JPS6060053B2 - Manufacturing method of photosensitive paint for electrophotography - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing a photosensitive paint for electrophotography comprising a phthalocyanine compound and a binder resin.

Selenium vapor-deposited materials are currently widely used as photosensitive materials for electrophotography, but they have the drawbacks of being complicated to manufacture, extremely toxic, requiring careful handling, and being expensive.

As a countermeasure against this problem, various proposals have been made in recent years regarding the use of non-toxic phthalocyanine compounds in electrophotographic light-sensitive materials. For example, photoreceptors using X-type phthalocyanine obtained by sublimating metal phthalocyanine under reduced pressure, or photoreceptors using modified phthalocyanine compounds obtained by milling phthalocyanine compounds for a long time, are known. . However, it is said that the manufacturing method of these modified phthalocyanine compounds is complicated, has poor reproducibility, and has drawbacks such as large differences in spectral characteristics of visible light such as blue, red, and green regions. .

The purpose of the present invention is to overcome the above-mentioned drawbacks, and to produce a photosensitive paint that is simple, inexpensive, non-toxic, and has excellent photosensitive properties using common phthalocyanine pigments that are widely commercially available as pigments. It is about providing law.

Another object of the present invention is to provide a method for producing a photosensitive coating material having photosensitive characteristics with a small residual potential after attenuation of the surface potential by light irradiation.

Still another object of the present invention is to provide a method for producing a photosensitive coating material in which the surface of the formed photoreceptor film is very smooth and has good copying properties.

Still another object of the present invention is to provide a method for producing a photosensitive coating material that has good dispersion properties for phthalocyanine compounds, such as no secondary agglomeration and little sedimentation. The above purpose is to simultaneously produce a composition solution containing a specific binder resin and a phthalocyanine compound when producing a photosensitive material using a commercially available phthalocyanine pigment without requiring any special production method. This is achieved by kneading, grinding and dispersing operations. That is, the present invention is a method for producing a photosensitive material for electrophotography, which comprises pulverizing and dispersing the phthalocyanine compound in a solution containing polysiloxane, in a method for producing a photosensitive material comprising a phthalocyanine compound and a binder resin. .

The phthalocyanine compound is in powder form, and a photosensitive plate is made by dispersing it in a binder resin solution with film-forming ability to form a coating composition, applying the coating composition onto a substrate, and drying it. The photosensitive characteristics and the surface condition of the photoreceptor film are greatly influenced by the method of manufacturing this coating composition.

The present invention is based on the discovery that an excellent photosensitive coating material can be obtained by kneading, finely pulverizing, and further dispersing a phthalocyanine compound powder in a polysiloxane solution. The polysiloxane used in the present invention includes hydroxy groups, alkoxy groups (0CH3,0C2H5,0
C3H7, 0C4H9, etc.) or vinyl groups are effective.

In addition, in the present invention, although it is possible to use the polysiloxane alone as the binder resin, it is also possible to use the polysiloxane alone as the binder resin, but it can also be used in combination with other binder resins having normal film-forming ability such as polyurethane, epoxy resin, and acrylic resin. More preferably, the polysiloxane content is 10 to 9 parts by volume based on the total amount of binder resin of 10 parts by volume.

When the polysiloxane content is less than 1 part by weight, the effect of improving the photosensitive properties and the surface smoothness of the coating film is small;
When the intensity is 9 or more, the dark attenuation tends to be slightly large. In the present invention, as the phthalocyanine compound,
Commonly commercially available α-type, β-type, or other phthalocyanine pigments can be used, and in particular, when using α-type copper phthalocyanine, which is said to have extremely low photosensitivity, The effect of improving properties is extremely large.

In addition, magnetic balls or copper balls are used for kneading, pulverizing, and dispersing the composition. Possible methods include ball milling, fine milling using sand, etc. Of course, other kneading, grinding and dispersing methods can also be employed. In the present invention, kneading, pulverization, and dispersion are performed in a wet state containing a solvent, and this solvent can be a single solvent capable of dissolving the polysiloxane and binder resin used, or a mixed solvent containing several types of solvents. .

It is not clear why the photosensitive properties are improved by kneading, pulverizing and dispersing a composition containing a phthalocyanine compound and a solution containing a polysiloxane at the same time, but when the phthalocyanine compound is pulverized. Because polysiloxane acts as a lubricant and facilitates pulverization, or because polysiloxane easily adsorbs to the surface of pulverized phthalocyanine compound particles,
Another possible reason may be that the crystal structure of the phthalocyanine compound changes due to the pulverization in the polysiloxane solution.

The present invention will be explained below using examples.

Toyo Ink Manufacturing Co., Ltd. as α-type copper phthalocyanine pigment
NO. Lionol Blue NCB toner manufactured by Toyo Ink Mfg. Co., Ltd. as a 27l2 cyanine blue B1β-type copper phthalocyanine pigment; Dianal BR manufactured by Mitsubishi Rayon Co., Ltd. as a polyol for urethane resins; Takerac U-25s of Takeda Pharmaceutical Co., Ltd. as an acrylic resin -80s-
Shin-Etsu Silicone KR-214 from Shin-Etsu Chemical Co., Ltd. is used as a polysiloxane containing an 0H group, and Toray Silicone S from Toray Industries, Inc. is used as a polysiloxane containing a 0CH3 group.
Using H-61 wings, butyl acetate and toluene as solvents.

After mixing, pulverizing and dispersing these for 100 hours using a ball mill, Takenate D-110N from Takeda Pharmaceutical Co., Ltd. was added as an isocyanate for urethane resin, and as a stirring dispersion, the composition as shown in Table 1 was kneaded. A crushed and dispersed paint was obtained.

Table 2 shows the dispersibility of each of the paints obtained. In addition, each paint was applied on an aluminum plate and dried by heating at 150℃ for 3 hours in the case of composition numbers 1 to ■, and heated at 100℃ for 5 hours in the case of composition numbers ■ and ■. I did drying. The photosensitivity of each of the samples obtained as described above was measured using an improved electrostatic recording paper tester SP-428 manufactured by Kawaguchi Electric. Surface potential ■ when a plus ■■ corona discharge is applied for a second. , the exposure amount required for the surface potential to attenuate to 15 when irradiated using a 10 lux white tungsten lamp after applying a corona discharge.
5. The surface potential (residual potential) 10 seconds after light irradiation, and the smoothness of the coating film were measured, and the results are shown in Table 2. As is clear from Table 2, as the content of polysiloxane increases (composition number 1
→■→■→■→■) Charged potential V.

It can be seen that the photosensitivity is improved, the photosensitivity Ell5 is improved, and the residual potential Vr is also reduced. When polysiloxane is not included (composition number 1),
Sensation of light. The photosensitive characteristics are poor, such as poor Ell5 and high residual potential. Also, when polysiloxane containing -0CH3 groups was used (composition number ■), good photosensitive characteristics were obtained. When acrylic resin alone was used as the binder resin (composition number ■), the photosensitivity was poor, with poor photosensitivity Ell5 and high residual potential (■), but by including polysiloxane (composition number ■), the photosensitivity characteristics were improved. .

Furthermore, when polysiloxane is not included (composition number 11
In case of ■), the phthacyanine pigment in the paint tends to settle and the dispersibility is incomplete, and the surface condition of the paint film is lackluster and poor in smoothness, but in the case of other compositions containing polysiloxane. The dispersibility of the paint was good, and the surface condition of the paint film was glossy and excellent in smoothness.

Next, the photosensitivity Ell5 when irradiated with light using filters of each color was measured for the photosensitive coating film with the composition number ■, and as a result, blue filter No. 47, Ell5 is 2.1 lux, seconds, green filter NO. 58, Ell5 is 3.7 lux, seconds, red filter NO.
At 25, Ell5 was 5.3 lux, seconds, and no large difference was observed between the colors, indicating excellent photosensitivity.

In addition, using paint with composition number ■, color originals containing red, blue, and green are charged by corona discharge of Jukade ■, exposed for 50 lux, seconds, transferred, fixed, and cleaned using a copying machine. As a result, an image with good contrast was obtained. Further, no toner remained on the surface of the photoreceptor, and the surface of the photoreceptor had good smoothness. In addition, the above steps can be repeated in 3 steps.
Even after repeating the process 10,000 times, the surface condition and image of the photoreceptor remained almost unchanged and had good durability. On the other hand, after kneading, pulverizing, and dispersing the compositions of composition numbers (■) and (2) in Example, excluding the polysiloxane and Takenate D-110N using a ball mill for 10 hours, the polysiloxane and Takenate were mixed. Photosensitive coating compositions ``'' and '''' were prepared by adding D-110N and performing ball mill kneading and stirring dispersion for 30 minutes, but the phthalocyanine compound tended to settle slightly and the dispersibility tended to be somewhat poor. It was hot.

In addition, as a result of coating and drying these and measuring the photosensitive characteristics, in the case of composition number "■", VO: 1200 volts, Vl
O; 1100 volts, Ell5: 29 lux, seconds, ■
r: 210 volts, and in the case of composition number ■'',
VO; 1150 volts, VlO: 1000 volts, El
l5: 43 lux, seconds, ■: 290 volts, and both had poor photosensitive characteristics. That is, it is clear that when a composition excluding polysiloxane is kneaded, pulverized and dispersed, and then polysiloxane is added and mixed, the dispersibility of the coating material and the photosensitive properties of the coating film are poor. As described above, when producing photosensitive paints using commonly available phthalocyanine compound pigments, a composition containing polysiloxane and its solvent is kneaded, ground, and dispersed using a ball mill or the like. By manufacturing the paint, it has excellent photosensitive properties such as a large charged potential, a fast decay rate of the surface potential due to light irradiation, and a small residual potential after light irradiation, and has good dispersibility, and the coating film is It has excellent smoothness, and the manufacturing method is simple and inexpensive.
This has the effect of making industrial manufacturing extremely advantageous.

Claims (1)

[Scope of Claims] 1. A method for producing a photosensitive paint for electrophotography, which comprises pulverizing and dispersing a phthalocyanine compound in a solution containing polysiloxane. 2. The method for producing a photosensitive paint for electrophotography according to claim 1, wherein the solution contains a binder resin. 3. The method for producing a photosensitive paint for electrophotography according to claim 1 or 2, wherein the phthalocyanine compound is α-type copper phthalocyanine. 4. The method for producing a photosensitive paint for electrophotography according to claim 1 or 2, wherein the polysiloxane is a polysiloxane containing a hydroxy group, an alkoxy group, or a vinyl group.