JP2706457B2 - Resin for toner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a resin used for an electrophotographic toner for developing an electrostatic image in electrophotography, electrostatic recording, electrostatic printing, and the like. 2. Description of the Related Art In electrophotography, a copying speed tends to increase with an increase in the amount of information to be processed in recent years. In addition, in electrophotography, it is expected that the copied images have the same quality from the first to tens of thousands of images. Conventionally, in order to obtain a clear image even in high-speed copying,
Attention has been paid to the heat melting properties such as low-temperature fixing property and anti-offset property and the charging stability of the toner, and the resin for the toner has been improved. In order to achieve this object, the present inventors have previously developed a technique using a styrene resin having a lower molecular weight (Mn = 1,000 to 5,000) as a resin for a toner (PCT / JP87 / 008).
19). However, recently, a new problem is vinyl chloride resistance (PVC).
Characteristics have been pointed out. For example, if you copy the amount of money on a sheet of PVC and leave it for one week with weight on it, the copied text moves to the PVC sheet,
For example, there is a big problem that one circle disappears from the copied paper and the amount of money is reduced by one digit. Also, the adhered toner becomes sticky and stains on the PVC sheet side, which is a problem. Although the above-mentioned technology developed by the present inventors is excellent in low-temperature fixing property, anti-offset property, image clarity, etc., it has been found by subsequent studies that the anti-PVC property is not always satisfactory. It is considered that this is because the styrene resin has a strong absorptive power to the plasticizer such as dioctyl phthalate in the PVC sheet, so that the plasticizer migrates to the toner side and the toner is plasticized. DISCLOSURE OF THE INVENTION An object of the present invention is to provide a toner resin having excellent fixability and greatly improved PVC resistance by dissolving a low-molecular-weight polymer in a monomer and dispersing the polymer in an aqueous system, followed by polymerization. It is in. An object of the present invention is to obtain a number average molecular weight of 1,000 to 5,000 obtained by polymerizing a mixed solution of a vinyl monomer, a solvent and a polymerization initiator at a temperature of 190 to 230 ° C, and have a Tg of 40 to 75 ° C. 20 to 80 parts by weight of the low molecular weight polymer and 80 to 20 parts by weight of the vinyl monomer, provided that the total of the low molecular weight polymer and the vinyl monomer is 100
After mixing 0.01 to 5 parts by weight of a polymerization initiator and 0 to 3 parts by weight of a crosslinking agent, the resin is dispersed in an aqueous system and polymerized. BEST MODE FOR CARRYING OUT THE INVENTION The low molecular weight polymer in the present invention was produced by a solution polymerization method under a liquid state by continuously supplying a vinyl monomer, a polymerization initiator and a solvent into a system at 190 to 230 ° C. Things. Vinyl monomers include, for example, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, cyclohexyl acrylate, lauryl acrylate, stearyl acrylate, benzyl acrylate, furfuryl acrylate, acrylic acid Acrylic esters such as tetrahydrofurfuryl, hydroxyethyl acrylate, hydroxybutyl acrylate, dimethylaminomethyl acrylate, dimethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, meth Butyl acrylate, octyl methacrylate, lauryl methacrylate, stearyl methacrylate, cyclohexyl methacrylate, benzyl methacrylate, furf methacrylate Methacrylates such as tetrahydrofurfuryl methacrylate, hydroxyethyl methacrylate, hydroxypropyl methacrylate, hydroxybutyl methacrylate, dimethylaminomethyl methacrylate, and dimethylaminoethyl methacrylate; Aromatic vinyl monomers such as vinyl toluene, α-methyl styrene, chlorostyrene and styrene; unsaturated dibasic acid dialkyl esters such as dibutyl maleate, dioctyl maleate, dibutyl fumarate and dioctyl fumarate; vinyl acetate; Vinyl esters such as vinyl propionate, nitrogen-containing vinyl monomers such as acrylonitrile and methacrylonitrile, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and cinnamic acid, maleic acid, maleic anhydride, Unsaturated dicarboxylic acids such as malic acid and itaconic acid, and unsaturated dicarboxylic acids such as monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monooctyl fumarate Acid monoesters, styrene sulfonic acid, acrylamide, methacrylamide, N-substituted acrylamide, N-substituted methacrylamide,
There are acrylamidopropanesulfonic acid and the like, and at least one of these monomers is used. Among these, acrylic esters, methacrylic esters, styrene, dialkyl fumarate esters, acrylonitrile, methacrylic acid, cinnamic acid, fumaric acid monoesters, acrylamide, methacrylamide and the like are particularly preferable. In the present invention, when a low molecular weight polymer is produced by polymerizing the vinyl monomer, a polymerization initiator is usually used. Examples of the polymerization initiator used include, for example, 2,2'-azobisisobutyronitrile, 2,2'-azobis (4-methoxy-2,4-dimethylvaleronitrile), 2,2'-azobis (-2 , 4-dimethylvaleronitrile), 2,2'-azobis (-2methylbutyronitrile), dimethyl-2,2'-azobisisobutyrate, 1,1'-azobis (1-cyclohexanecarbonitrile), 2- (carbamoylazo)
-Isobutyronitrile, 2,2'-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, 2,2'-azobis (2
Azo initiators such as -methylpropane), ketone peroxides such as methyl ethyl ketone peroxide, acetylacetone peroxide and cyclohexanone peroxide, 1,1-bis (t-butylperoxy)-
Peroxy ketals such as 3,3,5-trimethylcyclohexane, 1,1-bis (butylperoxy) cyclohexane, 2,2-bis (t-butylperoxy) butane, t-
Hydroperoxides such as butyl hydroperoxide, cumene hydroperoxide, 1,1,3,3-tetramethylbutyl hydroperoxide, di-t-
Butyl peroxide, t-butylcumyl peroxide, sicumyl peroxide, 2,5-dimethyl-2,5-
Dialkyl peroxides such as di- (t-butylperoxy) hexane, α, α'-bis (t-butylperoxyisopropyl) benzene, isobutyryl peroxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide Oxides, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, diacyl peroxides such as m-toluoyl peroxide, di-isopropylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate, -N-propyl peroxydicarbonate, di-2-ethoxyethyl peroxycarbonate,
Di-methoxyisopropyl peroxydicarbonate,
Peroxydicarbonates such as di (3-methyl-3-methoxybutyl) peroxydicarbonate, sulfonyl peroxides such as acetylcyclohexylsulfonyl peroxide, t-butylperoxyacetate, t-butylperoxyisobutyrate , T-butyl peroxy neodecanoate, cumyl peroxy neodecanoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxy laurate, t-butyl peroxy neodecanoate
Examples thereof include peroxyesters such as butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, and di-t-butyl diperoxyisophthalate. Among these, it is particularly preferable to use a dialkyl peroxide-based polymerization initiator such as di-t-butyl peroxide, t-butyl cumyl peroxide, and dicumyl peroxide. The amount thereof depends on the reaction temperature, but is usually 0.01 to 10 parts by weight per 100 parts by weight of the charged vinyl monomer.
Used by weight. In the present invention, as a method for producing a low molecular weight polymer by polymerizing the vinyl monomer with a polymerization initiator, solution polymerization is preferable as described above. Solvents used at that time include aromatic hydrocarbons such as benzene, toluene, ethylbenzene, ortho-xylene, meta-xylene, para-xylene, cumene, ethyl acetate, Solvesso # 100, # 150
(Manufactured by Esso Chemical, trade name) and the like, and it is common to use them alone or in combination.
It is also possible to adjust the molecular weight by selecting another solvent. An example in which the low molecular weight polymer is produced by a solution polymerization method will be described in more detail below. That is, as one method, the mixture was previously filled with a mixed solvent and the temperature was 190 to 230 ° C.
A solution prepared by uniformly dissolving and mixing a vinyl monomer, a solvent, and a polymerization initiator into a pressure-resistant reactor heated to a temperature of 1 mm is continuously supplied while maintaining the internal pressure at a constant level, thereby performing polymerization in one or multiple stages. Here, in order to keep the internal pressure constant, a pressure regulating valve which detects and opens and closes the internal pressure is preferably used at the polymerization liquid discharge port. Next, the temperature near the outlet was maintained at the polymerization temperature, and the low-molecular-weight polymer and the mixed solvent were separated by continuously flashing to a vacuum system of about 0 to 200 mmHg to distill off the solvent, etc. A low molecular weight polymer can be obtained. The number average molecular weight of the low molecular weight polymer thus obtained needs to be 1,000 to 5,000, and preferably 1,500 to 2,800. If it is larger than 5,000, it is difficult to fix the toner with a lower calorific value. On the other hand, if it is smaller than 1,000, Tg cannot be maintained at a predetermined temperature or higher, and the blocking property deteriorates. The low molecular weight polymer has a Tg of 40 to 75 ° C, preferably 45 ° C.
If the temperature is lower than 40 ° C., the blocking performance of the resin is deteriorated and the toner does not become toner.On the contrary, if the temperature is higher than 75 ° C., the fixing performance at a low calorific value is deteriorated. I can't get it. In the present invention, the ratio between the low molecular weight polymer and the vinyl monomer to be dissolved is 20/80 to 80/20 by weight, preferably 30.
/ 70 to 70/30. When the amount of the low molecular weight polymer is less than 20/80, fixing performance at a lower calorific value cannot be exhibited, and
If it is larger than 0, the strength of the resin decreases, and even if it is fixed on paper, it has no strength and can be easily removed. In addition, the offset phenomenon occurs and the image quality deteriorates. In the present invention, the low molecular weight polymer thus obtained is dissolved in a vinyl monomer and polymerized. As a polymerization method, a solution polymerization method, an emulsion polymerization method, and a suspension polymerization method are generally employed. In the present invention, a suspension polymerization method of dispersing in an aqueous system is employed. The solution polymerization method is difficult to polymerize because of the chain transfer by the solvent, and even if it can be polymerized, it has a high viscosity and is difficult to handle. In addition, the emulsion polymerization method cannot be emulsified because a low molecular weight polymer is contained in a vinyl monomer. Therefore, the simplest suspension polymerization method is used. That is, the low-molecular-weight polymer described above is mixed and dissolved in the above-mentioned vinyl monomer with stirring, and further a crosslinking agent and a small amount of a polymerization initiator are added and dissolved, and then water, polyvinyl alcohol, and a dispersion stabilizer such as gelatin are added. After the suspension, the mixture is heated to carry out polymerization. In suspension polymerization, it is preferable to use a crosslinking agent. The use of a crosslinking agent significantly improves the resistance to PVC. As the crosslinking agent to be used, a compound copolymerizable with the vinyl monomer can be used. For example, divinylbenzene, (poly) ethylene glycol diacrylate,
(Poly) ethylene glycol dimethacrylate can be used. The larger the amount used, the larger the gel portion and the better the PVC resistance. The preferred amount of the crosslinking agent is 0.05 to 3 parts by weight, more preferably 0.05 to 1 part by weight, based on 100 parts by weight of the total of the low molecular weight polymer and the vinyl monomer. If the amount is less than 0.05 part by weight, there is almost no effect. If the amount is more than 3 parts by weight, the thickening effect is so severe that the thermal fluidity is deteriorated, and it becomes difficult to fix the toner at a lower calorific value. The gel portion means an insoluble portion when dissolved in tetrahydrofuran, and the insoluble portion is preferably 2 to 48% by weight. As the polymerization initiator used in the suspension polymerization, any of the aforementioned polymerization initiators can be used, and preferred polymerization initiators are also the same. As the polymerization initiator, it is preferable to use two or more of a polymerization initiator used for the purpose of promoting a normal polymerization reaction and a polymerization initiator used for the purpose of reducing residual monomers. The latter polymerization initiator usually has a higher decomposition half-life than the former. The amount of the former is preferably 0.01 to 4.0 parts by weight, and the latter is preferably 0 to 1.0 part by weight, based on 100 parts by weight of the total of the low molecular weight polymer and the vinyl monomer, and the total is 0.01 to 5 parts by weight. If the amount is less than 0.01 part by weight, the time required for the polymerization is too long, and if it is more than 5 parts by weight, it is difficult to polymerize the polymer, and the amount of residue of the polymerization initiator is increased, which adversely affects the electrical properties. Not preferred. In the present invention, when a vinyl monomer in which a low molecular weight polymer, a cross-linking agent, and a polymerization initiator are dissolved is dispersed in an aqueous system, in order to stabilize suspended particles, dispersion stability of commonly used polyvinyl alcohol, gelatin, etc. is stabilized. Agent, surfactant, pH
Conditioning agents, inorganic additives such as calcium phosphate and magnesium carbonate can be used. The dispersion in water in this way is heated to 60 to 90 ° C. for polymerization, and then polymerization for removing residual monomers is performed.
Perform at 80-120 ° C. After completion of the polymerization, the resin for toner of the present invention can be obtained by thoroughly washing to remove the dispersion stabilizer, followed by filtration and drying. The toner used for the resin of the present invention is mainly a dry toner in a powder form, and the resin as a main component thereof needs to be solid at room temperature, and when the toner is used,
It is necessary not to cause blocking by leaving for a long time. From such a viewpoint, the glass transition point of the resin is
It is preferably at least 40 ° C, more preferably at least 50 ° C.
It is also preferable to soften at as low a temperature as possible from the viewpoint of low-temperature fixability, and from this viewpoint the glass transition point is 90 ° C. or less,
Further, the temperature is preferably 80 ° C. or lower. As long as the resin of the present invention does not impair the effects of the present invention as necessary, for example, polyvinyl chloride, polyvinyl acetate, polyolefin, polyester, polyvinyl butyral, polyurethane, polyamide, rosin, modified rosin, terpene resin, phenol resin, Addition resins or additives such as aliphatic hydrocarbon resins, aromatic petroleum resins, paraffin waxes, and polyolefin waxes may be partially used. The resin of the present invention can be mixed with a colorant to form a toner. Examples of the coloring agent to be used include black pigments such as caborne black, acetylene black, lamp black, and magnetite, graphite, yellow iron oxide, Hansa Yellow G, Quinoline Yellow Lake, and Permanent Yellow NC.
G, Molybdenum Orange, Vulcan Orange, Indanthrene, Brilliant Orange GK, Bengala, Brilliant Carmine 6B, Frizarin Lake, Methyl Violet Lake, Fast Violet B, Cobalt Blue,
Known organic and inorganic pigments such as alkali blue lake, phthalocyanine blue, fast sky blue, Pigment Green B, malachite green lake, titanium oxide, zinc white and the like can be mentioned. The amount is usually 5 to 250 parts by weight based on 100 parts by weight of the resin. The resin for toner of the present invention can be made into a toner by a known method by appropriately selecting and adding known charge adjusters such as nigrosine and metal-containing azo dyes, a pigment dispersant, an offset preventing agent, and the like. . That is, the resin mixture to which the various additives have been added is premixed in a powder form, then kneaded in a hot-melt state with a kneader such as a hot roll, a Banbury mixer, or an extruder, and cooled, and then finely pulverized using a pulverizer. Pulverize and classify with a pneumatic classifier, usually 8-20
The particles in the range of μ are collected to form a toner. Hereinafter, the present invention will be described more specifically with reference to Examples. Units are parts by weight or% by weight unless otherwise specified. The number average molecular weight (Mn) was measured by GPC under the following conditions. GPC equipment: JASCO TWINCLE HPLC DETECTOR: SHODEX RI-SE-31 COLUMNE: SHODEX GPCA-80M x 2 + KF-802 x 1 Solvent: tetrahydrofuran (THF) Flow rate: 1.2 ML / MIN Sample: 0.25% THF solution The characteristics were measured under the following conditions using an electrophotographic copying machine EP870 (manufactured by Minolta Camera Co., Ltd.) using a Teflon heat roll. Fixing property: Reciprocated 20 times with constant force between erased solid black part and white background with eraser (Plastic eraser "MONO" manufactured by Tombo Pencil Co., Ltd.) to remove toner from solid black part and to white background Observe dirt, ◎ (do not fall off at all),
（(Good), Δ (slightly falling off), × (dropping off <many stains poor). Underground dirt: The 100th and 10,000th white background areas in continuous copy are compared, and the degree of dirt on the white background areas due to the effects of scattering, etc. is severe. ○ (good), △ (magnifying glass with a magnification of 30 times) , And dirt (contamination can be confirmed with the naked eye). Offset: A phenomenon in which the toner partially adheres to the fixing roll side, and the roll further adheres to the background of the paper after one rotation, causing the paper to be distorted, is called offset, and does not occur during continuous copying of 10,000 sheets. The thing was marked with ○ and the thing that caused it was marked with ×. Blocking resistance: Left at 50 ° C. for 1 week. A sample that did not cause any blocking was evaluated as ○, a device that slightly blocked but collapsed with a small force was rated Δ, and a device that caused blocking and did not collapse with a small force was rated X. PVC resistance: Place a PVC sheet on the copied paper and place it on top
After a weight of 100 g / cm ² was applied and left at 40 ° C. for one week, the polyvinyl chloride sheet was peeled off, and the condition when peeling off and the state of toner adhesion were observed.と き When peeling off the PVC sheet and the copy, no force is applied, and no abnormality is recognized in both the PVC sheet and the copy paper. ○ There is no toner attached to the PVC sheet, but it makes a clicking noise and a part of the toner is sticky. Δ Some toner was transferred to the PVC sheet, but most remained on the copy paper side. C: Most of the toner has migrated to the PVC sheet side. Example 1 A solution prepared by uniformly dissolving 0.5 part of di-t-butyl peroxide per 100 parts of styrene in a mixed solution of 70 parts of styrene, 30 parts of a mixed solvent of xylene and ethylbenzene, was heated to an internal temperature of 210 ° C and an internal pressure of 6 kg / kg. 75 in 5 reactors held at cm ²
The polymerization was carried out by continuously supplying at 0 cc / hr. 200 ° C, 10m
The solution was flushed into a mHg vessel to distill off the solvent and the like. The number average molecular weight of the obtained low molecular weight polymer (A) is 2,10
It was 0 and Tg was 57 ° C. 50 parts of the obtained low molecular weight polymer (A) is dissolved in 30 parts of styrene and 20 parts of n-butyl methacrylate, and 0.5 part of benzoyl peroxide and perbutyl I (t-butyl peroxyisopropyl carbonate Nippon Oil & Fat) are further added. 0.2 parts,
0.1 part of ethylene glycol dimethacrylate is added,
The mixture was uniformly dissolved, added to 1 cc of water to which 1 part of polyvinyl alcohol and 5 parts of calcium hydrogen phosphate were added, and dispersed in a suspension. This was heated to 80 ° C. and polymerized for 8 hours. Then, the mixture was heated to 120 ° C. under pressure, and the remaining monomers were polymerized for 3 hours. Then, the water was filtered off, washed twice with water, and then dried. 100 parts of the resin thus obtained were mixed with 7 parts of carbon black (MA-100 manufactured by Mitsubishi Kasei), 2 parts of a charge control agent (Spiron Black TRH manufactured by Hodogaya Chemical), and 5 parts of polypropylene wax (Viscol 550P manufactured by Sanyo Chemical). Together with a Henschel mixer to obtain a lump of toner. Then, after coarsely crushed to about 1 mm, finely crushed by a jet mill, and classified by an air classifier, 5 to 20 μm, average particle size of about 11 μm
m of toner particles were obtained. 4 parts of the above toner, 100 parts of ferrite carrier (F-150 made by Nippon Iron Powder) and Erosil (R-972 made by Nippon Erosil)
0.2 part was mixed with a V-type blender to obtain a two-component developer. Table 1 shows the result of examining the copying suitability of this developer. Examples 2 to 5, Comparative Examples 1 and 2 In Example 1, the production temperature of the low molecular weight polymer was 190,
A toner was prepared in exactly the same manner except that the temperature was changed to 200, 220, 230, 180, 240 ° C., and the suitability for copying was examined. The results are shown in Table 1. Comparative Example 3 A suspension polymerization was carried out in the same manner as in Example 1 except that the low-molecular-weight polymer (A) was not dissolved, followed by washing and drying. Example 1 was prepared using a mixture of 50 parts each of the resin (B) thus obtained and the low molecular weight polymer (A).
A developer was obtained in exactly the same manner as described above. The copying suitability of this developer was examined, and the results are shown in Table 1. Examples 6 and 7, Comparative Examples 4 and 5 In Example 1, the ratio of the low molecular weight polymer (A) and the vinyl monomer to be subjected to suspension polymerization was 70/30, 30/70, 90/10 and 1
A toner was manufactured in exactly the same manner as in Example 1 except that the ratio was changed to 0/90, and the suitability for copying was examined. The results are shown in Table 2. Comparative Example 6 A toner was produced in the same manner as in Example 1 except that 70 parts of styrene was changed to 56 parts of styrene and 14 parts of butyl acrylate, and the suitability for copying was examined. The results are shown in Table 2. Examples 8 to 11 and Comparative Examples 7 to 8 The copy suitability was determined in exactly the same manner as in Example 1 except that the conditions for the suspension polymerization were changed to those shown in Table 3, and the results are shown in Table 3. Indicated.

Claims (1)

(57) [Claims] A number average molecular weight of 1, obtained by polymerizing a dissolved mixture of a vinyl monomer, a solvent and a polymerization initiator at a temperature of 190 to 230 ° C.
000 to 5,000 and a low molecular weight polymer 20 having a Tg of 40 to 75 ° C.
-80 parts by weight, 80-20 parts by weight of a vinyl monomer, provided that the total of the low molecular weight polymer and the vinyl monomer is 100 parts by weight, 0.01-5 parts by weight of a polymerization initiator and 0-3 parts by weight of a crosslinking agent A resin obtained by mixing and then dispersing and polymerizing in an aqueous system as a main component. 2. The vinyl monomer is at least one selected from acrylic acid esters, methacrylic esters, styrene, dialkyl fumaric esters, acrylonitrile, methacrylic acid, cinnamic acid, fumaric monoesters, acrylamide, and methacrylamide. The resin for toner according to claim 1. 3. 2. The resin for toner according to claim 1, wherein the number average molecular weight of the low molecular weight polymer is from 1,500 to 2,800. 4. The resin for toner according to claim 1, wherein the glass transition temperature of the low molecular weight polymer is in the range of 45 to 70 ° C. 5. 30/70 weight ratio of low molecular weight polymer to vinyl monomer
The resin for a toner according to claim 1, wherein the ratio is from 70 to 30/30. 6. Polymerization in aqueous dispersion polymerization involves mixing and dissolving a low molecular weight polymer in a vinyl monomer, dissolving a crosslinking agent and a polymerization initiator, further adding water and a dispersion stabilizer to form a suspension state, and then heating and polymerizing. 2. The resin for toner according to claim 1, which is a resin. 7. 2. The method according to claim 1, wherein the amount of the crosslinking agent is 0.05 to 3 parts by weight.
The resin for a toner according to the above item. 8. 2. The resin for toner according to claim 1, wherein the polymerization initiator uses both (A) for promoting the polymerization reaction and (B) for reducing residual monomers. 9. 9. The resin for toner according to claim 8, wherein (A) is 0.01 to 4.0 parts by weight and (B) is 0 to 1.0 parts by weight. 10. 2. The resin for toner according to claim 1, wherein the polymerization in the aqueous dispersion polymerization is carried out by a first-stage polymerization at 60 to 90 ° C. and a second-stage polymerization at 80 to 120 ° C. 11. A glass transition temperature of 50 to 75 ° C.
The resin for a toner according to the above item. 12. 2. The resin for toner according to claim 1, wherein an additive resin or an additive is further added to the resin for toner. 13. Number average molecular weight obtained by polymerizing a dissolved mixture of vinyl monomer, solvent and polymerization initiator at a temperature of 190 to 230 ° C
Low molecular weight polymer with 1,000 to 5,000 and Tg of 40 to 75 ° C
20 to 80 parts by weight, 80 to 20 parts by weight of vinyl monomer, provided that the total of the low molecular weight polymer and the vinyl monomer is 100 parts by weight,
A toner containing a resin for toner obtained by mixing 0.01 to 5 parts by weight of a polymerization initiator and 0 to 3 parts by weight of a crosslinking agent, and then dispersing and polymerizing in an aqueous system. 14． 14. The toner according to claim 13, wherein the colorant is contained in an amount of 5 to 250 parts by weight based on 100 parts by weight of the toner resin.