JPH1048870A - Negative charge type toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent retransfer under various conditions of electric current for transfer and to attain high image density by adding specified fine particles of an N-contg. high molecular compd. to toner matrix particles and imparting a specified heat absorption peak. SOLUTION: Fine particles of an N-contg. high molecular compd. having 0.05-2.0μm, preferably 0.1-1.0μm average particle diameter are stuck to toner matrix particles preferably by 0.01-0.3 part by mass to obtain the objective negative charge type toner having one or more heat absorption peaks by differential thermal analysis in a range of <=120 deg.C. The N-contg. high molecular compd. is, e.g. a polymer having amino groups in a side chain or a resin copolymer having amido bonds. A compd., resin or wax having one or more heat absorption peaks by differential thermal analysis in a range of <=120 deg.C is preferably contained in the toner so that the toner has one or more heat absorption peaks by differential thermal analysis in a range of <=120 deg.C.

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 a recording method utilizing an electrophotographic method, an electrostatic recording method, a magnetic recording method, or the like. More specifically, the present invention relates to a toner used in a copying machine, a printer, and a facsimile, which forms an image by forming a toner image on an electrostatic latent image carrier in advance and transferring the toner image onto a transfer material.

[0002]

2. Description of the Related Art Conventionally, many methods have been known as electrophotography. In general, a photoconductive substance is used to form an electric latent image on a photoreceptor by various means.
The latent image is developed with a 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. Things.

In recent years, there has been a great demand for color copying machines, printers and faxes using electrophotography. Generally, it is difficult to use a magnetic toner containing a magnetic material because of the color of the color toner. Therefore, a non-magnetic toner is used. When a magnetic toner is used for the black toner and a non-magnetic toner is used for 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 condition of the device body is adjusted to the non-magnetic toner, a phenomenon called “re-transfer” occurs in which the magnetic toner once transferred onto the transfer material returns to the latent image carrier, resulting in a black image. Causes a decrease in concentration.

[0004] In recent years, further diversification of paper materials has been progressing, and it is required that copiers, printers, and faxes using electrophotography can cope with such versatile paper materials. However, the optimum transfer conditions differ depending on the paper material as the transfer material. For example, in the case of thick paper or an 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 apparatus main body are optimized for thick paper or OHT film, the "re-transfer" phenomenon also occurs.

[0005] JP-A-2-66559, JP-A-2-
JP-A-87159, JP-A-2-146557, JP-A-2-167566, JP-A-5-61251 and the like have proposed that the transfer rate can be improved by subjecting toner to mechanical shock treatment. I have.

In the methods proposed in these publications, the transfer rate is surely improved when the transfer condition is set to the highest transfer efficiency for the toner. However, 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 negatively chargeable toner which has solved the above-mentioned problems of the prior art.

That is, an object of the present invention is to provide a negatively chargeable toner which can obtain a high image density without causing "retransfer" under a wide range of transfer current conditions (particularly under a high transfer current condition).

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

[0010]

Means for Solving the Problems The average particle size is 0.05 to
A polymer compound containing a 2.0 μm nitrogen atom, or a polymer containing a methyl methacrylate unit, or a fatty acid compound, or a fine particle composed of a phenol resin is externally added to the toner mother particles, and the differential thermal analysis is performed. The above problem can be solved by using a negatively chargeable toner having one or more endothermic peaks at 120 ° C. or lower.

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

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION The average particle size is 0.05 to 2.0 μm.
m, more preferably a polymer compound containing a nitrogen atom of 0.1 to 1.0 μm, or a polymer containing a methyl methacrylate unit, or a fine particle composed of a fatty acid compound or a phenol resin. And the endothermic peak in the differential thermal analysis is 120 ° C.
By using a negatively-chargeable toner having one or more of the following, the charge amount of the toner on the electrostatic latent image carrier or the intermediate transfer body before the above-described transfer can be made higher than before, and the “re-transfer” can be performed. Could be prevented.

At the time of development and transfer, the fine particles are separated from the toner matrix, and the fine particles impart a negative charge to the negatively chargeable toner matrix itself, thereby preventing "retransfer" to increase the charge amount of the toner before transfer. I think we can do it.

If the average particle diameter of the fine particles is less than 0.05 μm, the adhesion of the fine particles to the toner surface is too large, the separation from the toner matrix does not sufficiently occur during development / transfer, and the charge amount of the toner before transfer Is not effective in preventing "retransfer".

If the average particle diameter of the fine particles exceeds 2.0 μm, the surface area of the fine particles is small, the effect of increasing the tribo of the toner before transfer is small, and there is no effect of preventing “re-transfer”. In addition, aggregation of toner particles may occur with fine particles as nuclei, which may cause an increase in fog.

The fine particles are used in a form externally added to a negatively chargeable toner base. When the fine particles are in the state of being internally added to the toner matrix and in the state of being strongly fixed to the toner surface,
It is not possible to increase the charge amount of the toner before transfer, and it is not effective in preventing “re-transfer”.

The amount of the fine particles added to the toner is 0.01 to 0.3 mass when the fine particles are made of a polymer compound containing a nitrogen atom and when the fine particles are made of a polymer containing a methyl methacrylate unit. Part.
If the amount of the fine particles added to the toner is less than 0.01 part by mass, the effect of increasing the charge amount of the toner before transfer is insufficient, and the effect of preventing “retransfer” cannot be sufficiently obtained. If the amount of the fine particles added to the toner exceeds 0.3 parts by mass, fogging tends to occur.

When the fine particles are made of a fatty acid compound or a phenol resin, the amount of the fine particles added to the toner is preferably 0.05 to 1.0 part by mass. If the amount of the fine particles added to the toner is less than 0.05 parts by mass, the effect of increasing the charge amount of the toner before transfer is insufficient, and the effect of preventing "retransfer" cannot be sufficiently obtained. If the amount of the fine particles added to the toner exceeds 1.0 part by mass, fogging tends to occur.

Examples of the high molecular compound containing a nitrogen atom include a polymer having a nitrogen element such as an amino group in a side chain, a resin copolymer having an amide bond, a melamine-formaldehyde resin, and a benzoguanamine-formaldehyde resin. Copolymers and the like can be mentioned.

The fine particles made of a polymer compound containing a nitrogen atom are preferably those which themselves have a positive charging property. When the fine particles made of a polymer compound containing a nitrogen atom have positive chargeability, the effect of preventing "retransfer" is further enhanced.

Of these, melamine-formaldehyde resin and benzoguanamine-formaldehyde resin copolymer are particularly preferred. When a melamine-formaldehyde resin or a benzoguanamine-formaldehyde resin copolymer is used as the fine particles, the effect of preventing "retransfer" is further enhanced. It also has the effect of increasing the image density (especially the image density when left in a high humidity environment).

The polymer containing a methyl methacrylate unit may be a polymer composed of only methyl methacrylate, or a copolymer with a styrene monomer, another acrylic monomer or the like. Further, a crosslinked polymer is also preferable.

The fine particles comprising a polymer containing methyl methacrylate units are preferably those which themselves have a positive charge. When the fine particles made of a polymer containing a methyl methacrylate unit have positive chargeability, the effect of preventing “retransfer” is further enhanced.

Examples of the fatty acid compound include fatty acids such as stearic acid and lauric acid, and metal salts or ester compounds thereof.

Among these, fatty acid metal salts are particularly preferred. When a fatty acid metal salt is used as the fine particles, the effect of preventing "retransfer" is further enhanced. The fine particles composed of a fatty acid compound preferably have a positively chargeable property.
When the fine particles comprising a fatty acid compound have a positive charge property,
The effect of preventing "retransfer" is further enhanced.

As the phenol resin, any resin obtained by a condensation reaction of phenols such as phenol and cresol with aldehydes such as formaldehyde and acetaldehyde can be used. Typically, a phenol-formaldehyde resin can be mentioned.

The fine particles made of a phenol resin are preferably those that themselves have a positive charge property. When the fine particles made of a phenol resin have positive chargeability, the effect of preventing "retransfer" is further enhanced.

The toner of the present invention has an endothermic peak in differential thermal analysis of 120 ° C. or less (more preferably 11 ° C. or less).
0 ° C or lower).

Endothermic peak in differential thermal analysis is 120 ° C.
If not, the effect of preventing "retransfer" by externally adding the fine particles of the present invention cannot be sufficiently obtained.

The endothermic peak in the differential thermal analysis is 120 ° C.
The following toners have a unique state in which the dispersion state of the magnetic substance / charge control agent in the binder resin in the melt-kneading step in the production thereof is different from the toner having an endothermic peak not higher than 120 ° C. It is presumed. It is considered that such a specific state makes the effect of preventing "retransfer" of the specific fine particles of the present invention easy to work.

The endothermic peak in the differential thermal analysis is 120 ° C.
At least one of the following is effective, and the endothermic peak may be at a temperature exceeding 120 ° C.
However, it is preferable that the endothermic peak in the differential thermal analysis does not exist at 60 ° C. or lower (preferably 70 ° C. or lower). When the endothermic peak in the differential thermal analysis exists at 60 ° C. or lower, the image density tends to be low. In addition, storage stability tends to be unstable.

The endothermic peak in the differential thermal analysis was 120 ° C.
As a means for providing the following mode, a method of internally adding a compound having an endothermic peak at 120 ° C. or lower in differential thermal analysis to the toner is preferable.

The endothermic peak in the differential thermal analysis was 120 ° C.
Examples of the substance having one or more of the following include a resin and a wax.

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

Petroleum waxes such as paraffin wax, microcrystalline wax, petrolactam and derivatives thereof, montan wax and derivatives thereof, hydrocarbon waxes and derivatives thereof by the Fischer-Tropsch method, polyolefin waxes represented by polyethylene and derivatives thereof, carnauba Wax, candelilla wax, etc., natural waxes and their derivatives, etc. The derivatives include oxides, block copolymers with vinyl monomers,
Also includes 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 derivatives thereof, vegetable waxes, animal waxes, etc .; Any of the following can be used.

Among these, the compound having an endothermic peak at 120 ° C. or lower in the differential thermal analysis is a polyolefin or a hydrocarbon wax or a petroleum-based wax or a higher alcohol by the Fischer-Tropsch method. Particularly preferred in the toner of the present invention is a hydrocarbon wax or a petroleum wax obtained by the method.

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

These compounds have relatively low polarities themselves and are considered to stabilize the charge of the toner matrix. It is believed that this further enhances the effect of preventing "retransfer" of the fine particles of the present invention.

Among these compounds, compounds having an endothermic peak at 120 ° C. or lower in differential thermal analysis include polyolefins, hydrocarbon waxes or petroleum waxes or higher alcohols by the Fischer-Tropsch method, and their weight average molecular weights measured by GPC. (Mw)
And the number average molecular weight (Mn) ratio (Mw / Mn) is 1.0
When it is 2.0, the effect of preventing "retransfer" is further enhanced. By adding the wax having a sharp molecular weight distribution (Mw / Mn) of 1.0 to 2.0 to the toner, the magnetic material in the binder resin, charge control in the melt-kneading step in the production of the toner. It is considered that the state of dispersion of the agent and the like is more preferable for the present invention.

In the toner of the present invention, the value of the shape factor SF1 measured by an image analyzer for toner particles is 110 <S.
F1 ≦ 180 (more preferably 120 <SF1 ≦ 16
0), the value of the shape factor SF2 is 110 <SF2 ≦ 140
(More preferably 115 <SF2 ≦ 140), SF2
In the case where the ratio B / A of the value B obtained by subtracting 100 from the value of A and the value A obtained by subtracting 100 from the value of SF1 is 1.0 or less, the effect of preventing "retransfer" is further enhanced. The shape in the above range is a shape in which the toner surface is relatively smooth and has few irregularities. In the case of such a shape, it is considered that the fine particles of the present invention externally added to the toner work more effectively and enhance the effect of preventing “retransfer”.

When SF1 is 110 or less, SF2 is 110 or less, and when the value of B / A exceeds 1.0, it is difficult to clean the transfer residual toner remaining on the latent image carrier. And poor cleaning is likely to occur.

When SF1 exceeds 180, and when SF1
If 2 exceeds 140, the effect of preventing "retransfer" cannot be sufficiently improved.

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

A method of pulverizing using a mechanical impact type pulverizing apparatus or a method of jet pulverization in which the pulverizing pressure is reduced to lower than usual and the number of circulations is increased to perform fine pulverization. In addition, a hot water bath method in which finely pulverized or further classified toner particles are dispersed in water and heated, a heat treatment method in which the toner particles are passed through a hot air flow, and a mechanical impact method in which mechanical energy is applied to treat the toner particles are exemplified. .

Among these, the method of applying treatment by mechanical impact is preferable. Examples of the treatment for applying a mechanical impact force include, for example, a method of applying a mechanical impact force to a toner by a mechanical impact type pulverizer such as a Kryptron system manufactured by Kawasaki Heavy Industries, Ltd. or a turbo mill manufactured by Turbo Industries, Inc., and Hosokawa Micron. Like high-speed rotating blades, the toner is pressed against the inside of the casing by centrifugal force, and applied to the toner by compressive and frictional forces, as in devices such as Mechanofusion System manufactured by Nara Corporation and hybridization systems manufactured by Nara Machinery. There is a method of applying a mechanical impact force.

When the treatment for applying a mechanical impact force is performed after the fine pulverization step of the toner or after the classification step, the effect of preventing "retransfer" is further enhanced, which is particularly preferable. It is also considered that the mechanical impact treatment causes the toner surface to have a “certain unique surface state” in which the action of the fine particles of the present invention is more likely to work.

Examples of the binder resin usable in the present invention include the following. In the case of the toner for heat fixing, for example, polystyrene, poly-p-chlorostyrene, a homopolymer of styrene such as polyvinyltoluene and a substituted product thereof; a styrene-vinylnaphthalene copolymer, a styrene-acrylate 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-
Styrenes 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,
Phenol resin, natural modified phenolic resin, natural resin modified maleic 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 and the like can be used.

Among these, the styrene copolymer is
The effect of preventing "retransfer" is further enhanced, which is particularly preferable.

The resin obtained by the radical polymerization reaction has a relatively low polarity of its own main chain, and is considered to stabilize the charge of the toner matrix. It is believed that this further enhances the effect of preventing "retransfer" of the fine particles of the present invention.

Examples of comonomers for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, and the like.
Such as dodecyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide, etc. Monocarboxylic acid having a heavy bond or a substituted product thereof; acrylic acid such as acrylic acid, methacrylic acid, α-ethylacrylic acid, crotonic acid and α- or β-alkyl derivatives thereof, fumaric acid, maleic acid, citraconic acid Unsaturated dicarboxylic acids and monoester derivatives thereof, maleic anhydride and the like can be used. Such a monomer can be used alone or as a mixture and copolymerized with another monomer to produce a desired polymer.

Among these, it is particularly preferable to use a monoester derivative of an 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.
Monoesters of unsaturated dicarboxylic acids; alkenyl dicarboxylic acids such as monobutyl n-butenylsuccinate, monomethyl n-octenylsuccinate, monoethyl n-butenylmalonate, monomethyl n-dodecenylglutarate, monobutyl n-butenyladipate and the like. Monoesters of aromatic dicarboxylic acids such as monomethyl phthalate, monoethyl phthalate and monobutyl phthalate; vinyls such as vinyl chloride, vinyl acetate and vinyl benzoate Esters, for example, ethylene olefins such as ethylene, propylene, butylene, etc .; for example, vinyl ketones, for example, 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 crosslinking 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 esters having two double bonds such as acrylate, ethylene glycol dimethacrylate, 1,3-butanediol dimethacrylate; divinyl compounds such as divinylaniline, divinyl ether, divinyl sulfide, divinyl sulfone, and three or more Can be used alone or as a mixture.

The toner of the present invention is particularly effective when the magnetic toner contains a magnetic substance in the toner.

The magnetic material contained in the toner of the present invention is preferably an alloy or compound powder containing a ferromagnetic element. Examples of such materials include magnetite, maghemite, ferrite, and the like, and alloys and compounds such as iron, cobalt, nickel, manganese, and zinc, and other ferromagnetic alloys.

[0055] As a BET specific surface area by nitrogen gas adsorption method of the magnetic powder, 1~40m ² / g, more 2～30M ²
/ G is preferred.

The average particle size of the magnetic powder is 0.05 to 1
μm, preferably 0.1 to 0.6 μm.

Further, the magnetic material contains 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, based on parts by mass.

The toner of the present invention is particularly preferable when the toner contains a substantially spherical magnetic substance. In the melt-kneading step in the production, the state of dispersion of the magnetic material in the binder resin is different from the case where the shape of the magnetic material is substantially other than spherical, and a specific surface state is more preferable. It is believed that the effect of preventing "retransfer" of the fine particles further works. When the shape of the magnetic material is “substantially spherical”, the average of the ratio of the major axis to the minor axis (major axis / minor axis) of each particle (100 or more particles measured) is 1. 0
~ 1.2.

In the toner of the present invention, a charge control agent can be used by mixing (internal addition) with the toner particles or by mixing (externally adding) with the toner particles. The charge control agent makes it possible to control the amount of charge optimally according to the development system. In particular, in the present invention, the balance between the particle size distribution and the amount of charge can be further stabilized. Examples of substances that control the toner to be negatively charged include the following substances.

For example, organic metal complexes and chelate compounds are effective, and examples thereof include monoazo metal complexes, acetylacetone metal complexes, aromatic hydroxycarboxylic acids, and aromatic dicarboxylic acid-based 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.

The toner of the present invention preferably has a form in which inorganic fine powder is externally added to the developer.

It is preferable that the inorganic fine powder is contained by stirring and mixing with a developer and a mixer such as a Henschel mixer.

The inorganic fine powder used in the present invention includes:
Inorganic fine powders such as silica fine powder, titanium oxide, and aluminum oxide are preferable, and silica fine powder is particularly preferable. For example, as the fine silica 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. 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 more preferable. In the case of fumed silica, for example, aluminum chloride, titanium chloride, etc.
By using another metal halide compound together with a silicon halide compound, it is possible to obtain a composite fine powder of silica and another metal oxide, and these are included.

Further, a material whose surface has been previously rendered hydrophobic with an organic compound may be used. Examples of such an organic treatment method include a method of treating with an organic metal compound such as a silane coupling agent or a titanium coupling agent that reacts or physically adsorbs with the inorganic fine powder; or a treatment with a silane coupling agent, or a treatment with silane. A method of treating with a coupling agent and treating with an organosilicon compound such as silicone oil at the same time.

[0065] 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 size of the toner is 10.0 μm.
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 latent electrostatic image bearing member or the intermediate transfer member before transfer is further increased.

The method for producing the toner of the present invention includes the following methods. In producing the toner according to the present invention, the above-described constituent materials were mixed using a Henschel mixer, a ball mill, a V-type mixer or other mixer, and a hot kneader such as a hot roll kneader or an extruder. Kneading step, after cooling and solidifying the kneaded material, a pulverizing step using a pulverizer such as a jet mill,
It is preferable to be manufactured through a manufacturing step having at least the above steps. Further, if necessary, it is preferable to go through a classifying step of the pulverized material.

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

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 a preferable state for the present invention, and it is pulverized. Thus, the specific state is exposed to the toner surface as it is, and the effect of preventing "retransfer" of the toner of the present invention is exhibited.

In the present invention, SF-
1. SF-2 is, for example, FE-SEM manufactured by Hitachi, Ltd.
Using (S-800), 100 toner images of 2 μm or more that were enlarged 1000 times were randomly sampled, and the image information was introduced into an image analyzer (Luzex III) manufactured by Nicolet, for example, via an interface and analyzed. And the values calculated from the following equation are used as shape factors SF-1, S
Defined as F-2.

[0071]

(Equation 1)

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

The shape coefficient SF-1 indicates the degree of roundness of the toner particles, and the shape coefficient 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 with a high-precision internal heating type input compensation type differential scanning calorimeter. For example, DSC- manufactured by PerkinElmer, Inc.
7 can be used. The measuring method is ASTM D3418-
Perform according to 82. The DSC curve used in the present invention is:
After raising the temperature once and taking the pre-history, the temperature rate is 10 ° C / mi
n, a DSC curve measured when the temperature is lowered and raised in the temperature range of 0 to 200 ° C. The endothermic peak temperature is
In the DSC curve, a peak temperature in a positive direction, that is, a 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 using a Coulter Counter TA-II or Coulter Multisizer (manufactured by Coulter). The electrolyte is 1
A 1% NaCl aqueous solution is prepared using graded sodium chloride. For example, ISOTONR-II (manufactured by Coulter Scientific Japan) can be used. As a measurement 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 the measurement sample is further added to 2 to 50 ml.
Add 20 mg. The electrolytic solution in which the sample was suspended was subjected to dispersion treatment for about 1 to 3 minutes using an ultrasonic
A volume distribution and a number distribution were calculated by measuring the volume and the number of toner particles having a size of μm or more. Then, the weight-based weight average particle diameter D4 (the median value of each channel is set as a representative value for each channel) obtained from the volume distribution according to the present invention was obtained.

As a method for measuring the charge amount of the fine particles of the present invention, EFV200 / 300 (manufactured by Powder Deck) as a carrier is used in an environment of a temperature of 23 ° C. and a humidity of 60%.
Then, 10.0 g of the carrier and 0.2 g of the fine particles are placed in a polyethylene container having a capacity of 50 ml, and shaken by hand 90 times. Next, about 1 g of the mixture is placed in a metal measuring container 2 having a 500-mesh screen 3 at the bottom as shown in FIG. At this time, the weight of the entire measurement container 2 is measured and is defined as W1 (g). Next, it is placed on a suction machine (the part in contact with the measurement container 2 is an insulator), and suction is performed from the suction port 7 at a pressure of 2450 Pa (250 mmAq).
In this state, suction is performed for 2 minutes to remove fine particles. The potential of the electrometer 9 at this time is set to V (volt). Here, 8 is a capacitor whose capacity is C (mF).
The weight of the whole measuring container 2 after suction is measured,
(G). The charge amount T (mC / kg) of the fine particles is obtained by the above formula of charge amount T (mC / kg) = C × V / (W1−W2).

[0077]

EXAMPLES The present invention will be described below in more detail with reference to Examples, which should not be construed as limiting the present invention.

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 controlling agent) 2 parts by mass Low molecular weight polyethylene (endothermic peak of differential thermal analysis: 102 ° C., Mw / Mn: 1.3) 4 parts by mass After pre-mixing the above materials, a biaxial kneading extruder set at 130 ° C. To perform melt-kneading. After cooling the kneaded material, it was coarsely pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier. Further, the surface was treated by mechanical impact to obtain a black powder toner base A.

The fine black powder A: 100 parts by mass, melamine-formaldehyde resin particles (average particle diameter:
0.33 μm, charge amount: +36 mC / kg): 0.1 parts by mass, and hexamethyldisilazane / dimethylsilicone oil-treated dry silica: 1.2 parts by mass with a Henschel mixer 10B at 3200 rpm for 2 minutes with stirring and mixing. I got

The weight average particle diameter of the obtained toner is 6.9 μm.
m, SF1 was 144, and SF2 was 126. Also,
The endothermic peak in the differential thermal analysis was at 102 ° C.

When the surface of the toner was observed with an electron microscope, it was found that the fine particles a were adhered to the surface of the toner particles as they were and were not embedded in the surface.

(Examples 2 to 4 and Comparative Example 1) Same as Example 1 except that the fine particles added in Example 1 were fine particles be composed of a polymer compound containing a nitrogen atom shown in Table 1. Thus, a toner shown in Table 6 was obtained.

(Examples 5 to 7) Toners shown in Table 6 were obtained in the same manner as in Example 1 except that the amount of the fine particles a added in Example 1 was changed to the amount shown in Table 6.

(Examples 8 to 14) The same procedures as in Example 1 were carried out except that the substances shown in Table 5 were added instead of the low-molecular-weight polyethylene added in Example 1, to obtain toner bases B to
H was obtained, and the other conditions were the same as in Example 1 to obtain toners shown in Table 6.

(Examples 15 to 17) The same procedures as in Example 1 were carried out except that the mechanical impact treatment performed in Example 1 was not performed, and the shape shown in Table 5 was adjusted by adjusting the conditions of the mechanical impact treatment. In the same manner, toner bases I to K were obtained, and the other conditions were the same as in Example 1 to obtain toners shown in Table 6.

Examples 18 and 19 and Comparative Example 2 In the same manner as in Example 1 except that the fine particles added in Example 1 were fine particles f to h made of a polymer containing a methyl methacrylate unit shown in Table 2, The toner shown in Table 7 was obtained.

(Examples 20 to 22) Toners shown in Table 7 were obtained in the same manner as in Example 1 except that the amount of the fine particles f added in Example 1 was changed to the amount shown in Table 7.

Examples 23 to 32 Toners shown in Table 7 were obtained in the same manner as in Example 1 except that the fine particles f were added to the toner bases B to K shown in Table 5.

Examples 33 to 35 The toners shown in Table 8 were produced in the same manner as in Example 1 except that the fine particles added in Example 1 were fine particles ik of stearic acid or a metal salt thereof shown in Table 3. I got

Examples 36 to 38 Toners were obtained in the same manner as in Example 1 except that the amount of the fine particles i to be added was changed to the amount shown in Table 8.

(Examples 39 to 48) Toners shown in Table 8 were obtained in the same manner as in Example 1 except that the fine particles i were added to the toner bases B to K shown in Table 5.

Examples 49 and 50 Toners shown in Table 9 were obtained in the same manner as in Example 1 except that the fine particles 1 and m made of a phenol resin shown in Table 4 were added.

(Examples 51 to 53) A toner was obtained in the same manner as in Example 1 except that the amount of the fine particles 1 to be added was changed to the amount shown in Table 9.

(Examples 54 to 63) Toners shown in Table 9 were obtained in the same manner as in Example 1 except that the fine particles 1 were added to the toner bases B to K shown in Table 5.

Comparative Example 3 Polyester resin (condensed 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 controlling 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 pre-mixing the above materials, a biaxial kneading extruder set at 130 ° C. To perform melt-kneading. After cooling the kneaded material, it was coarsely pulverized, finely pulverized by a pulverizer using a jet stream, and further classified using an air classifier to obtain a black powder toner base L.

To 100 parts by mass of the above black fine powder L, 0.4 parts by mass of dry silica treated with hexamethyldisilazane / dimethyl silicone oil: stirred and mixed at 3200 rpm for 2 minutes with a Henschel mixer 10B to obtain a toner. .

The weight average particle size of the obtained toner is 11.3.
μm, SF1 was 160, and SF2 was 154. The endothermic peak in differential thermal analysis was at 145 ° C.

<Evaluation> The toners of the above Examples and Comparative Examples were each evaluated by the following methods. Table 6-
The results are shown in FIG.

1) Evaluation of transferability Laser beam printer LBP-1260 manufactured by Canon
Using a device equipped with a variable transfer bias power supply and developing a solid black image in an environment of 23 ° C./60% RH,
The image was transferred onto a transfer paper of 75 g / m ² , and the transfer residual image remaining on the photoreceptor was peeled off with a transparent polyester adhesive tape and pasted on white paper. The reflection density was measured with a Macbeth reflection densitometer, and was used as a standard. The density of the portion where only the tape was stuck on the white paper was evaluated by subtracting the density therefrom. The transfer voltage was evaluated in increments of 0.5 kV from 1.0 to 3.0 kV.

2) Evaluation of Image Density Canon Laser Beam Printer LBP-1260
After printing 2,000 sheets in an environment of 32 ° C./80% using the above method, the apparatus was allowed to stand for 2 days, then a solid black image was printed, and the image density was measured and evaluated using a Macbeth reflection densitometer.

[0101]

[Table 1]

[0102]

[Table 2]

[0103]

[Table 3]

[0104]

[Table 4]

[0105]

[Table 5]

[0106]

[Table 6]

[0107]

[Table 7]

[0108]

[Table 8]

[0109]

[Table 9]

[0110]

[Table 10]

[0111]

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

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an apparatus for measuring a charge amount of a toner of the present invention.

──────────────────────────────────────────────────の Continuation of the front page (51) Int.Cl. ⁶ Identification number Agency reference number FI Technical indication G03G 9/08 361 365 381 (72) Inventor Yuki Karaki 3-chome 30-30 Shimomaruko, Ota-ku, Tokyo Inside Canon Inc.

Claims (82)

[Claims] 1. A method of externally adding fine particles having a mean particle diameter of 0.05 to 2.0 μm comprising a polymer compound containing a nitrogen atom to toner base particles, and having an endothermic peak of 120 ° C. or less in differential thermal analysis. A negatively chargeable toner comprising at least one. 2. The negatively chargeable toner according to claim 1, wherein the fine particles comprising the nitrogen-containing polymer compound have an average particle size of 0.1 to 1.0 μm. 3. The negatively charged toner according to claim 1, wherein the fine particles comprising the nitrogen-containing polymer compound are contained in the toner in an amount of 0.01 to 0.3 parts by mass. Toner. 4. The polymer compound containing a nitrogen atom,
The negatively chargeable toner according to any one of claims 1 to 3, comprising a melamine-formaldehyde resin or a benzoguanamine-formaldehyde resin. 5. The negatively chargeable toner according to claim 1, wherein the fine particles made of a polymer compound containing a nitrogen atom have a positive chargeability. 6. The negatively chargeable toner according to claim 1, wherein the toner has one or more endothermic peaks in differential thermal analysis at 60 ° C. to 120 ° C. 7. The negatively chargeable toner according to claim 6, wherein the toner has one or more endothermic peaks in differential thermal analysis at 70 ° C. or higher. 8. The negatively chargeable toner according to claim 6, wherein the toner has one or more endothermic peaks in differential thermal analysis at 110 ° C. or lower. 9. The negatively chargeable toner according to claim 1, wherein the toner contains a polyolefin, a hydrocarbon wax, a petroleum wax, or a higher alcohol obtained by a Fischer-Tropsch method. 10. The negatively chargeable toner according to claim 1, wherein the toner contains a polyolefin or a hydrocarbon wax or a petroleum wax obtained by a Fischer-Tropsch method. 11. The Mw / Mn of the polyolefin, hydrocarbon wax, petroleum wax or higher alcohol measured by GPC according to Fischer-Tropsch method, which is contained in the toner, is 1.0 to 2.0. The negatively chargeable toner according to claim 1. 12. The value of the shape factor SF1 measured by an image analyzer of the toner particles is 110 <SF1 ≦ 180, the value of the shape factor SF2 is 110 <SF2 ≦ 140, and 100 is subtracted from the value of SF2. The negatively chargeable toner according to any one of claims 1 to 11, wherein a ratio B / A of the calculated value B and a value A obtained by subtracting 100 from the value of SF1 is 1.0 or less. 13. The toner according to claim 1, wherein the shape factor SF1 measured by an image analyzer of the toner particles is 120 <SF1 ≦ 160, and the shape factor SF2 is 115 <SF2 ≦ 140. 13. The negatively chargeable toner according to any one of items 1 to 12. 14. A toner according to claim 1, wherein a styrene copolymer is used as a binder resin of said toner.
The negatively chargeable toner according to any one of the above. 15. The negatively chargeable toner according to claim 1, wherein a magnetic material is contained in the toner. 16. The negatively chargeable toner according to claim 15, wherein the magnetic substance in the toner is a magnetic iron oxide having a substantially spherical shape. 17. A toner having a weight average particle diameter of 10.0 μm.
17. The negatively chargeable toner according to claim 1, wherein m is equal to or less than m. 18. The toner has a weight average particle diameter of 8.0 μm.
The negatively chargeable toner according to claim 1, wherein: 19. The method for producing a toner according to claim 1, further comprising a step of melt-kneading the binder resin and the other composition and a step of pulverizing the same.
The negatively chargeable toner according to any one of the above. 20. The negatively chargeable toner according to claim 19, wherein at least a process of applying a mechanical impact force is performed in the process of producing the toner. 21. The negatively chargeable toner according to claim 19, wherein a process of applying a mechanical impact force is performed after the fine pulverizing step in the toner manufacturing process. 22. Fine particles of a polymer containing methyl methacrylate units having an average particle size of 0.05 to 2.0 μm are externally added to the toner base particles, and the endothermic peak in the differential thermal analysis is less than 120 ° C. A negatively chargeable toner characterized by having the above. 23. The fine particles comprising a polymer containing a methyl methacrylate unit have an average particle size of 0.1 to 1.0 μm.
23. The negatively chargeable toner according to claim 22, wherein 24. The toner according to claim 22, wherein the fine particles comprising the polymer containing methyl methacrylate units are contained in the toner in an amount of 0.01 to 0.3 parts by mass.
3. The negatively chargeable toner according to item 3. 25. The negatively chargeable toner according to claim 22, wherein the fine particles comprising a polymer containing a methyl methacrylate unit have a positive chargeability. 26. The negatively chargeable toner according to claim 22, wherein the toner has one or more endothermic peaks in differential thermal analysis at 60 ° C. to 120 ° C. 27. The negatively chargeable toner according to claim 26, wherein the toner has one or more endothermic peaks in differential thermal analysis at 70 ° C. or higher. 28. The negatively chargeable toner according to claim 26, wherein the toner has one or more endothermic peaks in differential thermal analysis at 110 ° C. or lower. 29. The negatively chargeable toner according to claim 22, wherein the toner contains a polyolefin, a hydrocarbon wax, a petroleum wax, or a higher alcohol obtained by Fischer-Tropsch method. 30. The negatively chargeable toner according to claim 22, wherein the toner contains a polyolefin or a hydrocarbon wax or a petroleum wax obtained by a Fischer-Tropsch method. 31. The Mw / Mn of the polyolefin, hydrocarbon wax, petroleum wax or higher alcohol contained in the toner, as measured by GPC, of 1.0 to 2.0. The negatively chargeable toner according to any one of claims 22 to 30, wherein 32. The value of the shape factor SF1 measured by an image analyzer of the toner particles is 110 <SF1 ≦ 180, the value of the shape factor SF2 is 110 <SF2 ≦ 140, and 100 is subtracted from the value of SF2. 32. The negatively chargeable toner according to claim 22, wherein a ratio B / A of the calculated value B and a value A obtained by subtracting 100 from the value of SF1 is 1.0 or less. 33. The toner according to claim 22, wherein the value of the shape factor SF1 measured by the image analyzer of the toner particles is 120 <SF1 ≦ 160, and the value of the shape factor SF2 is 115 <SF2 ≦ 140. 33. The negatively chargeable toner as described in any one of the above items. 34. A toner according to claim 22, wherein a styrene copolymer is used as a binder resin of said toner.
3. The negatively chargeable toner according to any one of 3. 35. The negatively chargeable toner according to claim 22, wherein a magnetic material is contained in the toner. 36. The negatively chargeable toner according to claim 35, wherein the magnetic substance in the toner is magnetic iron oxide having a substantially spherical shape. 37. The toner has a weight average particle diameter of 10.0 μm.
The negatively chargeable toner according to any one of claims 22 to 36, wherein m is equal to or less than m. 38. The toner has a weight average particle diameter of 8.0 μm.
The negatively chargeable toner according to any one of claims 22 to 36, wherein: 39. The method according to claim 22, wherein the step of producing the toner includes at least a step of melt-kneading the binder resin and the other composition and a step of pulverizing the same.
8. The negatively chargeable toner according to any one of 8. 40. The negatively chargeable toner according to claim 39, wherein at least a process of applying a mechanical impact force is performed in the process of producing the toner. 41. The negatively chargeable toner according to claim 39, wherein a treatment for applying a mechanical impact force is performed after the fine pulverization step in the toner production process. 42. The fatty acid compound having an average particle size of 0.1.
A negatively chargeable toner characterized in that fine particles having a particle size of from 0.5 to 2.0 μm are externally added to toner base particles, and that one or more endothermic peaks in differential thermal analysis are present at 120 ° C. or lower. 43. The negatively chargeable toner according to claim 42, wherein the fine particles comprising the fatty acid compound have an average particle size of 0.1 to 1.0 μm. 44. The negatively chargeable toner according to claim 42, wherein the fine particles comprising the fatty acid compound are contained in the toner in an amount of 0.05 to 1.0 part by mass. 45. The negatively chargeable toner according to claim 42, wherein the fatty acid compound is a metal salt of a fatty acid. 46. The negatively chargeable toner according to claim 42, wherein the fine particles comprising the fatty acid compound have a positive chargeability. 47. The negatively chargeable toner according to claim 42, wherein the toner has one or more endothermic peaks in differential thermal analysis at 60 ° C. to 120 ° C. 48. The negatively chargeable toner according to claim 47, wherein the toner has one or more endothermic peaks in differential thermal analysis at 70 ° C. or higher. 49. The negatively chargeable toner according to claim 47, wherein the toner has one or more endothermic peaks in differential thermal analysis at 110 ° C. or lower. 50. The negatively chargeable toner according to claim 42, wherein the toner contains a polyolefin, a hydrocarbon wax, a petroleum wax, or a higher alcohol by a Fischer-Tropsch method. 51. The negatively chargeable toner according to claim 42, wherein the toner contains a polyolefin or a hydrocarbon wax or a petroleum wax obtained by a Fischer-Tropsch method. 52. The Mw / Mn of the polyolefin, hydrocarbon wax, petroleum wax or higher alcohol measured by GPC of the polyolefin, the Fischer-Tropsch method contained in the toner is 1.0 to 2.0. The negatively chargeable toner according to any one of claims 42 to 51. 53. The value of the shape factor SF1 measured by the image analyzer of the toner particles is 110 <SF1 ≦ 180, the value of the shape factor SF2 is 110 <SF2 ≦ 140, and 100 is subtracted from the value of SF2. 53. The negatively chargeable toner according to claim 42, wherein a ratio B / A of the calculated value B and a value A obtained by subtracting 100 from the value of SF1 is 1.0 or less. 54. The toner according to claim 42, wherein the value of the shape factor SF1 measured by the image analyzer of the toner particles is 120 <SF1 ≦ 160, and the value of the shape factor SF2 is 115 <SF2 ≦ 140. 54. The negatively chargeable toner according to any one of the above items. 55. A toner according to claim 42, wherein a styrene copolymer is used as a binder resin of said toner.
5. The negatively chargeable toner according to any one of 4. 56. The negatively chargeable toner according to claim 42, wherein a magnetic material is contained in the toner. 57. The negatively chargeable toner according to claim 56, wherein the magnetic substance in the toner is a magnetic iron oxide having a substantially spherical shape. 58. The toner has a weight average particle diameter of 10.0 μm.
The negatively chargeable toner according to any one of claims 42 to 57, wherein m is equal to or less than m. 59. The toner has a weight average particle size of 8.0 μm.
The negatively chargeable toner according to any one of claims 42 to 57, wherein: 60. The method for producing a toner according to claim 42, wherein at least a step of melt-kneading the binder resin and the other composition and a step of pulverizing the same are included.
9. The negatively chargeable toner according to any one of items 9 to 9. 61. The negatively chargeable toner according to claim 60, wherein at least a process of applying a mechanical impact force is performed in the toner manufacturing process. 62. The negatively chargeable toner according to claim 60, wherein a process of applying a mechanical impact force is performed after the fine pulverizing step in the toner manufacturing process. 63. A method in which fine particles of a phenol resin having an average particle diameter of 0.05 to 2.0 μm are externally added to toner base particles, and one or more endothermic peaks in differential thermal analysis are at 120 ° C. or lower. Negatively chargeable toner. 64. The negatively chargeable toner according to claim 63, wherein the fine particles made of the phenol resin have an average particle size of 0.1 to 1.0 μm. 65. The fine particles comprising the phenol resin,
65. The negatively chargeable toner according to claim 63 or 64, wherein 0.05 to 1.0 parts by mass is contained in the toner. 66. The fine particles comprising the phenol resin,
66. A positively chargeable material.
The negatively chargeable toner according to any one of the above. 67. The negatively chargeable toner according to claim 63, wherein the toner has one or more endothermic peaks in differential thermal analysis at 60 ° C. to 120 ° C. 68. The negatively chargeable toner according to claim 67, wherein the toner has one or more endothermic peaks in differential thermal analysis at 70 ° C. or higher. 69. The negatively chargeable toner according to claim 67, wherein the toner has one or more endothermic peaks in differential thermal analysis at 110 ° C. or lower. 70. The negatively chargeable toner according to claim 63, wherein the toner contains a polyolefin, a hydrocarbon wax obtained by Fischer-Tropsch method, a petroleum wax, or a higher alcohol. 71. The negatively chargeable toner according to claim 63, wherein the toner contains a polyolefin or a hydrocarbon wax or a petroleum wax obtained by a Fischer-Tropsch method. 72. The Mw / Mn of the polyolefin, hydrocarbon wax, petroleum wax or higher alcohol measured by GPC of the polyolefin or the Fischer-Tropsch method contained in the toner is 1.0 to 2.0. 73. The negatively chargeable toner according to any one of claims 63 to 71. 73. The value of the shape factor SF1 measured by the image analyzer of the toner particles is 110 <SF1 ≦ 180, the value of the shape factor SF2 is 110 <SF2 ≦ 140, and 100 is subtracted from the value of SF2. 73. The negatively chargeable toner according to any one of claims 63 to 72, wherein a ratio B / A of the calculated value B and a value A obtained by subtracting 100 from the value of SF1 is 1.0 or less. 74. The toner according to claim 63, wherein the value of the shape factor SF1 measured by the image analyzer of the toner particles is 120 <SF1 ≦ 160, and the value of the shape factor SF2 is 115 <SF2 ≦ 140. 74. The negatively chargeable toner according to any one of the above items. 75. A styrene-based copolymer is used as a binder resin of the toner.
5. The negatively chargeable toner according to any one of 4. 76. The negatively chargeable toner according to claim 63, wherein a magnetic material is contained in the toner. 77. The negatively chargeable toner according to claim 76, wherein the magnetic substance in the toner is magnetic iron oxide having a substantially spherical shape. 78. The toner has a weight average particle diameter of 10.0 μm.
The negatively chargeable toner according to any one of claims 63 to 77, wherein m is equal to or less than m. 79. The toner has a weight average particle size of 8.0 μm.
The negatively chargeable toner according to any one of claims 63 to 77, wherein: 80. The toner production process according to claim 63, further comprising a step of melting and kneading at least a binder resin and another composition and a step of pulverizing the composition.
The negatively chargeable toner according to any one of the above. 81. The negatively chargeable toner according to claim 80, wherein at least a process of applying a mechanical impact force is performed in the toner manufacturing process. 82. The negatively chargeable toner according to claim 80, wherein a treatment for applying a mechanical impact force is performed after the fine pulverization step in the toner production process.