JP2003255599A - Method for manufacturing toner and toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner in which wax particles are finely dispersed and to provide a method for manufacturing the toner. <P>SOLUTION: The method for manufacturing the toner includes: a process of kneading a source material 5 comprising at least a resin, a colorant and wax by using a kneading machine 1 to obtain a kneaded product 7; and a process of cooling the kneaded material 7. The kneading machine 1 is equipped with a process part 2 to carry the source material 5 while kneading and is also provided with an extrusion port 3 where the kneaded material 7 is extruded in the lower part of the side face of the process part 2. The source material is kneaded by revolution of screws 22, 23 in the process part 2. The screw 22 is provided with a helical groove 221 and a groove 222 having the revolving direction different from that of the groove 221. The inversion part 223 of the revolution direction where the revolving directions of the helixes are inversed is positioned almost above the extrusion port 3. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner manufacturing method and a toner.

[0002]

2. Description of the Related Art A number of electrophotographic methods are known, but generally, a step of forming an electric latent image on a photoconductor by various means utilizing a photoconductive substance (exposure). Step), developing the latent image with toner, transferring the toner image to a transfer material such as paper, and fixing the toner image with heat, pressure, solvent vapor, or the like. ing.

Various methods and devices have been developed for the final step of fixing the toner image on a sheet such as paper. The most popular method at present is a pressure heating method using a heating roller.

In the pressure heating method using a heating roller, fixing is performed by allowing the toner image surface of the sheet to be fixed to pass under pressure while contacting the surface of a heating roller having a surface formed of a material having releasability for toner. It is one. In this method, the surface of the heating roller and the toner image on the sheet to be fixed come into contact with each other under pressure, so the thermal effect at the time of fusing the toner image on the sheet to be fixed is extremely good, and quick fixing is required. And is very effective in high speed electrophotographic copying machines. However, in the above method,
Since the surface of the heating roller and the toner image are in contact with each other in a molten state under pressure, a part of the toner image adheres to and transfers to the surface of the fixing roller and retransfers to the next sheet to be fixed, which causes a so-called offset phenomenon. , The sheet to be fixed may be soiled. One of the essential conditions of the heating roller fixing method is to prevent toner from adhering to the surface of the heat fixing roller.
It is supposed to be.

Conventionally, for the purpose of preventing the toner from adhering to the surface of the fixing roller, for example, the roller surface is formed of a material excellent in releasability from the toner, such as silicone rubber or fluorine resin, and the surface is prevented from being offset. Also, in order to prevent the roller surface from fatigue, the roller surface is coated with a thin film of a liquid having a good releasing property such as silicone oil. However, this method is extremely effective in preventing toner offset, but has a problem that the fixing device becomes complicated because an apparatus for supplying an offset preventing liquid is required. . Therefore, the direction of preventing the offset by supplying the offset preventing liquid is not preferable, and the present situation is that the development of a toner having a wide fixing temperature range and high offset resistance is desired.

For the purpose of preventing the occurrence of such an offset phenomenon, a wax having excellent releasability is added to the toner.

The toner containing wax is usually manufactured as follows. First, the resin as the main component (hereinafter,
Also simply referred to as "resin". ), A colorant, and a wax are kneaded at a temperature equal to or higher than the softening point of the resin to obtain a kneaded product. The kneaded product thus obtained is cooled to a temperature equal to or lower than the melting point of the resin, then pulverized, and if necessary, an additive (external additive) is added to produce a desired toner.

By the way, it is known that wax generally has low compatibility with the resin which is the main component of the toner. Therefore, for the purpose of sufficiently finely dispersing the wax,
In the production of toner, a kneading process is carried out to sufficiently knead the raw materials. However, in the conventional manufacturing method, the wax particles in the finally obtained toner particles may not be sufficiently miniaturized even if such kneading treatment is sufficiently performed.

As described above, if the wax particles cannot be sufficiently miniaturized (if the wax particles become coarse), the exudation of the wax occurs remarkably, and the toner becomes
The durability is low, such as easy adhesion (filming) to the photoconductor.

Further, in a toner in which the wax particles are coarsened, the mechanical strength is lowered and the durability is also deteriorated.

Further, a toner having coarse wax particles has a problem that a so-called fog phenomenon easily occurs.

The above-mentioned problems due to the coarsening of the wax particles are particularly remarkable in color toners required to have sharp melt properties and toners used in printers having an oilless fixing device.

[0013]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner in which wax particles are finely dispersed and a method for producing the toner.

[0014]

The above objects are achieved by the present invention described in (1) to (18) below.

(1) At least a resin, a colorant,
A method for producing a toner, comprising a step of kneading a raw material containing wax with a kneader to obtain a kneaded product, and a cooling step of cooling the kneaded product, wherein the kneader conveys the raw material. And a kneading process part for kneading, and a side face of the process part is provided with an extrusion port through which the kneaded product is extruded, and the kneaded product is extruded from the extrusion port. .

(2) The method for producing a toner according to (1), wherein the kneaded product is extruded in a direction substantially perpendicular to the direction in which the raw material is conveyed in the process section.

(3) The method for producing a toner according to (1) or (2), wherein the extrusion port is provided substantially below the process section and the kneaded product is extruded substantially vertically downward.

(4) One or two process parts are provided.
The method for producing a toner according to any one of the above (1) to (3), which has at least two screws and conveys the raw material in a rotation axis direction of the screws.

(5) The method for producing a toner according to the above (4), wherein an extrusion direction of the kneaded product extruded from the extrusion port and a rotation axis direction of the screw are substantially vertical.

(6) The screw has a spiral groove formed on the outer periphery thereof, and has a portion in which the rotation direction of the spiral of the groove is different from the axial direction of the screw. The method for producing a toner according to 5).

(7) The method for producing a toner as described in (6) above, wherein the kneaded product is extruded from the extrusion port provided in the vicinity of a portion where the rotation direction of the spiral of the groove with respect to the axial direction of the screw is reversed.

(8) Any one of the above (1) to (7), wherein the extrusion port has a portion whose cross-sectional area increases continuously or intermittently along the direction in which the kneaded product is extruded. The method for producing a toner according to claim 1.

(9) The method for producing a toner according to any one of (1) to (8), wherein the content of the wax in the raw material is 2.0 wt% or more.

(10) The method for producing a toner according to any one of the above (1) to (9), wherein the average particle diameter of the wax in the kneaded product after the cooling step is 1.5 μm or less.

(11) The softening point of the wax is T
_s [° C.], where T _m [° C.] is the melting point of the resin, T
_The method for producing a toner according to any one of (1) to (10) above, which satisfies the relationship of _s <T _m .

(12) The temperature of the kneaded product near the extrusion port is T ₁ [° C.], the temperature of the kneaded product immediately after the completion of the cooling step is T ₂ [° C.], and the kneaded product is discharged from the extrusion port. When the time required from the extrusion to the completion of the cooling step is t [seconds], (T ₁ −T ₂ ).
The method for producing a toner according to any one of the above (1) to (11), which satisfies the relationship of / t ≧ 5 [° C./sec].

(13) The time t required from the extrusion of the kneaded product from the extrusion port to the completion of the cooling step is 15 seconds or less, according to any one of the above (1) to (12). Toner manufacturing method.

(14) The method for producing a toner according to any one of (1) to (13) above, which has a step of pulverizing the kneaded product.

(15) The method for producing a toner according to any one of (1) to (14) above, wherein the toner is a color toner.

(16) A toner manufactured by the method according to any one of (1) to (15) above.

(17) The toner according to the above (16), which has an average particle diameter of 4 to 12 μm.

(18) The toner according to the above (16) or (17), wherein the average particle diameter of the wax in the toner is 1.5 μm or less.

[0033]

BEST MODE FOR CARRYING OUT THE INVENTION The toner and the method for producing the toner of the present invention will be described in detail below with reference to the accompanying drawings.

FIG. 1 is a vertical sectional view schematically showing an example of the constitution of a kneading machine and a cooling machine used in the toner manufacturing method of the present invention, and FIG. 2 is a perspective view of the vicinity of the extrusion port of FIG. Less than,
In FIG. 1, the left side is described as a "base end" and the right side is described as a "tip end".

[Raw Material] At least the toner of the present invention comprises
It is manufactured using a raw material 5 containing a resin (binder resin), a colorant, and a wax.

Examples of the resin (binder resin) include polystyrene, poly-α-methylstyrene, chloropolystyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-chloride. Vinyl copolymer, styrene-vinyl acetate copolymer, styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, styrene-acrylic acid ester-methacrylic acid ester copolymer Coalesced, styrene-α-
A styrene resin such as a methyl chloroacrylate copolymer, a styrene-acrylonitrile-acrylic acid ester copolymer, a styrene-vinyl methyl ether copolymer, or a homopolymer or copolymer containing styrene or a styrene substituent, a polyester resin. , Epoxy resin, urethane modified epoxy resin, silicone modified epoxy resin, vinyl chloride resin, rosin modified maleic acid resin, phenyl resin, polyethylene, polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer , Xylene resin, polyvinyl butyral resin, terpene resin, phenol resin,
Examples thereof include aliphatic or alicyclic hydrocarbon resins, and of these, one kind or a combination of two or more kinds can be used.

The content of the resin in the raw material 5 is not particularly limited, but is preferably 50 to 95 wt%,
More preferably, it is 80 to 94 wt%.

As the colorant, for example, a pigment, a dye or the like can be used. Examples of such pigments and dyes include carbon black, spirit black,
Lamp black (C.I. No. 77266), magnetite, titanium black, yellow lead, cadmium yellow,
Mineral Fast Yellow, Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Chrome Yellow, Benzidine Yellow, Quinoline Yellow, Tartrazine Lake, Red Mouth Lead, Molybdenum Orange, Permanent Orange GTR, Pyrazolone Orange, Benzidine Orange G, Cadmium Red, Permanent Red 4R, Watching Red Calcium Salt, Eosin Lake, Brilliant Carmine 3
B, manganese purple, fast violet B, methyl violet lake, navy blue, cobalt blue, alkali blue lake, Victoria blue lake, fast sky blue, indanthrene blue BC, ultramarine blue, aniline blue, phthalocyanine blue, chalco oil blue, chrome green , Chromium oxide, pigment green B, malachite green lake, phthalocyanine green, final yellow green G, rhodamine 6G, quinacridone, rose bengal (C.I. No. 4543).
2), C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Mordant Red 30, C.I.
I. Pigment Red 48: 1, C.I. I. Pigment Red 57: 1, C.I. I. Pigment Red 122, C.I.
I. Pigment Red 184, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I.
I. Mordant Blue 7, C.I. I. Pigment Blue 1
5: 1, C.I. I. Pigment Blue 15: 3, C.I. I.
Pigment Blue 5: 1, C.I. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Basic Green 6, C.I. I. Pigment Yellow 17, C.I.
I. Pigment Yellow 93, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 12, C.I. I.
Pigment Yellow 180, C.I. I. Pigment Yellow 162, Nigrosine Dye (C.I. No. 50415)
B), metal complex dyes, silica, aluminum oxide, magnetite, maghemite, various ferrites, cupric oxide, nickel oxide, zinc oxide, zirconium oxide, titanium oxide, metal oxides such as magnesium oxide and Fe, C
Examples thereof include magnetic materials containing magnetic metals such as o and Ni, and of these, one kind or a combination of two or more kinds can be used.

The content of the colorant in the raw material 5 is not particularly limited, but is preferably 1 to 10 wt%,
It is more preferably 2 to 7 wt%. If the content of the colorant is less than the lower limit, depending on the type of colorant,
It can be difficult to form a visible image of sufficient density. On the other hand, when the content of the colorant exceeds the upper limit,
There is a possibility that the fixing property and the charging property of the finally obtained toner may deteriorate.

As the wax (anti-offset agent),
Function to prevent and suppress the occurrence of offset phenomenon (mold release)
It may be any one having the following properties. For example, candelilla wax, carnauba wax, rice wax, plant wax such as cotton wax and wooden wax, animal wax such as beeswax and lanolin. , Wax waxes, mineral waxes such as montan wax, ozokerite, celsine, paraffin wax, micro wax, microcrystalline wax, petroleum waxes such as petrolatum, natural wax waxes, Fischer-Tropsch wax, polyethylene wax (polyethylene resin) ), Polypropylene wax (polypropylene resin), oxidized polyethylene wax, oxidized polypropylene wax, and other synthetic hydrocarbon wax,
Examples thereof include 12-hydroxystearic acid amide, stearic acid amide, phthalic anhydride imide, fatty acid amides such as chlorinated hydrocarbons, synthetic waxes and waxes such as esters, ketones and ethers. Further, as the wax, a crystalline polymer resin having a lower molecular weight may be used, and examples thereof include homopolymers or copolymers of polyacrylates such as poly-n-stearyl methacrylate and poly-n-lauryl methacrylate (for example, It is also possible to use a crystalline polymer having a long alkyl group in its side chain, such as a copolymer of n-stearyl acrylate-ethyl methacrylate). Among the above materials, carnauba wax, rice wax, polyethylene, polypropylene,
It is preferable to use an ester wax. As a result, the toner finally obtained can have an excellent balance of fixing characteristics and durability.

The content of wax in the raw material 5 is not particularly limited, but is preferably 2.0 wt% or more, more preferably 2.1 to 9.0 wt%,
More preferably, it is 2.4 to 5.5 wt%. If the wax content is less than 2.0 wt%, it may be difficult to sufficiently improve the offset resistance of the finally obtained toner.

The softening point of the wax is not particularly limited, but is preferably 50 to 180 ° C., and 60 to 160.
More preferably, it is ° C.

When the softening point of the wax is T _s [° C.] and the melting point of the resin is T _m [° C.], it is preferable that the relationship of T _s <T _m is satisfied, and (T _s +10) < It is more preferable to satisfy the relationship of T _m . By satisfying such a relationship, it becomes possible to fix the toner at a lower temperature and a higher speed.

In the raw material 5, the resin, colorant,
Ingredients other than wax may be included. Examples of such a component include magnetic powder, a charge control agent, and dispersed particles.

Examples of the magnetic powder include magnetite, maghemite, various ferrites, cupric oxide,
Metal oxides such as nickel oxide, zinc oxide, zirconium oxide, titanium oxide and magnesium oxide, Fe, Co,
An example is a magnetic material containing a magnetic metal such as Ni.

Examples of the charge control agent include benzoic acid metal salts, salicylic acid metal salts, alkylsalicylic acid metal salts, catechol metal salts, and metal-containing bisazo dyes.
Examples thereof include nigrosine dye, tetraphenylborate derivative, quaternary ammonium salt, alkylpyridinium salt, chlorinated polyester, nitrofunnic acid and the like.

Examples of the dispersant include metal soap,
Examples thereof include inorganic metal salts, organic metal salts, polyethylene glycol and the like.

Examples of the metal soaps include metal salts of tristearic acid (eg, aluminum salt), metal salts of distearic acid (eg, aluminum salt, barium salt, etc.), metal salts of stearic acid (eg, calcium salt, lead salt, etc.). Zinc salt etc.), linolenic acid metal salt (eg cobalt salt, manganese salt, lead salt, zinc salt etc.), octanoic acid metal salt (eg aluminum salt, calcium salt, cobalt salt etc.),
Oleic acid metal salt (eg calcium salt, cobalt salt etc.), palmitic acid metal salt (eg zinc salt etc.), naphthenic acid metal salt (eg calcium salt, cobalt salt, manganese salt, lead salt, zinc salt etc.) , Resinic acid metal salts (eg, calcium salt, cobalt salt, manganese lead salt, zinc salt, etc.) and the like.

Examples of the inorganic metal salt and the organic metal salt include, as a cationic component, IA of the periodic table.
Anions selected from the group consisting of halogens, carbonates, acetates, sulphates, borates, nitrates, and phosphates as anionic components, containing a cation of an element selected from the group consisting of Group IIIA, Group IIA, and Group IIIA metals. And the like.

In addition to the above materials, for example, zinc stearate, zinc oxide, cerium oxide or the like may be used as the additive.

[Kneading / Extrusion Step] The raw material 5 as described above is kneaded to obtain a kneaded material 7. The main purpose of such kneading is to sufficiently disperse the above-mentioned components in a sufficiently uniform manner and to sufficiently miniaturize the wax particles in the obtained kneaded product.

The operation itself of kneading the raw materials for toner production to produce a kneaded product has been carried out in the conventional production method. However, in the conventional manufacturing method, even if such kneading is sufficiently performed (even if the kneading time is sufficiently long and the kneading strength is sufficiently large), the wax in the toner particles finally obtained is obtained. In some cases, the particles could not be made sufficiently fine.

Therefore, the present inventor has proposed a method for producing a kneaded product,
Various studies were conducted on manufacturing conditions. As a result,
The raw material 5 is kneaded by using the kneading machine 1 having the extrusion port 3 on the side surface of the process section as shown in FIG. 2, and the obtained kneaded material 7 is extruded almost vertically to finely disperse the wax particles. It was found that the toner thus prepared can be stably provided. Hereinafter, the structure of the kneading machine 1, kneading of the raw material 5 using the kneading machine 1, and extrusion of the kneaded material 7 will be described in detail.

The kneading machine 1 has a process section 2 for kneading while conveying the raw material 5, and a feeder 4 for supplying the raw material 5 into the process section 2.

The raw material 5 charged in the feeder 4 is preferably a mixture of the above-mentioned components in advance.

The process section 2 includes a barrel 21 and a barrel 2
1 has screws 22 and 23 inserted therein.

In the process section 2, the screws 22 and 23 are
By rotating around the rotating shafts 220 and 230 in the directions indicated by a and b in the figure, respectively.
A shearing force is applied to the raw material 5 supplied from the above to obtain a kneaded material 7 in which the above components are sufficiently uniformly dispersed. That is,
By the kneading in the process section 2, a kneaded material 7 in which wax particles are sufficiently finely dispersed is obtained.

The raw material temperature at the time of kneading varies depending on the composition of the raw material 5 and the like, but is preferably 70 to 250 ° C., and 80
More preferably, the temperature is 160 ° C.

In addition, the raw material 5 supplied from the feeder 4
By rotating the screws 22 and 23 in the directions indicated by a and b in the drawing, respectively, and
Is conveyed in the direction (direction indicated by c in the figure). That is, the raw material 5 is kneaded while the screws 22, 23
Is conveyed in the direction of the rotation axis of the.

A spiral groove 221 is formed in the screw 22. Similarly, on the screw 23, a groove having the same rotation direction as the groove 221 is formed at a corresponding position (not shown). By providing such grooves in the screws 22 and 23, the raw material 5 can be kneaded more efficiently. Further, by providing such a groove, the raw material 5 and the kneaded material 7 can be more efficiently conveyed in the direction indicated by c in the figure.

Further, the screw 22 is formed with a groove 222 having a spiral rotation direction different from that of the groove 221 on the tip side thereof. Similarly, in the screw 23, a groove having the same rotation direction as the groove 222 is formed at a corresponding position (not shown). By forming such grooves in the screws 22 and 23, the screws 22 and 2
Even when a part of the kneaded material 7 conveyed with the rotation of 3 is extruded to the tip side from the extrusion port 3, the kneaded material is efficiently conveyed in the direction indicated by d in the figure. be able to. As a result, the kneaded material 7 can be efficiently extruded from the extrusion port 3.

In the configuration shown in the drawing, the rotation direction reversal portion 223 (the boundary between the groove 221 and the groove 222) in which the spiral direction of the groove provided in the screw 22 is reversed is almost directly above the extrusion port 3. In this way, when the rotation direction reversal section 223 is near the extrusion port 3, the extrusion efficiency of the kneaded material 7 from the extrusion port 3 in the extrusion step described later becomes particularly excellent.

The kneaded material 7 obtained by kneading the raw material 5 is extruded from the extrusion port 3.

As described above, the present invention is characterized in that the extrusion port 3 is provided on the side surface of the process section 2, so that the wax particles in the finally obtained toner particles can be sufficiently dispersed. Can be miniaturized. This is considered to be due to the following reasons.

Conventionally, the kneading machine used for producing the toner is equipped with a head for adjusting the cross-sectional shape of the kneaded product to be extruded at the end of the process section, and the kneading is performed from the extrusion port formed in the head. It had a structure for discharging an object. When a kneader with such a structure is used, the kneaded material in the barrel passes through the head before being discharged to the outside of the kneader, but in the head, the kneaded material is almost sheared. No force or much less shear than the process area. Therefore, reaggregation of the wax particles in the kneaded material progresses in the head, and the particle diameter becomes coarse.

On the other hand, in the present invention, the kneaded material 7 is directly discharged from the process section 2 (without passing through a head or the like) to the outside of the kneading machine 1, and the discharged kneaded material 7 is discharged. The cooling step described later can be promptly provided. As a result, reaggregation of the wax particles in the kneaded material 7 can be effectively prevented or suppressed, and the wax particles in the finally obtained toner particles can be sufficiently miniaturized. Therefore, the finally obtained toner is unlikely to cause wax exudation, etc., and as a result, has excellent durability,
The so-called fog phenomenon is less likely to occur.

The kneaded material 7 is fed from the extrusion port 3 to the kneading machine 1
It is pushed out almost vertically. In this way, by extruding the kneaded material 7 in a substantially vertical direction, the kneaded material 7
Can be provided to the cooling step described later more quickly. As a result, the reaggregation of the wax particles in the kneaded material 7 can be prevented and suppressed more effectively,
The wax particle size in the finally obtained toner particles is also particularly small.

In the illustrated construction, the extrusion port 3 is provided below. Thereby, the kneaded material 7 can be discharged to the outside of the kneading machine 1 more efficiently. As a result, kneaded product 7
The reaggregation of the wax particles therein can be more effectively prevented and suppressed, and the wax particle diameter in the finally obtained toner particles also becomes particularly small.

The extrusion port 3 has a cross-sectional area increasing portion 31 whose cross-sectional area increases along the direction in which the kneaded material 7 is extruded.
have. Thereby, the kneaded material 7 can be discharged from the extrusion port 3 more efficiently. As a result, the reaggregation of the wax particles in the kneaded material 7 can be prevented and suppressed more effectively.

In the illustrated construction, the cross-sectional area of the extrusion port 3 is
Although it increases intermittently, it may increase continuously.

[Cooling Step] The kneaded material 7 extruded from the extrusion port 3 is cooled by the cooler 6.

The cooler 6 comprises rolls 61, 62, 63, 6
4 and belts 65 and 66.

The belt 65 is wound around the roll 61 and the roll 62. Similarly, the belt 66 is a roll 6
3 and a roll 64.

The rolls 61, 62, 63 and 64 respectively rotate about the rotation shafts 611, 621, 631 and 641 in the directions indicated by e, f, g and h in the figure. Thereby, the kneaded material 7 extruded from the extrusion port 3 of the kneading machine 1
Is introduced between the belt 65 and the belt 66. Belt 6
The kneaded material 7 introduced between the 5-belt 66 is cooled while being formed into a plate having a substantially uniform thickness. The cooled kneaded material 7 is discharged from the discharge portion 67. The belts 65 and 66 are, for example, water-cooled, air-cooled, or the like.
It is cooled. When such a belt type cooling machine is used as the cooling machine, the contact time between the kneaded product extruded from the kneading machine and the cooling body (belt) can be lengthened, and the cooling efficiency of the kneaded product is particularly excellent. It can be

The temperature of the kneaded material 7 in the vicinity of the extrusion port 3 is T
₁ [° C.], the temperature of the kneaded material 7 near the discharge part 67 (the temperature of the kneaded material 7 immediately after the completion of the cooling step) is T
₂ [° C.], when the time required from the extrusion of the kneaded material 7 from the extrusion port 3 to the completion of the cooling step is t [seconds], (T ₁ −T ₂ ) / t ≧ 5 [° C./second ], It is preferable that (T ₁ −T ₂ ) / t ≧ 10 [° C./sec]
It is more preferable to satisfy the relationship of. By satisfying such a relationship, the wax particles in the kneaded material 7 after cooling can be further refined. As a result, the wax particles in the finally obtained toner particles are also sufficiently miniaturized. As a result, the toner is less likely to cause wax bleeding, and has excellent durability,
The so-called fog phenomenon is less likely to occur.

The time t from the extrusion of the kneaded material 7 through the extrusion port 3 to the completion of the cooling step is 15
It is preferably seconds or less, and more preferably 10 seconds or less. If t is 15 seconds or more, it may be difficult to sufficiently miniaturize the wax particles in the kneaded material 7.

The average particle size of the wax in the kneaded material 7 thus cooled is not particularly limited, but 1.
It is preferably 5 μm or less, and more preferably 1.2 μm or less. When the average particle size of the wax exceeds 1.5 μm, it may be difficult to sufficiently reduce the size of the wax particles in the finally obtained toner.

[Crushing Step] The toner of the present invention can be obtained by crushing the kneaded material 7 which has undergone the cooling step as described above.

The pulverizing method is not particularly limited, and various pulverizing devices such as a ball mill, a vibration mill, a jet mill, a pin mill and a crushing device can be used.

The pulverizing process may be performed in plural times (for example, two stages of a coarse pulverizing process and a fine pulverizing process).

The average particle size of the toner obtained by pulverization is
The thickness is preferably 4 to 12 μm, more preferably 5.5 to 10 μm. When the average particle diameter of the toner is less than the lower limit value, it becomes difficult to uniformly charge the toner, and in a printed matter using the toner, image quality is likely to be deteriorated due to fog or the like. On the other hand, when the average particle diameter of the toner exceeds the upper limit value, the resolution of the output image tends to decrease.

The average particle diameter of the wax in the toner thus obtained is preferably 1.5 μm or less,
It is more preferably 1.2 μm or less. When the average particle diameter of the wax exceeds 1.5 μm, the wax is likely to be exuded, and sufficient durability may not be obtained.

After the above-mentioned crushing step, if necessary, classification treatment, spheroidization treatment, external addition treatment and the like may be carried out.

For the classification treatment, for example, a sieve, an elbow shot utilizing the Coanda effect, an ATP using a rotor, TSP, TTSP, an air classifier such as a centrifugal separator DS separator, or the like can be used. it can.

Examples of the sphering method include a suffusing system using hot air and a hybridization system using mechanical impact force.

As the external additive, for example, silica, aluminum oxide, titanium oxide, strontium titanate, cerium oxide, magnesium oxide, chromium oxide, titania, zinc oxide, metal oxides such as alumina and magnetite, and silicon nitride can be used. Fine particles composed of an inorganic material such as a nitride, a carbide such as silicon carbide, calcium sulfate, calcium carbonate, a metal salt such as an aliphatic metal salt, an acrylic resin, a fluororesin, a polystyrene resin, a polyester resin, an aliphatic metal salt, etc. Examples thereof include fine particles composed of the organic material and fine particles composed of a composite material thereof.

As the external additive, the surface of the fine particles as described above is surface-treated with HMDS, a silane coupling agent, a titanate coupling agent, a fluorine-containing silane coupling agent, a silicone oil, or the like. You may use what was done.

The toner thus obtained is preferably used for a color toner which is required to have a sharp melt property or a printer having an oilless fixing device. Such a toner is required to have a relatively high wax content. As a result, such a toner is likely to be adversely affected by the above-described coarsening of the wax particles, and the effect of the present invention becomes more prominent.

The toner manufacturing method and toner of the present invention have been described above based on the preferred embodiments.
The present invention is not limited to this.

For example, in the above-described embodiment, the extrusion port 3
The shape was circular, but the shape is not limited to this. For example, the shape may be a polygon such as a quadrangle or an ellipse.

In the configuration shown in the figure, a kneading machine in which the tip of the process section 2 is opened has been described. For example, as a kneading machine, a kneader is provided at the tip side of the process section.
A screw bearing may be provided so that the front end side of the process section is closed.

In the above-described embodiment, the screw 22 having the grooves 221 and 222 in which the spiral rotation directions are different from each other has been described. However, the screw has a groove in which the spiral rotation direction is one direction. It may be formed or may not be formed with a groove.

Further, in the above-described embodiment, the structure using the screw 22 in which the grooves 221 and 222 having different spiral rotation directions are in contact with each other has been described, but the groove 221 and the groove 222 are different from each other. There may be a portion in which a groove is not formed.

In the above-described embodiment, the kneading machine 2 is used.
Although the configuration in which the screws of the book rotate in the same direction has been described, they may rotate in the opposite directions. In this case, it is preferable that the rotation directions of the grooves formed in the screw are also different from each other.

Further, in the above-mentioned embodiment, the raw material charging port is one, but it may be two or more.

Further, although the kneading machine having two screws in the illustrated structure has been described, the number of screws may be one or three or more.

Further, in the above-described embodiment, the structure using the belt type cooling device has been described.
For example, a roll type (cooling roll type) cooler may be used. Further, the cooling of the kneaded material extruded from the extrusion port of the kneading machine is not limited to the one using the cooling machine as described above, and may be, for example, air cooling or the like.

[0098]

EXAMPLES [Manufacture of Toner] A toner was manufactured as follows.

Example 1 First, as a resin (binder resin), an unsaturated polyester resin (T _m = 130) was used.
C): 100 parts by weight, copper phthalocyanine pigment as a colorant: 5 parts by weight, zinc salicylate complex as a charge control agent:
2 parts by weight, as a wax, kaunauba wax (T _s =
76 ° C.): 4 parts by weight were prepared.

Each of these components was mixed using a Henschel mixer to obtain a raw material for toner production.

Next, this raw material (mixture) was prepared as shown in FIGS.
Melt kneading was carried out using a kneader as shown in.

The temperature in the barrel during kneading is about 120.
It was ℃. The kneaded product extruded from the extrusion port of the kneader was cooled using a cooler as shown in FIG.

Temperature of the kneaded material near the extrusion port of the kneader
T₁Is 133 ° C, and the kneaded material near the discharge part of the cooler
Temperature T_TwoWas 66 ° C. Also, the kneaded product is
Time required to move from the extrusion port to the discharge part of the cooler
(The cooling process is completed after the kneaded material is extruded from the extrusion port.
It took 4 seconds. In addition, T
₁, T_TwoIs measured using an infrared radiation thermometer
It was In addition, the wax particles in the kneaded product after cooling are flat.
The average particle size was 0.67 μm.

The average particle size of the wax particles in the kneaded product was measured as follows. First, the kneaded product after cooling was sliced into about 0.1 μm with a microtome. The kneaded material thus sliced was observed with a transmission electron microscope (TEM) at a magnification of 5000 times. Wax particles in a constant visual field (40 μm × 40 μm) were observed, and the average particle size of the wax was calculated by an image analyzer.

The kneaded product cooled as described above was roughly pulverized (average particle diameter: 1 to 2 mm), and then finely pulverized.
A hammer mill was used for coarse pulverization of the kneaded product, and a jet mill was used for fine pulverization.

The pulverized product thus obtained was classified by an airflow distributor to obtain an average particle size of about 8 μm.

Then, 1.2 parts by weight of silica was mixed with 100 parts by weight of the classified pulverized product in a Henschel mixer to obtain a toner. The average particle diameter of the finally obtained toner was 8.04 μm.

Example 2 A styrene-acrylic copolymer resin (T _m = 145 ° C.) as a resin (binder resin),
Polyethylene wax as a wax (T _s = 124
A toner was manufactured in the same manner as in Example 1 except that (.degree. C.) was used.

Example 3 A toner was manufactured in the same manner as in Example 1 except that rice wax (T _s = 68 ° C.) was used as the wax. The temperature in the barrel during kneading was 135 ° C.

Example 4 A toner was manufactured in the same manner as in Example 1 except that the amount of the wax used for manufacturing the raw material was changed to 2 parts by weight.

(Examples 5 to 10) T ₁ [° C.], T ₂ [° C.], and t [sec] are values shown in Table 1 by changing the rotational speed of the screw and the rotational speed of the roll of the cooler. A toner was manufactured in the same manner as in Example 1 except for the above.

(Comparative Example 1) As a kneading machine, a commercially available continuous twin screw extruder (TEM41, manufactured by Toshiba Machine Co., Ltd.)
A toner was manufactured in the same manner as in Example 1 except that was used. This kneading machine is of a type in which a head is mounted on the front end side of the process section, and a kneaded product is extruded in a substantially horizontal direction from an extrusion port of the head.

Comparative Examples 2 to 7 T ₁ [° C.], T ₂ [° C.], and t [sec] are shown in Table 1 by changing the rotation speed of the screw of the kneader and the rotation speed of the roll of the cooler. A toner was manufactured in the same manner as in Comparative Example 1 except that the values shown in Table 1 were used.

[0114]

[Table 1]

[Evaluation] With respect to each of the toners obtained as described above, the average particle diameter of the wax particles dispersed in the toner, the durability, and the occurrence of fog were evaluated.

<Average Particle Diameter of Wax Particles Dispersed in Toner> The average particle diameter of the wax particles was evaluated as follows.

First, 10 toner particles were taken out from each of the toners manufactured in each of the examples and the comparative examples. Each of these toner particles was sliced to a size of about 0.1 μm with a microtome. The toner particles thus sliced were observed with a transmission electron microscope (TEM) at a magnification of 5000 times. Wax particles in a constant visual field (40 μm × 40 μm) were observed, and the average particle size of the wax particles was calculated by an image analyzer. The results obtained by such a method were evaluated according to the following four-step criteria.

[0118] A: The average particle size is less than 1.0 μm. ◯: The average particle size is 1.0 μm or more and less than 1.5 μm. Δ: Average particle size is 1.5 μm or more and 2.0 μm or less. X: The average particle size exceeds 2.0 μm.

<Evaluation of Toner Durability> The toner obtained in each of the examples and each of the comparative examples was applied to a commercially available laser printer (Seiko Epson LP-3000C).
Each was applied and 5000 sheets were run. 490
For the 1st to 5000th printed matter, these images
The evaluation was performed according to the following four-step criteria.

[0120] ⊚: No streak or disorder is observed in the image. ◯: Streaks and irregularities are hardly recognized in the image. B: Some streaks and irregularities are observed in the image. X: Streaks and irregularities are clearly observed in the image.

<Evaluation of Fog> The toner obtained in each of the examples and each of the comparative examples was applied to a commercially available laser printer (LP-3000C manufactured by Seiko Epson Corp.), and 5,000 sheets were run. 4901-
For the 5000th printed material, these images were evaluated according to the following four-step criteria.

[0122] ⊚: Fog is not observed at all. ○: Fog is hardly observed. Δ: Some fog was observed. X: Fog is clearly recognized. The results are summarized in Table 2.

[0123]

[Table 2]

As is clear from Table 2, the toner of the present invention was one in which wax particles were finely dispersed. Further, the toner of the present invention is excellent in durability, and generation of fog was not recognized in the printed matter obtained by using them.

On the other hand, in the toner of the comparative example, the wax particles were coarse. Further, the toner of the comparative example is
The durability was inferior, and fog was remarkably observed in the printed matter obtained by using them.

Further, as a colorant, Pigment Red 57: 1, C.I. I. Toners were produced in the same manner as in each of the examples and each of the comparative examples except that Pigment Yellow 93 and carbon black were used, and the same evaluations as described above were performed for each of these toners. As a result, the same results as those in each of the examples and each of the comparative examples were obtained.

[0127]

As described above, according to the present invention, it is possible to provide a toner in which wax particles are finely dispersed.

Such an effect can be further enhanced by adjusting the time required for the cooling step to be completed after the kneaded product is extruded from the extrusion port.

[Brief description of drawings]

FIG. 1 is a kneading machine used in the method for producing a toner of the present invention,
It is a longitudinal section showing an example of composition of a cooler typically.

FIG. 2 is a perspective view of the vicinity of the extrusion port of FIG.

[Explanation of symbols]

1 ... Kneading machine 2 ... Process section 21 ... Barrel 2
2,23 ... Screw 220,230 ... Rotating shaft
221 ... Groove portion 222 ... Groove portion 223 ... Rotation direction reversing portion 3 ... Extrusion port 31 ... Cross-sectional area increasing portion 4 ...
... Feeder 5 ... Raw material 6 ... Cooling machine 61, 62, 63, 64 ...
… Rolls 611, 621, 631, 641 …… Rotary shafts 65, 66 …… Belt 67 …… Discharging section 7 …… Kneaded product

Claims (18)

[Claims] 1. Production of a toner having at least a step of kneading a raw material containing a resin, a colorant, and a wax by using a kneader to obtain a kneaded product, and a cooling step of cooling the kneaded product. In the method, the kneading machine has a process section for kneading while conveying the raw material, the side surface of the process section is provided with an extrusion port through which the kneaded product is extruded, and from the extrusion port, A method for producing a toner, which comprises extruding a kneaded product. 2. The method for producing a toner according to claim 1, wherein the kneaded product is extruded in a direction substantially perpendicular to a direction in which the raw material is conveyed in the process section. 3. The method for producing a toner according to claim 1, wherein the extrusion port is provided substantially below the process section, and the kneaded product is extruded substantially vertically downward. 4. The method for producing a toner according to claim 1, wherein the process section has one or more screws, and conveys the raw material in a rotation axis direction of the screws. 5. The method for producing a toner according to claim 4, wherein an extrusion direction of the kneaded material extruded from the extrusion port and a rotation axis direction of the screw are substantially perpendicular to each other. 6. The screw according to claim 4, wherein a spiral groove is formed on the outer periphery of the screw, and the screw has a position in which the spiral rotation direction of the groove is different from the axial direction of the screw. Manufacturing method of toner. 7. The method for producing a toner according to claim 6, wherein the kneaded product is extruded from the extrusion port provided in the vicinity of a portion where the rotation direction of the spiral of the groove with respect to the axial direction of the screw is reversed. 8. The extrusion port according to claim 1, wherein the extrusion port has a portion whose cross-sectional area increases continuously or intermittently along the direction in which the kneaded product is extruded. Toner manufacturing method. 9. The method for producing a toner according to claim 1, wherein the content of the wax in the raw material is 2.0 wt% or more. 10. The method for producing a toner according to claim 1, wherein an average particle diameter of the wax in the kneaded product after the cooling step is 1.5 μm or less. 11. The softening point of the wax is T_s[℃],
If the melting point of the resin is T _mWhen [° C], T_s<T_mof
11. The relationship according to claim 1, which satisfies the relationship.
Toner manufacturing method. 12. The temperature of the kneaded product near the extrusion port is T ₁ [° C.], the temperature of the kneaded product immediately after the completion of the cooling step is T ₂ [° C.], and the kneaded product is extruded from the extrusion port. When the time required to complete the cooling step after the completion of the cooling is t [seconds], (T ₁ −T ₂ ) / t ≧
The method for producing a toner according to claim 1, wherein the relationship of 5 [° C./second] is satisfied. 13. The time t required from the extrusion of the kneaded product from the extrusion port to the completion of the cooling step.
Is 15 seconds or less, the method for producing a toner according to claim 1. 14. The method for producing a toner according to claim 1, further comprising a step of pulverizing the kneaded product. 15. The method for producing a toner according to claim 1, wherein the toner is a color toner. 16. A toner produced by the method according to any one of claims 1 to 15. 17. The toner according to claim 16, which has an average particle diameter of 4 to 12 μm. 18. The average particle diameter of the wax in the toner is 1.5 μm or less.
The toner according to.