JP2011026575A - Polycarbonate copolymer, coating liquid using the same, and electrophotographic photosensitive article - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate copolymer excellent in solubility to an organic solvent and wear-resistance, a coating liquid using it, and an electrophotographic photosensitive article using it. <P>SOLUTION: The polycarbonate copolymer includes a structure comprising a repetition unit of formula (1) and has a mole copolymerization composition represented by Ar<SP>2</SP>/(Ar<SP>1</SP>+Ar<SP>2</SP>) of 25-47 mol%. In formula (1), Ar<SP>1</SP>represents a specific group having two phenyl rings, Ar<SP>2</SP>represents a divalent group derived from a substituted or non-substituted biphenol or the like, and n is the average repetition number of Ar<SP>1</SP>block. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a polycarbonate copolymer, a coating solution using the same, and an electrophotographic photosensitive member.

  Polycarbonate resins are excellent in mechanical properties, thermal properties, and electrical properties, and thus have been used as raw materials for molded products in various industrial fields. In recent years, it has been frequently used in the field of functional products that also utilize the optical properties of the polycarbonate resin. With the expansion of such application fields, the required performance for polycarbonate resins has also diversified.

An example of a functional product is an electrophotographic photoreceptor using a polycarbonate resin as a binder resin for a functional material such as a charge generation material or a charge transport material.
The electrophotographic photosensitive member is required to have predetermined sensitivity, electrical characteristics, and optical characteristics according to the applied electrophotographic process. In this electrophotographic photoreceptor, operations such as corona charging, toner development, transfer to paper, and cleaning treatment are repeatedly performed on the surface of the photosensitive layer. Therefore, an electric and mechanical external force is applied each time these operations are performed. Added. Therefore, in order to maintain the electrophotographic image quality for a long period of time, the photosensitive layer provided on the surface of the electrophotographic photosensitive member is required to have durability against these external forces.
In addition, electrophotographic photoreceptors are usually manufactured by a method in which a binder resin is dissolved in an organic solvent together with a functional material and cast onto a conductive substrate, so that the solubility in an organic solvent and the stability of the solution are increased. Is required.

  Conventionally, 2,2-bis (4-hydroxyphenyl) propane (bisphenol A), 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z), or the like is used as a raw material as a binder resin for an electrophotographic photoreceptor. Polycarbonate resins have been used, but were not fully satisfactory in terms of durability such as wear resistance. Therefore, various methods have been taken to meet such demands. As one effective technique, copolymerized polycarbonate is known (for example, see Patent Documents 1 and 2).

In the resin described in Patent Document 1, a polycarbonate copolymer is produced by copolymerizing a component having a biphenol skeleton contributing to abrasion resistance with a component having a bisphenol Z skeleton contributing to solubility. As a result, the abrasion resistance is better than that of the type polycarbonate homopolymer.
Patent Document 2 discloses an alternating copolymerized polycarbonate of bisphenol A and biphenol as a polymer using a raw material with a reduced number of oligomers and increasing the copolymerization ratio of biphenol. The copolymerization ratio of biphenol in the alternating copolymer is 50 mol%.

Japanese Patent Laid-Open No. 4-17961 Japanese Patent Laid-Open No. 5-70582

However, in the above-mentioned polycarbonate copolymer described in Patent Document 1, the content of the biphenol component that contributes to the improvement of wear resistance is that the oligomer having a chloroformate group at the molecular end as a raw material is a 2- to 4-mer. For some reason, the proportion of the copolymer is about 23 mol%. Therefore, in order to increase the content of the biphenol component, a method of producing a polycarbonate copolymer by producing a biphenol oligomer by an interfacial method and copolymerizing this oligomer with bisphenol A or bisphenol Z was attempted. In the production stage, insoluble components were precipitated and synthesis was impossible, and it was not possible to proceed to the stage of copolymerizing bisphenol A or bisphenol Z. In addition, in order to increase the content of the biphenol component, bisphenol A or bisphenol Z and biphenol are mixed to produce an oligomer by the interfacial method, and then polymerized to produce a polycarbonate copolymer. There was a problem that the solution obtained by dissolving in a solvent became cloudy. Furthermore, when this solution was used as a coating solution to produce an electrophotographic photosensitive member, the electrophotographic photosensitive member had poor electrical characteristics.
In addition, since the resin disclosed in Patent Document 2 is an alternating copolymer, it has been reported that the polymer structure is less disturbed, and the obtained polymer is crystalline, resulting in low solubility. It was.

  Accordingly, an object of the present invention is to provide a polycarbonate copolymer excellent in abrasion resistance while maintaining solubility in an organic solvent, a coating solution using the same, and an electrophotographic photosensitive member using the same. And

As a result of earnest research to solve the above-mentioned problems, when the raw material is an oligomer with a small number of bisphenol compounds having an alicyclic group in the main chain skeleton, which is thought to contribute to improvement in solubility, and homopolymerized In addition, by reacting a dihydric phenol with a specific structure, which has high crystallinity and produces a polymer that is insoluble in the solvent and polymerization does not proceed, and only a low molecular weight product is obtained, it can be used in an organic solvent. It has been found that a polycarbonate copolymer having the characteristics of improved wear resistance can be obtained while maintaining excellent solubility.
That is, the present invention provides the following polycarbonate copolymer, a coating solution using the same, and an electrophotographic photosensitive member.
[1] It has a structure composed of a repeating unit represented by the following formula (1), and the molar copolymer composition represented by Ar ² / (Ar ¹ + Ar ² ) is 25 mol% or more and 47 mol% or less. Polycarbonate copolymer characterized by

{In the formula, Ar ¹ is a group represented by the following formula (2); Ar ² is a substituted or unsubstituted biphenol, dihydroxynaphthalene, hydroquinone, resorcin, catechol, 9,9-bis (hydroxyphenyl) fluorene. Or a divalent group derived from 4,4′-dihydroxydiphenylmethane. n is the average number of repetitions of Ar ¹ block and represents a number of 1.09 or more and 3.00 or less. }

{Wherein, R ^1, R ² is a hydrogen atom, a halogen atom, a trifluoromethyl group, an alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, 1 to 12 carbon atoms An alkoxy group, a substituted or unsubstituted aryloxy group having 6 to 12 carbon atoms. In R ¹ and R ² , a plurality of groups may be added to one aromatic ring. In this case, the plurality of groups may be the same or different from each other. X represents a substituted or unsubstituted cycloalkylidene group having 5 to 20 carbon atoms, a substituted or unsubstituted bicyclo or tricyclohydrocarbon diyl group having 5 to 20 carbon atoms, or a group represented by the following formula (3). . }

(Wherein R ^{5 to} R ⁷ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a trifluoromethyl group, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.)

[2] The polycarbonate copolymer according to the above [1], further comprising a divalent organosiloxane-modified phenylene group as Ar ² .
[3] The polycarbonate copolymer according to [2] above, wherein the divalent organosiloxane-modified phenylene group is preferably a group represented by the following formula (2A) or (2B).

(In Formula (2A), R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or a carbon number of 6 to 6). 12 substituted or unsubstituted aryl groups are shown.
R ²³ is each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
n1 is an integer of 2 to 4, and n2 is an integer of 1 to 600. )

(In formula (2B), each R ³¹ is independently a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or a 6 to 12 carbon number. These are substituted or unsubstituted aryl groups.
R ³² is each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
R ³³ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond.
R ³⁴ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond.
Y and Y ′ are an alkylene group having 2 or more carbon atoms, an alkyleneoxyalkylene, or an oxygen atom.
na is 0 or 1, nb is 1 or 2, and nc is 1 or 2. However, na + nb + nc is 3.
n1 to n4 are each an integer of 0 or more, the sum of n1, n2, n3, and n4 is an integer of 2 to 600, and the sum of n3 and n4 is an integer of 1 or more.
a is 0 or an integer from 1 to 4. )

[4] The polycarbonate copolymer according to any one of [1] to [3], wherein the chain end is sealed with a monovalent aromatic group or a monovalent fluorine-containing aliphatic group. Characteristic polycarbonate copolymer.
[5] The polycarbonate copolymer according to [4] above, wherein the monovalent aromatic group at the chain end is preferably a monovalent organosiloxane-modified phenyl group.
[6] The polycarbonate copolymer according to [5], wherein the monovalent organosiloxane-modified phenyl group is preferably a group represented by the following formula (2C).

(Z is a C2-C6 hydrocarbon group.
R ⁴¹ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms.
R ^{42 to} R ⁴⁵ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted group having 6 to 12 carbon atoms. An aryl group.
R ^{46 to} R ⁴⁹ are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
n is a number of 2 to 600, and indicates the average number of repeating units when it has a molecular weight distribution. )

  [7] The polycarbonate copolymer according to any one of [1] to [6], wherein a bischloroformate oligomer represented by the following formula (4) is used as a raw material, and an average of the bischloroformate oligomers A polycarbonate copolymer having a number of monomers (n ′) of 1.0 or more and 1.99 or less.

[8] The polycarbonate copolymer according to any one of [1] to [7], wherein Ar ¹ represented by the formula (2) is 1,1-bis (4-hydroxyphenyl) cyclohexane. 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclododecane, 2,2-bis (4-hydroxyphenyl) adamantane, 1,3-bis (4- Hydroxyphenyl) adamantane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, or a divalent group derived from a group selected from the group represented by formula (3) A polycarbonate copolymer, characterized in that

[9] The polycarbonate copolymer according to [7] or [8] above, wherein the amide compound is contained in the raw material containing the bischloroformate oligomer represented by the formula (4), The content of the compound is determined based on the mass of nitrogen atoms contained in the raw material containing the bischloroformate oligomer, and is 700 mass ppm or less based on the total mass of the raw material containing the bischloroformate oligomer excluding the solvent. Preferably there is.
[10] The polycarbonate copolymer according to any one of [1] to [9] above, wherein when the polycarbonate copolymer contains a dialkylcarbamic acid chloride, the dialkylcarbamic acid chloride is contained. The amount is preferably 100 mass ppm or less based on the total mass of the polycarbonate copolymer.

[11] A coating solution comprising the polycarbonate copolymer according to any one of [1] to [10] above and an organic solvent.
[12] An electrophotographic photoreceptor having a photosensitive layer provided on a conductive substrate, comprising the polycarbonate copolymer according to any one of [1] to [10] as a component of the photosensitive layer. An electrophotographic photoreceptor characterized by the above.

According to the present invention, when the polycarbonate copolymer is a unit derived from a low-molecular-weight oligomer of a bisphenol compound having an alicyclic group in the main chain skeleton, and a homopolymer, the polycarbonate copolymer is highly specified. A molar copolymer composition represented by Ar ² / (Ar ¹ + Ar ² ) having a unit derived from a dihydric phenol monomer having a structure as a repeating unit is 25 mol% or more and 47 mol% or less. Thus, this polycarbonate copolymer good solubility in organic solvents derived from Ar ¹ unit, and Ar ² have units together both high abrasion resistance derived from, in particular Ar ² each other It is possible to prevent a decrease in solubility due to the presence of the repeating unit and to exhibit high solubility in an organic solvent of Ar ¹ and high wear resistance of Ar ² .

Details of the polycarbonate copolymer of the present invention (hereinafter also simply referred to as “PC copolymer”), a coating solution using this PC copolymer, and an electrophotographic photoreceptor using this coating solution are described in detail below. Explained.
[Structure of PC copolymer]
The PC copolymer of the present invention has a structure composed of repeating units represented by the following formula (1), and a molar copolymer composition represented by Ar ² / (Ar ¹ + Ar ² ) is 25 mol% or more and 47 It is a polycarbonate copolymer characterized by having a mol% or less.

{In the formula, Ar ¹ is a group represented by the following formula (2); Ar ² is a substituted or unsubstituted biphenol, dihydroxynaphthalene, hydroquinone, resorcin, catechol, 9,9-bis (hydroxyphenyl) fluorene. Alternatively, it is a divalent group derived from 4,4′-dihydroxydiphenylmethane. n is the average number of repetitions of Ar ¹ block and represents a number of 1.09 or more and 3.00 or less. }

Since the PC copolymer of the present invention is usually produced by forming an Ar ¹ block and then reacting with a monomer containing Ar ² , n is not a number of 1.0 or less. n is preferably 1.09 or more and 3.00 or less, more preferably 1.09 or more and 2.50 or less. If it is less than 1.09, the regularity of the repeating unit becomes too high, and the characteristics of the crystalline monomer are increased, and the solubility may be deteriorated. On the other hand, if it exceeds 3.00, it is difficult to sufficiently increase the content of the crystalline component contained in the obtained PC copolymer, and the effect of improving the wear resistance may be insufficient.

In the PC copolymer of the present invention, the content of Ar ² monomer units is 25 mol% or more and 47 mol% or less, preferably 29 mol% or more and 47 mol% or less, more preferably 32 mol% or more and 47 mol% or less. Especially preferably, it is 38 mol% or more and 45 mol% or less.
When Ar ² exceeds 47 mol%, a copolymer having a structure with high regularity similar to alternating copolymerization is obtained, so that the solubility in an organic solvent is reduced when wet molding is employed. If it is less than 25 mol%, the effect of improving the wear resistance is not sufficient. The above mol% ^is a value showing a molar copolymer composition represented by ^{Ar 2 / (Ar 1 + Ar} 2) a percentage.
A block copolymer having a structure in which each of Ar ¹ and Ar ² has a single block has low solubility of a block component composed of Ar ² , and therefore a polymer solution dissolved in an organic solvent may become cloudy. It is not preferable.

In the formula (1), Ar ¹ is represented by the following formula (2).

[Wherein, R ¹ and R ² are a hydrogen atom, a halogen atom, a trifluoromethyl group, an alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, or 1 to 12 carbon atoms. An alkoxy group, a substituted or unsubstituted aryloxy group having 6 to 12 carbon atoms. In R ¹ and R ² , a plurality of groups may be added to one aromatic ring. In this case, the plurality of groups may be the same or different from each other. X represents a substituted or unsubstituted cycloalkylidene group having 5 to 20 carbon atoms, a substituted or unsubstituted bicyclo or tricyclohydrocarbon diyl group having 5 to 20 carbon atoms, or a group represented by the following formula (3). . ]

(Wherein R ^{5 to} R ⁷ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a trifluoromethyl group, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms)

As the structure of the formula (2), the structure of the following formula (2 ′) is preferable from the viewpoint of availability of raw materials and solubility. In terms of availability and solubility of raw materials, R ¹ , R ² , R ⁵ , R ⁶ , and R ⁷ are each a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, or a substitution having 6 to 12 carbon atoms. Or an unsubstituted aryl group is preferable.

Examples of the halogen atom constituting R ¹ and R ² include a fluorine atom, a chlorine atom, and a bromine atom.
Examples of the alkyl group having 1 to 12 carbon atoms constituting R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ include straight-chain alkyl or branched alkyl. For example, a methyl group, an ethyl group, various propyl groups, various butyl groups, various pentyl groups, and various hexyl groups. Moreover, cyclic alkyl, such as a cyclohexyl group, may be sufficient. Furthermore, some or all of the hydrogen atoms in these groups may be substituted with halogen atoms. Examples of other substituents include a trifluoromethyl group, an aryl group having 6 to 12 carbon atoms, an alkoxy group having 1 to 12 carbon atoms, and an aryloxy group having 6 to 12 carbon atoms. Examples of the alkyl group constituting these substituents include the groups described above, and examples of the aryl group include groups described below.
The ^{R 1, R 2, R 5} , R 6, an aryl group having 6 to 12 carbon atoms constituting the R ^7, a phenyl group.
Examples of the alkyl group and aryl group constituting the alkoxy group having 1 to 12 carbon atoms constituting R ¹ and R ² and the aryloxy group having 6 to 12 carbon atoms include the aforementioned groups.
In said group, when an aryl group or an aryloxy group has a substituent, a C1-C6 alkyl group can be mentioned as a substituent. The alkyl group having 1 to 6 carbon atoms include the groups exemplified in the description of the above R ^1, R ^2. Examples of other substituents include a halogen atom and a trifluoromethyl group.
R ¹ , R ² , R ⁵ , R ⁶ and R ⁷ may all be hydrogen atoms, and when there are a plurality of groups other than hydrogen atoms, they may be the same as or different from each other. Good.

Examples of the substituted or unsubstituted cycloalkylidene group having 5 to 20 carbon atoms constituting X include cycloalkylidene groups derived from cyclopentane, cyclohexane, cycloheptane, cyclooctane, cyclononane, and cyclodecane. Furthermore, a cycloalkylidene group derived from adamantane, chilicyclodecane, dicyclopentadiene or norbornene can be mentioned. Moreover, as a substituent added to a cycloalkylidene group, a C1-C6 alkyl group can be mentioned. The alkyl group having 1 to 6 carbon atoms include the groups exemplified in the description of the above R ^1, R ^2. The number of substituents to be added is not limited to 1, and a mode in which a plurality of different substituents are added can also be adopted. Examples of the substituted or unsubstituted bicyclo or tricyclohydrocarbon diyl group having 5 to 20 carbon atoms constituting X include a group derived from adamantane. Examples of the substituent added to the bicyclo or tricyclohydrocarbon diyl group include the same groups as the substituents added to the aforementioned cycloalkylidene group.

Ar ² is a divalent group derived from substituted or unsubstituted biphenol, dihydroxynaphthalene, hydroquinone, resorcin, catechol, 9,9-bis (hydroxyphenyl) fluorene, or 4,4′-dihydroxydiphenylmethane. .
When Ar ² is a biphenol derivative, it is preferable to bond to oxygen at the 4,4 ′ position from the viewpoint of improving mechanical properties and wear resistance. In the case of a naphthalene derivative, it can take an embodiment in which it binds to an oxygen atom at any of positions 1 to 8, but it can bind at positions 2, 7, 2, 6, 1, 4, or 1, 5 This is preferable in terms of improving mechanical properties and wear resistance. The other substituent and the bonding position with the oxygen atom are the same as Ar ¹ .

In the present invention, it is preferable that Ar ² further contains a divalent organosiloxane-modified phenylene group.
The divalent organosiloxane-modified phenylene group is, for example, a group represented by the following formula (2A).

(In Formula (2A), R ²¹ and R ²² each independently represent a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or a carbon number of 6 to 6). 12 substituted or unsubstituted aryl groups are shown.
As the halogen atom, a chlorine atom is preferable. Examples of the substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, the substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or the substituted or unsubstituted aryl group having 6 to 12 carbon atoms include R ¹ and R ² Examples include the groups shown in the description.
R ²¹ and R ²² are preferably a hydrogen atom or an alkoxy group having 1 to 3 carbon atoms, and more preferably a specific structure described later.
R ²³ is a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
Examples of the substituted or unsubstituted alkyl group having 1 to 12 carbon atoms and the substituted or unsubstituted aryl group having 6 to 12 carbon atoms include the groups described in the description of R ¹ and R ² . Preferably, they are a phenyl group and a methyl group.
n1 is an integer of 2 to 4, and n2 is an integer of 1 to 600. )

  In addition, the divalent organosiloxane-modified phenylene group may be a group represented by the formula (2B).

(In formula (2B), each R ³¹ is independently a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or a 6 to 12 carbon number. The halogen atom which is a substituted or unsubstituted aryl group is preferably a chlorine atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or 6 carbon atoms. Examples of the substituted or unsubstituted aryl group of ˜12 include the groups described in the description of R ¹ and R ² .
R ³² is each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
Examples of the substituted or unsubstituted alkyl group having 1 to 12 carbon atoms and the substituted or unsubstituted aryl group having 6 to 12 carbon atoms include the groups described in the description of R ¹ and R ² . Preferably, they are a phenyl group and a methyl group.
R ³³ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond.
Examples of the monovalent hydrocarbon group include substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms and substituted or unsubstituted aryl groups having 6 to 12 carbon atoms. Among these, an alkyl group having 1 to 12 carbon atoms is preferable, and a methyl group is particularly preferable.
R ³⁴ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond.
Examples of the monovalent hydrocarbon group include substituted or unsubstituted alkyl groups having 1 to 12 carbon atoms and substituted or unsubstituted aryl groups having 6 to 12 carbon atoms. Among these, an alkyl group having 1 to 12 carbon atoms is preferable, and a methyl group is particularly preferable.
Y and Y ′ are an alkylene group having 2 or more carbon atoms, an alkyleneoxyalkylene, or an oxygen atom. The alkylene group is preferably an alkylene group having 2 to 10 carbon atoms, and more preferably a methylene group having 2 to 4 repeating units.
na is 0 or 1, nb is 1 or 2, and nc is 1 or 2. However, na + nb + nc is 3.
n1 to n4 are each an integer of 0 or more, the sum of n1, n2, n3, and n4 is an integer of 2 to 600, and the sum of n3 and n4 is an integer of 1 or more.
a is 0 or an integer from 1 to 4. Preferably, a is 0 or 1. )

By further including a divalent organosiloxane-modified phenylene group as Ar ² , the electrophotographic photosensitive member using the PC copolymer as a binder resin can reduce the surface energy and reduce the adhesion of foreign matters. Specifically, it is possible to prevent foreign matters such as toner from adhering to the electrophotographic photosensitive member.
Specific examples of such a divalent organosiloxane-modified phenylene group include the following.

In the above formula, the number of repeating units (n) of the organic siloxyxylene group is preferably 1 or more and 600 or less, more preferably 10 or more and 300 or less, particularly preferably 20 or more and 200 or less, and most preferably 30 or more and 150 or less.
By setting n to 600 or less, compatibility with the PC copolymer is improved, and the reaction can be completed in the polymerization step. Therefore, since the unreacted organosiloxane-modified phenolic compound can be prevented from remaining in the final PC copolymer, the residual potential increases when applied as a binder resin for an electrophotographic photoreceptor without causing the resin to become cloudy. Can be suppressed.
On the other hand, when n is 1 or more, the surface energy property can be sufficiently imparted to the electrophotographic photosensitive member, and adhesion of foreign matters can be satisfactorily prevented.
The proportion of the divalent organosiloxane-modified phenylene group in the PC copolymer is 0.01% by mass to 50% by mass, preferably 0.1% by mass to 20% by mass, and more preferably 0.5% by mass. It is 10 mass% or less, Most preferably, it is 1 mass% or more and 6 mass% or less.
By making the said ratio 0.1 mass% or more, adhesion of a foreign material can be prevented further favorably. On the other hand, when the ratio is 50% by mass or less, it can be suitably used for an electrophotographic photoreceptor having excellent abrasion resistance and sufficient mechanical strength.

In the PC copolymer of the present invention, the reduced viscosity [η _SP / C] at 20 ° C. of a 0.5 g / dl solution containing methylene chloride as a solvent is 0.1 dl / g or more and 5 dl / g or less. Is more preferably 0.2 dl / g or more and 3 dl / g or less, particularly preferably 0.3 dl / g or more and 2.5 dl / g or less. When the reduced viscosity [η _SP / C] is less than 0.1 dl / g, when used as an electrophotographic photosensitive member, its wear resistance may be insufficient. On the other hand, when the reduced viscosity [η _SP / C] exceeds 5 dl / g, when a molded product such as an electrophotographic photosensitive member is produced from a coating solution, the coating viscosity becomes too high, and the electrophotographic photosensitive member or the like. This is not preferable because the productivity of the molded article may be reduced.

  In the present invention, the PC copolymer described in the formula (1) is a polycarbonate copolymer in which the chain end is sealed with a monovalent aromatic group or a monovalent fluorine-containing aliphatic group. From the viewpoint of improving the electrical characteristics.

In the PC copolymer having improved electrical properties, the terminal group is a monovalent aromatic group or a monovalent fluorine-containing aliphatic group. The monovalent aromatic group may be a group containing an aliphatic group such as an alkyl group. The monovalent fluorine-containing aliphatic group may be a group containing an aromatic group.
The monovalent aromatic group constituting the terminal group is preferably an aryl group having 6 to 12 carbon atoms. Examples of such an aryl group include a phenyl group and a biphenyl group. Examples of the substituent added to an aliphatic group such as an aromatic group or an alkyl group added to the aromatic group include halogen atoms such as a fluorine atom, a chlorine atom, and a bromine atom. Moreover, a C1-C20 alkyl group is mentioned as a substituent added to an aromatic group. The alkyl group may be a group to which a halogen atom is added as described above, or may be a group to which an aryl group is added.
Examples of the monovalent fluorine-containing aliphatic group constituting the terminal group include a fluorine-containing alkyl group having 1 to 20 carbon atoms.

When the chain terminal is a monovalent aromatic group, it may be an organosiloxane-modified phenyl group.
The monovalent organosiloxane-modified phenyl group is, for example, a group represented by the following formula (2C).

(Z is a hydrocarbon group having 2 to 6 carbon atoms, preferably an alkylene group, and more preferably a methylene group having 2 to 4 repeating units.
R ⁴¹ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms. Preferably it is a C1-C6 alkyl group.
R ^{42 to} R ⁴⁵ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted group having 6 to 12 carbon atoms. An aryl group. Examples of the substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, the substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or the substituted or unsubstituted aryl group having 6 to 12 carbon atoms include R ¹ and R ² Examples include the groups shown in the description.
R ^{46 to} R ⁴⁹ are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms and a substituted or unsubstituted aryl group having 6 to 12 carbon atoms. Examples of the substituted or unsubstituted alkyl group having 1 to 12 carbon atoms and the substituted or unsubstituted aryl group having 6 to 12 carbon atoms include the groups described in the description of R ¹ and R ² . Preferably, they are a phenyl group and a methyl group.
n is an integer of 2 to 600, and indicates the average number of repeating units when it has a molecular weight distribution. )

  Examples of such monovalent organosiloxane-modified phenyl groups include the following.

In an electrophotographic photoreceptor using a PC copolymer having a monovalent organosiloxane-modified phenyl group as a binder resin, it is possible to reduce adhesion of foreign matters such as toner.
The ratio of the monovalent organosiloxane-modified phenyl group necessary for exhibiting the above effect is 0.01% by mass or more and 50% by mass or less with respect to the entire PC copolymer. More preferably, they are 0.1 mass% or more and 20 mass% or less, Most preferably, they are 0.5 mass% or more and 10 mass% or less.
In addition to the monovalent organosiloxane-modified phenyl group, in a PC copolymer in which a unit derived from a divalent organosiloxane-modified phenylene group is contained in the main chain, these units are added together.

[Method for producing PC copolymer]
The PC copolymer of the present invention uses, for example, a low-molecular-weight bischloroformate oligomer represented by the following formula (4), and a dihydric phenolic compound represented by the following formula (5) in the presence of a base. It is obtained by reacting with By using such an oligomer, a PC copolymer having an Ar ¹ block average repeating number in the range of 1.09 to 3.0 can be produced.

Here, n ′ indicating the average number of bischloroformate oligomers is different from n in the formula (1). n and n ′ have the same value, but the value of n is larger. It after forming the Ar ¹ oligomer, upon reaction with monomers containing Ar ^2, chloroformate group of Ar ¹ oligomer end, react with a base present in the reaction system becomes a hydroxyl group, this is a chlorine-terminated This is because polycondensation with the Ar ¹ block may occur.
In the bischloroformate oligomer of the formula (4), the average monomer number n ′ is in the range of 1.0 or more and 1.99 or less. By using a bischloroformate oligomer having an average number of monomers in the range of 1.0 or more and 1.99 or less, the production of the PC copolymer of the present invention is facilitated. Examples of a method for calculating the average number n of monomers include methods described later in Examples.

Furthermore, in the present invention, Ar ¹ represented by the formula (2) is 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1- Bis (4-hydroxyphenyl) cyclododecane, 2,2-bis (4-hydroxyphenyl) adamantane, 1,3-bis (4-hydroxyphenyl) adamantane, 1,1-bis (4-hydroxyphenyl) -3, 3,5-trimethylcyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclopentane, or the above formula (3) A divalent group derived from a group selected from the above groups is preferable from the viewpoint of improving the solubility in an organic solvent.

Note that the raw material containing the bischloroformate oligomer represented by Formula (4) may contain an amide compound as an impurity. The content of the amide compound (the mass of nitrogen derived from the amide compound) is determined based on the mass of nitrogen atoms contained in the raw material containing the bischloroformate oligomer. The content of the amide compound is 700 mass ppm or less, preferably 400 mass ppm or less, more preferably 400 mass ppm or less, based on the total mass of the raw material containing the bischloroformate oligomer when the solvent is removed from the solution containing the raw material to form a solid. Is 150 ppm by mass or less, particularly preferably 80 ppm by mass or less, and most preferably 20 ppm by mass or less.
By making content of an amide compound 700 mass ppm or less, when a PC copolymer is applied as a binder resin of an electrophotographic photosensitive member, it can suppress that a residual potential raises. The bischloroformate oligomer is not limited to a solid substance but may be a liquid.

Examples of the amide compound include N, N, N ′, N′-tetraalkylurea, N, N-dialkylcarbamic acid chloride such as N, N-diethylcarbamic acid chloride, N, N-dialkylcarbamic acid, bisphenol-monochlorophore. Examples thereof include polymers of mate-monoalkyl carbamate and bisphenol-bisdialkyl carbamate.
When producing a bischloroformate oligomer, if an amine compound such as triethylamine is used in a large amount, the amine compound and the bischloroformate compound may react to produce an amide compound as an impurity.
However, the content of the amide compound can be reduced as described above by increasing the number of times the bischloroformate oligomer is washed.
Examples of reducing means other than washing with water include distillation, use of an adsorbent, and column fractionation.

And the PC copolymer obtained using the said bischloroformate oligomer may also contain dialkyl carbamic-acid chlorides, such as diethyl carbamic-acid chloride, as an impurity. In this case, the content of dialkylcarbamic acid chloride is 100 mass ppm or less, preferably 50 mass ppm or less, more preferably 40 mass ppm or less, based on the total mass of the PC copolymer.
By setting the content of dialkylcarbamic acid chloride to 100 mass ppm or less, an increase in the residual potential is suppressed, and an electrophotographic photosensitive member having good sensitivity can be obtained.

As the method for producing the PC copolymer of the present invention, for example, a bischloroformate oligomer derived from a dihydric phenol compound represented by the following formula (6) and a biphenol, dihydroxy represented by the following formula (7): Examples thereof include a polycondensation method with a dihydric phenol compound derived from naphthalene, hydroquinone, resorcin, catechol, 9,9-bis (hydroxyphenyl) fluorene, or 4,4′-dihydroxydiphenylmethane.
HO—Ar ¹ —OH (6)
HO—Ar ² —OH (7)

  Examples of the monomer represented by the above formula (6) include 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclopentane, and 1,1. -Bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis (4-hydroxyphenyl) adamantane, 2,2-bis ( 3-methyl-4-hydroxyphenyl) adamantane, 1,3-bis (4-hydroxyphenyl) adamantane, 1,3-bis (3-methyl-4-hydroxyphenyl) adamantane, 1,1-bis (3-methyl) -4-hydroxyphenyl) cyclohexane, 1,1-bis (3-cyclohexyl-4-hydroxyphenyl) cyclo Xanthone, 1,1-bis (3-phenyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) cycloheptane, 1,1-bis (3-methyl-4-hydroxyphenyl) cycloheptane 1,1-bis (4-hydroxyphenyl) cyclooctane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclooctane, 1,1-bis (4-hydroxyphenyl) cyclononane, 1,1- Bis (3-methyl-4-hydroxyphenyl) cyclononane, 1,1-bis (4-hydroxyphenyl) cyclodecane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclodecane, 1,1-bis (4 -Hydroxyphenyl) cycloundecane, 1,1-bis (3-methyl-4-hydroxyphenyl) cycloun Kang, 1,1-bis (4-hydroxyphenyl) cyclododecane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclododecane, further include compounds represented by the following formula.

  Among them, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1 -Bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane, 2,2-bis (4-hydroxyphenyl) adamantane, 2,2-bis (3-methyl-4-hydroxyphenyl) adamantane, 3-bis (4-hydroxyphenyl) adamantane, 1,3-bis (3-methyl-4-hydroxyphenyl) adamantane, 1,1-bis (3-methyl-4-hydroxyphenyl) cyclohexane, 1,1-bis (4-Hydroxyphenyl) cyclododecane, 1,1-bis (3-methyl-4-hydroxyphenyl) cycl Preferable in terms of providing PC copolymer dodecane excellent solubility.

Particularly preferably, 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl) cyclododecane, 2,2-bis (4-hydroxyphenyl) adamantane, 1,3-bis (4-hydroxyphenyl) adamantane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane.
Moreover, when it applies as a PC copolymer for electrophotographic photoreceptors, it is preferable because a good coating solution can be obtained. These may be used alone or in combination of two or more.

Next, the monomer represented by the formula (7) will be described. From the viewpoint of wear resistance, the monomer that is a raw material for Ar ² , which is another constituent unit of the PC copolymer of the present invention, has a solubility in the homopolymer of methylene chloride of 2% by mass or less, or an interface. It is a biphenol or bisphenol monomer in which synthesis of a homopolymer having a number average molecular weight of 10,000 or more is substantially impossible due to crystallization of a copolymer produced during a polycarbonate synthesis reaction by a polycondensation method.
Whether or not the solubility in methylene chloride is 2% by mass or less is determined based on whether the organic solvent content is 500 ppm by mass or less and the viscosity average molecular weight is in the range of 15000 or more and 30000 or less, 2 parts by mass of a solid homopolymer. Is immersed in 98 parts by mass of methylene chloride at room temperature and allowed to stand for 24 hours, followed by solid-liquid separation and drying of the solid side to confirm whether or not the mass reduction is 0.04 parts by mass or more.

Such monomers include 4,4′-biphenol, 3,3′-dimethyl-4,4′-biphenol, 3,3 ′, 5-trimethyl-4,4′-biphenol, 3-propyl-4, 4'-biphenol, 3,3 ', 5,5'-tetramethyl-4,4'-biphenol, 3,3'-diphenyl-4,4'-biphenol, 3,3'-dibutyl-4,4' -Biphenol compounds such as biphenol, hydroquinone, resorcin, 2,7-naphthalenediol, 2,6-naphthalenediol, 1,4-naphthalenediol, 1,5-naphthalenediol, 9,9-bis (3-phenyl-4 -Hydroxyphenyl) fluorene, 9,9-bis (4-hydroxyphenyl) fluorene, 9,9-bis (3-methyl-4-hydroxyphenyl) fluorene, bis (4-hydro) Xylphenyl) methane, bis (3-methyl-4-hydroxyphenyl) methane, and the like. These bisphenol compounds may be used alone or in combination of two or more.
Among these, 4,4′-biphenol, hydroquinone, resorcin, 2,7-naphthalenediol, 9,9-bis (3-methyl-4-hydroxyphenyl) fluorene, and bis (3-methyl-4-hydroxyphenyl) methane are resistant. This is preferable because a resin having excellent wear characteristics can be obtained.

The PC copolymer of the present invention can also be obtained by further polymerizing the monomer represented by the formula (7) in which Ar ² is a divalent organosiloxane-modified phenylene group. In this case, examples of the divalent organosiloxane-modified phenylene group include those described above.

The PC copolymer of the present invention can be obtained by interfacial polycondensation using a bischloroformate oligomer obtained from a monomer of formula (6) and a monomer of formula (7). For example, a carbonate ester bond can be suitably formed by performing interfacial polycondensation in the presence of an acid binder using various dihalogenated carbonyls including phosgene. These reactions are performed in the presence of a terminal terminator and / or a branching agent as necessary. In the production of the PC copolymer of the present invention, two or more kinds of Ar ² derived monomers may be used to form a multi-component copolymer.

As a terminal terminator for generating a chain end, a monovalent carboxylic acid and a derivative thereof, or a monovalent phenol can be used. For example, p-tert-butyl-phenol, p-phenylphenol, p-cumylphenol, p-perfluorononylphenol, p- (perfluorononylphenyl) phenol, p- (perfluorohexyl) phenol, p-tert- Perfluorobutylphenol, perfluorooctylphenol, perfluorohexylphenol, 1- (p-hydroxybenzyl) perfluorodecane, p- [2- (1H, 1H-perfluorotridodecyloxy) -1,1,1,3 3,3-hexafluoropropyl] phenol, 3,5-bis (perfluorohexyloxycarbonyl) phenol, perfluorododecyl p-hydroxybenzoate, p- (1H, 1H-perfluorooctyloxy) phenol, 2H, 2H , 9H Perfluoro nonanoic acid, 1,1,1,3,3,3 Tetorafuroro-2-propanol or, alcohols represented by the following formula (8) and (9) is preferably used.
H (CF ₂ ) _n CH ₂ OH (8)
(N is an integer from 1 to 12)
F (CF ₂ ) _m CH ₂ OH (9)
(M is an integer from 1 to 12)

  In addition, as the monovalent phenol, a compound in which the above-described monovalent organosiloxane-modified phenyl group is a monovalent phenol can also be suitably used.

  The addition ratio of these end stoppers is 0.05 mol% or more and 30 mol% or less, more preferably 0.1 mol% or more and 10 mol% or less as a copolymer composition ratio, and this ratio exceeds 30 mol%. If the amount is less than 0.05 mol%, the moldability may be lowered.

Specific examples of the branching agent include phloroglucin, pyrogallol, 4,6-dimethyl-2,4,6-tris (4-hydroxyphenyl) -2-heptene, 2,6-dimethyl-2,4,6- Tris (4-hydroxyphenyl) -3-heptene, 2,4-dimethyl-2,4,6-tris (4-hydroxyphenyl) heptane, 1,3,5-tris (2-hydroxyphenyl) benzene, 1, 3,5-tris (4-hydroxyphenyl) benzene, 1,1,1-tris (4-hydroxyphenyl) ethane, tris (4-hydroxyphenyl) phenylmethane, 2,2-bis [4,4-bis ( 4-hydroxyphenyl) cyclohexyl] propane, 2,4-bis [2-bis (4-hydroxyphenyl) -2-propyl] phenol, 2,6-bis (2 Hydroxy-5-methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2- (2,4-dihydroxyphenyl) propane, tetrakis (4-hydroxyphenyl) methane, tetrakis [4- (4- Hydroxyphenylisopropyl) phenoxy] methane, 2,4-dihydroxybenzoic acid, trimesic acid, cyanuric acid, 3,3-bis (3-methyl-4-hydroxyphenyl) -2-oxo-2,3-dihydroindole, 3 , 3-bis (4-hydroxyaryl) oxindole, 5-chloroisatin, 5,7-dichloroisatin, 5-bromoisatin and the like.
The addition amount of these branching agents is 30 mol% or less, preferably 5 mol% or less in terms of the copolymer composition ratio, and if this exceeds 30 mol%, moldability may be deteriorated.

  When performing interfacial polycondensation, examples of the acid binder include alkali metal hydroxides such as sodium hydroxide, potassium hydroxide, lithium hydroxide, and cesium hydroxide, and alkaline earths such as magnesium hydroxide and calcium hydroxide. Organic bases such as metal hydroxide, sodium carbonate, potassium carbonate, calcium acetate and other alkali metal weak acid salts, alkaline earth metal weak acid salts, and pyridine are preferred, but sodium hydroxide, potassium hydroxide, calcium hydroxide are preferred. Alkali metal hydroxides and alkaline earth metal hydroxides. These acid binders can also be used as a mixture. What is necessary is just to adjust the usage-amount of an acid binder suitably considering the stoichiometric ratio (equivalent) of reaction. Specifically, 1 equivalent or an excess amount, preferably 1 equivalent or more and 10 equivalents or less of an acid binder may be used per 1 mol of the total of hydroxyl groups of the dihydric phenol as a raw material.

  As the solvent used here, there is no problem as long as it shows a certain solubility or more with respect to the obtained PC copolymer. For example, aromatic hydrocarbons such as toluene and xylene, methylene chloride, chloroform, 1,1-dichloroethane, 1,2-dichloroethane, 1,1,1-trichloroethane, 1,1,2-trichloroethane, 1,1,1 , 2-tetrachloroethane, 1,1,2,2-tetrachloroethane, halogenated hydrocarbons such as pentachloroethane, chlorobenzene, ketones such as cyclohexanone, acetone, acetophenone, ethers such as tetrahydrofuran, 1,4-dioxane, etc. Are mentioned as preferred. These solvents may be used alone or in combination of two or more. Further, the interfacial polycondensation reaction may be performed using two kinds of solvents that are not mixed with each other.

Catalysts include trimethylamine, triethylamine, tributylamine, N, N-dimethylcyclohexylamine, pyridine, tertiary amines such as N, N-diethylaniline, N, N-dimethylaniline, trimethylbenzylammonium chloride, triethyl Quaternary ammonium salts such as benzylammonium chloride, tributylbenzylammonium chloride, trioctylmethylammonium chloride, tetrabutylammonium chloride and tetrabutylammonium bromide, and quaternary phosphonium salts such as tetrabutylphosphonium chloride and tetrabutylphosphonium bromide are suitable. is there.
Furthermore, you may add small amounts of antioxidants, such as sodium sulfite and a hydrosulfite salt, to this reaction system as needed.

The method for producing the PC copolymer of the present invention can be specifically carried out in various modes. For example, the bisphenolformate oligomer can be produced by reacting the bisphenol compound of the formula (6) with phosgene. Adopting a method of producing a low-mer number product and then reacting the bischloroformate oligomer with the formula (7) in the presence of a mixture of the solvent and an alkaline aqueous solution of an acid binder, It is preferable at the point which can adjust n value in the said Formula (1) to a preferable range.
As a method for producing this bischloroformate oligomer, it is preferable to use one produced by the following method from the viewpoint that the washing step at the time of producing the polycarbonate copolymer can be simplified.

As a manufacturing method of the bischloroformate oligomer in which n 'value of Formula (4) is in the range of 1.0 or more and 1.99 or less, there is a method shown in a manufacturing example described later. First, the bisphenol compound of the formula (6) is suspended in a hydrophobic solvent such as methylene chloride, and phosgene is added to form a mixed solution. On the other hand, a tertiary amine such as triethylamine is dissolved in a hydrophobic solvent such as methylene chloride to form a solution, and this solution is dropped into the mixed solution and reacted at a temperature of room temperature or lower. Hydrochloric acid and pure water are added to the residual liquid of the obtained reaction mixture and washed to obtain an organic layer containing a low-molecular-weight polycarbonate oligomer.
The dropping temperature and reaction temperature are usually 0 to 70 ° C., preferably 5 to 65 ° C., and both the dropping time and reaction time are about 15 minutes to 4 hours, preferably about 30 minutes to 3 hours. The average number of oligomers (n ′) of the polycarbonate oligomer thus obtained is preferably from 1.00 to 1.99, more preferably from 1.00 to 1.60.

A dihydric phenol monomer having a different skeleton represented by the formula (7) is added to the organic phase containing the bischloroformate oligomer having a low number of monomers obtained in this manner, and reacted. The reaction temperature is 0 to 150 ° C, preferably 5 to 40 ° C, particularly preferably 10 to 25 ° C.
The reaction pressure may be any of reduced pressure, normal pressure, and increased pressure. Usually, it can be suitably carried out at normal pressure or about the pressure of the reaction system. The reaction time depends on the reaction temperature, but is usually 0.5 minutes to 10 hours, preferably about 1 minute to 2 hours.

  In this reaction, the dihydric phenol monomer represented by the formula (7) is preferably added as an aqueous solution or an organic solvent solution. There is no restriction | limiting in particular about the addition order. In addition, a catalyst, a terminal terminator, a branching agent, and the like are added in the above production method, if necessary, either during the production of the bischloroformate oligomer, during the subsequent high molecular weight reaction, or both. Can be used.

The PC copolymer thus obtained is a copolymer comprising a repeating unit represented by the following formula (10) and a repeating unit represented by the formula (11).
In addition, the PC copolymer contains a polycarbonate unit having a structural unit other than Ar ¹ and Ar ² , a unit having a polyester, or a polyether structure, as long as the achievement of the object of the present invention is not hindered. It may be.

In order to bring the reduced viscosity [η _sp / C] of the obtained PC copolymer into the above range, for example, by selection of the reaction conditions, adjustment of the amount of branching agent or terminal terminator used, and the like. Can be made. In some cases, the obtained PC copolymer is appropriately subjected to physical treatment (mixing, fractionation, etc.) and / or chemical treatment (polymer reaction, crosslinking treatment, partial decomposition treatment, etc.) to give a predetermined reduced viscosity [ η _sp / C] can also be obtained as a PC copolymer.
Moreover, the obtained reaction product (crude product) can be subjected to various post-treatments such as a known separation and purification method, and a product having a desired purity (purity) can be recovered as a PC copolymer. .

[Composition of coating liquid]
The coating liquid of the present invention comprises at least the PC copolymer of the present invention and a solvent capable of dissolving or dispersing the present PC copolymer. In addition to the above, the coating liquid may be a low molecular compound, a colorant such as a dye or a pigment, a charge transport material, an electron transport material, a hole transport material, a functional compound such as a charge generation material, an inorganic or organic filler, Additives such as fibers, fillers such as fine particles, antioxidants, ultraviolet absorbers, and acid scavengers may be included. Examples of the substance that may be contained other than the resin include those contained in the constituent components of the electrophotographic photoreceptor described later. Further, the coating solution may contain other resins as long as the effects of the present invention are not impaired, and examples thereof are given as examples of the constituent components of the following electrophotographic photoreceptor. In addition, the solvent used in the present invention is considered alone or in consideration of the solubility, dispersibility, viscosity, evaporation rate, chemical stability, stability against physical changes of the present PC copolymer and other materials. A plurality of solvents can be mixed and used. The example is mentioned as an example of the component of the electrophotographic photoreceptor described later.

The concentration of the copolymer component in the present coating solution may be an appropriate viscosity according to the usage method of the coating solution, but is preferably 0.1% by mass or more and 40% by mass or less. More preferably, it is more preferably from 35% by mass to 35% by mass, and most preferably from 5% by mass to 30% by mass. When it exceeds 40 mass%, since viscosity is too high, coating property will deteriorate. If it is less than 0.1% by mass, the coating liquid flows because the viscosity is too low, a homogeneous film cannot be obtained, or the concentration is too low, so it takes a long time to dry after coating, The film thickness may not be reached.

The PC copolymer of the present invention has good compatibility with the charge transport material, and does not cause whitening or gelation even when dissolved in the solvent. Therefore, the coating liquid of the present invention containing the copolymer, the charge transport material and the solvent can be stored stably over a long period of time. Further, when a photosensitive layer of an electrophotographic photosensitive member is formed using this coating solution, an excellent electrophotographic photosensitive member that does not cause crystallization of the photosensitive layer and does not cause image quality defects can be produced. .
The ratio of the PC copolymer and the charge transport material in the coating solution is usually 20:80 to 80:20, preferably 30:70 to 70:30 in terms of mass ratio.
In the coating liquid of the present invention, the PC copolymer of the present invention may be used alone or in combination of two or more.

  The coating solution of the present invention is generally suitably used for forming a charge transport layer of a multilayer electrophotographic photoreceptor in which the photosensitive layer includes at least a charge generation layer and a charge transport layer. Further, the coating solution can be used for forming a photosensitive layer of a single layer type electrophotographic photosensitive member by further containing the charge generating substance.

[Configuration of electrophotographic photoreceptor]
The electrophotographic photosensitive member of the present invention may be any known various types of electrophotographic photosensitive members as long as the above-mentioned PC copolymer is used in the photosensitive layer. It is preferable to use a laminated organic electrophotographic photoreceptor having one charge generation layer and at least one charge transport layer, or a single layer organic electrophotographic photoreceptor having a charge generation material and a charge transport material in one layer. .

The PC copolymer may be used in any part of the photosensitive layer, but in order to fully exhibit the effects of the present invention, it is used as a binder resin for a charge transfer material in the charge transport layer, It is desirable to use it as a binder resin for a single photosensitive layer or as a surface protective layer. In the case of a multilayer electrophotographic photosensitive member having two charge transport layers, it is preferably used for any one of the charge transport layers.
In the electrophotographic photoreceptor of the present invention, the above-described PC copolymer of the present invention may be used alone or in combination of two or more. Moreover, you may contain binder resin components, such as another polycarbonate, in the range which does not inhibit the objective of this invention as desired. Furthermore, you may contain additives, such as antioxidant.

  The electrophotographic photoreceptor of the present invention has a photosensitive layer on a conductive substrate. When the photosensitive layer has a charge generation layer and a charge transport layer, the charge transport layer may be laminated on the charge generation layer, or the charge generation layer may be laminated on the charge transport layer. Further, the charge generation material and the charge transport material may be included in one layer at the same time. Furthermore, a conductive or insulating protective film may be formed on the surface layer as necessary. Further, an adhesive layer for improving the adhesion between the layers or an intermediate layer such as a blocking layer that serves to block charges may be formed.

  As the conductive substrate material used for the electrophotographic photoreceptor of the present invention, various materials such as known ones can be used. Specifically, aluminum, nickel, chromium, palladium, titanium, molybdenum, indium, Plates, drums and sheets made of gold, platinum, silver, copper, zinc, brass, stainless steel, lead oxide, tin oxide, indium oxide, ITO (indium tin oxide: tin-doped indium oxide) or graphite, and vapor deposition, sputtering, Glass, cloth, paper or plastic film, sheet and seamless belt subjected to conductive treatment by coating or the like, and metal drum subjected to metal oxidation treatment by electrode oxidation or the like can be used.

  The charge generation layer has at least a charge generation material, and the charge generation layer is formed by forming a layer of the charge generation material on the underlying substrate by vacuum deposition, sputtering, or the like, or the underlying substrate It can be obtained by forming a layer on which a charge generating material is bound using a binder resin. Various methods such as a known method can be used as a method for forming a charge generation layer using a binder resin. Usually, for example, a coating solution in which a charge generation material is dispersed or dissolved in a suitable solvent together with a binder resin is used. A method of obtaining a wet molded body by applying on a substrate as a predetermined base and drying it is preferable.

Various known materials can be used as the charge generation material in the charge generation layer. Specific compounds include amorphous selenium, selenium alone such as trigonal selenium, selenium alloys such as selenium-tellurium, selenium compounds such as As ₂ Se ₃ or selenium-containing compositions, zinc oxide, CdS-Se, etc. Inorganic materials comprising Group 12 and Group 16 elements of the periodic table, oxide-based semiconductors such as titanium oxide, silicon-based materials such as amorphous silicon, metal-free phthalocyanines such as τ-type metal-free phthalocyanine and χ-type metal-free phthalocyanine Pigment, α-type copper phthalocyanine, β-type copper phthalocyanine, γ-type copper phthalocyanine, ε-type copper phthalocyanine, X-type copper phthalocyanine, A-type titanyl phthalocyanine, B-type titanyl phthalocyanine, C-type titanyl phthalocyanine, D-type titanyl phthalocyanine, E-type titanyl Phthalocyanine, F-type titanyl phthalocyanine, G-type titanyl Talocyanine, H-type titanyl phthalocyanine, K-type titanyl phthalocyanine, L-type titanyl phthalocyanine, M-type titanyl phthalocyanine, N-type titanyl phthalocyanine, Y-type titanyl phthalocyanine, oxo titanyl phthalocyanine, black angle 2θ in X-ray diffraction diagram is 27.3 ± 0 .Metallic phthalocyanine pigments such as titanyl phthalocyanine and gallium phthalocyanine showing strong diffraction peaks twice, cyanine dyes, anthracene pigments, bisazo pigments, pyrene pigments, polycyclic quinone pigments, quinacridone pigments, indigo pigments, perylene pigments, pyrylium dyes, squalium Pigment, Antanthrone pigment, benzimidazole pigment, azo pigment, thioindigo pigment, quinoline pigment, lake pigment, oxazine pigment, dioxazine pigment, triphenylmethane Fee, azulenium dyes, triarylmethane dyes, xanthine dyes, thiazine dyes, thiapyrylium dyes, polyvinylcarbazole, and the like bisbenzimidazole pigments. These compounds can be used alone as a charge generation material, or a mixture of two or more. Among these charge generating materials, preferred are those specifically described in JP-A-11-172003.

The charge transport layer can be obtained as a wet molded body by forming a layer formed by binding a charge transport material with a binder resin on a base substrate. There is no restriction | limiting in particular as binder resin of an above described electric charge generation layer or an electric charge transport layer, A well-known various thing can be used. Specifically, polystyrene, polyvinyl chloride, polyvinyl acetate, vinyl chloride-vinyl acetate copolymer, polyvinyl acetal, alkyd resin, acrylic resin, polyacrylonitrile, polycarbonate, polyurethane, epoxy resin, phenol resin, polyamide, polyketone, Polyacrylamide, butyral resin, polyester resin, vinylidene chloride-vinyl chloride copolymer, methacrylic resin, styrene-butadiene copolymer, vinylidene chloride-acrylonitrile copolymer, vinyl chloride-vinyl acetate-maleic anhydride copolymer, silicone Resin, silicone-alkyd resin, phenol-formaldehyde resin, styrene-alkyd resin, melamine resin, polyether resin, benzoguanamine resin, epoxy acrylate resin, urea Acrylate resin, poly-N-vinyl carbazole, polyvinyl butyral, polyvinyl formal, polysulfone, casein, gelatin, polyvinyl alcohol, ethyl cellulose, nitrocellulose, carboxy-methyl cellulose, vinylidene chloride polymer latex, acrylonitrile-butadiene copolymer, vinyl toluene- Examples include styrene copolymers, soybean oil-modified alkyd resins, nitrated polystyrene, polymethylstyrene, polyisoprene, polythiocarbonate, polyarylate, polyhaloarylate, polyallyl ether, polyvinyl acrylate, and polyester acrylate.
These can also be used individually by 1 type and can also be used in mixture of 2 or more types. As the binder resin in the charge generation layer and the charge transport layer, it is preferable to use the above-described PC copolymer of the present invention.

As a method for forming the charge transport layer, various known methods can be used. A coating solution in which a charge transport material is dispersed or dissolved in a suitable solvent together with the PC copolymer of the present invention is used as a predetermined base. The method of apply | coating on the board | substrate used as this, and drying and obtaining as a wet molded object is suitable. The blending ratio of the charge transport material used for forming the charge transport layer and the PC copolymer is preferably 20:80 to 80:20, more preferably 30:70 to 70:30 in terms of mass ratio.
In this charge transport layer, the PC copolymer of the present invention can be used singly or in combination of two or more. In addition, other binder resins can be used in combination with the PC copolymer of the present invention as long as the object of the present invention is not impaired.

The thickness of the charge transport layer thus formed is usually about 5 μm to 100 μm, preferably 10 μm to 30 μm. If the thickness is less than 5 μm, the initial potential may be lowered, and if it exceeds 100 μm, the electrophotographic characteristics may be deteriorated.
Various known compounds can be used as the charge transport material that can be used together with the PC copolymer of the present invention. Such compounds include carbazole compounds, indole compounds, imidazole compounds, oxazole compounds, pyrazole compounds, oxadiazole compounds, pyrazoline compounds, thiadiazole compounds, aniline compounds, hydrazone compounds, aromatic amine compounds, aliphatic amine compounds, stilbenes. Compound, fluorenone compound, butadiene compound, quinone compound, quinodimethane compound, thiazole compound, triazole compound, imidazolone compound, imidazolidine compound, bisimidazolidine compound, oxazolone compound, benzothiazole compound, benzimidazole compound, quinazoline compound, benzofuran compound, acridine Compound, phenazine compound, poly-N-vinylcarbazole, polyvinylpyrene, polyvinylanthra Emissions, polyvinyl acridine, poly-9-vinylphenyl anthracene, pyrene - formaldehyde resin, ethylcarbazole resin, or the like polymers having these structures in the main chain or side chain is preferably used. These compounds may be used individually by 1 type, and may be used in combination of 2 or more type.
Among these charge transport materials, compounds specifically exemplified in JP-A-11-172003 are particularly preferably used.
In the electrophotographic photoreceptor of the present invention, it is preferable to use the PC copolymer of the present invention as a binder resin in at least one of the charge generation layer and the charge transport layer.

  In the electrophotographic photosensitive member of the present invention, an undercoat layer that is usually used can be provided between the conductive substrate and the photosensitive layer. As this undercoat layer, fine particles such as titanium oxide, aluminum oxide, zirconia, titanic acid, zirconic acid, lanthanum lead, titanium black, silica, lead titanate, barium titanate, tin oxide, indium oxide, silicon oxide, polyamide Components such as resin, phenol resin, casein, melamine resin, benzoguanamine resin, polyurethane resin, epoxy resin, cellulose, nitrocellulose, polyvinyl alcohol, and polyvinyl butyral resin can be used. Further, as the resin used for the undercoat layer, the binder resin may be used, or the PC copolymer of the present invention may be used. These fine particles and resins can be used alone or in various mixtures. In the case of using these as a mixture, it is preferable to use inorganic fine particles and a resin together because a film having good smoothness is formed.

  The thickness of this undercoat layer is 0.01 μm or more and 10 μm or less, preferably 0.1 μm or more and 7 μm or less. If the thickness is less than 0.01 μm, it is difficult to form the undercoat layer uniformly, and if it exceeds 10 μm, the electrophotographic characteristics may be deteriorated. Further, a known blocking layer that is usually used can be provided between the conductive substrate and the photosensitive layer. As this blocking layer, the same kind of resin as the binder resin can be used. Moreover, you may use the PC copolymer of this invention. The blocking layer has a thickness of 0.01 μm to 20 μm, preferably 0.1 μm to 10 μm. When the thickness is less than 0.01 μm, it is difficult to form a blocking layer uniformly, and when it exceeds 20 μm, the electrophotographic characteristics may be deteriorated.

  Furthermore, a protective layer may be laminated on the photosensitive layer in the electrophotographic photoreceptor of the present invention. For this protective layer, the same kind of resin as the binder resin can be used. Further, it is particularly preferable to use the PC copolymer of the present invention. The thickness of this protective layer is 0.01 μm or more and 20 μm or less, preferably 0.1 μm or more and 10 μm or less. The protective layer contains a conductive material such as the charge generating substance, charge transporting substance, additive, metal or oxide thereof, nitride, salt, alloy, carbon black, or organic conductive compound. Also good.

  Further, in order to improve the performance of the electrophotographic photosensitive member, the charge generation layer and the charge transport layer include a binder, a plasticizer, a curing catalyst, a fluidity imparting agent, a pinhole control agent, a spectral sensitivity sensitizer ( Sensitizing dye) may be added. In addition, various chemical substances, antioxidants, surfactants, anti-curling agents, leveling agents, and other additives are added for the purpose of preventing increase in residual potential, decrease in charging potential, and reduction in sensitivity due to repeated use. Can be added.

  Examples of the binder include silicone resin, polyamide resin, polyurethane resin, polyester resin, epoxy resin, polyketone resin, polycarbonate resin, polystyrene resin, polymethacrylate resin, polyacrylamide resin, polybutadiene resin, polyisoprene resin, melamine resin, and benzoguanamine resin. , Polychloroprene resin, polyacrylonitrile resin, ethyl cellulose resin, nitrocellulose resin, urea resin, phenol resin, phenoxy resin, polyvinyl butyral resin, formal resin, vinyl acetate resin, vinyl acetate / vinyl chloride copolymer resin, polyester carbonate resin, etc. Can be mentioned. Also, heat and / or photocurable resins can be used. In any case, there is no particular limitation as long as it is an electrically insulating resin that can form a film in a normal state and does not impair the effects of the present invention.

  Specific examples of the plasticizer include biphenyl, biphenyl chloride, o-terphenyl, halogenated paraffin, dimethyl naphthalene, dimethyl phthalate, dibutyl phthalate, dioctyl phthalate, diethylene glycol phthalate, triphenyl phosphate, diisobutyl adipate, dimethyl sebacate, Examples include dibutyl sebacate, butyl laurate, methyl phthalyl ethyl glycolate, dimethyl glycol phthalate, methyl naphthalene, benzophenone, polypropylene, polystyrene, and fluorohydrocarbon.

  Specific examples of the curing catalyst include methanesulfonic acid, dodecylbenzenesulfonic acid, dinonylnaphthalenedisulfonic acid, and the like. Examples of the fluidity imparting agent include modaflow, acronal 4F, and the like. , Benzoin, and dimethyl phthalate. These plasticizers, curing catalysts, flow imparting agents, and pinhole control agents are preferably used at 5% by mass or less based on the charge transport material.

  Further, as a spectral sensitizer, when using a sensitizing dye, for example, triphenylmethane dyes such as methyl violet, crystal violet, knight blue, and victoria blue, erythrosin, rhodamine B, rhodamine 3R, acridine orange, Acridine dyes such as frappeosin, thiazine dyes such as methylene blue and methylene green, oxazine dyes such as capri blue and meldra blue, cyanine dyes, merocyanine dyes, styryl dyes, pyrylium salt dyes and thiopyrylium salt dyes are suitable.

  An electron-accepting substance can be added to the photosensitive layer for the purpose of improving sensitivity, reducing residual potential, and reducing fatigue during repeated use. Specific examples thereof include succinic anhydride, maleic anhydride, dibromomaleic anhydride, phthalic anhydride, tetrachlorophthalic anhydride, tetrabromophthalic anhydride, 3-nitrophthalic anhydride, 4-nitrophthalic anhydride, pyroanhydride Merit acid, merit anhydride, tetracyanoethylene, tetracyanoquinodimethane, o-dinitrobenzene, m-dinitrobenzene, 1,3,5-trinitrobenzene, p-nitrobenzonitrile, picryl chloride, quinone chloride, Chloranil, bromanyl, benzoquinone, 2,3-dichlorobenzoquinone, dichlorodicyanoparabenzoquinone, naphthoquinone, diphenoquinone, tropoquinone, anthraquinone, 1-chloroanthraquinone, dinitroanthraquinone, 4-nitrobenzophenone, 4,4'-dinini Lobenzophenone, 4-nitrobenzalmalondinitrile, ethyl α-cyano-β- (p-cyanophenyl) acrylate, 9-anthracenylmethylmalondinitrile, 1-cyano- (p-nitrophenyl) -2 -(P-chlorophenyl) ethylene, 2,7-dinitrofluorenone, 2,4,7-trinitrofluorenone, 2,4,5,7-tetranitrofluorenone, 9-fluorenylidene- (dicyanomethylenemalononitrile), polynitro- 9-fluorenylidene- (dicyanomethylenemalonodinitrile), picric acid, o-nitrobenzoic acid, p-nitrobenzoic acid, 3,5-dinitrobenzoic acid, pentafluorobenzoic acid, 5-nitrosalicylic acid, 3,5-dinitro Compounds with high electron affinity such as salicylic acid, phthalic acid, merit acid, etc. Masui. These compounds may be added to either the charge generation layer or the charge transport layer, and the blending ratio is 0.01 parts by mass or more and 200 parts by mass when the amount of the charge generation material or the charge transport material is 100 parts by mass. Hereinafter, it is preferably 0.1 parts by mass or more and 50 parts by mass or less.

In order to improve surface properties, tetrafluoroethylene resin, trifluoroethylene chloride resin, tetrafluoroethylene hexafluoropropylene resin, vinyl fluoride resin, vinylidene fluoride resin, difluorodiethylene chloride resin and Those copolymers and fluorine-based graft polymers may be used. The blending ratio of these surface modifiers is 0.1% by mass or more and 60% by mass or less, preferably 5% by mass or more and 40% by mass or less with respect to the binder resin. If the blending ratio is less than 0.1% by mass, surface modification such as surface durability and surface energy reduction is not sufficient, and if it is more than 60% by mass, electrophotographic characteristics may be degraded.

As the antioxidant, a hindered phenol antioxidant, an aromatic amine antioxidant, a hindered amine antioxidant, a sulfide antioxidant, an organic phosphate antioxidant, and the like are preferable. The blending ratio of these antioxidants is usually 0.01% by mass or more and 10% by mass or less, and preferably 0.1% by mass or more and 2% by mass or less with respect to the charge transport material.
As specific examples of such an antioxidant, compounds represented by the chemical formulas [Chemical Formula 94] to [Chemical Formula 101] described in the specification of JP-A No. 11-172003 are preferable.
These antioxidants may be used singly or in combination of two or more, and these may be added to the surface protective layer, the undercoat layer and the blocking layer in addition to the photosensitive layer. May be.

  Specific examples of the solvent used in the formation of the charge generation layer and the charge transport layer include, for example, aromatic solvents such as benzene, toluene, xylene, chlorobenzene, ketones such as acetone, methyl ethyl ketone, cyclohexanone, methanol, Alcohols such as ethanol and isopropanol, esters such as ethyl acetate and ethyl cellosolve, halogenated hydrocarbons such as carbon tetrachloride, carbon tetrabromide, chloroform, dichloromethane and tetrachloroethane, ethers such as tetrahydrofuran, dioxolane and dioxane, dimethylformamide, Examples thereof include dimethyl sulfoxide and diethylformamide. These solvents may be used alone or in combination of two or more.

The photosensitive layer of the single-layer type electrophotographic photosensitive member can be formed by applying the binder resin (PC copolymer) of the present invention using the charge generating material, charge transporting material, and additive. As the charge transport material, it is preferable to add the hole transport material and / or the electron transport material described above. As the electron transport material, those exemplified in JP-A-2005-139339 can be preferably applied.
Each layer can be applied using various known application apparatuses such as known ones. Specifically, for example, using an applicator, spray coater, bar coater, chip coater, roll coater, dip coater, doctor blade, etc. Can be done.

  The thickness of the photosensitive layer in the electrophotographic photosensitive member is 5 μm or more and 100 μm or less, preferably 8 μm or more and 50 μm or less. There is. The ratio of the charge generating material: binder resin used in the production of the electrophotographic photosensitive member is 1:99 to 30:70, preferably 3:97 to 15:85 in terms of mass ratio. The ratio of the charge transport material: binder resin is 10:90 to 80:20, preferably 30:70 to 70:30, in terms of mass ratio.

  Since the electrophotographic photoreceptor of the present invention thus obtained uses the PC copolymer of the present invention, the coating solution does not become cloudy and does not gel when the photosensitive layer is produced. In addition, since the photosensitive layer has a molded body (binder resin) made of the PC copolymer of the present invention, it has excellent durability (abrasion resistance) and excellent electrical characteristics (charging characteristics). Photoconductors that maintain excellent electrophotographic characteristics over a long period of time, such as copiers (monochrome, multicolor, full color; analog, digital), printers (lasers, LEDs, liquid crystal shutters), facsimile machines, plate-making machines, and these It is suitably used in various electrophotographic fields such as devices having a plurality of functions.

  In using the electrophotographic photosensitive member of the present invention, corona discharge (corotron, scorotron), contact charging (charging roll, charging brush) or the like is used for charging. Examples of the charging roll include a DC charging type and a DC charging type in which AC is superimposed. For the exposure, any of a halogen lamp, a fluorescent lamp, a laser (semiconductor, He—Ne), an LED, and a photoreceptor internal exposure method may be adopted. For the development, dry development methods such as cascade development, two-component magnetic brush development, one-component insulating toner development, and one-component conductive toner development are used. For transfer, electrostatic transfer methods such as corona transfer, roller transfer, and belt transfer, pressure transfer methods, and adhesive transfer methods are used. For fixing, heat roller fixing, radiant flash fixing, open fixing, pressure fixing, or the like is used. Further, a brush cleaner, a magnetic brush cleaner, an electrostatic brush cleaner, a magnetic roller cleaner, a blade cleaner, and a cleaner omitted are used for cleaning and static elimination. Further, as the resin for toner, a styrene resin, a styrene-acrylic copolymer resin, a polyester, an epoxy resin, a cyclic hydrocarbon polymer, or the like can be applied. The shape of the toner may be spherical or indeterminate, and can be applied even if it is controlled to a certain shape (spheroid, potato, etc.). The toner may be any of a pulverizing type, a suspension polymerization toner, an emulsion polymerization toner, a chemical granulation toner, or an ester extension toner.

  Next, the present invention will be described in more detail with reference to examples and comparative examples. However, the present invention is not limited to these examples, and various modifications and applications can be made without departing from the spirit of the present invention. Is possible.

[Production Example: Preparation of Oligomer]
<Production Example 1: Synthesis of bisphenol Z oligomer (bischloroformate)>
73.0 g (0.272 mol) of 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z) was suspended in 410 mL of methylene chloride, and 55.3 g (0.546 mol) of triethylamine was added and dissolved therein. . This was dropwise added to a solution obtained by dissolving 54.5 g (0.551 mol) of phosgene in 225 mL of methylene chloride at 14 to 18.5 ° C. over 2 hours and 50 minutes. After stirring at 18.5 ° C to 19 ° C for 1 hour, 250 mL of methylene chloride was distilled off at 10 to 22 ° C. The remaining liquid was washed with 73 mL of pure water, 4.5 mL of concentrated hydrochloric acid, and 0.47 g of hydrosulfite. Thereafter, washing with 330 mL of pure water was repeated four times to obtain a methylene chloride solution of a bisphenol Z oligomer having a chloroformate group at the molecular end. The resulting solution had a chloroformate concentration of 0.91 mol / L, a solid concentration of 0.22 kg / L, and an average number of monomers of 1.31. Further, the content of the amide compound contained in the obtained bisphenol Z oligomer is a value obtained by subtracting the nitrogen amount derived from triethylamine from the total nitrogen mass in the bisphenol Z oligomer, and is 90 mass ppm on the basis of the mass of the bisphenol Z oligomer. I found out. Moreover, the amount of nitrogen derived from triethylamine was 0.3 mass ppm. In addition, the nitrogen mass in bisphenol Z oligomer determined the total nitrogen amount according to the chemiluminescence method based on JISK2609. From this, the amount of triethylamine was quantified by gas chromatography analysis, which was converted into the amount of nitrogen and subtracted from the total amount of nitrogen to obtain the mass of nitrogen derived from the amide compound. Hereinafter, the obtained raw material is referred to as Z-CF.

The total amount of nitrogen was quantified using TS-100 manufactured by Mitsubishi Chemical Analytech Co., Ltd. according to JIS K2609 (chemiluminescence method). The JIS standard describes a measurement method related to a liquid, but a solid sample was measured with a similar apparatus.
From a solution of bischloroformate compound in methylene chloride, methylene chloride was dried at 50 ° C. under reduced pressure. Measurement was performed using the obtained solid content. The nitrogen content was quantified by comparing this result with a calibration curve prepared separately using pyridine as a standard substance. The total nitrogen content in the bischloroformate compound was calculated by converting the obtained results into the concentration of the bischloroformate compound in methylene chloride.
The triethylamine was quantified by adding 0.5N-NaOH aqueous solution to the solid content of the bischloroformate compound obtained by the above method to adjust the pH to 8 or more, adding chloroform to this, and using the chloroform extract component as triethylamine. Gas chromatographic analysis was performed and quantification was performed by an absolute calibration curve method.

The conditions for gas chromatography analysis are as follows.
Model: 7890A made by Agilent Technologies
Column: CP-VOLAMINE (manufactured by Varian) 60 m × 0.32 mm (inner diameter)
Inlet temperature: 150 ° C
Column temperature: raised from 40 ° C. to 150 ° C. at 50 ° C./minute, held at 150 ° C. for 10 minutes, then raised to 250 ° C. at 50 ° C./minute Carrier gas: helium 40 cm / second Constant injection volume: 2 μL
Injection method: Splitless detector: FID
FID temperature: 260 ° C

In addition, the average number of oligomers (n ′) was obtained using the following formula.
Average number of monomer (n ′) = 1+ (Mav−M1) / M2 (Equation 1)
(In the formula (Equation 1), Mav is (2 × 1000 / (CF value)), M2 is (M1-98.92), and M1 is n ′ = 1 in the formula (4). The CF value (N / kg) is (CF value / concentration), and the CF value (N) is a bischloroformate compound represented by the above formula (4) contained in 1 L of the reaction solution. It is the number of chloro molecules in the chloroformate compound, and the concentration (kg / L) is the amount of solid content obtained by concentrating 1 L of the reaction solution, where 98.92 is between the bischloroformate compounds. (The total atomic weight of two chlorine atoms, one oxygen atom, and one carbon atom eliminated by polycondensation.)

<Production Example 2: Synthesis of 1,1-bis (4-hydroxyphenyl) -cyclododecane oligomer (bischloroformate)>
43.6 g (0.124 mol) of 1,1-bis (4-hydroxyphenyl) -cyclododecane was suspended in 410 mL of methylene chloride, and 25.0 g (0.248 mol) of triethylamine was added thereto and dissolved. The solution was added dropwise to a solution obtained by dissolving 24.8 g (0.250 mol) of phosgene in 225 mL of methylene chloride at 14 to 18.5 ° C. over 2 hours and 50 minutes. After stirring at 18.5 ° C to 19 ° C for 1 hour, 250 mL of methylene chloride was distilled off at 10 to 22 ° C. The remaining liquid was washed with 73 mL of pure water, 4.5 mL of concentrated hydrochloric acid, and 0.47 g of hydrosulfite. Thereafter, washing with 330 mL of pure water was repeated four times to obtain a methylene chloride solution of 1,1-bis (4-hydroxyphenyl) -cyclododecane oligomer having a chloroformate group at the molecular end. The resulting solution had a chloroformate concentration of 0.92 mol / L, a solid concentration of 0.23 kg / L, and an average number of monomers of 1.06. The content of the amide compound in the obtained 1,1-bis (4-hydroxyphenyl) -cyclododecane oligomer was found to be 210 mass ppm. Moreover, the amount of nitrogen derived from triethylamine was 0.3 mass ppm. Hereinafter, the obtained raw material is referred to as CDE-CF.

<Production Example 3: Synthesis of 2,2-bis (4-hydroxyphenyl) -adamantane oligomer (chloroformate)>
To a mixed liquid of 33.0 g (0.103 mol) of 2,2-bis (4-hydroxyphenyl) adamantane, 330 ml of methylene chloride and 30.6 g (0.309 mol) of phosgene, 23.2 g (0.229 mol) of triethylamine and chloride The same operation as in Production Example 4 was conducted except that a liquid mixed with 66 ml of methylene was dropped. 288.2 g of bischloroformate containing solution was obtained.
The resulting solution had a chloroformate concentration of 0.87 mol / L, a solid concentration of 0.21 kg / L, and an average number of monomers of 1.11. In addition, it turned out that content of the amide compound in the obtained 2, 2-bis (4-hydroxyphenyl) -adamantane oligomer is 410 mass ppm. Moreover, the amount of nitrogen derived from triethylamine was 0.3 mass ppm. Hereinafter, the obtained raw material is referred to as 22Ad-CF.

<Production Example 4: Synthesis of bisphenol Z oligomer (chloroformate)>
60.0 kg (224 mol) of 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z) was suspended in 1080 L of methylene chloride, and 66.0 kg (667 mol) of phosgene was added and dissolved therein. A solution obtained by dissolving 44.0 kg (435 mol) of triethylamine in 120 L of methylene chloride was added dropwise thereto at 2.2 to 17.8 ° C. over 2 hours and 50 minutes. After stirring at 17.9 to 19.6 ° C. for 30 minutes, 900 L of methylene chloride was distilled off at 14 to 20 ° C. 210 L of pure water, 1.2 kg of concentrated hydrochloric acid, and 450 g of hydrosulfite were added to the remaining liquid for washing. Thereafter, washing with 210 L of pure water was repeated 5 times to obtain a methylene chloride solution of a bisphenol Z oligomer having a chloroformate group at the molecular end. The resulting solution had a chloroformate concentration of 1.14 mol / L, a solid concentration of 0.23 kg / L, and an average number of monomers of 1.02. In addition, it turned out that content of the amide compound in the obtained bisphenol Z oligomer is 20 mass ppm. Moreover, the amount of nitrogen derived from triethylamine was 0.3 mass ppm. Hereinafter, the obtained raw material is referred to as Z-CF2.

<Production Example 5: Synthesis of bisphenol Z oligomer (chloroformate)>
In Production Example 1, production was conducted in the same manner as in Production Example 1 except that the number of pure water washings performed after the synthesis reaction of bisphenol Z oligomer (Z-CF) was reduced from 4 times to 2 times.
In addition, it turned out that content of the amide compound in the obtained bisphenol Z oligomer is 720 mass ppm. Hereinafter, the obtained raw material is referred to as Z-CF3.

[Example 1]
(Production of PC copolymer)
A mechanical stirrer, a stirring blade, and a baffle plate were attached to the reaction vessel, and methylene chloride (51 mL) was added to Z-CF (9 mL) obtained in Production Example 1. To this, p-tert-butylphenol (hereinafter referred to as PTBP) (0.02 g) was added as a terminal terminator, and the mixture was stirred so as to be sufficiently mixed. A total amount of a separately prepared monomer solution was added to this solution (monomer solution preparation method: 12 mL of 2N aqueous potassium hydroxide solution was prepared, cooled to room temperature or lower, 0.1 g of hydrosulfite, and 2,7-dihydroxy Naphthalene (1.1 g) was added and completely dissolved, and 0.2 mL of triethylamine aqueous solution (7 vol%) was added with stirring, and stirring was continued for 1 hour.
The obtained reaction mixture was diluted with 0.2 L of methylene chloride and 0.1 L of water and washed. The lower layer was separated, and further washed with 0.1 L of water, once with 0.1 L of 0.03N hydrochloric acid, and once with 0.1 L of water three times. The obtained methylene chloride solution was dropped into methanol with stirring, and the obtained reprecipitate was filtered and dried to obtain a polycarbonate copolymer (PC-1) having the following structure.

(Specification of PC copolymer)
The polycarbonate copolymer (PC-1) thus obtained was dissolved in methylene chloride to prepare a solution having a concentration of 0.5 g / dl, and the reduced viscosity [ηsp / C] at 20 ° C. was measured. 1.13 dl / g. When the structure and composition of the obtained PC-1 were analyzed by ¹ H-NMR spectrum and ¹³ C-NMR spectrum, it was a polycarbonate copolymer composed of the following repeating units, the number of repeating units, and the composition. confirmed. Further, it was found that the residual amount of diethylcarbamic acid chloride in the obtained polycarbonate copolymer was 10 ppm by mass based on the total mass of the polycarbonate copolymer.

n = 2.46, Ar ² / (Ar ¹ + Ar ² ) = 0.29

The structure in the formula (1) was confirmed by the following procedure. First, it was confirmed that there was no bond between Ar ² using a ¹³ C-NMR spectrum, and then a copolymerization ratio of Ar ¹ and Ar ² was calculated from a ¹ H-NMR spectrum. Subsequently, the value of n was calculated by the following formula (Formula 2).
Ar ² / (Ar ¹ + Ar ² ) = 1 / (n + 1) (Equation 2)

(Manufacture of coating solution and electrophotographic photoreceptor)
Using a polyethylene terephthalate resin film deposited with aluminum metal as the conductive substrate, a charge generating layer and a charge transport layer were sequentially laminated on the surface to produce an electrophotographic photoreceptor having a laminated photosensitive layer. 0.5 parts by mass of oxotitanium phthalocyanine was used as the charge generating substance, and 0.5 parts by mass of butyral resin was used as the binder resin. These were added to 19 parts by mass of methylene chloride as a solvent, dispersed by a ball mill, and this dispersion was applied to the surface of the conductive substrate film by a bar coater and dried to give a film thickness of about 0.5 microns. A charge generation layer was formed.
Next, 0.5 g of the compound (CTM-1) of the following formula (12) and 0.5 g of the polycarbonate copolymer (PC-1) obtained above were dispersed in 10 ml of tetrahydrofuran as a charge transport material, A coating solution was prepared. This coating solution was applied onto the charge generation layer with an applicator and dried to form a charge transport layer having a thickness of about 20 microns.

(Evaluation of PC copolymer and electrophotographic photoreceptor)
The solubility of the PC copolymer was evaluated by visually observing the white turbidity of the prepared coating solution when the coating solution was prepared. The case where the PC copolymer was dissolved and no white turbidity was observed was indicated as “◯”, the case where it was cloudy as “white turbidity”, and the case where there was an insoluble part as “X”.
In addition, the wear resistance of the PC copolymer and the electrophotographic photosensitive member was evaluated as follows.
[1] Preparation of copolymer abrasion resistance sample: PC-1 (2 g) was dissolved in methylene chloride (12 mL), and cast on a commercially available PET film using an applicator. This film was heated under reduced pressure to remove the solvent, and a film sample having a thickness of about 30 μm was obtained.
[2] Photoreceptor wear resistance evaluation sample preparation: PC-1 (1 g) and CTM-1 (1 g) are dissolved in methylene chloride (10 mL), and cast on a commercially available PET film using an applicator. did. This film was heated under reduced pressure to remove the solvent, and a film sample having a thickness of about 30 μm was obtained.
[3] Evaluation: The abrasion resistance of the cast surface of the film produced in [1] and [2] was evaluated using a Suga abrasion tester NUS-ISO-3 type (manufactured by Suga Test Instruments Co., Ltd.). The test condition was that the abrasion paper (containing alumina particles having a particle diameter of 3 μm) applied with a load of 4.9 N was brought into contact with the surface of the photosensitive layer and 2,000 reciprocating motions were performed to measure the mass loss.
[4] Measurement of content of impurities (diethylcarbamic acid chloride) contained in the PC copolymer: Diethylcarbamic acid chloride was measured by an absolute calibration curve method using gas chromatography.
The measurement conditions are as follows.
Sample: 0.5 g of PC copolymer was dissolved in 13.3 g of methylene chloride to prepare a measurement sample.
Equipment: 7890A manufactured by Agilent Technologies
Column: HP-1 30 m × 0.25 mm (inner diameter) (film thickness: 0.25 μm)
Temperature: raised from 40 ° C. to 300 ° C. at 10 ° C. per minute and held at 300 ° C. for 30 minutes Inlet: Split 300 ° C.
Detector: 310 ° C (FID)
Carrier gas: Helium 40 cm / sec Injection amount: 1 μL

Next, the electrophotographic characteristics of the electrophotographic photosensitive member were measured using an electrostatic charge test apparatus EPA-8100 (manufactured by Kawaguchi Electric Manufacturing Co., Ltd.). Static mode, -6 kV corona discharge, initial surface potential (V ₀ ), residual potential after 5 seconds of light irradiation (10 Lux) (initial residual potential (V _R )), half exposure (E _1/2 ) It was measured. In addition, a commercially available printer (FS-600, manufactured by Kyocera) is modified so that the surface potential of the photoconductor can be measured, and the photoconductor can be mounted and evaluated in a drum shape, under high temperature and high humidity conditions (35 ° C, 85%), the toner, the evaluation of charge characteristics before and after the 24-hour repeated operation paper under the condition that does not pass (repeating residual potential rise (V _R increases)) was performed.
These results are shown in Table 1, and the same evaluation was performed for Examples 2 to 4D and Comparative Examples 1 to 4 described later, and the results are shown in Table 1.

[Example 2]
In Example 1, except that Z-CF was changed to 18 mL of CDE-CF, the amount of methylene chloride was changed to 42 mL, the amount of PTBP was changed to 0.02 g, and 2,7-dihydroxynaphthalene was changed to 0.8 g of resorcin. Was performed in the same manner as in Example 1 to obtain PC-2.
[Ηsp / C] of PC-2 was 1.11 dl / g, and in the above formula (1), it was confirmed to be a PC copolymer comprising the following repeating units and compositions. Further, it was found that the residual amount of diethylcarbamic acid chloride in the obtained polycarbonate copolymer was 20 ppm by mass based on the total mass of the polycarbonate copolymer.

n = 2.0, Ar ² / (Ar ¹ + Ar ² ) = 0.33

Example 3
In Example 1, Z-CF was changed to 18 mL of 22Ad-CF, the amount of methylene chloride was changed to 42 mL, the amount of PTBP was changed to 0.03 g, and 2,7-dihydroxynaphthalene was changed to 4,4′-biphenol. PC-3 was obtained in the same manner as in Example 1 except that the amount was changed to 1 g and the amount of 2N potassium hydroxide aqueous solution was changed to 13 mL.
[Ηsp / C] of PC-3 was 1.13 dl / g, and in the above formula (1), it was confirmed to be a PC copolymer comprising the following repeating units and compositions. The residual amount of diethylcarbamic acid chloride in the obtained polycarbonate copolymer was found to be 35 ppm by mass based on the total mass of the polycarbonate copolymer.

n = 2.0, Ar ² / (Ar ¹ + Ar ² ) = 0.33

Example 4
A PC copolymer (PC-4) was produced in the same manner as in Example 1 except that 1.1 g of 2,7-dihydroxynaphthalene was changed to 1.8 g of 4,4′-biphenol.
The reduced viscosity [ηsp / C] of PC-4 was 1.16 dl / g, and the structure was confirmed to be a PC copolymer comprising the following repeating units and compositions in the above formula (1). The residual amount of diethylcarbamic acid chloride in the obtained polycarbonate copolymer was found to be 15 ppm by mass based on the total mass of this polycarbonate copolymer.

n = 2.13, Ar ² / (Ar ¹ + Ar ² ) = 0.32.

Example 4A
A mechanical stirrer, a stirring blade, and a baffle plate were attached to the reaction vessel, and Z-CF2 (24 mL) and methylene chloride (36 mL) obtained in Production Example 4 were injected. To this, p-tert-butylphenol (hereinafter referred to as PTBP) (0.04 g) and 0.2 g of a siloxane-modified phenol represented by the following formula (4A) were added as a terminal stopper, and the mixture was stirred so as to be sufficiently mixed. .
A total amount of a separately prepared biphenol monomer solution was added to this solution (monomer solution preparation method: 10 mL of 2N sodium hydroxide aqueous solution was prepared, cooled to room temperature or lower, 0.1 g of hydrosulfite as an antioxidant, After adding 2.6 g of 4,4′-biphenol and completely dissolving it, the reactor was cooled until the temperature in the reactor reached 15 ° C., and then 0.2 mL of an aqueous triethylamine solution (7 vol%) was stirred. Added and continued stirring for 1 hour.
The obtained reaction mixture was diluted with 0.2 L of methylene chloride and 0.1 L of water and washed. The lower layer was separated, and further washed with 0.1 L of water, once with 0.1 L of 0.03N hydrochloric acid, and 5 times with 0.1 L of water in this order. The obtained methylene chloride solution was dropped into warm water with stirring to evaporate the methylene chloride and obtain a resin solid. The obtained precipitate was filtered and dried to produce a polycarbonate copolymer (PC-4A) having the following structure. In addition, the mass ratio of the organosiloxane modified phenyl group portion in the PC copolymer (PC-4A) is 3% by mass based on the total mass of the PC copolymer. In the following formula 4A, n = 39.

  The reduced viscosity [ηsp / C] of PC-4A was 1.16 dl / g, and the structure was confirmed to be a PC copolymer comprising the following repeating units and compositions in the above formula (1). Further, the content of diethylcarbamic acid chloride contained in the PC copolymer was 5 ppm.

n = 1.38, Ar ² / (Ar ¹ + Ar ² ) = 0.42

[Example 4B]
A PC copolymer (PC-4B) was produced in the same manner as in Example 4A, except that in Example 4A, the siloxane-modified bisphenol was changed to 0.4 g of siloxane-modified phenol represented by the following formula (4B). In addition, the mass ratio of the organosiloxane modified phenyl group portion in the PC copolymer (PC-4B) is 5% by mass based on the total mass of the PC copolymer. In the following formula 4B, n = 90.

  The reduced viscosity [ηsp / C] of PC-4B was 1.16 dl / g, and the structure was confirmed to be a PC copolymer composed of the following repeating units and compositions in the above formula (1). Further, the content of diethylcarbamic acid chloride contained in the PC copolymer was 5 mass ppm.

n = 1.38, Ar ² / (Ar ¹ + Ar ² ) = 0.42

[Example 4C]
A PC copolymer (PC-4C) was produced in the same manner as in Example 4A, except that in Example 4A, the siloxane-modified bisphenol was changed to 0.2 g of siloxane-modified phenol represented by the following formula (4C). In addition, the mass ratio of the organosiloxane modified phenyl group portion in the PC copolymer (PC-4B) is 5% by mass based on the total mass of the PC copolymer. In the following formula 4C, n = 150.

  The reduced viscosity [ηsp / C] of PC-4C was 1.16 dl / g, and the structure was confirmed to be a PC copolymer consisting of the following repeating units and compositions in the above formula (1). Further, the content of diethylcarbamic acid chloride contained in the PC copolymer was 5 mass ppm.

n = 1.38, Ar ² / (Ar ¹ + Ar ² ) = 0.42

Example 4D
A PC copolymer (PC-4D) was produced in the same manner as in Example 4A, except that in Example 4A, the siloxane-modified bisphenol was changed to 0.2 g of the siloxane-modified phenol represented by the following formula (4D). In addition, the mass ratio of the organosiloxane modified phenyl group part in the PC copolymer (PC-4D) is 5% by mass based on the total mass of the PC copolymer. In the following formula 4D, n = 60. Further, the content of diethylcarbamic acid chloride contained in the PC copolymer was 5 mass ppm.

n = 1.38, Ar ² / (Ar ¹ + Ar ² ) = 0.42.

  The PC copolymers obtained in Examples 4A to 4D were further evaluated for water contact angle and toner adhesion as follows.

(Evaluation of water contact angle)
A film was prepared with the PC copolymer alone, and the contact angle with ultrapure water was measured using this film.
For measuring the contact angle, DM700 (manufactured by Kyowa Interface Science Co., Ltd.) was used as a measuring device.

(Evaluation of toner adhesion)
As described above, an electrophotographic photosensitive member was produced using a PC copolymer and evaluated using a commercially available printer (FS-600, manufactured by Kyocera Corporation).
Specifically, the electrophotographic photosensitive member was mounted on a printer in a drum shape, and was repeatedly operated for 1 hour under normal temperature and normal humidity conditions (23 ° C., 50%).
And the adhesion state in the fixed range (2 cm x 2 cm square) of the center of an electrophotographic photoreceptor was confirmed visually. The evaluation criteria are as follows.

(Evaluation criteria)
A: No toner adheres within the evaluation range of the electrophotographic photosensitive member.
○: Slight adhesion of toner. It can be removed by blowing air.
X: Toner adheres. Cannot be removed by blowing air.

Comparative Example 1
According to Example 2 of JP-A-5-70582, a PC copolymer (PC-5) having a mass average molecular weight in terms of GPC polystyrene of 60,000 was produced as follows.
625 mL of methylene chloride was added to a reaction vessel equipped with a stirrer and a thermometer, and 35.3 g of bisphenol A bischloroformate was added and dissolved while stirring. Furthermore, after adding 125 mL of ion-exchange water to this, the liquid which melt | dissolved 18.6 g of biphenols in 228.6 g of 3.5% sodium hydroxide aqueous solution was dripped at 20-25 degreeC in 1 hour, fully stirring. After dropping, stirring was continued at the same temperature, and after 4 hours, 14.3 g of 28% sodium hydroxide aqueous solution was added and stirring was further continued for 5 hours. When the molecular weight reached 60,000 (GPC, converted to polystyrene), stirring was stopped. And left to stand.
The obtained reaction solution was poured into ice water, and the precipitated crystals were collected by filtration, washed with water, dried and then recrystallized with acetone to obtain PC-5.
The reduced viscosity [ηsp / C] of the present PC copolymer was 0.53 dl / g.

[Comparative Example 2]
1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z) (0.17 kg) and 4,4′-biphenol (0.03 kg) in 1.5 L of 2N aqueous potassium hydroxide solution and methylene chloride While mixing with 0 kg and stirring, phosgene gas was blown into the liquid at a rate of 1 L / min until the pH was 9 or less. Subsequently, this reaction liquid was left and separated to obtain a methylene chloride solution of an oligomer having a degree of polymerization of 2 to 6 in the organic layer and having a chloroformate group at the molecular end.
Next, a mechanical stirrer, a stirring blade, and a baffle plate were attached to the reaction vessel, and methylene chloride (34 mL) was added to the oligomer (26 mL). To this, PTBP (0.065 g) was added as a terminal terminator and stirred to ensure sufficient mixing. A total amount of a separately prepared biphenol monomer solution was added to this solution (monomer solution preparation method: 15 mL of 2N aqueous sodium hydroxide solution was prepared and cooled to room temperature or lower, and then 0.02 g, 4,4 ′ hydrosulfite was added. -1.2 g of biphenol was added and completely dissolved), and 0.2 mL of an aqueous solution of triethylamine (7 vol%) was added while stirring, and stirring was continued for 1 hour.
The obtained reaction mixture was diluted with 0.2 L of methylene chloride and 0.1 L of water and washed. The lower layer was separated, and further washed with 0.1 L of water, once with 0.1 L of 0.01N hydrochloric acid, and three times with 0.1 L of water. The obtained methylene chloride solution was dropped into methanol with stirring, and the obtained reprecipitate was filtered and dried to obtain a PC copolymer (PC-6).
The reduced viscosity [ηsp / C] of PC-6 was 1.10 dl / g. Moreover, it was confirmed that the repeating unit derived from 4,4'-biphenol exists in this PC copolymer as a component which connected 2 or more through the carbonate bond.

[Comparative Example 3]
A solution prepared by dissolving 0.2 kg of 1,1-bis (4-hydroxyphenyl) cyclohexane in 1.2 kg of a 16 wt% aqueous potassium hydroxide solution and 1.3 kg of methylene chloride was mixed and stirred while cooling. Phosgene gas was blown into the liquid at a rate of 1 L / min until the pH was 9 or less. The reaction solution was then allowed to stand and separate to obtain an methylene chloride solution of an oligomer having a degree of polymerization of 2 to 6 in the organic layer and having a chloroformate group at the molecular end.
Next, a mechanical stirrer, a stirring blade, and a baffle plate were attached to the reaction vessel, and 190 mL of methylene chloride was added to the oligomer (260 mL). P-tert-Butylphenol (0.40 g) was added as an end terminator and stirred to ensure thorough mixing. After adding 30 mL of 2N potassium hydroxide aqueous solution prepared separately to this solution, 1 mL of triethylamine aqueous solution (7 vol%) was added, stirring. Ten minutes later, the whole amount of a separately prepared biphenol monomer solution was added (monomer solution preparation method: 120 mL of 2N aqueous potassium hydroxide solution was prepared and cooled to room temperature or lower, and then 0.1 g of hydrosulfite, 1,1- (17.3 g of bis (4-hydroxyphenyl) cyclohexane was added and completely dissolved), and stirring was continued for 1 hour.
The obtained reaction mixture was diluted with 2 L of methylene chloride and 1 L of water and washed. The lower layer was separated, and further washed with 1 L of water, once with 1 L of 0.01N hydrochloric acid, and 3 times with 1 L of water. The obtained methylene chloride solution was dropped into methanol with stirring, and the obtained reprecipitate was filtered and dried to obtain a PC copolymer (PC-7).
The reduced viscosity [ηsp / C] of PC-7 was 1.14 dl / g. Further, the n value exceeded 3.00.

[Comparative Example 4]
A PC copolymer (PC-) was prepared in the same manner as in Example 4 except that the bisphenol Z oligomer (Z-CF) used in Example 4 was changed to the bisphenol Z oligomer (Z-CF3) produced in Production Example 5. 8) was produced. The structure and reduced viscosity of the PC copolymer (PC-8) are the same as in Example 4. Further, the content of diethylcarbamic acid chloride contained in the PC copolymer was 110 ppm.

〔Evaluation results〕
Table 1 shows the evaluation results of Examples 1 to 4D and Comparative Examples 1 to 4. Comparing Examples 1 to 4D and Comparative Examples 1 to 4, the PC copolymers of Examples 1 to 4D maintain stable solubility in organic solvents and have a mass reduction amount in the wear resistance evaluation. Was found to be excellent in wear resistance. Further, in the electrophotographic photoreceptor of Example 1～4D, a smaller value of an initial residual potential (V _R), since repeating residual potential (V _R increases) is small, the wear resistance, electrical characteristics, and charging characteristics It turns out that everything is excellent.
On the other hand, the PC copolymer of Comparative Example 1 was not dissolved in the solvent, and the coating solution could not be prepared. The PC copolymer of Comparative Example 2 has poor solubility, and the electrophotographic photosensitive member shows large values for both the initial residual potential and the repeated residual potential, indicating that the electrical characteristics and charging characteristics are poor. In the PC copolymer of Comparative Example 3, it was found that the amount of mass loss was large in the wear resistance evaluation, and the wear resistance was poor.

Moreover, in Examples 1-4D, since the frequency | count of washing | cleaning of bischloroformate was increased, the amount of impurities hardly remained in the PC copolymer, and the initial residual potential and the repeated residual potential were good. However, in Comparative Example 4, it was found that since the number of washings of bischloroformate was small, a large amount of impurities remained in the PC copolymer, and the initial residual potential and the repeated residual potential deteriorated.
Further, as shown in Table 2, in Examples 4A to 4C, the PC copolymer has a divalent organosiloxane-modified phenylene group, and in Example 4D, the PC copolymer has a monovalent organosiloxane. Since it has a modified phenyl group, it was found that the contact angle of water and the toner adhesion were improved as compared with Example 4 having no organosiloxane-modified phenyl group.
In Table 1, “* impurity content” represents the amount of diethylcarbamic acid chloride.

  The polycarbonate copolymer of the present invention can be suitably used as a binder resin for a photosensitive layer of an electrophotographic photoreceptor.

Claims (12)

It has a structure composed of repeating units represented by the following formula (1), and the molar copolymer composition represented by Ar ² / (Ar ¹ + Ar ² ) is 25 mol% or more and 47 mol% or less. Polycarbonate copolymer.
{In the formula, Ar ¹ is a group represented by the following formula (2); Ar ² is a substituted or unsubstituted biphenol, dihydroxynaphthalene, hydroquinone, resorcin, catechol, 9,9-bis (hydroxyphenyl) fluorene. Or a divalent group derived from 4,4′-dihydroxydiphenylmethane. n is the average number of repetitions of Ar ¹ block and represents a number of 1.09 or more and 3.00 or less. }
{Wherein, R ^1, R ² is a hydrogen atom, a halogen atom, a trifluoromethyl group, an alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted aryl group having 6 to 12 carbon atoms, 1 to 12 carbon atoms An alkoxy group, a substituted or unsubstituted aryloxy group having 6 to 12 carbon atoms. In R ¹ and R ² , a plurality of groups may be added to one aromatic ring. In this case, the plurality of groups may be the same or different from each other. X represents a substituted or unsubstituted cycloalkylidene group having 5 to 20 carbon atoms, a substituted or unsubstituted bicyclo or tricyclohydrocarbon diyl group having 5 to 20 carbon atoms, or a group represented by the following formula (3). . }
(Wherein R ^{5 to} R ⁷ are each independently a hydrogen atom, an alkyl group having 1 to 12 carbon atoms, a trifluoromethyl group, or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.) The polycarbonate copolymer according to claim 1,
A polycarbonate copolymer further comprising a divalent organosiloxane-modified phenylene group as Ar ² . The polycarbonate copolymer according to claim 2,
The polycarbonate copolymer, wherein the divalent organosiloxane-modified phenylene group is a group represented by the following formula (2A) or (2B):
(In Formula (2A), R ²¹ and R ²² are each independently a hydrogen atom, a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, or a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms. Or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
R ²³ is each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
n1 is an integer of 2 to 4, and n2 is an integer of 1 to 600. )
(In formula (2B), each R ³¹ is independently a halogen atom, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, or a 6 to 12 carbon number. These are substituted or unsubstituted aryl groups.
R ³² is each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
R ³³ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond.
R ³⁴ is the same or different monovalent hydrocarbon group not containing an aliphatic unsaturated bond.
Y and Y ′ are an alkylene group having 2 or more carbon atoms, an alkyleneoxyalkylene, or an oxygen atom.
na is 0 or 1, nb is 1 or 2, and nc is 1 or 2. However, na + nb + nc is 3.
n1 to n4 are each an integer of 0 or more, the sum of n1, n2, n3, and n4 is an integer of 2 to 600, and the sum of n3 and n4 is an integer of 1 or more.
a is 0 or an integer from 1 to 4. ) The polycarbonate copolymer according to any one of claims 1 to 3,
A polycarbonate copolymer, wherein a chain end is sealed with a monovalent aromatic group or a monovalent fluorine-containing aliphatic group. The polycarbonate copolymer according to claim 4,
A polycarbonate copolymer, wherein the monovalent aromatic group at the chain end is a monovalent organosiloxane-modified phenyl group. The polycarbonate copolymer according to claim 5,
The polycarbonate copolymer, wherein the monovalent organosiloxane-modified phenyl group is a group represented by the following formula (2C).
(Z is a C2-C6 hydrocarbon group.
R ⁴¹ is an aliphatic hydrocarbon group having 1 to 6 carbon atoms.
R ^{42 to} R ⁴⁵ are each independently hydrogen, a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms, a substituted or unsubstituted alkoxy group having 1 to 12 carbon atoms, a substituted or unsubstituted group having 6 to 12 carbon atoms. An aryl group.
R ^{46 to} R ⁴⁹ are each independently a substituted or unsubstituted alkyl group having 1 to 12 carbon atoms or a substituted or unsubstituted aryl group having 6 to 12 carbon atoms.
n is a number of 2 to 600, and indicates the average number of repeating units when it has a molecular weight distribution. ) The polycarbonate copolymer according to any one of claims 1 to 6,
A polycarbonate copolymer, characterized in that the bischloroformate oligomer represented by the following formula (4) is used as a raw material, and the average number of oligomers (n ′) of the bischloroformate oligomer is 1.0 or more and 1.99 or less. Polymer.
The polycarbonate copolymer according to any one of claims 1 to 7,
Ar ¹ represented by the formula (2) is 1,1-bis (4-hydroxyphenyl) cyclohexane, 1,1-bis (4-hydroxyphenyl) cyclopentane, 1,1-bis (4-hydroxyphenyl). ) Cyclododecane, 2,2-bis (4-hydroxyphenyl) adamantane, 1,3-bis (4-hydroxyphenyl) adamantane, 1,1-bis (4-hydroxyphenyl) -3,3,5-trimethylcyclohexane Or a divalent group derived from a group selected from the group represented by the formula (3). A polycarbonate copolymer according to claim 7 or claim 8,
When the amide compound is contained in the raw material containing the bischloroformate oligomer represented by the formula (4),
The content of the amide compound is determined based on the mass of nitrogen atoms contained in the raw material containing the bischloroformate oligomer, and is 700 mass ppm based on the total mass of the raw material containing the bischloroformate oligomer excluding the solvent. A polycarbonate copolymer characterized by the following: The polycarbonate copolymer according to any one of claims 1 to 9,
When the polycarbonate copolymer contains dialkylcarbamic acid chloride,
Content of the said dialkyl carbamic acid chloride is 100 mass ppm or less on the basis of the total mass of the said polycarbonate copolymer. Polycarbonate copolymer characterized by the above-mentioned.   A coating liquid comprising the polycarbonate copolymer according to any one of claims 1 to 10 and an organic solvent. An electrophotographic photoreceptor having a photosensitive layer on a conductive substrate,
An electrophotographic photoreceptor comprising the polycarbonate copolymer according to any one of claims 1 to 10 as one component of the photosensitive layer.