JPH01134463A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance durability and reliability by forming an electric charge retaining layer made of a silicone resin, and an adhesive layer made of one of hardened materials containing metal alkoxides, those of organic metal complexes, and those of silane coupling agents, and decomposition products of silyl isocyanate semiconductor. CONSTITUTION:The charge retaining layer is formed by dissolving the silicone resin, such as alkoxy-containing polysiloxanes, in a proper solvent, coating a photoconductive layer with this solution, and heat hardening it. The adhesive layer is formed by using one of the metal alkoxides such as tetramethoxysilane, the organic metal complexes such as zirconium tetrakis-acetylacetonate, the isocyanate-containing silane coupling agent, such as isocyanate-containing propyltrimethoxysilane, and alkyl silyl isocyanates RnSi(NCO)4-n and their condensation products, dissolving one of these materials for forming the adhesive layer in a proper solvent, coating the charge retaining layer, and heat hardening it, thus permitting the obtained photosensitive body to be made stable and durable against changes of environmental conditions and enhanced in image quality.

Description

DETAILED DESCRIPTION OF THE INVENTION [Technical Field] The present invention relates to improvements in electrophotographic photoreceptors, particularly electrophotographic photoreceptors having a protective layer on the surface of a photoconductive layer.

[Prior Art] Conventionally, electrophotographic photoreceptors include those in which particles of amorphous chalcogen represented by a-8e, ■-■ group compounds represented by CdS are dispersed in resin, and organic photoconductive materials. Recently, a-8i photoreceptors have been developed.

For such photoreceptors, the demand for f≦reliability to maintain high image quality for a long time is increasing year by year. However, when the photosensitive layer is exposed, damage caused by corona discharge during the charging process and physical or chemical damage caused by contact with other members during the copying process shorten the life of the photosensitive member.

In order to overcome this drawback, attempts have been made to provide a surface protective layer different from the photosensitive layer on the surface of the photoreceptor.

As one of these surface protective layers, acrylic resin, polyester resin (JP-A-53-3338), urethane resin (
A low-resistance protective layer has been proposed in which a layer containing a thermosetting resin, such as Japanese Patent Application Laid-Open No. 80-3838, is used and an appropriate resistance control agent is added thereto.

Photoreceptors with these protective layers have a certain degree of change in effect compared to those without a protective layer, but depending on the type of photosensitive layer, the adhesion between the protective layer and the photosensitive layer may be reduced. However, there is a problem that the chargeability deteriorates.

As a means to improve these problems, it has been proposed to provide an intermediate layer between the protective layer and the photosensitive layer to improve adhesion or to prevent charge injection.

These intermediate layers include an intermediate layer containing an inorganic compound as a main component (JP-A-57-30843), an intermediate layer containing an organic polymer compound as a main component (JP-A-57-30).
844), an intermediate layer containing an organometallic compound as a main component (JP-A-58-80748, JP-A-58-1210)
43, Japanese Patent Application Laid-Open No. 58-121045), etc., but even if a good screen is obtained at low humidity, there is a phenomenon in which the resolution decreases at high temperature.

The present applicant has proposed a photoreceptor for electrophotography in which an intermediate layer containing a silicone resin as a main component is provided between a photoreceptor layer and a protective layer as a photoreceptor that corrects these problems.

However, it has been found that when these intermediate layers are directly provided on the photosensitive layer, the adhesion between the intermediate layer and the protective layer is insufficient and the layer cannot withstand long-term use.

[Purpose] The present invention provides an electrophotographic photoreceptor with high image quality and durability by providing a protective layer that has high transparency and mechanical strength and is particularly stable against changes in environmental conditions such as humidity. This is what we provide.

[Yokosei] The present invention provides an electrophotographic photoreceptor in which a photoconductive layer, a charge retention layer, an adhesive layer, and a surface protection layer are sequentially laminated on a conductive support, wherein the charge retention layer is made of a silicone resin, and The present invention is an electrophotographic photoreceptor in which the adhesive layer is made of any one of a cured product containing a metal alkoxide, a cured product of an organometallic complex, a cured product of a silane coupling agent having an isocyanate group, or a decomposition product of silyl isocyanate.

The photoconductive layer of the photoreceptor used in the present invention includes Se,
5e-Te, Se alloys such as As2 Se3, Zn0SC
Used are particles of II-Vl group compounds such as dS and CdSe dispersed in resin, organic photoconductive materials such as polyvinyl carbazole, or a-8L.

There are no particular restrictions on the structure of the photoconductive layer, and it may be a single layer or a laminate of a Gs generation layer and an image transport layer.

The silicone resin used in the charge protection layer of the present invention has (1) an alkoxy group-containing polysiloxane (2) a hydroxyl group-containing polysiloxane (3) at least one amino group, imino group, or nitrile group bonded to a carbon atom. It consists of a composition whose main component is an organic silicon compound having a silicon atom to which two or three alkoxy groups are bonded.

The content of Si and O in the cured silicone resin is in the range of 50 to 88 V% with respect to the total amount of the charge retention layer, and the content of H is in the range of C: 10 to 10% with respect to the total amount of the charge retention layer.
30vt%, H: l~10vt%, N1-10vt
% range.

In order to form the charge retention layer of the present invention, a solution prepared by dissolving the silicone resin in a suitable solvent such as ligroin or hexane may be coated on the photoconductive layer and then heated and cured. The thickness of the charge retention layer is less than 1μ.

The metal alkoxide used in the adhesive layer of the present invention is not particularly limited, but examples thereof include tetramethoxysilane, tetraethoxysilane, tetrapropoxysilane, tetrabutoxysilane, tetraethoxysilane, tetrapropoxytitanium, tetrabutoxytitanium, and tetraethoxyzirconylam. , tetrapropoxyzirconium, tetrabutoxyzirconium, triethoxyaluminum, tripropoxyaluminum, tributoxyaluminum, triethoxyvanadium, tripropoxyvanadium, tributoxyvanadium, and the like. These metal alkoxides can be used alone or as a mixture of two or more.

Examples of the organometallic complexes include compounds such as zirconium tetrakisacetylacetonate, aluminum trisacetylacetonate, cobalt bisacetylacetonate, magnesium bisacetylacetonate, tin bisacetylacetonate, and titanium acetylacetonate.

Examples of the silane coupling agent having an isocyanate group include isocyanatepropyltrimethoxysilane, isocyanatepropyltriethoxysilane, isocyanatepropylmethyldimethoxysilane, and isocyanatepropylmethyljethoxysilane.

A solution of these adhesive layer forming materials dissolved in a suitable solvent such as groin or hexane may be applied onto the charge retention layer and then heated and cured.

Further, as silyl isocyanate compounds, there are generally the following compounds in which R is a functional group.

Alkylsilyl isocyanate type RnSi(NCO)4-m and its condensate Alkoxysilane isocyanate type (RO)-S L (NGO)a-1 and its condensate Tetraisocyanate type S L (NCO)4 and its condensation However, in the above, n −1 to 3.

Further, as specific functional groups for R, the following can be exemplified.

Hydrocarbon groups: methyl group, ethyl group, butyl group, octyl group, octadecyl group, phenyl group, benzyl group, etc. Unsaturated r&: vinyl group, acrylic group, allyl group, methacryl group, etc. -Alkoxy group: ethoxy group, propoxy group , phenoxy group, etc. The following can be exemplified.

Trimethylsilyl isocyanate Dimethylsilyl isocyanate Methylsilyl isocyanate Vinyl silyl isocyanate Phenylsilyl isocyanate Tetraisocyanate Silane ethoxysilane triisocyanate These silyl isocyanates can be used alone or in combination with 28
! It can also be used as a mixture of the above.

In order to form the adhesive layer of the present invention, a solution prepared by dissolving the silyl isocyanate in a suitable solvent such as n-butyl acetate may be applied onto the charge retention layer and then heated and cured. The thickness of the adhesive layer is preferably 0.1 μl or less, particularly 0.05 μm or less.

The protective layer used in the present invention is made of an organic polymer compound to which a suitable amount of a conductivity control agent such as an organic compound or an inorganic compound is added.

Specifically, organic compounds include anionic, cationic, and nonionic organic electrolytes, and inorganic compounds include metals such as gold, silver, copper, nickel, and aluminum, zinc oxide, titanium oxide, tin oxide, and indium oxide. , and metal oxides such as tin oxide containing antimony oxide and tin oxide containing indium oxide, and mixtures thereof may also be used.

The film thickness is 0.5 to 30 μm, preferably 1 to 10 μm. If the thickness is less than 0.5 μm, the mechanical strength of the protective layer is weak and the abrasion resistance is low, making the protective layer ineffective for long-term use. If the thickness is more than 30 μm, charges are accumulated in the protective layer. Residual potential increases with repeated use.

This protective layer is formed by mixing or dispersing a resistance control agent in the silicone resin and coating the photoconductive layer by dipping or spraying, or by forming it into a film and then adhering it.

The specific resistance of the protective layer is 1X10" to IX10"ΩC-, preferably tX10 to IX10"Ωc
It is 11. When the resistivity is less than IX to"ΩC-, the charge retention ability is low and image blur occurs, and IX to"ΩC- or less.
At C- or higher, the residual potential is large and background stains occur.

As the conductive support, a conductor or an insulator treated for conductivity is used. For example, AI.

AI and Ag on insulating substrates such as metals or alloys such as Ni, Fe, Cu, and Au, polyester, polycarbonate, polyimide, and glass.

Examples include those formed with a thin film of a metal such as Au or a conductive material such as In2O3, 5nOz, and paper treated with conductivity.

Further, there are no particular restrictions on the shape of the conductive support, and plate-like, drum-like, or belt-like ones may be used as required.

Examples and comparative examples of the present invention are shown below.

Example 1 After pre-treating (cleaning) an aluminum tube (801φ x 340--L), it was set in a vacuum evaporation device and Asz
A photoconductive layer was prepared by resistive heating vapor deposition of Se3 alloy on the support to a film thickness of 80 μm under the following conditions.

Vapor deposition conditions Vacuum degree 3 x 1G' Torr Support temperature 2
00°C Boat temperature 450°C Next, an intermediate layer forming liquid, that is, an alkoxy group-containing polysiloxane, a hydroxyl group-containing polysiloxane, and at least one amino group bonded to a carbon atom and 2 to 3 alkoxy groups are applied on this photoconductive layer. A silicone resin (manufactured by Toshi Silicone Co., Ltd., AY 42-441) whose main component is an organosilicon compound having bonded silicon atoms, and glue groin solution (solid content 5%) were applied to the intestine to a film thickness of 0.2 μm. Apply it so that it becomes 120
It was dried for 1 hour at °C to produce a charge retention layer.

Furthermore, an adhesive layer was created and applied under the conditions shown below! It was dried and cured at 20°C for 1 hour.

Adhesive layer forming liquid Ti (OC4HII) 4 (?Moto Trading Orgatics TA 25) 1 mIt part Ligroin
99ffi ffi part Furthermore, styrene-methacrylic acid-acrylic acid-N-methylolacrylamide resin liquid (solid content 40vt%) 80ff
1 part of tin oxide powder containing 1 part of antimony oxide and 10 vt% of antimony oxide
Add 0ffi parts and an appropriate amount of solvent, and mix in a ball mill for 7
Apply the dispersion solution by dipping for 2 hours and apply at 120"C for 30 minutes.
After drying for 30 minutes, a protective layer of about 5 μm thick was formed.

As a result of elemental analysis of the composition of the charge retention layer, it was found that it contained Si and 0! 1 B 7 , 8 wt%C content
22.7vt%H content 5
．． 8vL%N17) including f4m, 3.7
It was wL%.

Example 2 A photoreceptor was produced in exactly the same manner as in Example 1, except that the composition of the adhesive layer forming liquid was changed to the following.

Adhesive layer forming liquid Zr (OC4HI) 4 (Matsumoto Trading ZA80) 1 part by weight Ligroin
99 parts by weight Comparative Example 1 A comparative photoreceptor was produced in the same manner as in Example 1 except that no contacting layer was formed.

Photoreceptor of the present invention obtained as described above (Example 1.2)
The adhesion of the comparison photoreceptor was evaluated.

The adhesiveness of the protective film was evaluated by performing a heat cycle of 30 times at -10° C. to 70° C. and performing a square peel test. The evaluation results are shown in Table 1.

Example 3 After pre-treating (cleaning) an aluminum tube (80ssφX 340smL), set it in a vacuum evaporation apparatus and
A photoconductive layer was fabricated by resistive heating vapor deposition of the s2Se3 alloy on the support to a film thickness of 60 μm under the following conditions.

Vapor deposition conditions Vacuum degree: 3 x 10' Torr Support temperature
200°C Boat temperature 450°C Next, an intermediate layer forming liquid, that is, an alkoxy group-containing polysiloxane, a hydroxyl group-containing polysiloxane, and at least one amino group bonded to a carbon atom and 2 to 3 alkoxy groups are applied to the photoconductive layer. A silicone resin (manufactured by Toshi Silicone Co., Ltd., AY 42-441) whose main component is an organosilicon compound having bonded silicon atoms was coated with glue groin solution (solid content 5%) to a film thickness of 0.2μ. Apply it so that it becomes 120
It was dried for 1 hour at °C to produce a charge retention layer.

Further, an adhesive layer was formed thereon under the conditions shown below, and after coating, it was dried and cured at 120° C. for 1 hour.

Adhesive layer forming liquid titanium acetylacetonate 1 part by weight Ligroin
99 parts by weight Furthermore, on top of this, styrene-
Methacrylic acid-acrylic acid-N-methylolacrylamide resin, 30 parts by weight of resin liquid (solid content 40 vt%), 10 parts by weight of tin oxide powder containing 10 vt% of antimony oxide, and an appropriate amount of solvent were added and dispersed in a ball mill for 72 hours. The dispersion was applied by dip coating and dried at 120° C. for 30 minutes to provide a protective layer of about 5 μm.

As a result of analyzing the composition of this charge retention layer, it was found that the content of SL and 0 was Q B 7 , and the content of 8 v t%C was 22.
7wt% H content 5. J1wL%N content
It was 3.7vt%.

Example 4 Same as Example 3 except that the adhesive layer forming liquid was changed to the following composition (
A photoreceptor was produced in the same manner.

Adhesive layer forming liquid Zirconium acetylacetonate 1 part by weight Ligroin 99 parts by weight Comparative Example 2 A comparative photoreceptor was prepared in exactly the same manner as in Example 3 except that no adhesive layer was formed.

Photoreceptor of the present invention obtained as described above (Example 1.2)
The adhesion of the photoconductor for comparison was evaluated, and the evaluation results are shown in Table 1.

Example 5 After pre-treating (cleaning) an aluminum tube (80 Isφ x 340 mL), it was placed in a vacuum evaporation device and treated with As.
A photoconductive layer was prepared by resistively heating and steaming the zSe3 alloy under the following conditions so that the film thickness on the support was BOμ.

Vapor deposition conditions Vacuum degree: 3 x 10' Torr Support temperature: 2
00°C Boat temperature 450°C Next, an intermediate layer forming liquid, that is, an alkoxy group-containing polysiloxane, a hydroxyl group-containing polysiloxane, and at least one amino group bonded to a carbon atom and 2 to 3 alkoxy groups are applied on this photoconductive layer. A silicone resin (manufactured by Toshi Silicone Co., Ltd., AY 42-441) whose main component is an organosilicon compound having bonded silicon atoms was coated with glue groin solution (solid content 5%) to a film thickness of 0.2μ■. Apply it so that it becomes 120
It was dried for 1 hour at °C to produce a charge retention layer.

Furthermore, an adhesive layer was prepared on top of this under the conditions shown below, and after coating, it was dried and cured at 120°C for 1 hour.

Adhesive layer forming liquid Isocyanate Propyltriethoxysilane 1 fflr parts Ligroin 99 parts by weight Furthermore, on top of this, 30 parts by weight of styrene-methacrylic acid-acrylic acid-N-methylolacrylamide resin liquid (solid content 40 wt%) and oxidation containing tovt% of antimony oxide. Add 10 parts by weight of tin powder and an appropriate amount of solvent, disperse in a ball mill for 72 hours, apply the dispersion by dip coating, and dry at 120°C for 30 minutes.
A protective layer of approximately 5 μm was applied.

As a result of analyzing the composition of this charge retention layer, we found that Si and O('
) af-fm 87.8vt96C content Hk22, 7vt%H content In5, 8vt%N content Q 3.7vt%.

Comparative Example 3 A comparative photoreceptor was produced in the same manner as in Example 5 except that no adhesive layer was formed.

The adhesion of the photoreceptor of the present invention and the comparative photoreceptor obtained as described above was evaluated, and the evaluation results are shown in Table 1.

Example 6 After pre-treating (cleaning) an aluminum tube (80 φ x 340 mm L), it was placed in a vacuum evaporation device and subjected to AS
A photoconductive layer was prepared by resistive heating vapor deposition of a 2Se3 alloy on a support to a film thickness of 60 .mu.m under the following conditions.

Vapor deposition conditions Vacuum degree 3 x 1G' Torr Support temperature 2
00°C Boat temperature 450°C Next, an intermediate layer forming liquid, that is, an alkoxy group-containing polysiloxane, a hydroxyl group-containing polysiloxane, and at least one amino group bonded to a carbon atom and 2 to 3 alkoxy groups are applied on this photoconductive layer. A silicone resin (manufactured by Toshi Silicone Co., Ltd., AY 42-441) whose main component is an organosilicon compound having bonded silicon atoms was coated with glue groin solution (solid content 5%) to a film thickness of 0.2μ■. Apply it so that it becomes 120
It was dried for 1 hour at °C to produce a charge retention layer.

Furthermore, an adhesive layer was prepared on top of this under the conditions shown below, and after coating, it was dried and cured at 120° C. for 1 hour.

Adhesive layer forming liquid 1 part by weight of methylsilyl triisocyanate 99 parts by weight of n-butyl acetate Furthermore, on top of this, 30 parts by weight of styrene-methacrylic acid-acrylic acid-N-methylolacrylamide resin liquid (solid content 40 vL%) and antimony oxide tovt% Add 10 parts by weight of tin oxide powder and an appropriate amount of solvent, disperse in a ball mill for 72 hours, apply the dispersion by dip coating, and dry at 120°C for 30 minutes.
A protective layer of approximately 5 μm was provided.

As a result of analyzing the composition of this charge retention layer, the content of SL and O was 87.8vt%C.
22,7 vt%H content 5
．． The gvt%N content was 3.7wt%.

Example 7 A photoreceptor was produced in the same manner as in Example 6 except that the composition of the adhesive layer forming liquid was changed to the following.

Adhesive layer forming liquid Tetrasilyl isocyanate 1 part by weight n-butyl acetate 99 parts by weight Comparative Example 4 A comparative photoreceptor was prepared in exactly the same manner as in Example 6 except that no adhesive layer was formed.

Photoreceptor of the present invention obtained as described above (Example 1.2)
The adhesion of the photoconductor for comparison was evaluated, and the evaluation results are shown in Table 1.

Table 1 From the above results, it can be seen that the present invention is a photoreceptor with excellent adhesive strength.

[Effects] According to the present invention, an intermediate layer having superior environmental resistance compared to conventional intermediate layers can be obtained, and a photoreceptor with high durability and reliability can be obtained.

Claims (2)

[Claims] (1) In an electrophotographic photoreceptor in which a photoconductive layer, a charge retention layer, an adhesive layer, and a surface protection layer are sequentially laminated on a conductive support, the charge retention layer is made of silicone resin, and the adhesive layer is made of metal. An electrophotographic photoreceptor comprising any one of a cured product containing an alkoxide, a cured product of an organometallic complex, a cured product of a silane coupling agent having an isocyanate group, and a decomposition product of silyl isocyanate. (2) The composition of the silicone resin after curing is: (a) Silicon and oxygen content is 50 to 88% by weight (b) Carbon content is 10 to 30% by weight (c) Hydrogen content is 1 to 10% by weight (d) The electrophotographic photoreceptor according to claim 1, wherein the nitrogen content is in the range of 1 to 10% by weight.