JPS6120049A - Electrophotographic sensitive body - Google Patents

Abstract

PURPOSE:To improve adhesiveness and wear resistance by using an alkyl etherified melamine/formaldehyde resin alone or the compsn. contg. said resin as an intermediate layer between a photoconductor layer and conductive substrate layer. CONSTITUTION:A butyl etherified melamine/formaldehyde resin is optimum for the alkyl etherified melamine/formaldehyde resin to be used. The resin having <=1,500 number average molecular weight, 2-4 number of bound formaldehyde for each one melamine nucleus and 1-2 number of methyrol groups is more particularly preferable. A polymer and copolymer of a vinyl compd. such as, for example, acrylate and methacrylate contg. a hydroxyl group, acrylic resin and alkyd resin, etc. are usable as the curable resin which can react with the melamine resin. The conductive substrate having the conductive layer of <=10<10>OMEGAcm volume resistivity is preferable; for example, metallic plates consisting of aluminum, aluminum-other metal alloys, iron, steel, etc., metallic compd. plates consisting of indium oxide, etc. and conductive plastic plates provided with electrical conductivity are usable for the conductive substrate.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to an electrophotographic photoreceptor, and particularly to an electrophotographic photoreceptor suitable for a laser beam printer.

[Background of the invention]

In a mold-containing electrophotographic photoreceptor, a charge-generating layer is usually formed on a conductive support, and a charge-transporting layer is further formed on the charge-generating layer. Due to the solvent contained in the coating liquid, the binder resin of the charge generation layer is likely to be eluted, resulting in a problem of deterioration of electrophotographic properties, and this point had to be taken into consideration during production.

Furthermore, a method is known in which an intermediate layer is provided between the conductive support and the photosensitive layer for the purpose of improving the adhesion between the conductive support and the photosensitive layer and the charging characteristics of the photoreceptor.

JP-A-53-48531 describes a post-chlorinated olefin polymer having one or more atomic groups selected from carboxyl groups, acid anhydride groups, hydroxyl groups, and oxirane groups as an intermediate layer, and amino groups; Compounds having a plurality of one or more atomic groups selected from imino groups, methylol groups, alkyl etherified methylol groups, carboxyl groups, acid anhydride groups, hydroxyl groups, oxirane groups, and incyanato groups in one molecule. There are compositions consisting of the following.

On the other hand, JP-A-52-76037 discloses lacquer, polypeptide, casein, rosin ester, chlorinated rubber, nitrocellulose, acetyl cellulone, acetyl butyryl cellulose, ethyl cellulose, methyl cellulose, alkyd m fat, phenolic resin. , urea resin, melamine resin, furan resin, Vesicle 41 polyester resin, ebogishi resin, lincone resin, polyurethane resin, xylene resin, toluene resin, vinyl chloride resin, vinylidene chloride resin, vinyl acetate resin, acrylic resin, styrene resin,
Examples include fluororesin, polyvinyl alcohol, polyamide, polycarbonate, and the like.

Generally, when the intermediate layer is non-uniform, the light attenuation property, which is the main function of an electrophotographic photoreceptor, is degraded. In particular, in the case of organic electrophotographic photoreceptors, they are usually prepared by coating a solution dissolved in a solvent, but the intermediate layer dissolves or swells due to the solvent, and not only does the intermediate layer not function properly. , leading to deterioration of electrophotographic properties. Therefore, in order to make light perform its function as an intermediate ~, in this regard,
It was necessary to consider.

[Purpose of the invention]

An object of the present invention is to provide an electrophotographic photoreceptor with excellent adhesiveness and abrasion resistance (durability) using a resin composition having excellent solvent resistance.

[Summary of the invention]

The electrophotographic photoreceptor of the present invention has alkyl etherified melamine as an intermediate layer between the photoconductor layer and the conductive support layer.
The method is characterized by using a formaldehyde resin alone or a composition containing this resin (that is, containing a resin that can be cured by reacting with this resin).

In general, factors that determine the lifespan of electrophotographic photoreceptors, especially organic photoreceptors, due to long-term repeated use are factors other than corona discharge of the charge transport material and deterioration due to light, etc., as well as friction with paper (transfer paper) and developer. Examples include the occurrence of external damage caused by this and a decrease in film thickness due to wear. In particular, since the surface of an organic photoreceptor is mainly composed of a charge transport substance and a binder resin, the surface 61! The degree is small. Therefore, JQ1 wear and external scratches due to long-term repeated use are unavoidable, and are a major factor in reducing the service life. However, it has been known in the past to form a retaining layer containing resin as a main component on an organic photoconductor for the purpose of improving surface hardness. However, the conventional ones had drawbacks such as insufficient hardness and electrophotographic properties, particularly sensitivity, which were significantly reduced by the formation of the protective layer.

As a result of extensive investigation based on this fact, the inventors found that no @
Alternatively, by applying an alcohol-soluble melamine resin or a composition made of a melamine resin and a resin that cures with the melamine resin via an intermediate layer onto an organic photoconductor or a photoconductor using a combination of these, and curing the photoconductor. It was discovered that the above-mentioned problems could be overcome, and this led to the present invention.

(Melamine Resin) As the alkyl needle-formed melamine-formaldehyde resin used in the present invention, butyl ether-formed melamine-formaldehyde resin is most suitable. In particular, the number average molecular weight is 1500
As discussed below, a resin in which the number of bound formaldehydes per melamine nucleus is 2 to 4 and the number of methylol groups is 1 to 2 is desirable.

This resin can be used alone, but it can also be used in combination with a curable resin that reacts with the resin. This melamine resin or its combination with other resins is used as a binder resin for photoconductive materials when applied to charge generation layers and charge transport layers, but when used as other layers, melamine resins are used as binder resins for photoconductive materials. A single layer (a layer not containing a photoconductive substance) of a resin or a combination of a melamine resin and a resin may be formed.

Resins with number average molecular weights exceeding 1,500 have poor reactivity and must be cured at high temperatures, resulting in deterioration of electrophotographic properties.

If the number of bound formaldehydes per melamine nucleus exceeds 4, the reactivity is poor and it is difficult to obtain desired electrophotographic properties. In particular, when lamination is performed by coating, the resin in the lower layer (for example, charge generation layer) is eluted, resulting in surface defects in the lower layer, leading to a decrease in photosensitivity. Conversely, if the number of bound formaldehydes per melamine nucleus is less than 2, the pot life of this mixture will be short when used in combination with other resins (that is, curable resins that react with this melamine resin). Become.

If the number of methylol groups per melamine nucleus exceeds two, the storage stability of this resin will be poor, and if it is dissolved in an organic solvent to prepare a coating solution for the light guiding layer, it will become cloudy during storage. It begins to occur. If there is less than one methylol group, the reactivity is poor, and the above-mentioned film surface defects are likely to occur during degradation.

In the butyl etherified melamine-formaldehyde resin, the bound formaldehyde is present as the above-mentioned methylol group, and mostly as a butoxymethyl group etherified with butanol, the number of which is:
The number is about 1 to 3 per melamine core. In addition, a small portion of bound formaldehyde is linked to bridging groups between melamine nuclei by condensation of methylol groups.

In this specification, the number average molecular weight is determined by gel permeation chromatography using a standard polystyrene calibration curve.

The method for producing butyl etherified melamine/formaldehyde resin is to dissolve melamine in butanol, drop formaldehyde thereto and carry out an addition and butyl [, -thylation reaction, or to dissolve melamine and formaldehyde in butanol and heat it. For example, methods include addition and etherification reactions. Here, the reaction is preferably carried out under acidic conditions (preferably pH 3 to 6) by adding an acidic catalyst such as nitric acid, hydrochloric acid, sulfuric acid, phosphoric acid, para-toluenesulfonic acid, etc., and the reaction temperature is set at the reflux temperature of butanol. Preferably, the temperature is about 90-100C. In addition, the amount of raw materials to be charged is 4 to 4 butanol per 1 mole of melamine.
Preference is given to using 5 mol and 3 to 7 mol of formaldehyde.

In addition, the number of bound formaldehyde, butyl ether groups, and methylol groups per melamine nucleus in butyl etherified melamine and formaldehyde resin may be determined by nuclear magnetic resonance (NMR) spectroscopy, but as follows. You can also ask for it. The number of bound formaldehydes can be determined from the difference between the charged amount and the unreacted formaldehyde determined by the sodium sulfite method. For the butyl ether group, add all internal standard substances to the reaction solution and determine the amount of butanol (unreacted butanol amount) in the reaction solution using a gas chromatograph.
This can be determined from liM subtracted from the amount of butanol charged. The methylol group can be determined by utilizing the number of butyl ether groups and from the area intensity ratio based on the butyl ether group and the methylol group in the NM spectrum.

(Resin suitable for use in combination with melamine resin) Examples of resins that can react with and harden with the melamine resin are conventionally known resins containing hydroxyl groups, such as vinyl compounds such as acrylic esters and methacrylic esters. Conventionally known polymers and copolymers, acrylic resins, alkyd resins, alkyd-modified alkyd resins, acrylic resins/alkyd-modified alkyd resins, modified crosslinked resins, vinyl-modified fluororesins, polyesters, and the like can be used. This,
These preferably have a hydroxyl value of 15 to 200 in order to react with the butyl etherified melamine/formaldehyde resin. The higher the hydroxyl value, the higher the curability, and the lower the hydroxyl value, the higher the water resistance.

The alkyd resin is a resin obtained by reacting, for example, a polyhydric carboxylic acid, a polyhydric alcohol, and, if necessary, oil or fat or resin acid. Examples of polyhydric carboxylic acids include phthalic acid, isophthalic acid, terephthalic acid, tetrahydrophthalic acid, maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, trimellitic acid, and pyromellitic acid.

These may be used in the form of ester-forming derivatives such as acid anhydrides and methyl esters. Polyhydric alcohol! :
I, terj ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol
dipropylene glycol, neopentyl glycol,
1.4-butanediol, 1.6-hexanediol,
Trimethylene glycol, glycerin, trimethylolpropane, trimethylolethane, pentaerythritol, etc.

Examples of the oil include tung oil, linseed oil, soybean oil, dehydrated castor oil, safflower oil, castor oil, coconut oil, and tall oil. The alkyd resin can be produced by a known method, and when oil is used, the oil and polyhydric alcohol are combined in the presence of an ester conversion catalyst such as lithium hydroxide.
After the reaction is carried out, the remaining polyhydric alcohol is added and the reaction is carried out at 180 to 250C, or when oil is not used, the raw materials are mixed and the reaction is carried out at 180 to 250C.

Acrylic resins include 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxyethyl acrylate, and 2-hydroxyethyl acrylate.
- It is obtained by copolymerizing α, β-ethylenically unsaturated monomers having hydroxy groups such as hydroxyethyl and 2-hydroxypropyl methacrylate, and other unsaturated monomers. Other unsaturated monomers include
α,β-monoethylenically unsaturated carboxylic acids such as acrylic acid, methacrylic acid, maleic acid, itaconic acid, methyl acrylate, ethyl acrylate, n-butyl acrylate,
Methyl acrylate bleached to 2-ethylhexynone,
α,/j-monoethylenically unsaturated force-saturated carboxylic acid kill esters such as n-butyl methacrylate; acrylamide intoxicants such as acrylamide, methacrylamide, N-methylolacrylamide, N-methylolmethacrylamide, diacetone acrylamide; Glycidyl esters of α,β-monoethylenically unsaturated carboxylic acids such as glycidyl acrylate and glycidyl methacrylate; vinyl esters of saturated carboxylic acids such as vinyl acetate and vinyl propionate; styrene, α-methylstyrene, and vinyltoluene. There are aromatic unsaturated monomers such as The above copolymerization is carried out in the presence of a radical catalyst such as azobisisobutyronitrile, benzoyl peroxide, dibutyl peroxide, carbon/hydroperoxide, etc.
This can be done by heating to 60C.

The alkyd resin-modified acrylic polymer can be obtained by polymerizing monomers that are raw materials for the acrylic resin in the presence of the alkyd resin.

The raw materials for the alkyd resin, acrylic resin, and alkyd resin-modified acrylic polymer have a hydroxyl value of 15 to 200.
It is preferable to adjust it so that In addition, if the hydroxyl value is too small, the curability will be poor, and if it is too thick, the water resistance of the coating film will be poor.

Furthermore, in the case where the charge transport layer is multilayered, the above-mentioned f/
The etherified melamine luminaldehyde resin may be combined with a conventionally known resin. That is, silicone resin, phenol resin, urea resin, furan resin, epoxy resin, silicone resin, vinyl chloride-vinyl acetate copolymer,
Xylene resin, toluene resin, urethane resin, vinyl acetate-methacrylic copolymer, acrylic resin, phenoxy resin, polymethyl methacrylate resin, polycarbonate resin, polyester-carbon copolymer, polyester resin, polyarylate resin, polyolefin resin ,
A charge transport layer is formed by using a known resin such as polyamide resin alone or in combination of two or more types as a binder resin, and then a charge transport layer is formed by using the above-mentioned butyl etherified melamine/formaldehyde resin as a binder resin. The transport layer can be formed in @ contact or via an intermediate layer.

It is desirable that the melamine resin and the above-mentioned resins are usually blended in a weight ratio of 5/95 to 50,150.

(Charge Generating Substance) The charge generating substance used in the present invention includes, for example, metal phthalocyanine, phthalocyanine pigment such as gold-free maple phthalocyanine, anthraquinone pigment, indigoid pigment, quinacrypan pigment, perylene pigment, polycyclic quinone pigment, methine squaric acid. Known materials such as pigments, monoazo and disazo pigments, selenium and selenium compounds, cadmium sulfide, zinc oxide, amorphous silicon and amorphous silicon compounds can be mentioned, and these pigments can be used alone or in combination of two or more.

(Charge Transport Substance) The charge transport substance used in the present invention is, for example, oxadiazole, triazole, imidasilone, oxazole, pyrazoline, imidazole, imidazolidine, pen/
Examples include dithiazole, benzoxazole, triphenylamine, and derivatives of these substances, and these charge transport substances can be used alone or in combination of two or more types.

(Catalyst, Organic Solvent) A catalyst such as hydrochloric acid, phosphoric acid, para-toluenesulfonic acid, etc. may be added to the thermosetting resin composition related to the butyl etherified melamine formaldehyde resin. The amount used is preferably 1 weight percent or less based on the butyl etherified melamine/formaldehyde resin.

The thermosetting resin composition of the above-mentioned butyl etherified melamine e-formaldehyde resin is suitable for use with organic solvents such as various alcohols such as xylene, toluene, butyl cellosolve, ethyl cellosolve, n-butanol, isobutanol, isopropanol, and methanol. It is used as a solid content.

(Conductive support) The conductive support preferably has a conductive layer with a volume resistance of 1010 Ωm or less, such as aluminum, aluminum-other metal alloys, steel, iron, lead, copper, etc. metal plates, tin oxide, oxide, etc. Metal compound plates such as indium, 81 iodide (CuI), and chromium oxide, conductive plastic plates, and plastics, paper, glass, etc. that have been made conductive by steaming or sputtering can be used. n
These supports may be cylindrical, sheet, etc., and are not limited to any shape.

(Application of the above melamine resin to the charge transport layer (1)) When a melamine resin is applied to the charge transport layer, the concentration of the charge transport substance is desirably 90% or less, particularly 70% or less. Further, there is no restriction at all even if the charge transport layer is formed on the conductive support side of the photoreceptor and the charge generation layer is formed on the surface side. In addition, it can be used as a film-forming aid or sensitizing aid to improve film-forming properties when forming a charge transport layer, or as a dye or pigment to increase or decrease a desired wavelength range, or to improve various electrophotographic properties. There are no restrictions on the addition of various additives such as auxiliary agents that impart . Furthermore, conventionally known techniques can be used for the protective layer formed on the photoreceptor.

Further, the binder resin in the charge transport layer must be at least partially crosslinked after curing, but the curing conditions are not limited in any way. Preferably, the binder resin composition is one that hardens at a temperature equal to or lower than the melting point of the charge transport material plus 200.

The charge transport layer may be formed in one layer or in multiple layers. When forming multiple layers, the coating method for each layer may be the same or different, and known coating methods can be used. In addition, when forming multiple layers, there are no restrictions on the types of binder resins, charge transport substances, etc. for each layer, and the addition of various film-forming aids and aids that impart effects on electrophotographic properties. It is not something that will be done. It is desirable that the concentration of the charge transporting substance contained in each layer is made smaller as the outer rm (surface side root) increases. In particular, if the concentration of the charge transporting substance in the outermost layer is small, the effect as a protective layer is significantly exhibited. Further, it is preferable that each charge transport material is of the same type.

Next, a typical example of a method for forming a charge generation layer and a charge transport layer on a conductive support will be described.

First, the charge generation layer is prepared by thoroughly mixing and stirring an organic solvent such as tetrahydrofuran, ethyl acetate, acetone, methyl ethyl ketone, halogenated hydrocarbon, etc. that can disperse the charge generation substance well or dissolve the resin and additives used as necessary. Adjust the coating liquid of the charge generating material. The conductive support is immersed in this liquid, or this liquid is dropped onto the conductive support and coated using a bar coater, roll coater, applicator, casting method, dipping method, etc. It is formed by drying or crosslinking reaction. As the resin, a known three-dimensional curing resin or thermoplastic resin can be used. The charge transporting layer is prepared by (1) mixing and stirring a charge transporting substance and a known binder resin in a known organic solvent to dissolve the mixture, and then adding various auxiliary agents to prepare a coating solution. The coating liquid is used to form charge transport (1) on the charge generation layer. (2) forming a charge transporting layer by coating the charge transporting layer alone on the charge generating layer with a coating liquid in which the charge transporting substance, the butyl etherified melamine/formaldehyde resin and each glazing aid are dissolved in a known organic solvent; Alternatively, repeat coating knee curing using this coating liquid to form a multilayer charge transport layer, or use this (2) liquid to coat the charge transport layer (1) formed in (1) above. By doing so, it is possible to form multiple charge transport layers having different binder resins. When forming a large amount of charge transport layer, the known percentage as mentioned above may be used.
Two or more ILM transport substances may be used in combination or may be different for each coating liquid or for each layer, but it is preferable to use the same substance. As the coating method, known techniques such as a bar coater, a roll coater, an applicator, a casting method, and a dipping method can be used. Further, after coating, the charge transport layer can be dried or cured by conventional methods such as heat and light.

Raba using the melamine resin of the present invention as a binder,
The layers for charge transport can be directly bonded to each other, and the charge generation layer and the charge transport layer can also be bonded to each other at 11 points.

(Application of the above-mentioned melamine resin to the charge generation layer) The charge generation layer is usually prepared by coating, so the charge generation substance, the above-mentioned binder resin, a bath agent and, if necessary, leveling are applied. A coating liquid consisting of agents and the like is prepared, applied using a bar coater, applicator, spray, dipping, etc., and then subjected to a drying (curing) process.

Blend INj of a charge generating substance and a consolidating agent resin (melamine thread resin alone or a composition containing this resin), the former/latter overlap ratio is 1/0.2 to 115 <, 11
When the latter is less than 0.2, the adhesive force with the conductive support decreases, and when a charge transport layer is formed, it tends to be easily peeled off from the conductive support.

Furthermore, if the latter content exceeds 115, the properties as a photoreceptor for electrophotography, that is, the photosensitivity, tend to deteriorate.

The thickness of the charge generation layer is usually 10 μm or less, particularly preferably 3 μm or less.

A composite type electrophotographic photoreceptor is obtained by forming a charge transport layer on the charge generator thus obtained. The charge transport layer is usually formed by coating, as in the case of the charge generating layer. , spraying, dipping, etc.

The binder for the charge generation layer exhibits a remarkable effect when coating using the coating liquid for the charge transport layer, especially when coating is carried out by dipping.

When the melamine thread resin of the present invention is used as a binder, the charge generation layer and the conductive support layer can be directly bonded, and the charge generation layer can be bonded directly.

(Application of the above-mentioned melamine-based resin to the intermediate layer) A leveling agent may be included for the purpose of improving film-forming properties as a coating film as the intermediate layer.

The thickness of the intermediate layer is generally preferably 5 μm or less, particularly 1 μm or less; if it is 5 μm or more, it will adversely affect electrophotographic properties, particularly light attenuation, and photosensitivity will deteriorate.

The intermediate layer is produced by coating using a bar coater, an applicator, spraying, tipping, etc., and is baked at a predetermined temperature to form the intermediate layer.

The photoconductor 1- may be of the type f as long as it does not require the use of a binder resin. Further, when using a binder resin, it is not necessary to use a melamine resin. The photoconductive layer is formed on the intermediate layer by any suitable means such as evaporation, sputtering or coating. In the case of coating, a coating liquid is prepared by adding a binder, a plasticizer, a sensitizer, and a solvent to the photoconductor, if necessary. The intermediate layer according to the present invention exhibits remarkable effects, particularly when this coating is used to form a photoconductor layer.

The intermediate layer may be located between the conductive support and the photoconductive layer, or between adjacent photoconductive layers in the case of two or more photoconductive layers.

(Application of the above-mentioned melamine-based resin to the pupil retention layer) A charge transporting substance can be contained in the protective layer if necessary, and the amount is preferably 30 or less. The thickness of the protective layer is not particularly limited and can be changed as necessary, but is preferably 20 μm or less. In addition, it is possible to add film-forming aids, sensitization aids, dyes and pigments that have the effect of increasing or decreasing the desired wavelength of light, or inorganic and organic fillers to the protective layer. can be added. Furthermore, although the resin forming the circulation layer of the present invention must be crosslinked after curing, the curing conditions are not restricted at all. When heat curing is carried out, it is preferable to carry out the curing at a temperature equal to or lower than the sum of the melting point of the material having the highest melting point among the charge transport materials used and 20C.

Next, the formation of pupil 1- will be described. A storage layer is formed directly or via an intermediate layer on a photoconductor layer consisting of a photoconductor layer or a charge generation layer and a charge transport layer on a tetraconductive support. The polymer used for the protective layer is the above-mentioned butyl etherified melamine/formaldehyde resin or a thermosetting resin composition that can be cured by reacting with the resin, such as xylene, toluene, tetrahydrofuran, ethyl acetate, acetone,
It is dissolved in a common organic solvent such as methyl ethyl ketone, halogenated hydrocarbon, various alcohols, or a mixed solvent thereof. The liquid may contain a charge transporting substance, various additives, etc., if necessary. This solution can be applied onto the photoreceptor described above using a known coating method such as a bar coater, a roll coater, an applicator, or an immersion method to form a protective layer. Solvent evaporation and curing reaction after coating can be carried out by conventional methods such as heating.

[Embodiments of the invention]

In the following description, parts and % indicate parts by weight and parts by weight, respectively.

(Production of butyl etherified melamine/formaldehyde resin) Production example 1 Weighed 126 g of melamine, 444 g of n-butanol, and 0.2 g of a 61-nitric acid water bath solution into a flask equipped with a stirrer, a reflux condenser, and a thermometer, and heated the mixture to 100C. After heating, 169 g of paraformaldehyde was added at equal intervals in 6 portions over 30 minutes, and then the mixture was allowed to react at reflux temperature for 30 minutes to remove moisture, and desolubization was performed so that the heating residue was 50 parts.

The viscosity at this time was (Gardna 25c)B.

Manufacturing example 2 126 g of melamine using the same equipment as in Production Example 1.

Take 296 g of n-butanol and 0.2 gv+ of 61% nitric acid and raise the temperature to 100C. Here n-butanol 14
A solution containing 169 g of 8 gi/C rose formaldehyde was added dropwise over 30 minutes using a dropping pump. Thereafter, the mixture was allowed to react at reflux temperature for 30 minutes to remove moisture, and then the heated residue was removed to the extent of 50 cm. The viscosity at this time was (Gardna/25tZ')H.

Production Example 3 Using the same equipment as Production Example 1, melamine 126g5"
- 444 g of butanol, 0.2 g of 61 nitric acid.

Furthermore, 169g of paraformaldehyde was mixed and prepared.
After raising the temperature to 100C, it was allowed to react for 30 minutes.

Furthermore, reflux dehydration was performed for 30 minutes to remove moisture, and
The solvent was removed so that the amount remaining after heating was 50 cm. The viscosity at this time was Gardner (25C).

Production example 4 Melamine 126g x n-butanol 370g.

112.5 g of paraformaldehyde was reacted in the same manner as in Production Example 1. The solution was removed by the time the heating residue reached 50 cm.

The viscosity at this time was (Gardna/25 tl:)C.

Production Example 5 Using the same equipment as Production Example 1, paraformaldehyde 2
17.5gX n-butanol 444g and melamine 1
26 g was taken out with a punch and an addition reaction was carried out at 90 to 100 C for 30 minutes. After that, it is cooled to 40-45C and phthalic acid is 0.
1 g was added, and reflux dehydration and dissolution were performed under acidic conditions. After this, the heating residue was adjusted to 60%. This product was adjusted with xylene so that the heating residue was 50 inches. The viscosity at this time was (Gardna/25C)B.

Production Example 6 Using the same equipment as Production Example 1, Varapolmaldehyde 3
10g, n-butanol 450g and melamine 130g
was weighed out and an addition reaction was carried out at 100C for 30 minutes.

Thereafter, the mixture was cooled to 40 to 45 C, 0.15 g of phthalic acid was added, and reflux dehydration and dissolution were performed under acidic conditions. After this, the heating residue was adjusted to vI4 so that it became 60 tons. This product was adjusted with xylene so that the heating residue was 50 inches. The viscosity at this time was (Guardboo/25c)B.

Production Example 7 The composition was the same as in Production Example 6 except for the addition of 590 g of n-butanol, and the production conditions were also the same as in Production Example 6.

Production example 8 It had the same composition as Production Example 1, and was reacted at 100° C. for 90 minutes.

Further, reflux dehydration was performed for 60 minutes to remove moisture and desolubilize so that the heating residue was 50%. The viscosity at this time was Gardner (25t?) and B.

Production Example 9 Using the same equipment as Production Example 1, rose formaldehyde 3
20 gXn-butanol 470 g and melamine 130 g
Weigh out the g, 90-100t? The addition reaction was carried out for 30 minutes. After that, cool to 40-45C and phthalic acid 0.1
5 g was added, and reflux dehydration and dissolution were continued under acidic conditions. For this grade, the heating residue was adjusted to 60 inches. This product was adjusted with xylene so that the heating residue was 50 inches.

The viscosity at this time was (Gardna/25r)B.

Production Example 10 Synthesis was carried out in the same manner as in Production Example 9, except for 590 g of n-butanol, with the same composition as in YA Example 6.

Production Example 11 The same composition as Production Example 9 was used, and the reaction was carried out at 10011:' for 120 minutes. Further, reflux dehydration was carried out for 60 minutes to remove moisture and desolubilization was carried out so that the heated residue amounted to 50 pieces. The viscosity at this time was Gardner (25C) and B.

Butyl etherified melamine obtained in Production Examples 1 to 11
Table 1 shows the number of formaldehyde bound, the number of butyl ether groups, the number of methylol groups, and the number average molecular weight per melamine nucleus for the formaldehyde resin.

However, the number of bound formaldehyde is determined by measuring the amount of unreacted formaldehyde by the sodium sulfite method, and the number of butyl ether groups is determined by roll grouping by gas chromatography using a butanol charging cap and 1-butylbutanol as an internal standard solution. was determined from the number of butyl ether groups and the NMR spectrum. Further, the number average molecular weight was determined by gel permeation chromatography under the following measurement conditions using a standard polystyrene detection line.

〔Measurement condition〕

Column: Hitachi Chemical ■Product name, GELKO11,
-420, R-430, and R-440 3 pieces connected in series (number of theoretical plates: 17000 plates/piece) Solvent: Tetrahydrofuran flow rate, 1. T7 5g
0.1 g of 1 and 30% aqueous sodium hydroxide solution was taken out using a punch, the temperature was raised to 60°C, and an addition reaction was carried out for 30 minutes. The body was cooled to 40 to 45C, 0.3g of 61% nitric acid aqueous solution was added, and the mixture was reacted under acidic conditions at 65C for 60 minutes. after that,
After neutralization with an aqueous solution of 30% sodium hydroxide, desolubization was performed under reduced pressure. The residue after heating was adjusted to 50 g using isobutanol and isopropanol. The viscosity at this time was (Cardona/25C) and was A. In this way, a methylated melamine resin was produced.

Production Example 13 Using the same equipment as in Production Example 1, 126 g of melamine, 322 g of ethanol, 187.5 g of paraformaldehyde
, and 0.1 g of a 30% aqueous solution of sodium hydroxide were weighed out, heated to 60C, and an addition reaction was carried out for 30 minutes. After that, cool to 40-45C and 0.3g of 61% nitric acid aqueous solution.
was added and reacted under acidic conditions at 70C for 60 minutes. Thereafter, the mixture was neutralized with an aqueous solution of 30% sodium hydroxide, and desolubilized under reduced pressure. Thereafter, the heating residue was adjusted to 50% with inbutanol and impropatol. The viscosity at this time (Cardona/25C) was A″'C. In this way, an ethylated melamine resin was produced.

Production Example 14 Using the same equipment as Production Example 1, 126 g of melamine, 360 g of isopropanol, 18 g of paraformaldehyde
7.5g, and 30% sodium hydroxide aqueous solution 0.1g
was weighed, heated to 60C, and an addition reaction was carried out for 30 minutes. Thereafter, the mixture was cooled to 40 to 45 C, and 0.3 g of a 61% aqueous solution was added to react for 60 minutes at 70 tZ' under acidic conditions. Thereafter, the mixture was neutralized with an aqueous solution of IJ (30% hydrogen oxide) and desoluted under reduced pressure.

After this, I adjusted the amount with inbutanol and isopropanol so that the amount left after heating was 50 inches. The viscosity at this time is (
Cardona/25C) and was rated A.

In this way, a propylated melamine resin was produced.

Table 2 shows the properties of the alkyl etherified melamine formaldehyde resins prepared in Production Examples 12 to 14 above.

Example 1 To 4 parts by weight of the butyl etherified melamine/formaldehyde resin of Production Example 1, add 13 parts by weight of tetrahydrofuran to dissolve, and add 0.002 parts by weight of KP-323 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a leveling agent. The mixture was stirred to obtain a coating liquid for an intermediate layer. This coating liquid has a thickness of 100 μm and a dimension of 70X.
Coating was performed on 100+o+ square aluminum foil using an automatic applicator (manufactured by Tsukuyo Seiki Co., Ltd.), and 11
Baking was performed at 0C for 1 hour to form an intermediate layer (thickness 0.5 μm).
) was obtained. The obtained intermediate layer was immersed in tetrahydrofuran and methylene chloride for 2 minutes, and then the surface was wiped with gauze and the appearance was examined. The results are shown in Table 22, and there was no change in appearance at all.

Examples 2 to 5 Coating liquids were obtained by the same coating liquid preparation method as in Example 2, butyl etherified melamine/formaldehyde resin was changed to Production Examples 2 to 5, and intermediate coating liquids were obtained by the same method as in Example 37. A layer (film thickness O65 μm) was obtained.

The solvent resistance of the obtained intermediate layer was examined in the same manner as in Example 2. The results are shown in Table 3, and it was found that the product of Production Example 5 with a molecular weight exceeding 1500 was at risk of being immersed in the solvent.

Table 3 ○ No change △ Slightly immersed Example 6 45 parts by weight of tetrahydrofuran was added to 5 parts by weight of IJ-N-vinylcarbazole (Tubicol 210, manufactured by Anan Perfume Industry Co., Ltd.) and dissolved by stirring.

To 5 parts of this solution, 0.5 parts of a solution prepared by dissolving 1 part by weight of a polyester resin (Toyobo Co., Ltd., Pylon 200) as a plasticizer in 49 parts of tetrahydrofuran was added, and further 2.3-dichloro 0.15 parts by weight of -5-methyl-1,4-naphthoquinone was processed and dissolved by stirring. To this solution, 1 part by weight of a solution in which 3 parts by weight of an ε-type copper phthalocyanine pigment (manufactured by Toyo Ink Manufacturing Co., Ltd., Lionol Blue ES) was dispersed in 97 parts of toluene, and a Levelin agent (manufactured by Toshi Silicone Co., Ltd., DCIIPA) were added. ) 2 parts by weight dissolved in 98 parts by weight of tetrahydrofuran and 0.1 parts by weight of a solution and 3 parts by weight of tetrahydrofuran were added and thoroughly stirred to prepare a coating liquid of the photoconductor composition.

This coating liquid was applied on the intermediate layer obtained in Examples 1 to 5 and on the aluminum foil (without intermediate layer) in the same manner as in Example 1, and dried at 100 tZ' for 1 hour. An electrophotographic photoreceptor was obtained. The electrophotographic properties of the electrophotographic photoreceptor thus obtained were measured. The measurement was carried out using an electrostatic recording paper testing device (manufactured by Kawaguchi Electric Co., Ltd., model 5P-428) in dynamic mode with 5 kV corona charging for 10 seconds, left in the dark for 30 seconds, and then exposed to a tungsten lamp. . During this time, the potential on the surface of the photoreceptor is recorded,
Potential V after corona charging, Potential V after being left in the dark for 30 seconds
The half-reduced exposure amount (photosensitivity) Eso (txi) until so and Vao become 1/2 was read.

The results are shown in Table 4.

Table 4 Example 7 A 1 ton three-necked flask was equipped with a stirrer, a nitrogen inlet tube, a thermometer, and a reflux condenser. 24 in this flask
5 parts by weight of distilled and dried quinone was added and heated to 136C with a mantle heater while slowly flowing nitrogen. Next, 50 parts by weight of styrene, 85 parts by weight of methyl methacrylate, 1o.

A mixed portion of heavy parts of acrylic #R2-ethylhexyl, 25 parts by weight of oxyethyl methacrylate, and 5 parts by weight of tertiary-butyl peroxide was added over a period of 1 hour. The temperature was maintained between 136-140C by adjusting the mantle heater or blowing air, and the temperature was maintained between 136-140C for 2 hours after adding the monomer mixture before cooling. , an acrylic polymer solution was obtained. This solution had a heating residue coefficient of 50 and a number average molecular weight of 10,000.

After adding and mixing 6 parts by weight of the resin solution of Production Example 1 to 14 parts by weight of this resin solution, 30 to 18 parts by weight of tetrahydrofuran was added.
0 parts by weight and 0.01 parts by weight of KP-323 (manufactured by Shin-Etsu Chemical Co., Ltd.) as a leveling agent were added and stirred to obtain intermediate layer coating liquids having various positions. Using this coating liquid, intermediate layers having various thicknesses were coated in the same manner as in Example 1.

Next, a solution consisting of 1 part by weight of τ type metal-free phthalocyanine/(manufactured by Toyo Ink Manufacturing Co., Ltd.), 0.01 part by weight of KP-323, and 40 parts by weight of tetrahydrofuran was washed in an ultrasonic cleaner (Shinmeidai Kogyo Co., Ltd. IJ, UA). -100 type) for 1 hour to obtain a charge generation layer coating liquid.

This coating liquid was coated on the middle layer and on the aluminum foil without the middle layer using the same Hiko method as in Example 1.
C. After drying for 1 hour, charge-generated j- was obtained.

Next, polycarbonate (GE, Lexan 141) 2
After adding 25N parts of methylene chloride to 1 part of violet and dissolving it, 2 parts of charge transporting substance having the following structural formula, KP-
0.02 part by weight of 323 was added and dissolved to obtain a charge transport layer coating liquid. Using this coating liquid, coating was carried out in the same manner as in Example 1, and after drying at 100 C for 1 hour, a charge transport layer was formed to obtain an electrophotographic photoreceptor. The electrophotographic properties of this photoreceptor were examined in exactly the same manner as in Example 6, except that the corona applied voltage was changed to 05 k■. A cross-cut test was conducted to examine the adhesive strength between the 414L support and the light guide ILywI. The surface of the photoreceptor was cut into 100 squares at intervals of 11I111, and the number of squares remaining when peeled off with a Cero/Ntezo was evaluated.

Table 5 In this way, by providing an intermediate layer, the engagement force with the conductive support can be improved.

However, if the intermediate layer becomes thick, the photosensitivity decreases, so the thickness is usually 5 μm or less, particularly preferably 1 μm or less.

According to Examples 1 to 7, there was no elution of the intermediate layer during coating during the preparation of photoconductor I, and a photoreceptor with good electrophotographic properties was obtained.

〔Effect of the invention〕

According to the present invention, by using a new melamine resin composition having excellent solvent resistance, an NFC* photoreceptor with excellent adhesiveness and abrasion resistance can be obtained.

Claims (1)

[Claims] 1. An electrophotographic photoreceptor in which a photoconductor layer is laminated on a conductive support via an intermediate layer, characterized in that the intermediate layer is made of an alkyl etherified melamine/formaldehyde resin or a composition containing this resin. A photoreceptor for electrophotography.