JPH0561242A - Color toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To provide a color toner for developing an electrostatic charge image having excellent releasability and capable of giving a full-color transparent sheet having excellent transparency and high quality by fixing at a low temp. CONSTITUTION:When a color toner for developing an electrostatic charge image contg. at least resin and a colorant is produced by suspension polymn. in an aq. suspension, low m.p. wax having 10-50% crystallinity and 30-110 deg.C m.p. is incorporated into the toner by 5-50wt.% and the content of an org. solvent and/or a polymerizable monomer is regulated to <=1,000ppm.

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 it is highly efficient, the energy used for heat melting occupies a considerable amount in the copier,
In addition, a so-called offset phenomenon in which the toner adheres to the hot roll to directly stain the fused toner image and stains the subsequent image,
There is a drawback that a so-called winding phenomenon, in which the object to be fixed is wound around the heat roll, is unavoidable.

A conventional method for forming a full-color image will be described below. The photoconductor of the photoconductor drum is uniformly charged by the primary charger, and the image is exposed by the laser light modulated by the magenta image signal of the original, an electrostatic latent image is formed on the photoconductor drum, and magenta toner is retained. The electrostatic latent image is developed by a magenta developing device to form a magenta toner image. Next, the magenta toner image developed on the photosensitive drum is transferred to the transferred transfer material by a transfer charger.

On the other hand, the photosensitive drum after the development of the electrostatic latent image is discharged by the discharging charger, cleaned by the cleaning means, and charged again by the primary charger. Formation of a cyan toner image and transfer of the cyan toner image to the transfer material onto which the magenta toner image has been transferred are performed.
The toner images of four colors are transferred to the transfer material by performing the same procedure as the black color. A full-color image is formed by fixing the transfer material having the toner images of four colors by the action of heat and pressure by a fixing roller.

The toner used in the color image forming method needs to have good melting property and color mixing property when heat is applied to the toner, has a low softening point, and has a low melt viscosity and sharp melt property. It is preferable to use a high toner.

That is, by using such a sharp melt toner, the color reproduction range of the copy can be widened and a color copy faithful to the original image can be obtained.

However, such a color toner having a high sharp melting property has a high affinity with the fixing roller and tends to be offset to the fixing roller during fixing.

Particularly in the case of a fixing device in a color image forming apparatus, since a plurality of toner layers of magenta, cyan, yellow and black are formed on the transfer material, offset tends to occur particularly easily.

Here, conventionally, in order to improve the releasing property of the toner from the fixing roller, a releasing agent such as silicone oil is applied to the fixing roller. However, in such an image forming method, the following problems have occurred.

That is, in the current fixing system in which a releasing agent such as oil is applied to the roller, not only the structure of the main body becomes complicated, but also this oil application promotes shortening of the life of the fixing roller. Harmful.

Further, in accordance with various copying needs in recent years,
It is widely used to pass film-shaped resin, etc., but the transparency film, also known as overhead projector film, is well known.However, in such a fixing method, a sticky feeling due to oil coating is avoided. However, there remains a big problem in the quality of the obtained image.

With respect to these problems, expectations for the establishment of a fixing system that does not require oil coating and the development of a new toner for achieving it have been great.

To solve the above problems, a toner containing a release agent such as wax or a suspension polymerization toner has been proposed (Japanese Patent Publication No. 36-10231). In this suspension polymerization method, a polymerizable monomer and a colorant (and optionally a polymerization initiator, a cross-linking agent, a charge control agent and other additives) are uniformly dissolved or dispersed to form a monomer composition. After that, this monomer composition is dispersed in a continuous phase (for example, an aqueous phase) containing a dispersion stabilizer by using a suitable stirrer, and a polymerization reaction is simultaneously carried out to obtain toner particles having a desired particle size. I will get it.

In this suspension polymerization method, since droplets of the monomer composition are generated in a dispersion medium having a large polarity of water,
The component having a polar group contained in the monomer composition easily exists in the surface layer portion which is the interface with the aqueous phase, and the non-polar component does not exist in the surface layer portion, which is a so-called pseudocapsule structure. By utilizing this characteristic of the manufacturing method, it is possible to contain a wax having a low melting point which cannot be used by other pulverization methods.

In the toner prepared by the polymerization method, inclusion of the low melting point wax makes it possible to achieve both anti-blocking properties and low temperature fixing properties which are contradictory to each other. That is, since the low melting point wax is encapsulated, the wax that melts at a low temperature improves the thermal conductivity in the toner without lowering the anti-blocking performance, and as a result, the low temperature fixing is possible. More preferably, since the wax melted at the time of fixing also functions as a release agent, it is possible to prevent high temperature offset without applying a release agent such as oil to the fixing roller.

However, even when the polymerized toner having wax encapsulated therein certainly exhibits an advantageous performance at the time of fixing, there is a problem that the transparency of the image after fixing is slightly deteriorated when a transparency film is used as the transfer material. It has happened.

It is possible to reduce the amount of the wax contained in order to prevent the deterioration of the image transparency after fixing, but this method reduces the releasability of the toner, and conversely it is sufficient. If it is attempted to encapsulate a certain amount of wax in order to obtain a releasing effect, the above phenomenon cannot be avoided.

Further, in the case of producing a transparency film or the like, the light transmittance of the toner on the transfer material is strongly required, and therefore it is generally well made to slow down the fixing speed to sufficiently melt the toner. In such a case, the toner on the transfer material tends to be more significantly offset during fixing. Therefore, the offset becomes more severe than in the case of fixing the toner layer on the paper, and the amount of the wax encapsulated in the toner must be designed to be large so as to exert a more sufficient releasing effect.

Further, it was confirmed that the decrease in transparency of the transparency film in the method of forming an image by using such a wax-encapsulated toner was cloudy due to crystallization of the wax itself.

[0021]

The present inventor has found that in suspension polymerization in an aqueous medium, the polymerization starts from the particle interface, the polar component is concentrated near the interface, and the nonpolar component is collected in the central part. We have developed a polymerized toner that contains a large amount of wax components that cannot be manufactured by a conventional toner manufacturing method that relies on kneading and crushing, and can fix at low temperature and apply a release agent to the fixing device during fixing. A toner that does not require is obtained.

In the suspension polymerization method, in the case of a styrene-acrylic vinyl polymerizable monomer, the amount of the polymerization initiator is 0.5 to 2
By setting the polymerization temperature to 0% by weight and setting the half-life of the initiator to 0.5 to 30 hours, it is possible to obtain a toner composition that can be used as a thermal fixing 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. When the polymerization conversion rate reaches 97, 8%, the toner particles are taken out. When dried, the toner can be used as a toner without any problems.

However, when a large amount of low-temperature melting wax is contained in this polymerized toner system, a high-quality image can be obtained without any problem under normal circumstances, but when left in a high-temperature environment, the developability is remarkably improved. The phenomenon that the value decreases occurs.

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

Another object of the present invention is to provide a color toner for developing an electrostatic charge image, which is fixed at a low temperature, has excellent releasability, and exhibits stable and high developability.

A further object of the present invention is to provide a color toner for developing an electrostatic charge image, which can be fixed without oil coating to obtain a full-color image of excellent quality.

An object of the present invention is to provide a color toner for developing an electrostatic charge image, which can obtain a full-color transparency sheet having excellent transparency and good quality.

[0029]

The object of the present invention is to provide a toner having at least a resin and a colorant in an amount of 5 to 50% by weight of a low melting point wax having a crystallinity of 10 to 50% and a melting point of 30 to 110 ° C. It can be achieved by adjusting the content of the organic solvent and / or the polymerizable monomer to 1,000 ppm or less.

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, making it difficult for the radical species and the polymerizable monomer to move, and unreacted polymerizable monomer remains in the system. Easy to do. 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 the toner or during the melt-kneading, but in the case of the suspension polymerization method toner which directly produces the toner. Since high heat cannot be applied, a large amount of the polymerizable monomer remains in the toner as compared with the normal pulverization method toner. If the toner obtained by this suspension polymerization method is left at a high temperature in the absence of water, when the unreacted polymerizable monomer gradually evaporates from the surface, low molecular weight components and nonpolar components inside That is, it is considered that the developability of the toner is deteriorated due to the fact that the low melting point wax is conveyed and left on the surface portion. In the toner, a trace amount of a volatile organic solvent component is present in addition to the polymerizable monomer, and the content of all solvent components including these is 1,0 at the time of producing the suspension polymerization toner.
By controlling the amount to be not more than 00 ppm, it was possible to obtain a toner that does not deteriorate even when left at high temperature while encapsulating a large amount of low melting point wax.

The low melting point wax used in the present invention has a softening point of 30 according to the ring and ball method (JIS K2531).
Those having a temperature of ˜110 ° C., preferably 50 to 100 ° C. are desirable. If it exceeds 110 ° C, it becomes difficult to achieve the purpose of low-temperature fixing, and if a large amount is used, granulation becomes difficult.
Also, if the temperature is lower than 30 ° C, it becomes difficult to retain the toner in the toner, and it becomes easy to mix with the binder resin of the toner or the release agent applied to the fixing roller, and the viscosity becomes too low, and conversely the release agent is released. It is not preferable because it deteriorates the property. When the content is 5% or more, the effect on the fixing property appears, and the performance is improved with the increase in the amount used, but when the content is 50% or more, the colorant in the toner is unevenly dispersed and the granulation is unstable. Since adverse effects such as solidification and elution to the surface become remarkable, it is desirable to set it to 5 to 50%, preferably 10 to 40%. In addition, it is desirable that the wax is as non-polar as possible so that it does not emulsify in water and is present deep inside the toner when the present toner is manufactured.

Further, one of the characteristics of the wax used in the present invention is that the crystallinity is 10 to 50%.

As a result of intensive studies by the present inventors, the color toner has a crystallinity of 10 to 50% (more preferably 20 to 35).
%), It has been found that the toner fixability and offset resistance can be improved without impairing the transparency of the transparency image.

When the crystallinity exceeds 50%, the transparency of the transparency image is remarkably deteriorated and the crystallinity is 10%.
If it is less than%, the storage stability and fluidity of the toner deteriorate.

Examples of the wax having a crystallinity of 10 to 50% used in the present invention include polyalkylenes.

The crystallinity of polyalkylene in the present invention is based on the X-ray diffraction method, and the diffraction pattern by the crystal has a sharp peak, and the scattering by the amorphous material is a very broad halo. When crystalline and amorphous are mixed, the ratio of crystalline to the entire sample is called crystallinity.

The total X-ray scattering intensity (intensity of coherent scattering excluding Compton scattering) is always constant regardless of the amount ratio of crystalline to amorphous. Therefore, using a 100% crystalline or amorphous standard sample, the crystallinity χ (%) can be calculated by any of the following equations.

[0040]

[Equation 1] I _c : Scattering intensity of crystalline part of unknown sample I _a : Scattering intensity of amorphous part of unknown sample I _c100 : Scattering intensity of 100% crystalline sample I _a100 : Scattering intensity of 100% amorphous sample As the polyalkylene monomer used for,
Ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, octene-1, nonene-
1, straight chain α-olefins such as decene-1, branched α-olefins having a branched portion at the terminal, and alkylenes having different unsaturated group positions, and the like. Alternatively, copolymerized alkylenes thereof are exemplified.

Examples of the polymerizable monomer constituting the polymerizable monomer system used in the present invention and the toner property imparting agent such as a colorant include the following.

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

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 viewpoint 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. When it is desired to introduce the monomer component of the above 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 of polyester, polyamide or the like, 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
Below, in particular, below 4,000, the present polymer tends 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 in the monomer 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 using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant, and 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 inhibiting 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.

Regarding carbon black, in addition to the same treatment as that of the above dye, it is also possible to carry out 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 are not as strong in polymerization inhibition as carbon black, it is better to perform the same treatment in consideration of dispersion in a polymerizable monomer.

A charge control agent may be added to the toner according to the present invention in order to stabilize the charge characteristics. At that time, a colorless or light-colored charge control agent that does not affect the color tone of the toner is preferable.

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′-
Azos such as azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, azobisisobutyronitrile -Based or diazo-based polymerization initiators, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-
Examples thereof include peroxide-based polymerization initiators such as dichlorobenzoyl peroxide and lauroyl peroxide.

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 release agent, a plasticizer, a binder, a charge control agent, a cross-linking agent, a magnetic material, etc., is added to 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 so 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 the dispersion stabilizer. Among them, the inorganic dispersant is unlikely to produce harmful ultrafine powder, and due to its 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 calcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, and other polyvalent metal salts of phosphate, calcium carbonate, magnesium carbonate, and other carbonates, calcium metasilicate, calcium sulfate, barium sulfate, and the like. Examples thereof include inorganic salts, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, silica, bentonite, and inorganic oxides such as alumina.

These inorganic dispersants are composed of the polymerizable monomer 10
It is preferable to use 0.2 to 20 parts by weight per 0 part by weight, but it is difficult to generate ultrafine particles, but it is somewhat difficult to atomize the toner. Part of the surfactant may be used together.

Examples of the surfactant include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate,
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, a water-soluble sodium chloride salt is by-produced at the same time, 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 It is more convenient because it is less likely to occur. 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 removed almost completely by dissolving with an acid or an alkali after the completion of the polymerization.

In the above-mentioned 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
% Or more, the increase in the degree of polymerization becomes slow, and when the polymerization conversion rate is 95% or more, it becomes 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 include a temperature decrease of 20 to 60 ° C. when the polymerization conversion rate reaches 95% or more to lower the viscosity due to heat, and the initiation of thermal polymerization. Therefore, the consumption of the polymerizable monomer is promoted. At this time, if the polymerization initiator that decomposes at high temperature is allowed to coexist in the polymer system, 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 addition 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 the organic solvent, a highly volatile solvent which does not dissolve the toner binder resin but dissolves the polymerizable monomer and / or the organic solvent component is used. A method of washing with an organic solvent, a method of washing with an acid or an alkali, a solvent component that does not dissolve a foaming agent or a polymer is added to a polymer system, and a polymerizable monomer inside by making the obtained toner porous, and 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 volatilized under reduced pressure. How to make
Most preferred.

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.
What melt | dissolved 2 g in 4 ml of THF was each measured by gas chromatography by the internal standard method on condition of the following.

G. C. Conditions Measuring apparatus: Shimadzu GC-15A (with a capillary) ^{_{Carrier: N 2, 2Kg / cm 2}} 50ml / min. split 10 ml / 13 s column: ULBON HR-1 50 m × 0.25 m
m Hereinafter, the present invention will be specifically described based on Examples and Comparative Examples.

[0065]

Example 1 To 709 g of ion-exchanged water, 451 g of 0.1 M Na ₃ PO ₄ aqueous solution was added, and after heating to 60 ° C., 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 n-Butyl acrylate 30 g C.I. I. Pigment Blue 15: 3 10 g Styrene-methacrylic acid-methyl methacrylate (85: 5: 10) Molecular weight (Mw = 58,000) 5 g Polyalkylene crystallinity 30% (mp.70 ° C.) 40 g Di-t-butylsalicylic acid Chromium complex 5 g The above formulation was heated to 60 ° C., uniformly dispersed and dissolved at 12,000 rpm using a TK homomixer (manufactured by Tokushu Kika Kogyo). In addition to this, the polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) [t1 / 2 = 140
min. at 60 ° C.] 10 g, and dimethyl-2,2 ′
-Azobisisobutyrate [t1 / 2 = 1,270 mi
n. at 60 ° C., t 1/2 = 80 min. at 80 ° C] 1
g was dissolved to prepare a polymerizable monomer system.

The above polymerizable monomer system was put into the above aqueous medium and stirred at 10,000 rpm for 20 minutes at 10,000 rpm in a N ₂ atmosphere at 60 ° C. to form a suspension droplet of toner particle size. Granulated. Then, the mixture was reacted at 60 ° C. for 3 hours while stirring with a paddle stirring blade. The polymerization conversion rate at this point was 90%. 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 and hydrochloric acid was added to add Ca ₃
(PO ₄ ) ₂ was dissolved, filtered, washed with water and dried to obtain a polymerized toner having a weight average diameter of 8.2 μm. This toner 45
Degassing treatment was performed for 12 hours under reduced pressure of 50 ° C. and 50 mmHg. The amount of polymerizable monomer remaining at this point is 15
It was 0 ppm.

To 100 parts by weight of the obtained toner, B
0.7 part by weight of hydrophobic silica having a specific surface area according to the ET method of 200 m ² / g was externally added. To 7 parts by weight of this externally added toner, 93 parts by weight of a ferrite carrier coated with an acrylic resin was mixed to obtain a developer.

Using this developer, images were printed using a commercial color copying machine (CLC-500 Canon) modified. The developing condition was a developing contrast of 320 V under the environment of 23 ° C./65%.

An unfixed image on the transfer just developed and transferred by a modified machine of CLC-500 is an external fixing machine (a fixing roller is a fluorine type soft roller and a pressure roller is a silicon type roller (oil coating). Without function)))
It became established in. The fixing speed is 20 mm / sec. And The obtained fixed image is not offset,
The transparency image was excellent in fixability. When actually projected with an overhead projector, it was a cyan image with excellent transparency. When 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 3 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 6,000 ppm. When this toner was adjusted in the same manner as in Example 1 by adjusting the developer and image formation was carried out, the image was good 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 2-4 and Comparative Examples 2-4 In Example 1, toners having different wax crystallinity and residual polymerizable monomer and / or residual organic solvent were prepared.

Table 1 lists the details.

[0074]

[Table 1]

[0075]

According to the present invention, it is possible to obtain a high-quality full-color transparency sheet which is fixed at a low temperature without oil coating, has excellent releasability, and has excellent transparency.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Office reference number FI technical display location 7144-2H G03G 9/08 384 (72) Inventor Takayuki Nagatsuka 3-30-2 Shimomaruko, Ota-ku, Tokyo No. Canon Inc.

Claims (1)

[Claims] 1. A color toner for developing an electrostatic charge image, which comprises at least a resin and a colorant and is produced by a suspension polymerization method in an aqueous suspension, having a crystallinity of 10 to 50% and a melting point of 3.
A color toner for developing an electrostatic charge image, comprising 5 to 50 wt% of a low melting point wax of 0 to 110 ° C., and containing an organic solvent and / or a polymerizable monomer in an amount of 1,000 ppm or less.