JPS5880642A - Image bearing material - Google Patents

Abstract

PURPOSE:To enhance durability against electrical and mechanical impacts and charge retention characteristics, etc., by using the surface insulating layer of a photoreceptor or a recording material consisting of 3 layers of upper, middle, and lower layers, each made of specified material. CONSTITUTION:The surface insulating layer of an image bearing material, such as photoreceptor or recording material, for retaining a toner image or an electrostatic image is composed of an upper layer made mainly of a thermoplastic resin soluble in organic solvents, a middle layer made mainly of an acrylic polymer soluble in org. solvents consisting of acrylic monomers and a hardenable resin, and a lower layer made mainly of a hardenable resin. Said upper layer is superior in surface lubricity, mold releasability, and moisture resistance, and improves surface durability, cleanability, and charge retentivity, said lower layer enhances mechanical strength of the whole insulating layers, and protects the photoconductive layer, and said middle layer strongly unites the upper and lower layers.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an image holding member for holding toner ms.

Electrostatic or toner images are formed by various processes. Image holding members on which electrostatic images or toner images are formed include i-holding members having a photoconductive layer, which are called electrophotographic photoreceptors, and image holding members having no photoconductive layer. An image-bearing member usually consists of a support and an image-bearing layer thereon.

Electrophotographic photoreceptors have various configurations in order to obtain predetermined characteristics or depending on the type of electrophotographic process to which they are applied.A representative example of electrophotographic photoreceptors is a Km-retaining layer on a support. There are photoreceptors on which a photoconductive layer is formed, and photoreceptors with a laminated layer of a photoconductive layer and an insulating layer thereon as an image-retaining layer, which are widely used and consist of a support and a photoconductive layer. The photoreceptor is manufactured by the most common electrophotographic processes, namely charging, image electrophotography and development, j!
For good and bad light bodies, this insulating layer is used for image formation by transfer according to requirements 11'. This insulating layer protects the photoconductive layer and improves the mechanical strength and dark decay characteristics of the photoreceptor. It is provided for purposes such as improving O or being used in a specific electrophotographic process. Typical examples of electrophotographic processes using such a photoconductor having a surface insulating layer or a photoconductor having an insulating layer include, for example, U.S. Pat.
Publication No. 15446, Special Publication No. 15446, Special Publication No. 15446, Special Publication No. 1977-
They are described in Japanese Patent Publication No. 3713, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, Japanese Patent Publication No. 19747-1974, Japanese Patent Publication No. 4121-1974, and the like.

A predetermined electrophotographic process is applied to the electrophotographic photoreceptor to form an electrostatic image, and this electrostatic image is developed and visualized.

A typical structure of an image holding member without a photoconductive layer is one having an insulating layer as the image holding layer, and some typical uses of this image holding member are explained below. (1) For example, as described in Japanese Patent Publication No. 32-7115, Japanese Patent Publication No. 32-8204, and Japanese Patent Publication No. 43-1559, electrophotographic photoreceptors are The electrostatic image formed is transferred to an image holding member without a photoconductive layer and developed.
The toner image is then transferred to a recording medium. An image holding member used in this electrophotographic process. 4(2) Also, the tin *@! formed on the electrophotographic photoreceptor. Other electrophotographic processes for forming an electrostatic image on an image holding member without a photoconductive layer in accordance with the above are, for example, Japanese Patent Publications No. 45-30320, Japanese Patent Publication No. 48-5063, and Japanese Unexamined Patent Application Publication No. 1983-1989. 34
As described in Publication No. 1, etc., an electrostatic image is formed on a screen-shaped electrophotographic photoreceptor having many minute openings by a predetermined electrophotographic process, and photoconductivity is generated through the static image. By performing corona charging treatment on an image holding member without a photoconductive layer, the ion flow of the corona is modulated to form an electrostatic image on the image holding member without a photoconductive layer, and this is used as toner development to form a recording medium. The image holding unit used in this electronic four-dimensional process includes the process of transferring images to form the final image. (3) In addition, a toner image formed on an electrophotographic photoreceptor or an image holding member without a photoconductive layer by another electrophotographic process is directly transferred to a recording body, and then another photoconductive layer is added on the surface. Then, the toner image is transferred from the other image holding member to a recording medium and fixed. An image holding member used in this electrophotographic process. This process is highly effective for forming color images or for high speed copying. Recording media are usually highly flexible, such as paper or film, and as a result,
In addition to transferring the three-color image to a recording medium while accurately aligning the image, the three-color image is transferred to an image/holding member that can be formed from a material that hardly causes deformation, and this is recorded all at once. A more accurately aligned color image is formed when the toner image is transferred to the recording medium.In addition, transferring the toner image to the recording medium via the image holding member is effective for increasing the speed of copying. o (4) As another process, an electric signal is applied to a multi-needle electrode to form an electrostatic image in accordance with the electric signal on the surface of an image holding member that does not have a photoconductive layer, and this is developed. It is possible to make an image by Image holding member O used in this electrophotographic process The image holding member used in electrophotography is subjected to corona charging treatment,
Since it is subjected to various electrical and mechanical shocks during development processing, cleaning processing, etc., it is easily damaged. Once the image holding member receives a horizontal scratch, the quality of the image formed will deteriorate significantly.Therefore, there is a strong demand for an image holding member that has excellent electrical and mechanical impact resistance, charge retention properties, etc. 0
However, it has not been easy to provide an image holding member with such excellent characteristics.

Therefore, the main object of the present invention is to provide an image holding member with excellent durability.

The present invention provides an image holding member that holds an electrostatic image or a toner image. It consists of three layers: an intermediate layer mainly composed of a polymer and a curable resin, and a lower layer mainly composed of a curable resin. This is a special holding member characterized by having an i-edge layer.

The upper NI constituting the insulating layer of the retaining member according to the present invention is an organic solvent-soluble thermoplastic resin, and has excellent surface lubricity, mold releasability, moisture resistance, etc., and durability on the surface of the insulating layer. Achieves good characteristics in terms of cleanability and charge retention. In addition, the lower layer of the insulating layer is mainly formed of a curable resin, and the mechanical strength of the entire insulating layer is
Prevents indentation of the photoconductive layer due to mechanical impact and maintains the photoconductive layer. In addition, the intermediate layer, which is mainly composed of an organic solvent-soluble acrylic polymer made of acrylic monomers and a curable resin, has the effect of strongly integrating the upper and lower layers, resulting in improved durability as a whole. In particular, in the present invention, the effect of the intermediate layer is remarkable) and contributes to the good characteristics of the photoreceptor. When the upper layer and the lower layer are laminated face-to-face, the adhesion strength between the two layers is not sufficient, and the durability of the photoreceptor is impaired due to peeling between the two layers, but thermoplastic acrylic polymer By interposing an intermediate layer that is a mixed layer of curable resin and curable resin, the problem of poor adhesion strength is completely solved, and the features of the upper and lower layers effectively contribute to the durability of the photoreceptor. do. The organic solvent-soluble thermoplastic resin used to form the upper layer is polyester.

Phenoxy, /listyrene, vinyl chloride, cellulose, vinyl acetate, vinyl chloride-vinyl acetate copolymer, /lyacrylic acid ester, /lyolefin.

Vinyl acetate-acrylic copolymerization, thermoplastic urethane/ Examples include.

As the acrylic polymer used for the intermediate layer, an acrylic polymer composed of multiple acrylic monomers is used. This is because it has excellent compatibility with the curable resin used in the intermediate layer and is stable as a resin. In particular, if the compatibility is poor, each resin will separate, resulting in (1) a loss of optical transparency; and (2) a decrease in the adhesion between the lower layer and the upper layer, or the storage stability of the liquid. As a characteristically busy middle class in terms of bad things? It is impossible to fully demonstrate the effect. Several inventions similar to the above-mentioned subject matter have been known in the past.

For example, in an intermediate layer composed of a halogen-based polymer and a curable resin, the decomposition of the resin by light or heat of the halogen-based polymer, and the hawp generated during decomposition. This is accompanied by deactivation of the curable resin due to hydrogen chloride. As a result, various problems may occur, such as loss of optical transparency, reduced adhesion, poor liquid storage stability, and poor coating properties. . Or polymers other than halon-containing polymers, even #f/
Various polymers are known, such as polyester polymers, cellulose polymers, and ether polymers, but none of them can exhibit sufficient properties over a long period of time because they decompose in water.Acrylic monomers Examples include olefinic monomers such as ethylene and butylene, or acrylate monomers such as methyl acrylate, methmethyl acrylate, butyl acrylate, and butyl methacrylate.
, and these olefin-based monos ff +, and acrylate-based monos! − are various derivatives of

It is also effective for the upper layer to contain a lubricant, if necessary, and a rounded surfactant to disperse the lubricant, if necessary, in order to further improve the surface lubricity.

As the lubricant, a powder with a lubricating effect is used as appropriate. Typical lubricants include 4-lyethylene, 4-lytedrafluoroethylene, polyethylene terephthalate, polyvinylidene fluoride, -C-nyl chloride, Examples include metal stearates, paraffin wax, talc, and other substances that are substantially insoluble in general solvents.The particle size of the lubricant is -10μ or less in terms of missing particle size and 5μ or less in % Ka. Good @The amount of lubricant added is set appropriately, but
Generally, 0.5 to 90 weights per weight, particularly 5 to 50 weights, is suitable.

Various types of surfactants may be used, but
% is effective for fluorinated surfactants.・Fluorinated surfactants are surfactants that are highly fluorinated and contain nine long-chain alkyl groups in their molecules.・Representative of fluorinated surfactants. For example, C11FIA80. ,NRCH2COOK,”
CsF, 7809. NRCH2CH20 (CM, CH2
0) mH (Ik-5, 1g1.15) CaF, 780jN (CH2CH20H20H) fi
C@F17RO(CH2CH20)n C1aFia(RO), n-! %! (ICI4F!
14(R-0)IRm-to2(1, etc.0) R represents an alkyl group such as methyl, ethyl, propyl, butyl, or an allyl group such as phenyl or naphthyl. Fluorine surfactant is 0.5 It is preferable that #i1 to 30% is included in the range of SO weight 0. The thickness of the upper layer is set as appropriate, but is usually 40 to 2μ.
In particular, a range of 20 to 4μ is preferred.

The curable resin forming the intermediate layer and the lower layer is a resin that is cured by heat, light, electron beam, etc. In the case of thermosetting,
Particularly suitable curable resins that can be cured at room temperature depending on the type of resin include acrylic resin, urethane resin, /lyester resin, polyurethane resin, meladen resin, silicone resin, and the like.

The intermediate layer is formed mainly of an organic solvent-soluble acrylic polymer and a curable resin, but the mixing ratio of both resins affects the adhesive strength between the upper layer and the lower layer and the use of the upper layer when forming a coating film. Although 4O is appropriately set in consideration of the solvent resistance to the solvent used and the compatibility of both resins, the mixing ratio (weight ratio) of organic solvent-soluble acrylic polymer: curable resin is usually + , 8:2 to 0.5:9.5, especially 7:3 to 1:
A range of 9 is preferred.

The thickness of the intermediate layer is set appropriately, but it is usually in the range of 3-5 to 1 μm. The organic solvent-soluble alyl polymer and curable resin used to form the intermediate layer are in the upper layer. The same kind of heat as that used for the layer and the lower layer may be different, or it may match. Bottom layer. The thickness is also set appropriately, but usually 2
0 to 2 μ, and 41 is preferably set in the range of 15 to 47110. Forming an insulating layer by applying 0 is superior to bonding an insulating film to form an insulating layer). . Furthermore, when coating is used, a seamless edge layer can be formed on a tfch, )P ram-shaped image holding member. When the image holding member is an electrophotographic photoreceptor, the most typical structure is a laminate in which the photoconductive layer is between a support and an insulating layer. The support is made of any material such as stainless steel, steel, aluminum, tin or other metal plates, paper, or resin film.

A support is a must! ! omitted depending on the situation.

The photoconductive layers are s, s·, pbo, and s, s·, T·.

Formed by vacuum deposition of an inorganic photoconductive material such as an alloy or intermetallic compound having 4S, GB, etc. When using the 9-tuttering method, ZmO, Cd8, C118@*
A high melting point photoconductive material such as TlO2 can also be deposited on the support to form the photoconductive layer. In addition, when forming a photoconductive layer by coating, organic photoconductive materials such as polyvinyl cal/sol, anthracene, phthalocyanide, and those subjected to Lewis acid sensitization during dye sensitization, as well as their insulating properties and A mixture with a binder may be used. Also ZnO
Mixtures of inorganic photoconductors such as , CdS, TlO2, PbO, etc. with insulating binders are also suitable.Suitable insulating binders include various resins.6 The thickness of the photoconductive layer depends on the photoconductive material used. Depending on the type and characteristics of the film, a suitable value is 5 to 100μ for a single loss, and 10 to 50μ for a failure.Another resin layer may be interposed between the insulating layer and the photoconductive layer. . Other effective resin layers include resin layers having acid groups such as cargexyl groups and sulfonic acid groups, such as vinyl acetate-acrylic acid copolymers, vinyl chloride-vinyl acetate-acrylic copolymers, etc. Sword Tarr/) J Marr.

Ethylene-acrylic acid copolymer, styrene-acrylic acid copolymer, butadiene-acrylic acid copolymer, α
, ω polybutadiene dicarboxylic acid.

These include vinyl acetate-ethylene sulfonic acid copolymer, styrene-ethylene sulfonic acid copolymer, and the like.

These resins can be made water soluble or water soluble by neutralizing with alkali. Dispersion as capped particles is generally possible.

In this case, volatile alkalis such as ammonia, methylamine, dimethylamine, trimethylamine,
Ethyl Anne, Jethyl Asin.

It is obtained by coating and forming a resin layer using triethylamine, etc., and then heating it above the boiling point temperature of the volatile alkaline substance to completely remove the alkali.The photoconductive layer is resistant to organic solvents. Furthermore, when the holding member does not have a photoconductive layer, the most typical structure is one in which an insulating layer is formed on a support.

When an insulating layer is attached with the main purpose of improving the retention, durability, and dark decay characteristics of a general Ksfa holding member, the insulating layer is set relatively thin, and when the holding member is used for a specific electrophotographic process, the insulating layer is set relatively thin. The insulating layer provided is relatively thick.

Usually the thickness of the insulating layer is 5 to 70μ, especially 10 to 5μ
15 parts of curable cyclized butadiene gum (trade name: C
BR, made by Nippon Gosei Gamu) and 1 part of diazo curing agent were added and stirred well, passed through a roll mill device with a 40-tone gap 5 times to mix CdS and the binder well, and then toluene solvent The viscosity was set to 800. CPS K was adjusted, and a 3051-length Mut drum support was immersed in this adjustment solution.
After pulling it up at a speed of 30 minutes and 4 hours, it was heat-treated at 150° C. for 30 minutes to harden it and form a photoconductive layer with a thickness of 50 μm.

Furthermore, on this layer, a photocurable acrylic ester resin (trade name: Aronix 8060, Toagosei Kagakuten) was formed using a dipping method to form a 15μ thick lower layer.
After curing by irradiating with a silver lamp for 2 minutes, an acrylic polymer (trade name Nijikuri Pase CMZ-2, Moshoku Kasei) and a light-curing Mhf acrylate ester resin (trade name : Aronix M8060, Toagosei) was mixed at a resin solid weight ratio of 1:1, the viscosity was adjusted to 50 CF2K with methyl ethyl ketone, and the viscosity was adjusted to 7μ by the dipping method.
A thick O coating film was formed and irradiated for 5 minutes with a 4kW mercury lamp to harden it to form an intermediate layer.Next, I was added as a lubricant to a methyl ethyl ketone solution of vinyl chloride-vinyl acetate co-polymer (trade name: ■CH). Litetrafluoroethylene (component + i & name nil fvxn L-2,.

A coating layer with a thickness of 7 μm was formed using a coating liquid made by dispersing powder (particle size: 0.3 μm) (manufactured by Daikin Industries, Ltd.) with a surfactant (product name: FC-431, manufactured by Sumira 3M) using Gale Milut. Formed by dipping method, dried at 75°C for 10 minutes,
Forming an upper layer0 The photoreceptor manufactured in this way is referred to as a photoreceptor (2).In addition, when manufacturing a photoreceptor I, the upper layer is formed without adding any lubricant or surfactant. The photoreceptor manufactured using the method is referred to as photoreceptor (■). In addition, when manufacturing photoreceptor I, the photoreceptor is manufactured without forming an intermediate layer (however, the thickness of the lower layer is 28 μm).
In addition, when manufacturing photoreceptor I, a chloride-vinyl acetate copolymer body (trade name: Bakelite VMCHLU, manufactured by C, C) and a light source are used as the intermediate layer. A composition of curable acrylic ester resin (trade name: Aroex M-8060 manufactured by Futaku Agosei Co., Ltd.) with a resin solid content ratio of 6=4 was added with 21 J! of 2-ethyl mantraquinone as a polymerization initiator, and the viscosity was 45.・Using PS methyl ethyl ketone solution, form a coating layer with a thickness of 7μ by dipping method,
The photoreceptor produced by irradiation with a 4kW mercury lamp for 3 minutes and curing is designated as ■.

These photoreceptors! ~l[K, −-order eDC charging, secondary AC static neutralization and simultaneous exposure, dry phenomenon due to full-surface irradiation e-toner, urethane) cleaning blade (hardness 70°C, angle to insulating layer surface 30°C, blade load 2.0 kg)
) As a result of evaluating the durability of photoreceptors I to ■ in an electrophotographic process consisting of cleaning treatment with K, it was found that photoreceptors I
Even after repeated application of the electrophotographic process 10,000 times, the insulating layer of the photoreceptor did not peel off, and the images formed were clear. Regarding the photoreceptor IIK, even after 60,000 repetitions of the electrophotographic process, the insulating layer did not peel off, and streak-like O scratches were formed on the surface of the insulating layer, resulting in the formation of capri. occurred in the image.

Regarding the photoconductor IK, the electrophotographic dets process is 3.0.
After repeated applications of 00110, the upper layer of the insulating layer partially peeled off, and toner adhered to those areas, making the image formed very unclear.

Regarding the photoconductor WK, the durability is relatively improved when compared to the photoconductor ■ and the seal, and it can be used up to tens of thousands of times.
Peeling of the upper layer of the insulating layer was observed. Example 2 Example! In the photoconductors 1 to 2, photoconductive layers 8...
/Produce photoreceptors I to ■ in accordance with 9. These photoreceptors ■~■ also have the same resistance/resistance as photoreceptor weight~y.
In addition, for the photoconductive layer, place 200# of 5-nine S--D (10vt) alloy in an evaporation dish, set the evaporation source temperature to 320°C, and use the substrate ( U drum) temperature 6
Vapor deposition was carried out for 40 minutes at 8°C and an internal vacuum of 1 x 10 torr to form a thickness of 65μ. Each photoreceptor was manufactured by forming an insulating layer of 9, and as a result, an improvement of five times or more in durability was observed compared to a photoreceptor manufactured without an intermediate layer.

Example 3 Lower layer two-light curing resin I oxyacrylic resin (product name: M
VVCf-We-4, manufactured by Dainichiseika Chemical Co., Ltd.) intermediate layer Niacrylic polymer (trade name Niacridic A308, manufactured by Dainippon Inc.) and photocurable urethane resin (trade name Nisonne,
Kansai Paint) 2 Mixing ratio (3 near) Solid content weight ratio upper layer: line -
Example 4 Lower layer: Light-curing acrylic urethane resin (product name: I4 Ylon-200) lubricant, I-lytetrafluoroethylene (product name: Lup4-2, manufactured by Daikin Industries) : Sonne, @N Paint II) Intermediate layer Niacrylic polymer (Product name: 〆Ianal BR
-90, - made by Sanmengshii Co., Ltd.) and photocurable Nyxy resin (
Product name: V-5502 manufactured by Dainippon Inc.) Mixing ratio (3 near) Solid content weight ratio upper layer = 4 riether resin (product name: PKHH, manufactured by Anyon Carbide) Lubricant: / +7 ethylene (2μ
Diameter) Surfactant: C3F17802NC2H! lCH3C
H20 (CH2CH20) 1 on Example 5 K1 cyclization on ht drum support (200φ x 500 pieces)
Ributadeene resin (Product name: CBRs Japan Goh, :/
(manufactured by Co., Ltd.) was diluted with toluene to a viscosity of 90 Q-, and a coating film with a thickness of 5 μm was formed by dip coating, and then cured by irradiation with a 4 kW mercury lamp for 5 minutes to form a lower layer. Furthermore, on top of this is an acrylic polymer (product name: Near Crypase CMZ).
-2, produced by Moshoku Kasei) and photocurable acrylic ester resin (trade name: Near 4X M-8060, produced by Toagosei)
A mixture of (2:8) by weight was diluted with methyl ether ketone to a viscosity of 40 ep-, coated, and photocured to form a film R2.
An intermediate layer of μ was formed.

Next, a chloride-vinyl-vinyl-vinyl-vinyl copolymer resin (trade name:
VMCH) 80 parts, 'l'J tetrafluoroethylene (
20 parts (trade name: Nilbrone L-2, 0, 3μ diameter), and 0.2 parts (weight: FC-431) of surfactant (trade name: FC-431)
An image holding member was manufactured by applying the dispersion of k) to form an upper layer having a thickness of 5 μm.

In the 7'w process, in which an electrostatic image is formed on the sample by modulating the roller discharge due to the formed electrostatic image, a dry developer and a urethane cleaning blade (hardness 70, angle i 30' with respect to the surface insulating layer of the sample, Blade pressure 2.0k
As a result of durability tests for development, transfer, and cleaning using the 1I), the friction coefficient was 0.90, the number of image holding parts rotated smoothly, and the image was good. Even after 150,000 rotations, the blade edge part O No wear or friction damage on the surface of the holding member was observed, and no delamination of the insulating layer was observed.

The process for determining the durability of an image holding member using a Cd8 screen photoreceptor is as follows.

A 30 μm thick photoconductive layer was adhered onto a stainless steel wire mesh (opening width approximately 50 μm) by spray coating.

The composition of the photoconductive layer is CdS powder (70 parts by weight)'J? An insulating layer with a thickness of 15 μm was formed on the photoconductive layer by spray coating and silicone resin (trade name: KR-255, manufactured by Shin-Etsu Silicon Co., Ltd.) (30 parts by weight) at 80°C for 15 minutes. Formed. Insulating layer wire curing agent (product name: CR-
15) containing silicone resin (product name: T8R-144)
, manufactured by Toshiba Silicon).

Claims (4)

[Claims] (1) In an image holding member that holds an electrostatic image or a toner image, an upper layer mainly made of an organic solvent soluble thermoplastic resin and an organic solvent soluble device made of an acrylic monomer are provided on the surface 'rk1 of the image holding member. An image holding member 0 characterized in that it has an insulating layer consisting of three layers: an intermediate layer mainly composed of an acrylic polymer and a curable resin, and a lower layer mainly composed of a curable resin. (2) The image holding member according to claim 1, wherein the insulating layer is formed on another resin layer. (3) An image holding member according to claim 1, wherein the insulating layer is formed on the photoconductive layer. (4) The image holding member according to claim 1, wherein the upper layer contains a lubricant.