JPS59159168A - Image bearing material - Google Patents

Abstract

PURPOSE:To enhance strength, durability, etc. by forming the insulating layer of an image bearing material holding an electrostatic image or a toner image consisting of the upper layer composed essentially of an org. solvent-soluble thermoplastic resin and the lower layer composed essentially of this resin and a photo-setting acrylic-modified epoxy resin. CONSTITUTION:An insulating layer formed on the photoconductive layer of an electrophotographic sensitive body or the insulating layer of a toner image bearing material having no photoconductive layer, etc. consists of the upper layer composed essentially of an org. solvent-soluble thermoplastic resin incorporating a highly fluorinated surfactant, etc., when needed, for uniformly dispersing a lubricant, and the lower layer composed essentially of said resin and a photo-setting acrylic-modified epoxy resin having 400-3,000 weight average mol. wt. and <=5 acid value, and a first/second resin mixing ratio of (10:90)-(70:30). As a result, the lower layer enhances adhesion strength between the photoconductive layer or a substrate and the insulating layer and mechanical strength of the image bearing material, and the upper layer enhances electrostatic charge retentivity, cleanability, etc. to extend its durability.

Description

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

Electrostatic or toner images are formed by extreme processes. Image holding members on which electrostatic images or toner images are formed include image holding members having a photoconductive layer and image holding members not having a photoconductive layer, which are called electrophotographic photoreceptors. 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. Typical electrophotographic photoreceptors include a photoreceptor in which a photoconductive layer is formed as an image-retaining layer on a support, and a photoreceptor having a laminate of a Hikari 24 layer as an image-retaining layer and an insulating layer thereon. The body is widely used. The photoreceptor, consisting of a support and a photoconductive layer, is used for imaging by most common electrophotographic processes, ie, charging, imagewise exposure and development, and optionally transfer.

For photoreceptors equipped with an insulating layer, this insulating layer may be used for purposes such as protecting the photoconductive layer, improving the mechanical strength of the photoreceptor, improving dark decay characteristics, or being applied to certain electrophotographic processes. It is established for the purpose of Representative examples of photoreceptors having such an insulating layer or electrophotographic processes using a photoreceptor having an insulating layer are, for example, U.S. Pat.
Publication No. 9, Special Publication @38-15446, Special Publication No. 1973
-3713 Publication, Japanese Patent Publication No. 42-23910, Japanese Patent Publication No. 43-24748, Japanese Patent Publication No. 1974-19747
It is described in Japanese Patent Publication No. 36-4121, etc.

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 configuration of an image bearing member without a photoconductive layer is one having an insulating layer as the image bearing layer, and some typical uses of this image bearing member are described below.

(1) For example, Japanese Patent Publication No. 32-7115, Japanese Patent Publication No. 3
As described in Japanese Patent Publication No. 2-8204 and Japanese Patent Publication No. 43-1559, an electrostatic image formed on an electrophotographic photoreceptor is coated with a photoconductive layer for the purpose of improving the repeatability of the electrophotographic photoreceptor. The toner image is transferred to an unsupported image holding member and developed, and then the toner image is transferred to a recording medium. An image holding member used in this electrophotographic process. (2) In addition, as another electrophotographic process in which an electrostatic image is formed on an image holding member without a photoconductive layer in correspondence with an electrostatic image formed on an electrophotographic photoreceptor, for example, Japanese Patent Publication No. 45-30320 As described in Japanese Patent Publication No. 48-3063, Japanese Unexamined Patent Publication No. 51-341, etc., a screen-shaped electrophotographic photoreceptor having a large number of minute openings is coated by a predetermined electrophotographic process. By forming an electrostatic image and applying corona charging to an image holding member that does not have a photoconductive layer via this electrostatic image, the ion flow of the corona is modulated and the electrostatic image is transferred to the photoconductive layer. An example of this process is to form a final image on an image holding member that does not have an image, develop it with toner, and transfer it to a recording medium. An image holding member used in this electrophotographic process. (3) According to other electrophotographic processes, the toner image formed on the electrophotographic photoreceptor or image holding member without waiting for the photoconductive layer is not transferred directly to the recording medium, but is further coated with another photoconductive layer. Transfer it to an image holding member that does not have it,
Next, the toner image is transferred from this image holding member to a recording medium and fixed. An image holding member used in this electrophotographic process. This process is useful for forming color images or for high speed copying. Recording media are usually highly flexible, such as paper or film, and for this reason, it is better to transfer a three-color image onto a recording media while accurately aligning the material, which causes almost no deformation. A more accurately aligned color image is formed by transferring a three-color image to an image holding member that can be formed using a three-color image holding member, and then transferring the three-color image to a recording medium at once. Furthermore, it is effective for speeding up copying that the toner image is transferred to the recording medium via the image holding member. (
4) In addition, as another process, multi-needle, -electrode 1
G is applied to form a static image in response to an electric signal on the surface of the mound holding part which does not have a light guide layer, and this can be developed to form an image.

Image holding members used in electrophotography are 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 is damaged, the quality of the image formed will be significantly reduced. Therefore, there is a strong desire for an image holding member that has excellent electrical resistance, mechanical impact resistance, charge retention, and the like. However, it has not been easy to provide an image holding member with such excellent characteristics.

For this reason, conventionally, the insulating layer has a three-layer structure, the upper layer has good properties in terms of durability, cleanability, and charge retention on the surface of the insulating layer, and the lower layer is made of a curable resin with high mechanical strength. Prevents and protects the photoconductive layer from indentation due to mechanical impact. Furthermore, it has been proposed that the intermediate layer has the function of an adhesive layer for bonding the upper layer and the lower layer, and that the entire layer functions as one insulating layer.

However, when this method is used, the production process is complicated, which increases the burden in terms of production management and production equipment, which results in high costs.

As the number of processes increases, the rate of defective products increases.

Due to the large number of adhesive surfaces, there is a risk of delamination in the event of mechanical impact.

There are drawbacks such as:

It is an object of the present invention to provide an image holding member that has performance equivalent to or better than an image holding member having a three-layer structure shown in θσ in terms of durability, and is better in terms of limb equipment, management, cost, and productivity. The main purpose is to
-The static electricity is 1%! In the image holding member that holds the toner image, the upper layer of the image holding member (in addition, the upper layer mainly composed of an organic solvent soluble thermoplastic resin and an organic solvent soluble thermoplastic resin and a curable resin) is used. This image holding member is characterized in that the curable resin used for the lower layer is a photocurable acrylic modified Epoquine resin.

The upper layer constituting the insulating layer of the image-holding shrine according to the present invention is an organic solvent-soluble thermoplastic resin, and has excellent surface lubricity, mold releasability, moisture resistance, etc., and has durability on the narrow surface of the insulating layer. sex,
Achieves good characteristics in terms of cleanability and charge retention. The lower layer of the insulating layer is made of an organic solvent-soluble thermoplastic resin and a photocurable acrylic-modified epoxy resin. In addition, it prevents the photoconductive layer from being indented due to mechanical impact and preserves the photoconductive layer.

Further, the presence of the thermoplastic resin component has the effect of strengthening the adhesion with the upper layer of the image holding member and integrating it.

If a thermoplastic resin is not present, the adhesive strength between the upper layer and the lower layer will not be sufficient, and the durability of the photoreceptor will be impaired due to peeling between the two layers. As a result, the problem of poor adhesive strength is completely solved, and the features of the upper and lower layers effectively contribute to the durability of the photoreceptor.

The thermoplastic resin used for the upper layer of the image holding member includes:
Polyester, phenolic acid, polystyrene, vinyl chloride, cellulose, vinyl acetate, vinyl chloride x molten vinyl copolymer, polyacrylic cough ester? Suitable examples include lyolefin, vinyl acetate niacryl copolymer, and thermoplastic urethane.

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

As the lubricant, powder having a lubricating effect is appropriately used. Typical lubricants include polyethylene, polytetrafluoroethylene, polyethylene terephthalate, polyvinyl fluoride, polyvinyl chloride, stearin, graphene wax, and talc, which are virtually incompatible with general solvents. Examples include bath-based ones. The particle size of the lubricant is −
A secondary particle size of 10 μm or less, particularly 5 μm or less is preferable. The amount of the decoy lubricant to be added is appropriately set, but it is usually 0.5 to 900 degrees, preferably 5 to 50 degrees.

Various types of surfactants may be used, but
Particularly effective are fluorosurfactants. Fluorine surfactants are surfactants that contain highly fluorinated long-chain alkyl groups in their molecules. Examples of fluorosurfactants include C3F17So2. NRCH2GOOK.

05F, 7RO (CH2CH20) n c 1 b p sa (RO) n n -5~
z.

C, 6F34(Ro)nRn-5-20, etc.

Rid represents an alkyl group such as methyl, ethyl, propyl, butyl, an allyl group such as phenyl or naphthyl, etc.

The fluorosurfactant is preferably contained in a range of 0.5 to 50% by weight, particularly 1 to 30% by weight. The thickness of the upper layer is appropriately set, but is usually in the range of 40 to 2 microns, particularly preferably in the range of 20 to 4 microns.

The thermoplastic resin forming the lower layer includes polyesterphenooxine, polystyrene, FjAft=vinyl, cellulose, vinyl acetate, vinyl chloride=vinyl rnate copolymer, polyacrylic ester, polyolefin, vinegar 1-wave vinyl-acrylic copolymer. Coalescence, polyvinylidene styrene chloride = 7-acrylonitrile copolymer, solubilized vinylidene--acrylonitrile copolymer, thermoplastic urethane, acrylic, styrene-nibutalaene-acrylonitrile copolymer,
etc. are used.

Photo-curable acrylic modified epoxy resins forming F m /INN include bisphenol A M , halogenated bisphenol type, resorcinated bisphenol F type,
Tet-poor hydroxyphenylethane, novolac type,
Those having skeletons such as polyalcohol, polyglycol type, glycerin triether type, I-lyolefin type, alicyclic type, etc. are used, and have a weight average molecular weight of 400 to 3000.1.
A compound having a unitization ratio of 5 or less is suitable.

The mixing ratio of the thermal nJ plastic tsukusai and the photocurable acrylic modified epoxy resin in the lower layer is 10290 to 70:
A range of 30:30, particularly 25:5 to 60:40 is suitable.

When epoxy resin is used in a mixed yarn with thermoplastic resin,
After coating, when heated to remove volatile matter such as residual solvent, the thermoplastic resin component forms a film, but the epoxy resin component exists in an oligomer state among the thermoplastic resin components. When cured by irradiation, epoxy resin has extremely small reaction shrinkage force and good dimensional stability, so there is less distortion compared to other resins, and therefore it has excellent mechanical durability. Further, since the insulation resistance is high in the curable resin, the thickness of the insulating layer can be set relatively thin, and the resolution can also be improved.

The thickness of the lower layer is appropriately set, but it is usually preferably set in the range of 5 to 40 microns, particularly 10 to 25 microns.

The most typical structure when the image holding member is a Kameko photoreceptor is a laminate in which the photoconductive layer is between a support and an insulating layer. The support is formed from any material such as a metal plate such as stainless steel, copper, aluminum, or tin, paper, or a resin film. The support may be omitted if necessary.

The photoconductive layer is S) Sea pbo j and S, Ss,
Te.

It is formed by vacuum distilling a void-free photoconductive material such as an alloy containing As or Sb or an intermetallic compound. In addition, when using the sputtering method, ZnO,
A high melting point photoconductive material such as 'r102 can also be applied to the support to form a photoconductive layer. In addition, when forming a photoconductive layer by coating, organic photoconductive additives such as polyvinylcarbazole, antho2cene, phthalonanine, color sensitized or Lewis acid sensitized products of these, and insulating binders thereof are used. A mixture of the following can be used. Also Zn
Mixtures of inorganic photoconductors with insulating binders such as Or OdS p Tie2p PbO are also suitable. Note that each glaze resin is used as the insulating binder. light guide'r
ii: The thickness of the layer is generally 5 to 100 μm, particularly 10 to 50 μm, although it depends on the type and characteristics of the photoconductive material used.
degree is suitable. Furthermore, when the image holding member does not have a photoquadratic layer, the most typical h4 formation is one in which a k edge N'e is formed on a support.

Generally, when an insulating layer is attached for the main purpose of improving the retention, durability, and dark decay characteristics of an image holding member, the insulating layer is set relatively thin, and the image holding member is used in a specific electrophotographic process. The insulating layer provided in this case is relatively thick.

Usually the thickness of the insulating layer is 5 to 70μ, especially 10 to 5μ
Set to 0μ.

Example 7 1゜To 100 parts by weight of CdS powder (parts by weight, same hereinafter), 12 parts of vinyl chloride copolymer resin (A, product name: VMCH% manufactured by Union Carbide) was added as a binder, and further methyl ethyl ketone was added. After thorough stirring, the CdS and binder were thoroughly mixed by passing through a roll mill device with a 40μ gear 5 times, and then the viscosity was adjusted to 500 centivoise using methyl ethyl ketone. Soaked in adjustment solution, 50 am/m
After pulling it up at a speed of 100.degree. C., it was dried for 20 minutes at a temperature of 80.degree. C. to form a 35.mu. thick optical Sm layer. Furthermore, this was immersed in a bath solution in which cyclized butanoene rubber (trade name: CBR-M, manufactured by Nippon Gosei Com) was dissolved in cyclohexane and adjusted to a viscosity of 40 centipoise, and dried at 80°C for 20 minutes to determine the film thickness. A 7 μm thick layer was formed to serve as a sealing layer.

Next, on top of this, the original hardening type Actul modified epoxy first oil (trade name: Ultra 5./T; manufactured by Asahi Kame Kako Awa Co., Ltd.) and the hot-curing agent 'aJ bath-type thermoplastic styrene aJ Mix oil (trade name: Nisquilon 666; Asahi Daucho) in a ratio of 60 parts by weight to 40 parts by weight, add 2 parts of acrylic and quazonium catalyst, dilute with methyl ethyl ketone bath, 8 parts by weight.
81 (
W ultraviolet, ti! Cured by high pressure mercury run, 18
μ) Rix the early membrane. Furthermore, on top of this, polytetrafluoroethylene (product name: Esle, 7riA) was added as rLYj detergent. m A'o name Nilburon L-5; Daikin Industries (closed) powder (- missing grains q
: k 0.3 μm) was dispersed in a sand mill using an interfacial Y occupancy agent (trade name: Florado; Ranui M 3 M'JJ), and a 9 μm thick fallen Y5 film was precipitated using cloth liquid TJIi. It is formed by a dipping method and dried at 80° C. for 15 minutes to form an upper layer. The photoreceptor manufactured in this manner will be referred to as photoreceptor A.

When manufacturing photoreceptor A, a photoreceptor B is obtained in which the lower layer is formed only of JP + 7 resin without using styrene resin.

Furthermore, in photoreceptor B, a vinyl chloride-vinyl acetate copolymer resin (trade name: S-LEC A;
Sekisui Chemical (manufactured by Co., Ltd.) and a photocurable acrylic ester resin (product name: Aronix 8060; manufactured by Takuyasei Co., Ltd.) with an intermediate layer of 6 μm thick (however, the thickness of the lower layer is The photoreceptor C has a thickness of 12 μm.

For these photoconductors A to C, - next ■DC@electronic, secondary D
The electrophotographic process consisting of C charge removal and simultaneous exposure, full-surface irradiation, (2) dry development with toner, and cleaning treatment with a urethane rubber cleaning grade was repeated, and comparisons were made.

As a result, even after repeated use of the electrophotographic process 100,000 times in photoreceptor A, the photoreceptor insulating layer did not peel off and the images obtained were clear, and all other uninvented objectives were satisfactorily achieved. Ta.

In photoreceptor B, after repeated use of the electrophotographic process 10,000 times, the upper layer of the insulating layer partially peeled off, and problems with a solid layer of toner and a damaged tube occurred in those areas, resulting in incomplete images. It became something.

Regarding photoconductor CK, even after repeated application of electrophotographic Zorose 10 times, no abnormality was found on the photoconductor and the images obtained were clear, and when compared with photoconductor A, there was no difference between the two. Example 2 A 5e-Te photoconductive layer was used in place of the CdS photoconductive layer in the 5Th photoconductors A to C of Example 1 to produce a 5Th photoconductor 4 (~C').
was manufactured.

This C) (7) For t<photoconductor' to C', the same :flij durability as that of photoconductor A-B was observed.

In addition, 5e-Te light, lIt' 5 nine 5e-Te
(10wt%) Alloy 2003 was weighed into an evaporation dish, the evaporation source temperature was 320°C, and the substrate (At cylinder) temperature was 68°C.
℃, vacuum temperature in the system 1X10 torr for 40 minutes, and a film formed to a thickness of 65 μm was used.

Example 3 A photoreceptor was manufactured by forming an insulating layer having the following composition on the photoconductive layer manufactured in Example 1, and the same results as in Example 1 were obtained.

Upper layer two-dimensional polyester resin (product name: Vylon 20
0; manufactured by Toyobo) Lower layer thermoplastic resin: Vinylidene chloride = acryloni)
IJ copolymer resin (trade name, Safran X 202; manufactured by Asahi Dow) Example 4 Solvent-soluble thermoplastic polyethylene resin (trade name: P
KHH, manufactured by Union Carbide) 50 parts by weight, 50 parts by weight of photocurable acrylic modified epoxy resin (trade name: DU-5; manufactured by Toa Zein), and 21 parts of 2 ethyl anthraquino/as a cementing agent. Mix it with methyl ethyl ketone! A diluted solution of 18% was applied by dip coating, and 15% of the solution was applied at a temperature of 80°C.
After drying for 1 minute, apply 8 kW high-pressure ultraviolet light and a high-pressure lamp.
It is irradiated for minutes to form a coating film with a thickness of 30 μm, which is used as the lower layer. At this point, the photocurable resin has been cured, so the lower layer as a whole has solvent resistance. Even if a p upper layer is formed upwind of this layer by the dipping method, it will not be attacked.

Next, polytetrafluoroethylene (trade name Nilburon L-2; manufactured by Taikin Kogyo Co., Ltd.) was added to the Ioo portion of polysarpone resin (trade name Newdel, manufactured by Yasan Kagaku Co., Ltd.).
10 parts of Cβ1 as a fractional auxiliary material and 4 parts of 1crivinylbutyral as a fractional auxiliary were soaked in a bath IK dispersion of ethane dichloride.
5 and dried at 80°C for 15 minutes to form a 10μ thick film as the upper layer.

Using this image holding part, a silent image is formed on the sample by modulating corona discharge by electrostatic method formed on a CdS screen photoreceptor. In the 70 process, As a result of durability trials of development, transfer, and cleaning using an angle of 300 (blade pressure 2.0 kg) with respect to the sample insulating layer, the coefficient of friction was 0.90, and the image holding member rotated smoothly. The image was good. Even after using 10μ sheets, there was wear and tear on the blade esso part, and the image holding part remained on the moon surface.
No scratches were found, and the insulation layer was peeled off for ¥41 #I'! No border harvesting was observed. In addition, since only two layers of coating film were to be formed, it was possible to increase productivity in terms of productivity.

Claims (1)

[Scope of Claims] 1. An image holding member that holds an electrostatic image or a toner image, comprising an upper layer mainly composed of an organic solvent-soluble thermoplastic resin, an organic solvent-soluble thermoplastic resin, and a photocurable acrylic resin. An image holding member comprising an insulating layer with a lower layer mainly made of modified epoxy resin. 2 The photocurable acrylic modified epoxy resin has a weight average molecular weight of 400 to 3000, an acid value of 5 or less, resin, solvent =
Item 1 between A and 1 of the patent claim, characterized in that the mixing ratio of the J-molten thermal iJ plastic resin and the photocurable acrylic modified epoxy (gj resin) is in the range of 10:90 to 70:30. 3. The image holding member according to claim 1, wherein the disconnection layer is on the light guiding layer.
The image holding member described in Section 1. 4. One edge holding member according to item 1 of the patent claim, characterized in that it has a sealing layer between the insulating layer and the optical hole layer.