JPH0731418B2 - Method for producing polymerized toner - Google Patents

Description

The present invention relates to a method for producing a polymerized toner produced by a suspension polymerization method.

[Prior Art] Conventionally, a toner used in a dry image forming method such as an electrophotographic method, an electrostatic printing method, and an electrostatic recording method is generally prepared by melt-mixing a colorant and other additives in a thermoplastic resin, After being uniformly dispersed, it is pulverized by a fine pulverizer and classified by a classifier so as to have a desired particle size. The resulting toner is quite good, but has potential problems due to the grinding process. That is, the toner obtained using the crushing method must have brittleness so that the material is crushed to some extent. However, if the toner is too brittle, it will be too finely pulverized, and it will be necessary to perform fine powder cutting in order to obtain a toner having an appropriate particle size distribution, which results in an increase in cost. Further, in the developing device of the copying machine, it is sometimes further pulverized. When a material having a low melting point is used to improve the heat fixing property or a material having a pressure fixing property is used,
In some cases, a fusion phenomenon occurs in the crushing device or the classifying device, and continuous production cannot be performed.

Therefore, as one means for overcoming the problems of the pulverization method, a polymerized toner produced from a polymerizable monomer by a suspension polymerization method has been proposed.

In a conventional general suspension polymerization method, a monomer composition having at least a colorant and a polymerizable monomer is granulated into a toner particle size in an aqueous medium, and a polymerization initiator or a new polymerization agent added in advance is granulated. The polymerizable monomer is polymerized by radicals generated when the polymerization initiator added to is decomposed by heat to form a polymer, thereby producing a polymerized toner. That is, since this method does not include a crushing step, the polymerized toner does not need to be brittle and has a spherical shape, so that it has excellent fluidity and uniform triboelectricity.

In recent years, improvements in image quality of copied images, speeding up of copying machines, and / or energy saving have been aimed at, and the development characteristics of toner have been further improved, and blocking resistance, fluidity, and abrasion resistance have not been lowered, and more A toner that can form a good fixed image by low-temperature fixing and / or low-pressure fixing is desired. For these purposes, a large amount of a low softening point compound such as a solid paraffin wax or a low molecular weight polyolefin having a shape-retaining property at room temperature is added to the monomer composition to produce a larger amount than a conventional polymerized toner. Attempts have been made to produce polymerized toners containing a low softening point compound in the following. Generally, these low softening point compounds are
The affinity with carbon black or magnetic powder, which is a colorant, is poor, and only the colorant separates in the process of producing polymerized toner,
Even if it is not obtained as a toner, or even if it is obtained as a toner, the content of the colorant is lowered, and there has been a problem that a sufficient image density cannot be obtained.

[Problems to be Solved by the Invention] The present invention aims to improve the above-mentioned problems of the prior art. That is, it is an object of the present invention to provide a method for producing a polymerized toner containing a large amount of a low softening point compound and having improved dispersibility of a colorant.

[Means and Actions for Solving Problems] Specifically, the present invention provides a polymerizable monomer containing styrene 10
0 parts by weight, colorant, polar polymer or cyclized rubber, and the following formula [In the formula, R and R'represent a hydrocarbon group, and n represents an integer. ] Polyamide wax with a softening point of 40-130 ℃
A monomer composition containing at least 3,000 parts by weight is heated and mixed at a temperature higher than the softening point of the polyamide wax, and the mixed monomer composition is dispersed in a warmed aqueous medium for granulation. Then, the present invention relates to a method for producing a polymerized toner, wherein polymerized toner particles are produced by polymerizing the polymerizable monomer in the granulated monomer composition.

The present invention is characterized in that, instead of the paraffin wax and the low-molecular weight polyethylene wax which have been conventionally used as the low softening point compound, a polyamide wax having a positive polarity rather than these is used. In general, paraffin wax and low molecular weight polyethylene wax have weak polarities and have poor affinity with colorants such as carbon black and magnetic powder, which have relatively large polarities, and the colorants in the monomer composition are not uniformly dispersed. Alternatively, the colorant is liberated in water during the suspension polymerization process, and various properties as a toner cannot be exhibited. In the present invention, by using a monomer composition composed of a polymerizable monomer, a colorant and a polyamide-based low softening point compound, a large amount of the low softening point compound is contained in a state in which the dispersibility of the colorant is good. A polymerized toner was obtained.

The polyamide-based low softening point compound in the present invention has, for example, a general structural formula (R and R'are hydrocarbons), and the ring and ball method (JIS K 253
1)) softening point 40 ~ 130 ℃, preferably 50 ~
It is 120 ℃. If the softening point is less than 40 ° C, the blocking resistance of the toner is insufficient, and if it exceeds 130 ° C, the effect of lowering the fixing temperature is small. Examples of the polyamide-based low softening point compound include, for example, Diamond KH, Diamond H, Amide AP-1, Diamond 200, Diamond O, Diamond O-200, Diamond L-200,
Diamond Mid Y, Diamond Mid KP, Diamond Mid KN, Methylol Amide, Clover Ace KN, Sripack O
(Nippon Kasei Co., Ltd.), Sunmide 550, Sunmide HT-85, Sunmide HT-120, Sunmide HT-100
H, Sunmide SNT-2, Sunmide # 55, Sunmide #
550H, Sun Myde # 550D, Sun Myde 569, Sun Myde 6
11DK-1, Sunmide # 578K, Sunmide # 579H, Sunmide # 611H, Sunmide # 615A, Wax type polyamide HT-W-70B, FED-4A, FMD-01, FMD-03 (above, Sanwa Chemical Industry Co., Ltd.) ), Versamide 335, Versamide 930, Versamide 940, Versamide 711, Versamide 7
56, DPX802 (above, manufactured by Henkel Hakusui Co., Ltd.) and the like, but not limited thereto. Further, these may be mixed and used. When a low softening point compound having a softening point of 100 ° C. or higher is used, it is preferable to carry out dispersion granulation under pressure with the liquid temperature of the aqueous medium being 100 ° C. or higher.

The above-mentioned low softening point compound is a fixing temperature of the polymerized toner and / or
Alternatively, in order to lower the fixing pressure, 50 to 3,000 parts by weight are mixed with 100 parts by weight of the polymerizable monomer. Especially 70-1,000
It is preferably mixed in parts by weight. If it is less than 50 parts by weight, it is insufficient to lower the fixing temperature or fixing pressure of the fixing roller, and if it exceeds 3,000 parts by weight, the blocking resistance and durability tend to deteriorate.

The polymerizable monomer applicable to form the polymerized toner of the present invention is a monomer having a CH ₂ ═C <group as a reactive group, and is styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene. , P-methoxystyrene,
p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene , Pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene and its derivatives; vinyl esters such as vinyl acetate, vinyl propionate and vinyl benzoate. Acrylic acid,
Methacrylic acid, maleic acid, maleic acid half ester; methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, Α-Methylene aliphatic monocarboxylic acid esters such as stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate; methyl acrylate, ethyl acrylate, n-butyl acrylate, isobutyl acrylate, acrylic Propyl acrylate, n-octyl acrylate, dedosyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, phenyl acrylate and other acrylates Ters; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, methyl isopropenyl ketone; N-vinyl pyrrole, N-vinyl carbazole, N-vinyl indole , N-vinyl compounds such as N-vinylpyrrolidone; vinylnaphthalenes; monomers having a reactive double bond such as vinyl groups such as acrylic acid or methacrylic acid derivatives such as acrylonitrile, methacrylonitrile and acrylamide. There is. These may be used alone or in combination of two or more. You may use a crosslinking agent as needed. Examples of the crosslinking agent include divinylbenzene, divinylnaphthalene, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate and the like. The addition amount of the crosslinking agent is usually 0.1 to 5 parts by weight based on 100 parts by weight of the polymerizable monomer. Also,
A small amount of a polymer of these polymerizable monomers may be added to the monomer composition. Among the above-mentioned monomers, styrene, styrene having a substituent such as an alkyl group, or a mixed monomer of styrene and another monomer is preferable in view of developability and durability.

Further, a preferable polymerized toner can be obtained by adding a polar polymer having a polar group, a polar copolymer or a cyclized rubber as an additive during the polymerization of the monomer to polymerize the polymerizable monomer. Polar polymer, polar copolymer or cyclized rubber,
0.5 to 50 parts by weight, preferably 1 to 40 parts by weight is added to 100 parts by weight of the polymerizable monomer. If it is less than 0.5% by weight, it is difficult to obtain a sufficient pseudocapsule structure.
If the amount is more than parts by weight, the amount of the polymerizable monomer becomes insufficient and the properties of the polymerized toner tend to deteriorate. Polymerization is carried out by suspending a polar monomer, a polar copolymer, or a polymerizable monomer composition containing a cyclized rubber in an aqueous phase of an aqueous medium in which a dispersant having an opposite charge to the polar polymer is dispersed. Preferably. That is, the cationic or anionic polymer, the cationic or anionic copolymer, or the anionic cyclized rubber contained in the polymerizable monomer composition is a reversely charged anion dispersed in an aqueous medium. Of electrostatic or cationic dispersant electrostatically attracts the particle surface of the toner, and the dispersant covers the particle surface to prevent unification of the particles and stabilize them, as well as added polar polymer and polar copolymer. Alternatively, since the cyclized rubber gathers on the surface layer of the particles that serve as the toner, it becomes a kind of shell-like form, and the obtained particles become pseudo capsules. The relatively high molecular weight polar polymer, polar copolymer or cyclized rubber gathered in the surface layer of the particle encloses a large amount of the low softening point compound inside the toner particle, so that the polymerized toner particle of the present invention has blocking properties. Imparts excellent developability and abrasion resistance. The polar polymers (including polar copolymers and cyclized rubbers) and reversely-charged dispersants that can be used in the present invention are exemplified below. The weight average molecular weight of the polar polymer measured by GPC is 5,000.
Those having a molecular weight of up to 500,000 dissolve well in the polymerizable monomer and have durability, and thus are preferably used.

(I) As the cationic polymer, a polymer of a nitrogen-containing monomer such as dimethylaminoethyl methacrylate or diethylaminoethyl acrylate, a copolymer of styrene and the nitrogen-containing monomer or styrene, an unsaturated carboxylic acid ester, etc. And the nitrogen-containing monomer.

(Ii) Examples of anionic polymers include nitrile monomers such as acrylonitrile, halogen-containing monomers such as vinyl chloride, unsaturated carboxylic acids such as acrylic acid, unsaturated dibasic acids, and unsaturated dibasic acids. There are anhydride polymers or copolymers of styrene and said monomers.

As the dispersant, an inorganic fine powder which has the ability to disperse and stabilize the monomer composition particles in an aqueous medium and is sparingly soluble in water is preferable. The amount of dispersant added to the aqueous medium is based on water.
It is preferable to add 0.1 to 50% by weight (preferably 1 to 20% by weight).

(Iii) Examples of anionic dispersants include Aerosil # 200,
There are colloidal silica such as # 300 (manufactured by Nippon Aerosil Co., Ltd.).

(Iv) Examples of the cationic dispersant include aluminum oxide, magnesium hydroxide, and fine powder of hydrophilic positively charged silica such as aminoalkyl-modified colloidal silica treated with a coupling agent.

Instead of the above polar polymer or copolymer, a cyclized rubber having anionic property may be used.

To produce a magnetically polymerized toner, magnetic particles are added to the monomer composition. In this case, the magnetic particles also serve as a coloring agent. The magnetic particles that can be used in the present invention include substances that are magnetized when placed in a magnetic field, such as iron,
Examples include powders of ferromagnetic metals such as cobalt and nickel, and powders of alloys and compounds such as magnetite, hematite and ferrite. Magnetic fine particles having a particle size of 0.05 to 5 μm, preferably 0.1 to 1 μm are used. The content of the magnetic particles is 10 to 60% by weight, preferably 20 to 50% by weight, based on the weight of the toner. Further, these magnetic fine particles may be treated with a treating agent such as a silane coupling agent or a titanium coupling agent, or an appropriate reactive resin. In this case, depending on the surface area of the magnetic fine particles and the density of the hydroxyl groups existing on the surface, it is 5% by weight or less (preferably 0.1% or less).
With a treatment amount of 1 to 3% by weight, sufficient dispersibility in the polymerizable monomer and the low softening point compound is obtained, and the physical properties of the toner are not adversely affected. The polymerized toner contains a colorant, and as the colorant, conventionally known dyes, carbon black, and pigments such as grafted carbon black obtained by coating the surface of carbon black with a resin can be used. . The colorant is contained in an amount of 0.5 to 30% by weight based on the polymer and the low softening point compound. A charge control agent and a fluidity modifier may be added (internally added) to the toner, if necessary. The charge control agent and the fluidity modifier may be used as a mixture (external addition) with toner particles. Examples of the charge control agent include metal complexes of organic compounds having a carboxyl group or a nitrogen-containing group, metal-containing dyes, nigrosine and the like. Examples of fluidity modifiers and auxiliary agents for cleaning the surface of the latent image bearing member (photoreceptor) include colloidal silica and fatty acid metal salts.
Further, for the purpose of increasing the amount, a filler such as calcium carbonate or fine powder silica may be blended in the toner in an amount of 0.5 to 20% by weight. Further, in order to prevent the toner particles from coagulating with each other and improve the fluidity, a fluidity improver such as Teflon (registered trademark) fine powder or zinc stearate powder may be added. When a low softening point compound such as a low molecular weight hydrocarbon compound (for example, a weight average molecular weight of 500 to 5,000) or a carnauba wax that improves releasability at the time of heat roll fixing is used as the low softening point compound, for example, the hydrocarbon compound is hydrophobic and low. Since it has a molecular weight, it is less likely to mix with the polymer produced by the polymerization, and is less likely to be exposed on the particle surface as compared with a polar polymer, a polar copolymer or a cyclized rubber, and will be pushed into the polymerized toner. As a result, even if it contains a large amount of the low softening point compound, it is excellent in durability and blocking resistance because it is encapsulated. Then, the toner comes out of the inside at the time of fixing, and the fixability and offset property are remarkably improved. In other words, it serves as an offset agent and a fixing agent.

When the polymerized toner of the present invention is applied to a two-component developer, it can be applied at a compounding ratio of a normal toner and a carrier, and for example, 1 to 500 parts by weight of the carrier is mixed with 1 part by weight of the toner. .

The suspension method is a colorant (including a magnetic material in the present invention), 50 to 3,000 parts by weight of the low-softening point compound and 100 parts by weight of the polymerizable monomer are uniformly dissolved, Alternatively, the dispersed monomer composition is used in an aqueous medium containing 0.1 to 50% by weight of a suspension stabilizer (for example, a sparingly soluble inorganic dispersant) (for example, 5 ° C or higher, preferably 10 ° C or higher than the polymerization temperature).
It is dispersed in an ordinary stirrer, homomixer, homogenizer, etc. Preferably the agitating speed, time and aqueous medium so that the particles of the melted or softened monomer composition have the desired toner particle size, generally less than 30 μm (eg volume average particle size 0.1-20 μm). Adjust the temperature. Then, the liquid temperature of the aqueous medium is lowered to the polymerization temperature while stirring is carried out to the extent that the settling of the particles is prevented so that the state is almost maintained by the action of the dispersion stabilizer. The polymerization temperature is
50 ° C or higher, preferably 55 to 80 ° C, particularly preferably 60 to 75
The temperature is set to ° C, and a substantially water-insoluble polymerization initiator is added with stirring to carry out polymerization. After the completion of the reaction, the produced toner particles are collected by an appropriate method such as washing, removal of the dispersion stabilizer, filtration, decantation, centrifugation and the like, and dried to obtain the polymerized toner of the present invention. In the suspension polymerization method, usually 200 to 3,000 parts by weight of water is used as an aqueous dispersion medium with respect to 100 parts by weight of the polymerizable monomer and the low softening point compound.

Also suitable stabilizers such as polyvinyl alcohol,
Gelatin, methyl cellulose, methyl hydropropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and salts thereof, starch, gum alginate, zein, casein,
Any one or a mixture of tricalcium phosphate, talc, barium sulfate, bentonite, aluminum hydroxide, ferric hydroxide, titanium hydroxide, thorium hydroxide and the like is used as an aqueous medium to adversely affect the production method of the present invention. You may use the thing contained to the extent that there is not.

Further, in order to uniformly disperse the inorganic dispersion stabilizer, a surfactant may be used to such an extent that the production method of the present invention is not adversely affected. This is to accelerate the intended action of the above dispersion stabilizer, and specific examples thereof include sodium dodecylbenzenesulfonate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, and allyl-alkyl-polyether. Sodium sulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, 3,3-disulfone diphenylurea-4,4-diazo-bis-amino- 8-naphthol-6-
Sodium sulfonate, ortho-carboxybenzene-
Azo-dimethylaniline, 2,2,5,5-tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-disulfonic acid sodium salt, and the like can be mentioned. However, it should be noted that when a hydrophilic organic stabilizer or surfactant is used, the moisture resistance of the polymerized toner decreases.

Further, a water-soluble polymerizable monomer simultaneously undergoes emulsion polymerization in water, and since the resulting suspension polymer is contaminated with small emulsion-polymerized particles, a water-soluble polymerization inhibitor, such as a metal salt, is added. It is also possible to prevent emulsion polymerization in the aqueous phase. It is also possible to add glycerin, glycol or the like to water in order to reduce the viscosity of the aqueous medium and prevent the particles from coalescing during polymerization. Further, salts such as NaCl, KCl and Na ₂ SO ₄ may be added to the aqueous medium in order to reduce the solubility of the easily soluble polymerizable monomer in water. It is also possible to add a Bronsted acid such as hydrochloric acid to the aqueous medium in order to enhance the ionization of the polar groups of the polar polymer or cyclized rubber in the monomer composition. In particular, the addition of Bronsted acid such as hydrochloric acid to the aqueous medium is effective in further enhancing the effect of the anionic polymer, anionic copolymer or cyclized rubber.

The polymerized toner of the present invention can be applied to a known dry electrostatic image developing method. For example, two-component developing method such as cascade method, magnetic brush method, microtoning method; one-component developing method using magnetic toner such as conductive one-component developing method, insulating one-component developing method, jumping developing method; powder cloud Method and fur brush method; a non-magnetic one-component developing method in which the toner is carried on the toner carrier by electrostatic force and is transferred to the developing section for development; an electric field curtain is transferred to the developing section by the electric field curtain method and developed. It can be applied to the developing method. Although it is particularly preferably applicable to the dry developing method, it may optionally be used as a toner for the wet developing method.

[Examples] Hereinafter, the present invention will be described in detail based on Examples.

Example 1 The above components were mixed with an attritor at a temperature of 65 ° C. for 4 hours to prepare a monomer composition. Obtained monomer composition 254
Parts by weight of amino-modified silica (100 parts by weight of Aerosil 2
20 parts by weight of 00 treated with 5 parts by weight of aminopropyltriethoxysilane) and 25 parts by weight of 0.1N hydrochloric acid.
The mixture was put into an aqueous medium of 1200 parts by weight of distilled water heated to 65 ° C. while stirring with a TK homomixer, and after the addition, the mixture was stirred at 10,000 rpm for 15 minutes to carry out dispersion granulation.

After granulation, the liquid temperature was lowered to 60 ° C, and 3 parts by weight of 2,2'-azobis- (2,4-dimethylvaleronitrile) and 1.5 parts by weight of 2,2'-azobisisobutyronitrile were used as a polymerization initiator. Add to aqueous medium and stir for 30 minutes. Further, stirring was changed to paddle blade stirring, and stirring was carried out at 60 ° C. for 10 hours to complete the polymerization.

The obtained polymerized toner-containing aqueous medium is cooled and dehydrated,
Washing with sodium hydroxide solution to dissolve and remove amino-modified silica, washing with water, dehydration, and drying (if necessary, fine particles of unnecessary component particles are removed) to obtain a volume average particle diameter of 8 μm (100 μm (Measured with a Coulter counter using the aperture of No. 1) to obtain a polymerized toner. The obtained polymerized toner contained about 200 parts by weight of polyamide wax based on 100 parts by weight of polystyrene. Further, the obtained toner did not cause blocking even if left in an environment of 50 ° C. for one day. From this, it was found that the polyamide wax was encapsulated inside the polymerized toner particles.

10 parts by weight of the obtained polymerized toner, zinc stearate powder 0.
1 part by weight, hydrophobic silica (Aerosil R972, manufactured by Nippon Aerosil Co., Ltd.) 0.1 part by weight, and insulating carrier particles having an average particle size of 40 μm (formed from 75 parts by weight of iron tetraoxide and 25 parts by weight of epoxy resin) 90 parts by weight Were mixed to prepare a developer, and development was performed under the following conditions.

The developing device shown in FIG. 1 was used. The image carrier has a selenium photoreceptor, the peripheral speed of the image carrier 1 is 100 mm / sec, the maximum potential of the electrostatic charge image formed on the image carrier is +750 V, the outer diameter of the sleeve (developer carrier) 2. 20mm, and the peripheral speed is
100 mm / sec, the magnetic flux density in the vertical direction on the sleeve surface of the N and S poles of the magnet roller 3 is 1000 gauss, and the thickness of the developer layer is 20.
0 μm, the gap between the sleeve 2 and the image carrier 1 was 300 μm, the bias voltage applied to the sleeve was DC voltage component +200 V, AC voltage component was 3.0 KHz, and development was performed at 1400 Vpp. The electrostatic latent image is well developed, the developed toner image is electrostatically transferred to plain paper, and the toner image on the plain paper is fixed roller and pressure roller having a silicone rubber surface layer under pressure of 15 Kg / cm ^2. It was fixed through a heat and pressure roller fixing device (nip width 7 mm, paper traveling speed 200 mm / sec). The fixing temperature is shown in Table 1.

In the developing device of FIG. 1, the toner T having the external additive is quantitatively supplied to the lower chamber by the supply roller 8 and the elastic member 7 and mixed with the carrier to form the developer 4. A DC bias power supply 5 applies a DC bias, and an AC bias power supply 6 applies an AC bias to the sleeve 2 and the doctor blade 10 that incorporate the magnet roller 3. The developer 4 is conveyed with the rotation of the sleeve 2 in the A direction, and is used for the development of the electrostatic latent image on the image carrier 1 composed of the aluminum cylinder 11 and the selenium photoconductor 12. The developer layer regulating member 9 also serves as an outer wall of the developing device.

Comparative Example 1 Example 1 was repeated except that the wax type polyamide FMD-01 was changed to 40 parts by weight in Example 1. The results of the blocking test, the fixing temperature, the carbon dispersion ratio and the initial image density of the obtained toner are shown in Table 1.

Comparative Example 2 Example 1 was repeated except that the wax type polyamide FMD-01 was changed to 3500 parts by weight in Example 1. The obtained toner was completely blocked at 50 ° C. The fixing test and the initial image formation were not performed.

Comparative Example 3 Instead of the wax type polyamide FMD-01200 parts by weight in Example 1, paraffin wax 140 (manufactured by Nippon Seiro Co., Ltd.,
The same procedure as in Example 1 was carried out except that the softening point was 60 ° C.) and 200 parts by weight. The results of the blocking test, the fixing temperature, the carbon dispersion ratio and the initial image density of the obtained toner are shown in Table 1.

1) Leave in an oven at a temperature of 50 ° C and a humidity of 50% for 24 hours.

2) By observing the toner under a microscope.

(It is assumed that the carbon black is uniformly dispersed in the black particles.) 3) Fixing property test method Paper speed 200 mm / sec, paper temperature 25 ± 1 ° C, fixing unit pressure 15
Under the condition of Kg / cm ² , the surface temperature of the fixing roller is 50 ℃, 55 ℃,
Fix the image by changing it every 60 ° C, 65 ° C ... 5 ° C. This fixed image is tested by the following Kosri test method.

Silbon crepe paper (20 g / cm ² ) [made by Kojin Co., Ltd.] 5 sheets are piled up so that the glossy side is facing down, and the glossy side is tested by pressing it against the fixed image surface with a pressure of 40 g / cm ² and crepe paper Scrape back and forth 5 times in the direction of the fissure (indicating the direction of the fiber), the ratio of the density after the test to the density before the test [(density after rubbing /
The density before rubbing) x 100] is the fixability.

The lowest temperature at which the fixability is 80 or higher is the fix temperature.

4) Measurement value by Macbeth optical reflection densitometer.

[Advantages of the Invention] As described above, according to the present invention, the dispersibility of the colorant is improved, fixing at low temperature and / or low pressure is possible, and sufficient image density can be obtained.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing a developing device used in Examples and Comparative Examples of the present invention. 1 ... Photosensitive drum, 2 ... Sleeve, 3 ... Magnet roller, 4 ... Developer, 5,6 ... Development bias power supply, 7
...... Elastic member, 8 …… Supply roller, 9 …… Developer layer regulating member, 10 …… Doctor blade, 11 …… Aluminum cylinder, 12 …… Selenium photoreceptor.

Claims (1)

[Claims] 1. A polymerizable monomer containing styrene 100 parts by weight,
Colorant, polar polymer or cyclized rubber, and the following formula [In the formula, R and R'represent a hydrocarbon group, and n represents an integer. ] Polyamide wax with a softening point of 40-130 ℃
A monomer composition containing at least 3,000 parts by weight is heated and mixed at a temperature higher than the softening point of the polyamide wax, and the mixed monomer composition is dispersed in a warmed aqueous medium for granulation. Then, a method for producing a polymerized toner, wherein polymerized toner particles are produced by polymerizing a polymerizable monomer in the granulated monomer composition.