JPH05249733A - Toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To provide a toner for developing an electrostatic charge image obtd. by suspension polymn., excellent in fixability at a low temp., causing no offsetting phenomenon and capable of giving an image excellent in quality. CONSTITUTION:This toner for developing an electrostatic charge image contains at least a resin and a colorant. The mol.wt. distribution of a THF-soluble component in this toner measured by gel permeation chromatography includes 5-30% region of <=3,000 molwt. and this toner has <=1,000ppm polymerizable monomer and/or org. solvent content.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner which is used in a method for developing an electrostatic latent image and is excellent in low-temperature fixability.

[0002]

2. Description of the Related Art In order to visualize an electric or magnetic latent image or the like on a recording medium, it is possible to adsorb electrostatically-sensitive or magnetic-sensitive fine particles called toner onto the latent image. There is an image forming method using a visual image.

As a typical example of the electrophotographic method, many methods are known as described in, for example, US Pat. No. 2,297,691. In this electrophotographic method, generally, a photoconductive substance is used to form an electric latent image on a photoconductor by various means, and then the latent image is developed with a toner to form a toner image. Then, if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material using heat, pressure, solvent vapor or the like to obtain a copy. At present, a fixing method using heat is predominant in terms of fixing strength of a copy, ease of handling a transfer, and comfort of work. As a heat fixing method, there is a method using radiant heat such as a heat chamber method, but the so-called heat roller fixing method of pressing a heated roll-shaped heating member against a toner image to fix it has high thermal efficiency and high speed compatibility. It is used in most machines because of its high safety.

However, even though the efficiency is high, the energy used for thermal fusing occupies a considerable amount in the copying machine, and the toner adheres to the hot roll because it comes into direct contact with the fused toner image. Then, there is a drawback that a so-called offset phenomenon that stains a subsequent image and a so-called wrapping phenomenon that wraps around a heat roll together with an object to be fixed are unavoidable. In order to reduce the energy required for melting the toner, increase the amount of components that melt at low temperature and reduce the adhesion of the toner to the heat roll. The presence of waxes or oils that fluidize quickly and have a small cohesive energy is effective, but at the same time, these substances have the drawback that the fluidity of the toner is lowered and the developability is significantly lowered.

Conventionally, toners used for these purposes are generally prepared by mixing and melting a coloring material such as a dye / pigment or a magnetic material in a thermoplastic resin to uniformly disperse the coloring material, followed by fine pulverization and classification. By doing so, a toner having a desired particle size has been produced. This method is relatively stable as a technology, and it is possible to manage each material and each process relatively easily.However, since the contents are exposed on the fracture surface, the above-mentioned components for lowering the melting point and It was not possible to contain enough components for mold release to be effective. In this method, the material is mixed with the binder resin and then melted once with the binder resin, and the melted material is cooled and mechanically pulverized. Since it is pulverized easily, the particle size tends to be wide, and it is necessary to adjust the particle size distribution to a desired particle size in the subsequent classification step, and there is a drawback that the product yield cannot be increased. To solve these problems, a toner manufacturing method using a so-called polymerization method has been proposed as a new manufacturing method.

For example, Japanese Patent Publication No. 36-10231, Japanese Patent Publication No. 47-51830, and Japanese Patent Publication No. 51-14895.
JP-A-53-17735, JP-A-53-
No. 17736, JP-A No. 53-17737, etc., there is a toner production method by a so-called suspension polymerization method. In the suspension polymerization method, substances that are required to be encapsulated in the toner, such as binder resins, colorants such as dyes and pigments, magnetic materials, carbon black, charge control agents, release agents such as wax and silicone oil. Is uniformly dissolved or dispersed in a polymerizable monomer together with a polymerization initiator or a dispersant as required to obtain a polymerizable composition, and the polymerizable composition is added to an aqueous continuous phase containing a dispersion stabilizer. After forming fine particles using a disperser, a polymerization reaction is caused to solidify, and at the end of the polymerization, toner particles having a desired particle size are obtained at once.

According to this method, since there is no crushing step,
Since there are no problems related to the crushing method mentioned above, it is hoped that not only the melting process and crushing process but also the subsequent classification process will be omitted, which will save energy, reduce time, improve process yield, and reduce costs. Great effect.

[0008]

The present inventors have found that in suspension polymerization in an aqueous medium, the polymerization starts from the particle interface, the polar component concentrates near the interface, and the nonpolar component gathers in the central part. We have developed a polymerized toner containing a large amount of silicone oil, waxes, or low molecular weight components having a molecular weight of 3000 or less, which cannot be produced or stored by a conventional toner production method that relies on kneading and pulverization. A toner that can be fixed and does not require application of a release agent to the fixing device during fixing was obtained.

In the suspension polymerization method, in the case of a styrene-acrylic vinyl polymerizable monomer, a polymerization initiator of 0.5 to 20 is used.
If the polymerization temperature is set so that the half-life of the initiator is 0.5 to 30 hours, it is possible to obtain a toner composition that can be used as a thermostatting toner.

With this setting, if the polymerization conversion rate is 90% or more, the toner particles will not coalesce into a mochi even if the stirring is stopped, and the toner will be taken out when the polymerization conversion rate reaches 97.8%. When dried, the toner can be used as a toner without any problems.

However, when a large amount of a low molecular weight component is contained in this polymerized toner system, a good quality image can be obtained without any problems under normal environment, but the developability is remarkably deteriorated when left in a high temperature environment. The phenomenon of doing occurred.

An object of the present invention is to provide an electrostatic charge image developing toner which solves the above problems.

Another object of the present invention is to provide an electrostatic charge image developing toner which is fixed at a low temperature and shows a stable and high developing property.

[0014]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner having at least a resin and a colorant and having a molecular weight of 3 in a molecular weight distribution according to gel permeation chromatography (GPC) of a THF soluble component. The range of 1,000 or less is 5% or more and 30% or less, and the content of the polymerizable monomer and / or the organic solvent is 1,000 ppm
It can be achieved by the following.

The toner of the present invention is prepared by forming a droplet having a toner particle size from a polymerizable monomer system obtained by dissolving or dispersing a component required as a toner in an aqueous suspension in a polymerizable monomer. , The polymerizable monomer is polymerized, and finally the content of the organic solvent component in the toner, especially the polymerizable monomer is 1,000.
It can be manufactured by setting the content to be ppm or less.

The present invention will be described in detail below.

As described above, according to the suspension polymerization method, the low molecular weight component and the nonpolar component in the polymer can be encapsulated in the central part of the toner particle. On the other hand, in the suspension polymerization method, the viscosity of the polymerizable monomer system increases as the polymerization reaction progresses, and it becomes difficult for the radical species and the polymerizable monomer to move, and unreacted polymerizable monomer remains in the system. Easy to remain. In the case of the toner by the usual pulverization method, the residual polymerizable monomer can be expelled by the heat applied during the production of the resin for toner or during the melt-kneading, but in the case of the suspension polymerization method toner for directly producing the toner, Since high heat cannot be applied, a large amount of the polymerizable monomer remains in the toner as compared with the normal pulverized toner. If the toner obtained by this suspension polymerization method is left at high temperature in the absence of water, unreacted polymerizable monomers gradually evaporate from the surface, and low molecular weight components and non-polar components inside It is considered that the developing property of the toner is deteriorated due to the fact that the components are conveyed and left on the surface portion.

In the toner of the present invention, it is preferable that 5 to 30% of the region having a molecular weight of 3,000 or less exists in the molecular weight distribution according to GPC of the THF soluble component. Below 5%,
Sufficient fixing property cannot be obtained, and conversely, if it exceeds 30%, sufficient blocking resistance cannot be obtained.

A small amount of volatile organic solvent components are present in the toner in addition to the polymerizable monomer, and the content of all solvent components including these is 1,000 p during production of the suspension polymerization toner.
By controlling to be pm or less, it is possible to obtain a toner that does not deteriorate even when left at a high temperature while encapsulating a large amount of low molecular weight components.

Examples of the polymerizable monomer include styrene-based monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene and p-ethylstyrene, methyl acrylate and acrylic acid. ethyl·
Acrylic esters such as n-butyl acrylate, isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate , Methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate
Methacrylic acid esters such as n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, etc. Other acrylonitrile, methacrylonitrile, acrylamide, etc. Examples of monomers include

These monomers may be used alone or as a mixture. Among the above-mentioned monomers, it is preferable to use styrene or a styrene derivative alone or in a mixture with other monomers, from the viewpoints of developing characteristics and durability of the toner.

In the present invention, a resin may be added to the monomer system for polymerization. For example, a monomer is water-soluble and cannot be used because it dissolves in an aqueous suspension to cause emulsion polymerization, and thus cannot be used as an amino acid, a carboxylic acid group, a hydroxyl group, a sulfonic acid group, a glycidyl group, or a hydrophilic functional group-containing nitrile group. When it is desired to introduce the monomer components into the toner, a random copolymer of these and a vinyl compound such as styrene or ethylene,
It can be used in the form of a copolymer such as a block copolymer or a graft copolymer, or in the form of a polycondensate such as polyester or polyamide, or a polyaddition polymer such as polyether or polyimine. Coexistence of such a polar functional group-containing high molecular weight polymer in the toner causes phase separation of the above-mentioned wax component, strengthens encapsulation, and improves the performance of the toner targeted by the present invention. desirable. The amount used is preferably 1 to 20 wt%. The average molecular weight of the high molecular weight polymer containing these polar functional groups is preferably 5,000 or more. 5,000
When the amount is less than 4,000, particularly 4,000 or less, the present polymer is likely to concentrate near the surface, which is unfavorable since it tends to adversely affect the developability and blocking resistance. Further, when a polymer having a molecular weight different from the molecular weight range of the toner obtained by polymerizing the monomer is dissolved and polymerized, a toner having a wide molecular weight distribution and high offset resistance can be obtained. I can.

As the colorant used in the present invention, known colorants can be used, such as carbon black, iron black, C.I. I.
Direct Red 1, C.I. I. Basic Red 1,
C. I. Mordant Red 30, C.I. I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I.
Basic Blue 5, C.I. I. Modant Blue 7,
C. I. Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6, Yellow Lead, Cadmium Yellow, Mineral First Yellow, Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Tartrazine Lake, Molybdenum Orange GTR, Benzidine Orange G, Cadmium Red 4R, Watching Red. Calcium salt, Brilliant Carmine 3B, Fast Violet B, Methyl Violet Lake, Navy Blue, Cobalt Blue, Alkali Blue Lake, Victoria Blue Lake, Quinacridone, Rhodamine Lake, Phthalocyanine Blue, Fast Sky Blue, Pigment Green B, Malachite Green Lake, Final Yellow. There are pigments such as green G. In the present invention, since a toner is obtained by using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant, preferably surface modification,
For example, it is better to perform a hydrophobic treatment with a substance that does not inhibit polymerization. In particular, since many dyes and carbon black have a polymerization inhibitory property, caution is required when using them. As a preferred method of surface-treating a dye system, there is a method of polymerizing a polymerizable monomer in the presence of these dyes in advance.

The carbon black may be treated in the same manner as the above-mentioned dye, or may be subjected to a grafting treatment with a substance that reacts with the surface functional groups of carbon black, such as polyorganosiloxane or polyethylene glycol. Although other pigments have less strong polymerization inhibiting properties than carbon black, it is better to perform the same treatment in consideration of dispersion in the polymerizable monomer.

In the present invention, a magnetic substance may be added to obtain a magnetic toner, but it is also preferable to use this after surface treatment.

In the present invention, a charge control agent may be added to the toner material in order to control the chargeability of the toner. It is desired that the charge control agent does not have a polymerization inhibitory property or a water phase transfer property, but for example, the positive charge control agent may be a nigrosine dye, a triphenylmethane dye, a quaternary ammonium salt, an amine-based or imine-based dye. Compound,
Examples of the negative charge control agent include metal compounds of salicylic acid or alkylsalicylic acid, metal monoazo dyes, polymers having a carboxylic acid or sulfonic acid functional group, humic acids such as nitrohumic acid, and salts. ..

In the suspension polymerization method of the present invention, a plasticizer is added to the toner in order to improve the low-temperature fixing property or the releasing property when combined with a heat roll fixing device.
Liquid rubber, silicone oil, low-temperature fluidizing components such as wax, and low surface energy substances can be contained.

Examples of the wax include paraffin / polyolefin wax and modified products thereof, such as oxides and graft-treated products, higher fatty acids and metal salts thereof, higher aliphatic alcohols, higher aliphatic esters, and aliphatic amide waxes. And so on. These waxes have a softening point of 30 to 1 according to the ring and ball method (JIS K2531).
Those having a temperature of 30 ° C., preferably 50 to 100 ° C. are desirable. Further, it is desirable to dissolve in a polymerizable monomer. When the softening point is lower than 30 ° C, it becomes difficult to retain the softening point in the toner, and when the softening point is higher than 130 ° C, it is difficult to dissolve it in the polymerizable monomer and the wax is apt to be unevenly dispersed, and Since the viscosity of the composition is increased, the particle size distribution is widened during granulation, which is not preferable. The amount of these waxes added is generally 1 to 100 parts by weight of the polymerizable monomer.
Although 100 parts by weight can be used, if it is 10 parts by weight or more, sufficient releasability and low temperature fixability are obtained.

Silicone oil can be used to further enhance the releasability. The silicone oil used in the present invention preferably has a viscosity in the range of 100 to 100,000 centistokes at 25 ° C. If the amount is out of this range, the releasing effect is lowered, and problems similar to those of wax occur in terms of toner retention and granulation. The amount of silicone oil added is generally 0.1 to 1 per 100 parts by weight of the polymerizable monomer.
It is suitable to use 0 part by weight. Even if it is used in an amount of 10 parts by weight or more, the releasability has already been sufficiently exhibited, and the image surface is only sticky, so addition of more than that is meaningless.

The polymerization initiator used in the present invention has a half-life of 0.5 to 30 hours during the polymerization reaction, and the polymerization reaction is carried out with the addition amount of 0.5 to 20% by weight of the polymerizable monomer. Thus, a polymer having a maximum in the molecular weight of 10,000 to 100,000 can be obtained, and the toner can have desired strength and appropriate melting characteristics. Examples of the polymerization initiator include 2,2′-azobis- (2,4-dimethylvaleronitrile) and 2,2′-
Azo-based compounds such as azobisisobutyl nitrile, 1,1′-azobis (cyclohexane-1-carbonitrile), 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile or Diazo polymerization initiator, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxy carbonate, cumene hydroperoxide, 2,4-
Examples thereof include peroxide type polymerization initiators such as dichlorobenzoyl peroxide and lauroyl peroxide. or,
In the present invention, a known chain transfer agent may be added to adjust the molecular weight.

In the present invention, a crosslinking agent may be added, and the preferable addition amount is 0.001 to 15% by weight.

In the toner manufacturing method of the present invention, generally, the above-mentioned toner composition, that is, a colorant, a releasing agent, a plasticizer, a binder, a charge control agent, a cross-linking agent, a magnetic material, etc., in the polymerizable monomer. Components necessary as a toner and other additives, for example, an organic solvent added to reduce the viscosity of the polymer produced in the polymerization reaction, a dispersant, etc. are appropriately added, and a homogenizer,
The monomer system uniformly dissolved or dispersed by a dispersing machine such as a ball mill, a colloid mill or an ultrasonic dispersing machine is suspended in an aqueous medium containing a dispersion stabilizer. At this time, the particle size of the obtained toner particles becomes sharper by using a high-speed stirrer or a high-speed disperser such as an ultrasonic disperser to immediately make the desired toner particle size. Regarding the timing of addition of the polymerization initiator, it may be added at the same time as other additives are added to the polymerizable monomer, or may be mixed immediately before being suspended in the aqueous medium. It is also possible to add a polymerization initiator dissolved in a polymerizable monomer or a solvent immediately after granulation and before starting the polymerization reaction.

After the granulation, an ordinary stirrer may be used to stir the particles to such an extent that the particle state is maintained and the particles are prevented from floating and settling.

In the suspension polymerization method of the present invention, known surfactants and organic / inorganic dispersants can be used as dispersion stabilizers. Among them, the inorganic dispersants are unlikely to produce harmful ultrafine powders, and due to their steric hindrance. Since the dispersion stability is obtained, the stability is not easily deteriorated even when the reaction temperature is changed, the cleaning is easy, and the toner is not adversely affected. Examples of such inorganic dispersants include polyvalent metal salts of phosphates such as calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, carbonates such as calcium carbonate and magnesium carbonate, and inorganic salts such as calcium metasilicate, calcium sulfate and barium sulfate. Examples thereof include inorganic oxides such as salts, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and alumina.

These inorganic dispersants are composed of the polymerizable monomer 10
It is desirable to use 0.2 to 20 parts by weight per 0 parts by weight, but it is difficult to generate ultrafine particles, but it is somewhat difficult to atomize the toner, so 0.001 to 0.1 parts by weight Some surfactants may be used together.

Examples of the surfactant include sodium dodecylbenzenesulfate, sodium tetradecylsulfate, sodium pentadecylsulfate, sodium octylsulfate,
Examples thereof include sodium oleate, sodium laurate, sodium stearate and potassium stearate.

When these inorganic dispersants are used, they may be used as they are, but in order to obtain finer particles, the inorganic dispersant particles can be generated in an aqueous medium. For example, in the case of calcium phosphate, a water-insoluble calcium phosphate can be produced by mixing an aqueous solution of sodium phosphate and an aqueous solution of calcium chloride under high-speed stirring, and more uniform and fine dispersion is possible. At this time, at the same time, a water-soluble sodium chloride salt is formed as a by-product, but when the water-soluble salt is present in the aqueous medium, the dissolution of the polymerizable monomer in water is suppressed, and the ultrafine toner particles due to emulsion polymerization are used. This is more convenient because it causes a problem and becomes difficult. Since it becomes an obstacle when removing the remaining polymerizable monomer at the end of the polymerization reaction, it is better to replace the aqueous medium or desalt with an ion exchange resin. The inorganic dispersant can be almost completely removed by dissolving it with an acid or an alkali after completion of the polymerization.

In the polymerization step, the polymerization temperature is 40.
Polymerization is carried out at a temperature of not less than 0 ° C, generally 50 to 90 ° C. When the polymerization is carried out within this temperature range, the release agent or wax to be sealed inside is deposited by phase separation, and the encapsulation becomes more complete. At the end of the polymerization reaction, the reaction temperature is set to 90 to consume the remaining polymerizable monomer.
It is possible to raise it to 150 ° C.

Under the above conditions, the conversion rate increases almost linearly up to the polymerization conversion rate of 90%, but the toner solidifies 90
%, The increase in the degree of polymerization is slow, and when the polymerization conversion rate is 95% or more, it is very slow. The polymerization reaction may be advanced as it is to operate so that the amount of the residual polymerizable monomer becomes 1,000 ppm or less, but a known means for promoting the consumption of polymerizable monomer in the conventional suspension polymerization method can be used.

The means adopted in the method for producing a polymerized toner of the present invention is such that when the polymerization conversion rate reaches 95% or more, the temperature is raised by 20 to 60 ° C. to decrease the viscosity due to heat, and the initiation of thermal polymerization. Therefore, the consumption of the polymerizable monomer is promoted. If a polymerization initiator that decomposes at high temperature is coexistent in the polymer system at this time, the consumption of the polymerizable monomer is effectively performed.

Further, the reflux is stopped or the pressure is reduced to partially distill off the unreacted polymerizable monomer and / or the organic solvent so that the residual amount is 1,000 ppm or less. In terms of Instead of keeping it in water, for example while cooling the water vapor to 40-50 ° C,
By exposing the toner particles moistened with water to supersaturated water vapor, the residual amount can be reduced to 1,000 ppm or less, while leaving the same effect as being retained in water.

In addition to this, as a method of increasing the polymerization conversion rate and consuming the polymerizable monomer, an organic solvent serving as a solvent of the toner is added to the polymer system, and a plasticizer is added to the extent that the blocking resistance of the toner is not deteriorated. There is a method of decreasing the viscosity of the polymer system by, for example, adding an amount to the polymer system.

As a method for removing the unreacted polymerizable monomer and / or organic solvent, the toner binder resin is not dissolved but the polymerizable monomer and / or organic solvent component is dissolved. The method of washing with an organic solvent, the method of washing with an acid or an alkali, the solvent component that does not dissolve the foaming agent or the polymer is added to the polymer system, and the resulting toner is made porous to thereby obtain a polymerizable monomer and / or an internal polymerizable monomer. Alternatively, there is a method of increasing the volatilization area of the organic solvent component, but since it is difficult to select the solvent such as the elution of the toner constituents and the residual property of the solvent, the polymerizable monomer and / or the organic solvent component are removed under reduced pressure. The method of volatilizing is the most preferable.

Finally, at least 1000 ppm or less, the polymerizable monomer generated during fixing and the reaction residue thereof,
Alternatively, in order to eliminate the offensive odor caused by the solvent, it is more preferably 100 ppm or less.

The polymerization conversion rate was obtained by adding a polymerization inhibitor to 1 g of the suspension and dissolving this in 4 ml of THF. The amount of the residual polymerizable monomer and the residual organic solvent was 0.2 g of the toner. What was dissolved in 4 ml of THF was measured by gas chromatography by the internal standard method under the following conditions.

G. C. Conditions Measuring apparatus: Shimadzu GC-15A (with a capillary) ^{_{Carrier: N 2, 2Kg / cm 2}} 50ml / min. split ratio 1:60, linear velocity 30 mm / sec column: ULBON HR-1 50 mm × 0.25 mm temperature rise: 50 ° C. 5 min. hold ↓ 10 ° C / min. 100 ° C ↓ 20 ° C / min. 200 ° C. hold Sample amount: 2 μl Labeling substance: Toluene The molecular weight distribution of the toner of the present invention was measured as follows. 1. Sample preparation (i) Standard sample Commercially available standard polystyrene shown below is used as a standard sample.

Molecular weight 8.42 × 10 ⁶ , 4.48 × 1
0 ⁶ , 2.98 × 10 ⁶ , 1.09 × 10 ⁶ , 7.06
× 10 ⁵ , 3.55 × 10 ⁵ , 1.90 × 10 ⁵ , 9.
64 × 10 ⁴ , 3.79 × 10 ⁴ , 1.96 × 10 ⁴ ,
9.10 x 10 ³ , 5.57 x 10 ³ , 2.98 x 10
^3, 870,500 (manufactured by Toyo Soda Kogyo Co., Ltd.) The standard polystyrene about 3
Dissolve mg in 30 ml of tetrahydrofuran (THF) to make a standard sample. (Ii) Unknown sample 60 mg of an unknown sample (toner) is extracted with 15 ml of THF, and after centrifugation, filtration is performed to obtain an unknown sample. 2. Measurement conditions As a device, WATERS 150C ALC / GPC
Was measured under the following conditions.

Solvent: THF (Kishida Chemical's special grade) Column: Shodex KF801, 802, 80
3,804,805,806,807 (Showa Denko) Temperature: 40 ° C Flow rate: 1.0 ml / min Injection rate: 0.1 ml Detector: RI 3. Data processing Under the above measurement conditions, the retention time of the peak top of the standard sample is read, a calibration curve is created, and the molecular weight of the unknown sample is calculated from the calibration curve.

[0049]

EXAMPLES The present invention will be specifically described below based on Examples and Comparative Examples.

Example 1 451 g of 0.1 M Na ₃ PO ₄ aqueous solution was added to 709 g of ion-exchanged water, and the mixture was heated to 60 ° C. and then 1.0 M-
67.7 g of CaCl ₂ aqueous solution was gradually added to Ca ₃
An aqueous medium containing (PO ₄ ) ₂ was obtained.

Styrene 170 g 2-Ethylhexyl acrylate 30 g C.I. I. Pigment Bull-15: 3 10 g Styrene-methacrylic acid-methyl methacrylate (85: 5: 10) Molecular weight (Mw = 58,000) 5 g Paraffin wax (mp. 70 ° C.) 60 g Di-t-butylsalicylic acid metal compound 5 g Above The formulation was heated to 60 ° C. and uniformly dispersed and dissolved at 12,000 rpm using a TK homomixer (made by Tokushu Kika Kogyo). In addition to this, the polymerization initiator 2,2′-azobis (2,4-dimethylvaleronitrile) [t1 / 2 = 14
0 min, under 60 ° C.] 10 g, and dimethyl-2,2 ′
-Azobisisobutyrate [t1 / 2 = 1,270 mi
n, under 60 ° C., t1 / 2 = 80 min, under 80 ° C.] 1 g
Was dissolved to prepare a polymerizable monomer system. The polymerizable monomer system was added to the aqueous medium, and the mixture was mixed at 60 ° C. under N ₂ atmosphere with a TK homomixer at 9,000 rpm for 2 times.
The mixture was stirred for 0 minute to granulate a suspension droplet having a toner particle size. Then, the mixture was reacted at 60 ° C. for 4 hours while stirring with a paddle stirring blade. The polymerization conversion rate at this time was 95%. Then, the reflux of water vapor was stopped, the liquid temperature was raised to 80 ° C., and stirring was continued for 10 hours. After the reaction was completed, the suspension was cooled, hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) _2, and the mixture was filtered,
The polymer was washed with water and dried to obtain a polymerized toner having a weight average diameter of 8.5 μm. This toner was dried at 45 ° C. under reduced pressure of 50 mmHg.
A degassing process was performed for 12 hours. The amount of the polymerizable monomer remaining at this point was 100 ppm. Also, GPC
In the molecular weight distribution according to, the region where the molecular weight was 3,000 or less was 20%.

With respect to 100 parts by weight of the obtained toner, B
0.7 part by weight of hydrophobic silica having a specific surface area of 200 m ² / g according to the ET method was externally added. To 7 parts by weight of this externally added toner, a ferrite carrier 9 coated with an acrylic resin was used.
A developer was prepared by mixing 3 parts by weight.

Using this developer and the externally added toner, an image was printed using a full color copying machine CLC-500 manufactured by Canon Inc. An image with high density was obtained by vivid projection.
The fixing was good and no offset phenomenon was observed. Furthermore, this developer was left in an environment of 35 ° C. for one month,
The image quality was the same as the initial one.

Comparative Example 1 In Example 1, the same state was maintained after 4 hours of reaction, and after a total of 8 hours, when the polymerization conversion rate reached 99% or more, the toner was taken out and the dispersant was washed and dried. Was done.
At this point, the amount of residual polymerizable monomer was 7,000 ppm. When a developer was prepared using this toner in the same manner as in Example 1 and image formation was performed, a good image was obtained, which was the same as in Example 1. However, there was a styrene odor from around the fixing device. When this toner was left for one month in an environment of 35 ° C., the toner tribo was extremely reduced, and an image with a lot of fog was formed.

Examples 2 to 5 and Comparative Examples 2 to 4 In Example 1, the amount of wax, the amount of polymerization initiator, and the polymerization reaction conditions were adjusted to obtain a molecular weight distribution of 3, 3, and 5. Toners having different amounts of residual polymerizable monomer and / or residual organic solvent in the range of 000 or less were manufactured. Table 1 lists the details.

[0056]

[Table 1]

[0057]

According to the present invention, it is possible to obtain an image of excellent quality, which is excellent in low-temperature fixability and has no offset phenomenon.

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Takehiko Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Ichiro Osaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Takayuki Nagatsuka 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A toner comprising at least a resin and a colorant, wherein (1) a THF-soluble component has a molecular weight distribution determined by gel permeation chromatography (GPC) of 5% to 5% in a region having a molecular weight of 3,000 or less. A toner for developing an electrostatic image, comprising 30% of (2) a polymerizable monomer and / or an organic solvent content of 1,000 ppm or less. 2. The toner for developing an electrostatic charge image according to claim 1, which is manufactured by a suspension polymerization method in an aqueous suspension.