JP3336862B2 - Method for producing polymerized toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a toner for developing an electrostatic image used in electrophotography, electrostatic recording, electrostatic printing and the like, and more particularly, to a method for preparing a polymerization initiator by a suspension polymerization method. The present invention relates to a method for producing a polymerized toner which suppresses the amount of decomposition products and residual monomers and has no odor during printing.

[0002]

2. Description of the Related Art Conventionally, in an electrophotographic apparatus, an electrostatic recording apparatus, or the like, an electric or magnetic latent image is visualized by toner. For example, in electrophotography, a toner image is formed by forming an electrostatic charge image (latent image) on a photoreceptor and then developing the latent image using toner. The toner image is usually transferred onto a transfer material such as paper, and then
It is fixed by a method such as heating. The toner used for electrostatic image development is generally a colored particle containing a colorant, a charge control agent, and other additives in a binder resin.The production method is roughly classified into a pulverization method and a pulverization method. There is a suspension polymerization method. In the pulverization method, a toner is manufactured by melt-mixing a colorant, a charge control agent, an anti-offset agent, and the like in a thermoplastic resin, uniformly dispersing the resultant, and pulverizing and classifying the obtained composition. According to the pulverization method, it is possible to produce a toner having excellent properties to some extent, but there is a limitation in selecting a toner material. For example, compositions obtained by melt mixing must be able to be ground and classified by equipment that can be used economically. Due to this requirement, the melt-blended composition must be made sufficiently brittle. For this reason, when actually pulverizing the composition into particles, a high-range particle size distribution is likely to be formed, and in order to obtain a copy image with good resolution and gradation, for example, Fine powder having a size of 5 μm or less and coarse powder having a size of 20 μm or more must be removed by classification, resulting in a disadvantage that the yield is extremely low.
Further, in the pulverization method, it is difficult to uniformly disperse a colorant, a charge control agent, and the like in a thermoplastic resin. Non-uniform dispersion of the compounding agent adversely affects toner fluidity, developability, durability, image quality, and the like.

In recent years, in order to overcome the problems in these pulverization methods, a method for producing a toner by a suspension polymerization method has been proposed and implemented. In the suspension polymerization method, generally, a polymerizable monomer, a colorant, a charge control agent, an offset preventing agent,
The monomer composition obtained by uniformly dissolving or dispersing the polymerization initiator and the like is introduced into water containing a dispersion stabilizer or an aqueous dispersion medium mainly containing water, and using a mixing device having a high shear force. After dispersion, the monomer composition is granulated as fine droplets, and then polymerized to form colored polymer particles (that is, polymerized toner). In the suspension polymerization method, since a colorant or the like is dispersed in a low-viscosity liquid monomer, sufficient uniform dispersibility is secured as compared with a pulverization method in which these compounding agents are added to a resin. Further, according to the suspension polymerization method, a polymerized toner having an extremely sharp particle size distribution can be obtained at a high yield. This polymerized toner has a spherical and uniform surface,
Shows good development characteristics.

[0004] However, the polymerized toner produced by the suspension polymerization method has a problem that it contains residual monomers and low volatile components and has a strong odor. There was a problem of giving. If the amount of the residual monomer is large, filming on the photoreceptor is likely to occur. Conventionally, as a method of reducing the amount of residual monomer and suppressing odor, for example, a depolymerized carbon black is added to a polymerizable monomer, and this is heated and polymerized to produce a prepolymer having a conversion rate of 40% or less. And then
A method has been proposed in which the prepolymer is added to a suspension aqueous solution containing a radical polymerization initiator and subjected to suspension polymerization until the residual polymerizable monomer becomes 0.5% or less (JP-A-60-1985).
243664). However, this method requires a step of preparing a prepolymer, and the step is complicated.

After the suspension polymerization, the resulting resin is heated at a temperature not lower than the glass transition point to distill off 5 to 50% by weight of water based on the amount of water at the end of the polymerization, so that the residual resin in the resin is obtained. A method has been proposed in which the monomer content is 200 ppm or less (JP-A-64-70765). However, this method requires a dehydration step, which not only complicates the process, but also requires energy for dehydration, and further has the disadvantage that the polymer particles tend to aggregate during the dehydration. Actually, the resin obtained by this method is melt-kneaded with carbon black, a charge control agent, and the like, and then pulverized and classified to obtain toner particles. No example of preparation of the particles is given.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a method for producing a polymerized toner free of odor by suppressing the amount of a decomposition product of a polymerization initiator and residual monomers by a suspension polymerization method. It is in. Another object of the present invention is to provide a polymerized toner that has good initial printing quality, excellent image quality stability in continuous printing, and does not cause filming on a photoreceptor by a suspension polymerization method. The present inventors have conducted intensive studies to overcome the problems of the prior art, and as a result, in the process of producing a polymerized toner by a suspension polymerization method,
As a polymerization initiator, a specific organic peroxide is selected and used, and the polymerization temperature is adjusted to be within a specific range to perform suspension polymerization. It has been found that a polymerized toner suppressed to the above can be obtained. The present invention has been completed based on these findings.

[0007]

According to the present invention, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is suspended in an aqueous dispersion medium containing a dispersion stabilizer. In the method for producing a polymerized toner for non-magnetic one-component developer composed of colored polymer particles by polymerizing using a polymerization initiator, the molecular weight is 250 or less as a polymerization initiator
A non-aromatic organic peroxide having a 10-hour half-life temperature of 60 to 85 ° C. and performing suspension polymerization at a polymerization temperature of 75 to 100 ° C. A method is provided.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION In the present invention, a polymerizable monomer composition containing at least a polymerizable monomer and a colorant is charged into an aqueous dispersion medium containing a dispersion stabilizer, and the mixture is stirred. Droplet particles are granulated, and then heated to carry out suspension polymerization to produce a polymerized toner. The polymerization initiator has a molecular weight of 250 or less and a 10-hour half-life temperature of 60 to 85.
Using a non-aromatic organic peroxide at a polymerization temperature of 7 ° C.
The suspension polymerization is performed within a range of 5 to 100 ° C.

Polymerizable monomer As the polymerizable monomer used in the present invention, a monomer having a vinyl group is preferably used. Specific examples of the polymerizable monomer include, for example, styrene, α-methylstyrene,
aromatic vinyl monomers such as p-methylstyrene, p-chlorostyrene and vinyltoluene; unsaturated nitriles such as acrylonitrile and methacrylonitrile; methyl (meth) acrylate, ethyl (meth) acrylate and butyl (meth) Acrylate, 2-ethylhexyl (meth)
Unsaturated (meth) acrylates such as acrylate, lauryl (meth) acrylate and stearyl (meth) acrylate; acrylics such as acrylic acid and methacrylic acid; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene Vinyl halides such as vinyl chloride, vinylidene chloride, vinyl bromide and vinyl fluoride; vinyl esters such as vinyl acetate and vinyl propionate; vinyl ethers such as vinyl methyl ether and vinyl ethyl ether; vinyl methyl ketone; Vinyl ketones such as methyl isopropenyl ketone; nitrogen-containing vinyl compounds such as 2-vinylpyridine, 4-vinylpyridine and N-vinylpyrrolidone; butadiene;
Conjugated diolefins such as isoprene; and the like. These polymerizable monomers can be used alone or in combination of two or more.
The polymerization inhibitor may or may not be present in the monomer.

Along with these vinyl monomers, crosslinking monomers such as aromatic divinyl compounds such as divinylbenzene, divinylnaphthalene, and derivatives thereof;
Di- or tri-ethylenically unsaturated carboxylic esters such as ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, trimethylolpropane triacrylate, 1,3-butanediol dimethacrylate;
Divinyl compounds such as N, N-divinylamyline, divinyl ether, divinyl sulfide and divinyl sulfone, and compounds having three or more vinyl groups can be used alone or in combination of two or more. These crosslinkable monomers can be added before the start of polymerization or during the course of the polymerization, and usually 0 to 20% by weight, preferably 0.1 to 5% by weight, based on all monomers. Used in

Colorant The colorant used in the present invention includes, for example, carbon black, nigrosine base, aniline blue, calco oil blue, chrome yellow, ultramarine blue,
Pigments and dyes such as Orient Oil Red, Phthalocyanine Blue, Malachite Green Oxalate, Rhodamine B, Crystal Violet and the like can be mentioned. The dye / pigment is used in an amount of usually 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer. As the carbon black, those having a primary particle size of 20 to 80 mμ and / or a pH of 7
The above are preferred. Metal oxides such as titanium oxide, silicon dioxide and zinc oxide as coloring agents; magnetic particles such as iron, cobalt, nickel, iron sesquioxide, iron sesquioxide, iron manganese oxide, iron zinc oxide and nickel iron oxide And the like can be used in an appropriate amount. When these metal oxides or magnetic powders are used as a coloring agent, 1 μm
It is preferable to use the following fine particles.

[0012] In the polymerization initiator present invention, a molecular weight of 250 or less of non-aromatic organic peroxide as a polymerization initiator. A non-aromatic organic peroxide having a 10-hour half-life temperature of 60 to 85 ° C. is used.
Can be Such non-aromatic organic peroxides include:
For example, succinic peroxide, t-hexylperoxy 2-ethylhexanoate, t-butylperoxy 2-ethylhexanoate, t-butylperoxyisobutyrate and the like can be mentioned. They are,
Each can be used alone or in combination of two or more. According to the research results of the present inventors, the azo initiator has a strong odor and is difficult to use. In addition, aromatic organic peroxides such as benzoyl peroxide react with a colorant such as carbon black to inhibit the polymerization reaction, and the amount of residual monomers becomes too large. Even among non-aromatic organic peroxides, those having a molecular weight exceeding 250 have a high molecular weight of the decomposition product of the polymerization initiator, do not fly even after drying after the reaction is completed, increase the amount of volatile components, and remain. The amount of monomer is not reduced, and the odor during printing increases.

[0013] Non-aromatic organic peroxide, 10 hours half-life temperature of 6 0 to 85 ° C., good Mashiku is 65-80 ° C. der
You . Here, the 10-hour half-life temperature means a temperature at which the half-life of the organic peroxide is 10 hours. If the 10-hour half-life temperature is lower than 60 ° C., the polymerization temperature will be low, and the amount of residual monomers will increase. When the 10-hour half-life temperature exceeds 85 ° C., the polymerization temperature exceeds 100 ° C., and it becomes necessary to make the polymerization vessel a pressure-resistant vessel. The polymerization initiator is a polymerizable monomer 10
It is used in a proportion of usually 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 0 parts by weight. Since the polymerization initiator is oil-soluble, it can be added to the polymerizable monomer composition.However, in some cases, the polymerization initiator can be added to the suspension after the granulation step of the composition. .

Various additives The polymerizable monomer composition includes a charge control agent, a molecular weight modifier,
A release agent or the like can be added. Examples of the charge controlling agent include nigrosine dye, monoazo dye, gold-containing dye, zinc hexadecyl succinate, alkyl ester or alkyl amide of haphthoic acid, nitrohumic acid, N, N'-
Examples thereof include tetramethyldiaminebenzophenone, N, N'-tetramethylbenzidine, triazine, a metal complex of salicylic acid, and a salt-forming compound of a quaternary ammonium salt and naphtho-sulfonic acid. The charge control agent is usually used in an amount of 0.01 to 5 parts by weight based on 100 parts by weight of the polymerizable monomer.
It is used in a proportion by weight, preferably 0.05 to 3 parts by weight.

Examples of the molecular weight modifier include mercaptans such as t-dodecyl mercaptan, n-dodecyl mercaptan and n-octyl mercaptan; carbon tetrachloride;
Halogenated hydrocarbons such as carbon tetrabromide; and the like. These molecular weight regulators can be added before the start of the polymerization or during the polymerization. The molecular weight modifier is usually based on 100 parts by weight of the polymerizable monomer.
It is used in a proportion of 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight. Examples of the release agent include low molecular weight polyolefins such as low molecular weight polyethylene, low molecular weight polypropylene and low molecular weight polybutylene. The release agent is used in an amount of usually 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerizable monomer. A lubricant such as oleic acid and stearic acid; a dispersing aid such as a silane-based or titanium-based coupling agent; and the like are present in the polymerizable monomer composition for the purpose of uniformly dispersing the colorant in the toner particles. May be. Such lubricants and dispersing aids are usually used in a ratio of about 1/1000 to 1/50 based on the weight of the colorant.

The polymerizable monomer composition of the suspension polymerization method is charged into an aqueous dispersion medium containing a dispersion stabilizer, and stirred to form droplet particles.
Raise the temperature to carry out suspension polymerization. In the present invention, water or an aqueous liquid containing water as a main component can be used as the aqueous dispersion medium. Examples of the dispersion stabilizer include water-soluble polymers such as polyvinyl alcohol, methyl cellulose, and gelatin; poorly water-soluble metal compounds such as calcium phosphate, barium sulfate, calcium sulfate, barium carbonate, calcium carbonate, and magnesium carbonate; Polymer substances; metal oxides such as aluminum oxide and titanium oxide; metal hydroxides such as aluminum hydroxide, magnesium hydroxide and ferric hydroxide; Of these, poorly water-soluble metal compounds are preferred. As a dispersion stabilizer, a poorly water-soluble metal hydroxide formed by a reaction of a water-soluble polyvalent metal salt (eg, magnesium chloride) with an alkali metal hydroxide salt (eg, sodium hydroxide) in an aqueous phase. Salt colloids can be used.

The dispersion stabilizers can be used alone or in combination of two or more. The dispersion stabilizer is usually used in an amount of 0.1 to 100 parts by weight of the aqueous dispersion medium.
It is used in a proportion of 1 to 20 parts by weight, preferably 0.5 to 18 parts by weight. In the present invention, the ratio of the polymerizable monomer composition and the aqueous dispersion medium is not particularly limited, but considering the ease of granulation in the dispersion medium and the dispersion stability of the particles during the polymerization reaction, The concentration of the polymerizable monomer composition in the system is
Usually, 5 to 50% by weight, preferably 10 to 40% by weight,
More preferably, the range is about 20 to 35% by weight.

The granulated polymerizable monomer composition is then
The suspension polymerization is carried out by raising the temperature.
To 100 ° C, preferably 80 to 95 ° C.
When the polymerization temperature exceeds 100 ° C., a pressure-resistant reaction vessel is required, equipment cost is increased, operation is complicated, and danger is increased. If the polymerization temperature is lower than 75 ° C., the amount of the decomposed product of the polymerization initiator and the amount of the remaining monomer will increase, and odor during printing will be a problem. After completion of the suspension polymerization reaction, the dispersion stabilizer remaining on the surface of the polymer particles is usually removed by pickling or washing with water, and thereafter, the polymerized toner is recovered by dehydration and drying. The volume average particle size of the polymerized toner is usually 1
５０50 μm, preferably 5-30 μm, more preferably 2-20 μm. A fluidizing agent such as colloidal silica can be externally added to the polymerized toner.

Image Forming Apparatus The polymerized toner of the present invention is used in an image forming apparatus utilizing electrophotography. The polymerized toner of the present invention is particularly preferably used as a non-magnetic one-component developer in an image forming unit using a non-magnetic one-component development system. FIG.
2 shows a cross-sectional view of an example of the image forming apparatus. In this image forming apparatus, a photosensitive drum 3 as an image carrier is rotatably mounted in a direction indicated by an arrow. The photoconductive layer 2 is provided on the surface of the photoconductor drum 3. The photoconductive layer is composed of, for example, an organic photoconductor, a selenium photoconductor, a zinc oxide photoconductor, an amorphous silicon photoconductor. Around the photosensitive drum, a charging roll 12 is provided along the circumferential direction.
Charging means, a latent image forming means 1, a developing means provided with a developing roll 4, etc., a transfer means 9, and the like. A cleaning device may be arranged at a position before the charging roll 12. The charging means 12 has a function of uniformly charging the surface of the photosensitive drum positively or negatively. In addition to the charging roll 12 illustrated in FIG.
A charging blade or the like can also be used. The latent image forming means 1 irradiates light corresponding to an image signal onto a uniformly charged surface of the photosensitive drum in a predetermined pattern to form an electrostatic latent image on a portion to be irradiated (reversal developing method). Or
An operation of forming an electrostatic latent image on a portion not irradiated with light (regular development method) is performed. The latent image forming means 1 is composed of, for example, a combination of a laser device and an optical system, or a combination of an LED array and an optical system.

The developing means has a function of attaching toner (developer) to the electrostatic latent image formed on the surface of the photosensitive drum, and usually includes a developing roller 4, a developing roller blade 5, a developer accommodating means 7, And developer supply means 8 (supply roller)
It has. The toner 6 is stored in the developer storage unit. The developing roller 4 is disposed so as to face the photoconductor drum 3, and is usually disposed close to a part of the photoconductor drum so as to be in contact with the surface of the photoconductor drum, and rotates in a direction opposite to the photoconductor drum. It is. When the developing roller 4 is rotated, the toner 6 adheres to the outer periphery due to electrostatic force due to friction or the like. The developing roller blade 5 contacts the outer periphery of the developing roller 4 and regulates the thickness of the toner layer. In the reversal developing method, the bias is applied between the developing roller 4 and the photosensitive drum 3 so that the toner adheres only to the light irradiating portion of the photosensitive drum, and in the regular developing method, the toner adheres only to the light non-irradiating portion. A voltage is applied.

The transfer means 9 is for transferring the toner image on the surface of the photosensitive drum to a transfer material 10 such as transfer paper, and may use a corona discharge device, a transfer belt, etc. other than the transfer roller. . The toner image on the transfer material is heated and fixed by a fixing unit such as a heating roller 11. FIG. 1 shows an image forming apparatus that performs a cleaning operation simultaneously with development, but a cleaning unit such as a cleaning blade may be provided if necessary.
Therefore, according to the present invention, there is provided the above-described image forming apparatus including the polymerized toner obtained by the above-described manufacturing method, and a storage unit that stores the polymerized toner.

[0022]

The present invention will be described more specifically below with reference to examples and comparative examples. In the following examples, parts and% are based on weight unless otherwise specified.

Example 1 70 parts of styrene, 30 parts of butyl methacrylate, 2 parts of low molecular weight polypropylene, carbon black (Cabot Corporation, trade name Regal 99R)
7 parts, Cr-based dye (Hodogaya Chemical Co., trade name TRH) 1
Parts and 6 parts of succinic peroxide as a polymerization initiator were dispersed in a ball mill at room temperature to obtain a uniform mixed solution. Next, the above mixture was added to 350 parts of pure water in which 4 parts of calcium phosphate was finely dispersed, and then, under a condition of pH 9 or more, high-shear stirring was performed with a rotor-stator-type homomixer, and the mixture was mixed. Finely dispersed in water. Next, this aqueous dispersion was placed in a reactor equipped with a stirring blade, and polymerized at 80 ° C. for 6 hours with stirring. The polymer dispersion thus obtained was sufficiently washed with acid and water, then separated and dried to obtain a polymerized toner having an average particle size of 8 μm.

To 100 parts of the above polymerized toner, 0.3 part of hydrophobic silica was externally added as a fluidizing agent to prepare a non-magnetic toner. Next, an image forming apparatus using the non-magnetic toner and having the basic configuration shown in FIG. 1, wherein an organic photoconductor is used as the photoconductor 2, and the developing roll 4 is a metal core conductive support. A developing roller blade (toner layer thickness regulating member) 5 having a rubber-based toner carrying layer on the outer peripheral surface is used.
The image evaluation was performed by an image forming apparatus having a contact developing type developing device using urethane rubber.
The obtained image had a high image density and was clear without background stain, dust and unevenness, and a stable image was obtained even in continuous printing of 20,000 sheets. The water content of the toner is 0.1
%, Volatile component 1.2%, residual monomer amount 380pp
m, not noticeable during printing

Example 2 In Example 1, the polymerization initiator was replaced with 6 parts of succinic peroxide.
4. t-hexylperoxy 2-ethylhexanoate
Except for using 6 parts and changing the polymerization temperature to 90 ° C,
A polymerized toner was obtained in the same manner as in Example 1. To 100 parts of the polymerized toner, 0.5 part of hydrophobic silica was externally added as a fluidizing agent to prepare a non-magnetic toner. Next, using this non-magnetic toner, an image evaluation was performed using the same image forming apparatus as in Example 1. The obtained image had a high image density, was free from background smear, dust and unevenness, was clear, and stable image quality was obtained even in continuous printing of 20,000 sheets. The water content of the toner was as low as 0.1%, the volatile component was as low as 0.8%, and the amount of residual monomers was as small as 300 ppm.

Example 3 In Example 1, the polymerization initiator was replaced with 6 parts of succinic peroxide.
A polymerized toner was obtained in the same manner as in Example 1, except that 5 parts of t-butylperoxy 2-ethylhexanoate was used and the polymerization temperature was changed to 90 ° C. To 100 parts of the polymerized toner, 0.5 part of hydrophobic silica was externally added as a fluidizing agent to prepare a non-magnetic toner. Next, using the non-magnetic toner, an image evaluation was performed using the same image apparatus as in Example 1. The obtained image had a high image density, was free from background stain, dust, and unevenness, and was clear, and the image was obtained stably even in continuous printing of 20,000 sheets. The water content of the toner was 0.1%, the volatile component was 1.1%, the residual monomer content was as small as 360 ppm, and no odor was noticeable during printing.

Example 4 In Example 1, the polymerization initiator was replaced with 6 parts of succinic peroxide.
Example 1 was repeated except that 6.8 parts of t-butyl peroxyisobutyrate was used and the polymerization temperature was changed to 95 ° C.
A polymerized toner was obtained in the same manner as described above. This polymerized toner 10
To 0 part, 0.5 part of hydrophobized silica was externally added as a fluidizing agent to obtain a non-magnetic toner. Next, using this non-magnetic toner, an image evaluation was performed using the same image forming apparatus as in Example 1. The obtained image has high image density, background stain,
The image was sharp and free of dust and unevenness, and an image was obtained stably even in continuous printing of 20,000 sheets. The toner has a water content of 0.2%, a volatile component of 1.0%, and a residual monomer content of 3%.
The amount was as low as 40 ppm, and no odor was noticed during printing.

Comparative Example 1 In Example 1, the polymerization initiator was replaced by 6 parts of succinic peroxide.
2,2'-azobis (2-methylpropionitrile) 4
The polymerization toner was obtained in the same manner as in Example 1 except that the polymerization temperature was changed to 85 ° C. To 100 parts of the polymerized toner, 0.5 part of hydrophobic silica was externally added as a fluidizing agent to prepare a non-magnetic toner. Next, using this non-magnetic toner, an image evaluation was performed using the same image forming apparatus as in Example 1. The obtained image had a high image density, was free from background stain, dust and unevenness, and was clear. However, the toner had a water content of 0.1%, a loss on heating of 2.6%, and a residual monomer content of 1600 ppm. The printing was not continued due to a strong odor during printing.

Comparative Example 2 In Example 1, the polymerization initiator was replaced by 6 parts of succinic peroxide.
Polymerized toner was prepared in the same manner as in Example 1 except that 5.6 parts of 1,1,3,3-tetramethylbutylperoxy 2-ethylhexanoate was used, and the polymerization temperature was changed to 85 ° C. I got To 100 parts of the polymerized toner, 0.5 part of hydrophobic silica was externally added as a fluidizing agent to obtain a non-magnetic toner. Next, using this non-magnetic toner, an image evaluation was performed using the same image forming apparatus as in Example 1. The obtained image had a high image density, was free from background stain, dust and unevenness, and was clear. However, the toner had a water content of 0.1%, a volatile component of 3.0%, and a residual monomer content of 16%.
The amount was as high as 00 ppm, and the odor was intensely unbearable during printing.

Comparative Example 3 In Example 1, the polymerization initiator was replaced with 6 parts of succinic peroxide.
A polymerized toner was obtained in the same manner as in Example 1, except that 6.7 parts of benzoyl peroxide was used and the polymerization temperature was changed to 90 ° C. This polymerized toner 100
Part, externally added 0.5 part of hydrophobized silica as a fluidizing agent,
A non-magnetic toner was prepared. Next, using this non-magnetic toner, an image evaluation was performed using the same image forming apparatus as in Example 1. The obtained image had a high image density, was free from background stain, dust and unevenness, and was clear. However, the water content of the toner was 0.1%, the volatile component was 2.8%, and the residual monomer content was as large as 1700 ppm.

Comparative Example 4 In Example 1, 6.7 parts of benzoyl peroxide was used as a polymerization initiator.
Further, a polymerization toner was obtained in the same manner as in Example 1, except that the polymerization conditions were changed to a polymerization temperature of 70 ° C. for 30 hours. To 100 parts of the polymerized toner, 0.5 part of hydrophobic silica was externally added as a fluidizing agent to prepare a non-magnetic toner. Next, using this non-magnetic toner, an image evaluation was performed using the same image forming apparatus as in Example 1. The obtained image had a high image density, was free from background stain, dust and unevenness, and was clear. However, the water content of the toner was 0.1%, the volatile component was 4.5%, and the residual monomer content was as large as 2500 ppm.
These results are collectively shown in Table 1.

[0032]

[Table 1]

(Footnote) (1) The water content of the polymerized toner was measured by a Karl Fischer moisture meter. (2) Heat loss of the polymerized toner was measured by measuring a weight change rate at 105 ° C. for 1 hour. (3) As for the odor of the polymerized toner, ten persons were randomly selected, and when at least half of the persons felt the odor, the evaluation was x, and when there was no one, the evaluation was ○. (4) The amount of residual monomer in the polymerized toner was measured by gas chromatography. In a 10 ml volumetric flask, 0.2 g of the polymerized toner of the sample was precisely weighed, and methanol was added up to the marked line, followed by infiltration for 5 hours. Next, after insoluble matter was precipitated by centrifugation, 1 μl of the supernatant was subjected to GC-MS.
And analyzed for monomer. The GC-MS conditions are described below. Column: HP-1, 0.25 mm × 30 mm, 1 μm Oven: Heated from 50 ° C. to 260 ° C. at a rate of 10 ° C./min INJ. : 220 ° C DET. : 260 ° C. (5) The printing quality is such that the image density is high, the background stain, dust,
A case where there was no unevenness and was clear was evaluated as good (○).

[0034]

According to the present invention, there is provided a method for producing a polymerized toner having no odor by suppressing the amount of a decomposition product of a polymerization initiator and remaining monomers by a suspension polymerization method. According to the production method of the present invention, there is provided a polymerized toner having good initial printing quality, excellent image quality stability in continuous printing, and no filming on a photoreceptor.

[Brief description of the drawings]

FIG. 1 is a cross-sectional view of an example of an image forming apparatus to which a polymerization toner of the present invention is applied.

[Explanation of symbols]

 1: latent image forming means 2: photoconductive layer (photoreceptor) 3: photoreceptor drum 4: developing roll 5: developing roller blade (toner layer thickness regulating member) 6: toner 7: developer accommodating means 8: supply roller 9: transfer roll 10: transfer material (transfer paper) 11: heating roller 12: charging roll

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-5-212271 (JP, A) JP-A-7-152198 (JP, A) JP-A-2-311851 (JP, A) JP-A-7-152 120971 (JP, A) JP-A-7-181731 (JP, A) JP-A-6-332255 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) G03G 9/08 CA ( STN)

Claims (2)

(57) [Claims] 1. A polymerizable monomer composition containing at least a polymerizable monomer and a colorant is suspended in an aqueous dispersion medium containing a dispersion stabilizer, and polymerized using a polymerization initiator. Non-magnetic one-component development composed of colored polymer particles
In a method for producing a polymerized toner for an agent, the molecular weight of the polymerization initiator is 250 or less , and the 10-hour half-life temperature is 60.
A method for producing a polymerized toner, wherein a suspension polymerization is carried out at a polymerization temperature of 75 to 100 ° C. using a non-aromatic organic peroxide at a temperature of from 85 to 85 ° C. 2. A non-aromatic organic peroxide comprising succinic peroxide, t-hexylperoxy 2-ethylhexanoate, t-butylperoxy 2-ethylhexanoate and t-butylperoxy. claim is at least one selected from the group consisting of isobutyrate 1
The method for producing the polymerized toner according to the above .