JP2000267336A - Toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the toner superior in fluidity and environmental stability and also coagulation resistance and durability. SOLUTION: This toner contains the toner particles and fine outer additive particles treated with a silane coupling agent and this treated agent has a fraction extractable in a chloroform solvent of 2.0-20.0 weight % of the treated agent, and a weight decrease of this extracted fraction is 0-5 weight % after being left for 5 days at 25 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 for developing an electrostatic image in electrophotography, electrostatic recording, and the like.

[0002]

2. Description of the Related Art In electrophotography, an electrostatic image formed on a photoreceptor is usually developed with a toner containing a pigment or the like, and the obtained toner image is transferred onto a transfer paper and fixed by a hot roll or the like. ,
On the other hand, the photoconductor is cleaned again to form an electrostatic image.

[0003] A dry developer used in such an electrophotographic method includes a one-component developer using a toner itself in which a colorant is dispersed in a binder resin, and a two-component developer in which a carrier is mixed with the toner. When a copying operation is performed using these developers, in order to have process compatibility, the developers are required to have fluidity, anti-caking properties, fixing properties, charging properties, and cleaning properties. It is necessary to have excellent properties. In addition, in order to improve the fluidity and the blocking resistance, an inorganic fine powder is often added to the toner.

[0004] However, these fine powders have a great influence on the chargeability. For example, in the case of a silica-based fine powder that is generally used, there is a problem that the negative polarity is strong and a large difference occurs in chargeability between high-temperature high-humidity and low-temperature low-humidity environments. As a result, it may cause background fog and poor density reproduction.

[0005] Further, the dispersibility greatly affects the toner characteristics, and when the dispersibility is non-uniform, the desired characteristics cannot be obtained in the fluidity and the anti-blocking property, or the cleaning becomes insufficient, and the In some cases, toner sticking or the like occurs on the upper portion, which may cause white image defects.

For the purpose of improving these points, various proposals have been made to use inorganic fine powder that has been surface-treated. For example, Japanese Patent Application Laid-Open No.
JP-A-135854 discloses the use of silica treated with a charge control substance that positively controls the chargeability of toner.
In JP-A-123252, inorganic fine particles treated with a polysiloxane containing an ammonium salt as a functional group may be used. In JP-A-4-125568, dialkylaminoacrylate or dialkylaminomethacrylate may be used as a quaternary ammonium salt. Examples are described in each of which a toner obtained by performing a surface treatment of silica fine particles using a resin contained in the form is used. Regarding the negatively chargeable toner, Japanese Patent Application Laid-Open No. 7-31475 discloses that an external additive comprising negatively chargeable hydrophobic silica fine particles surface-treated with silicone oil is added to the surface of the magnetic toner base. Japanese Patent Application Laid-Open No. 10-10773 discloses a negatively charged toner obtained by mixing and adding at least three types of external additives.
Japanese Patent Application Laid-Open No. Hei 10-171155 proposes a toner containing inorganic fine particles that are positively charged and inorganic fine particles that are negatively charged when an external additive frictionally charges iron powder.

[0007]

However, the above-mentioned conventional proposals have advantages and disadvantages and do not always provide satisfactory results. For example, in the case of JP-A-55-135854, since the charge control substance to be treated is a dye, there is a problem that the external additive fine particles are colored and it is difficult to apply the additive to a color toner. Was. Furthermore, in the case of JP-A-10-171155, there is a problem that the allowable range for achieving both a sufficient image density and background fog is small because the charge amount distribution is wide. Also for other things,
It did not satisfy all the required properties.

Therefore, the present invention has been made in view of the above-mentioned situation in the prior art.

That is, an object of the present invention is to provide a toner which is excellent in both fluidity and chargeability and has excellent environmental stability from low temperature and low humidity to high temperature and high humidity. Another object of the present invention is to provide a toner which can provide a sufficient image density, has little background fogging, and does not easily generate white image defects. Furthermore, since the external additive is uniformly dispersed on the toner surface, it has excellent coagulation resistance and durability, transferability from the drum, cleaning performance, and reproduction of highlights (light image density) of the image. An object of the present invention is to provide a toner having excellent properties.

[0010]

According to the present invention, there is provided a toner having toner particles and external additive fine particles, wherein the external additive fine particles are treated with a silane coupling agent. The chloroform solvent extractables are 2.0 to 2 parts by weight based on the weight of the treated external additive fine particles.
0.05% by weight, and the amount of weight loss after leaving the chloroform solvent extract at a temperature of 25 ° C. for 5 days is 0 to 5% by weight.

That is, the toner of the present invention is obtained by adding fine particles treated with a silane coupling agent under optimum conditions to toner particles, whereby the charging characteristics of the external additive fine particles with respect to the carrier and the charging characteristics of the toner particles are improved. In addition, fine particles of the external additive are uniformly dispersed on the surface of the toner particles, and the particles are hardly released even when subjected to stress, so that the characteristics can be maintained for a long period of time.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, the present invention will be described in detail.

In the present invention, the fine particles of the external additive added to the toner particles preferably have an average particle diameter of 0.002 to 0.002.
0.1 μm, more preferably 0.005 to 0.05 μm
Those in the range are good.

If the average particle size is larger than 0.1 μm, it is difficult to impart fluidity, the charge amount of the toner tends to be uneven, and as a result, scattering of the toner tends to occur.
On the other hand, when the average particle size is smaller than 0.002 μm, the particles are likely to aggregate, and the fluidity tends to be low. The particle size of the external additive fine particles was measured by a transmission electron microscope.

The inventors of the present invention have conducted intensive studies on the problems of the conventional external additives, and found that the extracted amount of the treated external additive fine particles in the chloroform solvent was 2.% based on the weight of the treated external additive fine particles. 0 to 20.0% by weight, and the amount of weight loss after leaving the chloroform solvent extract at 25 ° C. for 5 days is 0%.
It has been found that it is important to control to be ５5% by weight. That is, “extracted external solvent particles in chloroform solvent” indicates the amount of the hydrophobized treatment agent, and “extracted chloroform solvent after extraction at 25 ° C. for 5 days” indicates the treated state. I found what it was. In the hydrophobization treatment of the external additive, the amount of the external additive actually adhered and the state after the treatment are important. If the external additive is localized and has a variation, it is released from the toner or uniformly dispersed on the toner surface. Instead, the rise of the charge is deteriorated, and the charge imparting member such as the carrier or the sleeve is contaminated.

When the amount of the external additive fine particles extracted with the chloroform solvent is less than 2.0% by weight, the hydrophobic treatment amount is too small and the durability under high humidity is poor. If the amount exceeds 20.0% by weight, the processing agent is excessively present, and contaminates a charge providing member such as a carrier and a sleeve under low humidity, and may cause toner scattering. On the other hand, if the weight loss after leaving for 5 days at a temperature of 25 ° C. of chloroform solvent extraction exceeds 5% by weight, it is considered that low molecular weight components such as monomers and dimers have volatilized, and they are contained in the treating agent. It is thought that it remains. In particular, the low molecular weight component is not preferable because it easily causes fluctuations in quality and changes with time, and causes problems in non-uniformity (roughness) in a highlight portion and fluidity of the toner in a high temperature environment.

The silane coupling agent on the external additive fine particles is represented by the following general formula (I):

[0018]

Embedded image It is preferable to include those having the structure represented by The fact that the substance in this state is found on the external additive fine particles serves as an index of whether or not the surface hydrophobization reaction is stably performed even if the degree of hydrophobicity is the same. That is, it has been found that stability against environmental differences is more favorable for those in which this compound is found. This compound can be confirmed by NMR spectrum after solvent extraction.

The chloroform solvent extractables were obtained by GPC.
According to the measured molecular weight distribution, the weight average molecular weight is 60.
Desirably, it is 0 to 1800. When the weight-average molecular weight is less than 600, fog in a low humidity environment tends to slightly increase. When it exceeds 1800, the external additive fine particles tend to be slightly non-uniformly adhered to the toner surface, and the roughness of the highlight portion tends to be deteriorated.

The treating agent used in the present invention can be produced by a known method.

As a method of hydrophobizing treatment by a wet method, first, a predetermined amount of a hydrophobizing agent or a diluent thereof or a mixture thereof is added while sufficiently mixing and stirring a predetermined amount of external additive fine particles in an aqueous system. After thoroughly mixing and stirring, the mixture is dried and crushed.

In the present invention, the treating agent is used in a treating amount of 0.1 to 300% by weight, preferably 0.5 to 150% by weight based on the fine particles. As a processing method,
A method of dissolving the above polymer in an appropriate solvent, adding it to external additive fine particles, coating the surface, and then drying the solvent is common.Specifically, a kneader coater, a spray dryer, a thermal processor, It is preferable to use a device such as a floor. Further, a method is preferred in which the coupling agent is hydrolyzed and treated while mechanically dispersing the fine particles in the solution so as to have a primary particle diameter. In the present invention, it is particularly preferable to treat the surface using two kinds of solvents having different solubilities of the coupling agent. The stepwise addition of the solvent in which the hydrophobizing agent is dispersed with respect to the external additive fine particles is an example of a means capable of imparting the specific physical properties of the present invention, but is not necessarily limited to this means. Not something.

Further, it is also possible to carry out a hydrophobizing treatment using two or more kinds of hydrophobizing agents, for example, i-C ₄ H _9-
Si- (OCH _{3) 3} and _{i-C 12 H 25 -Si- (} OC
When two types of coupling agents are mixed to form a hydrophobizing agent as in H ₃ ) ₃ and subjected to a hydrophobizing treatment,
The hydrophobizing agent having a small number of carbon atoms reacts with the hydroxyl group on the surface of the external additive fine particles. Next, by reacting the unreacted hydroxyl group on the particle surface with the hydrophobic agent having a large number of carbon atoms, it is possible to control how the hydrophobic agent adheres to the surface.

Further, if necessary, it may be pulverized after drying and classified. In using these methods, conditions, such as conditions, are not particularly limited.

In the present invention, examples of the hydrophobizing agent that can be used include the following. Vinyltrimethoxysilane, vinyltriethoxysilane, γ-
Examples thereof include methacryloxypropyltrimethoxysilane, methyltrimethoxysilane, methyltriethoxysilane, isobutyltrimethoxysilane, and alkylmethoxysilanes such as dimethyldimethoxysilane and octyltrimethoxysilane. It is also possible to use alkylchlorosilanes such as methyltrichlorosilane, octyltrichlorosilane and dimethyldichlorosilane, hexamethyldisilazane, silicone oil and the like in combination.

[0026] In the present invention, particularly suitable are the general formula _{C n H 2n + 1 -Si- (} OC m H 2m + 1) 3 n = 4~12, a coupling agent represented by m = 1 to 3. Here, when n in the general formula is smaller than 4, the treatment becomes easy, but the degree of hydrophobicity tends to be insufficient. On the other hand, if n is larger than 12, the hydrophobicity will be sufficient, but the coalescence of the external additive fine particles will increase, and the ability to impart fluidity will decrease. On the other hand, if m is larger than 3, the reactivity is lowered and the hydrophobic treatment is not sufficiently performed.

The degree of hydrophobicity of the external additive fine particles is 30 to 9
If the degree of hydrophobicity of the external additive fine particles is less than 30%, the amount of charge will be greatly reduced due to long-term storage under high humidity, and a mechanism for accelerating the charge will be required, thus complicating the apparatus. Inevitable. If the degree of hydrophobicity exceeds 90%, it is difficult to control the charging of the external additive fine particles themselves, and as a result, the toner is undesirably charged up under low humidity.

The measurement of the degree of hydrophobicity is based on the following method. The same applies to the embodiments described later.

(Measurement of degree of hydrophobicity)
This is an experimental test for confirming the degree of hydrophobicity of external additive fine particles having a hydrophobicized surface.

0.2 g of the external additive fine particles are added to 50 ml of water in a 250 ml Erlenmeyer flask. Methanol is titrated from the buret until the entire amount of the external additive fine particles is wetted. At this time, the solution in the flask is constantly stirred with a magnetic stirrer. The end point is observed when the entire amount of the external additive fine particles is suspended in the liquid, and the degree of hydrophobicity is expressed as a percentage of methanol in the liquid mixture of methanol and water when the end point is reached.

The material of the external additive fine particles is not particularly limited, but it is preferable to use alumina or titanium oxide whose charging characteristics are close to neutral.

In the present invention, as the toner particles, known particles composed mainly of a binder resin and a colorant are used.

As the binder resin used, styrene,
Styrenes such as chlorostyrene; monoolefins such as ethylene, propylene, butylene and isoprene; vinyl esters such as vinyl acetate, vinyl propionate, vinyl benzoate and vinyl butyrate; methyl acrylate, ethyl acrylate, butyl acrylate and acrylic Α-methylene aliphatic monocarboxylic esters such as dodecyl acid, octyl acrylate, phenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate; vinyl methyl ether, vinyl ethyl ether, vinyl butyl ether, etc. Vinyl ethers;
Examples thereof include homopolymers or copolymers of vinyl ketone such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone. Particularly typical binder resins include polystyrene, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer, and styrene-maleic anhydride copolymer. Examples include polymers, polyethylene, and polypropylene. In addition, polyester, polyurethane, epoxy resin, silicone resin, polyamide, modified rosin,
Examples include paraffin wax.

Examples of the colorant for the toner include carbon black, nigrosine dye, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, malachite green oxalate, Lamp black, rose bengal,
C. I. Pigment Red 48: 1, C.I. I. Pigment Red 122, C.I. I. Pigment Red 5
7: 1, C.I. I. Pigment Yellow 97, C.I. I.
Pigment Yellow 12, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 15: 3 and the like can be exemplified as typical examples.

The toner particles in the present invention may contain known additives such as a charge control agent, if desired.

Further, the toner particles in the present invention may be a magnetic toner containing a magnetic material or a capsule toner.

The toner particles in the present invention generally have a particle size of 3 to
Those having an average particle size of 15 μm can be suitably used.

[0038] The toner of the present invention may optionally contain additives other than those described above.

For example, there are fine particles which function as a charge assisting agent, a conductivity-imparting agent, an anti-caking agent, a releasing agent at the time of hot roll fixing, a lubricant, an abrasive and the like. Specifically, a lubricant such as Teflon (registered trademark), zinc stearate, polyvinylidene fluoride, or cerium oxide, silicon carbide,
Abrasives such as strontium titanate, anti-caking agents, or conductivity-imparting agents such as carbon black, zinc oxide, antimony oxide, and tin oxide, and white and black fine particles of opposite polarity are used in small amounts as developability improvers. You can also.

In the present invention, the surface-treated fine particles are
The toner particles are added to the toner particles and mixed.
It can be performed by a mold blender, a Henschel mixer, or the like.

The addition amount of the external additive fine particles is preferably in the range of 0.05 to 20% by weight, more preferably in the range of 0.1 to 5% by weight, based on the total weight of the toner. Content is 0.
If less than 05% by weight, high fluidity of the toner,
On the other hand, when the content exceeds 20% by weight, sufficient fluidity of the toner is too high, so that it is difficult to obtain uniform charging.

As described above, the toner of the present invention to which the external additive fine particles are added can be used as a one-component developer or a two-component developer.

When used as a two-component developer, the external additive fine particles are not added to the toner particles in advance,
It may be added at the time of mixing the toner and the carrier, and may be externally added simultaneously with the mixing of the toner and the carrier.

When the carrier is used as a two-component developer, the carrier may be iron powder, glass beads, ferrite powder, magnetite powder, nickel powder, magnetic fine powder dispersed in resin, and granulated. The surface of which is coated with a resin is used.

[0045]

The present invention will be described more specifically with reference to the following examples. However, the present invention is not limited by this embodiment. In the following description, all “parts” represent “parts by weight”.

Production of External Additive Fine Particles: [External Additive Fine Particles G-1] 2 liters of a 0.2 M ammonium alum solution was added to 3 liters of a 2 M ammonium bicarbonate solution while maintaining the temperature at 30 ° C. for 0 hour. The mixture was dropped at a rate of 0.8 liter and reacted sufficiently with stirring to produce aluminum ammonium carbonate hydroxide fine powder, which was filtered, dried and crushed.

Here, the pulverization was carried out by a speed mill and repeated until the aggregates disappeared, so that the number of fine powders having a primary particle diameter of 80 nm or more was 5% by number or less. The fine powder was heat-treated at about 900 ° C. for 24 hours to produce alumina fine powder. This alumina fine powder has a BET specific surface area of 260 m ² / g, an average particle diameter of 8 nm, and 99% by number of particles having a particle diameter of 1 to 60 nm, and it is confirmed by X-ray diffraction that the crystal type is γ-based. Was done.

Next, the alumina fine powder was sufficiently wet-pulverized in a mixed solvent of toluene and methanol with a ball mill using zirconia balls having a diameter of 2 mm, and the alumina fine powder was sufficiently dispersed in the solution. As an agent, i
_{-C 4 H 9 -Si- (OCH 3} ) 3 alumina fine powder 100
The liquid temperature was 44 ° C. so that the solid content was 30 parts per part.
, And the mixture was added dropwise while stirring to hydrolyze. Then, after filtering and drying, it was baked at 160 ° C. for 2 hours and crushed. Crushing was performed by a speed mill to obtain external additive fine particles G-1 (alumina fine particles).

Table 1 shows various physical properties of the external additive fine particles G-1 to G-11.

[External additive fine particles G-2] The average particle diameter is 10 n.
The alumina fine powder obtained by the method for producing fine alumina powder described in Production Example G-1 in which 97% by number of particles having a particle diameter of 1 to 60 nm are 97% by number is sufficiently wet-processed by a ball mill using a medium having a small particle diameter. after grinding, while thoroughly mixing and _{stirring, i-C 4 H 9 -Si-} (OCH 3) 3 and i-C ₁₂ H ₂₅
-Si- (OCH ₃ ) _{3 in a} ratio of 1: 1 was mixed with a hydrophobizing agent at a solid content of 40 parts by weight based on 100 parts by weight of alumina fine powder.
It was added so as to be parts by weight. At this time, first, 1/10 equivalent of the total amount of the hydrophobizing agent was added. After sufficiently mixing and stirring, the remaining 9/10 equivalents of the hydrophobizing agent were added while mixing and stirring. Further, after sufficiently mixing and stirring, the mixture was dried and crushed to obtain external additive fine particles G-2.

[External additive fine particles G-3] Titanium tetraisopropoxide was used as a raw material. Using a chemical pump, feed the raw material in small quantities, using nitrogen gas as a carrier gas, feed it into the glass wool of a paper riser heated to 200 ° C, evaporate it, heat decompose it at a temperature of 320 ° C in the reactor, and then quench The product was collected to obtain hydrophilic amorphous titanium oxide fine powder (1). This was calcined at 300 ° C. for 2 hours to obtain hydrophilic crystalline titanium oxide fine powder (2).

Next, hydrophobic treatment was performed in the same manner as in Production Example G-1 to obtain external additive fine particles G-3.

[External additive fine particles G-4] External additive fine particles G-
In 3 of Preparation, i-C ₄ H ₉ -Si as a hydrophobic agent
- (OCH _{3) 3} and the _{C 6 H 13 -Si- (OCH 3} ) 3 1: except using a mixture 1 in the same manner, to obtain an external additive fine particle G-4.

[External additive fine particles G-5] External additive fine particles G-
In Production Example 3, the addition amount of the hydrophobizing agent was 25 parts,
An external additive was prepared in the same manner as above except that the treatment temperature after filtration and drying was changed to heating at 130 ° C. for 2 hours, and the crushing treatment after the hydrophobization treatment was repeatedly performed until the titanium oxide aggregates disappeared. Fine particles G-5 were obtained.

[External additive fine particles G-6] External additive fine particles G-
In Production Example 1, hydrophobic silica (R972, manufactured by Nippon Aerosil Co., Ltd .; primary average particle size: 16) was used instead of alumina.
nm), but treated silica fine particles G-6 were obtained in the same manner.

[External additive fine particles G-7] External additive fine particles G-
In the same manner as in Production Example 1, except that only toluene was used as the solvent, external additive fine particles G-7 were obtained.

[External Additive Fine Particles G8 to 11] In the production example of the external additive fine particles G-3, except that the mixing condition of the hydrophobizing agent and the stirring speed were changed and that only toluene was used as the solvent, In the same manner as in the production example of the external additive fine particles G-3, external additive fine particles G8 to 11 were obtained.

Each of the external additive fine particles was subjected to solvent extraction using chloroform, and the NMR spectrum was examined. G-1, G-3, G-4, G-5 and G-6 were determined.
A peak attributable to the compound (polyisobutylmethoxysilane) having the structure represented by the general formula (I) was observed (see FIG. 1). No clear peaks appeared for the others (see FIG. 2).

Example 1 100 parts of polyester resin obtained by condensing propoxylated bisphenol and fumaric acid 5 parts of phthalocyanine pigment 4 parts of chromium complex of di-tert-butylsalicylic acid were sufficiently premixed with a Henschel mixer. After doing
The mixture was melt-kneaded at least twice with a three-roll mill, cooled, and coarsely ground to a particle size of about 1 to 2 mm using a hammer mill. Next, it was pulverized by a pulverizer using an air jet method. Further, the obtained finely pulverized material was classified by a multi-segment classifier, and the volume average particle size was 7.3 μm, and 4 μm or less was 1 μm.
0 volume%, 12.7 μm to 16 μm is 0.6 volume%, 1
Colorant-containing resin particles (non-magnetic toner particles) having a particle size of 6 μm or more were substantially 0 were obtained.

After externally adding 1.1 parts of external additive fine particles G-11 shown in Table 1 to 100 parts of the toner particles,
The mixture was sieved with a 00 mesh screen to obtain a cyan toner.

Styrene-based toner was added to 6 parts of the cyan toner.
A developer was prepared by mixing 94 parts of Cu-Zn-Fe-based ferrite particles whose surface was coated with a methyl methacrylate-ethyl hexyl acrylate copolymer.

A copier (Canon color laser copier CLC730) was modified so that the peripheral speed of the sleeve was 200 mm / sec, and was normal temperature and normal humidity (23 ° C., 60% RH), low temperature and low humidity (15 ° C., 10% RH), High temperature and high humidity (35 ° C, 9
(5% RH), high-quality images with sufficient image density were obtained in each environment.
Further, a continuous copying test was performed, and the solid portion density and the background fog were measured at the initial stage, after 50,000 copies, and every 2,000 copies in the middle. In addition, the quality of the image was also observed. Table 3 shows the results.

Here, the fog generated on the white image was measured by a "reflectometer" (manufactured by Tokyo Denshoku Co., Ltd.). Fog (%) was calculated from the relationship between the whiteness of the white background passing through the fixing device and the whiteness of the transfer paper before passing through the fixing device, and the image stain was evaluated.

Further, the image density is low temperature and low humidity (15 ° C., 1
(0% RH), the worst values of fog, toner scattering, and highlight roughness in the three environments during the endurance, including the initial and after 50,000 sheets, were described.

[Examples 2 to 6 and Comparative Examples 1 to 5] Table 2
The results shown in Table 3 were obtained by the combination using the fine particles of the external additive shown in FIG.

(Evaluation Method) The state of the external additive dispersion was observed by FE-SEM for the state of the external additive fine particles on the toner surface. A: Almost no agglomerates were observed and the particles were almost uniformly dispersed on the toner surface. ：: Some are slightly aggregated, but are almost uniformly dispersed on the toner surface. Δ: External additive fine particles are sparse on the toner surface. C: Many aggregates and uneven toner surface.

In the highlight portion roughness, the image density was measured at 10 points for the same image density of 0.5, and the magnitude of the difference was evaluated. 〇: The difference is 0.1 or less. Δ: Difference is 0.2 or less. X: The difference exceeds 0.2.

The cohesiveness under high temperature and high humidity is determined by replenishing the developing device of the above-mentioned copying machine under the same environment by leaving the toner in a cup under an environment of 35 ° C. and 95% RH for 10 days, using 6 g of the toner as a sample under the same environment. It was supplied from the mouth and the state of charging was examined. 〇: No problem occurs in the image and the developing device. Δ: Fog slightly increased, but OK level. X: Fog and toner scattering occur.

The environmental stability is low temperature and low humidity (15 ° C., 10%
RH) and high temperature and high humidity (35 ° C., 95% RH). A: Density difference less than 0.1. 〇: Density difference 0.1 or more and less than 0.2. Δ: density difference of 0.2 or more.

The toner scatters at low temperature and low humidity (15 ° C., 10%
RH) and high-temperature and high-humidity (35 ° C., 95% RH) environments were visually evaluated for toner scattering around the developing device after copying 50,000 sheets. ：: In any environment, toner scattering around the developing device is extremely small. Δ: Slight scattering occurred in any of the environments, but no effect on the transfer material and the like was observed. ×: toner scattering occurs in any of the environments, and stains on the transfer material are observed.

[0071]

[Table 1]

[0072]

[Table 2]

[0073]

[Table 3]

[0074]

The toner of the present invention has a good powder flow improving effect which the external additive fine particles have because the external additive fine particles surface-treated with a coupling agent are added to exhibit the above-mentioned properties. And the effect of improving the chargeability and environmental stability can be achieved at the same time. Further, since the chargeability and the environmental stability from low-temperature and low-humidity to high-temperature and high-humidity environments are sufficient, a sufficient image density can be obtained, and image flaws with little background fog and white spots are hardly generated. Also, since the external additive is uniformly dispersed on the toner surface, it has excellent aggregation resistance and durability,
It is excellent in transferability from the drum, cleaning performance, and reproducibility of a highlight portion (a portion having a low image density) of an image.

[Brief description of the drawings]

FIG. 1 shows external additive fine particles G-1, G-3 to G- in Examples.
6 shows a conceptual diagram of an NMR spectrum observed for No. 6.

FIG. 2 shows external additive fine particles G-2 and G-7 to G- in Examples.
11 shows a conceptual diagram of an NMR spectrum observed for No. 11.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Junko Inaba 3-30-2 Shimomaruko, Ota-ku, Tokyo Within Canon Inc. (72) Inventor Iku Iku 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inside (72) Inventor Takaaki Uetaki 3-30-2 Shimomaruko, Ota-ku, Tokyo Canon Inc. F-term (reference) 2H005 AA08 CA12 CA26 CB07 DA05 DA07 EA06

Claims (5)

[Claims] 1. A toner having toner particles and external additive fine particles, wherein the external additive fine particles are treated with a silane coupling agent, and a chloroform solvent extract of the treated external additive fine particles is treated. 2.0 to 20.0% by weight based on the weight of the external additive fine particles, and the weight loss after leaving the chloroform solvent extract at a temperature of 25 ° C. for 5 days is 0 to 5% by weight. Toner. 2. The silane coupling agent has the following general formula: The toner according to claim 1, further comprising a condensate having a structural unit represented by the following formula: 3. The chloroform solvent extract has a weight average molecular weight of 600 in the molecular weight distribution measured by GPC.
3. The toner according to claim 1, wherein the number is from 1 to 1800. 4. 4. The toner according to claim 1, wherein the external additive fine particles are an inorganic oxide. 5. The toner according to claim 1, wherein the external additive fine particles are titanium oxide fine particles or alumina fine particles.