JPS5940651A - Two component type developing toner and method of using it - Google Patents

Abstract

PURPOSE:To obtain a permanent image having superior developability and transferability, and high resolution, and causing no fog, by transferring a toner image obtained by developing an image by using a developer composed of a specified toner and a magnetic carrier to a transfer material. CONSTITUTION:A 2-component type developing toner having 6-13mum average partice diameter, <=5mum particles weighing <=15wt%, >=16mum particles weighing >=2wt% and 27-40% compression degree is obtained by incorporating 0.005- 50wt% cross-linking agent, such as divinylbenzene, 1-20wt% colorant, such as carbon black, and when needed, an offset inhibitor, a dispersion stabilizer, etc. in a binder resin, such as polyester resin. A toner image is formed by developing an electrostatic image with a magnetic brush by using a developer consisting of this toner and a magnetic carrier, and transferred to a transfer material and then, fixed with a heat roll.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a toner for a two-component developer and a method of using the same.

In forming a visible image by electrostatic recording or electrophotography, the particle size, particle size distribution, fluidity, etc. of a toner for developing an electrostatic image have a significant influence on development, transferability, and ultimately image quality.

Regarding the fluidity of toner, Japanese Patent Application Laid-Open No. 56-164367
JP-A No. 57-24950 and JP-A-57-24950 describe the use of toner having a degree of compression within a predetermined range. For example, a technique has been disclosed in which a magnetic (-component) toner having a particle size of 5 to 25 μm and a degree of compression of 25 to 38 inches is used, and a single layer of finely compressed thin toner is brought into contact with an electrostatic image to develop it. However, since this technique uses a -component developer, it is a technique that can be achieved in combination with a special developing method. That is, it is necessary to precisely compress one layer of magnetic toner using a wide regulating member to form a thin layer, and to develop this thin layer by conveying it by magnetic force. By adopting such a development method, development is achieved using a magnetic toner having a wide range of fluidity with a compression degree of 25 to 38 inches.

However, these developing methods are special.

Usually, -C soft spikes are formed by magnetic force, and the toner in the spikes is brought into contact with an electrostatic charge image to be developed.

By the way, there is a recent demand for improving the resolution of toner images obtained by development, and for this purpose, the average particle size is 6 to 6.
It is desired to use a toner with fine particles of 13 μm. However, as the toner particles become finer, the fluidity of the toner as a developer decreases, resulting in poor developability, and furthermore, there are disadvantages in that the transfer rate to transfer paper and cleaning performance are also decreased. On the other hand, when fixing a toner image to make a permanent image, hot roll fixing is said to be preferable from the viewpoint of fixing efficiency and fixing speed, but since hot roll fixing is contact fixing, the hot roll is contaminated with toner. , there is a problem that a so-called offset phenomenon occurs.

In order to prevent this, it is said to be a good idea to include an anti-offset agent such as a low softening point polyolefin, metal soap, higher alcohol, or higher fatty acid amide in the toner, but such anti-offset agents reduce the fluidity of the toner. It gives rise to the disadvantageous problem of being forced to do something.

On the other hand, in the case of a development method using a two-component developer, when the average particle size of the toner is made finer, ultrafine toner particles are contained vertically, causing capri in the toner image and deteriorating the image quality. There is a positive trend.

The present inventor has completed the present invention as a result of studying the characteristics of a two-component developer using fine toner, particularly when applied to a magnetic brush development method.

An object of the present invention is to provide a toner for a two-component developer that has excellent developability and transferability and is capable of forming a capri-free, high-resolution toner image and a permanent image thereof. Another object of the present invention is to provide a method for using a toner for a two-component developer (i.e., an image forming method) for forming high-quality images using a magnetic brush development method and preferably a hot roll fixing method. There is a particular thing.

These objects, according to the invention, contain a binder resin and a colorant and have an average particle size of 6 to 13 μm (preferably 8 μm).
~10 μyn), the particles of 5 μm or less are 15% by weight or less, the particles of 16 μm or more are not more than double weight,
and compression degree is 27-40% (preferably 27-38%)
This is achieved by a toner for a two-component developer characterized by the following.

Using a developer comprising the toner according to the present invention and a magnetic carrier, an electrostatic charge image is developed with a magnetic brush to form a toner image, this toner image is transferred to a transfer material, and more preferably, it is fixed by a hot roll. You can obtain high-quality permanent images.

According to the present invention, the average particle size of the toner is 6 to 13 μm as described above.
The resolution and sharpness of the image improves due to the fineness of the toner, and at the same time, the reduction in fluidity caused by the fineness is reduced by setting the degree of compression of the toner between 27 and 40 inches. Therefore, toner transportability on the developing brush, development performance, transfer rate, image density, and cleaning performance are all improved. That is, if the average particle size of the toner is less than 6 μm, it is too fine and the fluidity is extremely reduced, but if it exceeds 13 μm, the particles are too large and the resolution and sharpness are significantly deteriorated, and furthermore, the degree of compression is less than 27 inches. If it exceeds 40 inches, the fluidity will be excessive and problems such as toner scattering will occur, and if it exceeds 40 inches, the fluidity will be significantly reduced. Therefore, the average particle size and degree of compression of the toner should be limited to the above-mentioned ranges.

In addition, according to the present invention, the particle size of the toner is not only set to the above-mentioned average particle size, but also particles with a particle size of 5 μm or less and particles with a particle size of 16 μm or more are set to have a content within a specific range as described above. It is important that it is limited. That is, 5
The fluidity of the toner as a whole can be maintained appropriately by reducing the amount of particles of 16μm or less to 155% by weight or less, and
By controlling the amount of particles of n or more to 2% by weight or less, the entire toner can be made into fine particles, and a toner with sufficiently uniform particle size can be obtained.

In particular, the toner of the present invention is fundamentally different from the case of a one-component system as described above, and the toner of the present invention is used in a two-component system, and the carrier used together with the toner itself generally consists only of a magnetic material and is fluid. The fluidity of the toner in conjunction with the carrier, which is rich in fluidity and has excellent transportability, affects the image quality, and when the fluidity is poor, 77
(Van der Walls) Increased force lowers developability and transfer rate, and too high fluidity tends to cause toner scattering. Moreover, in either case, the triboelectricity of the toner due to the carrier becomes non-uniform, and the problem of deterioration of image quality in this respect cannot be ignored. Therefore, in a two-component developer combined with a carrier, the problem of toner fluidity is extremely important, and for this reason, the above particle size range and compression degree range of the toner according to the present invention are essential conditions. .

The toner according to the present invention may be in the form of fragments prepared by a known kneading method, or spherical particles obtained by a known spray drying method (hot air treatment) or suspension polymerization method. good. Further, the particle size can be measured using a Coulter Counter (manufactured by Nikkaki Co., Ltd.).

The degree of compression of the toner can be measured using a known powder tester (model PT-D manufactured by Fine Powder Engineering Research Institute), where -A is the degree of compression c --, -x 1oo (where P is the compaction density after tapping, A can be determined from the relational expression (silent bulk density before cod pink). That is, for example, a diameter of 50
Toner powder is loosely filled into a container having a volume of 10IR1 from above through a 24-mesh sieve, and the weight is measured to determine the bulk density A. Next, fit a frame with the same diameter into the container, add toner powder, and apply it to a tapping device to a falling height of 18V.
Tag 150 times with iffi.

Then, remove the frame, cut the powder at the upper edge of the container, weigh it, determine the density P, and solidify it to obtain the bulk density.

Inserting A and P thus obtained into the above equation, the degree of compression C is obtained.

As the binder resin constituting the toner according to the present invention, the following can be used.

Styrene-acrylic resin: Heavy average molecular weight/number average molecular weight = 3.5 to 4o, number average molecular weight is 2,000 to 30,000. Divinylbenzene, etc. can be used as a crosslinking agent.

A condensation polymer of polyester resin diol and dicarboxylic acid,
Polyhydric carboxylic acids and acid anhydrides with higher valences are used to increase the anti-offset effect as a three-dimensional structure (for example, polyester resins disclosed in JP-A-57-37353).

Styrene-butadiene resin: 1 (contains a molecular weight component of 10,000 or more in a weighted amount or less, and a molecular weight component of 500,000 or more in a weighted amount of 15 weights or less (for example,
Patent Application No. 56-35168, 5G-35169, 56
-35170-5″F156-35171, 56-
35172 and 56-35173).

In addition to the above, conventional binder resins for electrophotographic toners can be used as appropriate, such as known epoxy resins and butyral resins.

In addition to divinylbenzene, crosslinking agents for the binder resin include divinylnaphthalene, diethylene glycol acrylate, diethylene glycol methacrylate, trimethylolpropane acrylate, acrylic methacrylate, and t.
-Butylaminoethyl methacrylate, tetraethylene glycol dimethacrylate, 1,3-butanediol methacrylate, ethylene glycol dimethacrylate, tetramethylolmethanetetraacrylate, N-divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, etc. can be used. be. The crosslinking agent may be added in an amount of 0.005 to 20% by weight (preferably 0.1 to 5% by weight) based on the polymerizable monomer of the binder resin.

In addition, usable colorants include carbon black,
Examples include nigrosine, aniline blue, calco oil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, rose bengal, etc., and the amount added depends on the binder resin. It may be 1 to 20 times.

Additionally, other substances may be added to the toner to improve its properties. As an anti-offset agent that can be added, low-molecular polyolefins such as polypropylene and polyethylene (either homopolymers or copolymers may be used.The softening point is J
May be 80-180°C, 100-160°C when measured by the ring and ball method according to IS Standard 2531-1960
is preferred. ), known fatty acid metal salts such as zinc salts of maleic acid, JIW fat M esters such as ethyl maleate, partially saponified fatty acid esters such as partially saponified calcium of moapate esters, and higher fatty acids such as dodecanoic acid. , higher alcohols such as lauryl alcohol, liquid solid paraffin wax, amide waxes such as stearic acid amide, polyhydric alcohol esters such as glycerin stearate, silicone waxes such as methyl silicone waxes,
Examples include ethyl tetrafluoride, ty) aliphatic fluorocarbons, and the like. The ratio of this offset inhibitor to the binder resin is preferably 0.5 to 20% by weight, and 1 to 10% by weight.
Weight percent is preferred.

In order to further improve the fluidity of the toner of the present invention, particles of silica, alumina, vinylidene fluoride, fluorinated fine powder, etc. are placed in the toner in an amount of 0.01 to 2.0 times (preferably 0.01 to 2.0 times).
．． 05-1.5% by weight) or 11? j
6 polymerization method or granulation polymerization method (water-soluble polymers such as gelatin,
Fine powder of a water-repellent inorganic compound such as barium sulfate is used as a dispersion stabilizer), and the pulverized toner is spray-dried (hot air treatment) to make the toner spherical.

As a magnetic carrier that can be used in the stroke number forming method according to the present invention, a conventional iron powder carrier, a so-called coachite carrier whose surface is coated with a resin, or a so-called coachite carrier can be used.

Next, the present invention will be described in detail, but the following embodiment 1] can be variously modified based on the technical idea of the present invention.

Example 1 As the binder resin, styrene-methylene methacrylate-1.-〇-butyl methacrylate (50: 2+)
:30) was synthesized, and a mixture (40:100) of this high molecular component and low molecular component was prepared. This mixture was mixed with a binder resin (Mv-130,000, K-8000, Mw/M♂-16,25) [7] The following composition was prepared.

Binder resin 100 parts by weight CB (Mogul L: manufactured by Cabot) 10 parts by weight Viscoel 660P (mold release agent) 3 parts by weight The composition was melted and kneaded, then pulverized and classified to obtain an average particle size of 11.2 μm. Get toner. This toner contains 0.5% by weight of particles of 5μ7n or less and 1% by weight of particles of 16μm or more,
Also, the degree of compression of the toner is 2 according to the prescribed measuring method mentioned above.
It was 9.8%. Further, 0.8% by weight of hydrophobic silica R-972 (manufactured by Nippon Aerosil Co., Ltd.) was added to this toner.

Example 2 In Example 1, a crosslinked product of styrene-〇-butyl acrylate (M w = 150,000, M
A toner was prepared using n = 20,000, a crosslinking agent (ethylene glycol methacrylate), and other similar conditions.

The average particle size of the obtained toner was 9.1 μm, the amount of particles smaller than s μm was 0.7% by weight, and the amount of particles larger than 16 μm was 0.
．． 2% by weight, and the degree of compression was 33.5 inches.

Example 3 The following compositions were thoroughly mixed with a sand stirrer.

Styrene 70 parts by weight - Butyl methacrylate 30 parts by weight Mitsubishi Carbon Black MA-600 (manufactured by Mitsubishi Kasei ■)
5 parts by weight Viscoel 660P 3 parts by weight Leopard KE (Dispersion stabilizer: Kai-tsu Kagaku ■l!
j) 1.5 parts by weight2.
2'-Asohysu(2,4-dimethylvaleronitrile)
3 parts by weight trimethylolpropane triacrylate 0.8 parts by weight, then 3% by weight aqueous calcium phosphate solution and NL-R
(16,4 water solution) 0.24. ! The above mixed composition was added to ii' using a TK homogenizer (manufactured by Tokushu Kogyo ■) under stirring at 5000 rpm. In this addition, the oil droplets of the particles were very stable, and as a result of observation with an optical microscope, the dispersibility of carbon into the oil droplets was very good. Thereafter, the mixture was stirred at a speed of 1,100 rpm using an ordinary stirrer, and a polymerization reaction was carried out at 60° C. for 6 hours. After the polymerization reaction was completed, the product was cooled, treated with concentrated hydrochloric acid, dehydrated, washed, and dried.
Particles with an average particle size of 9μ711.5μm or less are 0.7 times IJ
A toner with iJL%, particles of 16μ711 or more ()2μ≠, and a compression degree of 33.3% was obtained.

Example 4 [Example 1] The type and amount of CB added were the same as in Example 1, the polyester resin disclosed in JP-A-57-37353 was used as the binder resin, and a toner was prepared according to the following formulation.

Polyester resin 100 parts CB (1-
IC) 10 parts Viscole 660P
Kistwasox to the 2nd part 0
A toner was prepared using 2 parts, and when 8 parts of hydrophobic silica R-9720 was added as an external additive to this toner, the degree of compaction was 34.8%.

The obtained toner had an average particle size of 8.5 μm, the amount of particles of 5 μm or less was 0.5% by weight, and the amount of particles of 16 μm or more was 0.5% by weight.
2% by weight, and the degree of compression was 348%.

Example 5 In Example 4, 0.8% by weight of hydrophobic silica R-972 and 0.2% by weight of zinc stearate were added externally. The degree of compression of the obtained toner was 36.8%.

Example 6 In Example 4, the average particle size of the toner was 8.5 μm, the particles of 5 μm or less were 10% by weight, the particles of 163 m or more were 0.2% by weight, and hydrophobic silica R-972 was 0.5% by weight. 8
% by weight was added. The compression degree of the obtained toner was 35.7 inches.

Example 7 The toner containing the binder resin used in Example 1 was spheroidized by a spray drying method. The average particle size of this spherical toner is 9.2 μm, and particles of 511 m or less are 0.5% by weight, 16
The amount of particles larger than μm was 0.3% by weight, and the degree of compaction was 33.2%.゛Comparative Examples 1 to 3 Comparative Example 1 toners in which no external additive (hydrophobic silica n-972) was added in each of the toners of Examples 2.4.6.
, Comparative Example 2, and Comparative Example 3. These showed the following degree of compression.

Toner of Comparative Example 1 Compression degree 41% Toner of Comparative Example 2 Compression degree 41.5 Toner of Comparative Example 3
Using each of the toners of Examples 1 to 7 and Comparative Examples 1 to 3 with a compression degree of 42.3 inches or more, a developer consisting of 2 parts by weight of toner and 98 parts of cochoid carrier (resin-coated carrier) was prepared. Created. Using each of these developers, an electrophotographic copying machine (U-I3ix3 manufactured by Konishiroku Photo Industry ■)
000), development was performed using a magnetic brush method, the toner image was transferred to a transfer material, and fixing was performed using a hot roll.

When the obtained images were evaluated, the results shown in the table below were obtained. Incidentally, the toner charging law was adjusted to 22:HlμC/9 for all toners by the usual blow-off method.

In the above table, "-fire adhesion amount" indicates the toner adhesion amount in solid black, and "storability" is under the conditions of 60°C and 55 SRH, where ○ is good, △ is slightly poor, × indicates defective.

From the above results, it can be seen that by using the toner according to the present invention, it is possible to obtain copies that are very excellent in terms of developability, transfer rate, image quality, etc. Regarding the toner of the present invention,
A printing durability test of 20,000 copies was conducted using U-Bix 3000, and the image remained unchanged from the initial state, there was little toner scattering, and the amount of charge was stable.

Agent: Hiroshi Aisaka, Patent Attorney (Volunteer): 'J Senji Ne Ichi Masaino: November 3, 1980 Former Commissioner of the Japan Patent Office Kazuo Wakasugi 1, Indication of Case 1980 Patent Application No. 150595 2 , Title of the invention: Toner for two-component developer and its method of use 3, Relationship with the case of the person making the amendment Patent applicant address: 1-1126-2 Nishi-Shinjuku, Shinjuku-ku, Tokyo Name (127) Roku Konishi Photography Kogyo Co., Ltd. 4, Agent 6, Number of inventions increased by amendment 7, Detailed explanation column (1) of the invention in the specification series subject to amendment, [Diethylene glycol acrylate] in lines 4 to 1 from the bottom of specification 9・・・・・・・・・Acrylic methacrylate-1・" will be corrected to "diethylene glycol diacrylate, diethylene glycol acrylate 1~, Torino Senropra L1 pantriacrylate-1~, allyl methacrylate."

(2), page 10, lines 2-3, "1,3-butanediol methacrylate" has been corrected to "1,3-butanediol methacrylate."

(3), page 1O, lines 4-5, corrected to read ``N-divinylaniline 7J as rN,N-divinylaniline''.

(4) In the last line of page 10 to the first line of page 11, "for low molecules" is corrected to "low softening point."

(5) On page 13, lines 6-5 from the bottom, "1 ethylene glycol methacrylate" has been corrected to "ethylene glycol dimethacrylate."

(6) First, correct r HCJ in line 7 from the bottom of No. 15 to read "Mogull 1.: Manufactured by Cabo Soto."

- Above - January

Claims (1)

[Claims] 1. Contains a binder resin and a colorant, and has an average particle size of 6
For a two-component developer, characterized in that the particle size is 13 μm or less, the particle size of 5 μm or less is 15% by weight or less, the particle size of 16 μm or more is 2% by weight or less, and the degree of compression is 27 to 40 inches. toner. 2. Contains binder resin and colorant, average particle size is 6.
~13 μm, particles of 5 μm or less are 15% by weight or less, particles of 16 μm or more are 2 i% or less, and the degree of compression is 27 to 40 inches, and a developer consisting of a magnetic carrier. 1. A method of using a toner for a two-component developer, characterized in that a toner image is formed by developing an electrostatic charge image with a magnetic pusher, and the toner image is transferred to a transfer material.