JPS60135956A - Developer - Google Patents

Abstract

PURPOSE:To obtain a toner good in pressure fixability by using a fine powder of hollow carbon fibers in addition to the toner. CONSTITUTION:Hollow carbon fibers are incorporated in the toner of a conventional developer or mixed with the toner to obtain a developer. The hollow carbon fibers are obtained by using ultrafine particles of Fe, Ni, Co, or the like produced, e.g., by the gas evaporation method, having 10-30nm diameter as a catalyst, decomposing CO or hydrocarbon gases, such as CH4, heated to 400- 600 deg.C, and growing the obtained carbon in the gas phase. The developer is obtained by mixing the hollow carbon fiber with the toner, preferably, in an amt. of 0.01-3, especially, 0.3-2pts.wt. per 100pts.wt. of the toner.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a developer (I-ner) used to develop an electrical latent image or a magnetic latent image in electrophotography or electrostatic printing. be.

Conventionally, electrophotography methods include US Patent No. 2297691, Japanese Patent Publication No. 42-23910, and Equity No.
A number of methods are known, such as those described in Japanese Patent No. 143-24748, etc.; Then, the latent image is developed using toner, and if necessary, the l/toner image is transferred to a transfer material such as paper, and then fixed by heat, pressure, solvent vapor, etc. to obtain a copy. Various methods are also known for visualizing electrical latent images using toner. For example, US Patent No. 2874063
Magnetic brush method described in No. 26185
The cascade development method described in the specification of No. 52, the powder cloud method and fur brush development method described in the specification of No. 2221776, and the liquid development method. As toners used in such applications, fine powders in which dyes and pigments are dispersed in natural or synthetic resins have conventionally been used. Furthermore, it is also known to use fine developing powder to which a third substance is added for various purposes.

The developed toner image is transferred and fixed onto a transfer material such as paper, if necessary.

Methods for fixing toner images include a method in which the toner is heated and melted using a heater or a heated roller, etc., and fused to the support, and a method in which the binder resin of the toner is softened or dissolved with an organic solvent and fixed to the support. , a method of fixing toner on a support by applying pressure, etc. are known.

Here, the quality of the toner is selected to suit each fixing method, and generally, the toner used for a particular fixing method cannot be used for other fixing methods.

4.-, heat f using a conventionally widely used heater
It is almost impossible to transfer the toner used for self-fixing to heat roller fixing, solvent single fixing, pressure fixing, etc. Therefore, toners suitable for each fixing method are being researched and developed.

A method of fixing toner by applying pressure is disclosed in U.S. Pat. No. 326
9626 Specification, Special Publication No. 46-15876 - Official Gazette, it is energy-saving, non-polluting, allows copying without waiting time when the machine is turned on, and prevents burnt copies. There are many advantages such as there is no danger, high-speed fixing is possible at +Nf, and the fixing device is inside the cylinder.

However, there are problems such as the fixing properties of I-ner and offset development on the pressure roller, and various research and developments are being carried out to improve the pressure fixing properties. For example, Tokuko Sho 44-988
Publication No. 0 describes a pressure fixing toner containing an aliphatic component and a thermal ITf plastic resin, and is disclosed in Japanese Patent Application Laid-open No. 75032/1983.
No. 48-78931, I'W 49-17739
No. 52-108134 describes a capsule-type pressure fixing toner containing a soft material in the core, and JP-A-48-75033 describes a capsule-type pressure fixing toner containing a soft material in the core. Pressure fixing toners using block copolymers have been described.

However, it is easy to manufacture, has sufficient pressure fixing performance, does not cause offset development to the pressure roller, and has stable development performance and fixing performance even after repeated use. No pressure fixing toner has been obtained that satisfies practical properties such as not adhering to the sleeve or photoreceptor surface, and having good storage stability without clumping or caking during storage.

Furthermore, as in the methods described in Japanese Patent Application Laid-open No. 54-42141 and Japanese Patent Application Laid-Open No. 55-18656 proposed by the present applicant,
There is a method in which an electrostatic latent image is developed using a one-component developer that contains magnetic fine particles in toner particles and does not use carrier particles. Dispersibility, adhesion, toner impact resistance, fluidity, etc. are maintained. Additionally, during development due to frictional charging between this -component developer and the developing sleeve roller, insulating substances may separate due to LI79 or use over time, and may accumulate on the sleeve roller due to the frictional charging action. -Component developers also have many problems, such as extremely poor durability. In addition, recently, unfiled applicants have filed patent applications in
As proposed in No. 8-71687, for example, electrostatic image development in which a developer t1 carrier holding a developer on the surface is opposed to a latent image carrier and an electrostatic image on the surface of the carrier is developed. In the method, the developer 11 stored in the developer storage means is pumped up onto the developer carrier, and the developer in the pumped-up portion is activated by applying vibrations, and the developer is developed. A developing method has been proposed in which a developer layer of a predetermined thickness is formed on the surface of a developer carrier and subjected to development.

The present invention is suitable for the various developing methods mentioned above, eliminates the drawbacks of conventional toners as described above, and further improves fixing performance, environmental stability, and stability of friction and EF electricity. The object is to provide effective magnetic and non-magnetic developers.

According to the research conducted by the present inventors, it has been found that containing hollow carbon fibers in the developer is effective in achieving the above-mentioned object.

The developer of the present invention is based on such knowledge, and more specifically, in a developer containing a toner made of fine particles of binder in which a colorant is dispersed, the developer further includes a toner in the toner or in combination with the toner. It is characterized by containing hollow carbon fibers in the #rii composite form. less than,
Regarding the significance of hollow carbon fibers in the developer of the present invention,
Let me explain in some detail.

For example, in order to improve the pressure fixability, magnetic toners usually contain magnetic powder in the binder, and the content of this magnetic powder greatly affects the pressure fixability. That is, if the content of magnetic powder is large, frictional charging will not occur effectively, making it impossible to develop using the so-called jumping development method as described in JP-A No. 55-18656, and the fixing properties will be extremely poor. Therefore, it is essential to suppress the magnetic powder-containing knee to the minimum required value. However, if IX is used, the image will have uneven density. This is because the thickness of the toner coating formed on the developing sleeve will be disturbed. In other words, if the magnetic powder content is extremely small, This is because toner having an extremely large amount of frictional charge is attracted to the sleeve, and the magnetic field no longer carries the sleeve 1-.Therefore, there is an optimum ψ for the content of magnetic powder in the paint.

In the present invention, by using hollow carbon N and miscellaneous fine powder in combination, the magnetic powder content can at least prevent the occurrence of image density unevenness, and as a result, it is possible to provide a toner with good pressure fixability. This is what I discovered.

At the same time, there is also an aspect of environmental stability. Toner generated by friction with the sleeve as described above usually has a high amount of triboelectric charge in a low humidity atmosphere and a low amount in a high humidity atmosphere. Therefore, in a low humidity atmosphere, the image density (herein generally used in the sense of maximum image density) is high, resulting in uneven density of the image, and conversely, in a high humidity atmosphere, the image density decreases.

The developer of the present invention has the nf ability to eliminate such drawbacks. That is, in the present invention, the fine powder of hollow carbon fibers to be mixed acts as a triboelectric charge control agent, and the developer of the present invention can be used in various atmospheric environments as a result of such mixing of hollow carbon fibers. 111: It is assumed that the triboelectric charging is stabilized.

Therefore, the effects of hollow carbon fiber-based fine powder include the following.

1. Improved environmental stability and reduced concentration unevenness due to low humidity
It also has the advantage that it does not cause any problems, and there is no decrease in image clarity even at high humidity.

2. In the case of a magnetic stabilizer, the content of magnetic powder can be reduced, which improves pressure fixing properties.

3. The hollow carbon fibers in the developer are expected to stick to the transfer paper and create an anchoring effect, resulting in improved pressure fixing properties.

4. Because the carbon fiber is hollow, the developer weight is apparent.
- It is advantageous for a developer that fixes at low pressure because it is lightweight and the load on the developing machine is small.

5. Hollow carbon fibers have good thermal conductivity, so less heat energy is required for heat fixing.

Hereinafter, the structure of the developer of the present invention will be explained in more detail. In the following description, "%" and [
Sections are based on weight 1.1 unless otherwise specified.

The composition of the developer of the present invention is basically the same as that of a conventional developer except that it contains hollow carbon fibers.

That is, examples of I.na's 71 resins include homopolymers of styrene and its substituted products, such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene, styrene-p-chlorostyrene copolymers, and styrene-hinyltoluene copolymers; Copolymers thereof; copolymers of styrene and acrylic esters such as styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-n-butyl acrylate copolymer; styrene-methacrylate Copolymers of styrene and methacrylic esters, such as acid methyl copolymers, styrene-ethyl methacrylate copolymers, and styrene-n-butyl methacrylate copolymers; Copolymers: Other styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-butadiene copolymer, styrene-vinyl methyl ketone copolymer, styrene-acrylonitrile-intene copolymer, styrene-maleic acid Styrenic copolymers of styrene and other vinyl monomers such as ester copolymers; polymethyl methacrylate-1, polybutyl methacrylate, polyvinyl acetate.

Polyester, polyamide, epoxy resin, polyvinyl butyral, polyacrylic acid, phenol resin, aliphatic or alicyclic hydrocarbon resin, petroleum resin, 174-compound paraffin, etc. can be used in combination.

Especially suitable for pressure foot li method!・As a binder resin for the glue, low-molecular polyethylene, low-molecular polypropylene, ethyl/vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, higher fatty acid, polyamide resin, polyester resin, etc. may be used alone or ljl! Can be used together.

The polymer used, J (polymer or polymer blene I
More desirable results can be obtained by containing a vinyl aromatic or acrylic monomer represented by styrene in an amount of 40% or more.

When the toner is used as a color toner, a coloring agent may be added as necessary, and well-known pigments and dyes can be used as the coloring agent.

Examples of dyes include C,1, tie left dye 1,
C,1, Tirek Iren l' 4, C,1, Asin Trend 1, C,1, Basin Trend 1. C, 1, Mortan trend 30, C,, 1, tie μ'l' lbu/
l/ -1, 0, L tie l/Lido Blue 2, C, 1, Asindo Blue 9, C, 1, Asindo Blue 15, c, r
, Basic Blue-3, C.

To-Sync Blue 5, C, 1, Mordand Blue, C
,1, Direct Green 6, C,1, Basic Green 4. There are C, 1, Basic Green 6, etc.

Pigments include yellow lead, cadmium yellow, mineral fast yellow, navel yellow, naphthol yellow S, Hansa yellow G, permanent yellow NCG.
, Tartrazine Lake, Red [1 Yellow Lead, Molybdenum Orange, Permanent Orange GTR, Pyrazolone Orange, Benzidine Orange G, Cadmium Red, Permanentrene F' 4 R, Watching Glend Calcium Salt, Eosin Lake, Brilliant Carmine 3B, Manganese Purple , Fass I/Violet B, Methyl Violet Lake, Dark Blue, Cobalt Blue, Alkaline Blue Lake, Victoria Blue Lake, Phthalocyanine Blue,
First Sky Blue, Indance Tremble-BC,
Chrome green, chromium oxide, pigment green B,
There are Malachite Green Lake, Final Yellow Green G, etc.

Further, in order to make the magnetic material 1.sup.-, magnetic powder is contained. Examples of such magnetic powders include ferromagnetic f'l elements such as iron, cobalt, nickel, and mankan, as well as magnetite and hematite containing these elements.・There are alloys and compounds such as ferrite.

The magnetic powder content is preferably 15 to 80% by weight based on the weight of the toner layer.

The magnetic material preferably has an i+i average particle diameter of 20mp to 0.
．． 5 rivers, specific surface area 5, 0-100 m2/g
The one is good.

The developer of the present invention can be used in a toner as described above or
- It is obtained by including hollow carbon H&male in a mixed form with the above toner.

The hollow carbon fiber is made of, for example, Fe manufactured by a gas evaporation method,
Co or CH4 heated to 400 to 600°C using 100 to 300 ultrafine particles of Ni, Co, etc. as a catalyst.
It can be obtained by vapor phase growth of carbon produced by (1) by decomposing carbon-hydrogen scum such as carbon. The carbon fibers obtained by this method have the same crystal structure as graphite, and as they grow, the catalyst moves and they become hollow.

When forming a developer by mixing hollow carbon fibers with toner, the amount of hollow carbon fibers is 0 to 100 parts of toner.
．． 0.01 to 3 parts is suitable, and 0.03 to 2 parts is particularly good. That is, if it is less than 0.01 part, "density unevenness" occurs in the image, and if it exceeds 3 parts, not only the pressure fixing properties are inhibited, but also the image density is lowered at high humidity.

When it is contained in the toner, it is preferably 0.1 to 10 parts per 100 parts of the binder in the toner.

In the developer of the present invention, a charge control agent and a fluidity modifier may be further added as necessary, and these charge control agents,
The fluidity modifier may be included in the toner particles in the same way as the hollow carbon fibers, or may be used by being mixed with the toner (externally added).

Examples of the charge control agent include metal-containing dyes such as 1 and nigrosine, and examples of the colorant include conventionally known dyes,
Pigments can be used, and fluidity modifiers include colloidal fluids, fatty acid metal salts, and the like. Further, for the purpose of increasing the amount, fillers such as charcoal-resistant Calcium 11 and finely powdered silica can be incorporated into the toner in an amount of 0.5 to 20 wt%. Furthermore, in order to prevent mutual agglomeration of toner particles and improve its JAL mobility, a fluidity improving agent such as fine Teflon powder may be added, which improves the releasability during hot roll fixing. 1.1 Add about 0.5 to 5 wt% of waxy substances such as low molecular weight fil polyethylene, paper content /, -:, You can also do that.

The present invention will now be explained in more detail with reference to Examples.

The mixture was kneaded for 10 minutes using a mill, cooled, and pulverized using a jet mill, and then classified into 5 to 25 g to obtain a toner. Next, to 100 parts of this, hydrophobic colloidal silicone ([] manufactured by Hon Aerosil Co., Ltd., trade name R972)
0.6 parts, hollow carbon fiber (outer diameter O15 m, length Ig
(pulverized to less than m) l and O part for 30 seconds using a coffee mill (small grinder made by Shibata Rika),
A developer was obtained. Next, an electronic copying machine (cannon acid N, P-1
20) and conducted an environmental test. 15°C110%
In an atmosphere of 35° C. and 85% RH, no decrease in image density was observed, and no “density unevenness” occurred in the 1IIII image.

As a comparative example, a similar environmental test was conducted using a magnetic developer obtained in the same manner as in Section 2 except that no hollow carbon fibers were externally added.
The concentration was uneven.

1. The compound 11 described above was kneaded for 10 minutes using a roll mill heated to 160°C, cooled, and then crushed using a gent mill and then classified into 5 to 25 g.
Also. Next, to 100 parts of this 1.S.
72) 0.3 parts, same as Example 1, iR'J
10.5 parts of the #1 fiber was mixed with Noer 6 for 30 seconds using a coffee mill to obtain a developer.

Using this developer, an electronic copying machine (cannon acid, NP2
(O0J) and an environmental test was conducted.

In the atmospheres of 15°C, 10% and 35°C, 185% RH, no low image density was observed, and there was no uneven density in the images.

As a comparative example, a similar environmental test was conducted using a magnetic developer obtained in the same manner as described above except that no hollow carbon fibers were externally added. It was born.

History 11) The mixture was kneaded for 10 minutes using a mill, cooled, and then ground using a jet mill, and then classified at 5 to 25 minutes to give 1.5 to 4').

Next, to 10 parts of this toner, 0.06 parts of hydrophobic colloidal silica (trade name R972, manufactured by Nippon Aerosil Co., Ltd.) and 80 parts of magnetic particles with an average particle size of 40% were added using a coffee mill (Shiba [■
A developer was obtained by mixing for io seconds using a compact pulverizer (manufactured by Rika).

Next, using this developer, an electronic copying machine (cannon acid NP
-10) was modified so that only toner was applied to the developing sleeve in the developing kit, and copying operations were performed in various environments.

No decrease in image density was observed in an atmosphere of 15°085% RH.

As a comparative example, a modified electronic copying machine was prepared in the same manner as in Example 3 using the developer obtained in the same manner as in Example 3, Example 1, and Example 2 except that it did not contain hollow carbon fibers. An environmental test was conducted using the same conditions as in the example under various development conditions.
In an atmosphere of 5% RH, a decrease in image density and uneven image density occurred.

Claims (1)

[Claims] A developer containing a toner made of fine particles of Bainggu containing a colorant, further comprising hollow carbon fibers in the toner or in a mixed form with the I-toner. .