JPH09211893A - Electrostatic charge image developing toner and its production - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a production method of an electrostatic charge image developing toner by which a coloring agent can be uniformly and finely dispersed to the neighborhood of the primary particles, in a binder resin, and to provide an electrostatic charge image developing toner with which an image of stable density can be obtd. without causing damages to a photoreceptor. SOLUTION: In the production method of an electrostatic charge image developing toner by melting and kneading a binder resin and a coloring agent, a kneading machine equipped with kneading screws comprising feeding vanes and backward feeding vanes and a means to cool the inner wall of the chamber and the screws is used. As for a dispersion assistant for the coloring agent, a higher alcohol expressed by the formula CH3 (CH2 )x CH2 OH, wherein (x) is an integer 28 to 49, is added for melting and kneading.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge developing toner containing a binder resin and a colorant for developing an electrostatic latent image and a magnetic latent image in electrophotography, electrostatic recording and the like. And a manufacturing method thereof.

[0002]

2. Description of the Related Art A toner for electrostatic charge development is obtained by melt-kneading a binder resin, a colorant, and if necessary, a release agent, a charge control agent and the like, cooling and solidifying, and then pulverizing and classifying. Furthermore, if necessary, a mixing process for adhering and fixing a fluidity-imparting agent, a charge control agent, a cleaning aid, a transfer aid, etc. on the toner surface and a sieving process for removing coarse powder are further provided. . In addition, after the sieving process or the like, a spheroidizing process may be provided in order to reduce the adhesive force of the toner, that is, to improve the powder fluidity, the developing property, and the transfer property.

In the toner, it is essential that the colorant, the release agent, the charge control agent, and other components are uniformly and finely dispersed in the binder resin. Due to the recent demand for full color and high image quality, in particular, higher dispersion of colorants has been required. The mixing degree and dispersibility of the colorant inside the toner are almost determined in the melt-kneading step in the production of the toner.

For example, if the colorant is unevenly distributed in the binder resin to cause poor dispersion, or the dispersion unit uniformly dispersed becomes large, the colorant remains unevenly distributed in the pulverizing step after melt-kneading, or is dispersed. Since the toner is pulverized while the unit is large, a toner having a non-uniform composition is produced. Further, when the dispersion is remarkably poor, particles having only a single component or particles having a composition uneven distribution are mixed in the toner, which causes broadening of the charge distribution and further reverse polarity. Further, since the toner is pulverized in the state of being exposed or released on the surface of the toner, the powder fluidity of the toner is remarkably reduced, which causes filming on the photoconductor.

When the unevenly distributed particles are colorants that are used in full color, the transparency is lowered and the color of the superposed bases does not appear, so that the desired color cannot be obtained,
Even for a single color, the color reproduction range is narrowed, the saturation is lowered, the coloring power is lowered, the density is lowered, and further the graininess is lowered. In addition, the difference between the colors of yellow, magenta, and cyan becomes large, and the strength of the binder decreases, which not only affects the fixability but also causes an obstacle such that the pulverization distribution tends to be broad. . In addition, since the distribution becomes very broad in terms of electrification, there are drawbacks such as background fogging, stains inside the machine, and short life.

When the particle component is a two-component black toner, sufficient charge cannot be obtained, and the charge distribution becomes very broad, and admix failure occurs, causing fog and stains inside the machine. cause. When the colorant is magnetic powder, free magnetic powder is generated from the aggregate of magnetic powder and the uneven distribution of magnetic powder, which damages the surface of the photoconductor in the copying machine or is retained on the developer carrier. Accumulated as it is,
There is a risk of gradually causing defects such as uneven density.

Recently, high quality, high reliability, and high speed have become the mainstream in all copying machines and printers.
Demands for toners include reduction in particle size and sharpening of particle size distribution. When the toner has a smaller particle diameter, the dispersion unit, uniformity, and particle size distribution of each constituent component are required to be more excellent than those of the conventional toner. It has become necessary to disperse the particles up to the vicinity of the secondary particles.

As a kneading device for dispersing these colorants and the like in the binder resin, a Banbury mixer having one or more rotary shafts such as screws, rotors and rolls,
A pressure kneader, an extruder, etc. are used, but a continuous screw type kneader (extruder) is mainly used from the viewpoint of improving continuous productivity such as high productivity and cost reduction.

Usually, a continuous screw type kneader used for producing toner is a combination of a feed screw section for feeding raw materials and a kneading section for mainly kneading, and two screw shafts are provided. It is arranged and surrounded by a cylindrical inner wall called a barrel or a chamber. The barrel can be heated and cooled with a heater, water, oil, etc., and the screw and chamber can be cooled with water, etc.

The continuous screw type kneader usually has two screws, and some screws rotate in the same direction and those rotate in different directions. In particular, a raw material self-heating type melt kneader equipped with a cooling chamber and a counter-rotating screw, which can apply high shear when a colorant or a release agent is highly dispersed, is preferably used.
In an apparatus using a rotary screw in the same direction, the viscosity of the raw material becomes too low, so that it is not possible to give a high share and high dispersion cannot be achieved.

As a method of increasing the viscosity of the raw materials to obtain a high shear, there is a method of adding water during kneading (Japanese Patent Laid-Open No. 6-58242).
1-50624). According to this method, the resin temperature during kneading is about 10 to 60 ° F (about 5.6 to 33.
3 ° C.), and dispersion can be improved. However, even if this method is adopted, compared to a raw material self-heating type melt kneader equipped with a cooling chamber and a counter-rotating screw, it is possible to sufficiently improve the dispersion of the colorant by adding water. I can't.

In a raw material self-heating type melt-kneader equipped with a cooling chamber and a counter-rotating screw, a toner raw material is supplied from a feed port and sent to a kneading section by a feed screw. The kneading part is composed of a feeding blade that tries to send the raw material to the discharge side and a returning blade that tries to return the raw material.The kneading part is caused by the pressure for the returning and the shearing force in the clearance part of the kneading screw and the chamber. Receives a high share, undergoes self-heating, melting, kneading, and is then discharged.

The kneading temperature at this time has a great influence on the dispersion quality of the colorant in the toner. If the kneading temperature is high, the viscosity of the raw material becomes too low to apply sufficient shear. As a result, the colorant has a large dispersion unit, and if the kneading temperature is too low, the wettability of the binder resin deteriorates, and the colorant cannot be sufficiently wetted. As a result, the aggregate is discharged from the kneader as it is or in a state of being unevenly distributed in the binder resin. Therefore, even in the raw material self-heating type melt-kneader equipped with the cooling chamber and the counter-rotating screw, the optimum kneading temperature should be maintained in order to obtain high dispersion and to obtain the target dispersion unit. Need to be kneaded.

For adjusting the kneading temperature, conventionally, the screw rotation speed, the kneading time of raw materials, the supply amount, the cooling water amount, the cooling temperature, the amount of water added at the time of kneading, etc. are used. The conventional toner can obtain high dispersibility which cannot be obtained by other kneaders by performing the above adjustment using a raw material self-heating type melt kneader equipped with a cooling chamber and a counter-rotating screw. it can. However, it is not possible to disperse the colorant in the vicinity of the primary particles.

In particular, due to recent demands for full color and high image quality, it is desired that the dispersion of the colorant is present in a state closer to the primary particles. On the other hand, as the particle size of the colorant is smaller and the non-dispersible (high surface area) colorant is beginning to be used, when using those raw materials,
Even the raw material self-heating type melt-kneader equipped with a cooling chamber and a counter-rotating screw which can relatively obtain high dispersion cannot disperse even the primary particles.

In an attempt to improve dispersibility by using these raw materials, a flushing coloring material is used, master batch kneading is performed, and a dispersant is added together with the raw materials. Even if a dispersant is used, the dispersion cannot disperse the primary particles. The method of using the flushing coloring material, the method of using the masterbatch kneading, and the method of several-order kneading cause not only the quality not obtained, but also a rise in raw material cost and production cost. . Further, all of the conventional dispersants not only adversely affect the charging characteristics and impair the full-color color characteristics, but also fail to obtain the desired dispersing effect.

For example, a method of adding a phthalocyanine derivative as a dispersant has been proposed (Japanese Patent Laid-Open No. 4-186).
370 publication). This method improves the dispersibility of the pigment to some extent, but cannot disperse it to the vicinity of the primary particles, hinders the color developability of the colorant, narrows the color reproducibility, and causes a decrease in saturation. Further, in the two-component toner that uses carbon black and the one-component toner that uses magnetic powder, the distribution of the charge amount remarkably expands, the background portion is fogged on the copy, and the in-machine stain becomes severe.
As described above, in the melt-kneading step, it is difficult to disperse the hardly-dispersed colorant to the vicinity of the primary particles even in the conventional kneading technique, particularly in the kneading technique for the purpose of high dispersion. .

[0018]

SUMMARY OF THE INVENTION Therefore, the present invention solves the above-mentioned drawbacks and provides an electrostatic charge developing toner capable of uniformly and finely dispersing a colorant in a binder resin up to the vicinity of primary particles. It is intended to provide a manufacturing method. Further, the present invention is intended to provide a toner for electrostatic charge development, in which a colorant is uniformly and finely dispersed in a binder resin, an image having a stable density can be obtained, and a photoreceptor is not hindered. Is.

[0019]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors succeeded in solving the problems by adopting the following constitution. (1) In a method for producing a toner for electrostatic charge development by melt-kneading a binder resin and a colorant, at least a plurality of kneading screws rotating in different directions are provided, and a chamber inner wall and / or the screw is provided. A method for producing a toner for electrostatic charge development, which comprises melt-kneading by adding a higher alcohol represented by the following general formula as a dispersion aid of the colorant using a kneader equipped with a cooling means. CH ₃ (CH ₂ ) _x CH ₂ OH (where x is an integer in the range of 28 to 48, preferably 32 to 42)

(2) The method for producing an electrostatic charge developing toner according to (1) above, wherein the kneading screw comprises a feed blade and a return blade. (3) The volume average particle diameter of the higher alcohol is 4 to 20 μm.
m, preferably 5 to 8 μm. The method for producing an electrostatic charge developing toner according to the above (1) or (2), which is characterized in that (4) 0.1 to 20.0 parts by weight, preferably 0.5 to 1 of the higher alcohol, relative to 100 parts by weight of the toner.
The above is characterized by being added in a range of 2.0 parts by weight.
(1) to (3) The method for producing a toner for electrostatic charge development according to any one of (3).

(5) Water is added in an amount of 0.1 to 10.0 parts by weight, preferably 1.0 to 5.0 parts by weight, based on 100 parts by weight of the kneading and feeding amount. 14)
7. The method for producing a toner for electrostatic charge development according to any one of 1. (6) The amount of heat exchange between the cooling chamber and the melt-kneaded product is 4.2 × 10 ^{5 to} 12.6 × 10 ⁵ J per unit weight of raw material.
/ Kg, preferably 7 × 10 ^{5 to} 12.6 × 10 ⁵ J /
The method for producing a toner for electrostatic charge development according to the above (5), characterized in that the toner is adjusted in the range of kg.

(7) When the diameter D of the kneading screw of the kneading machine, the length L of the kneading portion, and the length M of the entire screw are satisfied, the following formula is satisfied: (1) (6) The method for producing a toner for electrostatic charge development according to any one of (6). L = (0.2-0.9) M, preferably (0.4-0.
8) L / D = 3-8, preferably 4-6

(7) The kneading machine is adjusted so that the shear rate γ defined below falls within the range of 200 to 1200, preferably 500 to 900, and the shear strain S defined below is 5000 to 500. 30,000, preferably 7
The method for producing a toner for electrostatic charge development according to any one of the above (1) to (6), characterized in that the toner is adjusted to fall within the range of 000 to 18,000. γ = (π · D · N) / h × 60 (where D is the diameter of the kneading portion, N is the rotation speed of the kneading screw, and h is the clearance between the kneading screw and the inner wall of the chamber) S = γ × H (wherein, H is a kneading time) (8) An electrostatic charge developing toner produced by the production method described in any one of (1) to (7) above.

[0024]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an overall explanatory view of a raw material self-heating type kneader equipped with a counter-rotating screw used in the present invention, FIG. 2 is a sectional view of FIG. 1, and FIG. It is a figure for demonstrating the relationship between a kneading screw and a chamber. The kneading screw consists of a screw part that conveys the raw material, and a kneading part that mainly mixes the raw material with a strong shearing force.The kneading part feeds the raw material to the discharge side and the raw material. It consists of return vanes that try to return, and they are surrounded by a cylindrical inner wall called a chamber. In the kneader of FIG. 1,
Use two kneading screws in combination and rotate in opposite directions. There is a gap between the kneading screw and the inner wall of the chamber, which is called a tip clearance portion. In addition, the kneading screw and the chamber have a structure in which water, brine cooling water, or the like flows, so that the melted raw material can be cooled.

As shown in FIG. 1, the toner raw material is fed from the feed port and sent to the kneading part by the feed screw, and is subjected to strong pressure by the return blade and strong shearing force due to the rotation of the screw to be melted by self-heating. It The melted raw material is further subjected to strong shearing due to the rotation of the screw in the tip clearance portion in the latter half of the feeding blade and the returning blade portion, and the colorant is uniformly and finely dispersed. It is preferable that a vent port is provided in front of the kneading portion to remove air from the toner raw material to increase the filling rate. The higher the filling rate, the more effectively the shear force acts,
A feed neck can be prevented.

In the present invention, a kneading machine having a kneading screw consisting of a feed blade and a returning blade and having a chamber inner wall and means for cooling the screw is used.
By using a specific dispersion aid for the colorant, the colorant was successfully dispersed uniformly and finely. In particular, by using a higher alcohol having a volume average particle diameter of 4 to 20 μm, preferably 5 to 8 μm, it becomes possible to disperse the colorant up to the vicinity of the primary particles.

Although the reason for this is not clear, the higher alcohol and the colorant adhere to each other at the stage of mixing the raw materials before the kneading, and the higher alcohol and the binder resin have dispersibility (compatibility) at the time of melt kneading. Therefore, it is presumed that the colorant is uniformly and finely dispersed in the binder resin. In particular, it is considered that the colorant can be finely dispersed by using a higher alcohol having a large specific surface area and a small particle size. When the dispersant is dispersed in the binder resin, the dispersant needs to be finely dispersed to the extent that the toner characteristics are not deteriorated. However, the higher alcohols described above are finely dispersed in the binder resin. Since it exists in units, unlike conventional dispersants, it does not broaden the charge distribution, broaden the particle size distribution, impair the powder flowability, or impair the color characteristics especially in full-color toners. .

As the higher alcohol of the present invention, one represented by the following formula is used. CH ₃ (CH ₂ ) _x CH ₂ OH (where x is an integer in the range of 28 to 48, preferably 32 to 42) When X is less than 28, the dispersion of the colorant is good but the melting point is low. , Filming on the photoconductor occurs. Further, when X exceeds 48, the colorant is insufficiently dispersed.

To adjust the particle size of these higher alcohols,
Mechanical crushers, jet crushers, etc. are used,
The amount of fine powder and the amount of coarse powder may be adjusted by classifying with an inertial classifier, a centrifugal classifier, or the like. The amount of higher alcohol to be added is appropriately in the range of 0.1 to 20.0 parts by weight, preferably 0.5 to 12.0 parts by weight, based on 100 parts by weight of the toner.

Water was added during the melt-kneading, and the amount of heat exchange with the cooling chamber was 4.2 × 10 ⁵ per unit weight of raw material.
By adjusting in the range of ˜12.6 × 10 ⁵ J / kg, it becomes possible to allow the colorant dispersion to exist in the state of almost primary particles. The reason is not clear, but by adding water, the kneading temperature of the entire raw material can be lowered first, and as a result, the viscosity of the binder resin can be increased and a high market share can be obtained. When the water evaporates, the generated steam mixes with the raw material to increase the filling rate, the contact probability between the molten resin and the wall of the cooling chamber increases, and a large amount of heat exchange is performed through the wall of the cooling chamber. Here, considering the gap between the tip of the kneading screw and the inner wall of the chamber, that is, the small area of the tip clearance, the large amount of heat exchange with the chamber means that the viscosity of the binder resin in that area is high. As a result, it seems that a high market share can be given to raw materials.

In order to increase the viscosity of the kneading resin and obtain a high shearing stirring force by adding heat to the cooling chamber and heat-melting and kneading the mixture by utilizing latent heat of vaporization, a kneading supply amount of 100 wt. 0.1 to 10.0 parts by weight, preferably 1.0 to 5.0 parts by weight of water is added to the parts, and the heat exchange amount between the cooling chamber and the melt-kneaded product is 4 per unit weight of the raw material. 2.2 × 10 ^{5 to} 12.6 × 10 ⁵ J / k
g, preferably 7.0 × 10 ^{5 to} 12.6 × 10 ⁵ J /
Adjust to the kg range. If the amount of water added exceeds 10.0 parts by weight, the water will not be completely evaporated and will be wasted. Also, if the amount of water vapor present inside the kneader becomes too large, the apparent viscosity of the resin will decrease and it will not be possible to apply a strong share, and it will be difficult to discharge the water vapor and the water vapor will return to the supply side. , A feed neck (a clogging of raw material supply) is likely to occur.

The amount of heat exchange can be calculated from the following equation by measuring the temperature difference between the inlet and outlet of the refrigerant, the specific heat and specific gravity of the refrigerant, its flow rate, and the amount of the raw material supplied. . Q = C × W × ρ × Δt × (1 / H) where C: specific heat of refrigerant (g / kg ° C.) W: flow rate of refrigerant (m ³ / hr) ρ: specific gravity of refrigerant (kg / m ³ ) Δt: Temperature difference between the inlet and outlet of the chamber (° C) H: Raw material supply (kg / hr)

The temperature of the resin during kneading depends on the heat generated by shearing and
It will be kept constant by the heat absorption from the chamber and screw. The kneading temperature is preferably adjusted within the range of + 20 ° C to + 100 ° C with respect to the melting temperature of the binder resin. When the melting temperature of the binder resin is lower than + 20 ° C., the viscosity of the resin is too high, so that the coloring agent is difficult to wet and the dispersion is insufficient. Melting temperature of binder resin +100
If the temperature exceeds ℃, the viscosity of the resin becomes too low and kneading shearing force is less likely to be applied, the dispersion of the colorant may not proceed, and the resin itself may be decomposed.
Inconveniences such as the need for further cooling arise.

The kneading machine used in the present invention has a diameter D of the kneading screw, a length L of the kneading portion, and a length M of the entire screw. Shearing force can be applied, and the colorant can be dispersed uniformly and finely. L = (0.2-0.9) M, preferably (0.4-0.
8) M L / D = 3 to 8, preferably 4 to 6

When the length L of the kneading portion exceeds 0.9 times the length M of the entire screw, the length of the raw material feeding screw portion becomes short, and the ability to feed the raw material to the kneading portion becomes insufficient. It is easy to cause a clogging (feed neck) in the supply section. In addition, the total length M of the screw is 0.2
If it is less than twice, the shearing time becomes short, and it becomes impossible to obtain the target high dispersion. Ratio of the length L of the kneading part to the diameter D of the kneading screw L /
When D is less than 3, the kneading time becomes too short and L / D
When is greater than 8, a feed neck is likely to occur.

Further, the kneading portion has a feed blade and a return blade, and the length ratio between the feed blade and the return blade is 0.5 to 2. A range of 0, preferably 0.75 to 1.5 is suitable. The kneading screw of the kneading machine of the present invention has two or three blades. The ratio of the length of the wings from the center of the abdomen is 0.3-0.8, preferably 0.5-
The range of 0.75 has a great effect on the dispersion of the colorant up to the vicinity of the primary particles.

In the present invention, the kneader has a shear rate γ defined below of 200 to 1200, preferably 500 to 90.
It is desirable to adjust so that it falls within the range of 0, and the shear strain S defined below falls within the range of 5,000 to 30,000, preferably 7,000 to 18,000. γ = (π · D · N) / h × 60 (where D is the diameter of the kneading portion, N is the rotation speed of the kneading screw, and h is the clearance between the kneading screw and the inner wall of the chamber) S = γ × H (In the formula, H is the kneading time)

The present invention can be applied to both one-component toner and two-component toner. As the binder resin for the toner, a thermoplastic resin usually used for toner can be used. Specifically, styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and isobutylene, vinyl acetates such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate, and methyl (meth) acrylate. , Ethyl (meth) acrylate, butyl (meth) acrylate, dodecyl (meth) acrylate, octyl (meth) acrylate, (meth)
Α-methylene aliphatic monocarboxylic acid esters such as phenyl acrylate, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl butyl ether,
Examples thereof include vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone, and homopolymers or copolymers thereof.

Particularly, as typical binder resins, polystyrene, styrene / alkyl acrylate copolymer, styrene / alkyl methacrylate copolymer, styrene / acrylonitrile copolymer, styrene / butadiene copolymer, styrene Examples thereof include maleic anhydride copolymer, polyethylene and polypropylene. further,
Examples thereof include polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin and paraffin wax.

As the binder resin as described above, one having a structure and a molecular weight such that the melting temperature is in the range of 80 to 150 ° C. is suitable. In particular, styrene / acrylic resins and polyester resins are preferably and positively used.
The melting temperature is 1 × the melt viscosity on the apparent viscosity curve.
It means the temperature at 10 ⁴ Pas. The measurement of melt viscosity is
Using a flow tester CFT-500F type manufactured by Shimadzu Corporation, a temperature apparent viscosity curve was obtained under the following conditions. Temperature rising rate 3.0 ° C / min Starting temperature 80.0 ° C Ultimate temperature 150.0 ° C Measurement interval 3.0 seconds Preheating time 300.0 seconds Cylinder pressure 10.0 kgf / cm ² Die hole diameter 1.0 mm Die length 1.0 mm

A releasing agent may be added to the toner of the present invention for the purpose of preventing fixing offset. The addition of the release agent does not hinder the dispersion of the colorant, and the toner production method of the present invention also makes the dispersion of the release agent very fine. As the release agent, paraffins having 8 or more carbon atoms, polyolefins and the like are preferable, and examples thereof include paraffin wax, paraffin latex, microcrystalline wax, low molecular weight prepropylene and low molecular weight polyethylene. These may be used alone or in combination. Can be used. The range of the softening point of the release agent is 110-110.
It is 150 ° C. When two or more releasing agents are used, it is preferable to adjust and set the temperature for the releasing agent having the lowest softening point. The softening point is measured according to JISK22.
According to the 07 softening point test method (ring and ball method).

Examples of the colorant for the toner of the present invention include known colorants such as carbon black, phthalocyanine copper-based cyan colorant, azo-based yellow colorant, azo-based magenta colorant, and quinacridone-based magenta colorant. it can. Specifically, aniline blue, calcoil blue, chrome yellow, ultramarine blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate,
Lamp Black, Rose Bengal, CI Pigment Red 48: 1, CI Pigment Red 12: 2, CI Pigment Red 57: 1, CI Pigment Yellow 97, CI Pigment Yellow 12, CI Pigment Blue 15: 1, CI Pigment Blue 15: 3 Etc. can be mentioned. Further, the above water-containing paste can also be used.

When used as a magnetic toner,
All or part of the above coloring agent can be replaced with magnetic powder. The amount used as the magnetic powder is in the range of 20 to 80% by weight, preferably 40 to 60% by weight.
As the magnetic powder, known magnetic materials that have been used so far can be used. Specifically, simple metals such as iron, cobalt, nickel and alloys thereof, Fe ₃ O ₄ ,
γFe ₂ O ₃ , metal oxides such as cobalt-added iron oxide, M
What is formed by various ferrites, such as n-Zn ferrite and Ni-Zn ferrite, is used. The average particle diameter of the magnetic material is suitably in the range of 0.05 to 0.5 μm. Incidentally, in order to impart chargeability and dispersibility, it is also possible to use those subjected to a surface treatment with a titanate coupling agent or a silane coupling agent, but in the present invention, a magnetic powder having no surface treatment is more effective. Is larger.

If necessary, a charge control agent can be added to the toner of the present invention. In particular,
Fluorine-based surfactants, metal complexes of salicylic acid, metal-containing dyes such as azo-based metal compounds, polymeric acids such as copolymers containing maleic acid as a monomer component, quaternary ammonium salts, azo-based dyes such as nigrosine, etc. Can be added.

In the present invention, the binder resin, the colorant, the higher alcohol, and if necessary, the release agent, the charge control agent and the like are premixed in a mixer and kneaded by the above kneading method, followed by rolling,
It is possible to grind and classify through steps such as cooling, crushing and crushing. Rolling is usually done by the roll type used in the rubber industry and toner industry.
A type that can be cooled with brine or the like is used from the viewpoint of adhesion and dispersion. The thickness of the rolled slab varies depending on the production scale, but the roll gap and the like are generally adjusted to be 1 to 20 mm.

Cooling of the kneading slab includes a type of applying cooling air, a type of immersing in cooling water, a type of sandwiching a rolled slab with a belt, and a type of cooling the upper and lower surfaces of the belt with cooling water or the like. The belt type cooling type is widely used especially from the viewpoint of dispersion of the release agent. For crushing, a jet crusher, a mechanical crusher or the like can be used, but the type thereof does not matter. It is also possible to use an internal collision mechanism or a coarse powder classifier that constitutes a closed circuit. In the classification step, a centrifugal classifier or an inertial classifier can also be used. The size of the particles is adjusted by pulverization and classification so as to have a volume average particle size of 3 to 15 μm, preferably 5 to 8 μm.

In the toner of the present invention, after classification, an inorganic fine powder such as titania, silica or alumina is used to improve the fluidity characteristics.
It can be added and mixed for the purpose of charge control and improvement of development transferability. The surface of the above-mentioned silica, titania or the like can be treated with a silane coupling agent, a surfactant, a quaternary ammonium salt or the like. Further, if necessary, a substance for improving charge exchange such as carbon black or tin oxide can be used. It is also possible to improve the transfer / developing property by using silica, titania or the like having a large particle size.

Further, if necessary, a cleaning aid such as polystyrene fine particles, polymethylmethacrylate fine particles and polyvinylidene fluoride fine particles may be added.
As the mixer used, all known mixers can be used, and examples thereof include a V-type blender, a Henschel mixer, and a Loedige mixer. Further, the toner of the present invention may be provided with a sieving step for the purpose of removing coarse particles, if necessary. Examples of the sieving machine used include a gyro shifter, an electric sieving machine, and a high bolter.

The toner of the present invention can be used as a magnetic one-component developer containing magnetic powder or as a magnetic two-component developer using a carrier. Alternatively, it can be used as a non-magnetic one-component developer using a colorant or as a non-magnetic two-component developer using a carrier without containing magnetic powder. When used as a two-component developer, as a carrier, iron powder, glass beads, ferrite powder, nickel powder, magnetite powder, or those coated with a resin, resin and a charge control agent are magnetic materials. It is also possible to use a resin dispersion type carrier by kneading and pulverizing and classifying.

[0050]

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Example 1 Binder resin (polyester, Mw = 15,000, Tg = 60 ° C.) 90 parts by weight Phthalocyanine blue (Blue 15: 3, primary particle size = 0.02 μm) 5 parts by weight Higher alcohol (CH ₃ (CH ₂ ) ₃₅ CH ₂ OH, volume average diameter 200 μm) 5 parts by weight

The above composition was mixed and stirred to prepare a kneading material. Then, the kneading was performed using a chamber cooling type kneading screw counter-rotating raw material self-heating type continuous kneader. The setting of the kneading machine is L = 0.25m,
M = 0.38m, D = 0.05, N = 916, h = 3m
m and H = 18s. The temperature of the kneaded material at the outlet is
The temperature was 153 ° C., and the heat exchange amount of the chamber per unit weight of raw material was 3.4 × 10 ⁵ J / kg. The obtained kneaded product was rolled and cooled by a water-cooling type cooling conveyor, and then pulverized and classified to obtain toner particles having a volume average particle size of about 7 μm. As external additives to the toner particles, 1.0% by weight of anatase-type titania treated with isobutyltrimethoxysilane having an average particle diameter of 20 nm and 0.8 weight of silica treated with a silicone oil having an average particle diameter of 50 nm are used with respect to the toner weight. %, And mixed with a 5 liter Henschel mixer (manufactured by Mitsui Miike Koki Co., Ltd.) for 10 minutes to obtain a toner of Example 1. The particle size distribution was measured by Coulter Multisizer II manufactured by Coulter Electronics.

Example 2 An example was carried out under exactly the same conditions as in Example 1 except that the volume average diameter of the higher alcohol (CH ₃ (CH ₂ ) ₃₅ CH ₂ OH) used in Example 1 was changed to 7 μm. No. 2 toner was prepared.

[Example 3] At the time of kneading, 1.0% by weight of water was added to the raw material supply amount, and the heat exchange amount with the chamber per unit weight of the raw material was adjusted to 5.8 x 10 ⁵ J / kg. Example 3 The toner of Example 3 was manufactured under exactly the same conditions except for the above. The resin temperature during kneading was 135 ° C.

Example 4 A toner of Example 4 was prepared under exactly the same conditions as in Example 2 except that 1.0% by weight of water was added to the raw material supplied at the time of kneading.

Comparative Example 1 A continuous screw twin-screw extruder (Toshiba Kikai Co., Ltd.) in which the same composition as in Example 2 was agitated and mixed, and thereafter, two screws were provided and the screws were rotated in the same direction. Manufactured by TEM-50) and melt-kneaded while adding 3.0% by weight of water to the raw material supply amount, and the obtained kneaded product is pulverized, classified, mixed and sieved in the same manner as in Example 2, A toner of Comparative Example 1 was prepared. At this time, the kneading resin temperature was 123 ° C. and the barrel setting temperature was 120 ° C. The amount of heat exchange in the chamber could not be measured because it was heated, but it is a very small value.

Example 5 Binder Resin (Styrene / Acrylic Copolymer, Copolymerization Ratio = 85/15, Mw = 130,000, Tg = 61 ° C., Melting Temperature = 87 ° C.) 75 Parts by Weight Colorant (Carbon Black Primary particle size = 13 nm) 10 parts by weight Higher alcohol (CH ₃ (CH ₂ ) ₄₅ CH ₂ OH, volume average diameter 80 μm) 8 parts by weight Release agent (polypropylene wax) 5 parts by weight

After the above composition was mixed and stirred in a 75 liter Henschel mixer, a chamber-cooling kneading screw counter-rotating raw material self-heating type continuous kneader (same as in Example 1) was used. Kneading was performed while adding 1.0% by weight of water to the raw material supply amount. The temperature of the kneaded material at the discharge port was 136 ° C., and the amount of heat exchange with the chamber per unit weight of raw material was 7.2 × 10 ⁵ J /
kg. The obtained kneaded product was rolled and cooled by a water-cooling type cooling conveyor, and then pulverized by a jet mill with a coarse powder classifier made by Fuji Xerox Co., Ltd. and a collision machine (SJ-9 made by Fuji Xerox Co., Ltd.), and further inertia The particles were classified by a type classifier to obtain toner particles having a volume average particle size of about 9 μm. As an external additive to the toner particles, hexamethyldisilane-treated silica having an average particle diameter of 12 nm with respect to the toner weight is 0.3% by weight with respect to the toner weight, and a volume average diameter of 0.2 μm is used as a cleaning aid. 0.5% by weight based on the weight of toner is added to the toner, mixed with a 5 liter Henschel mixer (manufactured by Mitsui Miike Koki Co., Ltd.) for 10 minutes, and further sifted using a vibration sieving machine. A toner of Example 5 was obtained.

Example 6 The volume average diameter of the higher alcohol (CH ₃ (CH ₂ ) ₄₅ CH ₂ OH) used in Example 5 was changed to 15 μm, and the addition amount was 2 parts by weight. A toner of Example 6 was manufactured under the same conditions as in Example 5 except that the weight was 83 parts by weight.

Comparative Example 2 A continuous screw extruder (manufactured by Toshiba Machine Co., Ltd.) having the same composition as in Example 6 and stirring and mixing, and having two screws, the screws rotating in the same direction as each other. TEM-50) was used to melt-knead while adding 3.0% by weight of water to the raw material supply, and the resulting kneaded product was pulverized / classified / mixed / sieved in the same manner as in Example 5 to obtain a comparative example. No. 1 toner was prepared. The kneading resin temperature at this time was 134 ° C., and the setting temperature of the barrel was 120 ° C. Since the amount of heat exchange in the chamber is heating,
It could not be measured, but it is a very small value.

(Preparation of Developer) Using 8 parts by weight of the toners obtained in Examples 1 to 4 and Comparative Example 1 and 0.7% by weight of a silicone resin corresponding to 0.7% by weight of a ferrite core having an average particle size of 45 μm, kneading was performed in a kneader device. A developer was prepared by mixing 93 parts by weight of the carrier thus coated with V in a V blender, and 7 parts by weight of the toner obtained in Examples 5 to 6 and Comparative Example 2 and a ferrite core having an average particle size of 60 μm. 0.1
A copolymer of vinylidene fluoride, methyl methacrylate and trifluoroethylene corresponding to the weight% (copolymerization ratio 5/85
/ 10) was mixed with 93 parts by weight of the carrier, which was kneaded and coated by a kneader device, with a V blender to prepare a developer.

(Colorant Dispersion Test of Toner) The slab after kneading the toner is 0.2 μm with a cutter such as Mictorome.
The sample was cut into pieces having a thickness of about 5 times and photographed with a transmission electron microscope at a magnification of 5000. The area% of the aggregate of the colorant in the range of 20 cm × 40 cm was measured by an image analyzer having a visual field of 40 μm × 80 μm. Here, as the aggregate, particles having a particle diameter of 0.05 μm or more were counted. The area% is small in the case where the number of aggregates is small and the dispersion has progressed to the vicinity of the primary dispersion diameter. Those having an area% value of 2.5% or less were defined as near the primary dispersion diameter. The measurement results are shown in Table 1.

(Measurement of toner release agent dispersion diameter (μm))
The slab after kneading the toner is cut into a thickness of about 0.2 μm with a cutter such as Mictorome, and is cut with a transmission electron microscope.
A 000 times photograph was taken, and the particle size (equivalent circle diameter converted from the area) of the release agent in the range of 20 cm × 40 cm was measured with an image analyzer having a visual field of 40 μm × 80 μm. Here, as the release agent, those having a particle size of 0.1 μm or more were counted. The better the dispersion, the smaller the equivalent circle diameter. In addition, those having a value of equivalent circle diameter of 0.5 μm or less were determined as good dispersion. The measurement results are shown in Table 1.

(Charge Property Test of Developer) Charge amount and charge amount distribution of the developer at the initial stage when the above developer was applied to A-Color 635M / C manufactured by Fuji Xerox Co., Ltd. and after running evaluation of 100,000 sheets. Was measured using TB-200 (manufactured by Toshiba), and the results are shown in Table 1.

(Measurement of OHP Transmittance) The OHP transmittance is a ratio (%) of light transmitted by irradiating an image fixed on an OHP sheet with light having a frequency corresponding to the color. is there. The better the dispersion of the colorant is, the higher the proportion of light that is transmitted, and the higher the proportion of the light that is transmitted, the better the OHP suitability is, the brighter the fixed image is, and the better the coloring of the colorant is. The measurement results are shown in Table 1.

(Maintaining image quality and evaluating surface of photoconductor) The above-mentioned developer was used as A-Color 635M manufactured by Fuji Xerox Co., Ltd.
/ C was used to make an image quality test by copying 100,000 sheets under the environment of 20 ° C. and 40% RH. In the image quality test, the image density after copying 100,000 sheets and the degree of fog in the background portion were evaluated.
The image density used was Macbeth density. 1 in the table.
0GS indicates that the original document whose density is 1.0 was used.

The evaluation criteria of the fog in the background part are as follows: ⊚: no fog, ○: almost no fog, Δ: slight fog, ×: fog, and XX: considerably fog. . Further, the surface of the photoconductor after copying 20,000 sheets was observed, and the scratches on the photoconductor due to the adhesion of the developer were visually evaluated. ⊚ indicates that the photoreceptor surface is very good, ∘ indicates that it is good, and x indicates that the surface condition is poor.

[0067]

[Table 1]

[0068]

INDUSTRIAL APPLICABILITY As described above, the present invention uses a screw-differential rotation type chamber cooling raw material self-heating type melt-kneading machine, and by adding a specific higher alcohol as a dispersion aid, a colorant or the like can be obtained. It is possible to obtain a toner in which the above is uniformly and finely dispersed in the binder resin to almost the vicinity of the primary particles, and in particular, the dispersibility can be improved by setting the particle size of the higher alcohol to 4 to 20 μm in volume average diameter. The amount of heat exchange from the chamber per unit weight of the raw material can be 4.2 × by adding water at the time of melt-kneading.
By adjusting the amount in the range of 10 ^{5 to} 12.6 × 10 ⁵ J / kg, it is possible to give a high shear to the raw material and further improve the dispersion of the colorant, and as a result, The distribution is sharp, good charging characteristics can be maintained, and in full color, transparency, coloring power, saturation, and color reproducibility are excellent, and high image quality can be obtained. In addition, there is no background fog, stains inside the machine, and images with stable density can be obtained continuously. Further, the developer according to the present invention can provide an excellent developer which does not impair the photoreceptor.

[Brief description of drawings]

FIG. 1 is an overall explanatory view of a raw material self-heating type kneader equipped with a counter-rotating screw used in the present invention.

FIG. 2 is a sectional view of FIG.

FIG. 3 is a diagram for explaining the relationship between the kneading screw and the chamber of the counter-rotating screw according to the present invention.

Claims (3)

[Claims] 1. A method for producing a toner for electrostatic charge development by melt-kneading a binder resin and a colorant, comprising at least a plurality of kneading screws rotating in different directions,
Further, a kneader equipped with a means for cooling the inner wall of the chamber and / or the screw is used, and a higher alcohol represented by the following general formula is added as a dispersion aid for the colorant, and the mixture is melt-kneaded. Method of manufacturing toner for electrostatic charge development. CH ₃ (CH ₂ ) _x CH ₂ OH (where x is 28
An integer in the range of ~ 48) 2. The volume average particle size of the higher alcohol is 4
It adjusts to the range of -20 micrometers.
A method for producing the electrostatic charge developing toner as described above. 3. An electrostatic charge developing toner produced by the production method according to claim 1.