb 901 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0044] In equation (B2), Rb 102 Rb is a straight-chain alkyl group with 4 or more but less than 20 carbon atoms. 202 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 402 、Rb 502 、Rb 802 and Rb 902Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0045] In equation (B3), Rb 113 and Rb 213 Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where d is an integer between 7 and 15, and Rb 403 、Rb 503 、Rb 803 and Rb 903 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0046] In equation (B4), Rb 104 and Rb 204 Each is independently an alkyl group having 1 or more but less than 3 carbon atoms, Rb 404 、Rb 504 、Rb 804 and Rb 904 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0047] In equation (B5), Ar 105 Rb is an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 205 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 405 、Rb 505 、Rb 805 and Rb 905 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0048] In equation (B6), Rb 116 and Rb 216 Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where e is an integer of 4 or more but less than 6, and Rb 406 、Rb 506 、Rb 806 and Rb 906 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0049] In equation (B7), Rb 407 、Rb 507、Rb 807 and Rb 907 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0050] In equation (B8), Rb 408 、Rb 508 、Rb 808 and Rb 908 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0051] <8> The image forming apparatus according to <4>, wherein the polyarylate resin and the polycarbonate resin each have a structural unit comprising biphenyl represented by the following formula (BP).

[0052] [Chemical Formula 5]

[0053] Formula (BP)

[0054] In equation (BP), j is an integer greater than 0 and less than 4, and j are R... 1 Each is independently methyl or ethyl, k is an integer greater than or equal to 0 and less than or equal to 4, and k R's are independent of each other. 2 Each can be methyl or ethyl, independently.

[0055] Invention Effects

[0056] According to the invention described in <1>, compared to cases where the outermost layer of an electrophotographic photoreceptor does not contain a charge-transporting material, is a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B), or where the cleaning component has a core rod and a foamed elastic layer spirally disposed on the outer peripheral surface of the core rod, and the value of the ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer is less than 0.6 or greater than 1.2, an image forming apparatus with excellent wear suppression of the photoreceptor and contamination suppression of charged components is provided.

[0057] According to the invention described in <2>, an image forming apparatus is provided that provides superior contamination suppression of charged components compared to cases where the coverage area A of the foamed elastic layer provided on the cleaning component is less than 20% or more than 60%.

[0058] According to the invention described in <3>, an image forming apparatus is provided that provides superior contamination suppression of the charged component compared to cases where the surface roughness Rz of the charged component is less than 5 μm or greater than 10 μm.

[0059] According to the invention described in <4>, compared with the case where the outermost layer of the electrophotographic photoreceptor only contains polyarylate resin, an image forming apparatus is provided that has superior resistance to wear of the photoreceptor and resistance to contamination of charged parts.

[0060] According to the invention described in <5>, an image forming apparatus is provided that provides superior resistance to abrasion of the photoreceptor and resistance to contamination of charged parts compared to cases where the mass ratio of the polyarylate resin to the polycarbonate resin in the outermost layer of the electrophotographic photoreceptor is less than 3:7 or greater than 7:3.

[0061] According to the invention described in <6>, compared to the case where the dicarboxylic acid unit represented by formula (A) does not include at least one selected from the group consisting of dicarboxylic acid unit (A1) represented by formula (A2), dicarboxylic acid unit (A3) represented by formula (A4), and dicarboxylic acid unit (A5) represented by formula (A5), an image forming apparatus with superior resistance to wear of the photoreceptor and resistance to contamination of charged components is provided.

[0062] According to the invention described in <7>, compared to the case where the diol unit represented by formula (B) does not include at least one selected from the group consisting of diol unit (B1) represented by formula (B1), diol unit (B2) represented by formula (B2), diol unit (B3) represented by formula (B3), diol unit (B4) represented by formula (B4), diol unit (B5) represented by formula (B5), diol unit (B6) represented by formula (B6), diol unit (B7) represented by formula (B7) and diol unit (B8) represented by formula (B8), an image forming apparatus with superior resistance to wear of the photoreceptor and resistance to contamination of charged components is provided.

[0063] According to the invention described in <8>, compared to the case where the polyarylate resin and the polycarbonate resin do not each have a structural unit containing biphenyl represented by the following formula (BP), an image forming apparatus with excellent photoreceptor abrasion suppression is provided. Attached Figure Description

[0064] The embodiments of the present invention will be described in detail with reference to the following figures.

[0065] Figure 1 This is an enlarged cross-sectional view showing an example of the foamed elastic layer in the cleaning component used in this embodiment;

[0066] Figure 2 This is a side view showing a schematic structure of an example of the live device used in this embodiment;

[0067] Figure 3 This is a front view showing a schematic structure of an example of the live device used in this embodiment;

[0068] Figure 4 This is a schematic side view showing an example of a cleaning component used in the energized device used in this embodiment;

[0069] Figure 5 This is a partial cross-sectional view showing an example of the layer structure of an electrophotographic photoreceptor;

[0070] Figure 6 This is a partial cross-sectional view showing another example of the layer structure of an electrophotographic photoreceptor;

[0071] Figure 7 This is a schematic structural diagram illustrating an example of the image forming apparatus according to this embodiment;

[0072] Figure 8 This is a schematic structural diagram showing another example of the image forming apparatus according to this embodiment.

[0073] Symbol Explanation

[0074] 102 - Core rod, 104 - Foamed elastic layer, 106 - Adhesive layer (double-sided tape), 108 - Elastic component, 110 - Cut-out portion, T1, T2 - Thickness of foamed elastic layer 104, W3, W4 - Width of foamed elastic layer 104.

[0075] 1A - Electrification device, 10 - Electrified roller (electrified component), 12 - Cleaning roller (cleaning component), 18 - Core rod, 20 - Foamed elastic layer, 24 - Photoreceptor (image retainer).

[0076] 1-Conductive substrate, 2-Undercoat layer, 3-Charge generation layer, 4-Charge transport layer, 5-Photosensitive layer, 10A-Photoreceptor, 10B-Photoreceptor.

[0077] 7-Electrophotographic photosensitive element, 8-Electrified device, 9-Exposure device, 11-Developing device, 13-Cleaning device, 14-Lubricant, 40-Transfer device, 50-Intermediate transfer body, 100-Image forming device, 120-Image forming device, 131-Cleaning scraper, 132-Fiber-like component (roller-like), 133-Fiber-like component (flat brush-like), 300-Processing box. Detailed Implementation

[0078] Hereinafter, a detailed description will be given as an example of an embodiment of the present invention.

[0079] In this specification, the numerical range represented by “~” indicates the range to be included by taking the values ​​before and after “~” as the minimum and maximum values, respectively.

[0080] In the numerical ranges described in this specification, the upper or lower limit of a numerical range can be replaced with the upper or lower limit of other numerical ranges described in different periods. Furthermore, within the numerical ranges described in this specification, the upper or lower limit of that range can be replaced with the values ​​shown in the embodiments.

[0081] In this specification, the term "process" includes not only individual processes, but also processes that achieve their purpose, even if they cannot be clearly distinguished from other processes.

[0082] In this specification, when embodiments are described with reference to the accompanying drawings, the structure of the embodiments is not limited to the structure shown in the drawings. Furthermore, the sizes of the components in the figures are conceptual, and the relative sizes of the components are not limited thereto.

[0083] In this specification, each component may contain multiple corresponding substances. In this embodiment, when referring to the amount of each component in the composition, if multiple substances corresponding to each component are present in the composition, it indicates the total amount of the multiple substances present in the composition unless otherwise specified.

[0084] This specification may include multiple particles corresponding to each component. When multiple particles corresponding to each component are present in the composition, unless otherwise specified, the particle size of each component represents a value with respect to the mixture of the multiple particles present in the composition.

[0085] Unless otherwise specified in this specification, alkyl and alkylene groups include straight-chain, branched, and cyclic forms.

[0086] In this specification, regarding organic groups, aromatic rings, linking groups, alkyl groups, alkylene groups, aryl groups, aralkyl groups, alkoxy groups, aryloxy groups, etc., the hydrogen atoms in these groups may be replaced by halogen atoms.

[0087] In this specification, when compounds are represented by structural formulas, sometimes the symbols (C and H) representing the hydrocarbon group and / or the carbon and hydrogen atoms in the hydrocarbon chain are omitted.

[0088] In this specification, the term "structural unit" for copolymers or resins has the same meaning as that for monomer units.

[0089] In this specification, ppm is short for parts per million, which is a quality standard.

[0090] (Image forming apparatus)

[0091] The image forming apparatus according to this embodiment includes: an electrophotographic photosensitive element and a charging device, comprising a charging member for charging the surface of the electrophotographic photosensitive element and a cleaning member disposed in contact with the charging member. The electrophotographic photosensitive element has a conductive substrate and a photosensitive layer disposed on the conductive substrate. The outermost surface layer of the electrophotographic photosensitive element comprises a charge transport material and a polyaryl ester resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B). The cleaning member has a core rod and a foamed elastic layer disposed in a spiral shape on the outer peripheral surface of the core rod. The ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer is 0.6 or more and 1.2 or less.

[0092] [Chemical Formula 6]

[0093] Formula (A)

[0094] Formula (B)

[0095] In equation (A), Ar A1 and Ar A2 Each is an aromatic ring that can have substituents, L A It is a single bond or a divalent linker, n A1 It can be 0, 1, or 2.

[0096] In equation (B), Ar B1 and Ar B2 Each is an aromatic ring that can have substituents, L B It is a single bond, an oxygen atom, a sulfur atom, or -C(Rb) 1 (Rb) 2 )-,n B1 It can be 0, 1, or 2. Rb 1 and Rb 2 Rb is independently composed of hydrogen atoms, an alkyl group having 1 or more but less than 20 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 1 With Rb 2 They can bond together to form cyclic alkyl groups.

[0097] In existing image forming apparatuses, if contaminants on charged components are continuously pressed by cleaning components, the contaminants will gradually solidify (form a film).

[0098] Furthermore, in existing image forming apparatuses, wear and tear on the photoreceptor occurs frequently.

[0099] The electrophotographic photosensitive material of this embodiment comprises a charge transport material and a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B). The cleaning member has a core rod and a foamed elastic layer spirally disposed on the outer peripheral surface of the core rod. The ratio T / W of the thickness T of the foamed elastic layer to its width W is 0.6 or more and 1.2 or less. The mechanism based on this is presumed as follows: The polyarylate resin inhibits abrasion of the photosensitive material, and by using the cleaning member, contact pressure is generated in both continuous and intermittent portions, resulting in excellent contamination removal, suppression of film formation, and excellent contamination suppression of charged components.

[0100] [Electrified devices]

[0101] The image forming apparatus according to this embodiment includes a charging device, which has a charging member for charging the surface of an electrophotographic photosensitive element and a cleaning member disposed in contact with the charging member. The cleaning member has a core rod and a foamed elastic layer disposed in a spiral shape on the outer peripheral surface of the core rod. The ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer is 0.6 or more and 1.2 or less.

[0102] <T / W value of foamed elastic layer>

[0103] The ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer is 0.6 or more and 1.2 or less. From the viewpoint of pollution suppression of charged parts, it is preferably 0.60 or more and 1.05 or less, more preferably 0.70 or more and 0.95 or less, and especially preferably 0.75 or more and 0.90 or less.

[0104] The thickness T of the foamed elastic layer is set as the thickness of the part of the foamed elastic layer with the smallest thickness.

[0105] Furthermore, as described later, when the foamed elastic layer is configured as a double helix, triple helix, or similar shape, it is preferable that two or more helical foamed elastic layers each satisfy the T / W value. Additionally, the width W of the foamed elastic layer is the width of each helical foamed elastic layer.

[0106] Figure 1 This is an enlarged cross-sectional view showing an example of the foamed elastic layer in the cleaning component used in this embodiment. Figure 1In the cleaning component shown, three or more foamed elastic layers 104 are wound onto the core rod 102 in a bundled state via the cut portion 110. As described above, regarding the divided foamed elastic layers 104, each divided foamed elastic layer (104A, 104B) has a protrusion in the width direction that protrudes in the direction of radially outward from the core.

[0107] In such Figure 1 In the cleaning components shown, the thickness T and width W of each foamed elastic layer are, i.e. Figure 1 The T1 / W3 and T2 / W4 in the figure preferably satisfy the value of T / W.

[0108] From the viewpoint of pollution suppression of charged components, the width W of the foamed elastic layer is preferably 1.0 mm or more and 5.0 mm or less, more preferably 1.5 mm or more and 4.0 mm or less, and especially preferably 2.0 mm or more and 4.0 mm or less.

[0109] From the viewpoint of pollution suppression of charged components, the thickness T of the foamed elastic layer is preferably 1.5 mm or more and 7.0 mm or less, more preferably 2.0 mm or more and 6.0 mm or less, even more preferably 2.5 mm or more and 4.5 mm or less, and especially preferably 2.5 mm or more and 4.0 mm or less.

[0110] In this embodiment, the thickness and width of the foamed elastic layer are measured using a laser displacement meter or calipers.

[0111] <Coverage ratio A of the foamed elastic layer>

[0112] From the viewpoint of pollution suppression of charged components, the coverage area A of the foamed elastic layer provided on the cleaning component is preferably 10% or more and 70% or less, more preferably 20% or more and 60% or less, and especially preferably 30% or more and 60% or less.

[0113] The coverage area ratio A of the foamed elastic layer represents the proportion of the area covered by the foamed elastic layer relative to the entire circumference of the mandrel. That is, it can also be expressed as... Figure 4 The spiral width R1 of the foamed elastic layer 20 is represented by [the spiral width R1 of the foamed elastic layer 20 + the pitch R2 of the foamed elastic layer 20].

[0114] <Surface roughness Rz of charged components>

[0115] From the viewpoint of pollution suppression of charged components, the surface roughness Rz of the charged components is preferably 3 μm or more and 12 μm or less, preferably 5 μm or more and 10 μm or less, and especially preferably 5 μm or more and 7 μm or less.

[0116] The surface roughness Rz of the charged parts was measured using a SURFCOM roughness meter (manufactured by TOKYO SEIMITSU CO.,LTD.).

[0117] <Number of windings in the foamed elastic layer>

[0118] The foamed elastic layer can be in the form of a single spiral, a double spiral, or a triple spiral.

[0119] From the viewpoint of pollution suppression of charged components, the number of coils of the foamed elastic layer on the mandrel is preferably one or more and five or less, more preferably one or more and three or less, even more preferably two or three, and especially preferably three.

[0120] The shapes of the charged components and cleaning components involved in this embodiment are not particularly limited as long as they meet the above conditions.

[0121] Hereinafter, as an example of a charged component, the charged roller and cleaning component involved in this embodiment will be described. Of course, the structural materials of each layer of the charged component or cleaning component can also be used for charged components or cleaning components of other shapes.

[0122] Figure 2 This is a side view showing a schematic structure of an example of the charged device according to this embodiment. Furthermore, Figure 3 This is a front view showing a schematic structure of an example of the energized device involved in this embodiment. Figure 4 This is a schematic side view showing an example of a cleaning component used in a live device according to this embodiment.

[0123] Figure 2 and Figure 3 The electrification device 1A shown includes a cylindrical electrified component, namely an electrified roller 10, which electrifies the surface of the image holder in the image forming apparatus and rotates about an axis, and a cleaning component, namely a cleaning roller 12, which contacts the electrified roller 10 and is used to clean the surface of the electrified roller 10.

[0124] The charged roller 10, for example, has a conductive core 14 and a charged layer 16 formed on the outer periphery of the conductive core 14. The charged layer 16 may have a conductive elastic layer, and may have a surface layer or the like as needed.

[0125] like Figure 4 As shown, the cleaning roller 12 is a roller-shaped component having a core rod 18 and a foamed elastic layer 20 formed on the outer periphery of the core rod 18. The foamed elastic layer 20 is arranged in a spiral shape on the surface of the core rod 18. Specifically, the foamed elastic layer 20 is arranged, for example, in a spiral shape wound from one end of the core rod 18 to the other end, with the axis of the core rod 18 set as a spiral axis and spaced apart.

[0126] like Figure 3 As shown, in the charging device 1A, the charging roller 10 is pressed against the surface of the photosensitive core 14 by elastic members such as helical springs 26 provided at both ends of the photosensitive core 14, which serves as an image holder, and is driven by the photosensitive core 24. On the other hand, the cleaning roller 12 is held by a bearing 28 at the distance between the conductive core 14 of the charging roller 10 and the core rod 18 of the cleaning roller 12, and the cleaning roller 12 contacts the charging roller 10 with a predetermined biting (engagement) amount and is driven by it. In addition, the charging roller 10 and the cleaning roller 12 can be driven by the photosensitive core 24 and the charging roller 10 respectively, or they can be driven independently.

[0127] <Cleaning Parts>

[0128] The following describes each layer of the cleaning components, such as the cleaning roller 12. As for the structure of the cleaning components, there are no particular limitations as long as it has the cleaning function of an electrified component such as an electrified roller and meets the aforementioned necessary conditions. A structure that does not produce scratches, contamination, or other defects on the surface of the electrified roller that affect image quality is preferred.

[0129] The materials used in the mandrel 18 of the cleaning roller 12, which is in the shape of a roller, include free-cutting steel, stainless steel, and other metals, as well as resins such as polyoxymethylene (POM). The material and surface treatment method of the mandrel 18 are selected based on applications such as sliding properties. Especially when the mandrel 18 is made of metal, plating can be performed for rust prevention. Furthermore, when the mandrel 18 is made of a non-conductive material such as resin, it can be processed and made conductive through conventional treatments such as plating, and can be used directly.

[0130] Additionally, the outer diameter of the mandrel 18 can be exemplified by, for example... The above and The following range.

[0131] The structure of the foamed elastic layer 20 on the mandrel 18 can be a single layer or a stacked structure of two or more layers. The foamed elastic layer 20 can be composed of a foam body or a two-layer structure consisting of a solid layer and a foam layer. By setting the foamed elastic layer 20 as a structure for cleaning the surface of charged parts, it achieves the function of a cleaning roller.

[0132] As the material constituting the foamed elastic layer 20, a material can be made by mixing one or more of the following: foaming resins such as polyurethane, polyethylene, polyamide, or polypropylene; or rubber materials such as silicone rubber, fluororubber, polyurethane rubber, ethylene-propylene-diene rubber (EPDM), nitrile rubber (NBR), chloroprene rubber (CR), chlorinated polyisoprene rubber, isoprene rubber, acrylonitrile-butadiene rubber, styrene-butadiene rubber, hydrogen-added polybutadiene rubber, and butyl rubber. Foaming agents, foam stabilizers, catalysts, curing agents, plasticizers, vulcanization accelerators, etc., can be added as needed.

[0133] As for the material constituting the foamed elastic layer 20, from the viewpoint of easy removal of foreign matter, materials containing air bubbles (so-called foams) are particularly preferred among the materials mentioned above. In particular, in order to avoid scratches on the surface of charged parts due to friction, and to prevent breakage or damage during long-term use, foamed polyurethane with high tear strength and tensile strength is preferred.

[0134] There are no particular limitations on the type of polyurethane, but examples include polyurethanes obtained by reacting polyols such as polyester polyols, polyether polyols, and acrylic polyols with isocyanates such as 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, 4,4-diphenylmethane diisocyanate, toluidine diisocyanate, and 1,6-hexane diisocyanate. Furthermore, chain extenders such as 1,4-butanediol and trimethylolpropane can be added. Foaming agents such as water, azodicarbonamide, and azobisisobutyronitrile can be used. Additives such as foaming agents, foam stabilizers, and catalysts can also be added as needed.

[0135] Furthermore, among the aforementioned foamed polyurethanes, polyether-based polyurethanes (ether-based foamed polyurethanes) that use polyether polyols as raw materials for urethanes are preferred. Compared with polyester-based polyurethanes, they are less prone to hydrolysis and therefore have good shelf life under high temperature and high humidity conditions (e.g., temperature 45°C and humidity 95%).

[0136] Examples of silicone-based foam stabilizers include the aforementioned silicone oils.

[0137] In particular, when polyether polyurethane is used in the manufacture of polyether polyurethane, since silicone oil is often used as a foaming agent, the foamed elastic layer 20 usually contains silicone oil when polyether polyurethane is used as the material of the elastic layer 20.

[0138] like Figure 4 As shown, the foamed elastic layer 20 is arranged in a spiral shape, but specifically, for example, a spiral shape with a spiral angle θ of 10° or more and 65° or less (for example, preferably 20° or more and 50° or less) can be cited.

[0139] In addition, the aforementioned helical angle θ refers to the angle (acute angle) at which the length direction P (helical direction) of the foamed elastic layer 20 intersects the axial direction Q (core axis) of the mandrel 18.

[0140] The spiral width R1 refers to the length along the axial direction Q (core axis) of the core rod 18 in the foamed elastic layer 20.

[0141] The helical spacing R2 refers to the length between adjacent foamed elastic layers 20 along the axial direction Q (core axis) of the core rod 18 in the foamed elastic layer 20.

[0142] Furthermore, the foamed elastic layer 20 refers to a layer made of a material that can recover its original shape after being deformed by an external force of 100 Pa.

[0143] <Electrified Components>

[0144] Next, the charged roller 10, which is a charged component, will be described. However, the structure is not limited to the following as long as it has a predetermined charging performance that enables the image holder, which is a charged object, to be charged.

[0145] The charged roller 10 is configured, for example, to include a conductive core 14 and a charged layer 16 containing an elastic layer or a resin layer. The charged layer 16 can be a single-layer structure of the elastic layer, or a stacked structure of multiple different layers with various functions. Furthermore, the elastic layer may have undergone surface treatment. Here, "conductivity" refers to a volume resistivity of 1×10⁻⁶ at 20°C. 7 Below Ωcm. The same applies below.

[0146] The materials used in the conductive core 14 can include, for example, free-machining steel, stainless steel, and other metals. The material and surface treatment method can be selected according to the intended use, such as the smoothness of the surface. From the perspective of rust prevention, the conductive core 14 can be plated. If the material of the conductive core 14 is non-conductive, it can be processed and made conductive through conventional methods such as plating, or it can be used directly.

[0147] To obtain predetermined electrical properties, the elastic layer can be designed as a conductive elastic layer. Examples of conductive elastic layers include: an elastic material such as elastic rubber; a conductive material such as carbon black or an ionic conductive agent to adjust the resistance of the conductive elastic layer; and additives such as softeners, plasticizers, curing agents, vulcanizing agents, vulcanization accelerators, anti-aging agents, silica, and calcium carbonate fillers, added as needed. The conductive elastic layer is formed, for example, by coating a mixture of the above materials onto the peripheral surface of the conductive core 14. As a conductive agent for adjusting the resistance value, carbon black, ionic conductive agents, or conductive materials dispersed from a matrix material can be used. Furthermore, the elastic material can be a foam.

[0148] The elastic material constituting the conductive elastic layer is formed, for example, by dispersing a conductive agent in a rubber material. Examples of rubber materials include isoprene rubber, chloroprene rubber, epichlorohydrin rubber, butyl rubber, polyurethane rubber, silicone rubber, fluororubber, styrene-butadiene rubber, butadiene rubber, nitrile rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, ethylene-propylene-diene ternary copolymer rubber (EPDM), acrylonitrile-butadiene copolymer rubber, natural rubber, and blends thereof. Silicone rubber, ethylene propylene rubber, epichlorohydrin-ethylene oxide copolymer rubber, epichlorohydrin-ethylene oxide-allyl glycidyl ether copolymer rubber, acrylonitrile-butadiene copolymer rubber, and blends thereof are used. These rubber materials can be foamed or non-foamed.

[0149] As conductive agents, electronic conductive agents or ionic conductive agents are used. Examples of electronic conductive agents include carbon black such as Ketjen black and acetylene black; various conductive metals or alloys such as thermally decomposed carbon, graphite, aluminum, copper, nickel, and stainless steel; various conductive metal oxides such as tin oxide, indium oxide, titanium oxide, tin oxide-antimony oxide solid solutions, and tin oxide-indium oxide solid solutions; conductive materials whose surfaces have been conductively treated; and micro powders. Examples of ionic conductive agents include perchlorates and chlorates such as tetraethylammonium and lauryltrimethylammonium; and perchlorates and chlorates of alkali metals and alkaline earth metals such as lithium and magnesium.

[0150] These conductive agents can be used alone or in combination of two or more. Furthermore, there are no particular limitations on the amount added; however, in the case of the aforementioned electronic conductive agents, the amount can range from 1 part to 60 parts by weight relative to 100 parts by weight of the rubber material. On the other hand, in the case of the aforementioned ionic conductive agents, the amount can range from 0.1 parts to 5.0 parts by weight relative to 100 parts by weight of the rubber material.

[0151] To prevent contamination caused by foreign matter such as colorants, a surface layer can be formed on the surface of the charged roller 10. The material for the surface layer can be any of resins and rubbers, without particular limitation. Examples of resins or rubbers include polyester, polyimide, copolynylon, silicone resin, acrylic resin, polyvinyl butyral, ethylene tetrafluoroethylene copolymer, melamine resin, fluororubber, epoxy resin, polycarbonate, polyvinyl alcohol, cellulose, polyvinylidene chloride, polyvinyl chloride, polyethylene, and ethylene vinyl acetate copolymer.

[0152] Among these materials, from the viewpoint of suppressing contamination from colorant additives, polyvinylidene fluoride, tetrafluoroethylene copolymers, polyesters, polyimides, and copolynylons can be used. Copolynylons include one or more of 610 nylon, 11 nylon, and 12 nylon as polymerization units, and other polymerization units included in the copolymer include 6 nylon, 66 nylon, etc. Here, the proportion of 610 nylon, 11 nylon, 12 nylon, etc., polymerization units in the copolymer is preferably, for example, 10% or more by mass.

[0153] The aforementioned resin or rubber can be used alone, or two or more can be used in combination, or a mixture of resin and rubber can be used. Furthermore, the number average molecular weight of the resin or rubber is preferably in the range of 1,000 or more and 100,000 or less, more preferably in the range of 10,000 or more and 50,000 or less.

[0154] Furthermore, the aforementioned surface layer may contain a conductive material to adjust the resistance value. For example, a conductive material with a particle size of 3 μm or less is preferably used as this conductive material.

[0155] Furthermore, as a conductive agent for adjusting the resistance value, carbon black, conductive metal oxide particles or ionic conductive agents incorporated in the matrix material, or conductive materials obtained by dispersing materials that conduct electricity using at least one of electrons and ions as charge carriers can be used.

[0156] Carbon black used as a conductive agent, specifically, can be exemplified by, for example, "SpecialBlack 350", "SpecialBlack 100", "SpecialBlack 250", "SpecialBlack 5", "SpecialBlack 4", "Special Black 4A", "SpecialBlack 550", "SpecialBlack 6", "Color Black FW200", "Color Black FW2", "Color Black FW2V" manufactured by Degussa, "MONARCH 1000" manufactured by Cabot Corporation, "MONARCH 1300" manufactured by Cabot Corporation, "MONARCH 1400" manufactured by Cabot Corporation, "MOGUL-L", and "REGAL 400R", all of which have a pH below 4.0.

[0157] Conductive metal oxide particles used to adjust the resistance value can include, for example, tin oxide, antimony-doped tin oxide, zinc oxide, anatase titanium oxide, and ITO, etc. Any conductive particle that uses electrons as charge carriers can be used, without particular limitation. These can be used individually or in combination. Furthermore, any particle size is acceptable as long as it does not impede the effect of this embodiment; however, considering resistance adjustment and strength, tin oxide, antimony-doped tin oxide, and anatase titanium oxide are preferred, and tin oxide or antimony-doped tin oxide is more preferred.

[0158] Furthermore, the surface layer is constructed using a fluorinated or silicone-based resin, particularly preferably containing a fluorinated modified acrylate polymer. Particles can also be added to the surface layer. This makes the surface layer hydrophobic, preventing foreign matter from adhering to the charged roller 10. Insulating particles such as alumina or silica can be added to give the surface of the charged roller an uneven texture, reducing the burden of sliding friction with the photosensitive drum and thus improving the mutual wear resistance between the charged roller and the image holder. Here, "insulation" refers to a volume resistivity of 1×10⁻⁶ at 20°C. 13 Above Ωcm. The same applies below.

[0159] The outer diameter of the charged roller 10 is preferably 8 mm or more and 16 mm or less. From the viewpoint of miniaturizing the image forming apparatus, it is preferably... The following, if it is Consequently, the number of times the additive comes into contact with the circumference of each charged roller increases, and the number of discharges also increases, which can sometimes be detrimental to maintaining the charging performance. Furthermore, the outer diameter can be measured using commercially available calipers or laser-based outer diameter measuring devices.

[0160] The microhardness of the charged roller 10 is preferably 45° or higher and 60° or lower. If it is harder than 60°, even with a cleaning component installed, it becomes difficult to ensure contact with the image holder, which may sometimes result in uneven image density. If it is softer than 45°, contact with the image holder can be ensured even without a cleaning component. However, to achieve lower hardness, methods such as increasing the amount of plasticizer added or using low-hardness materials such as silicone rubber can be considered. In the former case, plasticizer may sometimes leach out, causing problems such as image quality degradation; in the latter case, it may sometimes lead to a significant increase in cost.

[0161] Furthermore, the microhardness of the charged roller 10 can be measured using a hardness tester of type MD-1 manufactured by KOBUNSHI KEIKI CO.,LTD.

[0162] The above description, as an example of a live-line device, illustrates a live-line roller, but it is not limited to roller-shaped live-line devices. For example, brush-shaped, belt-shaped, or scraper-shaped live-line devices can be used.

[0163] [Electrophotographic photosensitive material]

[0164] The image forming apparatus according to this embodiment includes an electrophotographic photoreceptor (hereinafter also referred to as "photoreceptor"), which has a conductive substrate and a photosensitive layer disposed on the conductive substrate, and the outermost surface layer of the electrophotographic photoreceptor includes a charge transport material and a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B).

[0165] Figure 5 This is a partial cross-sectional view that schematically illustrates an example of the layer structure of the photoreceptor involved in this embodiment. Figure 5 The photoreceptor 10A shown has a stacked photosensitive layer. The photoreceptor 10A has a structure in which a lower coating layer 2, a charge generation layer 3, and a charge transport layer 4 are sequentially stacked on a conductive substrate 1. The charge generation layer 3 and the charge transport layer 4 constitute the photosensitive layer 5 (a so-called functionally separated photosensitive layer). The photoreceptor 10A may have an intermediate layer (not shown) between the lower coating layer 2 and the charge generation layer 3. The lower coating layer 2 may or may not be present.

[0166] Figure 6 This is a partial cross-sectional view that schematically illustrates another example of the layer structure of the photoreceptor involved in this embodiment. Figure 6 The photoreceptor 10B shown has a single-layer photosensitive layer. The photoreceptor 10B has a structure in which a lower coating layer 2 and a photosensitive layer 5 are sequentially stacked on a conductive substrate 1. The photoreceptor 10B may have an intermediate layer (not shown) between the lower coating layer 2 and the photosensitive layer 5. The lower coating layer 2 may or may not be present.

[0167] <Outermost layer>

[0168] The outermost layer of the photoreceptor comprises a charge transport material and a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B).

[0169] As the charge transport material contained in the outermost layer, examples include compounds that are the same as those contained in the charge transport layers described later, and the preferred compounds are also the same.

[0170] The polyaryl ester resin included in the outermost layer comprises a polyaryl ester resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B). In this invention, such polyaryl ester resin is referred to as polyaryl ester resin (PA).

[0171] The dicarboxylic acid unit (A) is the structural unit represented by the following formula (A).

[0172] [Chemical Formula 7]

[0173] Formula (A)

[0174] In equation (A), Ar A1 and Ar A2 Each is an aromatic ring that can have substituents, L A It is a single bond or a divalent linker, n A1 It can be 0, 1, or 2.

[0175] Ar A1 The aromatic ring can be any of a monocyclic or polycyclic aromatic ring. Examples of aromatic rings include benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings, with benzene rings and naphthalene rings being preferred.

[0176] Ar A1 The hydrogen atoms on the aromatic ring can be replaced by alkyl, aryl, aralkyl, alkoxy, aryloxy, halogen atoms, etc. As Ar... A1 When the aromatic ring is substituted, the substituents are preferably alkyl groups having 1 or more and 10 or less carbon atoms, aryl groups having 6 or more and 12 or less carbon atoms, and alkoxy groups having 1 or more and 6 or less carbon atoms.

[0177] Ar A2The aromatic ring can be any of a monocyclic or polycyclic aromatic ring. Examples of aromatic rings include benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings, with benzene rings and naphthalene rings being preferred.

[0178] Ar A2 The hydrogen atoms on the aromatic ring can be replaced by alkyl, aryl, aralkyl, alkoxy, aryloxy, halogen atoms, etc. As Ar... A2 When the aromatic ring is substituted, the substituents are preferably alkyl groups having 1 or more and 10 or less carbon atoms, aryl groups having 6 or more and 12 or less carbon atoms, and alkoxy groups having 1 or more and 6 or less carbon atoms.

[0179] When L A When the linking group is divalent, examples of divalent linking groups include oxygen atoms, sulfur atoms, and -C(Ra). 1 (Ra) 2 )-。 Here, Ra 1 and Ra 2 Ra is independently composed of hydrogen atoms, an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 1 With Ra 2 They can bond together to form cyclic alkyl groups.

[0180] Ra 1 and Ra 2 The alkyl group involving 1 or more and 10 or less carbon atoms can be any of straight-chain, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, and even more preferably 1 or 2.

[0181] Ra 1 and Ra 2 The aryl group involving 6 or more but less than 12 carbon atoms can be either monocyclic or polycyclic. The number of carbon atoms in the aryl group is preferably 6 or more but less than 10, and more preferably 6.

[0182] Ra 1 and Ra 2 The alkyl group in the aralkyl group with 7 or more and 20 or less carbon atoms can be any one of straight-chain, branched, or cyclic. The number of carbon atoms in the alkyl group of the aralkyl group with 7 or more and 20 or less carbon atoms is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or 2.

[0183] Ra 1 and Ra 2 The aryl group in the aralkyl group involving 7 or more and 20 or less carbon atoms can be any of a monocyclic or polycyclic ring. The number of carbon atoms in the aryl group is preferably 6 or more and 10 or less, more preferably 6.

[0184] The dicarboxylic acid unit (A) preferably comprises at least one selected from the group consisting of dicarboxylic acid units (A1) represented by formula (A1), dicarboxylic acid units (A2) represented by formula (A2), dicarboxylic acid units (A3) represented by formula (A3), dicarboxylic acid units (A4) represented by formula (A4), and dicarboxylic acid units (A5). More preferably, the dicarboxylic acid unit (A) comprises at least one selected from the group consisting of dicarboxylic acid units (A2), dicarboxylic acid units (A3), and dicarboxylic acid units (A4), and even more preferably comprises a dicarboxylic acid unit (A2).

[0185] [Chemical Formula 8]

[0186] Equation (A1)

[0187] In equation (A1), n 101 n is an integer greater than 0 and less than 4. 101 Ra 101 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0188] n 101 For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0189] [Chemical Formula 9]

[0190] Formula (A2)

[0191] In equation (A2), n 201 and n 202 Each of the following is an independent integer greater than 0 and less than 4, n 201 Ra 201 and n 202 Ra 202 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0192] n 201 For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0193] n 202 For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0194] [Chemical Formula 10]

[0195] Formula (A3)

[0196] In equation (A3), n 301 and n 302 Each of the following is an independent integer greater than 0 and less than 4, n 301 Ra 301 and n 302 Ra 302 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0197] n 301 For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0198] n 302 For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0199] [Chemical Formula 11]

[0200] Equation (A4)

[0201] In equation (A4), n 401 n is an integer greater than 0 and less than 6. 401 Ra 401 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0202] n 401 For example, it is preferably an integer greater than or equal to 0 and less than or equal to 4, more preferably 0, 1 or 2, and even more preferably 0.

[0203] [Chemical Formula 12]

[0204] Formula (A5)

[0205] In equation (A5), n 501 n 502 and n 503 Each of the following is an independent integer greater than 0 and less than 4, n 501 Ra 501 n 502 Ra 502 and n 503 Ra 503 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0206] n 501For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0207] n 502 For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0208] n 503 For example, 0, 1 or 2 is preferred, more preferably 0 or 1, and even more preferably 0.

[0209] Ra of formula (A1) 101 Ra of formula (A2) 201 and Ra 202 Ra of formula (A3) 301 and Ra 302 Ra of formula (A4) 401 And Ra of formula (A5) 501 Ra 502 and Ra 503 The specific form and preferred form are the same, therefore Ra will be described below. 101 Ra 201 Ra 202 Ra 301 Ra 302 Ra 401 Ra 501 Ra 502 and Ra 503 We will refer to them collectively as "Ra" for explanation.

[0210] The alkyl group involved in Ra with 1 or more and 10 or less carbon atoms can be any of straight-chain, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 or more and 6 or less, more preferably 1 or more and 4 or less, and even more preferably 1 or 2.

[0211] Examples of straight-chain alkyl groups with 1 or more but less than 10 carbon atoms include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, and n-decyl.

[0212] Examples of branched alkyl groups with 3 or more but less than 10 carbon atoms include isopropyl, isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, sec-hexyl, tert-hexyl, isohexyl, sec-heptyl, tert-heptyl, isooctyl, sec-octyl, tert-octyl, isononyl, sec-nonyl, tert-nonyl, isodel, sec-decyl, and tert-decyl.

[0213] Examples of cyclic alkyl groups with 3 or more but less than 10 carbon atoms include cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclononyl, cyclodecyl, and polycyclic (e.g., bicyclic, tricyclic, spirocyclic) alkyl groups formed by linking these monocyclic alkyl groups.

[0214] The aryl group involved in Ra, which has 6 or more but less than 12 carbon atoms, can be either monocyclic or polycyclic. The number of carbon atoms in the aryl group is preferably 6 or more but less than 10, and more preferably 6.

[0215] Examples of aryl groups with 6 or more but less than 12 carbon atoms include phenyl, biphenyl, 1-naphthyl, and 2-naphthyl.

[0216] The alkyl group in the alkoxy group involving Ra, which has 1 or more and 6 or less carbon atoms, can be any of the straight-chain, branched, and cyclic forms. The alkyl group in the alkoxy group, which has 1 or more and 4 or less carbon atoms, is preferably 1 or more and 3 or less, and even more preferably 1 or 2.

[0217] Examples of straight-chain alkoxy groups with 1 or more but less than 6 carbon atoms include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, and n-hexoxy.

[0218] Examples of branched alkoxy groups with 3 or more but less than 6 carbon atoms include isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentoxy, neopentoxy, tert-pentoxy, isohexoxy, sec-hexoxy, and tert-hexoxy.

[0219] Examples of cyclic alkoxy groups with 3 or more but less than 6 carbon atoms include cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexoxy.

[0220] The following examples of dicarboxylic acid units (A1-1) to (A1-9) are shown as specific examples of dicarboxylic acid units (A1). The dicarboxylic acid unit (A1) is not limited to these examples.

[0221] [Chemical Formula 13]

[0222]

[0223] The following examples of dicarboxylic acid units (A2-1) to (A2-3) are shown as specific examples of dicarboxylic acid units (A2). The dicarboxylic acid unit (A2) is not limited to these examples.

[0224] [Chemical Formula 14]

[0225]

[0226] Hereinafter, dicarboxylic acid units (A3-1) to (A3-2) are specifically shown as dicarboxylic acid units (A3). The dicarboxylic acid unit (A3) is not limited to these.

[0227] [Chemical Formula 15]

[0228]

[0229] Hereinafter, dicarboxylic acid units (A4-1) to (A4-3) are specifically shown as dicarboxylic acid units (A4). The dicarboxylic acid unit (A4) is not limited to these.

[0230] [Chemical Formula 16]

[0231]

[0232] Hereinafter, dicarboxylic acid units (A5-1) to (A5-4) are specifically shown as dicarboxylic acid units (A5). The dicarboxylic acid unit (A5) is not limited to these.

[0233] [Chemical Formula 17]

[0234] (A5-1)

[0235] (A5-2)

[0236] (A5-3)

[0237] (A5-4)

[0238] As a dicarboxylic acid unit (A), it is preferred to include at least one selected from the group consisting of (A1-1), (A1-7), (A2-3), (A3-2) and (A4-3) of the above specific examples, more preferably to include at least one selected from the group consisting of (A2-3), (A3-2) and (A4-3), and even more preferably to include at least (A2-3).

[0239] The dicarboxylic acid unit (A) contained in polyaryl ester resin (PA) can be one or more.

[0240] The mass percentage of dicarboxylic acid unit (A) in polyarylate resin (PA) is preferably 15% by mass or more and 60% by mass or less.

[0241] If the mass percentage of dicarboxylic acid unit (A) is 15% by mass or more, the wear resistance of the outermost layer is good. From this point of view, the mass percentage of dicarboxylic acid unit (A) is more preferably 20% by mass or more, and even more preferably 25% by mass or more.

[0242] If the mass percentage of dicarboxylic acid unit (A) is 60% by mass or less, the peeling of the outermost layer can be suppressed. From this point of view, the mass percentage of dicarboxylic acid unit (A) is more preferably 55% by mass or less, and even more preferably 50% by mass or less.

[0243] Polyaryl ester resins (PA) may contain dicarboxylic acid units other than the dicarboxylic acid unit (A). Examples of other dicarboxylic acid units include, for instance, aliphatic dicarboxylic acid units (e.g., oxalic acid, malonic acid, maleic acid, fumaric acid, citracic acid, itaconic acid, pentenic acid, succinic acid, alkenyl succinic acid, adipic acid, sebacic acid), alicyclic dicarboxylic acid units (e.g., cyclohexanedicarboxylic acid), and their lower (e.g., having 1 or more but less than 5 carbon atoms) alkyl ester units. The polyaryl ester resin (PA) may contain one or more of these dicarboxylic acid units.

[0244] The diol unit (B) is the structural unit represented by the following formula (B).

[0245] [Chemical Formula 18]

[0246] Formula (B)

[0247] In equation (B), Ar B1 and Ar B2 Each is an aromatic ring that can have substituents, L B It is a single bond, an oxygen atom, a sulfur atom, or -C(Rb) 1 (Rb) 2 )-,n B1 It can be 0, 1, or 2. Rb 1 and Rb 2 Rb is independently composed of hydrogen atoms, an alkyl group having 1 or more but less than 20 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 1 With Rb 2 They can bond together to form cyclic alkyl groups.

[0248] Ar B1 The aromatic ring can be any of a monocyclic or polycyclic aromatic ring. Examples of aromatic rings include benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings, with benzene rings and naphthalene rings being preferred.

[0249] Ar B1 The hydrogen atoms on the aromatic ring can be replaced by alkyl, aryl, aralkyl, alkoxy, aryloxy, halogen atoms, etc. As Ar... B1 When the aromatic ring is substituted, the substituents are preferably alkyl groups having 1 or more and 10 or less carbon atoms, aryl groups having 6 or more and 12 or less carbon atoms, and alkoxy groups having 1 or more and 6 or less carbon atoms.

[0250] Ar B2 The aromatic ring can be any of a monocyclic or polycyclic aromatic ring. Examples of aromatic rings include benzene rings, naphthalene rings, anthracene rings, and phenanthrene rings, with benzene rings and naphthalene rings being preferred.

[0251] Ar B2The hydrogen atoms on the aromatic ring can be replaced by alkyl, aryl, aralkyl, alkoxy, aryloxy, halogen atoms, etc. As Ar... B2 When the aromatic ring is substituted, the substituents are preferably alkyl groups having 1 or more and 10 or less carbon atoms, aryl groups having 6 or more and 12 or less carbon atoms, and alkoxy groups having 1 or more and 6 or less carbon atoms.

[0252] Rb 1 and Rb 2 The alkyl group involving 1 or more and 20 or less carbon atoms can be any of straight-chain, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 or more and 18 or less, more preferably 1 or more and 14 or less, and even more preferably 1 or more and 10 or less.

[0253] Rb 1 and Rb 2 The aryl group involving 6 or more but less than 12 carbon atoms can be either monocyclic or polycyclic. The number of carbon atoms in the aryl group is preferably 6 or more but less than 10, and more preferably 6.

[0254] Rb 1 and Rb 2 The alkyl group in the aralkyl group with 7 or more and 20 or less carbon atoms can be any one of straight-chain, branched, or cyclic. The number of carbon atoms in the alkyl group of the aralkyl group with 7 or more and 20 or less carbon atoms is preferably 1 or more and 4 or less, more preferably 1 or more and 3 or less, and even more preferably 1 or 2.

[0255] Rb 1 and Rb 2 The aryl group in the aralkyl group involving 7 or more and 20 or less carbon atoms can be any of a monocyclic or polycyclic ring. The number of carbon atoms in the aryl group is preferably 6 or more and 10 or less, more preferably 6.

[0256] The diol unit (B) preferably comprises at least one selected from the group consisting of diol unit (B1) represented by formula (B1), diol unit (B2) represented by formula (B2), diol unit (B3) represented by formula (B3), diol unit (B4) represented by formula (B4), diol unit (B5) represented by formula (B5), diol unit (B6) represented by formula (B6), diol unit (B7) represented by formula (B7) and diol unit (B8) represented by formula (B8).

[0257] The diol unit (B) more preferably comprises at least one selected from the group consisting of diol units (B1) represented by formula (B1), diol units (B2) represented by formula (B2), diol units (B4) represented by formula (B4), diol units (B5) represented by formula (B5), and diol units (B6) represented by formula (B6).

[0258] Further preferably, it comprises at least one selected from the group consisting of diol units (B1) represented by formula (B1), diol units (B2) represented by formula (B2), diol units (B5) represented by formula (B5), and diol units (B6) represented by formula (B6).

[0259] More preferably, it comprises at least one selected from the group consisting of diol units (B1) represented by formula (B1), diol units (B2) represented by formula (B2), and diol units (B6) represented by formula (B6).

[0260] Most preferably, it comprises at least one of the groups consisting of diol units (B1) represented by formula (B1) and diol units (B2) represented by formula (B2).

[0261] [Chemical Formula 19]

[0262] Formula (B1)

[0263] In equation (B1), Rb 101 Branched alkyl groups with 4 or more but less than 20 carbon atoms, Rb 201 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 401 、Rb 501 、Rb 801 and Rb 901 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0264] Rb 101 The branched alkyl group involving 4 or more and 20 or less carbon atoms preferably has 4 or more and 16 or less carbon atoms, more preferably 4 or more and 12 or less, and even more preferably 4 or more and 8 or less. As Rb 101 Specific examples include isobutyl, sec-butyl, tert-butyl, isopentyl, neopentyl, tert-pentyl, isohexyl, sec-hexyl, tert-hexyl, isohexyl, sec-heptyl, tert-heptyl, isooctyl, sec-octyl, tert-octyl, isononyl, sec-nonyl, tert-nonyl, isodel, sec-decyl, tert-decyl, isododecyl, sec-dodecyl, tert-dodecyl, tert-tetradecyl, tert-pentadecanyl, etc.

[0265] [Chemical Formula 20]

[0266] Formula (B2)

[0267] In equation (B2), Rb 102 Rb is a straight-chain alkyl group with 4 or more but less than 20 carbon atoms. 202 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 402 、Rb 502 、Rb 802 and Rb 902 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0268] Rb 102 The linear alkyl group involving 4 or more and 20 carbon atoms preferably has 4 or more and 16 or less carbon atoms, more preferably 4 or more and 12 or less, and even more preferably 4 or more and 8 or less. As Rb 102 Specific examples include n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl, n-decyl, n-undecyl, n-dodecyl, tridecyl, n-tetradecyl, n-pentadecanyl, n-heptadecyl, n-octadecyl, n-nonadecanyl, n-eicosyl, etc.

[0269] [Chemical Formula 21]

[0270] Formula (B3)

[0271] In equation (B3), Rb 113 and Rb 213 Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where d is an integer between 7 and 15, and Rb 403 、Rb 503 、Rb 803 and Rb 903 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0272] Rb 113 and Rb 213 The number of carbon atoms in the straight-chain alkyl group involving 1 or more and 3 or less is preferably 1 or 2, more preferably 1. Specific examples of this group include methyl, ethyl, and n-propyl.

[0273] Rb 113 and Rb 213The alkyl group in the alkoxy group with 1 or more and 4 or fewer carbon atoms can be any of the following: linear, branched, and cyclic. The alkyl group in the alkoxy group with 1 or more and 4 or fewer carbon atoms preferably has 1 or more and 3 or fewer carbon atoms, more preferably 1 or 2, and even more preferably 1. Specific examples of this group include methoxy, ethoxy, n-propoxy, n-butoxy, isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, cyclopropoxy, and cyclobutoxy.

[0274] As Rb 113 and Rb 213 The halogen atoms involved can be fluorine, chlorine, bromine, and iodine.

[0275] [Chemical Formula 22]

[0276] Equation (B4)

[0277] In equation (B4), Rb 104 and Rb 204 Each is independently an alkyl group having 1 or more but less than 3 carbon atoms, Rb 404 、Rb 504 、Rb 804 and Rb 904 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0278] Rb 104 The alkyl group involving 1 to 3 carbon atoms can be linear, branched, or cyclic. The alkyl group preferably has 1 or 2 carbon atoms, more preferably 1. As Rb 104 Specific examples include methyl, ethyl, n-propyl, isopropyl, and cyclopropyl.

[0279] [Chemical Formula 23]

[0280] Formula (B5)

[0281] In equation (B5), Ar 105 Rb is an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 205 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 405 、Rb 505 、Rb 805 and Rb 905 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0282] Ar105 The aryl group involving 6 or more but less than 12 carbon atoms can be either monocyclic or polycyclic. The number of carbon atoms in the aryl group is preferably 6 or more but less than 10, and more preferably 6.

[0283] Ar 105 The alkyl group in the aralkyl group having 7 or more and 20 or fewer carbon atoms can be any of straight-chain, branched, or cyclic. The alkyl group in the aralkyl group having 7 or more and 20 or fewer carbon atoms preferably has 1 or more and 4 or fewer carbon atoms, more preferably 1 or more and 3 or fewer carbon atoms, and even more preferably 1 or 2 carbon atoms. 105 The aryl group in the aralkyl group with 7 or more and 20 or less carbon atoms can be either monocyclic or polycyclic. The number of carbon atoms in the aryl group is preferably 6 or more and 10 or less, more preferably 6. Examples of aralkyl groups with 7 or more and 20 or less carbon atoms include benzyl, phenylethyl, phenylpropyl, 4-phenylbutyl, phenylpentyl, phenylhexyl, phenylheptyl, phenyloctyl, phenylnonyl, naphthylmethyl, naphthylethyl, anthraceneylmethyl, and phenyl-cyclopentylmethyl.

[0284] [Chemical Formula 24]

[0285] Formula (B6)

[0286] In equation (B6), Rb 116 and Rb 216 Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where e is an integer of 4 or more but less than 6, and Rb 406 、Rb 506 、Rb 806 and Rb 906 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0287] Rb 116 and Rb 216 The number of carbon atoms in the straight-chain alkyl group involving 1 or more and 3 or less is preferably 1 or 2, more preferably 1. Specific examples of this group include methyl, ethyl, and n-propyl.

[0288] Rb 116 and Rb 216The alkyl group in the alkoxy group with 1 or more and 4 or fewer carbon atoms can be any of the following: linear, branched, and cyclic. The alkyl group in the alkoxy group with 1 or more and 4 or fewer carbon atoms preferably has 1 or more and 3 or fewer carbon atoms, more preferably 1 or 2, and even more preferably 1. Specific examples of this group include methoxy, ethoxy, n-propoxy, n-butoxy, isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, cyclopropoxy, and cyclobutoxy.

[0289] As Rb 116 and Rb 216 The halogen atoms involved can be fluorine, chlorine, bromine, and iodine.

[0290] [Chemical Formula 25]

[0291] Formula (B7)

[0292] In equation (B7), Rb 407 、Rb 507 、Rb 807 and Rb 907 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0293] [Chemical Formula 26]

[0294] Formula (B8)

[0295] In equation (B8), Rb 408 、Rb 508 、Rb 808 and Rb 908 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0296] Rb in equation (B1) 201 Rb in equation (B2) 202 Rb in equation (B4) 204 and Rb of formula (B5) 205 The specific form and preferred form are the same, therefore, Rb will be referred to below. 201 、Rb 202 、Rb 204 and Rb 205 Collectively referred to as "Rb" 200 To explain.

[0297] Rb 200The alkyl group involving 1 or more but less than 3 carbon atoms can be any of the following: straight-chain, branched, or cyclic. The number of carbon atoms in the alkyl group is preferably 1 or 2, and more preferably 1.

[0298] Examples of alkyl groups with 1 or more but less than 3 carbon atoms include methyl, ethyl, n-propyl, isopropyl, and cyclopropyl.

[0299] Rb in equation (B1) 401 Rb in equation (B2) 402 Rb in equation (B3) 403 Rb in equation (B4) 404 Rb in equation (B5) 405 Rb in equation (B6) 406 Rb in equation (B7) 407 and Rb of formula (B8) 408 The specific form and preferred form are the same, therefore, Rb will be referred to below. 401 、Rb 402 、Rb 403 、Rb 404 、Rb 405 、Rb 406 、Rb 407 and Rb 408 Collectively referred to as "Rb" 400 To explain.

[0300] Rb 400 The alkyl group involving 1 or more and 4 or less carbon atoms can be any of the following: straight-chain, branched, and cyclic. The alkyl group preferably has 1 or more and 3 or less carbon atoms, more preferably 1 or 2, and even more preferably 1.

[0301] Examples of straight-chain alkyl groups with 1 or more but less than 4 carbon atoms include methyl, ethyl, n-propyl, and n-butyl.

[0302] Examples of branched alkyl groups with 3 or 4 carbon atoms include isopropyl, isobutyl, sec-butyl, and tert-butyl.

[0303] Examples of cyclic alkyl groups with 3 or 4 carbon atoms include cyclopropyl and cyclobutyl.

[0304] Rb 400 The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms can be any of the straight-chain, branched, and cyclic forms. The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms preferably has 1 or more and 4 or less carbon atoms, more preferably 1 or more and 3 or less carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0305] Examples of straight-chain alkoxy groups with 1 or more but less than 6 carbon atoms include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, and n-hexoxy.

[0306] Examples of branched alkoxy groups with 3 or more but less than 6 carbon atoms include isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentoxy, neopentoxy, tert-pentoxy, isohexoxy, sec-hexoxy, and tert-hexoxy.

[0307] Examples of cyclic alkoxy groups with 3 or more but less than 6 carbon atoms include cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexoxy.

[0308] As Rb 400 The halogen atoms involved can be fluorine, chlorine, bromine, and iodine.

[0309] Rb in equation (B1) 501 Rb in equation (B2) 502 Rb in equation (B3) 503 Rb in equation (B4) 504 Rb in equation (B5) 505 Rb in equation (B6) 506 Rb in equation (B7) 507 and Rb of formula (B8) 508 The specific form and preferred form are the same, therefore, Rb will be referred to below. 501 、Rb 502 、Rb 503 、Rb 504 、Rb 505 、Rb 506 、Rb 507 and Rb 508 Collectively referred to as "Rb" 500 To explain.

[0310] Rb 500 The alkyl group involving 1 or more and 4 or less carbon atoms can be any of the following: straight-chain, branched, and cyclic. The alkyl group preferably has 1 or more and 3 or less carbon atoms, more preferably 1 or 2, and even more preferably 1.

[0311] Examples of straight-chain alkyl groups with 1 or more but less than 4 carbon atoms include methyl, ethyl, n-propyl, and n-butyl.

[0312] Examples of branched alkyl groups with 3 or 4 carbon atoms include isopropyl, isobutyl, sec-butyl, and tert-butyl.

[0313] Examples of cyclic alkyl groups with 3 or 4 carbon atoms include cyclopropyl and cyclobutyl.

[0314] Rb 500The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms can be any of the straight-chain, branched, and cyclic forms. The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms preferably has 1 or more and 4 or less carbon atoms, more preferably 1 or more and 3 or less carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0315] Examples of straight-chain alkoxy groups with 1 or more but less than 6 carbon atoms include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, and n-hexoxy.

[0316] Examples of branched alkoxy groups with 3 or more but less than 6 carbon atoms include isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentoxy, neopentoxy, tert-pentoxy, isohexoxy, sec-hexoxy, and tert-hexoxy.

[0317] Examples of cyclic alkoxy groups with 3 or more but less than 6 carbon atoms include cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexoxy.

[0318] As Rb 500 The halogen atoms involved can be fluorine, chlorine, bromine, and iodine.

[0319] Rb in equation (B1) 801 Rb in equation (B2) 802 Rb in equation (B3) 803 Rb in equation (B4) 804 Rb in equation (B5) 805 Rb in equation (B6) 806 Rb in equation (B7) 807 and Rb of formula (B8) 808 The specific form and preferred form are the same, therefore, Rb will be referred to below. 801 、Rb 802 、Rb 803 、Rb 804 、Rb 805 、Rb 806 、Rb 807 and Rb 808 Collectively referred to as "Rb" 800 To explain.

[0320] Rb 800 The alkyl group involving 1 or more and 4 or less carbon atoms can be any of the following: straight-chain, branched, and cyclic. The alkyl group preferably has 1 or more and 3 or less carbon atoms, more preferably 1 or 2, and even more preferably 1.

[0321] Examples of straight-chain alkyl groups with 1 or more but less than 4 carbon atoms include methyl, ethyl, n-propyl, and n-butyl.

[0322] Examples of branched alkyl groups with 3 or 4 carbon atoms include isopropyl, isobutyl, sec-butyl, and tert-butyl.

[0323] Examples of cyclic alkyl groups with 3 or 4 carbon atoms include cyclopropyl and cyclobutyl.

[0324] Rb 800 The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms can be any of the straight-chain, branched, and cyclic forms. The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms preferably has 1 or more and 4 or less carbon atoms, more preferably 1 or more and 3 or less carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0325] Examples of straight-chain alkoxy groups with 1 or more but less than 6 carbon atoms include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, and n-hexoxy.

[0326] Examples of branched alkoxy groups with 3 or more but less than 6 carbon atoms include isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentoxy, neopentoxy, tert-pentoxy, isohexoxy, sec-hexoxy, and tert-hexoxy.

[0327] Examples of cyclic alkoxy groups with 3 or more but less than 6 carbon atoms include cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexoxy.

[0328] As Rb 800 The halogen atoms involved can be fluorine, chlorine, bromine, and iodine.

[0329] Rb in equation (B1) 901 Rb in equation (B2) 902 Rb in equation (B3) 903 Rb in equation (B4) 904 Rb in equation (B5) 905 Rb in equation (B6) 906 Rb in equation (B7) 907 and Rb of formula (B8) 908 The specific form and preferred form are the same, therefore, Rb will be referred to below. 901 、Rb 902 、Rb 903 、Rb 904 、Rb 905 、Rb 906 、Rb 907 and Rb 908 Collectively referred to as "Rb" 900 To explain.

[0330] Rb 900The alkyl group involving 1 or more and 4 or less carbon atoms can be any of the following: straight-chain, branched, and cyclic. The alkyl group preferably has 1 or more and 3 or less carbon atoms, more preferably 1 or 2, and even more preferably 1.

[0331] Examples of straight-chain alkyl groups with 1 or more but less than 4 carbon atoms include methyl, ethyl, n-propyl, and n-butyl.

[0332] Examples of branched alkyl groups with 3 or 4 carbon atoms include isopropyl, isobutyl, sec-butyl, and tert-butyl.

[0333] Examples of cyclic alkyl groups with 3 or 4 carbon atoms include cyclopropyl and cyclobutyl.

[0334] Rb 900 The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms can be any of the straight-chain, branched, and cyclic forms. The alkyl group in the alkoxy group with 1 or more and 6 or less carbon atoms preferably has 1 or more and 4 or less carbon atoms, more preferably 1 or more and 3 or less carbon atoms, and even more preferably 1 or 2 carbon atoms.

[0335] Examples of straight-chain alkoxy groups with 1 or more but less than 6 carbon atoms include methoxy, ethoxy, n-propoxy, n-butoxy, n-pentoxy, and n-hexoxy.

[0336] Examples of branched alkoxy groups with 3 or more but less than 6 carbon atoms include isopropoxy, isobutoxy, sec-butoxy, tert-butoxy, isopentoxy, neopentoxy, tert-pentoxy, isohexoxy, sec-hexoxy, and tert-hexoxy.

[0337] Examples of cyclic alkoxy groups with 3 or more but less than 6 carbon atoms include cyclopropoxy, cyclobutoxy, cyclopentoxy, and cyclohexoxy.

[0338] As Rb 900 The halogen atoms involved can be fluorine, chlorine, bromine, and iodine.

[0339] Hereinafter, diol units (B1-1) to (B1-6) are specifically shown as diol units (B1). The diol unit (B1) is not limited to this.

[0340] [Chemical Formula 27]

[0341]

[0342] Hereinafter, diol units (B2-1) to (B2-11) are specifically shown as diol units (B2). The diol unit (B2) is not limited to these.

[0343] [Chemical Formula 28]

[0344]

[0345] Hereinafter, diol units (B3-1) to (B3-4) are specifically shown as diol units (B3). The diol unit (B3) is not limited to these.

[0346] [Chemical Formula 29]

[0347]

[0348] Hereinafter, diol units (B4-1) to (B4-7) are specifically shown as diol units (B4). The diol unit (B4) is not limited to this.

[0349] [Chemical Formula 30]

[0350]

[0351] Hereinafter, diol units (B5-1) to (B5-6) are specifically shown as diol units (B5). The diol unit (B5) is not limited to these.

[0352] [Chemical Formula 31]

[0353]

[0354] Hereinafter, diol units (B6-1) to (B6-4) are specifically shown as diol units (B6). The diol unit (B6) is not limited to these.

[0355] [Chemical Formula 32]

[0356]

[0357] Hereinafter, diol units (B7-1) to (B7-3) are specifically shown as diol units (B7). The diol unit (B7) is not limited to these.

[0358] [Chemical Formula 33]

[0359]

[0360] Hereinafter, diol units (B8-1) to (B8-3) are specifically shown as diol units (B8). The diol unit (B8) is not limited to these.

[0361] [Chemical Formula 34]

[0362]

[0363] The diol unit (B) contained in polyaryl ester resin (PA) can be one or more.

[0364] The mass percentage of the diol unit (B) in the polyaryl ester resin (PA) is preferably 25% by mass or more and 80% by mass or less.

[0365] If the mass percentage of the diol unit (B) is 25% by mass or more, the peeling of the outermost layer can be suppressed. From this point of view, the mass percentage of the diol unit (B) is more preferably 30% by mass or more, and even more preferably 35% by mass or more.

[0366] If the mass percentage of the diol unit (B) is 80% by mass or less, the wear resistance can be improved by maintaining the solubility relative to the coating liquid used to form the outermost surface layer. From this point of view, the mass percentage of the diol unit (B) is more preferably 75% by mass or less, and even more preferably 70% by mass or less.

[0367] Polyaryl ester resins (PA) may contain diol units other than the diol unit (B). Examples of other diol units include, for instance, aliphatic diols (e.g., ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, hexanediol, neopentyl glycol) and alicyclic diols (e.g., cyclohexanediol, cyclohexanediol, hydrogenated bisphenol A). The polyaryl ester resin (PA) may contain one or more of these diol units.

[0368] The ends of polyarylate resins (PA) can be sealed or modified by end-capping agents or molecular weight regulators used during manufacturing. Examples of end-capping agents or molecular weight regulators include monohydric phenols, monohydric acyl chlorides, monohydric alcohols, and monohydric carboxylic acids.

[0369] Examples of monohydric phenols include phenol, o-cresol, m-cresol, p-cresol, o-ethylphenol, m-ethylphenol, p-ethylphenol, o-propylphenol, m-propylphenol, p-propylphenol, o-tert-butylphenol, m-tert-butylphenol, p-tert-butylphenol, pentylphenol, hexylphenol, octylphenol, nonylphenol, 2,6-dimethylphenol derivatives, 2-methylphenol derivatives, o-phenylphenol, m-phenylphenol, p-phenylphenol, and o-methoxyphenol. Phenol, m-methoxyphenol, p-methoxyphenol, 2,3,5-trimethylphenol, 2,3,6-trimethylphenol, 2,3-xylenol, 2,4-xylenol, 2,5-xylenol, 2,6-xylenol, 3,4-xylenol, 3,5-xylenol, 2-phenyl-2-(4-hydroxyphenyl)propane, 2-phenyl-2-(2-hydroxyphenyl)propane, 2-phenyl-2-(3-hydroxyphenyl)propane.

[0370] Examples of monoacyl chlorides include benzoyl chloride, benzoyl chloride, methanesulfonyl chloride, phenyl chloroformate, acetyl chloride, butyryl chloride, octanoyl chloride, benzenesulfonyl chloride, benzenesulfinyl chloride, sulfinyl chloride, phenylphosphonic chloride, and their substituted derivatives, which are all functional acid acyl halides.

[0371] Examples of monohydric alcohols include methanol, ethanol, n-propanol, isopropanol, n-butanol, 2-butanol, pentanol, hexanol, dodecyl alcohol, stearyl alcohol, benzyl alcohol, and phenylethanol.

[0372] Examples of monocarboxylic acids include acetic acid, propionic acid, octanoic acid, cyclohexanecarboxylic acid, benzoic acid, methylbenzoic acid, phenylacetic acid, p-tert-butylbenzoic acid, and p-methoxyphenylacetic acid.

[0373] The weight-average molecular weight of the polyaryl ester resin (PA) is preferably 30,000 or more and 300,000 or less, more preferably 40,000 or more and 250,000 or less, and even more preferably 50,000 or more and 200,000 or less.

[0374] The molecular weight of polyaryl ester resin (PA) is the molecular weight converted from polystyrene as determined by GPC (gel permeation chromatography). Tetrahydrofuran is used as the eluent in GPC.

[0375] Polyaryl ester resins (PA) are obtained by conventional methods involving the polycondensation of monomers containing dicarboxylic acid units (A), monomers containing diol units (B), and other monomers as needed. Examples of monomer polycondensation methods include interfacial polymerization, solution polymerization, and melt polymerization. Interfacial polymerization is a polymerization method that obtains polyesters by mixing a dicarboxyl halogen dissolved in a water-incompatible organic solvent and a diol dissolved in an alkaline aqueous solution. References related to interfacial polymerization include WMEARECKSON, J. Poly. Sci., XL399, 1959, Japanese Patent Publication No. 40-1959. Compared to solution polymerization, interfacial polymerization has a faster reaction rate, thus suppressing the hydrolysis of the dicarboxyl halogen, resulting in the production of high molecular weight polyaryl ester resins (PA).

[0376] Other resins included in the outermost layer include polyarylene resins other than polyarylene resins (PA), polycarbonate resins, polyester resins other than polyarylene resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl acetate resins, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, silicone resins, silicone alkyd resins, phenolic-formaldehyde resins, styrene-alkyd resins, poly-N-vinylcarbazole, and polysilanes. Two or more of these resins can be used in any combination.

[0377] From the viewpoint of wear resistance, the resin contained in the outermost layer is preferably composed of, for example, polyarylate resin and polycarbonate resin. Furthermore, the morphology of the polyarylate resin and polycarbonate resin is also preferred from the viewpoint of forming a fine phase-separated structure in the outermost layer.

[0378] From the viewpoint of forming a fine phase separation structure in the outermost layer, the proportion of polyaryl ester resin in the total amount of polyaryl ester resin and polycarbonate resin contained in the outermost layer of the photoreceptor is preferably 20% by mass or more and 80% by mass or less, more preferably 25% by mass or more and 75% by mass or less, and even more preferably 30% by mass or more and 70% by mass or less.

[0379] Polyaryl ester resins improve the wear resistance of the outermost layer by stacking aromatic rings, which binds the resin molecules together through intermolecular forces. For example, condensation polymers of bisphenols and aromatic dicarboxylic acids are preferred polyaryl ester resins. Examples of polyaryl ester resin forms include polyaryl ester resins (PA) described later.

[0380] As a polycarbonate resin, a polycarbonate resin having a continuous structure of aromatic rings is preferred, for example. This polycarbonate resin, through the stacking of aromatic rings, allows resin molecules to be bonded together by intermolecular forces, thereby improving the wear resistance of the outermost layer. For example, as a preferred form of polycarbonate resin, specifically, the polycarbonate resin disclosed in Japanese Patent Application Publication No. 2023-121553 can be cited. For example, as a more preferred form of polycarbonate resin, the polycarbonate resin used in the embodiments described later can be cited.

[0381] As a combination of polyarylate resin and polycarbonate resin, it is preferred, for example, to be a combination of resins that both have structural units containing biphenyl as represented by the following formula (BP).

[0382] [Chemical Formula 35]

[0383] Formula (BP)

[0384] In equation (BP), j is an integer greater than 0 and less than 4, and j are R... 1 Each is independently methyl or ethyl, k is an integer greater than or equal to 0 and less than or equal to 4, and k R's are independent of each other. 2 Each can be methyl or ethyl, independently.

[0385] The biphenyl represented by formula (BP) can be the entire structure obtained by removing ester bonds (-C(=O)O-) or carbonate bonds (-OC(=O)O-) from the structural unit containing the biphenyl represented by formula (BP), or it can be a part of the structure. In other words, the right and left ends of the biphenyl represented by formula (BP) can be directly bonded to ester bonds or carbonate bonds independently, or they can be bonded to ester bonds or carbonate bonds through other atoms or groups.

[0386] j is an integer greater than or equal to 0 and less than 4, preferably an integer greater than or equal to 0 and less than 3, more preferably an integer greater than or equal to 0 and less than 2, further preferably 0 or 1, and especially preferably 0.

[0387] When j is an integer greater than or equal to 1, j R 1 Each is independently methyl or ethyl, for example preferably methyl.

[0388] k is an integer greater than or equal to 0 and less than 4, preferably an integer greater than or equal to 0 and less than 3, more preferably an integer greater than or equal to 0 and less than 2, further preferably 0 or 1, and especially preferably 0.

[0389] When k is an integer greater than or equal to 1, k R 2 Each is independently methyl or ethyl, for example preferably methyl.

[0390] The biphenyl represented by formula (BP) is preferably linked at a 4,4'-biphenyl position in the main chain.

[0391] As a combination of polyaryl ester resin and polycarbonate resin, a combination of polyaryl ester resin having at least one of dicarboxylic acid unit (A2-3) and diol unit (B7-1) and polycarbonate resin having structural unit (Cb7-1) is particularly preferred.

[0392] [Chemical Formula 36]

[0393]

[0394] The outermost layer preferably also contains phenolic compounds.

[0395] Examples of phenolic compounds contained in the outermost layer include phenol, cresol, catechol, resorcinol, hydroquinone, naphthol, and bisphenols (bisphenol A, AP, AF, B, BP, C, C2, E, F, G, M, S, P, PH, TMC, Z). A single phenolic compound can be used, or two or more can be used simultaneously.

[0396] Hindered phenolic compounds can also be cited as phenolic compounds included in the outermost layer. From the viewpoint of inhibiting oxidative degradation of the outermost layer, the phenolic compounds included in the outermost layer preferably include, for example, hindered phenolic compounds. Generally, hindered phenolic compounds are compounds in which at least one of the ortho positions of the hydroxyl groups of phenol is substituted with a bulky group, and they are known to exert an antioxidant effect on the composition.

[0397] Examples of hindered phenolic compounds include the following compounds.

[0398] Alkylated monophenol compounds and their derivatives: for example, 2,6-di-tert-butyl-4-methylphenol, 2,6-di-tert-butyl-4-ethylphenol, octyl-3,5-di-tert-butyl-4-hydroxy-hydroxycinnamate.

[0399] Alkylated hydroquinone compounds and their derivatives: for example, 2,5-di-tert-butylhydroquinone, 2,5-di-tert-pentylhydroquinone

[0400] Alkyl thiocresol compounds and their derivatives: for example, 2,4-dioctylthiomethyl-6-tert-butylphenol, 2,4-dioctylthiomethyl-6-methylphenol, 2,4-dioctylthiomethyl-6-ethylphenol, 2,6-docodecylthiomethyl-4-nonylphenol

[0401] Alkylene bisphenol compounds and their derivatives: for example, 4,4'-butyride bis(6-tert-butyl-3-methylphenol), 2,2'-methylene bis(6-tert-butyl-4-methylphenol), 2,2'-methylene bis(6-tert-butyl-4-ethylphenol), 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 3,9-bis[2-[3-(3-tert-butyl-4-hydroxy-5-methylphenyl)propionyloxy]-1,1-dimethylethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane

[0402] Commercially available hindered phenolic compounds include ADEKA CORPORATION's "ADKSTAB AO-80", "ADKSTAB AO-60", "ADKSTAB AO-50", "ADKSTAB AO-40", "ADKSTAB AO-30", "ADKSTAB AO-20", and "ADKSTAB AO-330"; BASF Japan Ltd.'s "Irganox 1010", "Irganox 245", "Irganox 1076", and "Irganox 1520"; and Sumitomo Chemical Co., Ltd.'s "Sumilizer GA-80", "Sumilizer GM", and "Sumilizer GS".

[0403] Hindered phenolic compounds can be used alone or in combination with two or more compounds.

[0404] From the viewpoint of promoting phase separation of two or more resins during the formation of the outermost layer and forming a fine phase separation structure in the outermost layer, the content of phenolic compounds contained in the outermost layer is preferably, for example, 0.1% by mass or more and 20% by mass or less, more preferably 0.5% by mass or more and 10% by mass or less, and even more preferably 1% by mass or more and 5% by mass or less, relative to the total mass of the outermost layer.

[0405] In the outermost layer of the photoreceptor, the proportion of fluoropolymer particles in the layer is preferably 5% by mass or less, more preferably 1% by mass or less, and even more preferably 0% by mass (i.e., it does not contain fluoropolymer particles).

[0406] Given the high likelihood of stricter restrictions on the manufacture and use of organofluorine compounds in the future, the content of fluoropolymer particles is preferably within the range described above.

[0407] The thickness of the outermost layer can be set according to the function of that layer.

[0408] When the charge transport layer is the outermost layer, the thickness of the outermost layer is preferably 5 μm or more and 50 μm or less, more preferably 8 μm or more and 45 μm or less, and even more preferably 10 μm or more and 40 μm or less.

[0409] When the single-layer photosensitive layer is the outermost layer, the thickness of the outermost layer is preferably 5 μm or more and 50 μm or less, more preferably 8 μm or more and 45 μm or less, and even more preferably 10 μm or more and 40 μm or less.

[0410] The method for forming the outermost layer is the same as the method for forming the charge transport layer and the method for forming the monolayer photosensitive layer, which will be described later.

[0411] The following is a detailed description of each layer of the photoreceptor.

[0412] <Conductive substrate>

[0413] Examples of conductive substrates include metal plates, metal drums, and metal strips containing metals (aluminum, copper, zinc, chromium, nickel, molybdenum, vanadium, indium, gold, platinum, etc.) or alloys (stainless steel, etc.). Furthermore, examples of conductive substrates include conductive compounds (e.g., conductive polymers, indium oxide, etc.); paper coated, vapor-deposited, or laminated with metals (e.g., aluminum, palladium, gold, etc.) or alloys; resin films; and tapes. Here, "conductivity" refers to a volume resistivity of less than 1 × 10⁻⁶. 13 Ω·cm.

[0414] When an electrophotographic photosensitive material is used in a laser printer, the surface of the conductive substrate is preferably roughened to 0.04 μm or more and 0.5 μm or less, based on the centerline average roughness Ra, in order to suppress interference fringes generated when the laser beam is irradiated. When incoherent light is used as the light source, roughening to prevent interference fringes is not particularly necessary, but suppressing the generation of defects caused by unevenness on the conductive substrate surface is beneficial for extending the lifespan.

[0415] Examples of roughening methods include wet grinding, which involves suspending an abrasive in water and spraying it onto a conductive substrate; centerless grinding, which involves pressing a conductive substrate onto a rotating grinding wheel and continuously grinding it; and anodizing.

[0416] As a roughening method, another example is a method in which conductive or semi-conductive powder is dispersed in a resin to form a layer on the surface of the conductive substrate without roughening the surface of the conductive substrate, and roughening is achieved by the particles dispersed in the layer.

[0417] Anodizing-based roughening processes involve anolysing a conductive metallic substrate (e.g., aluminum) in an electrolyte solution, thereby forming an oxide film on the surface of the conductive substrate. Examples of electrolyte solutions include sulfuric acid and oxalic acid. However, the porous anodic oxide film formed by anodizing is chemically active in its original state, easily contaminated, and exhibits significant resistance variations due to environmental factors. Therefore, it is preferable, for example, to perform a sealing treatment on the porous anodic oxide film, blocking the micropores of the oxide film by volume expansion caused by water and reaction in pressurized steam or boiling water (with the addition of metal salts such as nickel), thereby transforming it into a more stable hydrated oxide.

[0418] The thickness of the anodic oxide film is preferably 0.3 μm or more and 15 μm or less. If the film thickness is within the above range, there is a tendency for it to exert a barrier effect relative to the implantation, and there is a tendency for the rise in residual potential caused by repeated use to be suppressed.

[0419] Conductive substrates can be treated with acidic solutions or boehmite.

[0420] The treatment based on the acidic treatment solution is carried out, for example, as follows. First, an acidic treatment solution containing phosphoric acid, chromic acid, and hydrofluoric acid is prepared. The proportions of phosphoric acid, chromic acid, and hydrofluoric acid in the acidic treatment solution are, for example, phosphoric acid in the range of 10% by mass or more and 11% by mass or less, chromic acid in the range of 3% by mass or more and 5% by mass or less, and hydrofluoric acid in the range of 0.5% by mass or more and 2% by mass or less. The concentration of their total acid content is preferably in the range of 13.5% by mass or more and 18% by mass or less. The treatment temperature is preferably, for example, 42°C or more and 48°C or less. The film thickness is preferably, for example, 0.3 μm or more and 15 μm or less.

[0421] Boehmite treatment can be performed, for example, by immersion in pure water at a temperature above 90°C and below 100°C for 5 to 60 minutes, or by contact in heated steam at a temperature above 90°C and below 120°C for 5 to 60 minutes. The film thickness is preferably, for example, 0.1 μm or more and 5 μm or less. Further anodizing can be performed using electrolyte solutions with low film solubility, such as adipic acid, boric acid, borates, phosphates, phthalates, maleates, benzoates, tartrates, and citrates.

[0422] <Undercoat>

[0423] The undercoat layer may be, for example, a layer containing inorganic particles and a binding resin.

[0424] As inorganic particles, for example, the resistance (volume resistivity) of powder is 1×10⁻⁶. 2 Ω·cm or more and 1×10 11 Inorganic particles below Ω·cm.

[0425] Among them, inorganic particles having the above-mentioned resistance values ​​are preferably metal oxide particles such as tin oxide particles, titanium oxide particles, zinc oxide particles, and zirconium oxide particles, and zinc oxide particles are particularly preferred.

[0426] The specific surface area of ​​inorganic particles based on the BET method is preferably, for example, 10 m². 2 / g or more.

[0427] The volume average particle size of the inorganic particles is preferably 50 nm or more and 2000 nm or less (preferably 60 nm or more and 1000 nm or less).

[0428] The content of inorganic particles, relative to the bonding resin, is preferably 10% by mass or more and 80% by mass or less, more preferably 40% by mass or more and 80% by mass or less.

[0429] Inorganic particles can be used for surface treatment. Two or more types of inorganic particles with different surface treatments or different particle sizes can be mixed together.

[0430] Examples of surface treatment agents include silane coupling agents, titanate coupling agents, aluminum coupling agents, and surfactants. In particular, silane coupling agents are preferred, and silane coupling agents having an amino group are more preferred.

[0431] Examples of amino-containing silane coupling agents include 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, and N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, but are not limited to these.

[0432] Two or more silane coupling agents can be used in combination. For example, an amino-containing silane coupling agent can be used in combination with other silane coupling agents. Other silane coupling agents include, but are not limited to, vinyltrimethoxysilane, 3-methacryloyloxypropyltris(2-methoxyethoxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-chloropropyltrimethoxysilane.

[0433] Surface treatment methods based on surface treatment agents can be any known method, including either dry or wet methods.

[0434] The amount of surface treatment agent relative to the inorganic particles is preferably 0.5% by mass or more and 10% by mass or less.

[0435] From the viewpoint of improving the long-term stability of electrical properties and carrier blocking properties, the lower coating preferably contains an electron acceptor compound (acceptor compound) together with the inorganic particles.

[0436] Examples of electron-accepting compounds include compounds with anthraquinone structures; quinones such as chloroquinone and tetrabromo-p-benzoquinone; dimethyl tetracyano-p-benzodiquinone; fluorenones such as 2,4,7-trinitrofluorenone and 2,4,5,7-tetranitro-9-fluorenone; oxadiazoles such as 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, 2,5-bis(4-naphthyl)-1,3,4-oxadiazole, and 2,5-bis(4-diethylaminophenyl)-1,3,4-oxadiazole; xanthones; thiophene compounds; biphenylquinones such as 3,3',5,5'-tetra-tert-butylbiphenylquinone; benzophenones such as 4-hydroxybenzophenone and 2,3,4-trihydroxybenzophenone; and isoelectronic transport substances.

[0437] Especially as electron-accepting compounds, compounds having an anthraquinone structure are preferred, for example. As compounds having an anthraquinone structure, hydroxyanthraquinone compounds, aminoanthraquinone compounds, aminohydroxyanthraquinone compounds, etc. are preferred, specifically, anthraquinones, alizarin, quinone alizarin, anthraquinone, rutin, 4-ethoxy-1,2-hydroxy-9,10-anthraquinones and their derivatives are preferred.

[0438] Electron-accepting compounds can be dispersed in the undercoat along with inorganic particles, or they can be contained in the undercoat in a state of being attached to the surface of inorganic particles.

[0439] Methods for attaching electron-accepting compounds to the surface of inorganic particles include, for example, dry or wet methods.

[0440] A dry method, for example, involves directly adding an electron-accepting compound or an electron-accepting compound dissolved in an organic solvent while stirring inorganic particles using a mixer with high shear force, and then spraying it together with dry air or nitrogen, thereby causing the electron-accepting compound to adhere to the surface of the inorganic particles. When adding or spraying the electron-accepting compound, it is preferable to do so at a temperature below the boiling point of the solvent. After adding or spraying the electron-accepting compound, sintering can be performed at a temperature above 100°C. There are no particular limitations on the temperature and time of sintering, as long as the electron photographic properties are obtained.

[0441] Wet processes, for example, involve dispersing inorganic particles in a solvent using a mixer, ultrasonic disperser, sand mill, grinder, or ball mill. An electron-accepting compound is added, and the mixture is stirred or dispersed. The solvent is then removed, allowing the electron-accepting compound to adhere to the surface of the inorganic particles. Solvent removal methods include filtration or evaporation. After solvent removal, sintering can be performed at temperatures above 100°C. The temperature and time for sintering are not particularly limited as long as the electron imaging properties are obtained. In wet processes, the moisture content of the inorganic particles can be removed before adding the electron-accepting compound. Examples include removing moisture while stirring and heating in a solvent, or removing it through azeotropic mixing with the solvent.

[0442] The attachment of electron-receiving compounds can be performed before or after surface treatment of inorganic particles using a surface treatment agent, or the attachment of electron-receiving compounds can be performed simultaneously with surface treatment using a surface treatment agent.

[0443] The content of the electron-accepting compound relative to the inorganic particles is preferably 0.01% by mass or more and 20% by mass or less, more preferably 0.01% by mass or more and 10% by mass or less.

[0444] Examples of known polymeric compounds used as adhesive resins in the undercoat include acetal resins (such as polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, unsaturated polyester resins, methacrylic acid resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, urea resins, phenolic resins, phenolic-formaldehyde resins, melamine resins, urethane resins, alkyd resins, and epoxy resins; zirconium chelate compounds; titanium chelate compounds; aluminum chelate compounds; titanium alkoxide compounds; organotitanium compounds; and silane coupling agents.

[0445] Examples of adhesive resins used in the undercoat include charge-transporting resins with charge-transporting groups and conductive resins (e.g., polyaniline).

[0446] The adhesive resin used in the lower coating layer is preferably a resin that is insoluble in the coating solvent, and more preferably a resin obtained by reacting a curing agent with at least one resin selected from the group consisting of thermosetting resins such as urea resin, phenolic resin, phenolic-formaldehyde resin, melamine resin, urethane resin, unsaturated polyester resin, alkyd resin, and epoxy resin; polyamide resin, polyester resin, polyether resin, methacrylic resin, acrylic resin, polyvinyl alcohol resin, and polyvinyl alcohol acetal resin.

[0447] When using two or more adhesive resins in combination, the mixing ratio should be set as needed.

[0448] To improve electrical properties, environmental stability, and image quality, various additives can be included in the undercoat.

[0449] Examples of additives include polycyclic condensation pigments, azo pigments, zirconium chelates, titanium chelates, aluminum chelates, titanium alkoxides, organotitanium compounds, and silane coupling agents. As mentioned earlier, silane coupling agents are used for surface treatment of inorganic particles, but they can also be added as additives to undercoatings.

[0450] Examples of silane coupling agents used as additives include vinyltrimethoxysilane, 3-methacryloyloxypropyltris(2-methoxyethoxy)silane, 2-(3,4-epoxycyclohexyl)ethyltrimethoxysilane, 3-glycidoxypropyltrimethoxysilane, vinyltriacetoxysilane, 3-mercaptopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, N-2-(aminoethyl)-3-aminopropyltrimethoxysilane, N-2-(aminoethyl)-3-aminopropylmethyldimethoxysilane, N,N-bis(2-hydroxyethyl)-3-aminopropyltriethoxysilane, and 3-chloropropyltrimethoxysilane.

[0451] Examples of zirconium chelate compounds include zirconium butoxide, ethyl zirconium acetoacetate, zirconium triethanolamine, zirconium acetylacetone butoxide, zirconium acetoacetate butoxide, zirconium acetate, zirconium oxalate, zirconium lactate, zirconium phosphonate, zirconium octanoate, zirconium naphthenate, zirconium laurate, zirconium stearate, zirconium isostearate, zirconium methacrylate butoxide, zirconium stearate butoxide, and zirconium isostearate butoxide.

[0452] Examples of titanium chelate compounds include tetraisopropyl titanate, tetrabutyl titanate, tetrabutyl titanate dimer, tetra(2-ethylhexyl) titanate, titanium acetylacetone, polyacetylacetone titanium, octanediol titanium, titanium ammonium lactate, titanium lactate, titanium ethyl lactate, titanium triethanolamine, and titanium polyhydroxystearate.

[0453] Examples of aluminum chelate compounds include aluminum isopropoxide, aluminum monobutoxydiisopropoxide, aluminum butoxide, aluminum diacetoacetate diisopropoxide, and aluminum triacetoacetate.

[0454] These additives can be used alone or as a mixture or condensation polymer of multiple compounds.

[0455] The undercoat is preferably coated with a Vickers hardness of 35 or higher.

[0456] To suppress interference ripples, the surface roughness (ten-point average roughness) of the lower coating is preferably adjusted to, for example, 1 / (4n) to 1 / 2 of the wavelength λ of the laser used for exposure (where n is the refractive index of the upper layer).

[0457] To adjust surface roughness, resin particles can be added to the undercoat. Examples of resin particles include silicone resin particles and cross-linked polymethyl methacrylate resin particles. Furthermore, to adjust surface roughness, the surface of the undercoat can be ground. Examples of grinding methods include polishing, sandblasting, wet grinding, and grinding.

[0458] There are no particular limitations on the formation of the undercoat, and known formation methods can be used. However, for example, the formation of the undercoat is carried out by adding the above-mentioned components to the solvent to form a coating film of the coating liquid, drying the coating film, and heating as needed.

[0459] As solvents used to prepare coating liquids for forming the undercoat, known organic solvents can be cited, such as alcohol solvents, aromatic hydrocarbon solvents, halogenated hydrocarbon solvents, ketone solvents, ketol solvents, ether solvents, ester solvents, etc.

[0460] Specifically, examples of these solvents include, for instance, methanol, ethanol, n-propanol, isopropanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, ethyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, dichloromethane, chloroform, chlorobenzene, toluene, and other common organic solvents.

[0461] Methods for dispersing inorganic particles during the preparation of coating liquid for forming a lower coating include, for example, known methods such as roller mills, ball mills, vibratory ball mills, grinding mills, sand mills, colloid mills, and paint mixers.

[0462] Methods for applying a coating liquid for forming an undercoat onto a conductive substrate include, for example, scraper coating, wire rod coating, spraying, dip coating, bead coating, air knife coating, and curtain coating.

[0463] The thickness of the lower coating is preferably 15 μm or more, and more preferably set in the range of 20 μm or more and 50 μm or less.

[0464] <Intermediate Layer>

[0465] The intermediate layer may be, for example, a layer containing resin. Examples of resins used in the intermediate layer include acetal resins (such as polyvinyl butyral), polyvinyl alcohol resins, polyvinyl acetal resins, casein resins, polyamide resins, cellulose resins, gelatin, polyurethane resins, polyester resins, methacrylic acid resins, acrylic resins, polyvinyl chloride resins, polyvinyl acetate resins, vinyl chloride-vinyl acetate-maleic anhydride resins, silicone resins, silicone-alkyd resins, phenolic-formaldehyde resins, melamine resins, and other polymeric compounds.

[0466] The intermediate layer can be a layer containing an organometallic compound. Examples of organometallic compounds used as intermediate layers include those containing metal atoms such as zirconium, titanium, aluminum, manganese, and silicon.

[0467] The compounds used in these intermediate layers can be used alone or as a mixture of multiple compounds or as condensation polymers.

[0468] The intermediate layer is preferably a layer containing an organometallic compound containing zirconium or silicon atoms.

[0469] There are no particular limitations on the formation of the intermediate layer, and known formation methods can be used. However, for example, the intermediate layer is formed by adding the above-mentioned components to the solvent to form a coating film of the coating liquid, drying the coating film, and heating as needed.

[0470] As a coating method for forming the intermediate layer, conventional methods such as dip coating, push coating, bar coating, spraying, scraper coating, air knife coating, and curtain coating can be used.

[0471] The thickness of the intermediate layer is preferably set in the range of 0.1 μm or more and 3 μm or less. The intermediate layer can be used as the lower coating layer.

[0472] <charge generation layer>

[0473] The charge generation layer is, for example, a layer comprising a charge generation material and a binding resin. Furthermore, the charge generation layer can be a vapor-deposited layer of the charge generation material. Vapor-deposited layers of charge generation material are suitable, for example, for use with incoherent light sources such as LED (Light Emitting Diode) and organic EL (Electro-Luminescence) image arrays.

[0474] Examples of charge-generating materials include azo pigments such as diazo and triazo; fused-ring aromatic pigments such as dibromoanthracene anthrone; perylene pigments; pyrrolopyrrole pigments; phthalocyanine pigments; zinc oxide; and trigonal selenium.

[0475] To cope with laser exposure in the near-infrared region, metal phthalocyanine pigments or metal-free phthalocyanine pigments are preferably used as charge-generating materials. Specifically, hydroxy gallium phthalocyanine, gallium chloride phthalocyanine, dichlorotin phthalocyanine, and titanium dioxide phthalocyanine are more preferred.

[0476] On the other hand, in order to cope with laser exposure in the near-ultraviolet region, the preferred charge-generating materials are, for example, fused-ring aromatic pigments such as dibromoanthracene; sulfur-indigo pigments; porphyrin compounds; zinc oxide; trigonal selenium; and diazo pigments.

[0477] The above-mentioned charge-generating materials can be used even when using incoherent light sources such as LEDs and organic EL image arrays with a center wavelength of light emission above 450nm and below 780nm.

[0478] When n-type semiconductors such as fused-ring aromatic pigments, perylene pigments, and azo pigments are used as charge-generating materials, dark currents are less likely to be generated, and even when used as thin films, image defects known as black spots can be suppressed. The determination of n-type is based on the commonly used time-of-flight method and the polarity of the flowing photocurrent; semiconductors that flow more easily than holes, using electrons as charge carriers, are classified as n-type.

[0479] The adhesive resin used in the charge generation layer is selected from a wide range of insulating resins, and the adhesive resin can be selected from organic photoconductive polymers such as poly-N-vinylcarbazole, polyvinyl anthracene, polyvinylpyrene, and polysilane.

[0480] Examples of adhesive resins include polyvinyl butyral resin, polyarylate resins (condensates of bisphenols and aromatic dicarboxylic acids, etc.), polycarbonate resin, polyester resin, phenoxy resin, vinyl chloride-vinyl acetate copolymer, polyamide resin, acrylic resin, polyacrylamide resin, polyvinylpyridine resin, cellulose resin, urethane resin, epoxy resin, casein, polyvinyl alcohol resin, and polyvinylpyrrolidone resin. Here, "insulation" refers to a volume resistivity of 1×10⁻⁶. 13 Ω·cm or higher. These adhesive resins can be used alone or in combination of two or more.

[0481] The ratio of the charge-generating material to the binder resin is preferably in the range of 10:1 to 1:10 by mass.

[0482] Other known additives may be included in the charge generation layer.

[0483] There are no particular limitations on the formation of the charge-generating layer, and known formation methods can be used. However, for example, it can be performed by forming a coating film of a charge-generating layer forming liquid by adding the above-mentioned components to a solvent, drying the coating film, and heating it as needed. The formation of the charge-generating layer can be performed by vapor deposition of a charge-generating material. The formation of the charge-generating layer based on vapor deposition is particularly suitable, for example, when using polycyclic aromatic pigments or perylene pigments as charge-generating materials.

[0484] Examples of solvents used in preparing coating solutions for forming charge-generating layers include methanol, ethanol, n-propanol, n-butanol, benzyl alcohol, methyl cellosolve, ethyl cellosolve, acetone, methyl ethyl ketone, cyclohexanone, methyl acetate, n-butyl acetate, dioxane, tetrahydrofuran, dichloromethane, chloroform, chlorobenzene, and toluene. These solvents can be used alone or in combination of two or more.

[0485] As a method for dispersing particles (e.g., charge-generating materials) in a coating liquid for forming a charge-generating layer, media dispersers such as ball mills, vibratory ball mills, grinders, sand mills, and horizontal sand mills, or media-free dispersers such as mixers, ultrasonic dispersers, roller mills, and high-pressure homogenizers can be used. Examples of high-pressure homogenizers include collision methods that disperse the dispersion by liquid-liquid collisions or liquid-wall collisions under high pressure, and penetration methods that disperse the dispersion by penetrating fine flow paths under high pressure. During dispersion, it is effective to set the average particle size of the charge-generating material in the coating liquid for forming the charge-generating layer to 0.5 μm or less, preferably 0.3 μm or less, and more preferably 0.15 μm or less.

[0486] Methods for applying a coating liquid for forming a charge generation layer onto an underlying layer (or an intermediate layer) include, for example, scraper coating, wire rod coating, spraying, dip coating, bead coating, air knife coating, curtain coating, and other common methods.

[0487] The thickness of the charge generation layer is preferably set in the range of 0.1 μm or more and 5.0 μm or less, and more preferably in the range of 0.2 μm or more and 2.0 μm or less.

[0488] <charge transport layer>

[0489] The charge transport layer may be, for example, a layer comprising a binding resin and a charge transport material. Alternatively, the charge transport layer may be a layer comprising a polymeric charge transport material.

[0490] Examples of charge transport materials include quinone compounds such as p-benzoquinone, chloroquinone, tetrabromobenzoquinone, and anthraquinone; dimethyl compounds such as tetracyano-p-benzodiquinone; fluorenone compounds such as 2,4,7-trinitrofluorenone; anthrone compounds; benzophenone compounds; cyanoethylene compounds; and ethylene compounds, all of which are electron transport compounds. Examples of hole transport materials include triarylamine compounds, benzidine compounds, arylalkyl compounds, aryl-substituted ethylene compounds, piracene compounds, anthracene compounds, and hydrazone compounds, all of which are hole transport compounds. These charge transport materials can be used alone or in combination, but are not limited to this.

[0491] From the viewpoint of charge mobility, the preferred charge transport materials are, for example, triarylamine derivatives represented by the following structural formula (a-1) and benzidine derivatives represented by the following structural formula (a-2).

[0492] [Chemical Formula 37]

[0493]

[0494] In structural formula (a-1), Ar T1 Ar T2 and Ar T3 Each independently represents a substituted or unsubstituted aryl group, -C6H4-C(R) T4 )=C(R T5 (R) T6 ) or -C6H4-CH=CH-CH=C(R T7 (R) T8 R T4 R T5 R T6 R T7 and R T8 Each of the following can be independently represented: a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group.

[0495] Examples of substituents for the aforementioned groups include halogen atoms, alkyl groups having 1 or more but 5 or fewer carbon atoms, and alkoxy groups having 1 or more but 5 or fewer carbon atoms. Furthermore, examples of substituents for the aforementioned groups include substituted amino groups substituted with alkyl groups having 1 or more but 3 or fewer carbon atoms.

[0496] [Chemical Formula 38]

[0497]

[0498] In structural formula (a-2), R T91 and R T92 Each of the following can be independently represented: a hydrogen atom, a halogen atom, an alkyl group having 1 or more but less than 5 carbon atoms, or an alkoxy group having 1 or more but less than 5 carbon atoms. RT101 R T102 R T111 and R T112 Each of the following can be independently represented: a halogen atom, an alkyl group having 1 or more but less than 5 carbon atoms, an alkoxy group having 1 or more but less than 5 carbon atoms, an amino group substituted with an alkyl group having 1 or more but less than 2 carbon atoms, a substituted or unsubstituted aryl group, or a -C(R) group. T12 )=C(R T13 (R) T14 ) or -CH=CH-CH=C(R T15 (R) T16 ), R T12 R T13 R T14 R T15 and R T16 Each of these independently represents a hydrogen atom, a substituted or unsubstituted alkyl group, or a substituted or unsubstituted aryl group. Tm1, Tm2, ​​Tn1, and Tn2 each independently represent an integer greater than 0 and less than 2.

[0499] Examples of substituents for the aforementioned groups include halogen atoms, alkyl groups having 1 or more but 5 or fewer carbon atoms, and alkoxy groups having 1 or more but 5 or fewer carbon atoms. Furthermore, examples of substituents for the aforementioned groups include substituted amino groups substituted with alkyl groups having 1 or more but 3 or fewer carbon atoms.

[0500] From the viewpoint of charge mobility, among the triarylamine derivatives represented by structural formula (a-1) and the benzidine derivatives represented by structural formula (a-2), those having "-C6H4-CH=CH-CH=C(R)" are particularly preferred, for example. T7 (R) T8 Triarylamine derivatives with "-CH=CH-CH=C(R)" and those with "-CH=CH-CH=C(R)" T15 (R) T16 )" benzidine derivatives.

[0501] Examples of polymeric charge transport materials include poly-N-vinylcarbazole, polysilane, and other known materials with charge transport properties. Polyester-based polymeric charge transport materials are particularly preferred. These materials can be used alone or in combination with binder resins.

[0502] Examples of binder resins used in the charge transport layer include polycarbonate resins, polyester resins, polyarylate resins, methacrylic resins, acrylic resins, polyvinyl chloride resins, polyvinylidene chloride resins, polystyrene resins, polyvinyl acetate resins, styrene-butadiene copolymers, vinylidene chloride-acrylonitrile copolymers, vinyl chloride-vinyl acetate copolymers, vinyl chloride-vinyl acetate-maleic anhydride copolymers, silicone resins, silicone alkyd resins, phenol-formaldehyde resins, styrene-alkyd resins, poly-N-vinylcarbazole, and polysilanes. Among these, polycarbonate resins or polyarylate resins are preferred as binder resins. These binder resins may be used alone or in combination with two or more other resins.

[0503] The mass ratio of charge transport material to binder resin is preferably, for example, 10:1 to 1:5.

[0504] When the charge transport layer is the outermost layer of the photoreceptor, the charge transport layer comprises at least two resins. In this case, the charge transport layer preferably contains at least one of a polyaryl ester resin and a polycarbonate resin, and more preferably contains both a polyaryl ester resin and a polycarbonate resin. As a combination of the polyaryl ester resin and the polycarbonate resin, a combination of resins in which both have a biphenyl structural unit represented by the inclusion formula (BP) is preferred. As a polyaryl ester resin, a polyaryl ester resin (PA) is preferred, for example.

[0505] In the case where the charge transport layer is the outermost layer of the photoreceptor, the charge transport layer contains phenolic compounds. The morphology of the phenolic compounds is as described above.

[0506] Other known additives may be included in the charge transport layer.

[0507] There are no particular limitations on the formation of the charge transport layer, and known formation methods can be used. For example, a coating film can be formed by adding the above-mentioned components to a solvent for forming a charge transport layer, and the coating film can be dried and heated as needed.

[0508] Examples of solvents used in preparing coating solutions for charge transport layer formation include aromatic hydrocarbons such as benzene, toluene, xylene, and chlorobenzene; ketones such as acetone and 2-butanone; halogenated aliphatic hydrocarbons such as dichloromethane, chloroform, and vinyl chloride; and cyclic or linear ethers such as tetrahydrofuran and diethyl ether. These solvents can be used alone or in combination of two or more.

[0509] Common methods for applying a coating liquid for forming a charge transport layer onto a charge generation layer include scraper coating, wire rod coating, spraying, dip coating, bead coating, air knife coating, and curtain coating.

[0510] The thickness of the charge transport layer is preferably set in the range of 5 μm or more and 50 μm or less, more preferably in the range of 8 μm or more and 45 μm or less, and even more preferably in the range of 10 μm or more and 40 μm or less.

[0511] <Single-layer photosensitive layer>

[0512] A single-layer photosensitive layer (charge-generating / charge-transfer layer) is, for example, a layer comprising a charge-generating material, a charge-transfer material, and, if necessary, a binding resin and other known additives. These materials are the same as those described in the charge-generating layer and the charge-transfer layer.

[0513] In a single-layer photosensitive layer, the content of charge-generating material relative to the total solid content is preferably 0.1% by mass or more and 10% by mass or less, more preferably 0.8% by mass or more and 5% by mass or less. Furthermore, in a single-layer photosensitive layer, the content of charge-transporting material relative to the total solid content is preferably 5% by mass or more and 50% by mass or less.

[0514] The method for forming a single-layer photosensitive layer is the same as the method for forming a charge generation layer or a charge transport layer.

[0515] The thickness of the single-layer photosensitive layer is preferably 5 μm or more and 50 μm or less, more preferably 8 μm or more and 45 μm or less, and even more preferably 10 μm or more and 40 μm or less.

[0516] When a monolayer photosensitive layer is the outermost layer of a photoreceptor, the monolayer photosensitive layer comprises at least two resins. In this case, the monolayer photosensitive layer preferably contains at least one of a polyaryl ester resin and a polycarbonate resin, and more preferably contains both a polyaryl ester resin and a polycarbonate resin. As a combination of polyaryl ester resin and polycarbonate resin, a combination of resins in which both have a biphenyl structural unit represented by the inclusion formula (BP) is preferred. As a polyaryl ester resin, a polyaryl ester resin (PA) is preferred, for example.

[0517] When the monolayer photosensitive layer is the outermost layer of the photoreceptor, the monolayer photosensitive layer contains phenolic compounds. The morphology of the phenolic compounds is as described above.

[0518] The image forming apparatus according to this embodiment is applicable to the following known image forming apparatuses: an apparatus having a fixing apparatus for fixing a toner image transferred to the surface of a recording medium; an apparatus for a direct transfer method that directly transfers a toner image formed on the surface of an electrophotographic photosensitive body to the recording medium; an apparatus for an intermediate transfer method that transfers a toner image formed on the surface of an electrophotographic photosensitive body to the surface of an intermediate transfer body in one step, and then transfers the toner image transferred to the surface of the intermediate transfer body to the surface of the recording medium in a second step; an apparatus having an antistatic apparatus for irradiating the surface of an electrophotographic photosensitive body with antistatic light after the toner image is transferred but before it is charged to eliminate static electricity; and an apparatus having an electrophotographic photosensitive body heating member for raising the temperature of the electrophotographic photosensitive body and lowering the relative temperature, etc.

[0519] In the case of an intermediate transfer method apparatus, the transfer apparatus may have a structure that includes an intermediate transfer body for transferring a toner image onto a surface, a primary transfer apparatus for transferring a toner image formed on the surface of an electrophotographic photosensitive body to the surface of the intermediate transfer body in one step, and a secondary transfer apparatus for transferring the toner image transferred to the surface of the intermediate transfer body to the surface of a recording medium in a second step.

[0520] The image forming apparatus described in this embodiment can be either a dry developing image forming apparatus or a wet developing image forming apparatus (a developing method that utilizes liquid developer).

[0521] In the image forming apparatus according to this embodiment, for example, the portion including the electrophotographic photosensitive element can be a cassette structure (processing cassette) that is detachable from the image forming apparatus. As the processing cassette, for example, a processing cassette including the electrophotographic photosensitive element according to this embodiment is preferably used. In addition to the electrophotographic photosensitive element, the processing cassette may also include at least one selected from the group consisting of a charging device, an electrostatic latent image forming apparatus, a developing apparatus, and a transfer apparatus.

[0522] The following describes an example of the image forming apparatus according to this embodiment, but it is not limited thereto. The main parts shown in the figures will be described, while the description of other parts will be omitted.

[0523] Figure 7 This is a schematic structural diagram illustrating an example of the image forming apparatus according to this embodiment.

[0524] like Figure 7As shown, the image forming apparatus 100 according to this embodiment includes a processing cartridge 300 having an electrophotographic photosensitive element 7, an exposure apparatus 9 (an example of an electrostatic latent image forming apparatus), a transfer apparatus 40 (a primary transfer apparatus), and an intermediate transfer body 50. In the image forming apparatus 100, the exposure apparatus 9 is positioned to expose the electrophotographic photosensitive element 7 through the opening of the processing cartridge 300, and the transfer apparatus 40 is positioned opposite the electrophotographic photosensitive element 7 across the intermediate transfer body 50, with a portion of the intermediate transfer body 50 in contact with the electrophotographic photosensitive element 7. Although not shown, a secondary transfer apparatus is also included to transfer the toner image transferred to the intermediate transfer body 50 to a recording medium (e.g., paper). The intermediate transfer body 50, the transfer apparatus 40 (a primary transfer apparatus), and the secondary transfer apparatus (not shown) are examples of transfer apparatuses.

[0525] Figure 7 The processing cartridge 300 integrally supports the electrophotographic photoreceptor 7, the charging device 8 (an example of the charging device), the developing device 11 (an example of the developing device), and the cleaning device 13 (an example of the cleaning device) within the housing. The cleaning device 13 has a cleaning blade (an example of a cleaning component) 131, which is configured to contact the surface of the electrophotographic photoreceptor 7. The cleaning component may be a conductive or insulating fibrous component instead of the cleaning blade 131, and may be used alone or in conjunction with the cleaning blade 131.

[0526] exist Figure 7 In the example shown, as an image forming apparatus, a fibrous component 132 (roller-shaped) is provided for supplying lubricant 14 to the surface of the electrophotographic photosensitive element 7, and a fibrous component 133 (flat brush-shaped) is provided for auxiliary cleaning, but they can be configured as needed.

[0527] The structure of the image forming apparatus according to this embodiment will be described below.

[0528] -Electrified devices-

[0529] The energized device 8 uses the aforementioned energized device.

[0530] -Exposure device-

[0531] Examples of exposure devices 9 include optical systems that expose semiconductor lasers, LED lights, liquid crystal shutter lights, etc., onto the surface of an electrophotographic photosensitive object 7 to form a predetermined pattern. The wavelength of the light source is set within the spectral sensitivity range of the electrophotographic photosensitive object. Near-infrared light with an oscillation wavelength around 780 nm is the most common wavelength for semiconductor lasers. However, it is not limited to this wavelength; lasers with an oscillation wavelength in the 600 nm band or blue lasers, or lasers with an oscillation wavelength in the range of 400 nm to 450 nm, can be used. Furthermore, surface-emitting laser sources capable of outputting multiple beams for forming color images are also effective.

[0532] -Developing apparatus-

[0533] As a developing apparatus 11, examples include conventional developing apparatuses that perform development by contact or non-contact with the developer. There are no particular limitations on the developing apparatus 11 as long as it possesses the aforementioned functions, and it can be selected according to the purpose. For example, known developing machines that use brushes, rollers, etc., to adhere single-component or two-component developers to the electrophotographic photosensitive element 7 can be cited. Among these, a developing machine that uses a developing roller to hold the developer on the surface is preferred, for example.

[0534] The developer used in the developing apparatus 11 can be a single-component developer containing only a toner, or a two-component developer containing both a toner and charge carriers. Furthermore, the developer can be magnetic or non-magnetic. Commonly known developers are acceptable.

[0535] -Cleaning Device-

[0536] The cleaning device 13 is a cleaning scraper device equipped with a cleaning scraper 131. In addition to the cleaning scraper method, a brush cleaning method or a simultaneous developing and cleaning method can also be used.

[0537] -Transfer Device-

[0538] As a transfer device 40, examples include contact transfer belt appliances that use belts, rollers, films, rubber squeegees, etc.; grid corona tube transfer belt appliances that utilize corona discharge; and corona tube transfer belt appliances, which are known in themselves.

[0539] -Intermediate Transfer Material-

[0540] As the intermediate transfer body 50, a strip-shaped transfer body (intermediate transfer tape) containing polyimide, polyamide-imide, polycarbonate, polyarylate, polyester, rubber, etc., which are endowed with semi-conductivity is used. Furthermore, in addition to the strip shape, a drum-shaped transfer body can also be used as the intermediate transfer body.

[0541] Figure 8This is a schematic structural diagram showing another example of the image forming apparatus according to this embodiment.

[0542] Figure 8 The image forming apparatus 120 shown is a multicolor image forming apparatus equipped with four processing cartridges 300 arranged in series. In the image forming apparatus 120, four processing cartridges 300 are arranged side by side on the intermediate transfer body 50, and a structure is formed in which one electrophotographic photosensitive element is used for each color. Except for the series arrangement, the image forming apparatus 120 has the same structure as the image forming apparatus 100.

[0543] Example

[0544] The following describes the implementation of the invention in detail with reference to the embodiments, but the implementation of the invention is not limited to these embodiments in any way.

[0545] Unless otherwise specified, “parts” and “%” are quality standards in the following description.

[0546] Unless otherwise specified, the synthesis, processing, and manufacturing processes are carried out at room temperature (25℃±3℃).

[0547] <Synthesis of Polyarylate Resins>

[0548] Polyaryl ester resins (1-1) to (1-6) were prepared. The units and composition constituting the polyaryl ester resins are shown in Table 1.

[0549] Table 1 records "Structural Unit: Composition Ratio" (e.g., A2-3:50). The composition ratio is the mol% of each dicarboxylic acid unit and diol unit.

[0550] The A2-3 examples listed in Table 1 are specific examples of the dicarboxylic acid units (A) that have been described.

[0551] The B1-4 listed in Table 1 are specific examples of the diol units (B) that have been described.

[0552] (Example 1)

[0553] <Manufacturing of a photoreceptor with stacked photosensitive layers>

[0554] -Formation of the undercoat-

[0555] An aluminum cylindrical tube was prepared as the conductive substrate.

[0556] 3.5 parts of butyral resin (trade name: S-LEC BM-1, SEKISUI CHEMICAL CO.,LTD.) and 41 parts of methyl ethyl ketone were mixed and dissolved. 10 parts of curing agent (blocked isocyanate, trade name: SUMIDUR 3175, Sumitomo Bayer Urethane Co.,Ltd.), 45.5 parts of zinc oxide (trade name: SMZ-017N, TAYCA CORPORATION) surface-treated with silane coupling agent (trade name: KBM603, Shin-Etsu Chemical Co.,Ltd.), and 0.27 parts of 4-ethoxy-1,2-hydroxy-9,10-anthraquinone) were added, and the mixture was stirred. The mixture was then dispersed using 1 mm diameter glass beads in a sand mill for 2 hours. Furthermore, 0.01 parts of dioctyltin dilaurate and 2 parts of silicone resin particles (trade name: TOSPEARL145, GE Toshiba Silicones Co., Ltd.) were added and stirred to obtain a coating solution for forming the lower coating layer. The coating solution for forming the lower coating layer was applied to the outer peripheral surface of the conductive substrate by dip coating method, and dried and cured at 170°C for 40 minutes to form a lower coating layer with a thickness of 20 μm.

[0557] -Formation of the charge generation layer-

[0558] A mixture consisting of 15 parts of gallium hydroxyphthalocyanine (which exhibits diffraction peaks at Bragg angles (2θ±0.2°) of at least 7.5°, 9.9°, 12.5°, 16.3°, 18.6°, 25.1°, and 28.3° in X-ray diffraction spectra using Cukα characteristic X-rays), 10 parts of vinyl chloride-vinyl acetate copolymer resin (trade name: VMCH, manufactured by Nippon Unicar Company Limited), and 200 parts of n-butyl acetate was dispersed using glass beads with a diameter of 1 mm and a sand mixer for 4 hours. 175 parts of n-butyl acetate and 180 parts of methyl ethyl ketone were added to the dispersion, and the mixture was stirred to obtain a coating solution for forming a charge-generating layer. The coating solution for forming the charge-generating layer was impregnated onto a lower coating layer and dried at room temperature (25°C±3°C) to form a charge-generating layer with an average thickness of 0.18 μm.

[0559] -Formation of the charge transport layer-

[0560] 42 parts of polyarylate resin (1-1) as the binder resin, 18 parts of polycarbonate resin PC-1, and 40 parts of CTM-1 as the charge transport material were dissolved in 270 parts of tetrahydrofuran and 30 parts of toluene to obtain a coating solution for forming a charge transport layer. The coating solution was applied to the charge generation layer and dried at 145°C for 30 minutes to form a charge transport layer. The average thickness As of the charge transport layer is shown in Table 1.

[0561] In addition, polycarbonate resin PC-1 is a resin composed of the following repeating structural units. The numbers marked on the structural units indicate the molar ratio.

[0562] [Chemical Formula 39]

[0563]

[0564] [Chemical Formula 40]

[0565]

[0566] -Making of Cleaning Rollers-

[0567] A 2.5mm thick sheet of polyurethane foam (EP-70; manufactured by Inoac Corporation) is cut into strips 3.0mm wide. A 0.05mm thick double-sided adhesive tape (manufactured by NITTO DENKOCORPORATION, No. 5605) is then applied to the entire surface of the cut strips to obtain strips with double-sided tape.

[0568] The obtained strip with double-sided tape is placed on a horizontal table with the release liner of the double-sided tape facing downwards. Then, the front end of the strip is compressed from the top using heated stainless steel so that the thickness of a 1mm section along the long side from the front end is 15% of the thickness of the other parts.

[0569] The three strips with double-sided tape attached are placed on a horizontal table with the release paper attached to the tape facing upwards. Tension is applied while winding them onto a metal mandrel (material: SUM24EZ, outer diameter: ) at a helical angle θ of 25° and extending within the range of 0% to 5% of the total length of the strips. ).

[0570] Through the above processes, a cleaning roller with a foamed elastic layer is obtained by spirally winding the mandrel on its outer circumference.

[0571] <Making of Electric Rollers>

[0572] -Formation of the elastic layer-

[0573] The following mixture was kneaded using an open roll and then coated onto the outer circumference of a 9mm diameter conductive core made of SUS416 in a cylindrical shape, resulting in a thickness of 1.5mm. The core was then placed in a cylindrical mold with an inner diameter of 12.0mm and vulcanized at 170°C for 30 minutes. After being removed from the mold, it was ground. This yielded a cylindrical conductive elastic layer.

[0574] • Rubber material (epoxychloropropane-ethylene oxide-allyl glycidyl ether copolymer rubber, GECHRON 3106, manufactured by Zeon Corporation): 100 parts by weight

[0575] • Conductive agent (carbon black, manufactured by Asahi Thermal, ASAHI CARBON CO.,LTD): 25 parts by weight

[0576] • Conductive agent (Ketjenblack EC, manufactured by Lion Corporation): 8 parts by weight

[0577] • Ionic conductive agent (lithium perchlorate): 1 part by weight

[0578] • Vulcanizing agent (sulfur, 200 mesh, manufactured by Tsurumi Chemical Industry Co., Ltd.): 1 part by weight

[0579] • Vulcanization accelerator (NOCCELER DM, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO.,LTD.): 2.0 parts by weight

[0580] • Vulcanization accelerator (NOCCELER TT, manufactured by OUCHI SHINKO CHEMICAL INDUSTRIAL CO.,LTD.): 0.5 parts by weight

[0581] -Formation of the surface layer-

[0582] The following mixture was dispersed using a bead mill, the resulting dispersion was diluted with methanol, and then impregnated onto the surface (outer peripheral surface) of a conductive elastic layer. The mixture was then heated and dried at 140°C for 15 minutes. This yielded a charged roller with a surface layer of 4 μm thickness.

[0583] • Polymer materials (copolymer nylon, Amilan CM8000, manufactured by TORAY INDUSTRIES, INC.): 100 parts by weight

[0584] • Conductive agent (antimony-doped tin oxide, SN-100P, manufactured by Ishihara Sanyo Kaisha, Ltd.): 30 parts by weight

[0585] Solvent (methanol): 500 parts by weight

[0586] • Solvent (butanol): 240 parts by weight

[0587] <Evaluation of the abrasion resistance of photoreceptors>

[0588] The obtained electrophotographic photosensitive material, charged roller, and cleaning roller were installed on the image forming apparatus “ApeosPort-VC7776 manufactured by FUJIFILM Business Innovation Co., Ltd.”

[0589] Using the image forming apparatus, 100,000 images with an average density (area coverage) of 10% were formed on A3-sized paper at an environment of 28°C and 85% relative humidity. Another 100,000 images were then formed at 10°C and 15% relative humidity. The average thickness of the outermost layer before image formation (TBEFORE) (μm) and the average thickness of the outermost layer after image formation (TAFTER) (μm) were calculated, and their difference ΔT (=TBEFORE-TAFTER) was taken as the wear amount. A PERMASCOPE manufactured by Fisher Instruments KK was used as the film thickness measuring instrument. Furthermore, the contact line pressure of the cleaning blade in the image forming apparatus relative to the surface of the electrophotographic photoreceptor was set to 2.6 gf / mm, and the contact angle was set to 11 degrees. The wear amount was evaluated according to the following criteria. S~C represents the allowable range. The results are shown in Table 1.

[0590] -Evaluation Criteria-

[0591] S: Wear amount less than 15μm

[0592] A: Wear amount is greater than 15μm and less than 20μm

[0593] B: Wear amount is greater than 20μm and less than 25μm

[0594] C: Wear amount is greater than 25μm and less than 30μm

[0595] D: Wear amount is above 30μm

[0596] <Evaluation of the contamination resistance of live components>

[0597] In the evaluation test, 100,000 strip-shaped images with a length of 320 mm and a width of 30 mm in the output direction were printed on A3 recording paper at 100% image density under an environment of 28°C and 85% RH. Another 100,000 strips were then printed under the same conditions at 10°C and 15% relative humidity. The cleanliness of the deposits was evaluated by observing the surface condition at the printed image location on the electrified roller 14. The surface of the electrified roller was directly observed using a confocal laser microscope (OLS1100, manufactured by Olympus Corporation), and the contamination resistance of the electrified components was evaluated based on the following criteria.

[0598] -Evaluation Criteria-

[0599] S: The amount of deposits on the surface of the charged roller is less than 1 μm. 2 It was observed in the range of less than 10%.

[0600] A: The deposits on the surface of the charged roller are present at a density of 1μm. 2 It was observed in the range of greater than 10% and less than 20%.

[0601] B: The amount of residue adhering to the surface of the electrified roller is per 1μm 2 It was observed in the range of greater than 20% and less than 30%.

[0602] C: The amount of deposits on the surface of the charged roller is less than 1 μm. 2 It was observed in the range of greater than 30% and less than 50%.

[0603] D: The amount of deposits on the surface of the charged roller is less than 1 μm. 2 It was observed in the range of more than 50%.

[0604] (Examples 2 to 29 and Comparative Examples 1 to 6)

[0605] As described in Table 1, the composition of the charge transport layer, the shape of the cleaning component, and the surface roughness Rz of the charged component were changed. Otherwise, the electrophotographic photosensitive body, the charged roller, and the cleaning roller were manufactured in the same manner as in Example 1.

[0606] Furthermore, the evaluation was conducted in the same manner as in Example 1. The evaluation results are shown in Table 1.

[0607] [Table 1]

[0608]

[0609] Additionally, the resin mass ratio PAR:PC in Table 1 represents the ratio of polyarylate resin to polycarbonate resin. Furthermore, the polycarbonate resin used in Example 29 is polycarbonate resin PC-3 with the following structure.

[0610] [Chemical Formula 41]

[0611]

[0612] Regarding the CTMs used in Examples 27 and 28, CTM-1 and CTM-2 were used simultaneously at a mass ratio of 30:70.

[0613] [Chemical Formula 42]

[0614]

[0615] (Examples 30 to 34 and Comparative Examples 7 to 8)

[0616] Furthermore, the shape of the cleaning components was changed in Examples 30 to 34 and Comparative Examples 7 to 8 as described in Table 2. Apart from this, the cleaning roller was manufactured in the same manner as in Example 1, and each component was modified into a drum and mounted on the image forming apparatus “bizhub C287 manufactured by Konica Minolta, Inc.”. The abrasion resistance of the photoreceptor and the contamination resistance of the charged components were evaluated in the same manner as in Example 1.

[0617] The evaluation results are shown in Table 2.

[0618] [Table 2]

[0619]

[0620] As shown in Tables 1 and 2, the image forming apparatuses of Examples 1 to 34 exhibit superior resistance to wear of the photoreceptor and resistance to contamination of charged components compared to the image forming apparatuses of Comparative Examples 1 to 8.

[0621] (1) An image forming apparatus comprising: an electrophotographic photosensitive element and a charging device having a charging member for charging the surface of the electrophotographic photosensitive element and a cleaning member disposed in contact with the charging member, the electrophotographic photosensitive element having a conductive substrate and a photosensitive layer disposed on the conductive substrate, and the outermost surface layer of the electrophotographic photosensitive element comprising a charge transport material and a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B), the cleaning member having a core rod and a foamed elastic layer disposed in a spiral shape on the outer peripheral surface of the core rod, the ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer being 0.6 or more and 1.2 or less.

[0622] [Chemical Formula 43]

[0623] Formula (A)

[0624] Formula (B)

[0625] In equation (A), Ar A1 and Ar A2 Each is an aromatic ring that can have substituents, L A It is a single bond or a divalent linker, n A1 It can be 0, 1, or 2.

[0626] In equation (B), Ar B1 and Ar B2 Each is an aromatic ring that can have substituents, L B It is a single bond, an oxygen atom, a sulfur atom, or -C(Rb) 1 (Rb) 2 )-,n B1 It can be 0, 1, or 2. Rb 1 and Rb 2 Rb is independently composed of hydrogen atoms, an alkyl group having 1 or more but less than 20 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 1 With Rb 2 They can bond together to form cyclic alkyl groups.

[0627] (2) The image forming apparatus according to (1), wherein the coverage area ratio A of the foamed elastic layer disposed on the cleaning member is 20% or more and 60% or less.

[0628] (3) The image forming apparatus according to (1) or (2), wherein the surface roughness Rz of the charged component is 5 μm or more and 10 μm or less.

[0629] (4) The image forming apparatus according to any one of (1) to (3), wherein the outermost layer of the electrophotographic photoreceptor further comprises a polycarbonate resin.

[0630] (5) The image forming apparatus according to (4), wherein the mass ratio of the polyarylate resin to the polycarbonate resin in the outermost layer of the electrophotographic photoreceptor is 3:7 to 7:3.

[0631] (6) The image forming apparatus according to any one of (1) to (5), wherein the dicarboxylic acid unit represented by formula (A) comprises at least one selected from the group consisting of dicarboxylic acid unit (A1) represented by formula (A2), dicarboxylic acid unit (A3) represented by formula (A4), and dicarboxylic acid unit (A5) represented by formula (A5).

[0632] [Chemical Formula 44]

[0633] Equation (A1)

[0634] Formula (A2)

[0635] Formula (A3)

[0636] Equation (A4)

[0637] Formula (A5)

[0638] In equation (A1), n 101 n is an integer greater than 0 and less than 4. 101 Ra 101 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0639] In equation (A2), n 201 and n 202 Each of the following is an independent integer greater than 0 and less than 4, n 201 Ra 201 and n 202 Ra 202 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0640] In equation (A3), n 301 and n 302 Each of the following is an independent integer greater than 0 and less than 4, n 301 Ra 301 and n 302 Ra 302 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0641] In equation (A4), n 401 n is an integer greater than 0 and less than 6. 401 Ra 401 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0642] In equation (A5), n 501 n 502 and n 503 Each of the following is an independent integer greater than 0 and less than 4, n501 Ra 501 n 502 Ra 502 and n 503 Ra 503 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

[0643] (7) The image forming apparatus according to any one of (1) to (6), wherein the diol unit represented by formula (B) comprises at least one selected from the group consisting of the diol unit (B1) represented by formula (B1), the diol unit (B2) represented by formula (B2), the diol unit (B3) represented by formula (B3), the diol unit (B4) represented by formula (B4), the diol unit (B5) represented by formula (B5), the diol unit (B6) represented by formula (B6), the diol unit (B7) represented by formula (B7), and the diol unit (B8) represented by formula (B8).

[0644] [Chemical Formula 45]

[0645] Formula (B1)

[0646] Formula (B2)

[0647] Formula (B3)

[0648] Equation (B4)

[0649] [Chemical Formula 46]

[0650] Formula (B5)

[0651] Formula (B6)

[0652] Formula (B7)

[0653] Formula (B8)

[0654] In equation (B1), Rb 101 Branched alkyl groups with 4 or more but less than 20 carbon atoms, Rb 201 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 401 、Rb 501 、Rb 801 and Rb 901Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0655] In equation (B2), Rb 102 Rb is a straight-chain alkyl group with 4 or more but less than 20 carbon atoms. 202 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 402 、Rb 502 、Rb 802 and Rb 902 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0656] In equation (B3), Rb 113 and Rb 213 Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where d is an integer between 7 and 15, and Rb 403 、Rb 503 、Rb 803 and Rb 903 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0657] In equation (B4), Rb 104 and Rb 204 Each is independently an alkyl group having 1 or more but less than 3 carbon atoms, Rb 404 、Rb 504 、Rb 804 and Rb 904 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0658] In equation (B5), Ar 105 Rb is an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 205 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 405 、Rb 505 、Rb 805 and Rb 905 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0659] In equation (B6), Rb 116 and Rb 216Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where e is an integer of 4 or more but less than 6, and Rb 406 、Rb 506 、Rb 806 and Rb 906 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0660] In equation (B7), Rb 407 、Rb 507 、Rb 807 and Rb 907 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0661] In equation (B8), Rb 408 、Rb 508 、Rb 808 and Rb 908 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

[0662] (8) The image forming apparatus according to (4), wherein the polyarylate resin and the polycarbonate resin each have a structural unit comprising biphenyl represented by the following formula (BP).

[0663] [Chemical Formula 47]

[0664] Formula (BP)

[0665] In equation (BP), j is an integer greater than 0 and less than 4, and j are R... 1 Each is independently methyl or ethyl, k is an integer greater than or equal to 0 and less than or equal to 4, and k R's are independent of each other. 2 Each can be methyl or ethyl, independently.

[0666] According to the invention involved in (1), compared with the case where the outermost layer of an electrophotographic photoreceptor does not contain a charge transport material, a polyarylate resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B), or a cleaning component having a core rod and a foamed elastic layer spirally disposed on the outer peripheral surface of the core rod, wherein the value of the ratio T / W of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer is less than 0.6 or greater than 1.2, an image forming apparatus with excellent wear suppression of the photoreceptor and contamination suppression of charged components is provided.

[0667] According to the invention involved in (2), an image forming apparatus is provided that has better contamination suppression of charged components compared to cases where the coverage area A of the foamed elastic layer provided on the cleaning component is less than 20% or more than 60%.

[0668] According to the invention involved in (3), an image forming apparatus is provided that has better contamination suppression of the charged component compared to cases where the surface roughness Rz of the charged component is less than 5 μm or more than 10 μm.

[0669] According to the invention involved in (4), compared with the case where the outermost surface layer of the electrophotographic photoreceptor only contains polyarylate resin, an image forming apparatus is provided with superior resistance to wear of the photoreceptor and resistance to contamination of charged parts.

[0670] According to the invention involved in (5), an image forming apparatus is provided that has superior resistance to wear of the photoreceptor and resistance to contamination of charged parts compared to cases where the mass ratio of the polyarylate resin to the polycarbonate resin in the outermost layer of the electrophotographic photoreceptor is less than 3:7 or greater than 7:3.

[0671] According to the invention involved in (6), compared with the case where the dicarboxylic acid unit represented by formula (A) does not include at least one selected from the group consisting of dicarboxylic acid unit (A1) represented by formula (A2), dicarboxylic acid unit (A3) represented by formula (A4), and dicarboxylic acid unit (A5) represented by formula (A5), an image forming apparatus with superior photosensitive wear suppression and charged component contamination suppression is provided.

[0672] According to the invention involved in (7), compared with the case where the diol unit represented by formula (B) does not include at least one selected from the group consisting of diol unit (B1) represented by formula (B1), diol unit (B2) represented by formula (B2), diol unit (B3) represented by formula (B3), diol unit (B4) represented by formula (B4), diol unit (B5) represented by formula (B5), diol unit (B6) represented by formula (B6), diol unit (B7) represented by formula (B7) and diol unit (B8) represented by formula (B8), an image forming apparatus with superior photosensitive wear suppression and charged component contamination suppression is provided.

[0673] According to the invention involved in (8), compared with the case where the polyarylate resin and the polycarbonate resin do not have structural units containing biphenyl represented by the following formula (BP), an image forming apparatus with excellent photoreceptor abrasion suppression is provided.

[0674] The embodiments of the present invention described above are provided for illustrative purposes. Furthermore, these embodiments do not encompass the entirety of the invention, nor do they limit the invention to the disclosed methods. It will be apparent to those skilled in the art that various modifications and variations will be readily understood. These embodiments were chosen and described to most readily explain the principles and applications of the invention. Thus, those skilled in the art can understand the invention through various modifications that are assumed to be optimized for specific uses of various embodiments. The scope of the invention is defined by the foregoing claims and their equivalents.

Claims

1. An image forming apparatus comprising: Electrophotographic photosensitive material, and The charging device includes a charging component that charges the surface of the electrophotographic photoreceptor and a cleaning component disposed in contact with the charging component. The electrophotographic photoreceptor has a conductive substrate and a photosensitive layer disposed on the conductive substrate, and the outermost layer of the electrophotographic photoreceptor comprises a charge transport material and a polyaryl resin having a dicarboxylic acid unit represented by formula (A) and a diol unit represented by formula (B). The cleaning component has a core rod and a foamed elastic layer arranged in a spiral shape on the outer peripheral surface of the core rod. The ratio of the thickness T of the foamed elastic layer to the width W of the foamed elastic layer, T / W, is 0.6 or more and 1.2 or less. [Chemical Formula 1] In equation (A), Ar A1 and Ar A2 Each is an aromatic ring that can have substituents, L A It is a single bond or a divalent linker, n A1 It can be 0, 1, or 2; In equation (B), Ar B1 and Ar B2 Each is an aromatic ring that can have substituents, L B It is a single bond, an oxygen atom, a sulfur atom, or -C(Rb) 1 (Rb) 2 )-,n B1 It can be 0, 1, or 2; Rb 1 and Rb 2 Rb is independently composed of hydrogen atoms, an alkyl group having 1 or more but less than 20 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 1 With Rb 2 They can bond together to form cyclic alkyl groups.

2. The image forming apparatus according to claim 1, wherein, The coverage area A of the foamed elastic layer provided on the cleaning component is 20% or more and 60% or less.

3. The image forming apparatus according to claim 1 or 2, wherein, The surface roughness Rz of the charged component is greater than 5 μm and less than 10 μm.

4. The image forming apparatus according to any one of claims 1 to 3, wherein, The outermost layer of the electrophotographic photoreceptor also contains polycarbonate resin.

5. The image forming apparatus according to claim 4, wherein, The mass ratio of the polyarylate resin to the polycarbonate resin in the outermost layer of the electrophotographic photoreceptor is 3:7 to 7:

3.

6. The image forming apparatus according to any one of claims 1 to 5, wherein, The dicarboxylic acid unit represented by formula (A) comprises at least one selected from the group consisting of dicarboxylic acid units (A1) represented by formula (A2), dicarboxylic acid units (A3) represented by formula (A4), and dicarboxylic acid units (A5) represented by formula (A5). [Chemical Formula 2] In equation (A1), n 101 n is an integer greater than 0 and less than 4. 101 Ra 101 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms; In equation (A2), n 201 and n 202 Each of the following is an independent integer greater than 0 and less than 4, n 201 Ra 201 and n 202 Ra 202 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms; In equation (A3), n 301 and n 302 Each of the following is an independent integer greater than 0 and less than 4, n 301 Ra 301 and n 302 Ra 302 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms; In equation (A4), n 401 n is an integer greater than 0 and less than 6. 401 Ra 401 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms; In equation (A5), n 501 n 502 and n 503 Each of the following is an independent integer greater than 0 and less than 4, n 501 Ra 501 n 502 Ra 502 and n 503 Ra 503 Each is independently an alkyl group having 1 or more but less than 10 carbon atoms, an aryl group having 6 or more but less than 12 carbon atoms, or an alkoxy group having 1 or more but less than 6 carbon atoms.

7. The image forming apparatus according to any one of claims 1 to 6, wherein, The diol unit represented by formula (B) comprises at least one selected from the group consisting of diol units (B1) represented by formula (B2), diol units (B3) represented by formula (B4), diol units (B5) represented by formula (B6), diol units (B7) represented by formula (B7), and diol units (B8) represented by formula (B8). [Chemical Formula 3] [Chemical Formula 4] In equation (B1), Rb 101 Branched alkyl groups with 4 or more but less than 20 carbon atoms, Rb 201 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 401 、Rb 501 、Rb 801 and Rb 901 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom; In equation (B2), Rb 102 Rb is a straight-chain alkyl group with 4 or more but less than 20 carbon atoms. 202 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 402 、Rb 502 、Rb 802 and Rb 902 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom; In equation (B3), Rb 113 and Rb 213 Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where d is an integer between 7 and 15, and Rb 403 、Rb 503 、Rb 803 and Rb 903 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom; In equation (B4), Rb 104 and Rb 204 Each is independently an alkyl group having 1 or more but less than 3 carbon atoms, Rb 404 、Rb 504 、Rb 804 and Rb 904 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom; In equation (B5), Ar 105 Rb is an aryl group having 6 or more but less than 12 carbon atoms, or an aralkyl group having 7 or more but less than 20 carbon atoms. 205 Rb is an alkyl group having 1 or more hydrogen atoms and 3 or fewer carbon atoms. 405 、Rb 505 、Rb 805 and Rb 905 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom; In equation (B6), Rb 116 and Rb 216 Each of the following is independently a hydrogen atom, a straight-chain alkyl group having 1 or more but less than 3 carbon atoms, an alkoxy group having 1 or more but less than 4 carbon atoms, or a halogen atom, where e is an integer of 4 or more but less than 6, and Rb 406 、Rb 506 、Rb 806 and Rb 906 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom; In equation (B7), Rb 407 、Rb 507 、Rb 807 and Rb 907 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom; In equation (B8), Rb 408 、Rb 508 、Rb 808 and Rb 908 Each is independently a hydrogen atom, an alkyl group having 1 or more but less than 4 carbon atoms, an alkoxy group having 1 or more but less than 6 carbon atoms, or a halogen atom.

8. The image forming apparatus according to claim 4, wherein, The polyaryl ester resin and the polycarbonate resin each have structural units comprising biphenyl represented by the following formula (BP). [Chemical Formula 5] In equation (BP), j is an integer greater than 0 and less than 4, and j are R... 1 Each is independently methyl or ethyl, k is an integer greater than or equal to 0 and less than or equal to 4, and k R's are independent of each other. 2 Each can be methyl or ethyl, independently.

Images