JPH06348055A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To provide the electrostatic charge image developing toner having excellent blocking resistance and fixability. CONSTITUTION:This electrostatic charge image developing toner is produced by a polymn. method using at least a polymerizable monomer, wax having 50 to 95 deg.C m.p., charge control agent, and arom. oxycarboxylic acid. The wax and charge control agent are incorporated with deviation in the state satisfied by equation into the extreme surface layer of the toner within 5nm from the toner surface. In the equation, A denotes the presence amt. (mass%) of the charge control agent existing in the toner surface layer; B denotes the presence amt. (mass%) of the wax existing in the toner surface layer; a denotes the amt. (mass%) of the charged charge control agent; b denotes the charged wax (mass%).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge image developing toner used in a method for developing a latent image.

[0002]

2. Description of the Related Art Generally, as a toner used in electrophotography, a colorant composed of a dye and a pigment is melt-mixed in a thermoplastic resin and uniformly dispersed, and then a desired particle diameter is obtained by a fine pulverizer and a classifier. Have been manufactured.

This production method (pulverization method) can produce a considerably excellent toner, but there is a certain limitation, that is, the selection range of the toner material. For example, the resin colorant dispersion must be sufficiently brittle to be comminuted in an economically feasible manufacturing apparatus. However, if the resin colorant dispersion is made brittle in order to meet these requirements, the particle size range of the particles formed when the particles are actually pulverized at a high speed tends to be wide, and in particular, a relatively large proportion of fine particles is The problem of being included in. Further, such a brittle material is likely to undergo further fine pulverization or pulverization when used for development such as a copying machine. Further, in this method, it is difficult to completely uniformly disperse solid fine particles such as a colorant in the resin, and depending on the degree of the dispersion, an increase in fog, a decrease in image density, and color mixing / transparency Care must be taken in dispersion as it causes defects. In addition, the exposure of the colorant on the fracture surface may cause fluctuations in the developing characteristics. Further, it is difficult to evenly disperse the charge control agent on the surface of the toner, and insufficient charging properties remain.

On the other hand, in order to overcome the problems of toner by the pulverization method, Japanese Patent Publications No. 36-10231 and 43-43.
A method for producing a toner by a suspension polymerization method has been proposed by 10799 and 51-14895. In the suspension polymerization method, a polymerizable monomer, a colorant, a polymerization initiator, and optionally a crosslinking agent, a charge control agent, and other additives are uniformly dissolved or dispersed to form a monomer composition. After that, this monomer composition is dispersed in a continuous phase containing a dispersion stabilizer, for example, an aqueous phase using a suitable stirrer, and a polymerization reaction is simultaneously carried out to obtain toner particles having a desired particle size. obtain.

Since this method does not include a pulverizing step at all, the toner does not need to be brittle, a soft material can be used, and the colorant is not exposed on the surface of the particles, resulting in charging. It is possible to allow the control agent to be evenly present on the surface, which has the advantage of having uniform triboelectric charging properties.
As a method for causing the charge control agent to be uniformly present on the toner surface, there is known a method in which the manufactured toner is subjected to mechanical treatment, thermal treatment, a spray dryer method or the like (Japanese Patent Laid-Open No. 4-21862). ). However, such a method has many manufacturing steps and is complicated,
Factors that increase costs are large, such as wasted energy and time. Further, if the toner is forcibly fixed from the outside, the problem of peeling of the charge control agent at the time of durability cannot be avoided.

Further, in recent years, it has been desired to eliminate the silicone oil for imparting releasability from the viewpoint of ecology and the like as a toner used in electrophotography. In response to this demand, a toner capable of fixing without oil application (oilless fixing) has been designed by adding a low melting point wax to a polymerizable monomer as a toner formulation to produce a polymerized toner. However, although such toners achieve oilless fixing, they do not satisfy the contradictory requirements of blocking resistance and fixing property. Further, due to this, deterioration of image quality due to durability is also a concern.

[0007]

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

That is, the object of the present invention is that the electrostatic property of the toner is good, there is no peeling of the charge control agent even when the toner is durable, there is no adverse effect such as sleeve contamination and carrier contamination, and there is no image deterioration. It is to provide a toner for image development.

A further object of the present invention is to provide an electrostatic image developing toner having good blocking resistance.

A further object of the present invention is to provide an electrostatic charge image developing toner which prevents high temperature offset without applying a releasing agent such as oil to the fixing roller.

[0011]

Means and Actions for Solving the Problems The present inventors have
As a result of diligent studies, it was found that the invention having the following constitution meets the above-mentioned requirements.

That is, the present invention is for developing an electrostatic charge image prepared by a polymerization method using at least a polymerizable monomer, a wax having a melting point of 50 to 95 ° C., a charge control agent and an aromatic oxycarboxylic acid. In the toner, the wax and the charge control agent are unevenly distributed in the toner outermost surface layer within 5 nm from the toner surface in a state satisfying the following formula.

[0013]

[Equation 2] A: Amount of charge control agent present in toner surface layer (mass%) B: Amount of wax present in toner surface layer (mass%) a; Amount of charge control agent (mass%) b; Charge wax ( Mass%) Hereinafter, the present invention will be described in detail.

In the present invention, in the aqueous dispersion medium, in the presence of a dispersion stabilizer, in the polymerizable monomer composition and / or
Alternatively, by adding an aromatic oxycarboxylic acid to the aqueous dispersion medium, the process is simple and the charge control agent can be uniformly and strongly present in the vicinity of the toner surface, toner charging characteristics, durability, blocking resistance. It is possible to obtain a toner having an excellent oilless fixing property.

The reason for this is that when an aromatic oxycarboxylic acid is added, the charge control agent which is a polar component charged in the polymerizable monomer composition is compared with that before the addition of the aromatic oxycarboxylic acid. As a result, the proportion of the toner that is evenly and abundantly present in the outermost surface layer increases, and as a result, the toner charging characteristics are improved and the durability is significantly improved. on the other hand,
The non-polar component shows a tendency opposite to the above phenomenon, and the abundance ratio in the outermost surface layer of the toner decreases. This means that the core / shell structure has become more established, which makes it possible to satisfy the contradictory requirements of anti-blocking property and fixing property, and thus very good anti-blocking property and oilless fixing property. Results are obtained. Further, due to the action and effect of these inventions, the charge control agent can be made to be surely present on the toner surface without being fixed by a mechanical treatment or the like on the surface of the core particles prepared in advance as described above. It has become possible.

The wax used in the present invention has a melting point of 50 to 95 according to the ring and ball method (JIS K2531).
What has 60 degreeC and more preferably 60-85 degreeC is desirable.

When the melting point is less than 50 ° C., it becomes difficult to retain the toner in the toner, so that the core / shell structure cannot be maintained, resulting in poor blocking resistance. If the melting point exceeds 95 ° C., the particle size of the monomer system in which the wax is dissolved sharply increases, so that the granulation property is significantly reduced. Furthermore, since the releasability is also lowered, the fixability becomes poor.

Further, in the present invention, the charge control agent and the amount of wax charged at the time of production are a and b, and the charge control and the amount of wax present in the outermost surface layer of the produced toner are A and b.
When B is set, 5.0 ≦ A / a <50 (preferably 6.0 <A / a
<20) B / b <0.75 (preferably B / b <0.30) 0.01 <a ≦ 5.0 (preferably 0.1 <a <3.
0) 5.0 ≦ b ≦ 35 (preferably 10 <b <25).

When the value of A / a is less than 5.0, the amount of the charge control agent present on the toner surface is insufficient, so that the toner charging characteristic is poor and, for example, the triboelectric charging rises slowly. When the value of A / a is 50 or more, the amount of the charge control agent present on the toner surface is too large, so that the charge control agent on the surface is easily peeled off, resulting in carrier contamination.
As a result, deterioration of durable images is promoted.

When the value of B / b is 0.75 or more, the blocking property is deteriorated because the amount of the releasing agent present on the toner surface is excessive.

When the value of a is 0.01 or less, the amount of charge control agent in the entire toner is insufficient, so that sufficient toner charging characteristics cannot be obtained, the image density is low, and toner scattering and fog occur. It will be easier. Further, the pigment dispersion also becomes poor. When the value of a exceeds 5.0, the amount of the charge control agent present on the toner surface is too large, so that the insulating property of the toner is deteriorated and the image density is greatly affected by environmental conditions.

When the value of b is less than 5.0, the effect on the fixability does not appear, that is, oilless fixing cannot be performed. If the value of b exceeds 35,
This is inconvenient because the colorant in the toner is not uniformly dispersed and granulation becomes unstable.

In the present invention, the amount of the charge control agent and the wax present on the toner surface is not particularly limited, but is preferably in the range of 1≤A≤20 and B≤10.

If the value of A is less than 1, the triboelectric charge of the toner is non-uniform and the rise is slow because the amount of charge control agent present on the toner surface is insufficient. Therefore, the initial image density tends to be low. When the value of A exceeds 20, the amount of the charge control agent present on the toner surface is too large, so that the charge control agent on the surface is easily peeled off and carrier contamination occurs, resulting in a durable image. Promote deterioration.

If the value of B exceeds 10, the amount of wax present on the toner surface is too large, resulting in blocking, the image is not good, and the sleeve or drum is contaminated, and the image becomes defective.

The content of the aromatic oxycarboxylic acid in the present invention with respect to the charge control agent is preferably 1 to 50% by mass, more preferably 10 to 40% by mass.

When the amount of the aromatic oxycarboxylic acid is less than 1% by mass with respect to the charge control agent, the charge control agent becomes unstable and decomposes during polymerization, so that sufficient toner charging characteristics cannot be obtained. When it exceeds 50% by mass, impurities become excessive, and defects such as carrier contamination and sleeve contamination occur, resulting in poor durability images.

The aromatic oxycarboxylic acid in the present invention is specifically

[0029]

[Chemical 2]

And R ₁ and R ₂ represent hydrogen, a hydrocarbon group or a hydrocarbon group containing O, N and S, and R ₁ and R ₂ may be the same or different. More preferably, an alkyl group, a carboxylic acid group, a sulfonic acid group,
It is a nitro group, a hydroxyl group, and hydrogen.

In the present invention, the aromatic oxycarboxylic acid is 50 ± 40 ° C., more preferably 50 ± 20.
By adding it in the polymerizable monomer composition at a temperature of ℃ or in the dispersion medium, it can be used without sublimation.

The "outermost surface layer" of the toner in the present invention means a range from the surface of the polymerized toner to a depth of 5 nm or less.

To measure the charge control agent and the amount of wax in the outermost surface layer, XPS (X-ray) of X-ray electron spectroscopy is used.
Photoelectron Spectroscop
y) was adopted. This method is one of the methods for qualitatively and quantitatively analyzing the constituent elements on the surface of an organic compound and the bonding state thereof, and has been widely used recently (Japanese Patent Laid-Open No. Hei 3)
-264961, and Japanese Patent Laid-Open No. 4-21862). The measurement result obtained from this XPS is the molar concentration of the constituent elements. With this data, the composition formula of the known constituent, the molar ratio of the unknown constituent is calculated by solving the molar ratios of the constituents simultaneously, and after being multiplied by the molecular weight of each constituent, by normalization, The weight percent of the component is obtained.

Among the mass percentages of the constituent elements thus obtained, the charge control agent was A and the wax was B.

The XPS used this time is ES manufactured by VG.
It is CALAB5, and the measurement conditions are as follows: X-ray source: Mg Kα _1,2 X-ray output: 8 kV, 20 mA Analyzer mode: constant analysis
zer energy (CAE) mode pass energy wide scan 50 eV narrow scan 20 eV Resolution: Ag3d _5/2 FWHM = 1.0 eV Slit: A4 Vacuum level: 1 × 10 ^-9 Torr Sampling: Fixed on the sample table with double-sided tape.

Horizontal axis correction: C _IS peak value of neutral carbon is 28
It was set to 4.6 eV.

The components of the present invention will be exemplified below. The present invention is not limited to these.

Examples of the polymerizable monomer that can be used in the above-mentioned polymerized toner include styrene-based monomers such as styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, p-methoxystyrene and p-ethylstyrene. , Methyl acrylate / ethyl acrylate / n-butyl acrylate /
Isobutyl acrylate, n-propyl acrylate, n-octyl acrylate, dodecyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, 2-chloroethyl acrylate, acrylates such as phenyl acrylate, methyl methacrylate, etc. Ethyl methacrylate, n-propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, phenyl methacrylate, dimethylaminoethyl methacrylate Examples thereof include methacrylic acid esters such as diethylaminoethyl methacrylate, and other monomers such as acrylonitrile, methacrylonitrile and acrylamide. These monomers may be used alone or in combination. Among the above monomers,
It is preferable to use styrene or a styrene derivative alone or in combination with other monomers from the viewpoint of developing characteristics and durability of the toner.

In the present invention, it is preferable to add a polymer / copolymer having a polar group as an additive to the monomer system for polymerization. Since the polar polymer / copolymer gathers in the surface layer of the toner particles, the core / shell formation is further advanced, and the toner particles are provided with excellent properties such as blocking resistance. By performing the polymerization with a low molecular weight so as to contribute to the improvement of the fixing property, it is possible to obtain a toner satisfying the contradictory requirements of further fixing property and blocking resistance. The polar polymers / copolymers that can be used in the present invention are exemplified below.

Polymers of nitrogen-containing monomers such as dimethylaminoethyl methacrylate / diethylaminoethyl methacrylate or copolymers with styrene / unsaturated carboxylic acid ester, nitrile monomers such as acrylonitrile, vinyl chloride, etc. Halogen-containing monomers, unsaturated carboxylic acids such as acrylic acid and methacrylic acid, and other unsaturated dibasic acids
Unsaturated dibasic acid anhydrides, polymers such as nitro monomers or copolymers with styrene monomers, polyesters,
Epoxy resin etc. are mentioned.

The addition amount of these polar polymers / copolymers is preferably 0.1 to 10% by mass.

As the colorant used in the present invention, known colorants can be used. For example, carbon black, iron black, C.I. I. Direct Red 1, C.I. I. Direct Red 4, C.I. I. Acid Red 1, C.I. I. Basic Red 1, C.I. I. Mordant Red 30, C.I.
I. Direct Blue 1, C.I. I. Direct Blue 2, C.I. I. Acid Blue 9, C.I. I. Acid Blue 15, C.I. I. Basic Blue 3, C.I. I. Basic Blue 5, C.I. I. Mordant Blue 7, C.I. I.
Direct Green 6, C.I. I. Basic Green 4, C.I. I. Dyes such as Basic Green 6, Yellow Lead, Cadmium Yellow, Mineral Fast Yellow, Navel Yellow, Naphthol Yellow S, Hansa Yellow G, Permanent Yellow NCG, Tartrazine Lake, Molybdenum Orange, Permanent Orange GT
R, benzidine orange G, cadmium red, permanent red 4R, watching red calcium salt,
Brilliant Carmine 3B, Fast Violet B,
There are pigments such as methyl violet lake, dark blue, cobalt blue, alkali blue lake, Victoria blue lake, quinacridone, rhodamine lake, phthalocyanine blue, fast sky blue, pigment green B, malachite green lake, and final yellow green G.

In the present invention, since the toner is obtained by the polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the colorant, and preferably the surface modification, for example, the polymerization inhibitory property is not caused. It is better to give a hydrophobic treatment with a substance. In particular, since many dyes and carbon black have a polymerization inhibitory property, caution is required when using them.
A preferred method of surface-treating a dye system is a method of polymerizing a polymerizable monomer in the presence of these dyes in advance, and the obtained colored polymer is added to the monomer system. In addition to carbon black, the carbon black may be treated with a substance that reacts with the surface functional groups of carbon black, such as polyorganosiloxane.

When the toner is used as a magnetic toner, it may contain magnetic powder. As such magnetic powder, a substance that is magnetized when placed in a magnetic field is used.
There are powders of ferromagnetic metals such as iron, cobalt and nickel, and compounds such as magnetite and ferrite. In particular, in the present invention, since a toner is obtained by using a polymerization method, it is necessary to pay attention to the polymerization inhibitory property and the water phase transfer property of the magnetic material, and preferably surface modification, for example, there is no polymerization inhibitory property. It is better to give a hydrophobic treatment with a substance.

In the present invention, for the purpose of improving the releasability at the time of heat roll fixing, waxes generally used as a releasing agent such as a hydrocarbon compound may be added to the toner. The waxes used in the present invention include paraffin / polyolefin wax and modified products thereof,
For example, in addition to oxides and graft-treated products, higher fatty acids, metal salts thereof, amide waxes, ester waxes such as tertiary or / and quaternary carbon-containing bifunctional or higher functional alcohol compounds, or A polyfunctional polyester compound obtained from a carboxylic acid compound, a polyfunctional polyester compound having a primary or / and secondary carbon and a bifunctional or higher functional alcohol compound or a carboxylic acid compound, and a tertiary or / and quaternary carbon And monofunctional ester compounds.

In the present invention, it is desirable to add a charge control agent to the toner material in order to control the chargeability of the toner. As these charge control agents, among known ones, those having almost no polymerization inhibitory property / water phase transfer property are used. For example, as positive charge control agents, nigrosine dyes, triphenylmethane dyes, quaternary ammonium salts, guanidines are used. Derivatives, imidazole derivatives, amine-based and polyamine-based compounds, and the like. As a negative charge control agent, metal-containing salicylic acid-based compounds, metal-containing monoazo-based dye compounds, urea derivatives, styrene-acrylic acid copolymers, styrene-methacryl Examples thereof include acid copolymers.

The addition amount of these charge control agents is 0.
1 to 10 mass% is preferable.

As the polymerization initiator, any suitable polymerization initiator, for example, 2,2'-azobis- (2,4-dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1 '-Azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-
Azo-based or diazo-based polymerization initiators such as 2,4-dimethylvaleronitrile and azobisisobutyronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, diisopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, etc. The peroxide-based polymerization initiator of These polymerization initiators are preferably added in an amount of 0.5 to 20% by mass of the polymerizable monomer, and may be used alone or in combination.

In the present invention, in order to control the molecular weight, known crosslinking agents and chain transfer agents may be added, and the preferable addition amount is 0.001 to 15% by mass.
Is.

As an additive for imparting various toner characteristics, from the viewpoint of durability in the toner or when added to the toner, the particle diameter is 1/5 or less of the volume average diameter of the toner particles. Is preferred. The particle size of the additive means the average particle size thereof obtained by observing the surface of the toner particles with an electron microscope. As the additives for imparting these characteristics, for example, the following ones are used.

1) Flowability-imparting agents: metal oxides (silicon oxide, aluminum oxide, titanium oxide, etc.), carbon black, carbon fluoride, etc. Those subjected to a hydrophobic treatment are more preferable.

2) Abrasive: Metal oxide (strontium titanate, cerium oxide, aluminum oxide, magnesium oxide, chromium oxide, etc.), nitride (silicon nitride, etc.), carbide (silicon carbide, etc.), metal salt (calcium sulfate, Barium sulfate, calcium carbonate, etc.).

3) Lubricants: Fluorine-based resin powder (vinylidene fluoride, polytetrafluoroethylene, etc.), fatty acid metal salts (zinc stearate, calcium stearate, etc.), etc.

4) Charge control particles: metal oxides (tin oxide, titanium oxide, zinc oxide, silicon oxide, aluminum oxide, etc.), carbon black, etc.

These additives are used in an amount of 0.1 to 10 parts by mass with respect to 100 parts by mass of toner particles, and preferably,
0.1-5 parts by mass are used. These additives may be used alone or in combination.

Any suitable stabilizer is used in the dispersion medium used in the present invention. For example, as an inorganic compound, tricalcium phosphate, magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate. -Bentonite, silica, alumina, etc. may be mentioned. As an organic compound, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, polyacrylic acid and its salt, starch and the like can be dispersed in an aqueous phase and used.
It is preferable to use 0.2 to 20 parts by mass of these stabilizers with respect to 100 parts by mass of the polymerizable monomer.

When an inorganic compound is used among these stabilizers, a commercially available product may be used as it is, but the inorganic compound may be produced in a dispersion medium in order to obtain fine particles. For example, in the case of tricalcium phosphate, it is advisable to mix the sodium phosphate aqueous solution and the calcium chloride aqueous solution under high stirring.

Further, in order to finely disperse these stabilizers, 0.001 to 0.001 to 100 parts by mass of the polymerizable monomer is used.
You may use 0.1 mass part surfactant. This is for promoting the intended action of the dispersion stabilizer, and specific examples thereof include sodium dodecylbenzene sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, and lauric acid. Examples include sodium, potassium stearate, calcium oleate, and the like.

The polymerized toner used in the present invention is obtained by the following method. That is, the release agent in the polymerizable monomer
A colorant, a charge control agent, a polymerization initiator and other additives are added, and the monomer, which has been uniformly dissolved or dispersed by a homogenizer or an ultrasonic disperser, is normally stirred in an aqueous phase containing a dispersion stabilizer. Disperse with a machine or homomixer / homogenizer. The aromatic oxycarboxylic acid is added to the monomer system and / or the aqueous phase. Preferably the monomer droplets are of the desired toner particle size, generally 3
Granulation is performed by adjusting the stirring speed and time so as to have a particle size of 0 μm or less. After that, stirring may be performed to the extent that the particle state is maintained and the particles are prevented from settling due to the action of the dispersion stabilizer. Polymerization temperature is 40 ° C or higher, generally 5
Polymerization is performed by setting the temperature at 0 to 90 ° C. In addition, the temperature may be raised in the latter half of the polymerization reaction, and further in the latter half of the reaction or the end of the reaction in order to remove unreacted polymerizable monomers and by-products that may cause odor during toner fixing. The aqueous medium may be partially distilled off later. After the reaction is completed, the produced toner particles are collected by washing and filtration and dried. In the suspension polymerization method, usually 300 parts by weight of water is added to 100 parts by weight of the monomer system.
It is preferable to use 3000 parts by weight as the dispersion medium.

The present invention will be specifically described below based on Examples and Comparative Examples, but these do not limit the present invention in any way.

[0061]

Example 1 To 710 g of ion-exchanged water, 440 g of 0.1 M Na ₃ PO ₄ aqueous solution was added, and after heating to 60 ° C., 1.0 M-C
67.7 g of aCl ₂ aqueous solution was gradually added to Ca (P
An aqueous medium containing O ₄ ) ₂ was obtained.

Styrene 180 g n-Butyl acrylate 20 g C.I. I. Pigment Blue 15: 3 15 g Styrene-methacrylic acid-methyl methacrylate 5 g (copolymerization ratio 82: 8: 10, Mw = 59,000) Microcrystalline wax (mp = 70 ° C.) 45 g Di-t-butylsalicylic acid metal compound 5 g

The above formulation was heated to 60 ° C., and using a TK homomixer (made by Tokushu Kika Kogyo), 12,000 rp
After homogenizing with m, dispersing and dissolving,
Down to 0 ℃,

[0064]

[Chemical 3]

0.75 g (15% of charge control agent) was added. As the polymerization initiator, 2,2'-azobis (2,2'-
4-dimethylvaleronitrile) [t _1/2 = 140 minutes, 6
Under 0 ° C.] 10 g was dissolved to prepare a polymerizable monomer system.

The above polymerizable monomer system was put into the above aqueous medium and stirred at 10,000 rpm for 30 minutes in a TK type homomixer at 60 ° C. under N ₂ atmosphere to obtain a suspension droplet of toner particle size. Granulated.

Then, while stirring with a paddle stirring blade, 60
After raising the temperature from ℃ to 80 ℃ over 30 minutes, increase the liquid temperature to 80
The temperature was kept at 0 ° C. and the polymerization was continued for 12 hours. After the reaction was completed, the suspension was cooled and hydrochloric acid was added to dissolve Ca ₃ (PO ₄ ) ₂ .
After filtration, washing with water and drying, a polymerized toner having a weight average diameter of 8.1 μm was obtained.

A / a and B / b of the obtained toner were 13.21 and 0.17, respectively. The triboelectric charge of this toner started up quickly, and the blocking resistance after standing for 3 days at 50 ° C. was also good.

With respect to 100 parts by mass of the obtained toner, B
0.5 part by mass of hydrophobic silica having a specific surface area of 195 cm ² / g according to the ET method was externally added. To 5 parts by mass of this toner was mixed 95 parts by mass of an acrylic-coated ferrite carrier to prepare a developer.

Using this developer, an image was printed using a commercial color copying machine (CLC-500 Canon) modified machine. The development conditions were a development contrast of 320 V under an environment of 21 ° C./55%.

The unfixed image on the transfer just developed and transferred by a modified machine of CLC-500 is an external fixing machine [where the fixing roller is a fluorinated soft roller and the pressure roller is a silicon roller (oil coating). No function)]
It has become established in. The fixing speed was 90 mm / sec.

As a result, it was possible to obtain a stable and good image without lowering the developing property even after running 25,000 sheets. Also, sufficient fixing property was obtained even without oil.

Example 2 Aromatic oxycarboxylic acid

[0074]

[Chemical 4]

The formulation is the same as in Example 1 except that 2.4 g (48% of the charge control agent) is added. A / a and B / b of the obtained toner are 24.15, 0.
19 and an additional core / shell structure was achieved.

Similar to the toner of Example 1, this toner had a fast rise in the triboelectric charge amount and had good blocking resistance.

Image formation was evaluated using the same formulation as in Example 1. As a result, a stable and high-quality image was obtained without deterioration in developability even after running 20,000 sheets, and oilless fixing was also sufficient. Fixability was taken.

Example 3 Aromatic oxycarboxylic acid

[0079]

[Chemical 5]

And 2.0 g (40% of charge control agent)
Was dispersed in the aqueous medium of Example 1.

Styrene 175 g n-Butyl acrylate 25 g C.I. I. Pigment Blue 15: 3 12 g Styrene-methacrylic acid-methyl methacrylate 8 g (copolymerization ratio 82: 8: 10, Mw = 59,000) Microcrystalline wax (mp = 90 ° C.) 45 g Di-t-butylsalicylic acid metal compound 5 g

The above formulation was heated to 60 ° C. and homogenized at 12,000 rpm using a TK homomixer.
After being dispersed and dissolved, 2,2′-azobis (2,4-dimethylvaleronitrile) [t _1/2 = 140 minutes, under 60 ° C.]
12 g was dissolved to prepare a polymerizable monomer system.

Thereafter, a polymerized toner was obtained in the same manner as in Example 1. A / a and B / b of the obtained toner were 24.93 and 0.24, respectively.

This toner is slightly inferior in granulation property as compared with Example 1, but is excellent in toner charging property, blocking resistance and fixing property, and the developing property is deteriorated even after 20,000 sheets have been run. There wasn't.

Example 4 Aromatic oxycarboxylic acid

[0086]

[Chemical 6]

Then, the formulation is the same as in Example 1 except that 1.8 g (36% of the charge control agent) is added.

A / a and B / b of the obtained toner were 9.41 and 0.22, respectively, and the same results as in Example 1 were obtained.

Example 5 Aromatic oxycarboxylic acid

[0090]

[Chemical 7]

Then, 1.2 g (24% of the charge control agent) was added, and a releasing agent was added as an ester wax having the following structural formula.

[0092]

[Chemical 8]

Then, the formulation is the same as in Example 1 except that 50 g is added.

A / a and B / b of the obtained toner were 7.14 and 0.19, respectively, and the same results as in Example 1 were obtained.

Comparative Example 1 Aromatic oxycarboxylic acid

[0096]

[Chemical 9]

Then, a polymerized toner was obtained in the same manner as in Example 1 except that 0.045 g (0.9% of the charge control agent) was dispersed in the dispersion medium of Example 1.

A / a and B / b of the obtained toner are 0.90 and 0.88, respectively, and the toner chargeability is extremely low. Further, this toner caused blocking due to the presence of a large amount of wax on the toner surface.

Comparative Example 2 Aromatic oxycarboxylic acid

[0100]

[Chemical 10]

2.6 g of the charge control agent (52
%) Was dispersed in a polymerizable monomer to obtain a polymerized toner in the same manner as in Example 1.

A / a and B / b of the obtained toner were 51.19 and 0.70, respectively, and carrier contamination by the charge control agent occurred, and the developability after endurance was remarkably lowered.

Comparative Example 3 Microcrystalline wax (mp = 70 ° C.) 40 g Chromium di-t-butylsalicylate compound 5 g C.I. I. Pigment Yellow 178 g was added to the attritor and dissolved at 120 ° C.
Disperse at 0 rpm for 1 hour, and add to this system.

[0104]

[Chemical 11]

1 g (20% based on the charge control agent) was added and the mixture was further dispersed for 2 hours. Then, it cooled to 60 degreeC and this was heated to 60 degreeC styrene 180g 2 Ethylhexyl acrylate 25g Styrene-methacrylic acid-methyl methacrylate 12g (Copolymerization ratio 82: 8: 10, Mw = 59,000). ) Was added to the monomer system, homogenized at 10,000 rpm using a TK homomixer, dispersed and dissolved, and then 15 g of 2,2′-azobis (2,4dimethylvaleronitrile) was dissolved. Thereafter, a polymerized toner was obtained in the same manner as in Example 1.

The resulting toner has A / a and B /
b was 0.97 and 0.83, respectively, and the same results as in Comparative Example 1 were obtained.

[0107]Comparative Example 4 Polyester resin obtained by condensing bisphenol A diol and fumaric acid 1000 g (Mn = 4000, Mw = 16000, T g = 59 ° C., acid value = 8.1, OH value = 16.1) Paraffin wax (mp = 70 ° C.) 50 g C.I. I. Pigment Yellow 17 35 g Chromium compound di-tert-butylsalicylate 40 g Aromatic oxycarboxylic acid 4 g (10% of charge control agent)

[0108]

[Chemical 12]

After sufficiently premixing with a Henschel mixer, the mixture was melt-kneaded with a twin-screw extruder, cooled, and then coarsely pulverized with a hammer mill to a particle size of about 1 to 2 mm. Then, it was pulverized by an air jet pulverizer.
Further, the obtained finely pulverized product was classified by a multi-division classifier to obtain yellow resin particles having a weight average diameter of 8.5 μm.

The values of A / a and B / b of the obtained toner were 3.31 and 0.97, respectively. The same result as in Comparative Example 1 was obtained.

Comparative Example 5 Microcrystalline Wax (mp = 40 ° C.) 52 g
The same treatment as in Example 1 was carried out except that

A / a and B / b of the obtained toner were 4.81 and 0.83, respectively.

This toner had almost no core / shell structure, the toner charging characteristics and blocking resistance were considerably poor, and the image had already deteriorated after 1,000 sheets were used.

[0114]

According to the present invention, since the charge control agent can be uniformly and strongly present in the vicinity of the toner surface, the contradictory requirements of blocking resistance and fixing property can be satisfied at the same time, and fixing High temperature offset can be prevented without applying a release agent such as oil to the roller.

 ─────────────────────────────────────────────────── ─── Continued Front Page (72) Inventor Takehiko Chiba 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Makoto Kamibayashi 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Incorporated (72) Inventor Kazuyuki Miyano 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc.

Claims (2)

[Claims] 1. A polymerizable monomer having a melting point of 50 to 50.
A toner for developing an electrostatic charge image produced by a polymerization method using a wax having a temperature of 95 ° C., a charge control agent and an aromatic oxycarboxylic acid, wherein the wax and the charge control agent are present within the toner outermost surface layer within 5 nm from the toner surface. However, the toner for developing an electrostatic charge image is characterized by being unevenly distributed to satisfy the following formula. [Equation 1] A: Amount of charge control agent present in toner surface layer (mass%) B: Amount of wax present in toner surface layer (mass%) a; Amount of charge control agent (mass%) b; Charge wax ( mass%) 2. The aromatic oxycarboxylic acid is(R₁, R₂Is hydrogen, hydrocarbon group or O, N, S
Represents a hydrocarbon group containing R₁And R ₂Are the same or different
May be. ), Said charge control agent
1 to 50% by mass relative to
Item 1. The toner for developing an electrostatic image according to Item 1.