JPH11140051A - Hindered phenol-amine compound, its production and electrophotographic photoreceptor using the same compound - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a new compound functioning to light stabilization and antioxidation of polymers and the other chemical materials and useful as a deterioration-preventing agent and a stabilizer for electrophotographic photoreceptors. SOLUTION: This compound is represented by formula I, e.g. bis(3,5-di-t- butyl-4-hydroxybenzyl)malonic acid bis(l-ethoxycarbonylmethyl-2,2,6,6-tetramethyl- piperidinyl)ester. The compound of formula I is obtained by subjecting, e.g. (A) a hindered phenol-amine compound of formula II to nucleophilic substitution reaction with (B) ethyl bromoacetate, as necessary, in the presence of (C) a desalting agent (e.g. sodium carbonate) in a solvent (e.g. dimethylformamide) at 100-160 deg.C. A molar ratio of the components A/B/C is preferably 1:(2-10):(0-10), more preferably 1:(2-3):(2-4).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a novel hindered phenol / amine compound which functions to stabilize the light of polymers and other chemical products and to prevent oxidation, a process for producing the same, and a process for producing the same. It relates to an electrophotographic photosensitive member.

[0002]

2. Description of the Related Art Hindered phenol compounds having a 2,6-di-t-butylphenol skeleton and 2,2,6,6
-A hindered amine compound having a tetramethylpiperidine skeleton has a function of trapping a radical species generated by heat or light, and is known to be useful as an additive that suppresses deterioration of a resin that proceeds by a radical chain mechanism. I have.
Therefore, various hindered phenol compounds and hindered amine compounds have been researched and developed, and have been used as deterioration inhibitors for polymers, rubbers, foods, and other chemical materials and products.

In recent years, an organic photoconductor having a photosensitive layer containing an organic photoconductive compound as a main component has been used as an electrophotographic photoconductor.
In particular, research and development of a function-separated organic photoreceptor in which the carrier generation function and the carrier transport function are provided in different substances,
Some are practically used.

The surface layer of such an organic photoreceptor is subjected to electrical and mechanical external forces such as corona charging, toner development, transfer to paper, and cleaning, so that it is required to have durability against these. In addition, when the photoconductor is actually used in a copying machine or a printer, the photoconductor undergoes surface deterioration due to discharge products such as ozone and nitrogen oxide (NOx) generated at the band electrode and ultraviolet rays at the time of exposure. Resistance to these (environmental resistance) is also required.

As one technical measure against such photoconductor deterioration, it has been proposed to add a hindered amine compound or a hindered phenol compound as a deterioration prevention / stabilizer to the photoconductor. For example, JP-A-63-1835
No. 5, 63-73255.

[0006] However, the above-mentioned additives which have been researched and developed or marketed so far do not include ultraviolet rays, ozone,
Although the effects of NOx and the like are reduced, the sensitivity and residual potential may be deteriorated. In recent years, with the increase in the sensitivity of photoconductors, they have been installed in copiers and printers with higher printing speed and higher printing durability. The conventional photoconductors are not sufficiently durable due to the fact that conventional photoconductors have become increasingly demanded, and the miniaturization of copiers and printers has made it difficult to remove discharge products from around the photoconductors. Has become.

[0007]

SUMMARY OF THE INVENTION In view of the above problems, an object of the present invention is to provide a novel hindered phenol / amine compound useful as an additive for an electrophotographic photoreceptor, a method for producing the same, and a hindered phenol of the present invention. An object of the present invention is to provide an electrophotographic photosensitive member containing an amine compound and having excellent durability.

[0008]

The above objects of the present invention have been attained by the following constitutions.

(1) A hindered phenol / amine compound represented by the following chemical formula (A):

[0010]

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(2) A method for producing a hindered phenol / amine compound represented by the above chemical formula (A), comprising reacting a hindered phenol / amine compound represented by the following chemical formula (B) with ethyl bromoacetate.

[0012]

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(3) In an electrophotographic photosensitive member having a photosensitive layer having at least a carrier-generating substance and a carrier-transporting substance as main components on a conductive support, the photosensitive layer is represented by the chemical formula (A). An electrophotographic photoreceptor comprising a hindered phenol / amine compound.

(4) The electrophotographic photosensitive member as described in (3) above, wherein the carrier transporting substance is a triphenylamine compound represented by the following general formula (C).

[0015]

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Wherein R ₃ , R ₄ and R ₅ each independently represent an alkyl group or an alkoxy group having 1 to 5 carbon atoms. Also, n,
m and l each independently represent an integer of 0 to 3. Ar represents a hydrogen atom or a substituted or unsubstituted phenyl group. (5) The electrophotography according to the above (3) or (4), wherein the carrier-generating substance is titanyl phthalocyanine having a peak at a Bragg angle 2θ of 9.5 °, 24.1 ° 27.2 ° in X-ray diffraction. Photoconductor.

(6) The electrophotographic photoreceptor as described in (3) or (4) above, wherein the carrier-generating substance is a bisazo compound represented by the following chemical formula (D).

[0018]

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(7) The electrophotographic photoreceptor as described in (3) or (4) above, wherein the carrier-generating substance is a perylene compound represented by the following chemical formula (E).

[0020]

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The present inventor has reported that an electrophotographic photosensitive member to which the hindered phenol / amine compound of the present invention is added (hereinafter, also simply referred to as a photosensitive member) has excellent electrophotographic characteristics and discharge products generated by corona charging or the like. It is a highly durable photoreceptor that suppresses the influence of and provides stable potential characteristics and image quality even when used repeatedly. It has been found that this compound is useful as a stabilizer for preventing deterioration of electrophotographic photoreceptors and as a stabilizer. .

The hindered phenol / amine compound represented by the chemical formula (A) of the present invention is a novel compound. The hindered phenol / amine compound represented by the chemical formula (A) according to the present invention is synthesized by a nucleophilic substitution reaction in which ethyl bromoacetate is heated with a hindered phenol / amine compound represented by the chemical formula (B) in a suitable solvent. be able to.

The solvent used in the reaction has an appropriate boiling point,
Preferred are polar solvents having polarity, such as dimethylformamide, nitrobenzene, dimethylsulfoxide, and dimethylacetamide. Non-polar solvent xylene,
With dichlorobenzene and the like, the reaction did not proceed easily, and at a high temperature at which the reaction slightly occurred, the decomposition reaction occurred at the same time, which was not preferable. The reaction temperature is preferably from 100 ° C. to 160 ° C., and if it is higher than that, many decomposition reactions are unpreferable.
In order to remove hydrogen bromide generated by the reaction from the reaction system, an alkali metal carbonate may be added as a desalting agent. Specific examples include sodium carbonate, potassium carbonate, lithium carbonate and the like.

The molar ratio of the hindered phenol / amine compound represented by the chemical formula (B) to ethyl bromoacetate and the desalting agent is preferably from 1: 2 to 10: 0 to 10, more preferably from 1: 2 to 3: 2. ~ 4.

Next, specific examples of the photoreceptor to which the compound of the present invention is added will be described. The layer constitution of the photoreceptor of the present invention may be a single layer constitution in which a carrier generating substance and a carrier transporting substance are dispersed in a binder resin, or a carrier generating layer containing a carrier generating substance and a carrier transporting layer containing a carrier transporting substance. A stacked configuration may be used. If necessary, an intermediate layer may be provided between the conductive support and the photosensitive layer,
A protective layer may be provided on the photosensitive layer.

The compound of the present invention is added in an amount of 0.1 to 20% by weight, more preferably 1 to 10% by weight in the layer.

As the carrier transporting substance used in the photoreceptor of the present invention, any known substances can be used.
For example, a triarylamine compound, a triarylamine styryl compound, a hydrazone compound, and a pyrazoline compound can be used. Particularly, a triphenylamine compound represented by the above general formula (C) is preferable.

In the general formula (C), R ₃ , R ₄ and R ₅ each independently represent an alkyl group or an alkoxy group having 1 to 5 carbon atoms, particularly preferably a methyl group or a methoxy group. N, m, and l each independently represent an integer of 0 to 3.

Ar represents a hydrogen atom or a substituted or unsubstituted phenyl group, particularly preferably a phenyl group.

Next, specific examples of the compound represented by formula (C) will be described, but the compound of the present invention is not limited thereto.

[0031]

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[0032]

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As the carrier-generating substance used in the photoreceptor of the present invention, any known substances can be used. For example, various phthalocyanine compounds, azo compounds,
Pyrylium compounds, perylene compounds, cyanine compounds, squarium compounds, and polycyclic quinone compounds can be used.

Among the phthalocyanine compounds, titanyl phthalocyanine is preferable, and in particular, the Bragg angle 2θ in X-ray diffraction having a specific crystal system is 9.5 ° and 24.1.
And titanyl phthalocyanine having a peak at 27.2 ° are preferred.

Among the azo compounds, the above-mentioned chemical formula (D)
Are preferred, and among the perylene compounds, the perylene compounds represented by the above chemical formula (E) are preferred.

Examples of the binder resin used in the photoreceptor of the present invention include polycarbonate resin, polystyrene resin, polyacryl resin, polyvinyl butyral resin, epoxy resin, polyurethane resin, phenol resin, polyester resin, alkyd resin, silicone resin, and melamine. Resins and copolymer resins containing two or more of the repeating units of these resins. In addition to these insulating resins, a polymer organic semiconductor such as poly-N-vinyl carbazole may be used.

The resin used for the intermediate layer of the present invention is, for example, a polyamide resin, a vinyl chloride resin, a vinyl acetate resin, or a copolymer resin containing two or more of repeating units of these resins. Further, a curable metal resin compound obtained by thermally curing an organic metal compound such as a silane coupling agent or a titanium coupling agent may be used.

The photosensitive layer of the present invention comprises a dispersion prepared by dissolving or dispersing the compound of the present invention in a suitable solvent together with a binder resin and, if necessary, a carrier transporting substance and a carrier generating substance, in an applicator, bar coater, dip coater, circular slide hopper. It can be formed by coating and drying using the method described above. Examples of the solvent used for preparing the dispersion include hydrocarbons such as toluene and xylene; halogenated hydrocarbons such as methylene chloride and 1,2-dichloroethane; ketones such as methyl ethyl ketone and cyclohexanone; ethyl acetate and butyl acetate Esters such as methanol, ethanol, propanol, butanol, methylcellosolve and ethylcellosolve and derivatives thereof; tetrahydrofuran, 1,4-dioxane,
Ethers such as 1,3-dioxolane; amines such as pyridine and diethylamine; nitrogen compounds such as amides such as N, N-dimethylformamide; other fatty acids and phenols; sulfur and phosphorus such as carbon disulfide and triethyl phosphate; One or more kinds of compounds and the like can be used.

The conductive support for supporting the photosensitive layer may be a metal plate or a metal drum of aluminum, nickel, or the like, a plastic film on which aluminum, tin oxide, indium oxide, or the like is deposited, or a paper coated with a conductive material. -Plastic film drums can be used.

In addition, a dye for correcting color sensitivity may be added to the photoreceptor of the present invention. Further, other additives such as an antioxidant may be added in combination.

[0041]

EXAMPLES Synthesis Examples Bis (3,5-di-t-butyl-4-hydroxybenzyl) malonate bis (1-ethoxycarbonylmethyl) -malonate
Synthesis of 2,2,6,6-tetramethyl-piperidinyl) ester “Chemical Formula (A)” Bis (2,2,6,6) bis (3,5-di-t-butyl-4-hydroxybenzyl) malonate -Tetramethylpiperidinyl) ester (20.5 g; 0.025 mol),
Ethyl bromoacetate (9.2 g; 0.055 mol) and sodium carbonate (5.8 g; 0.055 mol) are added to dimethylformamide (100 ml), and the mixture is heated and stirred at 120 ° C. and reacted for 3 hours.

After the reaction, the reaction solution was poured into 800 ml of ice water, and the precipitated crystals were collected by filtration, washed twice with 500 ml of water with stirring, dried by filtration, and the crude crystals were dissolved in a mixed solvent of toluene / hexane and adsorbed. Purify by treating with silica gel and activated carbon. Finally, the product was recrystallized from acetonitrile water to give the desired product, bis (3,5-di-tert-butyl-4-).
9.8 g of bis (1-ethoxycarbonylmethyl-2,2,6,6-tetramethyl-piperidinyl) ester of hydroxybenzyl) malonic acid were obtained. The H ¹ -NMR (CDCl ₃ ) data of the present compound were as follows.

Δ 6.99 (4H, s) δ 5.07 (2
H, s) δ 5.02 (4H, m) δ 4.12 (4H, q) δ 3.25 (4H, s) δ
3.18 (4H, s) δ 1.70 (4H, dd) δ 1.48 (4H, m) δ 1.41 (18H, s) δ 1.23 (3H, t)
δ 1.06 (6H, s) δ 1.03 (6H, s) The melting point was 198 to 200 ° C.

FIG. 1 shows the IR data of this compound.

Example 1 A titanium coupling agent "TC750" (manufactured by Matsumoto Pharmaceutical Co., Ltd.) 3 was placed on a cylindrical aluminum drum subjected to Compax processing.
0 parts and 17 parts of a silane coupling agent “KBM503” (manufactured by Shin-Etsu Chemical Co., Ltd.) in 150 parts of isopropanol were dip-coated, and the mixture was cured by heating at 105 ° C. for 25 minutes to a thickness of 1.0 μm. Was provided.

Further, as a carrier generating substance, the Bragg angles 2θ in X-ray diffraction are 9.5 °, 24.1 °,
Titanyl phthalocyanine 1 having a peak at 27.2 °
0 parts, 10 parts of silicone resin “KR-5240” (manufactured by Shin-Etsu Chemical Co., Ltd.), and 1000 parts of t-butyl acetate dispersed by using a sand grinder were applied by a circular slide hopper to form a 0.3 μm-thick film. A carrier generation layer was formed.

Next, the carrier transport material (P-6) 120
A solution prepared by dissolving 6 parts of a hindered phenol / amine compound represented by the chemical formula (A) of the present invention and 160 parts of a polycarbonate resin “Iupilon Z-300” (manufactured by Mitsubishi Gas Chemical Co., Ltd.) in 1000 parts of ethylene chloride was used as a carrier. Coating on the generating layer with a circular slide hopper to a film thickness of 20
A μm carrier transport layer was formed.

Next, the carrier transport material (P-6) 120
Parts, chemical formula (A) compound 6 parts, polycarbonate resin “Iupilon Z-800” (manufactured by Mitsubishi Gas Chemical Company) 160
Of a solution in 1000 parts of ethylene chloride was coated on the carrier transport layer with a circular slide hopper to form a protective layer having a thickness of 8 μm.
After heating and drying for 1 minute, photoreceptor 1 was prepared.

Example 2 The carrier transporting substance (P-6) in Example 1 was replaced with (P-
A photoreceptor 2 was prepared in the same manner as in Example 1 except that the photoconductor 2 was changed to 12).

Comparative Example 1 A comparative photoreceptor 1 was prepared in the same manner as in Example 1 except that the compound of the formula (A) was omitted.

Comparative Example 2 A comparative photoreceptor 2 was prepared in the same manner as in Example 1 except that the compound of formula (A) in Example 1 was changed to the following comparative compound (H-1).

[0052]

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Evaluation 1 The photoconductors obtained in the respective Examples and Comparative Examples were used as a digital copier “Ko” manufactured by Konica Corporation as a durability test of potential stability.
nica 7050 ”and in a high temperature and high humidity environment (33
(80 ° C), a charge-discharge test of 10,000 times of exposure → exposure → static elimination was performed.
The intermediate potential Vg and the residual potential Vr (v) were measured.

The photosensitive members obtained in Examples and Comparative Examples were subjected to a forced deterioration test of environmental resistance by using NO using fuming nitric acid.
It was left exposed in an x exposure tank (about 5 ppm NO ₂ concentration). After exposure, after acclimation for 20 minutes, the standard chart was copied by attaching to a digital copying machine “Konica 7050” manufactured by Konica Corporation, and the image characteristics (image blur) of the obtained image were compared with Comparative Example 1. It was visually evaluated according to the following criteria.

(Visual evaluation criteria for image blur) 1: Large image blur 2: Image blur 3: Minimal image blur 4: No image blur The results are shown in Table 1.

[0056]

[Table 1]

Example 3 A polyamide resin "X1874" was placed on a cylindrical aluminum drum.
M "(manufactured by Daicel Huls) in 15 parts of methanol: n
An intermediate layer solution dissolved in 100 parts of a mixed solvent of -butanol = 9: 1 was applied by dip coating to provide an intermediate layer having a thickness of 0.5 μm.

Further, as a carrier-generating substance, 12 parts of a bisazo compound represented by the chemical formula (D), 4 parts of a polyvinyl butyral resin “ESREC BX-L” (manufactured by Sekisui Chemical Co., Ltd.), methyl ethyl ketone: cyclohexanone =
A liquid in which 500 parts of 19: 1 was dispersed using a sand grinder was applied by dip coating to form a 0.8 μm-thick carrier generation layer.

Next, the carrier transport material (P-11) 12
0 parts, chemical compound (A) 6 parts, polycarbonate resin "Iupilon Z-300" (manufactured by Mitsubishi Gas Chemical Company) 160
A part of the solution dissolved in 1000 parts of ethylene chloride was dip-coated on the carrier generating layer to form a carrier transporting layer having a thickness of 25 μm, and dried by heating at a drying temperature of 105 ° C. for 80 minutes to produce a photoreceptor 3. .

Comparative Example 3 A comparative photoreceptor 3 was prepared in the same manner as in Example 3 except that the compound of the formula (A) was omitted.

Comparative Example 4 A comparative photoreceptor 4 was prepared in the same manner as in Example 3 except that the compound of formula (A) in Example 3 was changed to the following comparative compound (H-2).

[0062]

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Evaluation 2 The photoconductors obtained in Examples and Comparative Examples were subjected to a durability test of potential stability by using a copy machine “Konica” manufactured by Konica Corporation.
4045 ”, in a high-temperature, high-humidity environment (33 ° C; 80 ° C).
%), An idling test of 10,000 charges → exposure → discharge was performed, and the charged potential Vh, the intermediate potential Vg, and the residual potential Vr (v) were measured at the initial stage and after repeated 10,000 times.

The photoreceptors obtained in the examples and comparative examples were subjected to a forced deterioration test of environmental resistance by using NO using fuming nitric acid.
It was left exposed in an x exposure tank (about 5 ppm NO ₂ concentration). After exposure, after acclimating for 20 minutes, the standard chart was copied by attaching to a copy machine “Konica 4045” manufactured by Konica Corporation, and the image characteristics (image blur) of the obtained image were evaluated based on Comparative Example 3. Visual evaluation was performed in the same manner as in Example 1.
Table 2 shows the results.

[0065]

[Table 2]

Example 4 A polyamide resin “CM800” was placed on a cylindrical aluminum drum.
No. 0 "(manufactured by Toray Industries, Inc.) was dissolved in 100 parts of a mixed solvent of methanol: n-butanol = 9: 1, and an intermediate layer solution was applied by dip coating to form an intermediate layer having a thickness of 0.3 μm.

Further, 5 parts of a perylene compound represented by the above formula (E), 1 part of a polyvinyl butyral resin “ESLEC BL-S” (manufactured by Sekisui Chemical Co., Ltd.), methyl ethyl ketone: cyclohexanone =
A liquid in which 8: 2 125 parts were dispersed using a sand grinder was applied by dip coating to form a 0.2 μm-thick charge generation layer.

Next, the carrier transport material (P-7) 100
Parts, chemical compound (A) compound 5 parts, polycarbonate resin “Iupilon Z-300” (manufactured by Mitsubishi Gas Chemical Company) 150
A part of the solution was dissolved in 1000 parts of methylene chloride, and the solution was applied onto the carrier generating layer by dip coating to form a carrier transporting layer having a thickness of 25 μm.

Next, the carrier transport material (P-7) 100
, A solution prepared by dissolving 5 parts of the compound of formula (A) and 150 parts of a polycarbonate resin "TS-2050" (manufactured by Teijin Chemicals Ltd.) in 1000 parts of ethylene chloride is coated on the carrier transport layer with a circular slide hopper to form a film. A protective layer having a thickness of 2 μm was formed, and dried by heating at a drying temperature of 110 ° C. for 60 minutes to produce a photoreceptor 4.

Comparative Example 5 A comparative photoreceptor 5 was prepared in the same manner as in Example 4 except that the compound of the formula (A) was omitted.

Comparative Example 6 A comparative photoreceptor 6 was prepared in the same manner as in Example 4 except that the compound of formula (A) in Example 4 was changed to the following comparative compound (H-3).

[0072]

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Evaluation 3 The photoconductors obtained in the respective Examples and Comparative Examples were subjected to a durability test of potential stability by using a copy machine “Konica” manufactured by Konica Corporation.
4355 ”, in a high-temperature, high-humidity environment (33 ° C; 80 ° C).
%), An idling test of 10,000 charges → exposure → discharge was performed, and the charged potential Vh, the intermediate potential Vg, and the residual potential Vr (v) were measured at the initial stage and after repeated 10,000 times.

The photosensitive members obtained in Examples and Comparative Examples were subjected to a forced deterioration test of environmental resistance by using NO using fuming nitric acid.
It was left exposed in an x exposure tank (about 5 ppm NO ₂ concentration). After exposure, after acclimation for 20 minutes, the standard chart was copied by attaching to a copy machine “Konica 4355” manufactured by Konica Corporation, and the image characteristics (image blur) of the obtained image were evaluated based on Comparative Example 5. Visual evaluation was performed in the same manner as in Example 1.
Table 3 shows the results.

[0075]

[Table 3]

As is clear from Tables 1, 2 and 3, the electrophotographic photoreceptor of the present invention exhibits stable electric and image characteristics even when used repeatedly and has excellent durability. It turns out that it is a body.

[0077]

According to the present invention, a novel hindered phenol / amine compound useful as an additive for an electrophotographic photoreceptor and a method for producing the same, and excellent durability including the hindered phenol / amine compound of the present invention are obtained. An electrophotographic photosensitive member could be provided.

[Brief description of the drawings]

FIG. 1 is an infrared absorption spectrum of a hindered phenol / amine compound of the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code FI G03G 5/06 380 G03G 5/06 380

Claims (7)

[Claims] 1. A hindered phenol / amine compound represented by the following chemical formula (A). Embedded image 2. A method for producing a hindered phenol / amine compound represented by the chemical formula (A), comprising reacting a hindered phenol / amine compound represented by the following chemical formula (B) with ethyl bromoacetate. Embedded image 3. An electrophotographic photoreceptor having a photosensitive layer having at least a carrier-generating substance and a carrier-transporting substance as main components on a conductive support, wherein the photosensitive layer has the hin- gle represented by the chemical formula (A). An electrophotographic photosensitive member containing a dirt phenol / amine compound. 4. The electrophotographic photoreceptor according to claim 3, wherein the carrier transporting material is a triphenylamine compound represented by the following general formula (C). Embedded image [In the formula, R ₃ , R ₄ and R ₅ each independently represent an alkyl group or an alkoxy group having 1 to 5 carbon atoms. N, m, and l each independently represent an integer of 0 to 3. Ar represents a hydrogen atom or a substituted or unsubstituted phenyl group. ] 5. The carrier generating substance according to claim 3, wherein the carrier generating substance is titanyl phthalocyanine having a peak at a Bragg angle 2θ of 9.5 °, 24.1 ° 27.2 ° in X-ray diffraction. Electrophotographic photoreceptor. 6. The electrophotographic photoreceptor according to claim 3, wherein the carrier generating substance is a bisazo compound represented by the following chemical formula (D). Embedded image 7. The electrophotographic photoreceptor according to claim 3, wherein the carrier-generating substance is a perylene compound represented by the following chemical formula (E). Embedded image