JPH0625230B2 - Styrene-based copolymer having hydrazone group in side chain and method for producing the same - Google Patents

Description

TECHNICAL FIELD The present invention relates to a novel styrene copolymer having a hydrazone group and a method for producing the same, and more specifically, to an electron using a charge generating material and a charge transfer material. The present invention relates to a styrene-based copolymer having a hydrazone group which has an excellent function as a charge transfer material in a photographic photoreceptor and a method for producing the same.

[Prior Art and its Problems] Conventionally, selenium (Se), cadmium sulfide (Cd) have been used as photoconductive materials for photoconductors used in electrophotography.
S), zinc oxide (ZnO), amorphous silicon (a
-Si) and other inorganic substances. These inorganic photoconductors have many advantages, but at the same time have various drawbacks,
For example, it has drawbacks such as being harmful and high in cost. Therefore, in recent years, many organic photoconductors using organic substances without these defects have been proposed,
It has been put to practical use.

In addition, as the structure of these photoconductors, a material that generates charge carriers (hereinafter, referred to as charge generation material) and a material that receives the generated charge carriers and moves them (hereinafter,
(Referred to as charge transfer material)) and a single layer structure having a single layer type photoreceptor in which charge carrier generation and charge transfer are performed by the same material. However, the multi-layer structure is more widely used because it has a wider selection of materials and higher sensitivity.

In recent years, with the development of non-impact printing technology, research and development of electrophotographic printers using a laser light source has been actively conducted. In these devices, as the device size is reduced and the speed is increased, it is desired that the photosensitive material also has higher sensitivity of the charge generation material and higher mobility of the charge transfer material.

In the case of a charge transfer material, its mobility is known to largely depend on the concentration of the transfer material (eg triphenylamine compound) in the binder (eg polycarbonate) (Takahashi, Koubayashi, Yokoyama, Electrophotography) , 25 , 16
(1986)). If the concentration of the transfer material is increased, the mobility is increased, but the physical properties are deteriorated and, for example, cracking occurs. Further, mechanical abrasion becomes severe when the paper passes through during printing. Therefore, it is difficult to add the charge transfer material to the binder at a high concentration.

The present invention has been made in view of the conventional circumstances described above, and does not cause cracking or the like even when used at a high concentration, has mechanically excellent physical properties, and has high mobility. It is an object to provide a novel compound useful as a charge transfer material and a method for producing the same.

[Means for Solving the Problem] As a result of continuing the research in view of such a conventional situation, the present inventors have introduced a charge transfer agent into a side chain of a polymer, whereby the charge transfer agent has a high concentration. It was found that the high mobility was exhibited.

The present invention has the general formula [I]; (In the formula, R represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an alkoxyl group or a dialkylamino group), and a structural unit (the number of structural units: x); Consisting of structural units (the number of structural units: y) represented by
y is 1 such that 1> x / (x + y) ≧ 0.01 is satisfied.
Molecular weight of 1,000 to 5 characterized by the above integer
It is a styrene copolymer having a side chain of 00,000 hydrazone groups.

In addition, the production method is represented by the general formula [II]; A structural unit represented by the formula [III]; A 4-formylstyrene-based copolymer having a structural unit represented by the following general formula [IV]; (Wherein R represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an alkoxyl group or a dialkylamino group), or by reacting with a hydrazone compound represented by the general formula [V] ; (In the formula, R has the same meaning as above), and a hydrazone group-containing styrene compound represented by the formula [VI]; It is characterized by comprising co-copolymerizing with styrene represented by.

The styrene copolymer having a hydrazone group in the side chain according to the present invention can be produced, for example, as follows.

That is, in the first method, first, a Grignard reagent of 4-chlorostyrene is produced, and then dimethylformamide (DMF) is added to produce 4-formylstyrene.
(W. J. Dale, L. Starr and C.
W. Strobel, J .; Org. Chem. , 26 , 19
65, 2225). Then, after protecting the aldehyde group of 4-formylstyrene as an acetal, the compound and styrene are polymerized in the presence of a suitable polymerization initiator, and then hydrolyzed in an acidic solution to remove the acetal group. A 4-formylstyrene-based copolymer having the structural units represented by the general formulas [II] and [III] is produced.
Then, the styrene-based copolymer of the present invention can be obtained by reacting this copolymer with the hydrazine compound represented by the general formula [IV].

In addition, the second method is to prepare 4-formylstyrene in the same manner as above, then add the desired 1,1-diarylhydrazine compound to 4-formylstyrene and condense it in the presence of an acidic catalyst. A hydrazone group-containing styrene compound represented by the general formula [V] is produced. The styrene-based copolymer of the present invention can also be obtained by polymerizing this monomer and styrene [VI] using a polymerization initiator as required.

The copolymer of the present invention is readily soluble in solvents such as benzene, chloroform and methylene chloride, but insoluble in methanol and ethanol. Further, by casting a solution dissolved in methylene chloride, a hard film can be produced, and no cracks or the like are observed, and it is extremely useful as a charge transfer agent for electrophotographic photoreceptors. Is.

[Examples] Examples of the present invention will be described in detail below.

Example 1 In this example, a styrene-based copolymer represented by the formula (3) was produced by the method represented by the following series of reaction formulas.

(Where x and y are 1> x / (x + y) ≧
Representing an integer of 1 or more that satisfies 0.01) Production of Compound (1) 14.7 g of magnesium metal, 20 ml of ethyl ether and a small amount of ethyl bromide are added to a flask and heated to activate magnesium. It was Further, a solution of 81.8 g of 4-chlorostyrene / 400 ml of tetrahydrofuran (THF) was added over 3 hours. During the reaction, heat was generated and the temperature became high, so the reaction solution was kept at 50 ° C or lower by cooling with a water bath. After the dropping was completed, the reaction was continued for another 2 hours at room temperature. 43.8 g of dimethylformamide (DMF) was added dropwise over 2 hours, and the mixture was left at room temperature overnight. Ethyl ether 50
0 ml was added, and the reaction solution was added to a dilute hydrochloric acid aqueous solution. Extraction was performed, the ether layer was washed with pure water, and then dried over magnesium sulfate. After distilling ether, it was distilled to produce 4-formylstyrene (boiling point 70 ° C./0.8 mmHg). 42 g
(63%) yield.

Production of Compound (2) 66 g of the compound (1) produced by the above method, 92.5 g of 1,1-diphenylhydrazine, 300 ml of benzene, and a small amount of paratoluenesulfonic acid were charged into a 500 ml flask equipped with a Dean Stark receiver, Heated to reflux for 2 hours. After completion of the reaction, benzene was distilled off and recrystallized with methanol to give small crystals, which was a light yellow solid compound (2) having a melting point of 79 ° C.
Got

Preparation of Compound (3) 15 g of Compound (2), 5 g of styrene and 15 ml of benzene were charged into a 50 ml flask, and 0.5 g of azobisisobutyronitrile (AIBN) was added. After polymerization was carried out at 60 ° C. for 24 hours, the polymerization solution was poured into a large amount of methanol. The obtained solid was dried under reduced pressure at 50 ° C. A compound (3) having a yield of 17.5 g, a weight average molecular weight of 180,000 and a number average molecular weight of 84,000 was obtained.

Example 2 In this example, a styrene-based copolymer represented by the formula (3) was produced by the method represented by the following reaction formula.

(Where x and y are 1> x / (x + y) ≧
Represents an integer of 1 or more that satisfies 0.01) Poly (p-formylstyrene) 5 g, 1,1 in 100 ml
15 g of diphenylhydrazine and 50 ml of tetrahydrofuran (THF) were charged, and the reaction was carried out at room temperature for 4 hours.
After the reaction was completed, THF was distilled off under reduced pressure, 50 ml of benzene was added, and the solution was put into 500 ml of methanol. The solid product obtained was filtered and dried to give compound (3).
Was manufactured. The yield was 12.3 g.

Application Example 1 An underlayer made of nylon is formed on an Al substrate, and a butyral film (0.1 μm thick) containing phthalocyanine as a charge generation amount is formed on the underlayer. A methylene chloride (1: 1 weight ratio) solution was applied and baked at 80 ° C. for 30 minutes to form a charge transfer layer having a thickness of 15 μm.

After the surface potential was set to -1054 V by corona discharge of -5 kV using an electrostatic double tester, the light was irradiated so that the illuminance was 5 lux, and the time until the surface potential became 1/2 (second). Was obtained to obtain a half-exposure amount E _1/2 (lux · sec). The result is V _po = 1000 volts, E _1/2 = 0.96
It showed very high mobility with looks and seconds. The mechanical properties were also very good.

FIG. 1 is a schematic sectional view of the photoconductor manufactured in this application example.
In the figure, 1 is an Al substrate, 2 is a charge generation layer, 3 is a charge transfer layer, and 4 is a base layer.

[Effects of the Invention] As described above, the novel styrene-based copolymer according to the present invention has mechanically excellent physical properties and high mobility when used as a charge transfer material in an electrophotographic photoreceptor. And is expected to be useful as a material having excellent functions.

[Brief description of drawings]

FIG. 1 is a schematic sectional view of an electrophotographic photosensitive member using the copolymer obtained in one example of the present invention. 1 ... Al substrate 2 ... Charge generation layer 3 ... Charge transfer layer 4 ... Underlayer

Claims (3)

[Claims] 1. A general formula; (In the formula, R represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an alkoxyl group or a dialkylamino group), and a structural unit (the number of structural units: x); Consisting of structural units (the number of structural units: y) represented by
y is 1 such that 1> x / (x + y) ≧ 0.01 is satisfied.
Molecular weight of 1,000 to 5 characterized by the above integer
A styrene-based copolymer having 00,000 hydrazone groups in the side chain. 2. A formula; A structural unit represented by: A 4-formylstyrene-based copolymer having a structural unit represented by: (Wherein R represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an alkoxyl group or a dialkylamino group), and a general formula characterized by reacting with a hydrazine compound represented by the formula: (Wherein R has the same meaning as described above), and a formula unit; A method for producing a styrene-based copolymer having a hydrazone group having a molecular weight of 1,000 to 500,000 and having a structural unit represented by. 3. A general formula; (Wherein R represents a hydrogen atom, a lower alkyl group having 1 to 4 carbon atoms, an alkoxyl group or a dialkylamino group), and a styrene compound containing a hydrazone group represented by the formula: A general formula characterized by being copolymerized with styrene represented by: (Wherein R has the same meaning as described above), and a formula unit; A method for producing a styrene-based copolymer having a hydrazone group having a molecular weight of 1,000 to 500,000 and having a structural unit represented by.