JPS60256154A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To enhance surface hardness and smoothness, and to obtain good durability and cleanability by forming an insulating layer contg. a silicic acrylic resin contg. specified silicic polymerizable monomer units or an fluorine contg. acrylate resin contg. specified polymerizable monomer units on a photoconductive layer. CONSTITUTION:The insulating layer formed on the photoconductive layer contains an Si-contg. acrylate contg., as one structural element, Si-contg. polymerizable monomer units, each represented by formula I or II (R1 is H or methyl, R2 and R3 are each 1-8C alkyl, independent of each other) or an F-contg. acrylate resin, as an essential component, contg. as one of components, polymerizable monomer units each represented by formula III in which R1 is same as before, and Rf is 1-8C fluorinated alkyl or fluorinated hydroxyalkyl. Such an Si-contg. or F-contg. monomre is copolymerized, preferably, randomly with acrylic or methacrylic acids or the like. The formation of the insulating layer made of such a copolymer permits superior sensitivity to be obtained and printing and abrasion resistances to be enhanced.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Application in Industry The present invention relates to an electrophotographic photoreceptor, in particular, a photosensitive layer formed by dispersing photoconductive material particles in a binder made of an insulating polymeric material on a substrate. The present invention relates to an improvement in an electrophotographic photoreceptor formed by.

Prior Art In general, in electrophotography, the surface of the photosensitive layer of a photoreceptor is charged and exposed to form an electrostatic latent image, and this is developed with a developer to make it visible to obtain a visible image. There is a method using the so-called PPC method, in which the visible image is transferred to a transfer paper-1- such as paper, and the transferred image is fixed to obtain a copy image.

The photoreceptor also has various configurations depending on the type of PPC electrophotographic process. As a typical electrophotographic photoreceptor, a photoreceptor having an insulating layer on its surface is widely used. This insulation I- protects the photoconductive layer, improves the mechanical strength of the photoreceptor, improves the nli attenuation characteristics, or
It is provided for the purpose of application to a specific electrophotographic process.

As a matter of course, the 7g true photoreceptor is required to have predetermined sensitivity, electrical properties, and optical properties in accordance with the electrophotographic process to which it is applied. However, the durability and cleanability of the photoreceptor are also important properties.

Durability is a property required when the photoreceptor is used repeatedly, and cleanability is a property that determines the ease with which toner remaining on the surface of the photoreceptor can be removed.

Originally, a photoreceptor equipped with an insulating layer has excellent durability due to the insulating layer, but it is pointed out that there are still points to be improved in terms of toner transferability, cleaning performance, and surface smoothness. .

On the other hand, when an insulating layer with excellent cleaning properties and surface smoothness is used, sensitivity generally tends to decrease, and therefore an insulating layer that satisfies all the requirements in item I has not yet been obtained.

Purpose of the Invention The present invention has excellent surface hardness and surface smoothness, and as a result,
An eleventh object of the present invention is to provide a photoreceptor having an insulating layer with excellent durability and cleanability.

Structure of the Invention The present invention provides an electronic photoreceptor having an insulating layer in the photoconductive layer, in which the insulating layer has the general formula: 1~
A silicon-containing acrylic material containing as one component a silicon-containing polymerizable monomer represented by the fullkylene group of 8 and Y<:l each independently representing an alkyl group having 91 to 8 carbon atoms.
fat or general formula: % formula % [111 amount 1 formula, R1 has the same meaning as above and Rf has 1 to 8 carbon atoms
Provided is an electrophotographic photoreceptor containing as a main component a fluorinated acrylic resin containing a polymerizable 111-mer represented by 1 representing a fluorinated alkyl group or a fluorinated hydroxyalkyl group.

The silicon-containing polymer used in the present invention has the general formula [11
or [tB having a silicon-containing monomer represented by 111, an ester, a nitrile or an amide of acrylic acid or methacrylic acid (hereinafter referred to as (meth)acrylic acid), and optionally a polymerizable ethylene bond. A random copolymer is preferable. In particular, it is preferable to use a thermosetting resin with an average molecular weight of 450 () to 2,000 (1) and a sharp molecular weight distribution.This is because when the average molecular weight reaches 20,000, the hardness of the photosensitive layer decreases and the printing durability decreases. -12 cannot be expected; conversely, if it is less than 4,500, dark decay increases and good characteristics cannot be obtained; in addition, the sharper the molecular weight distribution, the more constant the degree of crosslinking becomes, and the higher the charge retention ability. This is because it can be done.

In addition, this silicon-containing thermoset acrylic resin has a viscosity of 200 to 30 at 25°C when it is a 50% solution of nonvolatile components.
00 cps is preferred. This has a viscosity of 30
If it is higher than 00 cps, the dispersibility of the photoconductive material will be poor, and if it is lower than 200 cps, the sensitivity will be lowered and the coating properties will be poor, resulting in defects and holes in the photosensitive layer.

In the silicon-containing polymerizable monomer represented by the general formula [11 or In], R1 is hydrogen or a methyl group, R2 is a fullkylene group having 1 to 8 carbon atoms, preferably 1 to 4 carbon atoms, and R3
Compounds each independently being an alkyl group having 1 to 8 carbon atoms, preferably 1 to 5 carbon atoms can be suitably used. A particularly preferred silicon-containing monomer is CH2=CH3i(OCH-)
3, CH3 CI (2= CCOOCJ(2S + (OCH-)-
1H3 CH2= CCOOCH2CH2CH2S i(OCH
3) 1, C113 ■ C1l, =C-C()OC! 12C112Si((')
Cl13)3, C11゜■ Cl1==CC00CH2Si(OC:It,)3,1
13 Cl12"CCO(')CI-12C112Si(OC
211,)3,C1l,=C1l-CO('')C112
Si(OCII, )2, etc.

(Meth)acrylic acid esters that can be used in the present invention are:
General formula: % formula % 1 In the formula, R is hydrogen or ethylene, (, I<, represents hydrogen, an alkyl group having 1 to 12 carbon atoms, or a hydroxyalkyl group having 2 to 1 carbon atoms. It is a compound.

The polymerizable 1) monomer represented by the general formula [■1] includes:
Methyl methacrylate, ethyl methacrylate, butyl methacrylate, isobutyl methacrylate, meth-7-tert-butyl acrylate, butyl acrylate, acrylic acid 2
-Includes, but is not limited to, ethylhexyl, acrylic acid, methacrylic acid, 2-hydroxyethyl methacrylate, hydroxypropyl tutaacrylate, and the like.

In addition, as (meth)acrylamides, the general formula: % formula % 1 In the formula, Ro has the same meaning as above, ■<, hydrogen, carbon number 1
to 8, preferably 1 to 1 alkyl group, hydroxyalkyl group or alphkyl dimethyl group, and the tltmer represented by 11, specifically, acrylamide, methacrylamide, N-7 tyrolacrylamide, N- n-bu)
Examples include oxymethylacrylamide.

1-Blended silicon! Examples of monomers having a polymerization + 1-functional styrene & 11-polymerization which may be polymerized with the it @ body and (meth)acrylic acid esters include styrene, vinyl ll'llate, and the like. The amount of these monomers used should be less than 2.0% of the total amount of IF used.

Silicon-containing acrylic? Although it depends on the silicon content in the silicon-containing rBH substrate, the silicon-containing polymer content in the 41 fat is usually 5 to 7%, more preferably 10 ~50% by weight.

The silicon-containing heat-harvesting curable acrylate can be obtained by solution polymerization or emulsion polymerization of the above monomer and a (meth)acrylic monomer represented by the general formula (111) by a known method.

Fluorine-containing acrylic used in the present invention (1 fat is a fluorine-containing polymerizable monomer represented by the general formula Qt with
A copolymer with a polymer and a languum copolymer is preferred. In particular, it is preferable to use a thermosetting resin with an average molecular weight of 2000 to 400 f)O and a sharp molecular weight distribution. This is because when the average molecular weight exceeds 40,000, the hardness of the photosensitive layer becomes low and printing durability cannot be expected.
If it is less than 2000, the darkening will increase and it will be impossible to obtain good properties.In addition, the sharper the molecular weight distribution, the lower the degree of crosslinking.
This is because a high charge retention ability can be obtained. (31 fat is (; when volatile components are 5()% solution, 25
It is preferable that the viscosity at °C is 200 to 3 f) (l fl cp. This is 30 f at 1 degree) fl c
If it is higher than ps, the dispersibility of the photoconductive material is poor;
This is because if it goes up or down by 0+1, the sensitivity will decrease and the coating properties will deteriorate, leading to defects and holes in the photosensitive layer.

The fluorine-containing polymerizable jl represented by the general formula flIl]
As a clear substance, 1 is hydrogen or a methyl group, I is a 77-alkyl group having 1 to 8 carbon atoms, preferably 1 to 1,
or 7) hydroxyalkyl J,% compounds can be suitably used. Particularly preferred heptad-containing 'ttfit
1,1.1-)trifluoroethyl acrylate, trifluoromethyl acrylate), I.

1.1-) Trifluoroethyl methacrylate, trifluoromethyl methacrylate, 1,1,1,2°2.3.
3-hebutafluorobutyl acrylate, 1,1-nofluoro-1-hydroxyethyl acrylate, li, I
, 2,2,3.3-heptafluoroacyl methacrylate, 1,1-nofluoro-1-hydroxyethyl methacrylate, and the like.

The (meth)acrylic acid esters and amides that can be used in the present invention may be the same as those copolymerized with the silicon-containing monomer.

In addition, if desired, '' having other polymerizable ethylene bonds
The t'-mer may be copolymerized with a oligoacid, for example up to 20% by weight.

The weight of the silicon-containing monomer in the heptadium-containing acrylic resin is 2 to 30% by weight, more preferably 3 to 30% by weight, based on the monomer weight.
Weight%.

The reaction between the fluorine-containing polymerizable I) polymer and (meth)acrylic esters (the same applies to amides and nitriles) may be carried out according to known methods such as solution polymerization and emulsion polymerization. Crotonic acid, maleic acid, itaconic acid, etc. may be added as an acid catalyst.

In accordance with the present invention, the commemorative silicon acrylic υ resin or heptadium-containing acrylic resin can be used as a binder for photoreceptors. Suitable examples include melamine resins commonly used as a component of the agent, such as butyl melamine cedar resin, methylated melamine resin, butylated benzoguanamine resin, methylated benzoguanamine resin, and epoxy resin.

Particularly preferred in heptylated melamine street fat is (:].

Resins other than these silicon-containing acrylic resins and hepta-containing melamine resins account for a small amount of 5-0 ()% of the total resin A, preferably If) = 5 + 1% by weight.

As a forming component of the insulating layer, 11! ! You can mix the ingredients. Lubricants are among the effective ingredients. As lubricants, vinyl heptanide, vinylidene fluoride, polystyrene, silicone resin, vinyl chloride,
Poly: +J4 fats such as fluorinated chloroethylene, neoprene, polypropylene, etc.

Raw wax, paraffin wax, synthetic wax, etc., oleic acid amide, stearic acid amide, lauric acid amide, heptalic acid amide, capric acid amide,
Fatty-1+-acid amides such as palmitic acid amide, metal stearate (Z n + M g ,
Ca.

K, Mn, etc.) salts, fatty acid metal salts such as oleic acid metal salts, lauric acid metal salts, phthalic acid metal salts, capric acid metal salts, carbons such as carbon fluoride and graphite, molybdenum such as molybdenum, molybdenum disulfide, etc. Examples of effective lubricants include boron chloride, metal carbonate (eg, silicon dioxide), etc.

In order to prevent the residual potential from increasing in the insulating layer, a charge transporting material or a low resistance organic compound may be added.

Charge transport materials include hydrazone type, oxadiazole type,
These are phenylmethane-based, pyrazoline-based, and styryl-based compounds. Examples of low resistance organic compounds include compounds such as 7-erocene and tetracyanoquinodimethane.

The thickness of the insulating layer is set according to desired characteristics.

Generally, when an insulating layer is attached mainly for the purpose of protecting the photoreceptor, durability, dark decay characteristics, etc., the insulating layer is set to be relatively thin, and it is provided when the photoreceptor is used for a specific electrophotographic process. The insulating layer 12- is set relatively thick. Usually the thickness of the insulation layer is ()
, 1 to 100μI, especially (), 1 to 5()μI are suitable.

The photoconductive layer used in the present invention includes a layer coated with Se or Cds, a layer coated with a mixture of Cds, ZnO, and TiO2 with an insulating binder, polyvinylcarbazole,
Any of those coated with an organic photoconductive material such as acetracene or phthalocyanine, a mixture with an insulating binder, and a layered layer with a charge transport layer can be used.

Effects of the Invention The electrophotographic photoreceptor of the present invention has excellent sensitivity, printing durability,
Excellent wear resistance.

50 g of acrylamide, 1308 styrene, CH2=C in a reaction vessel with an internal volume of 5e equipped with a stirring rock and a cooler.
l-1-COOCH2CF3150B, cumene hydroperoxide 38, butanol 350B, and 3 g of L-dodecyl mercaptan were charged, and after refluxing, cumene hydroperoxide 18 was added. 18 tl of IOflg of formalin and methyl ethyl ketone were added to the thus obtained clear paste polymer solution with a non-volatile content of 48-50%.
1.5 g of ME water maleic acid was added. By reacting in this way for 3 hours, a colorless and transparent fluorine-containing thermosetting acrylic resin with a viscosity of 750 cps was obtained.

On the other hand, 173 parts by weight of cadmium carbonate was added to 0.6 parts by weight of cupric chloride.
In addition to an aqueous solution containing 8 parts by weight, hydrogen sulfide was blown into the C.
d5(Cu)·nCdCO3 was precipitated. This precipitate was separated in a furnace, washed with water, dried, crushed, and calcined at 250'C for 15 hours.
<n≦4) Photoconductive particles were obtained. This photoconductive particle 1
00 parts by weight, thermosetting acrylic resin (Acrydic A
405: produced by Tai Nippon Ink Co., Ltd.) and 230 parts by weight of toluene were sufficiently kneaded in a ball mill bot to uniformly disperse the photoconductive paint 7111! It was. The coating time of this photoconductive paint on an aluminum substrate is approximately 30
A photoconductive layer of μm0 was formed.

The surface of this photoconductive layer is coated with the aforementioned fluorine-containing acrylic 0 (fat 1).
0 parts by weight and melamine resin (Super Beckamine J82f
2 parts by weight of 1 (manufactured by Hi-Ippon Ink Co., Ltd.) were added and diluted with methyl isobutyl ketone to form an insulating layer with a thickness of 0.5 μm.

EXAMPLE The same polymerization procedure as in Example 1 was used to close the mower to obtain styrene 20 (ig, 1,1.1-) trifluoroethyl methacrylate 12 (1, 508 methyl methacrylate and 30 g of β-hydroxypropyl acrylate). Using this method, a thermosetting acrylic resin containing 7 nitrogen having a solid content of 50% and a viscosity of 20 o cps was obtained.

ε-type copper 7 russiania 16 parts by weight, I]-nonitylaminobenzaldehyde diphenylhydrazone 30 parts by weight,
Acrylic polyol (Takera 2A-F+12: Takeda Pharmaceutical Co., Ltd.) 36 parts by weight, epoxy resin (Epon 10
(manufactured by 17 Nijimol Kagaku? 1) and 30 parts by weight of a mixed solvent of methyl isobutyl ketone: cellosolve acetate (1:1) were thoroughly kneaded in a ball mill and dispersed uniformly to form a photoconductive paint. Prepared.

15- Apply this photoconductive coating onto an aluminum substrate and apply approximately 1
A photoconductive layer with a diameter of 0 μm was formed. The surface of this photoconductive layer is coated with 10 parts by weight of the aforementioned fluorine-containing thermosetting acrylic resin and a melamine resin (Super Beckamine J820: Dainippon Ink (
Co., Ltd.) was added, diluted with methyl isobutyl ketone, and applied to form an insulating layer with a thickness of 0.3 μm.

EXAMPLE A photoreceptor was prepared in exactly the same manner as in Example 2 except that 0.5 parts by weight of stearic acid amide was added to the thin insulating layer.

150 parts by weight of methyl methacrylate, 100 parts by weight of butyl acrylate, 40 parts by weight of d-methacryloxypropyltrimethoxysilane, and cumene in a reaction vessel with an internal volume of 5e equipped with a stirrer 19j and a heater. 3 parts by weight of hydroperoxide, 200 parts by weight of toluene and 1 part by weight of butyl acetate
00 parts by weight, heated and copolymerized to reduce the non-volatile content to 50 parts by weight.
% by weight of transparent silicon-containing acrylic resin was obtained. This O(
The viscosity of fat -16= is 1000 c1+s, and the molecular weight is 8 S (1(+).

10 parts of this silicon-containing acrylic resin was diluted with toluene and applied together with an acid catalyst to form a sanded insulating layer with a thickness of 0.5 μm on the photoconductive layer 1- of Example 2.

Example 5 - 2 parts by weight of N-ethylcarbazole-3-aldehydemethylphenylhydrazone was added to 10 parts by weight of the silicon-containing acrylic resin obtained in Example 4, diluted with toluene, coated, and cured to give approximately A 1 μm insulating layer was formed on the photoconductive layer of Example 2.

Example - 10 parts by weight of a thermosetting acrylic resin (Acrydic A405) and 2 parts by weight of melamine 4J (Super Beckamine J82 ('l) were added to the photosensitive layer 112 of Example 1 above.
It was diluted with toluene, applied, and cured to form an insulating layer with a thickness of 0.5 μm.

Comparative Example Two ε-type copper 7 0972710 parts by weight, []-noethylaminobenzaldehydonophenylhydrazone 30 parts by weight,
Acrylic polyol (Takerankutsu\7(12) 36 parts by weight, epoxy 411 resin (Epon I +-1117) 5
A conductive coating material was prepared by kneading 30 parts of a mixed solvent of 3 parts of 2 parts and 30 parts of methyl isobutyl ketone (cellosolve acetate) (+:1) for 1 minute in a ball mill to uniformly disperse the mixture. This photoconductive paint was applied to an aluminum substrate 1 to form a photoconductive layer of about 10 μm, thereby producing a photoreceptor.

Comparative Example 3 - The photoconductive layer of Comparative Example 2 was coated with the aforementioned acrylic polyol 10.
Parts by weight and 1.5 parts by weight of epoxy Cedar 1 fat were diluted with toluene and applied, and cured to form an insulating layer of 0.5 μm.

The obtained photoreceptor was subjected to powder image transfer type copying (Iku (EP-31f)).
:Incorporated into Mi/Ruta Camera Co., Ltd.), Example 1 and Comparative Example 1 were -(iKV corona discharge, the pond was "-6K
The surface potential V of the photoreceptor immediately after a corona discharge of V is initially applied to the surface of the photoreceptor. (V), exposure range E2 /1 required for the surface potential after exposure to decrease to 1/2 of the initial surface potential
(lt+x, 5ec) and the coefficient of friction were determined. In addition, the image crystallinity after copying 500 (1 sheet) was measured. The measurement results are shown in Table 1.

19-20- As is clear from Table 1, the photoreceptor of the present invention has excellent initial electrostatic properties, printing durability, and good cleaning properties.
The photoreceptor becomes life.

Claims (1)

[Claims] 1. In an electrophotographic photosensitive member having an insulating layer on the photoconductive layer, the insulating layer has the general formula: % formula %] [wherein R3 is hydrogen or a methyl group, R2 is Carbon number 1~
A silicon-containing acrylic fit containing as one component a silicon-containing polymerizable monomer represented by 1, in which the alkylene group of 8 and R3 each independently represent an alkyl group having a prime number of 1 to 8.
fat or general formula:% formula%11 In the formula, R1 has the same meaning as above and Rf has 1-8 carbon atoms
Polymerizability represented by 1 representing a heptafluorinated alkyl group or a heptafluorinated hydroxyalkyl group! iiY! , an electrophotographic photoreceptor containing a heptadium-containing acrylic resin as one component.