JPS6159455A - Toner - Google Patents

Abstract

PURPOSE:To improve the fixability of a toner at low energy by incorporating a compd. having a hydrocarbon chain and having 1-30cps melt viscosity at 100 deg.C an coloring agent having <=5mum particle size into said toner. CONSTITUTION:The toner is prepd. by mixing the compd. having the hydrocarbon chain and having 1-30cps melt viscosity at 100 deg.C, the coloring agent having <=5mum particle size, media, etc. by using a dispersing device such as ball mill, sand mill or attritor. The compd. having the hydrocarbon chain and having 1-30cps melt viscosity at 100 deg.C includes hydrocarbon of 12-50C, fatty acid and ester thereof, etc. The material for said media is exemplified by glass beads, steel balls, silica sand, alumina, zirconium, plastics, ceramics, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a toner used in electrostatic photography or magnetic recording.

[Prior Art] As an electrophotographic development method, powder cloud method, fur brush method, cascade development method, magnetic brush development method, etc. are conventionally known, but the toner used in these methods is made of natural or synthetic resin. A colored fine powder with dyes and pigments dispersed in it is used. For example, in the magnetic brush development method that is currently in widespread use, a two-component developer is used, which is a mixture of iron powder called a carrier and toner. In the case of such a two-component developer, maintenance and adjustment are required to prevent carrier contamination, toner concentration fluctuations, etc. in order to maintain good development.

Since this is complicated, a developing method using a one-component developer containing magnetic powder such as magnetite in the toner has begun to be developed and put into practical use.

If it is desired to retain the developed toner image, an operation called "fixing" is performed. Such fixing methods include a method in which the toner is melted and attached in a heat chamber, a method in which the toner is melted with a heated roller and simultaneously pressed onto the support surface, a method in which the toner is melted and attached using a solvent, and then the toner is melted and attached using a solvent. There are several known methods for fixing the image, such as applying a resin solution called a fixer onto the image and fixing it. It is becoming a law. The pressure fixing method requires that there is no danger of burning the copy sheet, that copying can be done without waiting time when the copying machine is turned on, that high-speed fixing is possible, and that the fixing device has a simple structure. There are many advantages such as.

However, while current pressure fusing methods have the above-mentioned major advantages, they also have several significant drawbacks. One is that the pressure for fixing is generally 30 to 40 kg/c.
A linear pressure of m is required, and in order to apply this much pressure, the fixing device is required to have considerable strength, which is undesirable as it increases the size and weight of the fixing device. Furthermore, it is extremely difficult to uniformly apply such pressure to the paper, which may cause the transfer paper to wrinkle or curl. Another drawback is that when such pressure is applied to the image using a roller, the surface of the image is smoothed, causing the image to become glossy and degrading the quality of the image.

In order to overcome these drawbacks, it is necessary to perform fixing with low energy, and toners that can be fixed with low energy are being actively developed. However, it has excellent fixing performance with low energy, does not cause offset to the pressure roller, and has stable development and fixing performance even after repeated use.
A practical toner with excellent storage stability that does not cause adhesion to the surface of a photoreceptor and does not cause aggregation or caking during storage has not been obtained.

[Problem that the invention attempts to solve] The present invention has been made in view of the points mentioned in -1-.

An object of the present invention is to provide a pressure-fixable toner that has high-performance fixing properties even with low energy.

Still another object of the present invention is to provide a fixable toner that exhibits little change in fixability with respect to pressure.

Still another object of the present invention is to be speed-independent and suitable for high-speed fixing! An object of the present invention is to provide a fixing toner.

Still another object of the present invention is to provide a fixable toner that does not cause offset to a pressure roller and does not cause adhesion to a metal sleeve or the surface of a photoreceptor.

Still another object of the present invention is to provide a fixable toner that has stable developing performance and fixing performance even after repeated use and does not cause aggregation or caking during storage.

[Means and effects for solving the problems] According to the present invention, there is provided a toner containing a colorant and a compound having a hydrocarbon chain having a melt viscosity of 1 to 30 cps at 100°C, Alternatively, a toner characterized in that secondary particles are dispersed in an amount of 51 L or less is provided.

Compounds having a hydrocarbon chain with a melt viscosity of 1 to 30 cps at 100°C include C12 to C5° hydrocarbons, fatty acids and their esters, metallic soaps, fatty alcohols,
These include polyhydric alcohols and their metal salts, their chlorides, fluorides, amides, and bisamides.

These materials are mixed with a coloring agent and atomized by a suitable method.

Specifically, the long-chain compounds having carbon chains of CI2 to C56 mentioned above include the following.

(1) Examples of normal and isoparaffins represented by CnH2n+ 2 (r+ ~12-50) and compounds having some unsaturated bonds therein include C2rn-Octacosane C31n-DotriacontaneC34n-He
xatriacontane, and also includes squalene C3oH5o and squalane [2,8,10,15,19,23hexamethyltetracosane (C3°HGI)].

(2) A fatty acid having a hydrocarbon chain as described above,
For example, there is something like the following table.

1-' (3) Alcohols and esters thereof can also be used (1), for example, as shown in the following table.

, 2-Alcohol (4) Also, chlorides of the substances listed in 2-2, such as chlorinated paraffin, can also be used.

(5) Amides and bisamides having hydrocarbon chains of CI2 to cSQ can also be used, for example as shown in the following table.

3 NN”-Melembisami These are commercially available singly or as a mixture.Generally, paraffin wax, microcrystalline wax, montan wax, ceremin wax, osikelite, carnauba wax, rice wax, shellac wax, and Zasol are used. It is known as wax, metal soap, amide wax, and lubricant.

Manufacturers and product names include Paraffin Fuchs (Nippon Oil), Paraffin wax (Hikisei!ll), Microwax (Nippon Oil), Microcrystalline wax (Nippon Oil), Hoechst wax (Hoec
hst AG), Diamond Wax (New Japan Chemical), Suntite (Seiko Chemical), Panacet (NOF)
etc.

Typical grades of paraffin wax include those shown in the table below.

Table 4 Paraffin wax and microwax (manufactured by Nippon Oil) Table 5 Paraffin wax (manufactured by Nippon Oil Co., Ltd.) Others such as Hoechst wax OP (partially saponified ester wax of montanic acid, Hoechst AG) E (ester of montanic acid) wax, Hoechst AG), GL3 (partially saponified synthetic wax, Hoechst AG), etc.

Of course, if necessary, several types of polymeric substances and some compounds having hydrocarbon chains may be used in combination.

When carrying out the present invention, such a compound having a hydrocarbon chain having a melt viscosity of 1 to 30 cps at 100° C. is used in an amount of 30% or more of the total resin component in the toner, preferably 50% or more. .

The present inventors further investigated pressure fixing toners that fix at low fixing pressures and found that conventionally, pressure fixing toners that fix at low fixing pressures, using low melting viscosity substances as their components, have been widely used. The dispersion method used for toners does not achieve uniform dispersion of the colorant, and when the toner particles are made into fine particles, there are particles in which no colorant is present inside the toner particles, or particles in which the colorant in the toner particles is 51L or more. The presence of many aggregated particles was observed, and this caused the aforementioned problems in developability, adhesion, fixation,
It has been found that disadvantages such as offset property and repeated use are exacerbated.

Furthermore, the inventors have discovered that the drawbacks of conventional toners can be overcome by dispersing the colorant particles in the toner particles so that the particle size is 5 IL or less, more preferably 2 IL or less.

An easy way to determine the dispersion state of the colorant in the toner is to embed the toner in a resin such as epoxy resin, cut it into pieces with a device such as a microtome, and observe it with a transmission microscope or electron microscope. can be known.

In order to obtain the toner fine particles of the present invention, it is preferable to disperse the toner components into 5 or less primary or secondary particles using a dispersion device using a media.

Various methods have been known for melting and dispersing toner components, such as a Miki roll and a twin-screw extruder kneader. In a toner containing a compound having a hydrocarbon chain and a colorant, the toner fine particles targeted by the present invention cannot be obtained, but the colorant contained therein exists as particles of five or more colors in the toner fine particles,
Furthermore, when the melt-dispersed amount is made into fine particles by a known method such as pulverization, the colorant becomes unevenly distributed in the particles or the component ratio becomes non-uniform. This causes nonuniformity or imbalance in the physical properties of each toner particle, such as electrostatic properties, magnetic properties, color properties, and smoothness, resulting in, for example, differences in the color of the toner itself due to insufficient dispersion of the colorant, or When images are repeatedly produced by a copying machine, differences in hue and density occur between the initial state and after repeated use.

For example, due to the uneven distribution of the colorant in the resin in the toner particles and the extremely different ratio of the colorant from one toner particle to another,
Since each particle has a different strength, various toner adhesion phenomena occur in the image forming process-1-, or image fixing properties become uneven, which tends to cause non-fixing, offset, etc.

In addition, for example, the uneven distribution and ratio of the colorant may vary from particle to particle, resulting in nonuniform electrostatic and magnetic properties of each toner particle (i.e., nonuniform or unstable developability, transferability, etc.). ), adverse effects such as changes in image quality and durability, such as changes in image density, are likely to occur.

In the present invention, these problems can be avoided by improving the dispersion of the colorant, and the toner performance can be improved.
I was able to make him do it.

Dispersion devices using media include ball mills, sand mills, attritors, and the like.

These machines can change the dispersion state by selecting the rotation speed and bead placement.

Various types of media can be used, but particularly for dispersion purposes for the purpose of the present invention, particle sizes of 0.5 to 20 mm are used.
It is preferable to have a single particle size or a mixture of various particle sizes.

As for the shape of the media, both spherical and amorphous media can be used.

As the material of the media, glass beads, steel poles, crushed sand, alumina, zirconium, plastics, ceramics, etc. are used.

In order to make toner after being dispersed, it is cooled and then finely divided using a so-called pulverizer or the like, or it is finely divided in a dispersed molten state and then cooled.

When a pigment is dispersed in a compound having a hydrocarbon chain having a low melt viscosity of 1 to 30 cps used in the present invention, the viscosity of the medium is low, so even once dispersed, it tends to aggregate immediately. Therefore, when the former method is used to form a toner, rapid cooling is required to ensure fixation before aggregation occurs, and operations such as dropping the toner onto a cooled plate after kneading are required.

However, the required cooling speed varies depending on the material, the particle size and characteristics of the intended toner, and the form at the time of kneading, and it is difficult to create a uniform state by cooling. Therefore, a more preferable method for producing toner is the latter method, in which the toner is finely divided in its dispersed molten state, and then cooled and taken out as particles.

The method of finely dividing the melt while it is in a molten state involves applying dispersion force to the melt in various media. For example, solid particles can be obtained by dispersing the melt in a hot air stream by means of discharge pressure or other hot air stream and then cooling the air stream. In addition, the melt is divided into small pieces by applying a stirring force, an emulsifier, a dispersant, etc. to the melt in a liquid medium such as hot water, and then the liquid medium is cooled and the liquid is separated using various clear liquid separation means. The solid particles can be obtained as solid particles by taking out the solid and performing operations such as drying as necessary.

ff such a method? If it is, it will be separated in a molten and dispersed state, so the pigment will be evenly dispersed in each particle and uniform particles will be obtained, and a toner with uniform and excellent properties will be obtained. .

This effect is especially great when a large amount of pigment with a relatively large particle size is added, and the effect is great when using magnetic materials, titanium white, etc.

The present inventors have also found that toner particles prepared by this method have a reduced possibility that colorant particles will appear on the surface of the toner particles. This makes the physical properties such as electrical properties of toner particles uniform,
It has many useful properties when made into toner, such as ease of encapsulation due to its smooth surface and chemical uniformity.

Furthermore, in the present invention, the toner fine particles can be coated with a resin and used as a microcapsule toner. In this case as well, in the presence of the colorant as in the toner of the present invention, the surface of the toner fine particles is homogeneous, so uniform coating is possible.
Microcapsules excellent as toner can be obtained.

Known resins can be used as the shell material of the microcapsule toner of the present invention, such as polystyrene, polyp-chlorostyrene, monopolymers of styrene and substituted products thereof such as polyvinyltoluene, and styrene-p-chlorostyrene. Copolymer, styrene-propylene copolymer, styrene-vinyltoluene copolymer, styrene-vinylnaphthalene copolymer, styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, methyl 1/-acrylic acid Butyl copolymer, styrene-octyl acrylate copolymer, styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer, styrene-α chlormethacrylate acid methyl copolymer, styrene-acrylocotrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene - Methylene copolymers such as isoprene copolymer, styrene-acryloni I/liluindene copolymer, styrene-maleic acid copolymer, styrene-maleic acid ester copolymer, polymethyl methacrylate-1・Polybutyl methacrylate, polyvinyl chloride, polyvinyl acetate, polyethylene, polypropylene, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin,
Terpene resins, phenolic resins, aliphatic or alicyclic hydrocarbon resins, aromatic petroleum resins, urea resins, melamine resins, etc. can be used alone or in combination.

Moreover, a known method is applied as the microencapsulation method. For example, a spray drying method, a liquid drying method, a phase separation method, a 1n-situ polymerization method, etc. can be used, and in order to give the toner of the present invention insulating properties and appropriate triboelectric charging characteristics, a multilayer shell structure is provided. It's okay.

Further, the toner of the present invention is used as a one-component magnetic toner, which is mixed with carrier particles such as iron powder, glass beads, nickel powder, and ferrite powder, as required, as a developer for electrical latent images. It can also be used in combination with hydrophobic colloidal silica fine powder for the purpose of improving the free-flowing properties of the powder, and abrasive fine particles such as cerium oxide for preventing toner adhesion.

The toner of the present invention can be applied to various low-energy fixing devices, such as low-pressure fixing devices and heat fixing devices that use less energy than conventional fixing devices.

[Example] Next, the present invention will be explained with reference to Examples.

Example 1 Paraffin with a melting point of 70°C (melt viscosity at 100°C: 13 cps) 80 parts by weight Polyethylene wax (average molecular weight 1500) 20 parts by weight Raven 3500 (carbon black) 10 parts by weight The above mixture was heated and melted, and a mixer with a rotation speed of 120 rpm was used. After mixing for 10 minutes, the mixture was placed in a ball mill pot equipped with a ceramic pole having a diameter of 5 mm to 15 mm and kneaded for 5 hours. The pot during kneading was heated to 110°C with oil.

After the kneaded material was taken out, it was supplied to a two-fluid nozzle equipped with a compressed air supply device heated to 200° C., atomized, cooled in air, and then collected.

The obtained particles were spherical particles with an average size of 12μ, and when they were embedded in epoxy resin, ultrathin sections were made with a microtome, and observed with a transmission electron microscope, the largest carbon black particle was 1.51L. Ta.

When the obtained particles were mixed with an iron powder carrier having an average particle diameter of 100 Jj- and a positive electrostatic latent image was developed, a clear image was obtained. Transfer the developed image to transfer paper and apply a linear pressure of 25 kg/
When the image was passed through a pressure roller of c amount, a completely fixed image was obtained.

Example 2 Paraffin with a melting point of 65°C 70 parts Carnauba wax 30 parts Magnetite (magnetic material)
60 parts of the above two mixtures were heated and melted and mixed for 10 minutes in a mixer at a rotational speed of 12 rpm, and then dispersed in a sand mill bottle filled with glass beads with a diameter of 2 mm. During kneading, the pot was heated to 120 ° C. with an electric heater. Ta.

The kneaded material was taken out and poured into a solution of 2 g of sodium dodecylbenzenesulfonate in 2000 parts of water heated to 95°C, stirred with 55 oorp soda to make the material fine particles, rapidly cooled, and then filtered and washed repeatedly. It was further dried to obtain fine toner particles. These fine particles were mixed with 0.3 parts of hydrophobic colloidal silica and used as a developer for Canon NP-1.
When applied to No. 20, clear images were obtained. The fixation was also perfect.

Furthermore, when the fixing device of the apparatus was replaced with an experimental apparatus having an average linear pressure of 15 kg, similar satisfactory results were obtained.

Comparative Example 1 A toner was prepared under exactly the same conditions as in Example 1 except that a ball mill was used.The average particle size of the obtained particles was +51L.
It was observed that the pigment in the toner was spherical particles, and the pigment in the toner was at most full.

When developing with this toner, only unclear images were obtained, and when a continuous copying test of 30 sheets was performed,
Gradually, the density decreased until no image appeared.

Comparative Example 2 The same procedure as in Example 2 was carried out except that polyethylene wax (viscosity at 100°C: 140 cps) was used instead of paraffin and carnauba wax.

The image density was low and at 15 kg/cm, the image after fixing could be easily removed by rubbing with a finger.

Example 3 70 parts of paraffin (8 cps) 30 parts of rice wax 10 parts of phthalocyanine blue The mixture was heated and melted and mixed for 15 minutes in a mixer at a rotational speed of 12 rpm, then placed in a sand mill bot filled with glass beads with a diameter of 1 mm. Dispersed. The pot is heated with an electric heater during kneading.
It was heated to 20°C. The kneaded material was taken out and poured into 1.8 g of silica dispersed in 1000 parts of water heated to 85°C, stirred at high speed to form fine particles, rapidly cooled, filtered and washed repeatedly, and further dried to form toner fine particles. I got it. This toner was mixed with a carrier and used as a developer.

The dispersed particles were 3JJ or less, and the developability and fixability were sufficient.

Comparative Example 3 The same procedure as in Example 3 was conducted except that 0.8 cps paraffin wax was used in place of 8 cps paraffin and rice wax. The size of the dispersed particles was 3IL, so the car development performance was insufficient, and the fixed image also came off when rubbed a little forcefully.

[Effects of the Invention] As described above, the toner of the present invention contains a colorant and a compound having a hydrocarbon chain having a melt viscosity of 1 to 30 cps at 100°C, so it exhibits pressure fixability and Since the colorant particles are dispersed in the toner particles in an amount of 5 pL or less, the colorant is uniformly distributed in the toner particles, the colorant ratio is constant among the toner particles, and the electrostatic properties and magnetic properties are Physical properties such as characteristics, color characteristics, and smoothness become uniform, and there is no color difference in the toner itself, or due to this, there are changes in hue and density between the initial and repeated use when printing images repeatedly with a copying machine. In addition, due to the uniformity of particle components, the strength of toner particles is constant, and various toner adhesion phenomena do not occur during the image forming process, and image fixability is uniform, with no unfixed or offset etc. will not occur.

Furthermore, as described above, since the electrostatic properties and magnetic properties are uniform, the developability, transferability, etc. are uniform or stable, and the film exhibits characteristics of excellent image quality and durability.

Claims (1)

[Claims] (1) A toner containing a colorant and a compound having a hydrocarbon chain having a melt viscosity of 1 to 30 cps at 100° C., characterized in that particles of the colorant are dispersed in a size of 5 μm or less.