JP2003206349A - Polycarbonate copolymer, its manufacturing method, and electrophotographic photoreceptor using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a polycarbonate copolymer which, less in the nitrogen introduced in the molecular terminals and in the terminal chloroformate groups, has excellent electrical characteristics when used as a material for an electrophotographic photoreceptor, as well as to provide the electrophotographic photoreceptor using this. <P>SOLUTION: The polycarbonate copolymer has the structural units of at least two kinds selected from specific structural units, a viscosity average mol.wt. of 5,000-100,000, 10 ppm or less regarding the amount of the nitrogen introduced into the molecular terminals, and 0.1 μeq/g or less regarding the amount of the chloroformate groups in the molecular terminals. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polycarbonate copolymer, a method for producing the same, and an electrophotographic photoreceptor.
More specifically, less nitrogen is incorporated at the end of the molecule,
The present invention also relates to a polycarbonate copolymer having a small amount of chloroformate groups at the molecular ends, a method for producing the same, and an electrophotographic photoreceptor using the same.

[0002]

2. Description of the Related Art The electrophotographic technology has been widely used and applied not only in the field of copying machines but also in the field of various printers in recent years because of its ability to obtain instant images and high quality images. Photoreceptors, which are the core of electrophotographic technology, have recently been formed as pollution-free inorganic photoconductors such as selenium, arsenic-selenium alloy, cadmium sulfide, and zinc oxide. A photoreceptor using an organic photoconductive material, which has advantages such as easy and easy manufacture, has been developed.

Among organic photoconductors, a so-called laminated type photoconductor in which a charge generation layer and a charge transport layer are laminated has been devised and is the mainstream of research. The multi-layered photoconductor is a high-sensitivity photoconductor obtained by combining a highly efficient charge-generating substance and a charge-transporting substance, and a photoconductor having a wide selection range of materials and high safety, Further, since the coating productivity is high and the cost is comparatively advantageous, the possibility of becoming the mainstream of the photoreceptor is high and the coating has been earnestly developed.

Usually, the charge transport layer is composed of a solid solution of a binder resin and a charge transport material, and various binder resins have been developed in order to obtain good electric characteristics. So far, as binder resins for charge transport layers, vinyl polymers such as polymethacrylate, polystyrene and polyvinyl chloride, and their copolymers, thermoplastic resins such as polycarbonate, polyester, polysulfone, phenoxy, epoxy and silicone resins and thermosetting. Resin is used. Above all, various polycarbonate resins having excellent performance as binder resins have been developed and put into practical use.

For example, bisphenol P type polycarbonate is disclosed in JP-A-50-98332, bisphenol Z type polycarbonate is disclosed in JP-A-59-71057, and bisphenol is disclosed in JP-A-59-184251. A polycarbonate of the copolymerization type of P and bisphenol A is also disclosed in JP-A-5-214.
In Japanese Patent Publication No. 78, a polycarbonate copolymer having a bis (4-hydroxyphenyl) ketone type structure is disclosed as a binder resin. Techniques for reducing impurities contained in the binder resin in order to reduce the influence on the image quality are described in Japanese Patent Application No. 5-229050 and Japanese Patent Application Laid-Open No. 60-97360.
The conditions used in recent copying machines, fax machines, etc. have become more severe and abnormal charging has occurred, resulting in insufficient conditions.

In order to improve the above-mentioned drawbacks, methods have been developed to reduce the amount of nitrogen incorporated at the molecular ends of the binder resin. The nitrogen taken in at the molecular end of the polycarbonate is due to the urethane-bonded nitrogen compound (carbamate) formed by the reaction of the tertiary amine used as a condensation catalyst during the production of the polycarbonate with the polymer end group. As a method for reducing the amount, for example, JP-A-9-106084 describes that the amount of the tertiary amine used is reduced as much as possible within a range that does not reduce the polymerization rate. It is necessary to add a catalyst, and it is not easy to reduce the amount of terminal chloroformate groups at the same time.
In some cases, sufficient electric characteristics could not be obtained.

Further, in JP-A-2-133425 and JP-A-3-27569, the nitrogen bonded to the molecular end is controlled by finely controlling the emulsified state or by significantly shifting the timing of addition of the tertiary amine. Although it is described that it is possible to reduce both the terminal nitrogen and terminal chloroformate groups at the same time, the present situation is that control is not easy and only polycarbonate itself is used, and terminal nitrogen and terminal chloroformate are simultaneously reduced as a binder resin. The effect of the above-mentioned polycarbonate copolymer has not been clarified.

[0008]

DISCLOSURE OF THE INVENTION An object of the present invention is to reduce simultaneously the nitrogen bonded to the molecular end and the terminal chloroformate group in the production of a polycarbonate copolymer, and as a result, an electrophotographic photoreceptor having excellent electrical characteristics. Another object of the present invention is to provide a suitable binder resin and a method for producing the same.

[0009]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies in order to solve the above problems, and as a result, by setting the reaction temperature during polycondensation to 15 ° C. or lower, the catalyst can be used as a polymerization catalyst. It becomes possible to suppress the so-called carbamate reaction in which the tertiary amine reacts with the polymer end group, and the nitrogen compound formed by urethane bonding (terminal nitrogen) is reduced,
At the same time, it was found that the amount of terminal chloroformate group can be reduced because the polycondensation reaction proceeds without reducing the reaction rate.

That is, the gist of the present invention is the following general formula (1)
And has a viscosity average molecular weight of 5,000.
It is 0 to 100,000, the amount of nitrogen incorporated at the molecular end is 10 ppm or less, and the amount of chloroformate group at the molecular end is 0.1 μeq / g or less.

[0011]

[Chemical 9]

Or a single bond, R ¹ and R ² represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a halogenated alkyl group, and Z
Represents a substituted or unsubstituted carbocycle of 4 to 20, and Y ¹ to Y ⁸ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group which may be substituted, Alternatively, it represents a halogenated alkyl group. ) Another gist of the present invention is a carbonate obtained by reacting at least two aromatic diols selected from the aromatic diols represented by the following general formula (3), a carbonate-forming compound, and a monophenol. An oligomer, which is a carbonate oligomer in which the ratio of the terminal chloroformate group concentration to the OH group concentration is 1.1 to 10,
It lies in a method for producing a polycarbonate copolymer, which comprises polycondensation in the presence of an alkali at a temperature of 15 ° C. or lower.

[0013]

[Chemical 10]

[0014] or a single bond, R ^'1 and R' ² represents a hydrogen atom, an alkyl group, an aryl group which may be substituted having 1 to 20 carbon atoms, or, a halogenated alkyl group,
Z represents a 4-20 substituted or unsubstituted carbocycle, Y ¹ to Y ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, or an optionally substituted aryl group. Or a halogenated alkyl group. ) Another gist of the present invention is a) obtained by reacting at least one aromatic diol selected from the aromatic diols represented by the general formula (3), a carbonate-forming compound, and a monophenol. A carbonate oligomer having a ratio of terminal chloroformate group concentration to OH group concentration of 1.1 to 10; and b) different from the aromatic diols used in a), A carbonate oligomer obtained by reacting at least one other aromatic diol selected from the aromatic diols represented by formula (3), a carbonate-forming compound, and a monophenol,
Two carbonate oligomers, in which the ratio of the terminal chloroformate group concentration to the OH group concentration is 1.1 to 10, in the presence of an alkali under a temperature condition of 15 ° C. or less, a polycarbonate copolymer It depends on the manufacturing method.

Another subject matter of the present invention is a coating liquid for an electrophotographic photoreceptor containing the above-mentioned polycarbonate copolymer, and the coating liquid for an electrophotographic photoreceptor is coated on a conductive support. The present invention includes an electrophotographic photoreceptor, and further, an electrophotographic photoreceptor using the above-mentioned polycarbonate copolymer.

[0016]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below.
The polycarbonate copolymer of the present invention is produced by polycondensing an aromatic diol and a compound that forms a carbonate moiety in a copolymer molecule such as phosgene (hereinafter referred to as a carbonate-forming compound). ,
The viscosity average molecular weight is 5,000 to 100,000, the amount of nitrogen incorporated at the molecular end is 10 ppm or less, and the amount of chloroformate group at the molecular end is 0.1 μm.
eq / g or less, and at least 2 selected from structural units represented by the following general formula (1) in the copolymer molecule.
It is characterized by having seed structural units.

[0017]

[Chemical 11]

Or a single bond, R ¹ and R ² represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group which may be substituted, or a halogenated alkyl group;
Represents a substituted or unsubstituted carbocycle of 4 to 20, and Y ¹ to Y ⁸ each independently represent a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an aryl group which may be substituted, Alternatively, it represents a halogenated alkyl group. ) Among the general formula (1), those represented by the following general formula (2) are preferable, and the carbonate copolymer of the present invention is at least 2 selected from the structural units represented by the general formula (2).
It is preferred to have seed structural units.

[0019]

[Chemical 12]

(In the general formula (2), X is an oxygen atom, a cycloalkylidene group having 5 to 10 carbon atoms, or -CR ¹ R ^2-.
And R ¹ and R ² are a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a phenyl group, and Y ¹ to Y ⁸ are a hydrogen atom, a chlorine atom, a bromine atom, It is a methyl group, an ethyl group, an n-propyl group, an isopropyl group, a sec-butyl group, an n-butyl group, an isobutyl group, a tert-butyl group, or a phenyl group. )

In the general formula (1) or (2), R ¹ and R ² are more preferably hydrogen atoms or methyl groups, and Y ¹ to Y ⁸ are more preferably methyl groups or phenyl groups.

Specific examples of the structural unit represented by the general formula (1) include, for example, [1-1] to [1-12] shown below.
And the like. The polycarbonate copolymer of the present invention is particularly [1-1], [1-2], [1-
3], [1-4], and [1-5] having one or more kinds of structural units are preferable, and further, [1-1] to
Those having two or more kinds of structural units selected from [1-5] are preferable. A particularly preferred structural unit is [1-
1], [1-2] and [1-5].

[0023]

[Chemical 13]

The polycarbonate copolymer of the present invention has at least two kinds of the above-mentioned structural units, and the content ratio of each structural unit is not particularly limited, but the characteristics aimed at by the present invention are exhibited. Therefore, it is preferable that the content of the most structural unit is 30 to 95% by weight.
It is more preferably 0 to 90% by weight. In addition, [1
-1] or [1-2] structural units, the content of these structural units is preferably 10 to 90% by weight. Further, when both of the structural units [1-1] and [1-2] are included, it is preferable that the structural units are contained in the range of 10 to 90% by weight, respectively, and further, [1-1] is 40% by weight.
-80 wt% and [1-2] in the range of 20-60 wt% are preferable.

The polycarbonate copolymer of the present invention is a polyester, polyarylate, polyamide, polyacetal, polyurethane,
Other structural units such as polyimide, polyether, polyketone, polyvinyl polymer and polysiloxane may be introduced. When another structural unit is introduced, the polycarbonate structural unit represented by the general formula (1) is preferably 70% or more, and more preferably 80% or more of all structural units. Examples of the other structural unit include structural units represented by the following [2-1] to [2-4].

[0026]

[Chemical 14]

The polycarbonate polymer of the present invention preferably has a viscosity average molecular weight of 5,000 to 100,000 or less, more preferably 10,000 to 100,
000 or less, and particularly preferably 20,000 to 50,000 or less. If the viscosity average molecular weight is less than 5,000, the mechanical strength of the resin is significantly reduced, and it cannot be practically used as a molding material. If it is 50,000 or more, the fluidity at the time of injection molding may be too high, which may make molding difficult.
When it is 50,000 or more, it may be difficult to apply the cast film to an appropriate thickness to prepare the film.

The aromatic diols used as a raw material for the polycarbonate of the present invention are compounds having two phenolic hydroxyl groups in the molecule, and form the above-mentioned structural unit by polycondensation with a carbonate-forming compound. And is specifically represented by the following general formula (3).

[0029]

[Chemical 15] Or a single bond, R ′ ¹ and R ′ ² represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a halogenated alkyl group, and Z is 4 to 20.
Represents a substituted or unsubstituted carbocycle, Y ¹ to Y ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or
Indicates a halogenated alkyl group. In the present invention, two or more kinds of aromatic diols represented by the general formula (3) are used in combination. In the general formula (3),
X is preferably an oxygen atom, a cycloalkylidene group having 5 to 10 carbon atoms, or, -CR ¹ R ² - is. R ¹ and R
² is preferably a hydrogen atom, a methyl group, an ethyl group or n-
It is a propyl group, an isopropyl group, or a phenyl group, and more preferably a hydrogen atom or a methyl group. Y
¹ to Y ⁸ are preferably hydrogen atom, chlorine atom, bromine atom, methyl group, ethyl group, n-propyl group, isopropyl group, sec-butyl group, n-butyl group, isobutyl group, tert-butyl group, or , A phenyl group, and more preferably a methyl group or a phenyl group.

Particularly suitable aromatic diols include 2,2
-Bis (4-hydroxyphenyl) propane (bisphenol A), 2,2-bis (3,5-dimethyl-4-hydroxyphenyl) propane, 1,1-bis (4-hydroxyphenyl) cyclohexane (bisphenol Z), And 1,1-bis (4-hydroxyphenyl)-
Includes 3,3,5-trimethylcyclohexane.

The carbonate-forming compound used as a raw material for the polycarbonate of the present invention is not particularly limited as long as it reacts with an aromatic diol to form a carbonate bond, and various compounds such as phosgene and dimethyl carbonate are used. Can be adopted. A compound represented by the following general formula (4) is preferable, and phosgene is more preferable.

[0032]

[Chemical 16]

(In the general formula (4), R ³ and R ⁴ each independently represent a chlorine atom or an alkoxy group having 1 to 6 carbon atoms.)

In the present invention, any branching agent can also be used as a raw material for polycarbonate. The branching agent used can be selected from various compounds having three or more functional groups. Suitable branching agents include
Examples thereof include compounds having 3 or more phenolic hydroxyl groups, such as 2,4-bis (4-hydroxyphenylisopropyl) phenol and 2,6-
Bis (2-hydroxy-5-methylbenzyl) -4-methylphenol, 2- (4-hydroxyphenyl) -2
-(2,4-dihydroxyphenyl) propane and 1,
4-bis (4,4'-dihydroxytriphenylmethyl) benzene may be mentioned. Further, 2,4-dihydroxybenzoic acid, trimesic acid, and cyanuric chloride, which are compounds having three functional groups, can also be used. Among them, those having three or more phenolic hydroxy groups are preferable. Although the amount of the branching agent used varies depending on the desired degree of branching, it is usually 0.
It is used in an amount of 05-2 mol%.

In the present invention, the monophenols used as the molecular weight regulator include various phenols, for example, ordinary phenol, and C1-20 carbon atoms such as pt-butylphenol and p-cresol. Alkylphenol, and p-chlorophenol and 2,
Included are halogenated phenols such as 4,6-tribromophenol. Among them, phenol, p-isopropylphenol, p-dodecylphenol, pt
Phenols in which the para-position is substituted with an alkyl group having 1 to 20 carbon atoms such as butylphenol are more preferable. The amount of the monophenols used varies depending on the molecular weight of the desired condensate, but it is usually used in an amount of 0.5 to 10% by weight based on the starting aromatic diol.

The method for producing the polycarbonate copolymer of the present invention is usually 1) a method of reacting phosgene as a carbonate-forming compound with an aromatic diol under interfacial polycondensation conditions or solution polymerization conditions, or ) Diphenyl carbonate can be produced by a method of reacting phosgene and phenol, and the reaction can be performed by a method of reacting this with an aromatic diol under melt condensation conditions. In particular, the method of 1) above, Among them, a typical method is preferable, in which an aqueous solution of a metal salt of an aromatic diol and phosgene are reacted in an emulsified state in the presence of an organic solvent to obtain a carbonate oligomer. The above method 1) will be described in detail below.

In the above method, the aromatic diol forms an aqueous phase with water and a water-soluble metal hydroxide. As the metal hydroxide, an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide is usually used. In the aqueous phase, aromatic diols react with the above hydroxides to form water-soluble metal salts. In this case, the molar ratio of the aromatic diols to the alkali metal hydroxide in the aqueous phase is 1: 1.8 to 1:
3.5 is preferable, and 1: 2.0 to 1: 3.2 is more preferable. A small amount of a reducing agent such as hydrosulfite may be added to the aqueous phase.

As the organic solvent to be used, at the reaction temperature and the reaction pressure, phosgene and a reaction product such as a carbonate oligomer and a polycarbonate are dissolved, but water is not dissolved (in the sense that a solution is not formed with water). Contains an inert organic solvent.

Typical inert organic solvents include aliphatic hydrocarbons such as hexane and n-heptane, methylene chloride, chloroform, carbon tetrachloride, dichloroethane, trichloroethane, tetrachloroethane, dichloropropane and 1,2-dichloroethylene. Such as chlorinated aliphatic hydrocarbons, benzene, aromatic hydrocarbons such as toluene and xylene, chlorobenzene, chlorinated aromatic hydrocarbons such as o-dichlorobenzene and chlorotoluene, and other substitutions such as nitrobenzene and acetophenone Aromatic hydrocarbons are included.

Of these, chlorinated hydrocarbons such as methylene chloride or chlorobenzene are preferably used.
These inert organic solvents can be used alone or as a mixture with other solvents.

Phosgene is used in liquid or gaseous form. From the viewpoint of temperature control, phosgene is preferably liquid, and a reaction pressure capable of maintaining liquid at the reaction temperature is selected. The preferred amount of phosgene used is reaction conditions,
Although it is affected by the reaction temperature and the concentration of the aromatic diol metal salt in the aqueous phase, the number of moles of phosgene per mole of the aromatic diol is usually 1 to 2, preferably 1 to 1.5. . If this ratio is too large, the loss of phosgene increases, and the formation of a condensate of the terminator is recognized, which is not preferable. On the other hand, if it is too small,
It is not preferable because the CO group is insufficient and proper molecular weight extension is not performed.

In the present invention, when the two-phase interfacial condensation method is adopted, it is particularly preferable that the organic phase and the aqueous phase are brought into contact with each other prior to the contact with phosgene to form an emulsion. In order to form an emulsion, in addition to a stirrer having a normal stirring blade, a homogenizer, a homomixer, a colloid mill, a flow jet mixer, a dynamic mixer such as an ultrasonic emulsifier, and a mixer such as a static mixer. Is preferably used. Emulsions usually have a droplet size of 0.01 to 10 μm and have emulsion stability.

The emulsified state is usually the Weber number or P /
It can be expressed by q (additional power value per unit volume). The Weber number is preferably 10,000 or more, more preferably 20,000 or more, and most preferably 35,
It is more than 000. The upper limit is 1,000,0.
A value of about 00 or less is sufficient. Further, P / q is preferably 200 kg · m / liter or more, more preferably 500 kg · m / liter or more, and most preferably 1,000 kg · m / liter or more.

The contact between the emulsion and phosgene is preferably carried out under mixing conditions weaker than the above-mentioned emulsification conditions in order to suppress the dissolution of phosgene in the organic phase, and the Weber number is less than 10,000, preferably It is less than 5,000, more preferably less than 2,000. Further, P / q is less than 200 kg · m / liter, preferably 100
less than kg · m / liter, more preferably 50 kg ·
It is less than m / liter. The contact with phosgene can be achieved by introducing phosgene into a tubular reactor or a tank reactor.

The molecular weight of the polycarbonate copolymer is determined by the amount of the molecular weight modifier such as monophenol added.
However, from the viewpoint of the controllability of the molecular weight, the addition timing is preferably immediately after the consumption of the carbonate-forming compound ends and before the extension of the molecular weight begins. When monophenols are added in the presence of a carbonate-forming compound, a large amount of condensates of monophenols (diphenyl carbonates) are produced, and it is difficult to obtain a polycarbonate resin having a target molecular weight, which is a binder resin for electrophotographic photoreceptors. When used as, it is not preferable because the electric characteristics are deteriorated. On the other hand, if the addition of monophenols is extremely delayed, it becomes difficult to control the molecular weight, and the product has a unique shoulder on the low molecular weight side of the molecular weight distribution, which may cause sagging during molding. There are many adverse effects and it is not very desirable.

In a preferred embodiment of the method for producing the polycarbonate copolymer of the present invention, a carbonate oligomer having a viscosity average molecular weight of 500 to 10,000 is once produced from an aromatic diol compound, a carbonate-forming compound and phenols. Is further polycondensed to obtain a polycarbonate copolymer.

To introduce at least two kinds of aromatic diol structural units into the polycarbonate copolymer, 1)
As a method of using two or more kinds of aromatic diols as raw materials in the step of producing a carbonate oligomer,
A carbonate oligomer obtained by reacting at least two kinds of aromatic diols selected from the aromatic diols represented by the above general formula (3), a carbonate-forming compound, and a monophenol, wherein There is a method for producing a polycarbonate copolymer by polycondensing a carbonate oligomer having a terminal chloroformate group concentration ratio of 1.1 to 10 in the presence of an alkali at a temperature condition of 15 ° C. or lower.

As 2), two or more carbonate oligomers are produced using different aromatic diols,
A method of polycondensing these carbonate oligomers,
That is, a) a carbonate oligomer obtained by reacting at least one aromatic diol selected from the aromatic diols represented by the general formula (3), a carbonate-forming compound, and a monophenol, The ratio of the terminal chloroformate group concentration to the OH group concentration is 1.
1 to 10 carbonate oligomer, and b) at least one aromatic diol different from the aromatic diols used in a) and selected from the aromatic diols represented by the above general formula (3). A carbonate-forming compound, and a carbonate oligomer obtained by reacting a monophenol with a ratio of the terminal chloroformate group concentration to the OH group concentration of 1.1 to 10. , A method of producing a polycarbonate copolymer by carrying out polycondensation in the presence of an alkali under a temperature condition of 15 ° C. or lower.

The oligomerization reaction can be carried out in the presence of a condensation catalyst. The addition is preferably performed after phosgene is consumed, and the condensation catalyst can be arbitrarily selected from many condensation polymerization catalysts used in the two-phase interfacial condensation method. Among them, trialkylamine, N
-Ethylpyrrolidone, N-ethylpiperidine, N-ethylmorpholine, N-isopropylpiperidine and N-isopropylmorpholine are suitable, especially triethylamine and N-ethylpiperidine.

The reaction temperature for obtaining the oligomer is 80 ° C.
Below, preferably below 60 ℃, more preferably 10 ℃
The reaction time is usually 0.5 minutes to 10 hours, preferably 1 minute to 2 hours, although it depends on the reaction temperature. If the reaction temperature is too high, the side reaction cannot be controlled and the phosgene basic unit is deteriorated. On the other hand, if it is too low, it is a preferable situation in terms of reaction control, but the refrigeration load increases and the cost increases accordingly, which is not preferable.

The concentration of the oligomer in the organic phase may be within the range in which the obtained oligomer is soluble, and specifically 10
It is about 40% by weight. The ratio of the organic phase is preferably 0.2 to 1.0 in volume ratio with respect to the aqueous solution of the alkali metal hydroxide of the aromatic diol, that is, the aqueous phase. The viscosity average molecular weight of the oligomer obtained under such condensation conditions is usually about 500 to 10,000, preferably 1.00.
It is 0 to 5,000.

The carbonate oligomer thus obtained is converted into a high molecular weight polycarbonate copolymer under polycondensation conditions according to a conventional method. In a preferred embodiment, the organic phase in which the oligomer is dissolved is separated from the aqueous phase, and if necessary, the above-mentioned inert organic solvent is added to adjust the concentration of the oligomer. That is, the amount of the solvent is adjusted so that the concentration of the polycarbonate in the organic phase obtained by polycondensation is 5 to 30% by weight. Thereafter, an aqueous phase containing water and an alkali metal hydroxide is newly added, and a condensation catalyst is preferably added to adjust the polycondensation conditions, and the desired polycondensation is completed according to the interfacial polycondensation method. The volume ratio of the organic phase and the aqueous phase during the polycondensation is the organic phase:
Aqueous phase = 1: 0.2 to 1 is preferable.

In the polycondensation reaction of the carbonate oligomer, the ratio of the terminal chloroformate group concentration to the OH group concentration of the oligomer at the start of polycondensation (hereinafter referred to as CF / OH) is preferably 1.1 to 10. 0.5-5 is more preferable. If CF / OH is smaller than 1.1, polycondensation will be incomplete and a large amount of chloroformate will remain, and the target molecular weight will not be reached. On the other hand, when CF / OH is 10 or more, although the target molecular weight is reached, the amount of nitrogen taken in at the terminal of the molecule is increased and the electrical characteristics deteriorate when used as an electrophotographic photoreceptor, which is not preferable.

The oligomer to be subjected to polycondensation is a polycarbonate oligomer obtained by reacting an aromatic diol and a carbonate-forming compound with monophenols as a molecular weight modifier. Even if the oligomer does not satisfy the above conditions. Sometimes it can be achieved. For example, when the CF / OH of the obtained oligomer is 10 or more, an aromatic diol that is a raw material of the oligomer is added at the start of polycondensation to increase the apparent OH value to raise the CF / OH to 1.1 to.
It can also be achieved by adding an alkali after 10 and polycondensation, including this case. That is, by defining the CF / OH ratio at the start of polycondensation, the carbamate reaction is suppressed and the nitrogen incorporation amount at the molecular end can be reduced.

The polycondensation reaction of the carbonate oligomer can be carried out in the presence of the same condensation catalyst as in the oligomerization reaction. According to the invention, the amount of condensation catalyst used is from 0.05 to 0.5 mol%, preferably from 0.05 to 0.2 mol%, based on the aromatic diol. 0.05m
If it is less than ol%, the polycondensation reaction will be remarkably slowed, the contact time with the alkali will increase, and the amount of unreacted aromatic diol will increase. If it exceeds 0.5 mol%, the polycondensation reaction will be sped up, but a great deal of labor is required for extraction and removal of the condensation catalyst in the washing step, which is not preferable.

After completion of the polycondensation, until the remaining chloroformate group (CF group) becomes 0.1 μeq / g or less,
It may be washed with an alkali such as sodium hydroxide. When the CF group concentration exceeds 0.1 μeq / g, when used in an electrophotographic photoreceptor, for example, the electrical characteristics deteriorate, which is not preferable. After that, the organic phase is washed until the electrolyte is exhausted, and finally the inert organic solvent is appropriately removed from the organic phase to separate the polycarbonate.

The amount of nitrogen incorporated into the molecular chain of the polycarbonate copolymer of the present invention obtained as described above is usually 10 ppm or less and the amount of terminal chloroformate group is 0.1 μeq / g or less. . When the amount of nitrogen incorporated in the molecular chain or the amount of terminal chloroformate group is increased, the electrical characteristics are deteriorated when used in an electrophotographic photoreceptor or the like, which is not preferable.

The present inventors have examined a method of reducing the nitrogen taken in at the molecular end to 10 ppm or less and the amount of terminal chloroformate group to 0.1 μeq / g or less.
Surprisingly, by setting the reaction temperature at the time of polycondensation to 15 ° C. or lower, preferably 0 ° C. to 10 ° C., the carbamate reaction can be significantly suppressed, and the nitrogen compound (terminal nitrogen) formed by the urethane bond is formed. It was found that the amount of the terminal chloroformate group can be reduced because the condensation reaction proceeds at the same time without decreasing the reaction rate. If the reaction temperature at the time of polycondensation exceeds 15 ° C., the carbamate reaction proceeds extremely, and the nitrogen taken in at the molecular end exceeds 10 ppm, which is not preferable.

The polycarbonate copolymer of the present invention can be used, for example, in an electrophotographic photoreceptor. When the polycarbonate is used in the electrophotographic photoreceptor, it is contained in the photosensitive layer provided on the conductive support. As one specific example of the constitution of the photosensitive layer, a charge generating layer containing a charge generating substance as a main component and a charge transporting layer containing a charge transporting substance and a binder resin as a main component are provided on a conductive support in this order. As a second example, a laminated type photoconductor in which a charge transport layer containing a charge transport material and a binder resin as main components and a charge generation layer containing a charge generating substance as a main component are provided on a conductive support. An inverse two-layer type photoconductor laminated in this order, and as a third example, a dispersion type photoconductor in which a charge generating substance is dispersed in a layer containing a charge transporting substance and a binder resin on a conductive support. A body-like configuration is an example of a basic shape.

The polycarbonate copolymer of the present invention can be used as a binder resin for a photosensitive layer, but is mainly suitable as a binder resin for a charge transport layer in a laminated type photoreceptor or a binder resin for a photosensitive layer of a dispersion type photoreceptor. Is. Among them, it is most suitable as the binder resin of the charge transport layer in the laminated type photoreceptor in which the charge generation layer and the charge transport layer are laminated in this order on the conductive support.

As the conductive support, aluminum,
Metals such as copper, zinc and iron, and alloys thereof, or those obtained by vapor-depositing metal on a resin are used, and among these, aluminum or its alloy is preferably used.

Examples of the charge generating substance used in the charge generating layer include selenium and its alloys, cadmium sulfide, other inorganic photoconductive materials, phthalocyanine pigments, azo pigments, quinacridone pigments, indigo pigments, perylene pigments and polycyclic quinones. Various photoconductive materials such as organic pigments such as pigments, antanthrone pigments and benzimidazole pigments can be used, and organic pigments, particularly phthalocyanine pigments and azo pigments are preferable.

These charge generating substances include polyester resin, polyvinyl acetate, polyacrylic acid ester,
Polymethacrylic acid ester, polyester, polycarbonate, polyvinyl acetoacetal, polyvinyl propional, polyvinyl butyral, phenoxy resin,
It is used in a form bound with various binder resins such as epoxy resin, urethane resin, cellulose ester, and cellulose ether, or in a form vapor-deposited on a conductive support.

When the binder resin is used, it is used in an amount of 30 to 500 parts by weight of the charge generating substance with respect to 100 parts by weight of the binder resin, and the film thickness thereof is usually 0.1 to 1 μm, and particularly 0.1. 15-0.6 μm is suitable.

Examples of the charge-transporting substance for the charge-transporting layer include electron-withdrawing substances such as 2,4,7-trinitrofluorenone and tetracyanoquinodimethane, carbazole, indole, imidazole, oxazole and pyrazole.
Heterocyclic compounds such as oxadiazole, pyrazoline, and thiadiazole, aniline derivatives, hydrazone compounds, aromatic amine derivatives, stilbene derivatives or electron-donating substances such as polymers having groups consisting of these compounds in the main chain or side chain Can be mentioned.

Particularly, a low molecular weight compound which is not a polymer is preferable. A binder resin is blended with these charge transport materials. The charge transport layer may optionally contain various additives such as an antioxidant and a sensitizer. The thickness of the charge transport layer is 10 to 50 μm, preferably 10 to 40 μm.
It is preferably used with a thickness of m.

In the case of the dispersion type, the above-mentioned polycarbonate copolymer of the present invention is used as the binder resin, and the resin 1
The charge transport material is preferably used in the range of 30 to 150 parts by weight based on 00 parts by weight. The film thickness is usually 5
-50 μm, preferably 10-30 μm is suitable.
If necessary, various additives such as antioxidants and sensitizers may be included.

In the case of the dispersion type photosensitive layer, the above-mentioned charge generating substance is dispersed in the charge transporting medium composed of the binder resin and the charge transporting substance having the above blending ratio. In that case, it is necessary that the particle size of the charge generating substance is sufficiently small, and preferably 1 μm or less, more preferably 0.5 μm.
Used below. If the amount of the charge generating substance dispersed in the photosensitive layer is too small, sufficient sensitivity cannot be obtained, and if the amount is too large, there are adverse effects such as a decrease in charging property and a decrease in sensitivity. For example, preferably 0.5 to 50% by weight. %, More preferably 1 to 20% by weight.

The thickness of the photosensitive layer is usually 5 to 50 μm, more preferably 10 to 45 μm. Also in this case, known plasticizers for improving film-forming properties, flexibility, mechanical strength, etc., additives for suppressing residual potential, dispersion aids for improving dispersion stability, and coating properties. Leveling agents to improve the surface-active agents such as silicone oil,
Fluorine-based oil and other additives may be added.

To provide the photosensitive layer or the charge transport layer on the conductive support, a coating solution is usually prepared by mixing the polycarbonate copolymer of the present invention, the charge transport material and other additives in a suitable solvent. And is preferably applied by dip coating on a support and then dried.

Further, these photoreceptors may be provided with an overcoat layer mainly composed of, for example, a thermoplastic or thermosetting polymer, which is publicly known as the outermost surface layer. These photosensitive layers are formed on the conductive support by known methods such as roll coating, bar coating, dip coating, spray coating and multi-nozzle coating. As the conductive support provided with the photosensitive layer, aluminum, stainless steel, a metal material such as nickel, a polyester film provided with a conductive layer such as aluminum, copper, palladium, tin oxide, indium oxide on the surface,
An insulating support such as paper or glass is used.

A publicly known barrier layer which is usually used may be provided between the conductive support and the photosensitive layer. Examples of the barrier layer include an anodized aluminum film, an inorganic layer such as aluminum oxide and aluminum hydroxide, polyvinyl alcohol, casein, polyvinylpyrrolidone, polyacrylic acid, celluloses, gelatin,
Organic layers of starch, polyurethane, polyimide, polyamide, etc. are used. The thickness of the barrier layer is 0.1-2
The range of 0 μm is preferable, and the range of 0.1 to 10 μm is most effective. As a method for forming each layer, a known method such as sequentially coating a coating solution obtained by dissolving or dispersing a substance contained in the layer in a solvent can be applied.

[0073]

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to the following examples unless it exceeds the gist. Further, each measured value in the examples is obtained by the following method. (1) Viscosity average molecular weight (Mv) It was calculated using the following formula from ηSP measured at 20 ° C. using a 0.6 g / dl methylene chloride solution of an oligomer or a polymer.

[Equation 1] ηSP / C = [η] (1 + 0.28ηSP) ηSP = 1.23 × 10 ⁻⁴ Mv ^0.83

(2) Concentration of oligomeric terminal chloroformate group (CF group) After diluting the oligomer solution with methylene chloride, aniline and pure water were added, and titrated with NaOH of normality using phenolphthalein as an indicator. It was (3) Oligomer terminal phenolic OH group concentration (OH
Group) After diluting the oligomer solution with methylene chloride, add titanium tetrachloride and acetic acid solution to develop color and spectrophotometer (Hitachi Ltd.)
The absorbance at a wavelength of 546 nm was measured using a UV-160 type manufactured by K.K. Separately, the extinction coefficient was determined using the methylene chloride solution of the aromatic diol used in the production of the oligomer, and the amount of terminal phenolic OH groups of the oligomer was quantified.

(4) Concentration of chloroformate group at the molecular end of polycarbonate (a small amount of CF) About 1 g of polycarbonate was precisely weighed and methylene chloride was added to 20 m.
1 was added and dissolved. To this, 2 ml of a 1 wt% methylene chloride solution of 4- (p-nitrobenzyl) pyridine was added to develop color, and the absorbance at a wavelength of 440 nm was measured using a spectrophotometer (manufactured by Hitachi Ltd., Model 330). Separately, the extinction coefficient was determined using a methylene chloride solution of phenylchloroformate, and the amount of chloroformate groups in the sample was quantified.

(5) Polycarbonate Amount of nitrogen incorporated at the molecular end of polycarbonate About 20 mg of polycarbonate was used, and Mitsubishi Chemical Corporation
Manufactured by Nitrogen Analyzer (TN-10).

[Example 1] 2,2-bis (4-hydroxyphenyl) propane (hereinafter referred to as "BPA") 11.2
kg / hour, 2,2-bis (4-hydroxy-3methylphenyl) propane (hereinafter referred to as "BPC") 4.8 kg
/ H, sodium hydroxide 5.59 kg / h, and water 1
01.1 kg / hour for 0.018 hydrosulfite
In the presence of kg / h, the aqueous phase was dissolved at 35 ° C and then cooled to 25 ° C, and methylene chloride 6 cooled to 5 ° C.
0.5kg / h organic phase, 6mm inner diameter, 8m outer diameter
m stainless steel pipe, mixed in the same pipe, and further homomixer (manufactured by Tokushu Kika Co., Ltd., product name TK
The emulsion was prepared by emulsification using Homomic Line Flow LF-500 type).

BPA + BPC thus obtained
An aqueous solution of sodium salt (water phase) and an emulsion of methylene chloride (organic phase) are branched from a homomixer with an inner diameter of 6 m.
m, the outer diameter is 8 mm, and the inner diameter is 6
In a Teflon (registered trademark) pipe reactor having a length of mm and a length of 34 m, liquefied phosgene 6.98 kg / hour supplied from a pipe cooled separately to 0 ° C. was introduced.

The above emulsion was subjected to phosgenation and oligomerization reaction while flowing through phosgene and a pipe reactor at a linear velocity of 1.7 m / sec for 20 seconds. At this time, the reaction temperature was adjusted to 60 ° C., and external cooling was performed to 35 ° C. before entering the next oligomerization tank. The oligomerized emulsion thus obtained from the pipe reactor is further introduced into a reaction tank equipped with a stirrer and having an internal volume of 50 liters, and the mixture is stirred at 30 ° C. under a nitrogen gas atmosphere to be oligomerized. After completely consuming the unreacted Na salt of the aromatic diol, the aqueous phase and the organic phase were separated by standing to obtain a solution of the oligomer in methylene chloride. In the case of oligomerization, 2 of triethylamine
A weight% aqueous solution of 0.28 kg / hr and a 24 wt% methylene chloride solution of pt-butylphenol of 1.0
Each was added to the oligomerization tank at 2 kg / hr. At this time, the oligomer had a viscosity average molecular weight (Mv) of 2,800, a terminal chloroformate group concentration of 0.44N, and a terminal phenolic OH group concentration of 0.27N.

50 kg of the methylene chloride solution of the above oligomer was charged into a reaction tank with an internal volume of 150 L and equipped with a Faudler blade, and 25 kg of methylene chloride for dilution was added thereto.
Was added, and further 25 wt% sodium hydroxide aqueous solution 4.37 kg, water 6 kg, and triethylamine 2.2.
g was added, the mixture was stirred at 10 ° C. under a nitrogen gas atmosphere, and a polycondensation reaction was performed for 120 minutes to obtain a polycarbonate copolymer. To this reaction liquid, 30 kg of methylene chloride and 7 kg of water
Was added and stirred for 20 minutes, then the stirring was stopped and the aqueous phase and the organic phase were separated. To the separated organic phase, 0.1N hydrochloric acid 20
After adding kg, the mixture was stirred for 15 minutes to extract triethylamine and a small amount of the remaining alkali component, and then the stirring was stopped and the aqueous phase and the organic phase were separated. Further, 20 kg of pure water was added to the separated organic phase, and after stirring for 15 minutes, the stirring was stopped and the aqueous phase and the organic phase were separated. This operation was repeated (3 times) until chlorine ions in the extracted waste water were not detected.

The purified polycarbonate solution thus obtained was faded into warm water to obtain polymer powder and dried in a ventilating dryer at 120 ° C. for 48 hours under a nitrogen atmosphere. The obtained polycarbonate copolymer (hereinafter referred to as "C-1") has a viscosity average molecular weight (Mv) of 30,000, a molecular terminal chloroformate group concentration of 0.001 µeq / g, and incorporation into the molecular terminal. The amount of nitrogen produced was 4.1 ppm.

Example 2 BPC 8.0 kg / hour, 1,
1-bis (4-hydroxyphenyl) 1-phenylethane (hereinafter referred to as "BPP") 8.0 kg / hr, sodium hydroxide 5.18 kg / hr, and water 101.1 kg / hr.
An aqueous phase obtained by dissolving time at 35 ° C. in the presence of 0.018 kg / hour of hydrosulfite and then cooling to 25 ° C.
Further, 60.5 kg / hr of methylene chloride cooled to 5 ° C./hour was fed to a stainless steel pipe having an inner diameter of 6 mm and an outer diameter of 8 mm, respectively, and mixed in the pipe, and further, a homomixer (made by Tokushu Kika Co., Ltd.). , Product name TK homomic line flow LF-500 type) was used to prepare an emulsion.

BPC + BPP obtained in this way
An aqueous solution of sodium salt (water phase) and an emulsion of methylene chloride (organic phase) are branched from a homomixer with an inner diameter of 6 m.
m, the outer diameter is 8 mm, and the inner diameter is 6
In a Teflon pipe reactor having a length of mm and a length of 34 m, 6.01 kg / hour of liquefied phosgene supplied from a pipe separately cooled here at 0 ° C. was brought into contact.

The above emulsion was subjected to phosgenation and oligomerization reaction while flowing through phosgene and a pipe reactor at a linear velocity of 1.7 m / sec for 20 seconds. At this time, the reaction temperature was adjusted to 60 ° C., and external cooling was performed to 35 ° C. before entering the next oligomerization tank. The oligomerized emulsion thus obtained from the pipe reactor is further introduced into a reaction tank equipped with a stirrer and having an internal volume of 50 liters, and the mixture is stirred at 30 ° C. under a nitrogen gas atmosphere to be oligomerized. After completely consuming the unreacted BPC + BPP Na salt present therein, the aqueous phase and the organic phase were separated by standing to obtain a methylene chloride solution of the oligomer. In the case of oligomerization, 2 of triethylamine
A weight% aqueous solution of 0.28 kg / hr and a 24 wt% methylene chloride solution of pt-butylphenol of 0.8%
Each was added to the oligomerization tank at 8 kg / hr. At this time, the oligomer had a viscosity average molecular weight (Mv) of 2500, a terminal chloroformate group concentration of 0.41N, and a terminal phenolic OH group concentration of 0.12N.

50 kg of a methylene chloride solution of the above oligomer was charged into a reaction tank with an internal volume of 150 L and equipped with a Faudler blade, and 25 kg of methylene chloride for dilution was added thereto.
Was added, and further, 4.88 kg of a 25 wt% sodium hydroxide aqueous solution, 6 kg of water, and triethylamine 2.2.
g was added, the mixture was stirred at 10 ° C. under a nitrogen gas atmosphere, and a polycondensation reaction was performed for 120 minutes to obtain a polycarbonate copolymer. To this reaction liquid, 30 kg of methylene chloride and 7 kg of water
Was added and stirred for 20 minutes, then the stirring was stopped and the aqueous phase and the organic phase were separated. To the separated organic phase, 0.1N hydrochloric acid 20
After adding kg, the mixture was stirred for 15 minutes to extract triethylamine and a small amount of the remaining alkali component, and then the stirring was stopped and the aqueous phase and the organic phase were separated. Further, 20 kg of pure water was added to the separated organic phase, and after stirring for 15 minutes, the stirring was stopped and the aqueous phase and the organic phase were separated. This operation was repeated (3 times) until chlorine ions in the extracted waste water were not detected.

The obtained purified polycarbonate solution was faded into warm water to obtain polymer powder and dried in a ventilating dryer under a nitrogen atmosphere at 120 ° C. for 48 hours. The obtained polycarbonate copolymer (hereinafter referred to as “C-2”) has a viscosity average molecular weight (Mv) of 30,300, a molecular terminal chloroformate group concentration of 0.001 μeq / g, and is incorporated into the molecular terminal. The amount of nitrogen was 4.7 ppm.

[Example 3] BPC 16.0 kg / hr, sodium hydroxide 5.15 kg / hr, and water 101.1
kg / hr was dissolved in the presence of 0.018 kg / hr of hydrosulfite at 35 ° C. and then cooled to 25 ° C. in an aqueous phase, and 60.5 kg of methylene chloride cooled to 5 ° C.
/ Hour of the organic phase is supplied to a stainless steel pipe each having an inner diameter of 6 mm and an outer diameter of 8 mm, mixed in the same pipe, and further homomixer (manufactured by Tokushu Kika Co., Ltd., product name TK homomic line flow LF). -500 type) and emulsified to prepare an emulsion.

The emulsion of the aqueous solution of sodium salt of BPC (aqueous phase) and methylene chloride (organic phase) thus obtained was branched from a homomixer and the inner diameter was 6 mm and the outer diameter was 8
In a Teflon pipe reactor having an inner diameter of 6 mm and a length of 34 m, which is connected to the pipe, the liquefied phosgene 7.05 kg / hour supplied from a separately cooled pipe cooled to 0 ° C. is brought into contact therewith. .

The emulsion was subjected to phosgenation and oligomerization reaction while flowing through phosgene and a pipe reactor at a linear velocity of 1.7 m / sec for 20 seconds. At this time, the reaction temperature was adjusted to 60 ° C., and external cooling was performed to 35 ° C. before entering the next oligomerization tank. The oligomerized emulsion thus obtained from the pipe reactor is further introduced into a reaction tank equipped with a stirrer and having an internal volume of 50 liters, and the mixture is stirred at 30 ° C. under a nitrogen gas atmosphere to be oligomerized. After completely consuming the unreacted Na salt of BPC therein, the aqueous phase and the organic phase were separated by standing to obtain a methylene chloride solution of the oligomer. 2% by weight of triethylamine during oligomerization
0.28 kg / hour of aqueous solution and 0.94 kg of 24 wt% methylene chloride solution of pt-butylphenol.
/ H each was added to the oligomerization tank. At this time, the oligomer (hereinafter referred to as “BPC oligomer”) had a viscosity average molecular weight (Mv) of 1800, a terminal chloroformate group concentration of 0.54 N, and a terminal phenolic OH group concentration of 0.36 N.

Separately, BPP is used instead of BPC in the same device.
16.0 kg / hour, sodium hydroxide 4.86 kg
/ H and 101.1 kg / h of water were dissolved at 35 ° C in the presence of 0.018 kg / h of hydrosulfite, then the aqueous phase was cooled to 25 ° C and methylene chloride 60 cooled to 5 ° C. 0.5 kg / hr of organic phase, each with an inner diameter of 6
mm, an outer diameter of 8 mm, and supplied to a stainless steel pipe, mixed in the pipe, and further homomixer (manufactured by Tokushu Kika Co., Ltd., product name TK Homomic Line Flow LF-500).
Emulsification was carried out using a mold) to prepare an emulsion.

The thus-obtained aqueous solution of sodium salt of BPP (aqueous phase) and an emulsion of methylene chloride (organic phase) are branched from a homomixer and the inner diameter is 6 mm and the outer diameter is 8
In a Teflon pipe reactor with an inner diameter of 6 mm and a length of 34 m, which is connected to the pipe, the liquefied phosgene is supplied in a contact with a pipe cooled at 0 ° C., which is separately introduced here, at a temperature of 5.63 kg / hr. .

The emulsion was subjected to phosgenation and oligomerization while flowing through phosgene and a pipe reactor at a linear velocity of 1.7 m / sec for 20 seconds. At this time, the reaction temperature was adjusted to 60 ° C., and external cooling was performed to 35 ° C. before entering the next oligomerization tank. The oligomerized emulsion thus obtained from the pipe reactor is further introduced into a reaction tank equipped with a stirrer and having an internal volume of 50 liters, and the mixture is stirred at 30 ° C. under a nitrogen gas atmosphere to be oligomerized. After completely consuming the unreacted Na salt of BPP therein, the aqueous phase and the organic phase were separated by standing to obtain a methylene chloride solution of the oligomer. 2% by weight of triethylamine during oligomerization
0.28 kg / hour of aqueous solution and 0.83 kg of 24 wt% methylene chloride solution of pt-butylphenol.
/ H each was added to the oligomerization tank. At this time, the oligomer (hereinafter referred to as "BPP oligomer") had a viscosity average molecular weight (Mv) of 2,600, a terminal chloroformate group concentration of 0.42 N, and a terminal phenolic OH group concentration of 0.05 N.

25.6 kg of a methylene chloride solution of the BPC oligomer thus obtained and BPP oligomer 2
4.4 kg was mixed and charged into a reactor with a Faudler blade having an internal volume of 150 liters, 25 kg of methylene chloride for dilution was added thereto, 5.36 kg of 25% by weight aqueous sodium hydroxide solution, 6 kg of water, and 2 parts of triethylamine. .2 g, and stirred at 10 ° C. under a nitrogen gas atmosphere,
A polycondensation reaction was performed for 120 minutes to obtain a polycarbonate copolymer.

To this reaction solution, 30 kg of methylene chloride and 7 kg of water were added, and after stirring for 20 minutes, the stirring was stopped,
The aqueous and organic phases were separated. 0.1N to the separated organic phase
After adding 20 kg of hydrochloric acid and stirring for 15 minutes to extract triethylamine and a small amount of the remaining alkaline component, stirring was stopped and the aqueous phase and the organic phase were separated. Further, 20 kg of pure water was added to the separated organic phase, and after stirring for 15 minutes, the stirring was stopped and the aqueous phase and the organic phase were separated. This operation was repeated (3 times) until chlorine ions in the extracted waste water were not detected. The obtained purified polycarbonate solution was faded into warm water to obtain polymer powder and dried in a ventilating dryer at 120 ° C. for 48 hours under a nitrogen atmosphere. The obtained polycarbonate copolymer (hereinafter referred to as “C-3”) has a viscosity average molecular weight (Mv) of 30,100, a molecular terminal chloroformate group concentration of 0.002 μeq / g, and is incorporated into the molecular terminal. The nitrogen content was 4.2 ppm.

Example 4 The same operation as in Example 2 was performed except that the amount of liquefied phosgene supplied to the pipe reactor was 8.51 kg / hour. The resulting oligomer had a viscosity average molecular weight (Mv) of 1,400, a terminal chloroformate group concentration of 0.65N, and a terminal phenolic OH group concentration of 0.05N. 50 kg of the methylene chloride solution of the above oligomer was charged into a reactor with a Faudler blade having an internal volume of 150 liters, and BPC71
When 3 g and 808 g of BPP were added and dissolved, the OH group concentration of the oligomer became 0.30 N. Add 25 kg of methylene chloride for dilution to this, and add 25% by weight.
4.88 kg of sodium hydroxide aqueous solution, 6 kg of water, and 2.2 g of triethylamine were added, and the mixture was added under a nitrogen gas atmosphere to 10
The mixture was stirred at 0 ° C. and polycondensation reaction was performed for 120 minutes to obtain a polycarbonate copolymer.

To this reaction solution, 30 kg of methylene chloride and 7 kg of water were added, and after stirring for 20 minutes, the stirring was stopped,
The aqueous and organic phases were separated. 0.1N to the separated organic phase
After adding 20 kg of hydrochloric acid and stirring for 15 minutes to extract triethylamine and a small amount of the remaining alkaline component, stirring was stopped and the aqueous phase and the organic phase were separated. Further, 20 kg of pure water was added to the separated organic phase, and after stirring for 15 minutes, the stirring was stopped and the aqueous phase and the organic phase were separated. This operation was repeated (3 times) until chlorine ions in the extracted waste water were not detected. The obtained purified polycarbonate solution was faded into warm water to obtain polymer powder and dried in a ventilating dryer at 120 ° C. for 48 hours under a nitrogen atmosphere. The obtained polycarbonate copolymer (hereinafter referred to as “C-4”) has a viscosity average molecular weight (Mv) of 31,800, a molecular terminal chloroformate group concentration of 0.001 μeq / g, and it was incorporated at the molecular terminal. The amount of nitrogen was 5.2 ppm.

Comparative Example 1 The same operation as in Example 4 was carried out except that BPC and BPP were not added during polycondensation. The obtained polycarbonate copolymer (hereinafter referred to as "C-5")
Has a viscosity average molecular weight (Mv) of 30,600, a molecular terminal chloroformate group concentration of 0.002 μeq / g,
The amount of nitrogen taken in at the molecular end was 16.7 ppm.

[Comparative Example 2] BPA 15.6 kg / hr, sodium hydroxide 5.63 kg / hr, and water 101.1 kg
Per hour was dissolved at 35 ° C. in the presence of 0.018 kg / hour of hydrosulfite, then the aqueous phase was cooled to 25 ° C., and 60.5 kg / methylene chloride cooled to 5 ° C.
The organic phase at this time is supplied to stainless pipes each having an inner diameter of 6 mm and an outer diameter of 8 mm, mixed in the pipes, and further homomixer (manufactured by Tokushu Kika Co., Ltd., product name TK homomic line flow LF- Emulsified to prepare an emulsion.

The emulsion of the aqueous solution of BPA sodium salt (aqueous phase) and methylene chloride (organic phase) thus obtained was branched from a homomixer, and the inner diameter was 6 mm and the outer diameter was 8 mm.
In a Teflon pipe reactor having an inner diameter of 6 mm and a length of 34 m, which is connected to the pipe, the liquefied phosgene 6.98 kg / hour supplied from a pipe cooled separately to 0 ° C. is brought into contact therewith. .

The emulsion was subjected to phosgenation and oligomerization reaction while flowing through phosgene and a pipe reactor at a linear velocity of 1.7 m / sec for 20 seconds. At this time, the reaction temperature was adjusted to 60 ° C., and external cooling was performed to 35 ° C. before entering the next oligomerization tank. The oligomerized emulsion thus obtained from the pipe reactor is further introduced into a reaction tank equipped with a stirrer and having an internal volume of 50 liters, and the mixture is stirred at 30 ° C. under a nitrogen gas atmosphere to be oligomerized. After completely consuming the unreacted Na salt of the aromatic diol, the aqueous phase and the organic phase were separated by standing to obtain a solution of the oligomer in methylene chloride. In the case of oligomerization, 2 of triethylamine
A weight% aqueous solution of 0.28 kg / hr and a 24 wt% methylene chloride solution of pt-butylphenol of 1.0
Each was added to the oligomerization tank at 3 kg / hr. At this time, the oligomer had a viscosity average molecular weight (Mv) of 3,800, a terminal chloroformate group concentration of 0.36 N, and a terminal phenolic OH group concentration of 0.20 N.

50 kg of the methylene chloride solution of the above oligomer was charged into a reaction vessel with an internal volume of 150 L and equipped with a Faudler blade, and 25 kg of methylene chloride for dilution was added thereto.
Is added, and further 25 wt% sodium hydroxide aqueous solution 3.85 kg, water 6 kg, and triethylamine 2.2.
g was added, the mixture was stirred at 30 ° C. under a nitrogen gas atmosphere, and a polycondensation reaction was performed for 120 minutes to obtain a polycarbonate. To this reaction solution, add 30 kg of methylene chloride and 7 kg of water,
After stirring for 20 minutes, the stirring was stopped and the aqueous phase and the organic phase were separated. 20 kg of 0.1N hydrochloric acid was added to the separated organic phase, and the mixture was stirred for 15 minutes to extract triethylamine and a small amount of the remaining alkaline component. Then, the stirring was stopped and the aqueous phase and the organic phase were separated. Furthermore, 20 k of pure water is added to the separated organic phase.
After adding g and stirring for 15 minutes, the stirring was stopped and the aqueous phase and the organic phase were separated. This operation was repeated (3 times) until chlorine ions in the extracted waste water were not detected.

The purified polycarbonate solution thus obtained was faded into warm water to obtain polymer powder and dried in a ventilating dryer under a nitrogen atmosphere at 120 ° C. for 48 hours. The obtained polycarbonate (hereinafter referred to as "C-6") has a viscosity average molecular weight (Mv) of 30,000, a molecular terminal chloroformate group concentration of 0.001 µeq / g, and nitrogen incorporated at the molecular terminal. The amount was 23.7 ppm.

[Test Example] 10 parts by weight of the bisazo compound represented by the following (A) was added to 150 parts by weight of 4-methoxy-4.
-In addition to methylpentanone-2, pulverization and dispersion treatment was performed with a sand grind mill. The pigment dispersion obtained here was added to a 5% dimethoxyethane solution of polyvinyl butyral (Sekisui Chemical Co., Ltd., trade name BH-3) to finally prepare a dispersion having a solid content concentration of 4.0%. did.

[0104]

[Chemical 17]

An aluminum cylinder having an outer diameter of 80 mm, a length of 340 mm and a wall thickness of 2.0 mm, the surface of which was mirror-finished, was dip-coated on the dispersion liquid thus obtained, and the dry film thickness was about 0.4 μm. The charge generation layer was provided so that
Next, this aluminum cylinder was obtained by dissolving 90 parts by weight of a hydrazone compound represented by (B) below and 100 parts by weight of the polycarbonate resin obtained in Examples 1 to 3 and Comparative Example 2 in 900 parts by weight of dioxane. A photoreceptor was prepared by dip coating in a coating solution and forming a charge transfer layer so that the film thickness after drying was 20 μm.

[0106]

[Chemical 18]

The thus prepared photoconductor was mounted on an evaluation machine imitating a copying machine or a printer, and a copy test was conducted on 100,000 sheets to measure the most stable electric characteristics at that time. The results are shown in Table 1. Here, a method of measuring each potential will be briefly described. The developing tank of the copying machine was removed, and an electrometer sensor was attached to the part. Next, place a half-white original document and a half-black original document on the original plate of the copying machine in half and measure the potential of the black background portion as the charging potential (Vo) and the potential of the white background portion as the sensitivity (VL) when copying this original document. did. The potential remaining after static elimination was measured as the residual potential (Vr). Table 1 shows the evaluation results using the polycarbonate copolymers produced in Examples 1 to 3 and Comparative Example 2.

[0108]

[Table 1]

[0109]

EFFECT OF THE INVENTION The polycarbonate copolymer obtained by the present invention has few nitrogen and terminal chloroformate groups incorporated at the molecular terminals, and has excellent electrical properties when used as an electrophotographic photoreceptor.

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Toshimitsu Inoue             1-1 Kurosaki Shiroishi, Hachiman Nishi Ward, Kitakyushu City, Fukuoka Prefecture               Within Mitsubishi Chemical Corporation (72) Inventor Shigeo Higashi             1-1 Kurosaki Shiroishi, Hachiman Nishi Ward, Kitakyushu City, Fukuoka Prefecture               Within Mitsubishi Chemical Corporation F term (reference) 2H068 AA13 BB20 BB26 BB52 BB53                       EA04                 4J029 AA10 AB02 AC02 AC04 AD01                       AE18 BB10A BB12C BB13A                       BB13B BD09A BD09C BE05A                       BF14A BG08X BG08Y BH02                       DB07 DB11 DB13 FA07 FA16                       FC33 HA01 HC01 HC04 JA091                       JF031 JF041 KB02 KD01                       KE11 KE15

Claims (14)

[Claims] 1. A polymer having at least two types of structural units selected from structural units represented by the following general formula (1), having a viscosity average molecular weight of 5,000 to 100,000, and being incorporated at a molecular end. The amount of nitrogen is 10 ppm or less, and
A polycarbonate copolymer, wherein the amount of chloroformate groups at the molecular ends is 0.1 μeq / g or less. [Chemical 1] Or a single bond, R ¹ and R ² are a hydrogen atom or a carbon number of 1 to
20 alkyl groups, optionally substituted aryl groups,
Or a halogenated alkyl group, Z is a substituted or unsubstituted carbocycle having 4 to 20, Y ¹ to Y ⁸ are each independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 20 carbon atoms. Represents an optionally substituted aryl group or a halogenated alkyl group. ) 2. The ratio of the structural unit with the highest content is 30 to 95% by weight among at least two types of structural units selected from the structural units represented by the general formula (1). Polycarbonate copolymer of. 3. A compound having at least two kinds of structural units selected from structural units represented by the following general formula (2):
Or the polycarbonate copolymer according to 2. [Chemical 2] (In the general formula (2), X is an oxygen atom, a cycloalkylidene group having 5 to 10 carbon atoms, or —CR ¹ R ² —, and R ^{1 is}
And R ² is a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, or a phenyl group, and Y
¹ to Y ⁸ are hydrogen atom, chlorine atom, bromine atom, methyl group, ethyl group, n-propyl group, isopropyl group, se
c-butyl group, n-butyl group, isobutyl group, tert
A butyl group or a phenyl group. ) 4. A structural unit represented by the following formula [1-1] is 1
The polycarbonate copolymer according to claim 1 or 2, containing 0 to 90% by weight. [Chemical 3] 5. The structural unit represented by the following formula [1-2] is 1
The polycarbonate copolymer according to claim 1 or 2, containing 0 to 90% by weight. [Chemical 4] 6. The polycarbonate copolymer according to claim 1, which contains 10 to 90% by weight of a structural unit represented by the following formula [1-5]. [Chemical 5] 7. The polycarbonate copolymer according to any one of claims 1 to 6, wherein a molecular end of the polycarbonate copolymer has a phenyl group which may be substituted with an alkyl group having 1 to 20 carbon atoms at a para position. Coalescing. 8. A carbonate oligomer obtained by reacting at least two aromatic diols selected from the aromatic diols represented by the following general formula (3), a carbonate-forming compound, and a monophenol. ,
The carbonate oligomer having a ratio of the terminal chloroformate group concentration to the OH group concentration of 1.1 to 10 is
A method for producing a polycarbonate copolymer, which comprises performing polycondensation in the presence of an alkali under a temperature condition of ℃ or less. [Chemical 6] Or a single bond, R ′ ¹ and R ′ ² represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a halogenated alkyl group, and Z is 4 to 20.
Represents a substituted or unsubstituted carbocycle, Y ¹ to Y ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or
Indicates a halogenated alkyl group. ) 9. A carbonate oligomer obtained by reacting at least one aromatic diol selected from the aromatic diols represented by the following general formula (3), a carbonate-forming compound, and a monophenol: And a carbonate oligomer in which the ratio of the terminal chloroformate group concentration to the OH group concentration is 1.1 to 10, and b) different from the aromatic diols used in a), and the following general formula (3) A carbonate oligomer obtained by reacting at least one other aromatic diol selected from the following aromatic diols, a carbonate-forming compound, and a monophenol, wherein the terminal chloroformate with respect to the OH group concentration is Ratio of base concentration is 1.1 to 10
The method for producing a polycarbonate copolymer is characterized by carrying out polycondensation of two kinds of the above-mentioned carbonate oligomer, which is the above-mentioned, in the presence of an alkali at a temperature condition of 15 ° C. or lower. [Chemical 7] Or a single bond, R ′ ¹ and R ′ ² represent a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or a halogenated alkyl group, and Z is 4 to 20.
Represents a substituted or unsubstituted carbocycle, Y ¹ to Y ⁸ are each independently a hydrogen atom, a halogen atom, an alkyl group having 1 to 20 carbon atoms, an optionally substituted aryl group, or
Indicates a halogenated alkyl group. ) 10. The method for producing a polycarbonate copolymer according to claim 8, wherein the carbonate-forming compound is represented by the following general formula (4). [Chemical 8] (In the general formula (4), R ³ and R ⁴ are each independently a chlorine atom,
It represents an alkoxy group having 1 to 6 carbon atoms. ) 11. A polycondensation reaction is carried out by bringing phosgene into contact with an emulsion containing an aromatic diol and / or an alkali metal salt thereof, water, and an organic solvent incompatible with water. 11. The method for producing a polycarbonate copolymer according to any one of 10. 12. A coating liquid for an electrophotographic photosensitive member, which comprises the polycarbonate copolymer according to claim 1. 13. An electrophotographic photosensitive member obtained by applying the coating liquid for electrophotographic photosensitive member according to claim 12 on a conductive support. 14. An electrophotographic photosensitive member using the polycarbonate copolymer according to claim 1.