Abstract: An electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer arranged on the conductive substrate and containing, as a charge generating material, any one material selected from the group consisting of titanyl phthalocyanines, metal-free phthalocyanines, chlorogallium phthalocyanines and hydroxygallium phthalocyanines; and, as an electron transporting material, a naphthalene tetracarboxylic acid diimide compound represented by Formula (1) below, where R1 and R2 each represent a hydrogen atom, an alkyl group having 1 to 10 carbon atoms, an alkylene group, an alkoxy group, an alkyl ester group, a phenyl group optionally having a substituent, a naphthyl group optionally having a substituent, or a halogen element; and R1 and R2 are optionally the same or different: The photoreceptor realizes a stable print density even in a low-temperature environment by suppressing a reduction in print density that is caused by potential fluctuation of the photoreceptor in the low-temperat

Abstract: To provide a charge transport layer excellent in the external quantum efficiency, and an organic photoelectronic element comprising the charge transport layer. A charge transport layer comprising a film containing a fluorinated polymer and a semiconductor material, wherein the film has a material composition such that ?Eth is within a range of from 0.010 to 0.080 MV/cm. An organic photoelectronic element comprising the charge transport layer.

Abstract: An electrophotographic photosensitive member (1) includes a conductive substrate (2) and a photosensitive layer (3). The photosensitive layer (3) contains a charge generating material and a compound represented by general formula (1) shown below. In general formula (1), R1 and R2 each represent, independently of one another: a C1-20 alkyl group optionally having at least one of a C6-14 aryl group optionally having a substituent and a C2-20 alkoxycarbonyl group; a C6-14 aryl group optionally having a C1-20 alkyl group; a C3-10 cycloalkyl group; or a C1-6 alkoxy group.

Abstract: An organic light-emitting device including a first electrode; a second electrode facing the first electrode; and an organic layer between the first electrode and the second electrode, the organic layer including an emission layer, wherein the organic layer includes a compound represented by Formula 1: When the compound represented by Formula 1 is used as electron-transporting material, an organic light-emitting device including this compound may show significantly improved efficiency, driving voltage, high luminance, and long lifespan characteristics.

Abstract: The present disclosure provides reactive quencher dyes that can be used in the detection and/or quantification of desirable target molecules, such as proteins, nucleic acids and various cellular organelles. These dyes are essentially non-fluorescent but are efficient quenchers of various fluorescent dyes. Also, provided are methods of using the dyes, bio-probes incorporating dyes and methods of using the bio-probes. The quencher dyes described herein are modified to provide beneficial properties.

Abstract: Disclosed herein are gemini surfactants, and methods for making and using these gemini surfactants. These gemini surfactants may be incorporated in paints and coatings to provide hydrophilic and/or self-cleaning properties.

Abstract: A positively chargeable single-layer electrophotographic photosensitive member includes a conductive substrate and a photosensitive layer. The photosensitive layer contains at least a charge generating material, a hole transport material, an electron transport material, and an electron accepting compound. The hole transport material includes a benzidine derivative. The electron transport material includes at least one compound selected from the group consisting of compounds represented by general formulae (1), (2), (3), and (4) shown below. The electron accepting compound includes at least one compound selected from the group consisting of compounds represented by general formulae (5) and (6) shown below.

Abstract: The present invention provides an organic thin film light emitting device having high luminous efficiency and durable life realized by using a benzindolocarbazole derivative as represented by either general formula (1-1) or (1-2) given below: [Chemical compound 1] wherein R1 to R24 may be identical to or different from each other and are selected from the group consisting of a hydrogen atom, alkyl group, cycloalkyl group, heterocyclic group, amino group, alkenyl group, cycloalkenyl group, alkynyl group, alkoxy group, alkylthio group, aryl ether group, aryl thioether group, aryl group, heteroaryl group, halogen atom, carbonyl group, carboxyl group, oxycarbonyl group, carbamoyl group, silyl group, and —P(?O)R25R26; R25 and R26 represent either an aryl group or a heteroaryl group; R25 and R26 may be condensed to form a ring; L1 to L4 independently represent a single bond, a substituted or unsubstituted arylene group, or a substituted or unsubstituted heteroarylene group; and A1 to A4 independently represent an a

Abstract: Provided are a curable composition for an organic electroluminescent element, which has high light emission efficiency and is applicable to a wet process, a cured product thereof, and an organic electroluminescent element containing the cured product in an organic layer. More specifically, provided are a curable composition containing a compound represented by an indolocarbazole skeleton compound, a cured product obtained by curing the curable composition, and an organic electroluminescent element containing the cured product in an organic layer.

Abstract: An electronic device includes a first electrode and a second electrode which are separately formed on a base; a functional layer which includes an organic semiconductor material layer, and is formed on the base between the first electrode and the second electrode; a functional layer extension portion which includes the organic semiconductor material layer, and extends from the functional layer; a protective film which is formed at least on the functional layer; and an insulating layer which covers an entire surface, in which the protective film is patterned to include at least two sides which intersect with each other at an acute angle, and a vertex portion of the protective film in which the two sides intersect with each other, is chamfered.

Abstract: An electrophotographic photosensitive member includes a photosensitive layer containing a naphthalenediimide derivative represented by the following formula (1) or (2). In the formula (1) or (2), R1 represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms and optionally having an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

Abstract: Disclosed herein is a method for electrophotographic printing, the method comprising: transferring, separately, from a photo imaging plate, a plurality of images formed from different colored electrostatic ink compositions to an intermediate transfer member to form a print image on the intermediate transfer member; providing a print substrate that has been wetted with a protic solvent; transferring the print image to the print substrate. Also disclosed herein is an apparatus for electrophotographic printing.

Abstract: Provided is an electrophotographic photosensitive member including a charge-generating layer that includes: an amine compound represented by the formula (1) and a gallium phthalocyanine crystal, or a gallium phthalocyanine crystal containing the amine compound represented by the formula (1); and an arene compound, in which the arene compound includes at least one compound selected from the group consisting of a compound represented by the formula (2) and a compound represented by the formula (3).

Abstract: An electrophotographic photosensitive member includes a photosensitive layer containing a naphthalenediimide derivative represented by the following general formula (1). In the general formula (1), R1 represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms and optionally having an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. R2 and R3, independently from each other, each represent an alkyl group having 1 to 4 carbon atoms, a halogen group, or a cyano group.

Abstract: An electrophotographic photoconductor including, in the order recited: a conductive substrate; an undercoat layer provided on the conductive substrate; and a photoconductive layer provided on the undercoat layer and containing at least a phthalocyanine compound as a charge generation material and, as a resin binder, a polyvinyl acetal resin composed of a repeating unit represented by formula (1): where, in formula (1), R is a hydrogen atom, a methyl group, an ethyl group or a propyl group; x, y and z represent mol % of the respective structural units, where x+y+z=100; n is an integer from 1 to 5; a degree of acetalization (x+z) is 86 to 99 mol %; and a molar ratio (x:z) of the structural units is 95:5 to 50:50.

Abstract: An electrophotographic photosensitive member includes a photosensitive layer containing a naphthalenediimide derivative represented by the following formula (1) or (2). In the formula (1) or (2), R1 represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms and optionally having an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms.

Abstract: An electrophotographic photosensitive member includes a photosensitive layer containing a naphthalenediimide derivative represented by the following general formula (1). In the general formula (1), R1 represents an alkyl group having 1 to 10 carbon atoms, an aryl group having 6 to 12 carbon atoms and optionally having an alkyl group having 1 to 10 carbon atoms, an aralkyl group having 7 to 12 carbon atoms, a cycloalkyl group having 3 to 10 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms. R2 and R3, independently from each other, each represent an alkyl group having 1 to 4 carbon atoms, a halogen group, or a cyano group.

Abstract: An electrophotographic photosensitive member, including a support, a charge generating layer on the support, and a charge transporting layer on the charge generating layer, wherein the charge generating layer includes a gallium phthalocyanine crystal, a nitrogen-containing heterocyclic compound having a nitrogen atom having a substituent, and a compound represented by Formula (1) or (2).

Abstract: An electrophotographic photosensitive member includes a laminated body including a conductive support, a first intermediate layer on the conductive support, and a second intermediate layer on the first intermediate layer, the first intermediate layer containing a binder resin and a metal oxide particle whose surface have been treated with an organic compound, and the second intermediate layer containing a cured product having electron transportability, in which the laminated body satisfies the following expression (1): R—nV/R_0V?0.

Abstract: An electrophotographic photosensitive member, comprising a support, a charge generating layer on the support and a charge transporting layer on the charge generating layer, wherein the charge generating layer comprises a gallium phthalocyanine crystal, a nitrogen-containing heterocyclic compound and a compound represented by Formula (1), wherein a nitrogen atom in a heterocyclic ring of the nitrogen-containing heterocyclic compound has a substituent.

Abstract: Provided is an electrophotographic photosensitive member which is excellent in terms of both continuous reduction of contact stress with contact members and the like and potential stability during repeated use. A charge transport layer which serves as a surface layer of an electrophotographic photosensitive member has a matrix-domain structure including a matrix containing a component [?] (polycarbonate resin D having a specific repeating structural unit) and a charge-transporting substance and domains containing a component [?] (polycarbonate resin A having a repeating structural unit including a specific siloxane moiety).

Abstract: The invention relates to novel compounds as ligands for transition metal complexes and materials made thereof that can be used, for example, as emitters in organic light-emitting electrochemical cells (OLEECs). According to the invention, non-fluorinated electron-poor emitter materials are disclosed for the first time that can be used in organic light-emitting electrochemical cells.

Abstract: An image bearing member including an electroconductive substrate, and a photosensitive layer provided overlying the electroconductive substrate, the photosensitive layer containing at least one charge transport materials selected from the group consisting of a naphthalene tetracarboxylic acid diimide-isoindol derivative represented by the following chemical structure 1, a naphthalimide-isoindol derivative represented by the following chemical structure 2, and a triphenyl amine-isoindol derivative represented by the following chemical structure 3, where R1 and R2 independently represent a hydrogen atom, a substituted or non-substituted alkyl group, an alkoxy group, a substituted or non-substituted aromatic hydrocarbon group, a halogen atom, and a nitro group, k represents an integer of 1 to 4, and l represents an integer of from 1 to 5 and R3 represents a substituted or non-substituted alkyl group, a substituted or non-substituted cycloalkyl group, and a substituted or non-substituted aromatic hydrocarbo

Abstract: In order to provide an electrophotographic photosensitive member with which a ghost is suppressed even under a low temperature and low humidity environment, and a process cartridge and an electrophotographic apparatus having the electrophotographic photosensitive member, the electrophotographic photosensitive member has a support, an undercoat layer formed on the support, and a photosensitive layer formed on the undercoat layer and comprising a charge generating material and a hole transporting material, wherein the undercoat layer comprises a particular amine compound.

Abstract: An electrophotographic photosensitive member comprises a charge-transporting layer which is a surface layer of the electrophotographic photosensitive member; wherein the charge-transporting layer has a matrix-domain structure having: a matrix comprising a component [?] and a component [?] (charge-transporting substances having specific structures), and a domain comprising a component [?](resin [?1], or resin [?1] and resin [?2]).

Abstract: A positively chargeable electrophotographic photosensitive member has a photosensitive layer. The photosensitive layer at least includes the following layers layered in the stated order: (I) a charge transport layer at least containing a hole transport material and a binder resin; and (II) a charge generating-and-transporting layer at least containing a charge generating material, an electron transport material, a hole transport material, and a binder resin all within this layer. The binder resin contained in the charge transport layer is different from the binder resin contained in the charge generating-and-transporting layer, and either of the binder resins contains a polyvinyl acetal resin.

Abstract: Provided is an electrophotographic photosensitive member including a charge-generating layer that includes: an amine compound represented by the formula (1) and a gallium phthalocyanine crystal, or a gallium phthalocyanine crystal containing the amine compound represented by the formula (1); and an arene compound, in which the arene compound includes at least one compound selected from the group consisting of a compound represented by the formula (2) and a compound represented by the formula (3).

Abstract: Provided is an image holding member for an image forming apparatus including a support; and a photosensitive layer disposed on the support and containing a compound represented by the following formula (I): wherein in the formula (I), R1's each independently represent a substituted or unsubstituted, linear or branched alkyl group having from 1 to 8 carbon atoms; Ar's each independently represent a substituted or unsubstituted phenyl group, a substituted or unsubstituted monovalent polynuclear aromatic hydrocarbon group having two aromatic rings, a substituted or unsubstituted monovalent condensed aromatic hydrocarbon group having two or three aromatic rings, or a substituted or unsubstituted monovalent aromatic heterocyclic group; and n's each independently represent a number of from 0 to 7.

Abstract: A photoconductor containing an optional anticurl layer, a supporting substrate, an optional ground plane layer, an optional hole blocking layer, an optional adhesive layer, a photogenerating layer, a charge transport layer, and an overcoat layer mixture of a charge transport compound, a melamine resin, an optional acid catalyst, and a fluoro component.

Abstract: A single-layer-type electrophotographic photosensitive member includes a layer disposed on an electrically conductive substrate, the layer including at least a charge-generating material, an electron transport material, a hole transport material, and a binder resin within the same layer. The charge-generating material contains a phthalocyanine pigment and N-type pigments including at least a perylene-based pigment and an azo-based pigment, and the total amount of the N-type pigments is 0.03 to 10 parts by mass relative to 1 part by mass of the phthalocyanine pigment.

Abstract: An electrophotographic photoreceptor includes a conductive substrate; and a photosensitive layer on the conductive substrate, wherein a layer having an outermost surface of the photoreceptor contains a polymer that is formed by polymerizing a crosslinkable charge transport material having an aromatic group and a —CH2OH group, and the layer having the outermost surface satisfies the following Formula (1): (Peak 2)/(Peak 1)?0.05??(1) wherein Peak 1 represents a peak area of an absorption peak (from about 1550 cm?1 to about 1650 cm?1) of stretching vibration of an aromatic group, which is obtained when an infrared absorption spectrum of the layer having the outermost surface is measured, and Peak 2 represents a peak area of an absorption peak (from about 1670 cm?1 to about 1710 cm?1) of an aromatic aldehyde, which is obtained when the infrared absorption spectrum of the layer having the outermost surface is measured.

Abstract: When an abutting pressure of the cleaning blade on a photoreceptor is increased, a chattering occurs due to the so-called a stick-slip phenomenon that the blade repeatedly undergoes sticking to the outermost surface of the photoreceptor and slipping thereon. As a result, a possibility of noise generation becomes higher and there is a possibility that toner particles might pass through during slipping to cause a cleaning failure, resulting in a streaky image defect. There is also a higher possibility that the so-called a filming phenomenon might occur, in which a component of the toner sticks to the photoreceptor surface by the action of the blade pressure and becomes difficult to remove, so as to lead to persistent image defects. Furthermore, since the photoreceptor is rotated with toners in the state of being strongly pressed thereagainst, the image defects are apt to be caused due to peripheral-direction scratches.

Abstract: According to the invention, there is provided an electrophotographic photoreceptor comprising a conductive substrate and a photosensitive layer provided on a surface of the conductive substrate, an outermost layer of the photosensitive layer containing a crosslinked product composed of a guanamine compound and at least one charge transporting material having at least one substituent selected from the group consisting of —OH, —OCH3, —NH2, —SH, and —COOH.

Abstract: An image holding member for an image forming apparatus includes: a substrate; and a photosensitive layer on the substrate, the photosensitive layer containing a compound including a partial structure represented by the following Formula (II-2) wherein in Formula (II-2), Ar represents a substituted or unsubstituted phenyl group, a substituted or unsubstituted monovalent polynuclear aromatic hydrocarbon group having from 2 to 10 aromatic rings, a substituted or unsubstituted monovalent condensed aromatic hydrocarbon group having from 2 to 10 aromatic rings, or a substituted or unsubstituted monovalent aromatic heterocyclic group; q represents 0 or 1; and n's each independently represent an integer of from 0 to 7.

Abstract: The present invention is to provide a charge transport substance having high resistance to stress within electrophotographic processes, an electrophotographic photoreceptor which has excellent high-speed responsiveness, shows a sufficient residual potential, and has high resistance to stress within electrophotographic processes, an electrophotographic cartridge, and an image-forming apparatus. The invention provides a charge transport substance having a specific structure. The invention further provides an electrophotographic photoreceptor including a photosensitive layer which contains the charge transport substance having a specific structure, an electrophotographic cartridge, and an image-forming apparatus, equipped with this electrophotographic photoreceptor.

Abstract: A imaging member, such as a photoreceptor, having an outermost layer that is a structured organic film (SOF) comprising a plurality of segments and a plurality of linkers including a first fluorinated segment, a second electroactive segment and fluorinated secondary components.

Abstract: To provide: a latent electrostatic image bearing member including one of a cured material obtained through radical polymerization of a radically polymerizable compound of component (A1), and a cured material obtained through radical polymerization of a radically polymerizable compound of component (A2) in the outermost layer, wherein the component (A1) includes two radically polymerizable groups and a substituted amino group which does not include a radically polymerizable group in a molecule, and the radically polymerizable group and the nearest substituted amino group which does not include an unsaturated bond in between are connected with two or more aromatic hydrocarbon compounds, and, the radically polymerizable compound of component (A2) includes a condensed polycyclic aromatic hydrocarbon formed by bonding a radically polymerizable group and a non-radically polymerizable substituted amine group through a condensed polycyclic aromatic hydrocarbon group; and an image forming apparatus, image forming meth

Abstract: To provide an electrophotographic photoreceptor having a high sensitivity, a good balance of various electric properties such as chargeability and residual potential, a good stability of the coating solution, and an excellent light resistance. An electrophotographic photoreceptor comprising an electroconductive support having thereon a photosensitive layer, wherein the photosensitive layer contains a compound represented by the following formula (1): (wherein R1 represents a group having a chiral center, R2 represents a hydrogen atom, an alkyl group which may have a substituent, or an aryl group which may have a substituent, R3 and R4 each independently represents an alkylene group which may have a substituent, or an arylene group which may have a substituent, and R5, R6, R7 and R8 each independently represents an alkyl group which may have a substituent, or an aryl group which may have a substituent, and at least one member of R5 to R8 is an aryl group having a substituent).

Abstract: An electrophotographic photoconductor including: an electrically conductive substrate; and at least a photoconductive layer thereon, wherein the photoconductive layer contains a diazapentadiene derivative represented by general formula (1): where “X” represents general formula (a), (b) or (c); “R1” and “R2” each represent substituted or unsubstituted alkyl group or aromatic hydrocarbon group, and may be the same or different; “R1” and “R2” may be joined together via “Y” to form a ring; “Y” represents single bond, oxygen atom, —CH2CH2—, or —CH?CH—, where “R3” represents substituted or unsubstituted alkyl group, aromatic hydrocarbon group, alkoxy group, alkoxycarbonyl group, or halogen group; “R4” represents substituted or unsubstituted alkyl or aromatic hydrocarbon group; “n” represents integer ranging from 0 to 4; and when “n” is integer of 2 to 4, “R3” may be the same or different.

Abstract: An electrophotographic photoreceptor includes a conductive substrate; a single-layer photosensitive layer that is provided on the conductive substrate and includes a binder resin, a charge generation material, a hole transport material, and an electron transport material, wherein a half decay exposure during positive charging is less than or equal to 0.18 ?J/cm2, and a half decay exposure during negative charging is 2 to 12 times the half decay exposure during positive charging.

Abstract: A photoconductor containing an optional supporting substrate, a photogenerating layer, and at least one charge transport layer comprised of at least one charge transport component, and wherein the photogenerating layer contains a hydroxygallium phthalocyanine, a hydroxyaluminum phthalocyanine, a polymeric binder, and a silanol.

Abstract: An electrophotographic photoreceptor includes: a conductive substrate; a photosensitive layer including a charge-generating layer containing a charge-generating material and a charge-transporting layer containing a charge-transporting material, the charge-transporting layer having a hole mobility of about 5.0×10?6 (cm2/V·sec) or less at an electric field of 2 V/cm; and an overcoat layer that is provided on the photosensitive layer and contains a cured material of a charge-transporting material, wherein relational expression (1) Ip(OCL)>Ip(CTL)>Ip(CGL) is satisfied wherein Ip(CGL) represents an ionization potential (eV) of the charge-generating material contained in the charge-generating layer; Ip(CTL) represents an ionization potential (eV) of the charge-transporting material contained in the charge-transporting layer; and Ip(OCL) represents an ionization potential (eV) of the charge-transporting material contained in the overcoat layer.

Abstract: An electrophotographic photoconductor including a conductive support, a charge generating layer, a hole transporting layer, and a hole transporting-protective layer, these layers being laminated in this order on the conductive support, wherein the hole transporting-protective layer contains a three-dimensionally crosslinked product which is obtained through chain polymerization of at least a radical polymerizable hole-transporting compound by irradiating the radical polymerizable hole-transporting compound with an active energy beam, and wherein the hole transporting-protective layer contains an oxazole compound represented by General Formula (1) or (2) below:

Abstract: An image forming apparatus including at least an image bearing member having a substrate having a photosensitive layer thereon, the image bearing member to bear a latent electrostatic image on a surface thereof, a charging device to the surface of the image bearing member, an irradiation device to irradiate the surface of the image bearing member with light to form a latent electrostatic image thereon, a development device to develop the latent electrostatic with toner to obtain a developed image, a transfer device to transfer the developed image to a recording medium, and a cleaning device to clean the surface of the image bearing member, wherein the photosensitive layer includes naphthalene tetracarbonic acid diimide derivative as a charge transport material represented by the following Chemical Structure (1): In the Chemical Structure (1), Z represents a group represented by the following Chemical Formula (1): or the following Chemical Formula (2): —R9??Chemical Formula (2).

Abstract: An organic, semiconducting material, in particular, a material which can be used as a semiconductor material in organic electronics.

Abstract: An electrophotographic photoreceptor including a conductive substrate and a photosensitive layer overlying the conductive substrate. The photosensitive layer comprises a phthalimide isoindole derivative having a specific chemical formula.

Abstract: The present invention provides a naphthalenetetracarboxylic acid diimide derivative represented by the following general formula (1): wherein R1 and R2, which are identical or different, each represent a substituted or non-substituted alkyl group or a substituted or non-substituted aromatic hydrocarbon group; R3 represents an alkyl group having 1 to 8 carbon atoms or an aromatic hydrocarbon group; R4, R5, R6 and R7, which are identical or different, each represent a hydrogen atom, a substituted or non-substituted alkyl group, or a substituted or non-substituted aromatic hydrocarbon group; and R1 and R2 may be linked to form a substituted or non-substituted heterocyclic group including a nitrogen atom; with compounds where all of R1, R2 and R3 are a methyl group, and compounds where both of R1 and R2 are a methyl group and R3 is a 1-octyl group being excluded.

Abstract: The presently disclosed embodiments relate in general to electrophotographic imaging members, such as layered photoreceptor structures, and processes for making and using the same. More particularly, the embodiments pertain to the incorporation of a liquid compound having a high boiling point into the charge transport layer such that an anticurl back coating is no longer needed for reduction or elimination of photoreceptor layer curling.

Abstract: The presently disclosed embodiments relate in general to electrophotographic imaging members, such as layered photoreceptor structures, and processes for making and using the same. More particularly, the embodiments pertain to the incorporation of a liquid compound having a high boiling point into the charge transport layer such that an anticurl back coating is no longer needed for reduction or elimination of photoreceptor upward curling.

Abstract: An N-phenyl-diphenylisoindole derivative having the following formula (I): wherein each of R1 and R2 represents a hydrogen atom, a substituted or an unsubstituted alkyl group, a substituted or an unsubstituted alkoxy group, a substituted or an unsubstituted phenyl group, or a substituted or an unsubstituted phenoxy group; R3 represents a hydrogen atom, a substituted or an unsubstituted alkyl group, a substituted or an unsubstituted alkoxy group, a substituted or an unsubstituted phenyl group, a substituted or an unsubstituted phenoxy group, or has the following formula (2): wherein each of R4 and R5 represents a substituted or an unsubstituted alkyl group, or a substituted or an unsubstituted phenyl group; 1 represents an integer of from 1 to 4; and each of m and n represents an integer of from 1 to 5.