JP3397596B2 - toner - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used in recording methods using electrophotography, electrostatic recording, magnetic recording and the like. More specifically, the present invention relates to a toner used in a copying machine, a printer or a fax machine, which forms a toner image on an electrostatic latent image carrier in advance and transfers the toner image onto a transfer material to form an image.

[0002]

2. Description of the Related Art Conventionally, a large number of electrophotographic methods are known, but generally, a photoconductive substance is used to form an electric latent image on a photoconductor by various means, and then,
The latent image is developed with toner to make it a visible image, and if necessary, the toner image is transferred to a transfer material such as paper, and then the toner image is fixed on the transfer material by heat / pressure to obtain a final image. It is a thing.

In recent years, there is an increasing demand for colorization of copying machines, printers and fax machines using electrophotography. Generally, it is difficult to use a magnetic toner containing a magnetic material as a color toner due to its tint, so a non-magnetic toner is used. When a magnetic toner is used as the black toner and a non-magnetic toner is used as the color toner, the optimum transfer current value of the non-magnetic toner tends to be higher than the optimum transfer current value of the magnetic toner. When the transfer conditions of the device body are adjusted to non-magnetic toner, the magnetic toner causes a phenomenon called "retransfer" in which the toner once transferred onto the transfer material returns to the latent image carrier, resulting in a black image. Causes a decrease in concentration.

Further, as paper materials have been further diversified in recent years, it is required that electrophotographic copying machines, printers, and fax machines be compatible with these various paper materials. However, the optimum transfer conditions differ depending on the paper material that is the transfer material. For example, for thick paper or OHT film, the optimum transfer current value is high. On the other hand, for thin paper, the optimum transfer current value is low, and if the transfer conditions of the device body are optimized for thick paper or OHT film, the “retransfer” phenomenon still occurs.

Japanese Unexamined Patent Publication (Kokai) No. 2-66559 and Japanese Unexamined Patent Publication (Kokai) No. 2-
No. 87159, JP-A-2-146557, JP-A-2-167566, JP-A-5-61251 and the like have been proposed that the transfer rate can be improved by subjecting the toner to mechanical shock treatment. There is. Further, JP-A-57-35867 and JP-A-56-10434.
No. 0, JP-A-56-91242, etc., it is said that transferability can be improved by including a magnetic material having a relatively large particle size in the toner as compared with the magnetic material mainly used in the magnetic toner at present. Proposals have been made.

In the methods proposed by these, the transfer rate is certainly improved when the transfer conditions are optimized for the toner, but the transfer efficiency when the transfer current value is set higher than that. Is hardly improved and has no effect on the improvement of "retransfer".

[0007]

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner which solves the above problems of the prior art.

That is, an object of the present invention is to provide a toner capable of obtaining a high image density without causing "retransfer" under a wide range of transfer current conditions (especially under high transfer current conditions).

A further object of the present invention is to provide a toner having a high image density and capable of obtaining an image of good quality.

[0010]

Means for Solving the Problems The toner chromatic one or more endothermic peak in a region 120 ° C. in differential thermal analysis
The toner contains a magnetic substance and a wax component.
To have a toner particle, the toner value of shape factor SF-1 as measured by an image analyzer of particles 120 <SF-1 ≦ 1
60 and the value of the shape factor SF-2 is 115 <SF-2.
≦ 140 and a value B obtained by subtracting 100 from the SF-2 value
The ratio B / A of the SF-1 value the value obtained by subtracting 100 from A is Ri der 1.0 was determined by GPC of the wax component
In the molecular weight distribution, Mw / Mn is 1.0 to 2.0
Ri, the average particle diameter of the magnetic substance can solve the above problems by using a toner, wherein this <br/> and is 0.1 to 0.6 .mu.m.

The inventors of the present invention conducted a study for the purpose of solving "retransfer" and found that "retransfer" can be solved by increasing the charge amount of toner before transfer.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The above electrostatic latent image bearing before transfer is carried out by using a toner having the above-mentioned specific shape with less unevenness and having an endothermic peak in the differential thermal analysis as described above. The charge amount of the toner on the body or the intermediate transfer body can be made higher than before, and “retransfer” can be prevented.

The reason why the toner of the present invention can obtain the "retransfer" preventing effect is considered as follows.

Endothermic peak in differential thermal analysis is 120 ° C.
The toners below have a "certain peculiar surface state" in which the state of dispersion of the magnetic substance, charge control agent, etc. in the binder resin is different from the toner having no endothermic peak at 120 ° C or less in the melt-kneading process in the production. It is supposed to have become.

Further, it is speculated that the characteristic of the unique surface state is more greatly exhibited due to the shape having less unevenness, and the effect of preventing "retransfer" is obtained.

Further, when a magnetic material having a large average particle size is used, the amount of magnetic material exposed on the toner surface is reduced, the toner surface has a high resistance, and the toner charge amount is increased, so that "retransfer" is prevented. It is speculated that the effect will be obtained.

The toner of the present invention has one or more endothermic peaks in differential thermal analysis at 120 ° C. or lower (more preferably 110 ° C. or lower).

Endothermic peak in differential thermal analysis is 120 ° C.
If none of the following exists, the effect of preventing "retransfer" cannot be sufficiently obtained.

Endothermic peak in differential thermal analysis is 120 ° C.
It is effective if at least one of the following is present, and the endothermic peak may be at a position exceeding 120 ° C.
However, the endothermic peak in differential thermal analysis is preferably not present to less than 60 ° C. (preferably below 70 ° C.). When the endothermic peak in the differential thermal analysis is below 60 ° C., the image density tends to be low. In addition, storage stability tends to be unstable.

The endothermic peak in the differential thermal analysis is 120 ° C.
As a means to have the form described below, a method of internally adding a compound having an endothermic peak in differential thermal analysis at 120 ° C. or lower is preferable.

The endothermic peak in the differential thermal analysis is 120 ° C.
Examples of the substance having one or more of the following include resins and waxes.

Examples of the resin include crystalline polyester resin and silicone resin.

As the wax, paraffin wax,
Petroleum wax and its derivatives such as microcrystalline wax and petrolactam, montan wax and its derivatives, hydrocarbon wax and its derivatives by the Fischer-Tropsch method, polyolefin wax represented by polyethylene and its derivatives, carnauba wax,
Natural waxes such as candelilla wax and their derivatives, and the like include oxides, block copolymers with vinyl monomers, and graft modified products. Alcohols such as higher aliphatic alcohols; fatty acids such as stearic acid and palmitic acid or compounds thereof; acid amides, esters, ketones, hydrogenated castor oil and its derivatives, vegetable waxes, animal waxes, etc.
Any material having a temperature of not higher than 0 ° C can be used.

Among these, the compound having an endothermic peak in differential thermal analysis at 120 ° C. or lower is one or more selected from the group consisting of polyolefin wax, hydrocarbon wax by Fischer-Tropsch method, petroleum wax and higher alcohol. The wax component is preferably, and more preferably a polyolefin wax,
One or more wax components selected from the group consisting of hydrocarbon waxes and petroleum waxes by the Fischer-Tropsch method are particularly preferable in the toner of the present invention.

When the above-mentioned specific compound is used,
The effect of preventing "retransfer" is further enhanced.

It is considered that these compounds have relatively low polarities, stabilize the charging of the toner, and increase the charging amount of the toner on the electrostatic latent image bearing member or the intermediate transfer member.

Among them, the compound having an endothermic peak in differential thermal analysis at 120 ° C. or lower is a polyolefin wax, a hydrocarbon wax by the Fischer-Tropsch method, a petroleum wax or a higher alcohol, the weight of which is measured by GPC. Ratio (Mw / M) of average molecular weight (Mw) and number average molecular weight (Mn)
When n) is 1.0 to 2.0, the effect of preventing "retransfer" is further enhanced. (Mw / Mn) is 1.0 to 2.0
By incorporating the above wax having a considerably sharp molecular weight distribution into the toner, the state of dispersion of the magnetic material, charge control agent, etc. in the binder resin in the melt kneading step in the production of the toner is more preferable for the present invention. I think it will be.

The toner of the present invention has a shape factor SF-1 of 110 <SF- measured by an image analyzer for toner particles.
1 ≦ 180 (more preferably 120 <SF−1 ≦ 1
60), the value of the shape factor SF-2 is 110 <SF-2 ≦ 1.
40 (more preferably 115 <SF-2 ≦ 140)
And SF− is obtained by subtracting 100 from SF−2 and SF−
The ratio B / A with the value A obtained by subtracting 100 from the value of 1 is 1.0 or less (preferably 0.20 to 0.95).

When SF-1 is 110 or less, SF-
When 2 is 110 or less, and when the ratio B / A exceeds 1.0, it is difficult to clean the transfer residual toner remaining on the latent image carrier, and cleaning failure is likely to occur.

When SF-1 exceeds 180, and S
If F-2 exceeds 140, further improvement of the "retransfer" preventing effect cannot be obtained sufficiently.

The following method can be used to control the shape of the toner of the present invention within the above range.

Examples of the method include fine pulverization using a mechanical impact type fine pulverization device and jet pulverization in which the pulverization pressure is lowered than usual to increase the number of circulations and fine pulverization. Further, a hot water bath method in which finely pulverized or further classified toner particles are dispersed and heated in water, a heat treatment method in which a hot air stream is passed, a mechanical impact method in which mechanical energy is applied, and the like are included. .

Of these, the method of applying treatment by mechanical impact force is preferable. Examples of the process for applying a mechanical impact force include, for example, a method for applying a mechanical impact force to a toner using a mechanical impact type crusher such as Kawasaki Heavy Industries Ltd.'s Kryptron system or Turbo Industry's turbo mill, or Hosokawa Micron. Like devices such as the Mechano-Fusion System manufactured by the company and the Hybridization System manufactured by Nara Machinery Co., Ltd., the toner is pressed against the inside of the casing by centrifugal force by the blades that rotate at high speed, and becomes the toner by the force such as compression force and friction force. A method of applying a mechanical impact force can be mentioned.

The process of applying a mechanical impact force is particularly preferable when it is carried out after the finely pulverizing step of the toner or after the classification step, because the effect of preventing "retransfer" is further enhanced. The reason why the effect of preventing "retransfer" is further enhanced by applying the process of applying the mechanical impact force is that the distribution state of the magnetic substance, the charge control agent, etc. on the toner surface is increased by the process of applying the mechanical impact force according to the present invention. For us, we think that it will be in a more favorable state.

Examples of the binder resin usable in the present invention include the following. In the case of a heat fixing toner, for example, a homopolymer of styrene such as polystyrene, poly-p-chlorostyrene, polyvinyltoluene, or a substitution product thereof; a styrene-vinylnaphthalene copolymer, a styrene-acrylic acid ester copolymer, Styrene-methacrylic acid ester copolymer, styrene-maleic acid ester copolymer, styrene-acrylic acid copolymer, styrene-methacrylic acid copolymer, styrene-maleic acid copolymer, styrene-α-chloromethyl methacrylate Copolymer, styrene-acrylonitrile copolymer, styrene-
Styrene type such as vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile indene copolymer Copolymer; polyvinyl chloride,
Phenolic resin, natural modified phenolic resin, natural resin modified maleic acid resin, acrylic resin, methacrylic resin, polyvinyl acetate, silicone resin, polyester resin, polyurethane, polyamide resin, furan resin, epoxy resin, xylene resin, polyvinyl butyral, tempen resin , Coumarone indene resin, petroleum resin, etc. can be used.

Of these, styrene copolymers are particularly preferable. It is considered that the styrene copolymer has a relatively low main-chain polarity, stabilizes the charging of the toner base, and increases the charge amount of the toner on the electrostatic latent image carrier or the intermediate transfer member. ing.

Examples of the comonomer for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate,
Didecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. A monocarboxylic acid having a heavy bond or a substituted product thereof; acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid and crotonic acid, and α- or β-alkyl derivatives thereof, fumaric acid, maleic acid, citraconic acid Unsaturated dicarboxylic acids and their monoester derivatives, maleic anhydride, etc. are available. Such monomers can be used alone or in admixture and copolymerized with other monomers to produce a desired polymer.

Among these, it is particularly preferable to use a monoester derivative of unsaturated dicarboxylic acid. More specifically, for example, monomethyl maleate, monoethyl maleate, monobutyl maleate, monooctyl maleate, monoallyl maleate, monophenyl maleate,
Α-, β such as monomethyl fumarate, monoethyl fumarate, monobutyl fumarate, monophenyl fumarate etc.
-Unsaturated dicarboxylic acid monoesters; alkenyldicarboxylic acids such as n-butenyl monosuccinate, n-octenyl monosuccinate, n-butenyl malonate monoethyl, n-dodecenyl glutarate monomethyl, n-butenyl adipate monobutyl and the like. Monoesters of aromatic dicarboxylic acids such as phthalic acid monomethyl ester, phthalic acid monoethyl ester, phthalic acid monobutyl ester, etc .; Vinyl such as vinyl chloride, vinyl acetate, vinyl benzoate, etc. Esters, for example, ethylene-based olefins such as ethylene, propylene, butylene, etc .; vinyl ketones, such as vinyl methyl ketone, vinyl hexyl ketone, etc .; for example, vinyl methyl ether, vinyl ethyl ether, vinyl iso Vinyl ethers such as Chirueteru; vinyl monomers are used alone or in combination.

As the cross-linking agent, a compound having two or more polymerizable double bonds is mainly used. For example, an aromatic divinyl compound such as divinylbenzene, divinylnaphthalene, etc .; Carboxylic acid ester having two double bonds such as acrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide and divinyl sulfone, and 3 or more. The compounds having a vinyl group can be used alone or as a mixture.

The toner of the present invention is particularly effective in the case of a magnetic toner containing a magnetic material in the toner.

As the magnetic substance contained in the toner of the present invention, powder of an alloy or compound containing a ferromagnetic element is preferable. For example, magnetite, maghemite, ferrite, etc., alloys and compounds of iron, cobalt, nickel, manganese, zinc, etc., other ferromagnetic alloys, etc., which are conventionally known as magnetic materials can be mentioned.

The BET specific surface area of the magnetic substance by the nitrogen gas adsorption method is 1 to 40 m ² / g, further ^{2 to} 30 m ²
/ G is preferable.

The magnetic material used in the toner of the present invention has an average particle size of 0.3 to 3 μm (preferably 0.6 to 2).
It is possible to use those having a large particle size of (μm). When a magnetic material having such a large average particle size is used, the effect of preventing "retransfer" is further enhanced. Average particle size of magnetic material is 0.4μ
When it is less than m, further improvement of the "retransfer" preventing effect cannot be sufficiently obtained. When the average particle size of the magnetic material exceeds 3 μm, the dispersion of the magnetic material in the binder resin deteriorates,
It is easy to damage the photoconductor.

On the other hand, a small particle size having an average particle size of 0.05 to 1 μm (preferably 0.1 to 0.6 μm) can be used. In this case, the shape is a substantially spherical magnetic substance. Is preferred. Unlike the case where the state of dispersion of the magnetic substance in the binder resin in the melt-kneading step in the production uses a magnetic substance having a shape other than substantially spherical, a certain specific surface state becomes a more preferable form, It is thought that the effect of preventing the "retransfer" of the fine particles of (1) makes it easier to work. The shape of the magnetic substance is “substantially spherical”, by using an electron micrograph of the magnetic substance.
The average of the ratio of major axis to minor axis (major axis / minor axis) of 0 or more is 1.0 to 1.2.

As a method for producing the magnetic material used in the present invention, an alkaline aqueous solution is added to an iron sulfate (2+) aqueous solution,
Obtained by obtaining iron hydroxide, feeding oxygen into this aqueous solution, and performing an oxidation reaction, and by a granulation and sintering of fine particles such as iron oxide and iron chloride, and reduction treatment if necessary. A dry method can be mentioned.

Further, the magnetic substance is a binder resin 100 in the toner.
It is preferable to contain 60 parts by mass to 200 parts by mass, more preferably 80 parts by mass to 150 parts by mass with respect to parts by mass.

In the toner of the present invention, a charge control agent can be used by blending (internal addition) with the toner particles or by mixing (external addition) with the toner particles, which is preferable. The charge control agent makes it possible to control the optimum charge amount according to the developing system, and particularly in the present invention, the balance between the particle size distribution and the charge amount can be further stabilized.

To control the toner to be negatively charged,
For example, there are the following substances.

Organic metal complexes and chelate compounds are effective, for example, monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid type metal complexes. Other examples include aromatic hydroxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol.

Further, the following substances are exemplified as those which are controlled to be positively charged.

Modified products of nigrosine and fatty acid metal salts and the like; quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate, and phosphonium salts which are analogs thereof. Onium salts and lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as a laker, phosphotungstic acid, phosphomolybdic acid, phosphotungstic molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide) Compounds, ferrocyanides, etc.), metal salts of higher fatty acids; diorganotin borates such as dibutyltin oxide, dioctyltin oxide, dicyclohexyltin borate; these can be used alone or in combination of two or more.

The above charge control agents are preferably used in the form of fine particles, and in this case, the number average particle diameter of these charge control agents is preferably 4 μm or less, more preferably 3 μm or less. When internally adding these charge control agents to the developer,
It is preferable to use 0.1 to 20 parts by mass, particularly 0.2 to 10 parts by mass, relative to 100 parts by mass of the binder resin.

In the toner of the present invention, it is preferable that the inorganic fine powder is externally added to the developer.

The inorganic fine powder is preferably contained in the developer by stirring and mixing the developer with a mixer such as a Henschel mixer.

As the inorganic fine powder used in the present invention,
Inorganic fine powder such as silicic acid fine powder, titanium oxide, and aluminum oxide is preferable, and silicic acid fine powder is particularly preferable. For example, as the silicic acid fine powder, both a so-called dry method produced by vapor phase oxidation of a silicon halide or a dry silica called fumed silica and a so-called wet silica produced from water glass or the like can be used. However, there are few silanol groups on the surface and inside the silica fine powder,
Further, dry silica having less production residue such as Na ₂ O and SO ₃ ²⁻ is preferable. Further, in the case of dry silica, in the manufacturing process, for example, aluminum chloride, titanium chloride, etc.
By using another metal halogen compound together with a silicon halogen compound, it is possible to obtain a composite fine powder of silica and another metal oxide, and it is also possible to include them.

It is also possible to use one whose surface has been made hydrophobic by an organic compound in advance. Examples of such an organic treatment method include a method of treating with an organometallic compound such as a silane coupling agent or a titanium coupling agent which reacts or physically adsorbs with the inorganic fine powder; or after treatment with a silane coupling agent, or silane. A method of treating with a coupling agent and at the same time treating with an organic silicon compound such as silicone oil can be mentioned.

[0057] Inorganic fine powder used in the present invention the specific surface area according to the measured nitrogen adsorption 30 m ² / g or more by the BET method, particularly preferably in the range of 50 to 400 m ² / g.

The weight average particle diameter of the toner is 10.0 μm.
It is preferably m (preferably 8.0 μm) or less. When the weight average particle diameter of the toner is 10.0 μm or less, the effect of preventing “retransfer” is further enhanced. It is considered that when the weight average particle diameter of the toner is 10.0 μm or less, the charge amount of the toner on the electrostatic latent image carrier or the intermediate transfer body before transfer is further increased.

Further, as a method for producing the toner of the present invention, the following methods can be mentioned. In the production of the toner according to the present invention, a mixing process using the above-mentioned constituent materials using a mixer such as a Henschel mixer, a ball mill, a V-type mixer, a heat roll kneader and an extruder is used. Kneading step, after cooling and solidifying the kneaded product, a crushing step using a crusher such as a jet mill,
It is preferably manufactured through a manufacturing process including at least the above process. Further, if necessary, it is also preferable to go through a classification step of the pulverized material.

Among these, a production method having at least a step of melt-kneading the binder resin and the other composition and a pulverization step of finely pulverizing the binder resin is particularly preferable in the production step.

In the melt-kneading step, when the endothermic peak in the differential thermal analysis is 120 ° C. or less, the dispersion state of the magnetic substance and the charge control agent in the binder resin becomes the preferable state for the present invention, and the powder is crushed. By doing so, a certain peculiar state is exposed as it is on the toner surface, and the effect of preventing "retransfer" of the toner of the present invention is exhibited.

In the present invention, SF-indicating the shape factor
1 and SF-2 are, for example, Hitachi FE-SEM
(S-800) is used to randomly sample 100 toner images of 2 μm or more magnified 1000 times, and the image information is introduced into an image analysis device (LuzexIII) manufactured by Nicolet Co., Ltd. through an interface for analysis. And the values obtained by the calculation using the following equation are used as shape factors SF-1, S
It is defined as F-2.

[0063]

[Equation 1]

(Where MXLNG is the absolute maximum length of the particle,
PERIME represents the perimeter of the particle, and AREA represents the projected area of the particle. )

The shape factor SF-1 indicates the degree of roundness of the toner particles, and the shape factor SF-2 indicates the degree of unevenness of the toner particles.

The endothermic peak in the differential thermal analysis according to the present invention is measured by a highly accurate internal heat input compensation type differential scanning calorimeter. For example, DSC- manufactured by Perkin Elmer
7 can be used. The measuring method is ASTM D3418-
82. The DSC curve used in the present invention is
After raising the temperature once and taking the previous history, the temperature rate was 10 ° C / mi.
n, a DSC curve measured when the temperature is raised and lowered in the temperature range of 0 to 200 ° C is used. What is the endothermic peak temperature?
In the DSC curve, it is the peak temperature in the positive direction, that is, the point at which the differential value of the peak curve becomes 0 when the differential value changes from positive to negative.

The weight average particle diameter of the toner of the present invention is measured by using Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Co.). 1 electrolyte
Prepare a 1% aqueous NaCl solution using graded sodium chloride. For example, ISOTONR-II (manufactured by Coulter Scientific Japan) can be used. As the measuring method, 0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant to 100 to 150 ml of the electrolytic aqueous solution, and 2 to 5 measuring samples are further added.
Add 20 mg. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and a 100 μm aperture is used as a rear aperture by the above measuring device to
The volume distribution and the number distribution of the toner having a size of μm or more were measured to calculate the volume distribution and the number distribution. Then, a weight-based weight average particle diameter D4 (the median value of each channel is set as a representative value for each channel) determined from the volume distribution according to the present invention was determined.

[0068]

EXAMPLES The present invention will now be described in more detail by way of examples, which should not be construed as limiting the invention.

(Toner Production Example 1) Styrene-butyl acrylate-butyl maleate-half ester copolymer 100 parts by mass Magnetite (shape: spherical, average particle size: 0.2 μm) 100 parts by mass Iron complex of monoazo dye ( Negative charge control agent) 2 parts by mass Low molecular weight polyethylene (differential thermal analysis endothermic peak: 102 ° C, Mw / Mn: 1.3) 4 parts by mass Biaxial kneading extrusion set to 130 ° C after premixing the above materials Melt kneading was performed by a machine. After cooling the kneaded product, it was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified by an air classifier.

Further, the surface was treated by mechanical impact to obtain a black powder toner base.

Toner 1 was prepared by mixing 100 parts by mass of the above black fine powder toner base and 1.2 parts by mass of dry silica treated with hexamethyldisilazane / dimethylsilicone oil with Henschel mixer 10B at 3200 rpm for 2 minutes. Got

The toner 1 thus obtained had a weight average particle diameter of 6.9.
μm, SF-1 144, SF-2 126, ratio B / A
Was 0.59. The endothermic peak in the differential thermal analysis was 102 ° C.

(Toner Production Examples 2 to 8) Instead of the low molecular weight polyethylene added in Toner Production Example 1, Table 1
Toners 2 to 8 were obtained in the same manner as in Toner Production Example 1 except that the substances shown in 1 were added.

(Toner Production Examples 9 to 11) Toner Production Example 1
In the same manner as in Toner Production Example 1 except that the shape shown in Table 1 was adjusted by not performing the mechanical shock treatment carried out in 1. and adjusting the conditions of the mechanical shock treatment.
I got 11.

(Toner Production Example 12) Polyester resin (condensation polymer of propoxylated bisphenol and fumaric acid) 100 parts by mass Magnetite (shape: octahedron, average particle size: 0.2 μm) 60 parts by mass Iron complex of monoazo dye ( Negative charge control agent) 2 parts by mass Low molecular weight polypropylene (differential thermal analysis endothermic peak: 145 ° C, Mw / Mn: 8.8) 4 parts by mass After premixing the above materials, biaxial kneading extrusion set to 130 ° C Melt kneading was performed by a machine. After cooling the kneaded material, it was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified by an air classifier to obtain a black fine powder toner base.

The above black fine powder: 100 parts by mass,
Hexamethyldisilazane / dimethyl silicone oil treated dry silica: 0.4 parts by mass of Henschel mixer 10
Toner 12 was obtained by stirring and mixing with B at 3200 rpm for 2 minutes.

The weight average particle diameter of the obtained toner 12 is 1
1.3 μm, SF-1 was 160, SF-2 was 154, and the ratio B / A was 0.90. The endothermic peak in the differential thermal analysis was 145 ° C.

(Toner Production Example 13) Styrene-butyl acrylate copolymer 100 parts by mass Magnetite (shape: spherical, average particle size: 0.2 μm, Mw / Mn: 1.3) 80 parts by mass Triphenylmethane dye (Positive charge control agent) 2 parts by mass Low molecular weight polyethylene (differential thermal analysis endothermic peak: 102 ° C.) 4 parts by mass After the above materials were premixed, melt kneading was performed by a twin-screw kneading extruder set to 130 ° C. . After cooling the kneaded product, it was roughly pulverized, finely pulverized by a pulverizer using a jet stream, and further classified by an air classifier.

Further, the surface treatment was carried out by mechanical impact to obtain a black fine powder toner base.

The above black fine powder: 100 parts by mass,
Amino-modified silicone oil-treated dry silica: 0.8 parts by mass was agitated and mixed with Henschel mixer 10B at 3200 rpm for 2 minutes to obtain toner 13.

The weight average particle size of the obtained toner 13 is 7.
6 μm, SF-1 146, SF-2 124, ratio B /
A was 0.52. The endothermic peak in the differential thermal analysis was 102 ° C.

Examples 1 to 8, Reference Examples 1 to 3 and Comparative Example 1
-2 The toners of Production Examples 1 to 13 described above were evaluated by the following methods. The results are shown in Tables 2 and 3.

<Evaluation of Transferability> (Regarding Toners of Production Examples 1 to 11) A laser beam printer LBP-1260 manufactured by Canon was remodeled and an apparatus equipped with a variable transfer bias power source was used to obtain 23 ° C./60%.
Develop a solid black image in the RH environment, transfer it to a transfer paper of 75 g / m ² , transfer the residual image on the photoconductor with a transparent polyester adhesive tape, and stick it on a white paper.
The reflection density was measured by a Macbeth reflection densitometer, and as a standard, the density of a portion where only the tape was stuck on a white paper was subtracted from the value to evaluate.

The transfer voltage was evaluated in steps of 0.5 kV from +1.0 to +3.0 kV.

(Regarding Toner of Manufacturing Example 12) A solid black image was developed in an environment of 23 ° C./60% RH by using a device in which a copying machine FC330 manufactured by Canon was modified and a variable transfer bias power source was attached, and 60 g / m ² ) Transfer the image onto the transfer paper, transfer the residual image on the photoconductor with a transparent polyester adhesive tape, stick it on a white paper, measure the reflection density with a Macbeth reflection densitometer, and use only the tape as standard. The value obtained by subtracting the density of the portion pasted on a white paper was evaluated.

The transfer voltage was evaluated in 0.5 kV steps from -3.0 to -5.0 kV.

[0087]

[Table 1]

[0088]

[Table 2]

[0089]

[Table 3]

[0090]

[0091]

[0092]

[0093]

[0094]

[0095]

[0096]

[0097]

[0098]

[0099]

[0100]

[0101]

[0102]

[0103]

[0104]

[0105]

[0106]

[0107]

[0108]

[0109]

[0110]

According to the present invention, "retransfer" does not occur even under a high transfer current condition, and an image having a high image density and good image quality can be obtained.

(72) Inventor Yuki Karaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (72) Inventor Kazuo Maruyama 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. (56) References JP-A-3-9371 (JP, A) JP-A-6-308759 (JP, A) JP-A-7-36207 (JP, A) JP-A-61-279864 (JP, A) (JP 58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (14)

(57) [Claims] 1. The endothermic peak in differential thermal analysis is 120.
A toner having one or more in the range of ℃ or less, the toner containing a magnetic substance and a wax component
It has a particle shape factor as measured by the image analyzer of the toner particles SF-
The value of 1 is 120 <SF-1 ≤ 160 , and the shape factor S
The value of F-2 is 115 <SF-2 ≦ 140 , and SF−
The value of 2 minus 100 minus the value of SF-1 and 10
The ratio B / A of the value A obtained by subtracting the zero Ri der 1.0, the molecular weight distribution odor as measured by GPC of the wax component
And Mw / Mn is 1.0 to 2.0, and the average particle diameter of the magnetic material is 0.1 to 0.6 μm . 2. The toner according to claim 1, wherein the toner has one or more endothermic peaks in a differential thermal analysis in the region of 60 ° C. to 120 ° C. 3. The toner according to claim 2, wherein the toner has one or more endothermic peaks in a differential thermal analysis in a region of 70 ° C. or higher. 4. The toner according to claim 2 or 3, wherein the toner has one or more endothermic peaks in a differential thermal analysis in a region of 110 ° C. or lower. 5. The toner is a polyolefin wax,
5. The toner according to claim 1, further comprising at least one wax component selected from the group consisting of hydrocarbon wax, petroleum wax and higher alcohol by Fischer-Tropsch method. 6. The toner is a polyolefin wax,
5. A wax composition comprising one or more wax components selected from the group consisting of hydrocarbon wax and petroleum wax by the Fischer-Tropsch method.
The toner according to any one of 1. As 7. binder resin of the toner, the toner according to any one of claims 1 to 6, characterized in that a styrene copolymer. 8. A magnetic member, the toner according to any one of claims 1 to 7, characterized in that the shape is almost magnetic iron oxide spherical. 9. The toner has a weight average particle diameter of 10.0 μm.
The toner according to any one of claims 1 to 8, characterized in that m or less. 10. The toner has a weight average particle diameter of 8.0 μm.
The toner according to any one of claims 1 to 9 , wherein the toner is m or less. 11. The toner in the production process of the toner, of claims 1 to 10, comprising a step of grinding at least a binder resin and a coloring agent to the melt-kneading step and the resulting kneaded product The toner according to any one. 12. The toner according in the process of manufacturing the toner, to claim 11, characterized in that the spheronization process of adding at least mechanical impact to the toner particles. 13. The toner according to claim 12 , wherein the spheroidizing treatment is performed after a pulverizing step. 14. The toner particles are formed by mechanical impact force.
The surface treatment is performed according to claim 1.
Toner.