JPH05289395A - Electrophotographic toner and its production - Google Patents

Abstract

PURPOSE:To produce a toner excellent in electrostatic charge characteristics, electrostatic charge stability (moisture resistance and environmental resistance) and metallic tone. CONSTITUTION:A domain resin 2, a colorant and a metallic material 4 are melted and kneaded. The resulting kneaded material, a matrix resin 1 having low miscibility with the domain resin 2 and an auxiliary dispersant 3 having miscibility with both the resins 1, 2 and a higher Izod impact value than that of the matrix resin 1 are melted and kneaded to obtain a colored compsn. and the objective toner is produced by pulverizing and classifying the colored compsn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner and a method for producing the same, and more particularly, an electrophotographic toner in which a domain resin having a colorant and a metallic material dispersed therein is dispersed in a matrix resin and a method for producing the same. Regarding

[0002]

2. Description of the Related Art In the field of electrophotography today, various color copies are possible in addition to conventional black and white copies. A metallic tone is also desired as a color for such color copying. In the toner used for forming a metallic copy, a metallic material for producing a metallic tone is added to the conventional ordinary colorant. Then, generally, a colorant and a metallic material are melt-kneaded in a matrix resin as a binder, the kneaded product is crushed, and the crushed product obtained is classified to have a predetermined particle size distribution. There is. However, in order to obtain a uniform and sufficiently satisfactory metallic color tone, it is necessary to uniformly disperse the colorant and a large amount of the metallic material in the matrix resin. There is a limit, and it is difficult to obtain such a metallic color.

Moreover, the toner obtained by the pulverization method has the colorant and the metallic material exposed unevenly on the surface thereof. The colorant is inferior in moisture resistance and environment resistance, and therefore causes problems in uniformity of charge amount of each toner and storage / environmental stability. In addition, the chargeability becomes unstable due to the detachment of the colorant and the adhesion to the carrier surface, resulting in toner fog,
This may cause toner spillage and toner scattering. In particular, when a metallic material, especially a metallic metallic material is exposed on the surface, the metallic material greatly reduces the charge amount, and toner fog, toner spill, toner scattering and the like become more remarkable.

In order to prevent the adverse effects of the exposure of the colorant and the metallic material to the toner surface, it is considered to apply a micro-dispersion technique for enclosing the colorant and the like in a specific phase in the toner (for example, a special method). Kai 627-1775
3 gazette). In such a micro-dispersion technique, the exposure of the colorant or the like can be suppressed until the kneading stage, but the exposure of the surface of the colorant or the like remains a problem after pulverization.
Furthermore, in the method of pulverizing a kneaded product for toner to produce a toner, over-pulverized toner is likely to be generated, the width of the particle size distribution of the pulverized toner is considerably widened, and when the toner having a specific particle size range is classified, The yield is extremely low. In particular, in order to improve the image quality of electrophotographic copied images, a toner having a small particle size and a narrow particle size distribution width is required.
The conventional toner has a problem that an excessively pulverized product is apt to be generated and a classification yield is remarkably poor.

As a method for efficiently producing a toner having a uniform particle size distribution by preventing the surface exposure of a colorant or the like, application of a method of granulating in a solution such as a suspension polymerization method or a spray drying method is considered. However, the obtained particles have extremely high sphericity, and blade cleaning, which is a conventional general-purpose cleaning method, has a problem such as toner unwiping, which is complicated when trying to avoid this. It is necessary to adopt a cleaning method. Further, since the toner production method by the suspension polymerization method is a new method, it is not possible to use the existing equipment of the existing kneading and pulverization method, and there is a problem that new equipment investment is required.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances and provides a uniform metallic tone, suppresses the surface exposure of the colorant and the metallic material, and improves the charging characteristics and the charging stability. It is an object of the present invention to provide an irregular-shaped electrophotographic toner having excellent properties (moisture resistance, printing durability, environment resistance, storage resistance). A further object of the present invention is to provide a toner manufacturing method which is a toner in which a colorant and a metallic material are sufficiently uniformly dispersed, has a small amount of free powder when pulverized, and can be efficiently manufactured.

[0007]

The present invention is directed to a domain resin composition containing a colorant and a metallic material in a domain resin, a matrix resin composition having low miscibility with the domain resin, and both the domain resin and the matrix resin. For electrophotography, which contains at least a dispersion aid which is miscible with the resin and has an Izod impact value higher than that of the matrix resin, and the domain resin composition is dispersed in the matrix resin composition through the dispersion aid. Regarding toner.

The present invention further includes (a) a step of obtaining a kneaded product obtained by melt-kneading a domain resin, a colorant and a metallic material, and (b) a kneaded product and a domain resin obtained in the step (a). Low miscibility matrix resin, and a step of obtaining a colored composition by melt-kneading a dispersion aid having miscibility with both the domain resin and the matrix resin and having an Izod impact value higher than that of the matrix resin,
(C) A method for producing an electrophotographic toner, which comprises a step of pulverizing and classifying the kneaded product obtained in the step (b).

The constitution of the electrophotographic toner of the present invention is conceptually understood as shown in FIG. That is, the toner of the present invention includes at least the matrix resin (1), the domain resin (2) dispersed in the matrix resin phase, the coloring agent and the metallic material (4) present in the domain resin phase, and the domain resin phase. And a dispersion aid (3) present between the matrix resin phase. The dispersion aid phase covers at least part of the domain resin phase. Resins having a certain difference in impact resistance are used as the dispersion aid and the matrix resin, and by doing so, the domain resin is effectively prevented from being destroyed in the pulverization process during toner production. .. As a result, the colorant and the metallic material (4) are enclosed in the domain resin and are not exposed on the surface of the toner particles, so that the charging can be stabilized. Further, the presence of such a dispersion aid phase prevents excessive pulverization, resulting in extremely high production efficiency.
Further, with the constitution of the present invention, since a large amount of metallic material can be contained, it is possible to form a sufficiently satisfactory metallic-like copied image having excellent uniformity.

Examples of the matrix resin for the electrophotographic toner of the present invention include ethylene, propylene and butene-
1, homopolymers of α-olefins (including ethylene) such as pentene-1, 4-methylpentene-1, and hexene-1, or copolymers thereof, a majority weight of these α-olefins and other unsaturated compounds Block, random or graft copolymers, olefin polymers such as modified polymers obtained by subjecting these homopolymers or copolymers to halogenation, sulfonation, oxidation, acrylonitrile, styrene copolymers (AS resin) , Polycarbonate, thermoplastic polyester, polyamide, polystyrene, styrene-butadiene-styrene-block copolymer, thermoplastic polymer such as polyacrylonitrile, polymethylmethacrylate, and rubber.

Other unsaturated compounds which can be copolymerized with α-olefin in the above olefin polymers include vinyl esters such as vinyl acetate, vinyl silanes such as vinyl trimethoxysilane and vinyl triacetoxy silane, and the above-mentioned examples. And the ethylenically unsaturated monomer other than the α-olefin.

As the thermoplastic polymer used in the present invention, polyester and polystyrene are preferable as the matrix phase.

The polyester preferably used in the present invention is appropriately selected from those generally obtained by polycondensation of a polybasic acid and a polyhydric alcohol.

Here, as the polybasic acid, terephthalic acid,
Aromatic carboxylic acids such as isophthalic acid and trimellitic acid, adipic acid, hexahydroterephthalic acid, succinic acid, n-
Dodecenyl succinic acid, iso-dodecenyl succinic acid, n-
Examples thereof include aliphatic carboxylic acids such as dodecyl succinic acid, n-octyl succinic acid, iso-octyl succinic acid and n-butyl succinic acid, unsaturated carboxylic acids such as maleic acid and fumaric acid, and their anhydrides. As the polyhydric alcohol component, ethylene glycol, propylene glycol, 1,4-butanediol, hexamethylene glycol, neopentyl glycol, 2,2,4,4-tetramethylene glycol, glycerin, trimethylolpropane, bisphenol A, Hydrogenated bisphenol A, sorbitol or etherified hydroxyl compounds thereof, such as polyoxyethylene (10) sorbitol, polyoxypropylene (5) glycerin, polyoxyethylene (4) pentaerythritol, polyoxypropylene
Examples include (2,2) -2,2-bis (4-hydroxyphenyl) propane and polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane.

The polyester in which the effects of the present invention are remarkably exhibited is solvent-soluble. Amorphous or low-crystalline ones, especially those having a crystallinity of less than 5% by X-ray analysis, are effective. 40-150 for softening point
C., especially 60 to 150.degree. C., and number average molecular weight of 500 to 30,000, especially 1000 to 2000.
A value of 0 is highly effective.

The polystyrene preferably used in the present invention is polystyrene or a copolymerization monomer with styrene, for example, unsaturated carboxylic acid such as acrylic acid and methacrylic acid, methyl acrylate, ethyl acrylate and methyl methacrylate, n-methacrylic acid. In addition to unsaturated carboxylic acid esters such as butyl, dibutyl fumarate, and dioctyl fumarate, maleic anhydride, acid anhydrides such as itaconic anhydride, so-called unsaturated carboxylic acids or derivatives thereof, etc. within a range not exceeding a majority. The thing copolymerized by is used.
Among them, the glass transition temperature is 30 to 105 ° C, the number average molecular weight is 1000 to 150,000, and particularly 2000 to 1000.
No. 00 has a great effect.

As the polystyrene used in the present invention, a solvent-soluble one is particularly preferable. These matrix resins need only be present in an amount sufficient to substantially cover the dispersed domain resin component, and thus can be used in a wide range for toner. Therefore, it is generally preferable to use 20 to 99% by weight, more preferably 30 to 95% by weight, based on the toner resin. When the amount is less than the above range, the matrix resin and the domain resin undergo phase inversion, the colorant-containing resin is exposed on the crushed surface, resulting in poor charging, and over-milling is likely to occur, resulting in a wide particle size distribution and poor manufacturing efficiency. On the other hand, if the amount exceeds the above range, the colorant may be poorly dispersed in the matrix resin.

As the domain resin, the same resin as the above-mentioned matrix resin can be used, but the compatibility is changed by changing the comonomer to be copolymerized, and those which are not uniformly mixed with each other are used. By doing so, a domain resin can be dispersed in the matrix resin.

In the electrophotographic toner of the present invention, the colorant is dispersed and held in the domain resin, and the domain resin is dispersed in the matrix resin. Dispersing and holding the colorant in the domain resin has the effect of preventing the colorant from being exposed on the toner surface and making the chargeability of the toner surface uniform. Further, when the domain resin holding the colorant dispersed therein is uniformly dispersed in the matrix resin, bleeding and color bleeding do not occur.

That is, in the toner composition of the present invention, the matrix resin and the domain resin are resins which are not uniformly mixed with each other, and one having a greater affinity for the colorant to be used acts as the domain resin.

The dispersion aid used in the electrophotographic toner of the present invention is a copolymer containing a domain resin component and a matrix resin component. A resin obtained by graft-copolymerizing a monomer containing one of the domain resin and the matrix resin with a monomer forming the other resin is preferable.

The dispersion aid used in the present invention acts to finely disperse the domain resin in the matrix resin, and if it is 1% by weight in the toner composition, the dispersed phase becomes sufficiently fine and uniform. It is preferably used in an amount of 3% by weight or more. The dispersion aid has an Izod impact value of 0.1 kgf · cm / cm or more, preferably 0.2 kgf ·
cm / cm or more, more preferably 0.4 kgf · cm / cm or more is used. By using such a resin, breakage of the domain resin can be prevented by preferentially causing breakage in the matrix resin phase in the pulverizing step. Therefore, since the colorant remains trapped in the domain resin phase, it is possible to prevent the adverse effect of the exposure of the colorant on the toner surface. When the Izod impact value is smaller than the above range, the domain resin is likely to be stressed, and thus easily broken. When the domain resin phase is destroyed, the adverse effect due to the exposure of the colorant is likely to occur. In addition, over-pulverization is likely to occur and the particle size distribution is widened, resulting in a marked deterioration in manufacturing efficiency.

In the present invention, the Izod impact value is a Mini-max Izot impact tester (Model CS-183; Instrume).
(manufactured by NT Inc.). At the time of measurement, a test piece of 30 × 12 × 2.0 [mm] was produced by press molding (conditions 130 ° C., 60 to 70 kg / cm ² ), and this test piece was provided to the above tester.

Specific examples of the dispersion aid include a method in which the styrene polymer and the vinyl monomer are graft-reacted, a method in which the polymer is dissolved in a solvent and the vinyl monomer is added to the solution to cause a reaction. To dissolve and react the polymer in, to suspend the polymer particles in water, add vinyl monomer to this to impregnate the polymer particles, then react, to dissolve the polymer in vinyl monomer There are a method of reacting the above in a state of being suspended as droplets in water, a method of reacting with a vinyl monomer in a molten state of a polymer, a radiation grafting method and the like. Among them, the preferable method is the above method or. The polymer obtained by the above method contains a matrix resin and a domain resin at the same time, and can be used without separately adding the matrix resin or the domain resin.

In this reaction, a polymerization initiator is usually used. As the polymerization initiator, those generally used for radical polymerization can be used, but the decomposition temperature is 45 to 110 ° C., especially 50 to 105, in view of the temperature of the polymerization reaction.
It is preferable to select from those in the range of ° C. The decomposition temperature as used herein means that the polymerization initiator is added to 0.1 liter in 1 liter of benzene.
It means the temperature at which the decomposition rate of the radical generator reaches 50% when it is allowed to stand for 10 hours after adding a mole.

Specific examples of such an initiator include 2,4-dichlorobenzoyl peroxide (54 ° C.), t
ert-butyl peroxypivalate (56 ° C), O-methylbenzoyl peroxide (57 ° C), bis-3,5,5-
Trimethylhexanoyl peroxide (60 ℃), octanoyl peroxide (61 ℃), lauroyl peroxide
(62 ° C), benzoyl peroxide (74 ° C), tert-butylperoxy-2-ethylhexanoate (74 ° C),
1,1-bis (tert-butylperoxy) -3,5,5-trimethylcyclohexane (91 ° C), cyclohexanone peroxide (97 ° C), 2,5-dimethyl-2,5-dibenzoylperoxyhexane (100 ° C) , Tert-butyl peroxybenzoate (104 ° C.), di-tert-butyl-
Diperoxyphthalate (105 ° C), methyl ethyl ketone peroxide (109 ° C), dicumyl peroxide (1
17 ° C.), and organic peroxides such as dicumyl-tert-butyl peroxide (temperatures in parentheses indicate decomposition temperatures). These can be used together.

The amount of the polymerization initiator used is 0.05 to 30% by weight, preferably 0.1 to 10% by weight based on the vinyl monomer.
It is in the range of% by weight.

In the present invention, the dispersion aid comprises a matrix resin (for example polyester) and a monomer (for example styrene) which can give a domain resin "in situ".
u) ”can also be obtained by graft copolymerization.

As the colorant used in the electrophotographic toner of the present invention, carbon black, rhodamine B and the like are basic dyes, acid dyes, fluorescent dyes, azo dyes, anthraquinone dyes, azine dyes, nigrosine dyes, There are metal complex compound type dyes, red iron oxide, titanium oxide, cadmium yellow, cadmium red, basic dye lake, phthalocyanine type pigments and the like. The amount of these colorants added is
Generally, it is used in an amount of 0.05 to 50% by weight, more preferably 0.1 to 20% by weight, based on the toner resin. Since it is necessary to disperse and fill substantially the entire amount of the colorant and the domain resin, a colorant having a greater affinity for the domain resin than for the matrix resin is used.

The metallic material in the present application means a material capable of obtaining a metallic color tone, and includes not only a conductive metallic material but also a material other than metal and a non-conductive material. .. Examples of such metallic materials include aluminum powder, bronze powder, and pearl pigment. The particle size of these metallic materials is 5 to 80 μm.
m, preferably in the range of 10 to 50 μm. The addition amount (B) (% by weight) of the metallic material is
When the specific gravity of the metallic material used and _{ρ B, 0.45ρ B ≦ B ≦} 15.5ρ B to the toner, and more preferably it is preferred to satisfy the 6.5ρ _B ≦ _B ≦ 13ρ _B. If the particle size of the metallic material is smaller than 5 μm, a metallic image cannot be obtained, and if it is larger than 150 μm, pulverizability, melt-kneading property, fixing property and image reproducibility are deteriorated. According to the present invention, in the case of the conventional mere mixed toner, the metallic material can be added in a larger amount as compared with the case where the metallic material can be contained at most up to about 4ρ _B. It becomes easy to produce a uniformly satisfactory metallic tone. Addition amount is 4.5
If it is less than ρ _B , a sufficiently metallic image cannot be obtained, and if it is more than 15.5 ρ _B , the pulverizability, melt-kneading property and fixing property are deteriorated.

In the present invention, the addition amount is defined by ρ _b because the specific gravity greatly varies depending on the type of the metallic material, and therefore when defined by wt%, the volume ratio of the metallic material contained in the toner to the toner is the metallic material. This is because it depends on the situation.

The toner of the present invention may further contain a low molecular weight olefin polymer, colloidal silica, fatty acid, fatty acid metal salt and the like for the purpose of modifying the fluidity and releasability.

In order to produce the toner of the present invention, first, a kneaded product obtained by melting and kneading the above-mentioned domain resin, colorant and metallic material in the predetermined amounts is obtained. Kneading is done with normal rolls,
It may be performed with a kneader or an extruder. Then, the obtained kneaded product, matrix resin, and dispersion aid are melt-kneaded in the predetermined amounts to obtain a colored composition.

In the obtained coloring composition, a domain resin containing a coloring agent and a metallic material is finely and uniformly dispersed in the matrix resin phase. Such a homogeneous dispersion system, when mechanically blending the matrix resin and the domain resin, the characteristics of the composition components (molecular weight, molecular weight distribution, copolymerization ratio, randomness, electrical characteristics, miscibility,
Affinity, etc.), blending conditions (apparatus, temperature, kneading speed, time, etc.) and the like can be appropriately selected for formation.

The particle size of the domain resin dispersed phase in the matrix resin phase is preferably fine and uniform, but may be about the particle size of the primary particles of the metallic material. The particle size as used herein is an average primary particle size (Martin size) measured by observing a cross section of the sample with an electron microscope.

Finally, the matrix coloring composition in which the domain resin phase is dispersed is pulverized and classified. According to the present invention, since stress is concentrated and pulverized in the matrix resin during pulverization, it is possible to obtain particles whose entire surface is substantially covered with the matrix resin, and moreover, the particle size distribution of the pulverized product. Becomes sharp and the classification yield becomes high. The resulting toner particles are prevented from being adversely affected by the exposure of the colorant and the metallic material, and the charging stability and the like are achieved.

The pulverization can be carried out by means of a jet mill, a hammer mill, a pin mill or the like. In order to effectively impart crushing stress to the matrix resin phase and raise the classification yield, it is preferable to use a low impact crushing means such as a Kryptron crusher (manufactured by Kawasaki Heavy Industries, Ltd.) (FIG. 2).
The Kryptron crusher (FIG. 2) is a vertical high-speed rotary crusher, and has a rotor (201) that rotates at high speed by driving a V-belt (200), an inlet casing (202), an outlet casing (203), and a surface. It is composed of a stator (204) fitted with a liner with multiple grooves. The raw material sucked together with air from the inlet (205) is first evenly distributed around the circumference by the rotor rotating at high speed, and then entrained in the violent vortex generated between the specially shaped rotor blade and the liner blade. It is instantly crushed and pulverized, and is discharged to the outside through the exhaust port (206).

As described above, the fine particles whose surface is covered with the matrix resin (colorant and metallic material are not exposed or exposed very little) can be efficiently classified. Incidentally, the present invention is mainly aimed at formation of a uniform metallic image, classification yield focusing on breakability, and prevention of adverse effects by preventing exposure of colorant and metallic material, but other additives, such as charge control as appropriate. It is possible to add various agents, fluidizing agents, etc. to the matrix resin or domain resin to control various properties, and such embodiments are also included in the present invention.

[0039]

The present invention will be specifically described with reference to the following examples, but the present invention is not limited to the following examples. The domain resin, matrix resin and dispersion aid used in the examples are shown below. Domain resin Styrene / acrylic acid ester copolymer Molecular weight: 53000 Izod impact strength: 0.51 [kgf · cm / cm] Matrix resin Styrene / maleic anhydride copolymer Molecular weight: 10000 Izod impact strength: 0.17 [ kgf ・ cm / cm] Dispersion aid modified styrene polymer Izod impact strength: 0.41 [kgf ・ cm / cm]

Reference Example 1 (Production of Dispersion Aid Resin) In an autoclave having an internal volume of 10 liters, 4 kg of water, 80 g of tricalcium phosphate and 0.12 g of sodium dodecylbenzenesulfonate were added to prepare an aqueous medium. A solution prepared by dissolving 8 g of "Nybar B" in a mixed liquid of 640 g of styrene and 160 g of n-butyl acrylate was added and stirred.
The matrix resin (styrene copolymer) particles 12
00 g was charged, the inside of the autoclave was replaced with nitrogen, the system temperature was raised to 60 ° C., and the temperature was maintained for 3 hours to impregnate the matrix resin particles with styrene containing the above-mentioned polymerization initiator. Then, "Perbutyl PV" 11.4g
Was added to this suspension system, the temperature in the system was further raised to 65 ° C. and maintained for 2 hours to initiate the polymerization of the surface of the styrene polymer particles. Then, the temperature in the system was raised to 90 ° C. and maintained for 3 hours to complete the polymerization. After cooling, the contents were taken out and washed with acid and water to obtain 2 kg of a dispersion aid resin.

Example 1 35 parts by weight of domain resin, blue pigment (Heliogen)
5 parts by weight of Blue D7072D (manufactured by BASF) and metallic material (Sup. Fine Lin. Vlt)
20 parts by weight of ralumin; (true specific gravity 2.7 g / cm ³ ; manufactured by Ecart) was melt-kneaded by a twin-screw kneading extruder. 60 parts by weight of this kneaded material, 42 parts by weight of a matrix resin and 8 parts by weight of a dispersion aid were melt-kneaded by a twin-screw kneading extruder to obtain a colored composition. The colored product obtained is finely pulverized by a jet mill and then classified to have an average particle size of 15
μ toner was obtained. The classification yield at this time was 85%. The obtained toner is sandwiched between a slide glass and a cover glass, and heat-melted on a hot press to form a thin film.
When observed with a transmission optical microscope, the presence of a colored dispersed phase was observed, and the particle size was evenly distributed around 7 μm, with a coloring agent in the small dispersed phase and a metallic material in the large dispersed phase. Was often seen. In addition, no coloring agent or metallic material was found in the matrix.

Comparative Example 1 A coloring composition was obtained in the same manner as in Example 1 except that the dispersion aid used in Example 1 was omitted. When this product was finely pulverized and classified in the same manner as in Example 1, the classification yield was 5
It was 2%. When the obtained toner was evaluated in the same manner as in Example 1, the presence of a dispersed phase was observed, but the particle size was 1.
It was 0 to 9.0 μm and the dispersion was not uniform. Further, the colorant and the metallic material were filled not only in the dispersed phase but also in the matrix phase.

Comparative Example 2 35 parts by weight of domain resin, 50 parts by weight of matrix resin,
Blue pigment (Heliogen Blue D7072
D: BASF) 5 parts by weight and metallic material (Su
p. Fine Lin. 20 parts by weight of Ultralumin; (true specific gravity of 2.7 g / cm ³ ; manufactured by Ecart) was melt-kneaded with a twin-screw kneading extruder to obtain a colored kneaded composition. When the obtained composition was finely pulverized and classified in the same manner as in Example 1, the classification yield was as low as 49% and the particle size distribution was wide. When the obtained toner was evaluated in the same manner as in Example 1, the colorant was almost uniformly dispersed throughout the system, and almost no dispersed phase was observed. The Izod impact strength of this composition was 0.22 [kgf · cm / cm], which was a characteristic close to that of a matrix resin.

Comparative Example 3 A coloring composition was obtained in the same manner as in Example 1 except that the metallic material used in Example 1 was changed to 8 parts by weight. When the obtained colored composition was finely pulverized and classified in the same manner as in Example 1, the classification yield was 84%. When this toner was evaluated in the same manner as in Example 1, the presence of a dispersed phase was observed, and the particle size was uniformly dispersed at around 7 μm. A coloring agent was used in the small dispersion layer and a metallic material was used in the large dispersion phase. Was often seen. No coloring agent or metallic material was found in the matrix.

Comparative Example 4 The domain resin and the matrix resin used in Example 1 were replaced with each other, that is, styrene / maleic anhydride copolymer was used as the domain resin, and styrene / acrylic acid ester copolymer was used as the matrix resin. Using a combination of a styrene-maleic anhydride copolymer that is a domain resin, a surface-treated blue pigment and a metallic material are used to reduce the degree of polymerization as a dispersion aid to reduce Izod impact strength. A coloring composition was obtained in the same manner as in Example 1 except that the agent having 0.29 [kgf · cm / cm] was used. The obtained coloring composition was pulverized in the same manner as in Example 1.
When classification was performed, the time required for pulverization was intermediate between that of Example 1 and Comparative Example 2. Further, the classification yield of this product was as low as 49%. When this toner was evaluated in the same manner as in Example 1, the presence of a dispersed phase was found, but the particle size was 0.8 to 10.0 μ, showing a slight non-uniform dispersion, and a colorant and Some metallic material was seen.

Example 2 In Comparative Example 4, the degree of polymerization was increased and a dispersion aid having an Izod impact strength of 0.6 [kgf · cm / cm] was used.
A colored composition was obtained in the same manner as in Comparative Example 3. When the obtained colored composition was pulverized and classified in the same manner as in Example 1,
Grinding took longer than in Comparative Example 4, but the classification yield was 8
It was as good as 0%. When the obtained toner was evaluated in the same manner as in Example 1, the dispersed phase was uniformly dispersed as in Comparative Example 4, and no colorant was found in the matrix.

Example 3 30 parts by weight of domain resin, blue pigment (Heliogen)
5 parts by weight of Blue D7072D (manufactured by BASF) and metallic material (Sup. Fine Lin. Ult)
Ralumin; (true specific gravity 2.7 g / cm ³ ); manufactured by Ecart Co., Ltd.) 50 parts by weight and the kneaded material obtained by melt-kneading with a twin-screw kneading extruder was used in the same manner as in Example 1. To obtain a colored composition. When this composition was finely pulverized and classified in the same manner as in Example 1, the classification yield was 82%, which was almost the same as in Example 1. When this toner was evaluated in the same manner, it was found that the toner was in the same dispersed state as in Example 1.

Example 4 In Example 1, the matrix resin and the domain resin were replaced with each other, that is, styrene.
A maleic anhydride copolymer is used, a styrene-acrylic acid ester copolymer is used as a matrix resin, 40 parts by weight of a domain resin, and a blue pigment (Heliogen B
lu D7072D; manufactured by BASF) and 5 parts by weight and metallic material (Sup. Fine Lin. Ultra).
50 parts by weight of lumin; (true specific gravity 2.7 g / cm ³ ; manufactured by Ecart) was melt-kneaded with a twin-screw kneading extruder to obtain a kneaded product. 95 parts by weight of this kneaded product, 55 parts by weight of matrix resin and the degree of polymerization are increased to give an impact value of 0.6 [kgf · cm
/ Cm] of 8 parts by weight of the dispersion aid was melt-kneaded with a twin-screw kneading extruder to obtain a colored composition. When the obtained colored composition was finely pulverized and classified in the same manner as in Example 1, the pulverization took a long time, but the classification yield was 81%, which was good. When this toner was evaluated in the same manner as in Example 1, the presence of a colored disperse phase was observed, and the particle size was uniformly dispersed in the vicinity of 7 μm. The small disperse phase contained the colorant, and the large disperse phase contained the colorant. Many metallic materials were seen. No coloring agent or metallic material was found in the matrix resin.

Comparative Example 5 A colored composition was obtained in the same manner as in Example 4 except that a dispersion aid having an impact value of 0.29 [kgf · cm / cm] was used. The obtained coloring composition was pulverized in the same manner as in Example 1.
When classification was performed, the classification yield was 48%. When this toner was evaluated in the same manner as in Example 1, the presence of a dispersed phase was observed, but the particle size was 1.0 to 7.4 μ, showing a slightly non-uniform dispersion, and the matrix resin colorant Some were seen.

Example 5 In Example 1, a pearl pigment (Ir
iodin 153 Fine Satin; (True Specific Gravity 3
g / cm ³ ); manufactured by Merck Ltd.) A coloring composition was obtained in the same manner as in Example 1 except that 30 parts by weight was used. The obtained colored composition was finely pulverized and classified in the same manner as in Example 1 to give an average particle size of 8
A toner of 0 μm was obtained. The classification yield at this time was 85%. When the obtained toner was evaluated in the same manner as in Example 1, the presence of a dispersed phase was observed, and it was dispersed at around 50 μm, and the particle size was almost equal to the primary particles of the pearl pigment.

Comparative Example 6 A colored composition was obtained in the same manner as in Example 5 except that the pearl pigment used in Example 5 was changed to 8 parts by weight. The obtained coloring composition was pulverized and classified in the same manner as in Example 5 to obtain a toner having an average diameter of 80 μm. The classification yield at this time was 86%. When the obtained composition was evaluated in the same manner as in Example 1, the presence of a dispersed phase was observed and the composition was dispersed at about 50 μm.

Comparative Example 7 35 parts by weight of domain resin, 50 parts by weight of matrix resin,
Blue pigment (Heliogen Blue D7072
D; BASF) 5 parts by weight, and pearl pigment (Iri
odin 153 Fine Satin (true specific gravity 3g
/ Cm ³ ); manufactured by Merck & Co.) A coloring composition was obtained in the same manner as in Example 5 except that 30 parts by weight was used. The obtained colored composition was ground and classified in the same manner as in Example 5, but the classification yield was 59% lower. When this toner was evaluated in the same manner as in Example 1, the colorant and the pearl pigment were dispersed throughout the yarn, and the dispersed phase was hardly observed.

The electric resistance and the charge amount of the toners obtained in Examples 1 to 5 and Comparative Examples 1 to 7 were measured. The electric resistance was measured by the impedance bridge method. The charge amount of the toner was measured by a blow-off charge measuring device, and the charge amount after each developer was left under high temperature and high humidity of 30 ° C. and 85% for 12 hours and the charge amount after left for one month at 45 ° C. were measured.

Further, Examples 1, 3, 5 and Comparative Example 1,
30 g of each of toners 2, 3, 6 and 7 and a ferrite carrier (F141-300; manufactured by Powder Tech Co., Ltd.) 50
0 g was mixed with each other to prepare a developer, which was placed in a printer (SP-340; manufactured by Minolta Co., Ltd.) and printed. The images of Examples 1 and 3 and Comparative Examples 1 and 2 had a bluish metallic luster. In Example 5, a bluish pearly luster was exhibited. However, in Comparative Examples 1, 2 and 7, a lot of fog and toner scattering occurred. Further, in Comparative Example 3, although the color tone changed lightly, it did not reach a metallic tone. In Comparative Example 6, the image did not exhibit pearl luster and was an image with unevenness. Similarly, 30 g of each of the toners of Examples 2 and 4 and Comparative Examples 4 and 5 and 450 g of a binder carrier (manufactured by Minolta Co., Ltd.) were mixed and placed in a copying machine (EP4300; manufactured by Minolta Co., Ltd.) for copying. It had a lustrous metallic sheen. However, in Comparative Examples 3 and 4, a large amount of fogging occurred. The above results are summarized in Table 1.

[0055]

[Table 1]

[0056]

The metallic toner of the present invention is excellent in environmental stability of charging characteristics, printing durability, storage stability and metallic tone. According to the method for producing a metallic toner of the present invention, a metallic toner can be produced with good classification efficiency.

[Brief description of drawings]

FIG. 1 shows a schematic cross-sectional view of toner particles of the present invention.

FIG. 2 shows a schematic cross-sectional view of a low-impact crusher (cryptron).

[Explanation of symbols]

1: Matrix resin 2: Domain resin 3: Dispersion aid 4: Colorant and metallic material 200: V
Belt 201: Rotor 202: Inlet casing 203: Outlet casing
204: Stator 205: Inlet 206: Exhaust port

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Internal reference number FI Technical indication location G03G 9/08 368 381 (72) Inventor Shoichi Tsuge 2-3-3 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka No. 13 Osaka International Building, Minolta Camera Co., Ltd. (72) Inventor Minako Sako, 2-3-3 Azuchi-cho, Chuo-ku, Osaka-shi, Osaka City Osaka International Building Minolta-camera Co., Ltd.

Claims (3)

[Claims] 1. A domain resin composition containing a colorant and a metallic material in a domain resin, a matrix resin composition having low miscibility with the domain resin, and both of the domain resin and the matrix resin having miscibility with each other. An electrophotographic toner comprising at least a dispersion aid having an Izod impact value higher than that of a matrix resin, and a domain resin composition dispersed in the matrix resin composition via the dispersion aid. 2. A process of (a) obtaining a kneaded product obtained by melt-kneading a domain resin, a colorant and a metallic material, and (b) having a low miscibility with the kneaded product and the domain resin obtained in the process of (a). A step of melt-kneading a matrix resin and a dispersion aid having miscibility with both the domain resin and the matrix resin and having an Izod impact value higher than that of the matrix resin to obtain a colored composition; (c) (b) The method for producing an electrophotographic toner, which comprises a step of pulverizing and classifying the kneaded product obtained in the step (1). 3. The toner according to claim 1, wherein the colorant and the metallic material are substantially completely filled in the domain resin phase and the dispersion aid.