JPH03131867A - Production of toner for developing electrostatic charge image - Google Patents

Abstract

PURPOSE:To save labor, time, energy and cost by executing graft-modification treatment with a vinyl monomer in the copresence of specific components, adding the graft-modification treated matter into a polymerizable toner compsn. essentially composed of the vinyl monomer and subjecting the compsn. to suspension polymn. CONSTITUTION:Since the graft polymn. of polyolefin wax is executed in the presence of a coloring agent and charge control agent, the graft polymn. to multifunctional groups on the surfaces of the particles of the coloring agent, charge control agent, etc., dispersed in this system is effected together with the graft polymn. of the wax. The grafted wax are grafted or securely adsorbed and combined therewith. The graft-modification treated matter obtd. in such a manner is added and dissolved or dispersed to the polymerizable toner compsn. essentially composed of the vinyl monomer, by which the grafted wax is uniformly dissolved and dispersed into the polymerizable toner compsn. together with the dispersion of the coloring agent, charge control agent, etc. This compsn. is suspended into an aq. phase contg. a suspension stabilizer and is subjected to suspension polymn. The labor, time, energy and cost are saved in this way.

Description

Detailed Description of the Invention (Field of Industrial Application) The present invention relates to a method for producing a toner for developing electrostatic images using electrophotography, electrostatic printing, electrostatic recording, etc. The present invention relates to a method for efficiently producing a toner that has excellent binding properties with wax and has excellent fixing properties, fluidity, anti-offset properties, printing durability, etc.

(Prior art) Generally, in the dry development method, an electrostatic image is developed using a powder developer consisting of a toner containing a coloring agent dispersed in a binder resin. The image is transferred to an image support and then fixed. As a method for this fixing, a heat fixing method is advantageous. In particular, a contact heat fixing method represented by a heat roller fixing device has higher thermal efficiency than a non-contact heat fixing method such as a hot plate fixing device, and is particularly suitable for high-speed fixing. It is suitable for fixing in high-speed copying machines.

In order to effectively utilize such a contact heating method, and to achieve the ability to form developable images on both sides of a single sheet of transfer paper, which has been in high demand recently, it is necessary to fix the developing toner at a low temperature. Moreover, it is necessary to have excellent releasability from the fixing heating roller. For this reason, techniques have been developed in which a low softening point wax made of a release agent such as polypropylene wax or polyethylene wax is contained in toner particles.

Conventionally, toners containing wax are produced by adding colorants, wax, charge control agents, and other toner components to a thermoplastic resin as a binder, contact-kneading the mixture, and finely pulverizing and classifying the kneaded product. Manufactured. however,
Toner manufactured by this so-called pulverization method requires a large amount of energy to melt and knead the materials, and the manufacturing equipment is also large-scale, making the manufacturing cost extremely high.

Further, the toner obtained by the pulverization method is irregular in shape, has low fluidity, and has drawbacks such as the chargeability of each particle being different. Therefore, toner production by a suspension polymerization method has been proposed as a method for simplifying the production process, reducing production costs, and producing a spherical toner with improved fluidity and charging characteristics all at once.

However, in this suspension polymerization method for producing toner, it is difficult to uniformly and uniformly disperse the wax component in a polymerizable composition made of polymerizable monomers, and it is difficult to obtain the effect of adding wax. The content of wax must be considerably increased, and the problem arises that the Fuchs component is liberated from the generated toner particles.
Problems have arisen, such as the fluidity of the toner being reduced, wax components forming on the developing sleeve or electrostatic image support, and toner agglomeration in the developing device. Therefore, various proposals have been made to solve these drawbacks. In other words, JP-A-60
No. 23860 discloses an electrostatic charge image containing a polymer obtained by polymerizing a polymerizable monomer in the presence of a wax made of a polyolefin that has been block copolymerized or graft copolymerized with an aromatic vinyl polymer. A toner for use in and a method for producing the same is described. Also, JP-A-60
-83040 discloses a polymer containing a polymer obtained by polymerizing a polymerizable monomer in the presence of a wax made of a polyolefin block copolymerized or graft copolymerized with an aromatic vinyl monomer. The value of the ratio of the weight average molecular weight to the number average molecular weight of the coalesce is 3
．． Five or more electrostatic image toners and methods for producing the same are described.

Furthermore, in Japanese Patent Application Laid-Open No. 60-83039,
Publication No. 0-83040 discloses a toner for electrostatic images using a polyolefin wax obtained by block copolymerization or graft copolymerization in which aromatic vinyl monomer is changed to an α-methylene aliphatic monocarboxylic acid ester monomer, and a method for producing the same. Are listed.

Furthermore, JP-A-61-123854 describes a method for producing a toner in which pigments are dispersed in the presence of a grafted polyolefin, and re-agglomeration of the pigments does not occur due to the thickening effect of the grafted polyolefin.

The above prior art techniques all aim to improve the fixing properties, anti-offset properties, dispersibility, etc. of polymerized toners. After the completion of the suspension polymerization, the toner composition is dissolved or dispersed in a polymer monomer containing the toner composition, and suspension polymerization is carried out.
This process involves a large number of steps to obtain toner.

In any of the above methods, the dispersibility of the wax in the polymerizable composition is still insufficient, and the resulting toner has insufficient binding properties of the wax with the toner composition. In a printing durability test of about 20,000 sheets, the wax sometimes films on the drum or sticks in the developing device, reducing the developability, and it has not been possible to obtain fully satisfactory results.

Further, although it is said in Japanese Patent Application Laid-Open No. 61-123854 that the effect of preventing re-aggregation of pigments can be obtained, when the present inventors conducted a check, no significant effect was found.

Therefore, it is an object of the present invention to produce a spherical toner in which wax is uniformly finely dispersed, and has excellent binding properties between the wax and the toner composition including the binder resin, and in which color pigments are uniformly dispersed. The purpose is to provide a manufacturing method.

Another object of the present invention is to provide a method for producing toner by suspension polymerization, which has a significantly simplified process compared to conventional production methods.

Furthermore, another object of the present invention is to form images that have excellent offset resistance, agglomeration resistance, coloring properties, fluidity, and charging stability and are excellent for a long period of time without contaminating an image carrier or the like. The object of the present invention is to improve the manufacturing method of spherical toner.

(Means for Solving the Problems) According to the present invention, a polyolefin wax is mixed with at least 1 f selected from the group consisting of a coloring agent and a charge control agent.
Graft modification treatment is performed with a vinyl monomer in the coexistence of ffi components, and the graft modification product is added to a polymerizable toner composition mainly composed of a vinyl monomer to perform suspension polymerization. A method for producing a toner for developing an electrostatic image is provided.

(Function) The method for producing a toner for developing an electrostatic image of the present invention includes at least 1f polyolefin wax carried by a group consisting of a colorant and a charge control agent. A step of performing graft polymerization treatment with a vinyl monomer in the coexistence of the components of It is characterized by the process of

Since the graft polymerization of polyolefin wax is carried out in the presence of colorants and charge control agents, along with the graft polymerization of wax, the particles of colorants, charge control agents, etc. dispersed in this system also have their polyfunctional properties. Graft polymerization occurs on the base, and the grafted wax is grafted onto it or firmly adsorbed and bonded to it. When the graft-modified product obtained in this way is added to a polymerizable composition mainly composed of vinyl monomers and dissolved or dispersed, the grafted wax becomes a polymerizable toner along with the dispersion of colorants, charge control agents, etc. It can be uniformly dissolved or dispersed in a composition, and by suspending it in an aqueous phase containing a suspension stabilizer and subjecting it to suspension polymerization, polymer particles with a desired particle size can be obtained as a toner. In these toner particles, the colorant, charge control agent, grafting wax, other modifiers, etc. inside the particles are integrally bonded to the toner resin (fixing resin), and each particle has a uniform composition. It will be done.

The grafted wax in the toner particles is combined with the colorant, charge control agent, etc., so the binding property with the fixing resin is significantly improved and strong, and the wax does not separate from the toner. Printing durability is significantly improved, and wax drum filming does not occur even in printing durability tests.

Since the grafted wax is uniformly dispersed in the toner particles, the fixing temperature is uniform, the fixing properties are good, and the offset resistance is excellent. Furthermore, the colorant, charge control agent, etc. improve the dispersibility, thereby improving the uniformity and stability of the degree of coloring and the uniformity and stability of charging characteristics. Furthermore, since the wax is not released from the toner particles, the toner particles are less likely to aggregate.

Furthermore, in the manufacturing method of the present invention, since the polyolefin wax can be blended from the beginning into the polymerizable composition consisting of a polymerizable monomer, a colorant, a charge control agent, etc., the toner can be manufactured by continuous operation. Therefore, it is possible to save labor, time, energy costs, etc.

(Embodiment of the invention) The polyolefin wax (hereinafter simply referred to as wax) used in the present invention includes polyethylene, polypropylene, ethylene-propylene copolymer, polyethylene oxide,
Polypropylene oxide, ethylene/vinyl acetate copolymer,
Examples include low molecular weight polyolefins such as ethylene/acrylic acid copolymer and ethylene/acrylate copolymer. These have a weight average molecular weight of 1,000 to 40,000
0, preferably a weight average molecular weight of 2,000 to 0
00 is well used.

The amount of wax to be used is 0.5 to 20% by weight, preferably 1 to 5% by weight, based on the vinyl monomer forming the toner constant wear resin component.

The vinyl monomer used in the present invention is radically polymerizable, and the resulting polymer has the fixing properties and electrodetection properties required for toners, and can be used alone or in 2f!
Used in combination of one or more.

For example, styrene, 0-methylstyrene, m-methylstyrene, p-methylstyrene, p-ethylstyrene, 2.
4-dimethylstyrene, p-n-butylstyrene, p-
Styrene derivatives such as tert-butylstyrene, p-n-hexylstyrene%Pn-octylstyrene,
Methyl acrylate, ethyl acrylate, n-acrylate
Butyl, isobutyl acrylate, propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate,
Dimethylaminoethyl acrylate, diethylaminoethyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate,
Isobutyl methacrylate, n-octyl methacrylate,
Acrylic acid or methacrylic acid derivatives such as dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate, vinyl such as vinyl formate, vinyl acetate, vinyl propionate, etc. Esters, nitrile compounds such as acrylonitrile, methacrylonitrile, vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, vinyl-n-butyl ether, vinyl phenyl ether, vinyl cyclohexyl ether; vinyl methyl ketone, vinyl hexyl ketone , vinyl ketones such as methyl isopropenyl ketone
Examples include N-vinyl compounds such as N-vinylpyrrole, N-vinylcarbazole, N-vinylindole, and N-vinylpyrrolidone; vinyl chloride; and the like.

Furthermore, during thermometric polymerization, polyfunctional monomers such as divinylbenzene, divinyl ether, divinyl sulfone, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, trimethylolpropane, and triacrylate are added to the above vinyl monomers. It can be used by adding it to a polymer. The amount of the polyfunctional monomer added is 0.05 to 20% by weight, preferably 0.1 to 5% by weight based on the vinyl monomer.
A weight percent range is selected.

Polymerization initiators include those soluble in the monomer, such as azo compounds such as azobisisobutyronitrile, and peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, benzoyl peroxide, and lauroyl peroxide. used.

The amount of these radical polymerization initiators to be blended may be a so-called catalytic amount, and is generally preferably used in an amount of 0.1 to 10% by weight based on the monomer.

The following colorants are used:

Black pigments carbon black, acetylene black, lamp black, aniline black, black iron oxide.

Yellow pigment yellow lead, zinc yellow, cadmium yellow, yellow iron oxide, mineral leufast yellow, nickel titanium yellow, nabels yellow, naphthol yellow S, banza yellow G, benzidine yellow GR, quinoline yellow lake, permanent yellow NCC, tartrazine rake.

Orange pigment red yellow lead, molybdenum orange, permanent orange GTR, pyrazolo orange, palkan orange, indasthrene blueluant orange RK, benzidine orange G1 indasthrene blueluant orange GK.

Red pigment red pigment Red Garla, Cadmium Red, Red Lead, Mercury Cadmium Sulfide, Permanent Red 4R, Lysole Red, Pyrazolone Red, Watching Red Calcium Salt, Lake Red D1 Brilliant Carmine 6B, Eosin Lake, Rhodamine Lake B, Alizarin Lake, Brilliant Carmine 3B .

Purple pigment Manganese Purple, Fast Violet B1 Methyl Violet Lake.

Blue pigments navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine, fast sky blue, industhrene blue BC.

Green pigment chrome green, chromium oxide, pigment green B,
Malachite Green Lake, Fanal Yellow Green G.

white pigment Zinc white, titanium oxide, antimony white, zinc sulfide.

Extender pigments Palite powder, barium carbonate, clay, silica, white carbon, talc, alumina white.

These colorants may be blended in the amount contained in the toner resin, and are generally used in an amount of 1 to 30% by weight, particularly 3 to 20% by weight, based on the monomer.

Further, in the present invention, when producing a so-called -component type developing toner, a magnetic material can be used as a colorant.

Such magnetic material pigments include, for example, triiron tetroxide (Fe5O4), iron sesquioxide (y-Fe20.), zinc iron oxide (ZnFe, On), iron yttrium oxide (Y3
FesO+t), cadmium oxide (CdFe204)
, iron gadolinium oxide (Gd3Fe50.z), iron copper oxide (CuFe, 04), iron oxide complex (PbFe+, O+
e), neodymium iron oxide (NdFe0s), barium iron oxide (BaFe+zO+s), iron manganese oxide (Mn
FetO4), lanthanum iron oxide (LaFeO,),
Iron powder (Fe), cobalt powder (Go), nickel powder (N
i) and the like are known, but any fine powder of these known magnetic materials can be used in the present invention.

Such magnetic materials are generally used in proportions of 5 to 300% by weight, in particular 10 to 250% by weight, based on monomer.

As the charge control agent used in the present invention, any charge control agent conventionally used for toners can be used. Examples of charge control agents include oil-soluble dyes such as nigrosine dye, oil black, and spirone black, naphthenic acid, salicylic acid, octylic acid, higher fatty acids, and resin acids such as manganese, iron, cobalt, lead, zinc, and cerium chloride. Examples include metal soaps which are metal salts such as calcium and nickel, metal-containing azo dyes, pyrimidine compounds, and metal chelates of alkylsalicylic acids. A typical example of a positive charge control agent is an oil-soluble dye, and a typical example of a negative charge control agent is a metal-containing complex dye.

Although these charge control agents differ depending on the type, the content of these charge control agents is 0.5 to 5% by weight, particularly 1 to 2% by weight, based on the toner.
It is better to use it in

Fine powder of a water-soluble polymer compound and/or a poorly water-soluble inorganic compound is used as a dispersion stabilizer during suspension polymerization.

Water-soluble polymer compounds include gelatin, starch, hydroxyethyl cellulose, carboxymethyl cellulose,
polyvinylpyrrolidone, polyvinyl alkyl ether,
Examples of the poorly water-soluble inorganic compound include barium sulfate, calcium sulfate, barium carbonate, calcium carbonate, magnesium carbonate, calcium phosphate, talc, clay, silicic acid, diatomaceous earth, and the like. These are 0.1 to 51% by weight of water, preferably 0.5
~31% by weight is used.

Graftability of Wax As previously pointed out, in the present invention, the graft modification treatment of wax involves adding a vinyl monomer to wax in the coexistence of at least one component selected from the group consisting of a coloring agent and a charge control agent. Graft polymerization is carried out using bulk polymerization without using a solvent such as toluene. In the present invention, the polymerization product produced by the above-mentioned graft polymerization and the remaining toner material, a vinyl monomer, a colorant,
Toner particles are directly obtained by preparing a charge control agent and carrying out suspension polymerization using this as a polymerizable composition for toner. Therefore, considering the prevention of disproportionality of the oil droplet particles due to the increase in viscosity of the polymerizable composition during the formation of suspended oil droplets and the fixability of the generated toner particles, the polymer generated by the above graft polymerization reaction is It is preferable that the polymer has a low molecular weight, and the reaction is preferably carried out at a temperature that shortens the half-life of the initiator. Specifically, the weight ratio of the vinyl polymer and the wax is 10% by weight. :1 to 100:1,
The reaction can be carried out using a polymerization initiator such as a peroxide type or azo type, and setting the reaction temperature to 80 to 140°C and the reaction time to about 30 to 180 minutes.

Also, colorants used during wax grafting,
The amount of the charge control agent to be used in the wax varies depending on the type, property, grafting conditions, etc., but is usually used in an amount of 20 to 500 parts by weight per 100 parts by weight of the wax. The amount may be an amount that provides good binding and dispersibility of the wax grafted product to the toner resin.

After the polymerization reaction is completed, when the mixture is cooled with stirring, the grafted wax is integrated (grafted or firmly adsorbed) with the grafted product such as the colorant or charge control agent and precipitates in the form of fine particles.

Further, in the above reaction, the grafted colorant may be produced first, and then the wax and, if necessary, the charge control agent may be added to produce the grafted wax.

Suspension polymerization A vinyl monomer, a polymerization initiator and, if necessary, a charge control agent, are added to the polymerization product containing the grafted wax precipitated together with the grafted product such as the colorant and charge control agent.
A coloring agent is blended to prepare a polymerizable composition for toner. Then, this polymerizable composition for toner is immersed in an aqueous phase containing a dispersion stabilizer to form suspended oil droplets.

In this oil droplet formation step, the above-mentioned dispersion stabilizer is used, but poorly water-soluble inorganic compounds are preferably used because they can be efficiently removed from the polymerized product after polymerization. In addition, when using poorly water-soluble inorganic compounds,
Dispersion stability becomes more favorable when a small amount of surfactant is used in combination. Examples of these surfactants include fatty acid salts such as sodium oleate, higher alcohol sulfate ester salts such as sodium lauryl sulfate, and alkylaryl sulfonates such as sodium dodecylbenzenesulfonate. These surfactants are preferably used in an amount of 0.5% by weight or less, particularly 0.1% by weight or less, based on the poorly water-soluble inorganic compound.

A high-speed shearing stirrer such as a homomixer or a homogenizer is used as a mixer and stirrer used for suspension and dispersion. Generally, the stirring speed is 50θ0 to 30000 rpm.
The granulation time is preferably carried out at a rotational speed of about 1 minute to 1 hour, although there is no particular restriction. In this way, the particle size of the produced oil droplets is adjusted to 5 to 20 μm, particularly 6 to 15 μm.

Next, a radical polymerization reaction is carried out in the state in which the above-mentioned oil droplets are formed. The polymerization initiator is 2,2゛-azobis(2,4
General polymerization initiators such as azo compounds such as -dimethylvaleronitrile), 2,2°-azobisisobutyronitrile, and peroxides such as cumene hydroperoxide, t-butyl hydroperoxide, and benzoyl peroxide are used. used. These are used singly or as a mixture of two or more, and the amount per vinyl monomer (further added after grafting) is 0.
．． 5 to 20% by weight, especially 2 to 15% by weight are preferably used.

The polymerization conditions can be determined as appropriate, but - it is sufficient to go fishing on a boat, introduce nitrogen gas, set the polymerization temperature at 50 to 90° C. with gentle stirring, and carry out the reaction for about 3 to 12 hours. After the polymerization reaction is completed, the produced particles are filtered, washed with water or a suitable solvent as necessary, and dried to obtain toner particles. The toner particles are optionally sprinkled with particles of external additives known in the art, such as carbon black, hydrophobic silica, aluminum oxide, stearic acid, various polymer fine powders, etc., to form the final toner composition.

Hereinafter, the present invention will be explained in more detail with reference to Examples and Comparative Examples.

(Example 1) 5 parts by weight of carbon black, 30 parts by weight of styrene monomer, 2 parts by weight of AIBN O, (manufactured by Mitsubishi Chemical Corporation = MA-
100 (Product Name)) Charge Control Agent, Oil Black HBB
(manufactured by Orient Chemical Co., Ltd., trade name) 0.1 part by weight,
Carbon black grafting treatment was performed at 80° C. for 1 hour under a nitrogen stream.

Adding 2 parts by weight of low molecular weight polypropylene: Viscol 550P (manufactured by Sanyo Kasei Co., Ltd.: trade name) and 0.2 parts by weight of a peroxide-based initiator lauroyl peroxide to the polymerizable composition containing the grafted carbon black, After further reacting at 85° C. for 1 hour, the mixture was rapidly cooled to precipitate the grafted wax in the form of fine particles.

(At this point, the polymerization rate of the system was 40%.) The above polymerizable composition was mixed with Spiron Black TRH (manufactured by Hodogaya Chemical Co., Ltd.).
Product name) 1 part by weight, 0.7 parts by weight of divinylbenzene, 50 parts by weight of styrene monomer, and 20 parts by weight of 2-ethylhexyl methacrylate were added, and after sufficiently dispersing in a ball mill, 5 parts by weight of DVN was added to the polymerization initiator. was added to prepare a polymerizable composition for toner.

The above polymerizable composition was added to an aqueous phase consisting of 6 parts by weight of tricalcium phosphate, 0.03 parts by weight of sodium dodecylbenzenesulfonate, and 400 parts by weight of water, and TK and Homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) were added. After suspension at 10,000 rpm for 15 minutes, polymerization was performed at 80° C. for 8 hours. The obtained particles were washed with 0.3N HCI to remove calcium phosphate, and after washing with water three times and turning over, the particles were dried under reduced pressure to obtain a toner having an average particle size of lO1θμm.

Next, 0.2 parts by weight of hydrophobic silica was mixed with 100 parts by weight of the obtained toner to prepare a toner composition, and a ferrite carrier having an average particle size of 90 μm and a toner concentration of 4.0
%, and a printing durability test of 20,000 copies was conducted using an electrophotographic copying machine DC-1205 (manufactured by Sanda Kogyo Co., Ltd., trade name). Then, the solid image density (1, D), fog density (F, D), and resolution (lines/mm) of the obtained image were measured.

In addition, initial (1-1000 pieces) and later (15,000-
(20,000 sheets), the fixability (%) and offset occurrence temperature (1) were determined. Furthermore, contamination of the photoreceptor and fixing roller after printing was also considered.

The fixability and offset occurrence temperature were determined by the following methods.

Electronic copying machine, D -1205 modified machine (heated pressure roll fixing method) setting temperature of heating roller from 100℃ to 2.5℃
Then pass the transfer paper on which the toner image has been formed and fix it. Press the adhesive tape against the formed fixed image and then peel it off. Measure it with a reflection densitometer (manufactured by Tokyo Juishoku), find the temperature that becomes 90%, find the minimum fixing temperature, and then continuously pass the paper to determine the force with which the light toner image adheres to the subsequent transfer paper. The temperature at which high temperature offset occurs was determined.

The results are shown in Table 1 below.

(Example 2) 1 part by weight of Subiron Black TRH (Hodogaya Chemical Co., Ltd., trade name) as a charge control agent, 2 parts by weight of low molecular weight polypropylene viscoel 550P (manufactured by Sanyo Chemical Co., Ltd., trade name), and peroxide 0.2 parts by weight of benzoyl, 2 parts by weight of styrene monomer
0 parts by weight was prepared using a ball mill, and a polymerization reaction was carried out at 95° C. for 1 hour. (The polymerization rate at this point was 15%.

) 35.3 parts by weight of a polymerizable composition containing grafted carbon black produced in the same manner as in Example 1 was added to the above composition, and 0.7 parts by weight of divinylbenzene and 30 parts by weight of 2-ethylhexyl methacrylate were added to the above composition. After 20 parts by weight of styrene monomer were mixed and sufficiently dispersed in a ball mill, 5 parts by weight of ADVN was added to prepare a polymerizable composition for toner.

Suspension polymerization was carried out in the same manner as in Example 1 to obtain an average particle size of 10 μm.
toner particles were obtained. Next, various tests were conducted in the same manner. The results are shown in Table 1 below.

(Example 3) 2 parts by weight of Viscol 550P, 0.2 parts by weight of Spiron black TRHI, and 0.2 parts by weight of lauroyl peroxide were added to a polymerizable composition containing grafted carbon black prepared by the same method as in Example 1. After polymerization was carried out at 85° C. for 1 hour, the mixture was rapidly cooled to precipitate the grafted wax in the form of fine particles. (At this point, the polymerization rate of the system was 40%.) A toner was synthesized by suspension polymerization in the same manner as in Example 1, and toner particles with an average particle size of 11 μm were obtained. Various tests were conducted using the following methods. The results are shown in Table-1.

(Example 4) Carbon black (M^-100) 5 parts Spiron black TRH (manufactured by Hodogaya Chemical Co., Ltd., trade name) as a charge control agent 1 part by weight, low molecular weight polypropylene, Viscoel 550P (manufactured by Sanyo Chemical Co., Ltd., Product name) 2 parts by weight, AIB
15 parts by weight of N 2 O and 40 parts by weight of styrene monomer were prepared, polymerized at 85° C. for 1.5 hours, and rapidly cooled to precipitate a grafted wax. (At this point, the polymerization rate of the system is 35
%Met. ) In addition to the above polymerization product, 40 parts by weight of styrene monomer and 20 parts by weight of 2-ethylhexyl methacrylate were added.
After thoroughly dispersing the mixture, 5 parts by weight of a polymerization initiator ADVN was added to prepare a polymerizable composition for toner.

Hereinafter, suspension polymerization was carried out in the same manner as in Example 1, and the average particle size was 10.
Toner particles of μm were obtained.

(Comparative Example 1) Low molecular weight polypropylene biscol 550P, 2[i
0.2 parts by weight of benzoyl peroxide and 20 parts by weight of styrene monomer were prepared in a ball mill and polymerized at 95° C. for 1 hour to obtain a grafted wax. This was rapidly cooled to precipitate the grafted wax.

Thereafter, suspension polymerization was carried out in the same manner as in Example 1 to produce toner particles having an average particle size of 10 μm. Then, various tests were conducted in the same manner as in Example 1. The results are shown in Table-1.

Table 1 shows that the toner particles obtained by the method of the present invention can maintain high density for a long period of time without causing fogging, and can form clear images with high resolution. Can be expanded. Also,
It can be seen that even in the 20,000-sheet printing test, the photosensitive drum fixing roller did not get dirty and the wax was retained in the toner even during the printing.

(Effects of the Invention) The toner obtained by the production method of the present invention is produced by graft polymerizing a vinyl monomer onto wax in the presence of at least one component selected from the group of colorants and charge control agents. Since graft polymerization occurs, along with the graft polymerization of the wax, graft polymerization also occurs on the surface of the particles of the colorant, charge control agent, etc. dispersed in this system, and the polyfunctional groups of the colorant, charge control agent, etc.
A grafted wax is further grafted onto the grafted product of fine particles such as a charge control agent or is strongly adsorbed.

When the graft-modified product obtained in this way is added to a polymerizable toner composition mainly composed of vinyl monomers and dissolved or dispersed, the grafted wax is dispersed along with the dispersion of colorants, charge control agents, etc. It can be uniformly dissolved or dispersed in the polymerizable toner composition. Then, this graft-modified composition-added polymerizable toner composition is suspended in an aqueous phase containing a suspension stabilizer, and the particle size is set to a desired particle size. When suspension polymerization is carried out, spherical polymer particles having the desired particle size are obtained. is obtained.

The colorant, charge control agent, grafted wax, other modifiers, etc. within the particles are integrally combined with the toner resin (fixing resin), and each particle has a uniform composition.

The grafted wax in the toner particles is combined with the colorant, charge control agent, etc., so the binding property with the fixing resin is significantly improved and strong, and the wax does not separate from the toner. Printing durability is significantly improved, and wax drum filming does not occur even in printing durability tests.

Since the grafted wax is uniformly dispersed in the toner particles, the fixing temperature is uniform, the fixing performance is good, and the offset resistance is excellent. Furthermore, the coloring agent, charge control agent, etc. improve the dispersibility, thereby improving the uniformity of the degree of coloring, the fixing property, the uniformity of the charging characteristics, and the stability. In addition, since no wax is released from the toner particles, the toner particles are less likely to aggregate, so there is no need to use a lubricant such as hydrophobic silica fine powder to improve fluidity, or even if it is used, it is minimal. The quantity will be sufficient.

It is possible to obtain a toner having excellent effects such as.

Further, according to the manufacturing method of the present invention, the steps can be shortened compared to conventionally known methods, and labor, time, energy, and expenses can be saved.

Claims (1)

[Claims] (1) A polyolefin wax is graft-modified with a vinyl monomer in the coexistence of at least one component selected from the group consisting of a colorant and a charge control agent, and the graft-modified product is transformed into a vinyl monomer. 1. A method for producing a toner for developing an electrostatic image, the method comprising adding the toner to a polymerizable toner composition mainly containing a toner and carrying out suspension polymerization.