JPH1010771A - Electrostatic latent image developing toner and electrostatic latent image developer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an excellent fluidity and to avoid a problem of toner fume by specifying the angle of slide, volume average particle size and loose apparent specific gravity of a toner. SOLUTION: The electrostatic latent image developing toner which contains toner particles containing a coloring agent and a binder resin has the angle of slide X ( deg.), volume average particle size D50 (μm) and loose apparent specific gravity AD(g/cc) satisfying the conditions of AD=(-0.005X+k1 )×(D50 /8.5)<1/2> , wherein k1 =0.57 to 0.64, AD=k2 ×(D50 )<1/2> , wherein k2 is 0.135 to 0.158, and X=28 deg. to 38 deg. and D50 =3 to 10μm. The loose apparent specific gravity and the angle of slide are controlled by using at least two kinds of inorg. fine particles to externally add to the toner particles and by selecting the kinds of these particles. A first inorg. fine particles have 10 to 30nm number average particle size of the primary particle size, while the second inorg. fine particles have 100 to 1000nm particle size.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] 1. Field of the Invention [0002] The present invention relates to a toner for developing an electrostatic latent image formed on an electrostatic latent image carrier and a developer using the toner.

[0002]

2. Description of the Related Art Conventionally, an electrostatic latent image formed on an electrostatic latent image carrier such as a photosensitive member is developed using toner, and the toner image is transferred onto a recording member such as recording paper. The forming method is widely used in copiers, printers, facsimile machines and the like, and has recently been adopted in full-color image forming apparatuses that reproduce a multicolor image by superimposing a plurality of color toners.

In such an image forming apparatus, an area gradation method and a laser intensity modulation method are employed for reproducing a multi-gradation image. Also, high fluidity is required for the toner.However, especially in the laser intensity modulation method, gradation reproduction is performed by changing the toner adhesion amount corresponding to the change in the charge amount of the latent image due to laser intensity modulation, so higher fluidity is required. is necessary.

In order to improve the fluidity, it is effective to externally add inorganic fine particles such as silica fine particles to the toner as a fluidizing agent to increase the amount of the fine particles. Due to the high fluidity of the toner having high fluidity, the toner tends to fly in the developing device or in the developing area during printing, and the problem of toner dust occurs. It is effective to increase the charge amount of the toner in order to prevent toner fumes, but with such a toner, the developability is reduced and the problem of image density reduction is caused, particularly in a low-temperature and low-humidity environment. . In order to improve the developability, it is necessary to further increase the fluidity of the toner. Therefore, in the end of these methods, only one of the characteristics is used in an insufficient balance, and the above-mentioned characteristics are used. It could not be solved fundamentally.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide an electrostatic latent image developing toner and an electrostatic latent image developer which solve the above-mentioned problems. That is, an object of the present invention is to provide an electrostatic latent image developing toner and an electrostatic latent image developer which are excellent in fluidity and do not cause a problem of toner dust. Another object of the present invention is to provide an electrostatic latent image developing toner and an electrostatic latent image developer in which toner fumes and fogging do not occur even when printing is performed and the developer life is improved. . Another object of the present invention is to provide an electrostatic latent image developing toner and an electrostatic latent image developer having a stable toner charge amount even in a high-temperature, high-humidity environment and a low-temperature, low-humidity environment.
Another object of the present invention is to provide an electrostatic latent image developing toner and an electrostatic latent image developer suitable for full-color image formation.

[0006]

SUMMARY OF THE INVENTION The present invention relates to a toner for developing an electrostatic latent image containing toner particles containing a colorant and a binder resin.
(°), volume average particle diameter D ₅₀ (μm) and loose apparent specific gravity AD (g / cc) are as follows: (1) to (6): AD = (− 0.005X + k ₁ ) × (D ₅₀ /8.5) ) ^1/2 (1) k ₁ = 0.57 to 0.64 (2) AD = k ₂ × (D ₅₀ ) ^1/2 (3) k 2 = 0.135 to 0.158 (4) X = 28 ° ~38 ° (5) relates to a toner for developing an electrostatic latent image which satisfies the condition represented by D ₅₀ = 3~10μm (6).

Further, the present invention provides an electrostatic latent image developer comprising a toner comprising toner particles containing a colorant and a binder resin, an external additive attached to the toner particle surface, and a magnetic carrier. Angle of repose X of this toner
(°), volume average particle diameter D ₅₀ (μm) and loose apparent specific gravity AD (g / cc) are as follows: (1) to (6): AD = (− 0.005X + k ₁ ) × (D ₅₀ /8.5) ) ^1/2 (1) k ₁ = 0.57 to 0.64 (2) AD = k ₂ × (D ₅₀ ) ^1/2 (3) k ₂ = 0.135 to 0.158 (4) X = 28 ° ~38 ° (5) to an electrostatic latent image developer that satisfies the condition indicated by D ₅₀ = 3~10μm (6).

[0008]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention solves the above-mentioned problem by setting the angle of repose, the volume average particle diameter, and the loose apparent specific gravity of the toner to have a specific relationship.

The present inventors have conducted intensive studies on the problem of scattering and fogging of toner having high fluidity by adding an external additive, and found that the fluidity of the toner can be increased if the apparent specific gravity is controlled to a predetermined range. The present invention has been found to be able to impart fluidity, and even to a toner having such a high fluidity, if the angle of repose is controlled within a range larger than usual, the problem of toner scattering and fogging can be solved. is there.

The toner of the present invention has a repose angle X (°), a volume average particle diameter D ₅₀ (μm), and a loose apparent specific gravity AD (g / g).
cc) is the following (1) to (6): AD = (− 0.005X + k ₁ ) × (D ₅₀ /8.5) ^1/2 (1) k ₁ = 0.57 to 0.64 (2) AD = K ₂ × (D ₅₀ ) ^1/2 (3) k ₂ = 0.135 to 0.158 (4) X = 28 ° to 38 ° (5) D ₅₀ = 3 to 10 μm (6) To be satisfied. With the toner having such characteristics, it is possible to achieve both high fluidity and the elimination of problems such as toner dust without causing any new problems.

In the formula (1), if k ₁ is smaller than 0.57, it is difficult to achieve both high fluidity and the elimination of problems such as toner dust, and if k ₁ is larger than 0.64, a halftone image is reproduced. This causes problems such as a reduction in toner properties, adhesion of toner components to the photoreceptor, and fogging accompanying printing durability. From such a viewpoint, a preferable range of k ₁ is 0.57
5 to 0.63. If the angle of repose X is smaller than 28 °, problems such as toner dust and fogging cannot be sufficiently solved, and if it is larger than 38 °, tone reproducibility decreases and reproducibility of a halftone image decreases. . From such a viewpoint, the preferable range of the angle of repose is 29 to 37 °, more preferably 30 to 36 °.

In the equation (3), k ₂ is 0.13
If it is smaller than 5, the developability in a low-temperature and low-humidity environment is deteriorated, and the image quality is deteriorated. If it is larger than 0.158, a large amount of a fluidizing agent needs to be added. The problem is that the toner adheres to the nucleus and causes other toner components to adhere, and that the fluidizing agent adheres (spent) to the carrier surface during printing, resulting in a decrease in the chargeability of the carrier. Cause. The preferred range of k ₂ from this point of view 0.138 to 0.
156, more preferably 0.141 to 0.155.

When the volume average particle size is larger than 10 μm, it is not preferable because it is disadvantageous for reproducing a high-definition image. When the volume average particle size is smaller than 3 μm, handling (cleaning, charge amount control) in the image forming apparatus becomes difficult. Therefore, it is not preferable.

The above equations are obtained by correcting the relationship between the loose apparent specific gravity and the angle of repose obtained based on the experimental results described later from the relationship with the toner particle size.

In the present invention, in order to control the loose apparent specific gravity and the angle of repose within the above-mentioned ranges, it can be controlled by using at least two types of inorganic fine particles externally added to the toner particles and selecting the type. . Hereinafter, preferred combinations of the negatively chargeable toner will be described, but the present invention is not limited thereto.

The most preferable form of the negatively charged toner is a form in which first and second inorganic fine particles described below are externally added to negatively charged toner particles.

The first inorganic fine particles are inorganic fine particles whose primary particles have a number average particle diameter of 10 to 30 nm, and are effective in the present invention for controlling the loose apparent specific gravity in the above-mentioned range. High fluidity can be imparted to the toner by mixing and adding such inorganic fine particles to the toner particles. If the average particle size is smaller than 10 nm, the inorganic fine particles are easily embedded in the toner particles, and the powder characteristics of the toner are easily changed. If the average particle size is larger than 30 nm, the effect of improving the fluidity is reduced, which is not preferable.

Further, it is preferable to use the first inorganic fine particles having a negative chargeability with respect to the negatively charged toner particles. This has the function of improving the negative chargeability of the toner, the uniformity (adhesion) of the processing of the second inorganic fine particles to the toner particles described later, and the function of sufficiently exerting the effect of the addition of the second inorganic fine particles.

The amount of the first inorganic fine particles to be added to the toner particles is 0.3 to 3.0% by weight, preferably 0.5 to 2.
It is 5% by weight, more preferably 0.8 to 2.0% by weight. If the amount is less than 0.3% by weight, the effect of the above-mentioned addition is insufficient. If the amount is more than 3% by weight, toner scattering or fogging is liable to occur during printing, and there is a problem that toner components adhere to the photoreceptor. Also occurs.

The first inorganic fine particles are preferably surface-treated with a hydrophobizing agent.
It is desirable to use one having 0 or more. By using the inorganic fine particles thus hydrophobized, it is possible to prevent the toner charge amount from lowering even at high temperature and high humidity.

The degree of hydrophobicity in the present invention is measured by a methanol wettability method. First, methanol is dropped into water in which a sample is dispersed, and the weight of methanol required to wet the entire sample is measured. The percentage of the weight of methanol in water and methanol at this time was defined as the degree of hydrophobicity.

As a hydrophobizing agent for treating the surface of the inorganic fine particles, a silane coupling agent, a titanate coupling agent, a silicone oil, a silicone varnish and the like can be used. Examples of the silane coupling agent include hexamethyldisilazane, trimethylsilane, trimethylchlorosilane, dimethyldichlorosilane, methyltrichlorosilane, allyldimethylchlorosilane, benzyldimethylchlorosilane, methyltrimethoxysilane, methyltriethoxysilane, and isobutyl Trimethoxysilane, dimethyldimethoxysilane, dimethyldiethoxysilane, trimethylmethoxysilane, hydroxypropyltrimethoxysilane, phenyltrimethoxysilane, n
-Butyltrimethoxysilane, n-hexadecyltrimethoxysilane, n-octadecyltrimethoxysilane,
Vinyl trimethoxy silane, vinyl triethoxy silane, γ-methacryloxypropyl trimethoxy silane, vinyl triacetoxy silane, etc. can be used,
As the silicone oil, for example, dimethylpolysiloxane, methylhydrogenpolysiloxane, methylphenylpolysiloxane and the like can be used.

For the surface treatment of the inorganic fine particles with the above-mentioned hydrophobizing agent, for example, the hydrophobizing agent is diluted with a solvent, the above-mentioned diluent is added to the inorganic fine particles and mixed, and the mixture is heated and dried, and then crushed. A dry method, a wet method of dispersing inorganic fine particles in an aqueous system to form a slurry, adding and mixing a hydrophobizing agent, heating and drying, and then disintegrating the resulting mixture can be used.

As such first inorganic fine particles, silica, titania, alumina and the like can be used alone or in combination of two or more, and silica and titania are preferable.

The second inorganic fine particles have a number average particle diameter of 100 to 1000 nm, preferably 100 to 800 nm.
Is used. By using such second inorganic fine particles in combination, it is possible to increase the angle of repose while maintaining high fluidity due to the addition of the first inorganic fine particles. The life of the agent can be extended. Although the reason for this has not been clearly elucidated, the above-mentioned second inorganic fine particles adhere to the surface of the negatively charged toner particles due to the influence of the particle size and the like, so that electrostatic coupling between toner particles is caused. It is probable that the angle of repose was increased due to this. In addition, although the apparent apparent specific gravity tends to decrease as the repose angle of the toner increases, a toner having a large repose angle and a large apparent apparent specific gravity can be obtained by selecting a combination of the first inorganic fine particles and the second inorganic fine particles. It is considered something. If the average particle diameter of the second inorganic fine particles is smaller than 100 nm, the effect of increasing the angle of repose becomes insufficient, and
When the size is larger, the above-mentioned effects become insufficient due to a decrease in the coating amount and adhesion to the toner particles, or when the image formation is repeatedly performed, the pressure is applied by the transfer drum at the time of blade cleaning or in a full-color image forming apparatus or the like. The photoreceptor is easily damaged during transfer.

From the above-mentioned viewpoint, it is preferable to use the second inorganic fine particles having a charge property on the positive side with respect to the negatively chargeable toner particles, and when using as a two-component developer, the second inorganic fine particles. It is preferable that the fine particles have a more positive charge property than the carrier particles. By using such second inorganic fine particles, even when an external additive is spent on the carrier during printing, the second inorganic fine particles have a charge property of negatively charging the toner particles. It is considered that toner dust and fog are eliminated based on the decrease in the amount, and the life of the developer is extended. The second inorganic fine particles are preferably mixed after the first inorganic fine particles are mixed with the toner particles.

Further, since the second inorganic fine particles have a function of reducing the amount of the first inorganic fine particles that pass through the blade during blade cleaning, these fine particles pass through the blade and adhere to the photoreceptor. It is also possible to solve the problem that the components are attached to cause image noise.

Examples of the second inorganic fine particles include fine particles of silica, titania, alumina, barium titanate, magnesium titanate, calcium titanate, strontium titanate, chromium oxide, cerium oxide, magnesium oxide, zirconium oxide and the like. They can be used alone or in combination. These fine particles may be surface-treated with, for example, an aminosilane coupling agent or aminosilicone oil to adjust the chargeability. Second
Since the inorganic fine particles have a number average particle size of 100 to 1000 nm and are relatively large, they exist as primary particles and have an average particle size in the above range. (Aggregate) having an average particle size in the above range, or a mixture of primary particles and aggregates of primary particles and having an average particle size in the above range. Further, as the second inorganic fine particles, the above-mentioned strontium titanate having chargeability is preferable, and particularly, the number average particle diameter is 100 to 800 nm and 1000.
Strontium titanate fine particles in which the content of particles having a size of at least nm is 20% by number or less are preferable.

The second inorganic fine particles are used in an amount of 0.
3 to 5.0% by weight, preferably 0.5 to 3.0% by weight is added. If the amount is less than 0.3% by weight, the above effect is insufficient. If the amount is more than 5% by weight, the effect on the chargeability of the toner is undesirably increased.

Although the preferred embodiments of the first and second inorganic fine particles for the negatively charged toner particles have been described above, the present invention is not limited to these. Further, in addition to the above-described first and second inorganic fine particles, the following third inorganic fine particles are preferably added to the negatively chargeable toner particles for full color from the viewpoint of environmental stability.

As the third inorganic fine particles, inorganic fine particles having a number average particle diameter of primary particles of 30 to 90 nm, preferably 35 to 80 nm are used. Such inorganic fine particles are environmentally stable (especially preventing image density reduction under low temperature and low humidity environment).
Has the function of improving It is also preferable that the first inorganic fine particles can be prevented or reduced from being buried in the toner particles during printing. When the average particle diameter is larger than 90 nm, the above-described effect tends to be insufficient because the coverage ratio of the toner becomes small. Even when the average particle diameter is smaller than 30 nm, the particles may not be formed due to the stirring stress in the developing device during printing use. It is not preferable because it is easily embedded in the particles.

Examples of the third inorganic fine particles include fine particles of silica, titania, alumina, barium titanate, magnesium titanate, calcium titanate, strontium titanate, chromium oxide, cerium oxide, magnesium oxide, zirconium oxide, and the like. Although they can be used alone or in combination of two or more, it is particularly preferable to use titania fine particles from the viewpoint of improving environmental stability. As the titania fine particles, anatase titania, rutile titania, amorphous titania and the like can be used, and anatase titania is preferable.

The third inorganic fine particles are preferably surface-treated with a hydrophobizing agent.
It is desirable to use one having 0 or more. By using the third inorganic fine particles thus hydrophobized, environmental stability can be further improved. When titania fine particles are used as the third inorganic fine particles and subjected to a hydrophobic treatment, the hydrophobic treatment is performed in an aqueous system from the viewpoint of uniformity of the surface treatment of the hydrophobizing agent with respect to titania, prevention of aggregation of the titania particles, and the like. Is preferred.

The amount of the third inorganic fine particles added to the toner particles is 0.1 to 3.0% by weight, preferably 0.3 to 2.0% by weight.
0% by weight. If the amount is less than 0.1% by weight, the effect of the above-mentioned addition is insufficient. If the amount is more than 3% by weight, the problem of sticking of the toner component to the photoreceptor tends to occur.

The use of the third inorganic fine particles so that the total amount of the third inorganic fine particles and the first inorganic fine particles is 1.0 to 3.0% by weight prevents the problem of white spots caused by toner aggregation. Preferred from a viewpoint.

As the binder resin used in the toner of the present invention, known resins can be used, for example, styrene resins, acrylic resins such as alkyl acrylates and alkyl methacrylates, styrene-acrylic copolymer resins, and polyester resins. Resins, epoxy resins, silicon resins, olefin resins, amide resins and the like can be mentioned, and these can be used alone or in combination.

In the present invention, the binder resin used for full-color toners such as cyan toner, magenta toner, yellow toner and black toner has a number average molecular weight (Mn) of 3,000 to 6,000, preferably 35.
00 to 5500, the ratio Mw / Mn of the weight average molecular weight (Mw) to the number average molecular weight (Mn) is 2 to 6, preferably 2.5
~ 5.5, glass transition point 50 ~ 70 ° C, preferably 5
It is preferable to use a polyester resin or an epoxy resin having a temperature of 5 to 65 ° C and a softening point of 90 to 110 ° C, preferably 90 to 105 ° C.

The number average molecular weight of the binder resin is 3000
If it is smaller than that, the image portion is peeled off when a full-color solid image is bent, causing image defects (bending fixability is deteriorated). If it is larger than 6000, the heat melting property at the time of fixing is reduced and the fixing strength is reduced. I do. If Mw / Mn is less than 2, high-temperature offset is likely to occur, and if it is greater than 6, sharp melt characteristics at the time of fixing deteriorate, and the light transmittance of the toner and the color mixing at the time of full-color image formation decrease. I will. On the other hand, if the glass transition point is lower than 50 ° C., the heat resistance of the toner becomes insufficient, and the toner tends to aggregate during storage. If the glass transition point is higher than 75 ° C., the fixability decreases and the color mixture during full-color image formation. Is reduced. If the softening point is lower than 90 ° C., high-temperature offset is likely to occur, and 1
If the temperature is higher than 10 ° C., the fixing strength, the light transmittance, the color mixing, and the gloss of a full-color image are reduced. As the polyester resin, those containing etherified diphenols as an alcohol component and aromatic dicarboxylic acids as an acid component can be used.

As the above-mentioned etherified diphenols,
For example, polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene (2) -2,2-bis (4-hydroxyphenyl) propane and the like can be mentioned.

In addition to the above etherified diphenols, diols such as ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentyl glycol, etc. Kind,
Sorbitol, 1,2,3,6-hexanetetrol,
1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 1,2,2
4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2
-Methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxymethylbenzene and the like may be used.

As the aromatic dicarboxylic acids, aromatic dicarboxylic acids such as terephthalic acid and isophthalic acid, acid anhydrides thereof and lower alkyl esters thereof can be used.

Further, aliphatic dicarboxylic acids such as fumaric acid, maleic acid, succinic acid, alkyl or alkenyl succinic acids having 4 to 18 carbon atoms, and aliphatic dicarboxylic acids such as acid anhydrides or lower alkyl esters thereof are used. You may.

Also, 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid,
2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanenetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane, Polyvalent carboxylic acids such as 4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, anhydrides thereof and lower alkyl esters are used as acid values of polyester resins. Adjustment of,
For the purpose of improving the resin strength, a small amount may be used as long as the translucency is not impaired. When used for a black toner, it is not necessary to particularly consider the translucency.

As the colorant used in the toner of the present invention,
Known ones can be used and are not particularly limited.

It is preferable that the colorant used in the color toner has improved dispersibility of the colorant by a master batch process or a flushing process. The content of the colorant is preferably 2 to 15 parts by weight based on 100 parts by weight of the binder resin.

The toner of the present invention may contain desired additives such as a charge control agent, a magnetic powder, and a wax, in addition to the colorant.

Known charge control agents can be used, and are not particularly limited. The charge control agent used for the color toner is the color tone of the color toner,
A colorless, white or light-colored charge control agent which does not adversely affect light transmittance can be used. It is preferable to use a charge control agent such as a system compound. The salicylic acid metal complex is described in, for example,
JP-A-127726, JP-A-62-145255 and the like; calixarene-based compounds described in, for example, JP-A-2-201378 and the like; -221
No. 967 and the like, and fluorine-containing quaternary ammonium salt-based compounds are described, for example, in JP-A-3-1162.
Publications described in Japanese Patent Application Laid-Open No. H10-260, etc. can be used.

When such a charge control agent is added,
It is preferable to use 0.1 to 10 parts by weight, preferably 0.5 to 5.0 parts by weight, based on 100 parts by weight of the binder resin.

The toner of the present invention can be used as a two-component developer toner mixed with a carrier and a one-component developer toner without a carrier.

As the carrier used in combination with the toner of the present invention, those conventionally known as carriers for two-component developers can be used. For example, carriers made of magnetic particles such as iron and ferrite can be used. A resin-coated carrier obtained by coating such magnetic particles with a resin,
Alternatively, a binder-type carrier formed by dispersing a magnetic fine powder in a binder resin or the like can be used. Among these carriers, a silicone resin as a coating resin,
Use of a resin-coated carrier using a copolymer resin (graft resin) of an organopolysiloxane and a vinyl monomer or a polyester-based resin, or a binder-type carrier using a polyester-based resin as a binder resin is a toner spent. Carriers coated with a resin obtained by reacting an isocyanate with a copolymer resin of an organopolysiloxane and a vinyl monomer are preferred from the viewpoint of durability, environmental stability and spent resistance. Is preferred. As the vinyl monomer, it is necessary to use a monomer having a substituent such as a hydroxyl group reactive with isocyanate. Further, it is preferable to use a carrier having a volume average particle diameter of 20 to 100 μm, preferably 30 to 80 μm, from the viewpoint of securing high image quality and preventing carrier fogging.

[0051]

EXAMPLES Hereinafter, the present invention will be described specifically with reference to examples, but the present invention is not limited thereto.

(Production of Polyester Resin) A 2-liter four-necked flask was equipped with a reflux condenser, a water separator, a nitrogen gas inlet tube, a thermometer, and a stirrer. , 2) -2,2
-Bis (4-hydroxyphenyl) propane (PO),
Polyoxyethylene (2,0) -2,2-bis (4-hydroxyphenyl) propane (EO), fumaric acid (F
A) and terephthalic acid (TPA) in a molar ratio of 5:
The reaction mixture was charged so that the ratio became 5: 5: 4, and the reaction was carried out by heating and stirring while introducing nitrogen into the flask. The progress of the reaction was monitored while measuring the acid value. When the acid value reached a predetermined value, the reaction was terminated, and the number average molecular weight Mn was 4,800, and the ratio Mw / Mn of the weight average molecular weight Mw to the number average molecular weight Mn was calculated. 4.
0, a polyester resin having a glass transition point of 58 ° C and a softening point of 100 ° C was obtained.

The number average molecular weight and the weight average molecular weight were measured by gel permeation chromatography (807-I).
(T type: manufactured by JASCO Corporation), the column was kept at 40 ° C., tetrahydrofuran was flowed at 1 kg / cm ³ as a carrier solvent, and 30 mg of a sample to be measured was dissolved in 20 ml of tetrahydrofuran. 5m
g was introduced together with the above-mentioned carrier solvent, and determined in terms of polystyrene.

The glass transition point was measured using a differential scanning calorimeter (DSC-200: manufactured by Seiko Instruments Inc.).
About 0 mg, the measurement was performed at a heating rate of 10 ° C./min using alumina as a reference, and the shoulder value of the main absorption peak was defined as the glass transition point.

For the softening point, use a flow tester (CF
T-500: manufactured by Shimadzu Corporation) for 1.0 g of a sample, using a die having a pore diameter of 1.0 mm and a pore length of 1.0 mm, a temperature rising rate of 3.0 ° C./min, and a preheating time of 18
The measurement was performed under the conditions of 0 seconds, a load of 30 kg, and a measurement temperature range of 60 to 140 ° C., and the temperature at which the sample flowed out by １ ／ was defined as the softening point.

(Production of Toner Particle A) The above polyester resin and magenta pigment (CI Pigment Red 18)
4) was charged and kneaded in a pressure kneader so that the weight ratio of resin: pigment was 7: 3. The obtained kneaded material was cooled and pulverized by a feather mill to obtain a pigment master batch.

93 parts by weight of the polyester resin, 10 parts by weight of the pigment masterbatch, and 2 parts by weight of a charge control agent (zinc salicylate complex: E-84: manufactured by Orient Chemical Industries) were mixed with a Henschel mixer. The mixture was kneaded with a screw extruder. The resulting kneaded product was cooled, coarsely pulverized by a feather mill, finely pulverized by a jet mill, and classified to obtain toner particles A having a volume average particle size of 8.5 μm. The blow-off charge of the toner particles with respect to the iron powder was -53 [mu] C / g. Further, the amount of blow-off charge was measured at -20 μC / g when the iron powder was replaced with a carrier obtained in a carrier production example described later.

The measurement of the amount of charge of the blow-off is based on the blow-off method and is based on a standard iron powder carrier (Z150 / 250).
25g (made by Powder Tech) and 50mg of sample 25c
After placing in a polybin of c and mixing with a turbuler mixer for 1 minute, 0.1 g of the sample was placed in a measuring container having a 400 mesh stainless screen, and a nitrogen gas flow rate of 1.0 kgf / cm ² and an inflow time of 60 seconds were used. And blow-off charge meter (TB-200: manufactured by Toshiba Chemical Corporation)
Was measured.

(Production of Toner Particles B) 100 parts by weight of the above polyester resin, 3 parts by weight of carbon black (Mogal L: manufactured by Cabot), and a charge control agent (zinc salicylate complex: E-84: manufactured by Orient Chemical Industries) 2 After mixing parts by weight with a Henschel mixer, the mixture was kneaded with a twin-screw extruder. After cooling the obtained kneaded material, it is roughly pulverized by a feather mill, finely pulverized by a jet mill, and classified to obtain toner particles B having a volume average particle diameter of 8.5 μm.
I got The blow-off charge of the toner particles with respect to the iron powder was -48 [mu] C / g. Further, when the amount of blow-off charge was measured by replacing the iron powder with the carrier obtained in a carrier production example described later, it was -18 μC / g.

(Adjustment of Toner) The toner particles and the inorganic fine particles 1 were mixed with the toner particles obtained above using the external additives shown in Table 1 in the amounts shown in Table 2 using a Henschel mixer. After that, other inorganic fine particles were charged and mixed, and then the toner of each experimental example was obtained through a 200-mesh circular vibrating screen. The apparent apparent specific gravity, angle of repose and k1 of each of the obtained toners are shown in Table 2, and the relationship between the apparent apparent specific gravity and the angle of repose is shown in FIG. The loose apparent specific gravity and angle of repose were measured with a powder tester PT-E type (manufactured by Hosokawa Micron Corporation).

[0061]

[Table 1]

[0062]

[Table 2]

(Example of Carrier Production) Capacity 500 with Stirrer, Condenser, Thermometer, Nitrogen Introducing Tube, Dropping Device
100 parts by weight of methyl ethyl ketone was charged into a ml flask. Separately, methyl methacrylate at 80 ° C under nitrogen atmosphere
36.7 parts by weight, 5.1 parts by weight of 2-hydroxyethyl methacrylate, 58.2 parts by weight of 3-methacryloxypropyltris (trimethylsiloxy) silane and 1,1'-azobis (cyclohexane- A solution obtained by dissolving 1 part by weight of 1-carbonitrile in 100 parts by weight of methyl ethyl ketone was dropped into a reaction vessel over 2 hours and aged for 5 hours.

To the obtained resin, isophorone diisocyanate / trimethylolpropane adduct (IPDI / TMP system: NCO% = 6.1%) was added as a crosslinking agent to O.
After adjusting the H / NCO molar ratio to be 1/1, it was diluted with methyl ethyl ketone to prepare a coat resin solution having a solid ratio of 3% by weight.

Fired ferrite powder F-300 as core material
(Volume average particle size: 50 μm, manufactured by Powder-Tech Co.), and the above coating resin solution is applied and dried by a spira coater (manufactured by Okada Seiko Co., Ltd.) so that the amount of coating resin with respect to the core material is 1.5% by weight. did. The obtained carrier was calcined at 160 ° C. for 1 hour in a hot-air circulation oven. After cooling, the ferrite powder bulk was
The mixture was crushed using a sieve shaker equipped with a 5 μm screen mesh to obtain a resin-coated carrier.

(Aggregation noise (white spots)) Each toner was mixed with the carrier obtained in the above-mentioned production example at a toner mixing ratio of 7% by weight.
To prepare a developer. This developer was used under a N / N environment (25 ° C., 50%) using a digital full-color copying machine CF900 (manufactured by Minolta).
/ W15% images were printed on 5000 sheets. After printing, three full-size solid images (ID = 1.2) are printed on A3 paper.
Evaluation was performed according to the following criteria, and the average value of the three sheets was used as the evaluation result. The evaluation criterion is x when the image unevenness (white spot) having an ID of 1/2 or less of the solid image ID of 2 mm ² or more in the solid image occurs, and the white spot does not occur. Are observed in the image where nuclei of aggregates of about 0.3 μm are observed and the surrounding image density is slightly reduced at three or more places in the image. Those that did not occur at all were marked with ◎. Table 3 shows the results.

(Environmental stability) The developer prepared in the same manner as described above was used under CF / L900 under L / L environment (1
(0 ° C., 15%), an image of B / W 15% was formed. The image density (ID) of the obtained image is determined by a Macbeth reflection densitometer R
Measured by D-900, the image density is 1.2 or more,
1.0 or more and less than 1.2 were evaluated as Δ, and less than 1.0 was evaluated as x.

Using a CF900, 5,000 images of B / W 15% were imaged in an H / H environment (30 ° C., 85%). The white part of the obtained image was evaluated by visual observation, and the result was evaluated as follows: ○: no fogging occurred in the image; Δ: slight fogging but no practical problem; Is indicated by x. Table 3 shows the results.

(Fixing of Toner Component on Photoconductor (BS))
For the developer adjusted in the same manner as above, CF900
5,000 images of B / W 15% under N / N environment using
Printed. Evaluation was performed by visual observation on the photoreceptor at the beginning and after printing and evaluation by electron microscope observation, and evaluation by visual observation of a solid image at the beginning and after printing was performed. The external additives were not fixed on the photoreceptor by electron microscope observation. ◎ The external additives were fixed on the photoreceptor by electron microscope observation, but the external additive was fixed by visual observation. O: No image noise was observed and no image noise was generated. O: External additives and toner components were fixed on the photoreceptor by visual observation. When the external additive and toner component were fixed on the top, and this was recognized as noise on the image, it was evaluated as x. Table 3 shows the results.

(Evaluation of Smoke After Printing Durability) With the developer prepared in the same manner as described above, 5,000 sheets of B / W 15% images were subjected to printing durability in an N / N environment using CF900. When the photoreceptor was removed and the developing device was driven after printing, the toner did not rise from the developing sleeve when the developing device was driven.
The toner rises slightly from the sleeve, but if there is no fog on the image and no in-machine contamination,
The toner was evaluated as “△” when the toner was raised from the sleeve and the inside of the machine was stained but no image fogging was generated, and when the toner was soared from the sleeve, the image was fogged and the machine was stained as ×. Table 3 shows the results.

(Photoreceptor Scratches) With respect to the developer prepared in the same manner as above, B / B
5000 sheets of 15% W images were printed. After the printing, the photoreceptor surface was visually evaluated and the image was evaluated. If the photoreceptor surface had no scratches and no image streaks were observed, the photoreceptor surface appeared to be slightly cloudy, but image streaks occurred. If the photoreceptor had scratches on the photoreceptor surface and the image streaks occurred, the result was within the practical range. It evaluated as x. Table 3 shows the results.

(Heat resistance storage stability) When 5 g of the toner was put in a glass bottle and stored at 50 ° C. for 24 hours, a toner having a toner agglomeration was evaluated as x. Those that could not be seen were marked with ○. Table 3 shows the results.

[0073]

[Table 3]

[0074]

According to the present invention, it is possible to provide a toner and a developer for developing an electrostatic latent image which are excellent in fluidity and do not cause the problem of toner dust even when printing is performed. Further, according to the present invention, it is possible to provide an electrostatic latent image developing toner and a developer free from the problem of adhesion of the toner component to the photoreceptor and the problem of white spots in a solid image even when repeatedly used. Further, according to the present invention, it is possible to provide an electrostatic latent image developing toner and a developer having a stable toner charge amount even in a high temperature and high humidity environment and a low temperature and low humidity environment. Also,
According to the present invention, it is possible to provide an electrostatic latent image developing toner and a developer suitable for full-color image formation.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a relationship between a loose apparent specific gravity and a repose angle of toners of an example and a comparative example.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hiroyuki Fukuda 2-3-113 Azuchicho, Chuo-ku, Osaka-shi Osaka International Building Minolta Co., Ltd.

Claims (9)

[Claims] 1. An electrostatic latent image developing toner containing toner particles containing a colorant and a binder resin, wherein the toner has an angle of repose X (°) and a volume average particle diameter D.
₅₀ (μm) and the loose apparent specific gravity AD (g / cc) are as follows (1) to (6): AD = (− 0.005X + k ₁ ) × (D ₅₀ /8.5) ^1/2 (1) k ₁ = 0.57 to 0.64 (2) AD = k ₂ × (D ₅₀ ) ^1/2 (3) k ₂ = 0.135 to 0.158 (4) X = 28 ° to 38 ° (5) D ₅₀ = 3 to 10 μm (6) An electrostatic latent image developing toner, characterized by satisfying the following condition: 2. The toner according to claim 1, wherein the toner contains toner particles, first inorganic fine particles having a number average particle diameter of 10 to 30 nm, and second inorganic fine particles having a number average particle diameter of 100 to 1000 nm. The toner for developing an electrostatic latent image according to the above. 3. The toner according to claim 1, wherein the first inorganic fine particles have the same polarity as the toner particles in terms of triboelectric charging characteristics based on the toner particles, and have a larger chargeability than the toner particles. 3. The toner for developing an electrostatic latent image according to claim 2, wherein the toner has an opposite polarity to that of the toner. 4. The toner according to claim 1, wherein the toner has a number average particle diameter of 30 to 9.
The toner for developing an electrostatic latent image according to claim 2, further comprising 0 nm third inorganic fine particles. 5. The toner according to claim 1, wherein the toner is a toner used in a full-color image forming apparatus that reproduces a multicolor image using magenta, cyan, yellow, and black toners. An electrostatic latent image developing toner. 6. An electrostatic latent image developer comprising a toner comprising toner particles containing a colorant and a binder resin, an external additive attached to the surface of the toner particles, and a magnetic carrier. Angle of repose X (°), volume average particle diameter D ₅₀ (μm) and loose apparent specific gravity AD (g / cc)
Are as follows: (1) to (6): AD = (− 0.005X + k ₁ ) × (D ₅₀ /8.5) ^1/2 (1) k ₁ = 0.57 to 0.64 (2) AD = k ₂ × (D ₅₀ ) ^1/2 (3) k ₂ = 0.135 to 0.158 (4) X = 28 ° to 38 ° (5) D ₅₀ = 3 to 10 μm (6) An electrostatic latent image developer. 7. The external additive having a number average particle size of 10 to 3
0 nm first inorganic fine particles and a number average particle size of 100 to 10
7. The electrostatic latent image developer according to claim 6, comprising second inorganic fine particles having a thickness of 00 nm. 8. The toner according to claim 1, wherein the magnetic carrier has a charge of a polarity opposite to that of the toner particles in a triboelectric charge characteristic based on the toner particles, and the first inorganic fine particles have the same polarity as the toner particles and have a higher polarity than the toner particles. It has great chargeability,
8. The electrostatic latent image developer according to claim 7, wherein the second inorganic fine particles have a chargeability opposite in polarity to the toner particles, and the chargeability is larger than that of the magnetic carrier. 9. The toner according to claim 1, wherein the toner has a number average particle size of 30 to 9.
The electrostatic latent image developer according to claim 7, further comprising 0 nm third inorganic fine particles.