JPS6093455A - Developer for electrophotography - Google Patents

Abstract

PURPOSE:To improve an electrifying characteristic and resistance to environment and to enable development to a good image by adding fine particles treated with a fluorine substd. silane coupling agent to toner. CONSTITUTION:Fine particles for addition are put into a fluidized bed granulator and a fluorine-substd. silane coupling agent is dissolved in toluene and xylene for example, and is sprayed to fine particles for addition. The sprayed particles are treated by heating. The treated fine particles for addition are added to a toner by using a mixer. The developer is electrified more strongly negatively by the fluorine of the fluorine-substd. silane coupling agent. The appearance of a photographic fog in the image is obviated and the life is extended. The developer is made less dependent on environment. Colloidal silicon dioxide has high electric resistance and is particularly outstanding as the fine particles for addition. The fluorine-substd. silane coupling agent is formed by substituting the hydrogen atom of the alkyl group with fluorine atom and includes, for exampler, n- C6F17CH2CH2Si(OCH3)3, C7F15COOCH2CH2Si(OCH3)3, C9F19SCH2CH2Si(OCH3)3.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a developer for developing an electrostatic latent image in an electrophotographic device.〇Prior Art Conventionally, as a developer for electrophotography, a hydrophobic toner was used as a developer for electrophotography. Many products are used in which polyester fine particles are added or polytetrafluoroethylene is added (for example, Japanese Patent Publication No. 54
-16219, Special Publication No. 54-654, etc.) The reason for this is to improve the fluidity of the toner, prevent toner from aggregating in the hopper or feeder, and improve cleaning performance.

However, when hydrophobic silicon dioxide is added as fine particles to improve the fluidity of the toner, charging is highly dependent on the environment, so the addition needle is preferably in the range of 0.1 to 0.5% by weight. However, this method cannot significantly improve the fluidity of the toner.

On the other hand, when polytetrafluoroethylene is added to the toner, the polytetrafluoroethylene sticks to the carrier, and the toner charge decreases as the number of copies increases, causing capri on the image and shortening the toner's lifespan. This caused the problem that the length became shorter.

・Object of the invention Therefore, the object of the present invention is to solve the above-mentioned drawbacks of the prior art.
We have developed additive particles that can increase the toner's fluidity without sticking to the carrier and increase the amount of toner charge, resulting in excellent charging performance, environmental resistance, long life, and good image development. The purpose of the present invention is to provide an electrophotographic developer that can be used for electrophotography.

Structure of the Invention In order to achieve the above-mentioned object, the electrophotographic developer according to the present invention is one in which fine particles treated with a fluorine-substituted silane coupling agent are added to a toner.

Aspects of the invention Hereinafter, aspects of the present invention will be explained in detail.

First, the fine particles treated with the fluorine-substituted silane coupling agent according to the present invention include silicon dioxide, alumina, titanium dioxide, talc, CaC0, MgC0,
MgSO4, Fe, 0. , 1g30. , ZnO and other metal oxides. Among them, silicon dioxide has a high electrical resistance and is particularly excellent as a fine particle for addition.

Examples of fluorine-substituted silane coupling agents include those in which the hydrogen atom of an alkyl group is replaced with a fluorine atom, and include the following. For example, ru q ~ even ct4sit,
, or4>, .

Lou C29 CH2CM, Si (OCR,).

C2F,, C0IVHC1l, CII, 5i(O
C, #s)s.

C, F,, 50. NB C1i, CJI, CM
tSi(OC,#,), .

C7F,, COOC11IC1l, Si (□ C
B, ), .

et F. There are S CH, CII, Si (OC crow), etc.

The treatment of the fine particles for addition using the 7-substituted silane coupling agent is carried out as follows.

For example, the above-described fine particles for addition are placed in a fluidized bed granulation device, the fluorinated silane coupling agent is dissolved in a desired solvent such as toluene or xylene, and this is sprayed onto the fine particles for addition in the device; The fine particles for addition are placed in a vacuum degassed container, heated and degassed, and the vaporized fluorine-substituted silane coupling agent is added thereto and stirred. can be heated and processed while

The additive fine particles treated with the fluorine-substituted silane coupling agent as described above are added to the toner using a desired mixer to prepare the developer of the present invention.

Effects of the Invention As described above, the developer according to the present invention is a toner in which additive fine particles whose surfaces are treated with a fluorine-substituted silane coupling agent are added to the toner. It has the excellent effects of being more strongly negatively charged, causing no fogging on images, extending its lifespan, and being less dependent on the environment. Further, since a large amount of additive fine particles can be added, a toner with excellent fluidity can be obtained.

Example Hereinafter, the present invention will be specifically explained with reference to Examples.

Example I Alumina (aluminum oxide C1 manufactured by Nippon Aerosil Co., Ltd.) was selected as the additive fine particles, and the 700 I! was placed in a fluidized bed granulator. To this, a fluorine-substituted silane coupling agent (CF, CH2CH1Si(OCH,)3
, manufactured by Shin-Etsu Chemical Co., Ltd.) Diluted with wotoluene to make a 1% solution '1loI! I took it and sprayed it. Then 200
C. to completely adhere the 7-horn substituted silane coupling agent to the alumina surface.

Next, add +g of the fine particles for addition treated as above.
Then, carbon was dispersed in styrene-acrylic resin, pulverized, and added to 100 g of toner which had been classified to a size of about 10 μm, and mixed using a Henschel mixer.

The toner created in this way is mixed with iron oxide powder + ooo
A two-component developer was prepared by adding 30 g to 10 g, and a charge amount measurement, an actual photographic test, and an environmental test were conducted.

Obi 1! The amount was 115 μC/11 for the developer without the additive fine particles, whereas the developer of the present invention was as high as 125 μC/I, confirming that the charging efficiency was good.

Further, the developer according to the present invention may be used in an electrophotographic copying apparatus F.
When a life test was performed using X-2830 (manufactured by Fuji Xerox Co., Ltd.), no fogging occurred in the image even when making 0 or more copies (approximately 40.0 f).

Furthermore, as a result of environmental tests, high temperature and humidity (28℃, gs%
/? Even under the environment B), fogging and the like did not appear and the results were very good.

Example 2 Silicon dioxide (Aerosil 200.
Nippon Aerosil Co., Ltd.) was used, and a fluorine-substituted silane coupling agent (('a F, 7CII, CH, 5i(
OCIJ3)s, manufactured by Shin-Etsu Chemical Co., Ltd.) All treated in the same manner as in Example 1, and 0.5% by weight of the additive fine particles treated in this way was added to the all-polyester toner, and the developer f of the present invention was added. :Obtained.

As a result of evaluating this in the same manner as in Example 1, the chargeability, lifespan,
Both environmental resistance was good.

The developer according to the present invention is also effective as a one-component developer containing only toner.

When the same additive particles as those treated in Example 2 of the present invention were added to the magnetic toner in which r-ferrite was dispersed, frictional charging with the developer-carrying sleeve was improved, resulting in a clear image. was gotten.

In addition, a non-magnetic component development method (% 1988-13088, 54-1113
58 etc.), the frictional electrification with the grade which is the layer regulating member was good, the fluidity of the developer was high, and a uniform and fog-free image was obtained.

Applicant: Fuji Xerox Co., Ltd. Agent: Patent Attorney Masaaki Yonehara Patent Attorney Tadashi Hamamoto

Claims (1)

[Scope of Claims] 1. An electrophotographic developer characterized in that fine particles treated with a fluorine-substituted silane coupling agent are added to a toner. 2. The electrophotographic developer according to claim 1, wherein the fine particles are colloidal silicon dioxide.