JP2003098728A - Toner and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toners capable of forming high-grade images which are less environmentally dependent, have excellent electrostatic charging characteristics, are free of toner fastening and eliminate the deterioration in image quality in spite of long-term use. SOLUTION: The toners having toner particles containing at least a binder resin, coloring agents and a release agent as components and a compound of hydrotalcites are characterized in that the half band width at the endothermic peak of the release agent is <=14 deg.C; the electrostatic charging means for electrostatically charging the surface of the photoreceptor in an image forming method to which this means is applied is an electrostatic charging roller having a conductive elastic layer; and the surface hardness of the electrostatic charging roller is 30 to 90 deg. in JIS (Japanese Industrial Standard)-A.

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 using an electrophotographic method, an electrostatic recording method, a toner jet recording method, and the like, and an image forming method. Specifically, a copying machine that forms a toner image on an electrostatic latent image carrier in advance and then transfers the image onto a transfer material to form an image,
The present invention relates to a toner used for a printer and a fax and an image forming method.

[0002]

2. Description of the Related Art Conventionally, a corona discharger has been known as a charging means in an electrophotographic apparatus or the like. However, the corona discharger has problems that a high voltage must be applied and that the amount of ozone generated is large.

Therefore, recently, it has been considered to use the contact charging means without using the corona discharger. Specifically, a voltage is applied to a conductive roller, which is a charging member, to bring the roller into contact with a photosensitive member, which is a member to be charged, to charge the surface of the photosensitive member to a predetermined potential. If such a contact charging means is used, the voltage can be lowered and the ozone generation amount can be reduced as compared with the corona discharger.

However, when the above contact charging means is used, there is a problem that charging failure occurs if sufficient contact cannot be maintained with the member to be charged. Also. At the contact part, if residual developer is present on the surface of the photoconductor, the charging member has a predetermined contact pressure, so the residual developer adheres to the charging member and the surface of the photoconductor, affecting the image. Have the problem of

Further, in the contact charging device, a DC voltage or a voltage in which an AC voltage is superimposed on a DC voltage is applied to the charging member to be used. At this time, the residual developer is left around the contact portion between the charging member and the photosensitive drum. Abnormal charging and flight movements are repeated, and as a result, it is easy to electrostatically attract or embed residual developer on the charging member or the surface of the photoconductor drum. It is very different from using the means. Therefore, in the image forming method using the contact charging device, a toner which is more durable and durable than the conventional toner is required.

Generally, in a one-component developer, a technique of adding metal oxide fine particles such as colloidal silica to the toner has been already known in order to impart fluidity to the toner and further uniformize the chargeability of the toner. However, desorption components of metal oxide fine particles due to continuous use and agglomerates formed with deterioration rub strongly against the surface of the photoconductor during image formation, so the photoconductor surface may be scraped or scratched. In many cases, there was a problem such as fusion of the residual developer caused by them. This problem remarkably appears when an abutting member such as the charging member that is in contact with the surface of the photoconductor with a predetermined abutting pressure is used.

On the other hand, a toner containing hydrotalcites is described in Japanese Patent No. 2584306 by M.
Although g-Al system has been proposed, NO from the photoconductor surface
_The purpose is to remove _X, etc., and the charging stability is insufficient. Also, Japanese Patent No. 2682331 and Japanese Patent Laid-Open No. 6-1
JP-A-38697 proposes a toner containing ternary or quaternary hydrotalcites obtained by adding one or two divalent metals (Zn or the like) to an Mg-Al system for the purpose of charging stability. Has been done. Although the hydrotalcite-containing toners described in these patents certainly have improved charging stability and transferability in harsh environments,
In the image forming method using the contact charging means, the charging roller is contaminated remarkably with the endurance, a defect occurs in the latent image formation of the latent image carrier, and a defective image copy is carried out. There was room for.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above points, and in an image forming method equipped with a contact charging device, the residual developer on the charging member and the surface of the member to be charged is An object of the present invention is to provide a toner and an image forming method in which the occurrence of image defects due to poor charging or uneven charging is prevented by preventing contamination such as sticking, or these phenomena are suppressed.

Further, an object of the present invention is to provide a toner having excellent environmental stability, excellent charge stability, and high durability capable of maintaining a high quality image even when a large number of copied images or printer images are output, and An object is to provide an image forming method using toner.

[0010]

The above object can be achieved by the present invention described below.

That is, the present invention is a charging roller having a charging step in which a charging member is brought into contact with the surface of a photoconductor to apply a voltage from the outside to carry out charging, and the charging member has a conductive elastic layer, The surface hardness of the charging roller is JIS-
A toner applied to an image forming method having an A of 30 degrees to 90 degrees, the toner having toner particles containing at least a binder resin, a colorant, and a release agent, and a hydrotalcite compound. The toner has a half width of 14 at the endothermic peak in differential thermal analysis (DSC) of the toner.
The present invention relates to a toner and an image forming method, wherein the hydrotalcite-based compound has a temperature of not higher than 0 ° C. and the general formula (1) shown below.

[0012]

[Chemical 5] (Wherein 0 <[X = (x1 + x2 + ... + xk)] ≦ 0.
5, Y = (y1 + y2 + ... + yj) = 1-X, and j
And k are integers of 2 or more, M1 ²⁺ , M2 2 ⁺ , ... And Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, A ^n-
Represents an n-valent anion, and m ≧ 0. )

[0013]

DETAILED DESCRIPTION OF THE INVENTION As a result of intensive investigations by the present inventors, a toner having at least a binder resin, a colorant, and a release agent as a constituent component and a toner having a hydrotalcite compound having a specific structure is used. The half-value width at the endothermic peak of the release agent is 14 ° C. or less, and the charging means for charging the surface of the photoreceptor is a charging roller having a conductive elastic layer, and the surface hardness of the charging roller is JIS. It has been found that the object of the present invention can be achieved to a high degree by using a toner and an image forming method characterized in that the toner has an -A value of 30 to 90 degrees.

The details will be described below.

First, matching between the charging roller used in the present invention and the hydrotalcite compound will be described.

When the toner of the present invention is a negatively chargeable toner, it is particularly effective in charge control having no environmental dependence.
Hydrotalcite compounds have the opposite polarity to the toner, and their presence on the toner surface increases the charge like a microcarrier in a high-temperature and high-humidity environment, and the charging rises quickly and uniformly. Therefore, it is effective in preventing fogging of the first sheet immediately after leaving. On the contrary, in a low-temperature and low-humidity environment, the toner is less likely to be charged up due to the positive charging effect of hydrotalcite, and high-quality images can be continuously output without density reduction and halftone image roughness.

Although it has an effect of supplementing the charge to the positively chargeable toner, the combination with the negatively chargeable toner produces a more remarkable effect and is excellent in stability.

However, as described above, the toner to which the hydrotalcite-type compound has been externally added is certainly less dependent on the environment and is very excellent in charging stability, but the charging means for charging the surface of the photoconductor has conductive elasticity. In the image forming method, which is a charging roller having a layer, a hydrotalcite compound is embedded in the charging roller due to the contact pressure of the charging roller, and as a result, a deterioration external additive or an aggregating component of the deterioration toner is accumulated. As a result, image defects are likely to occur.

Then, as a result of intensive investigations by the present inventors, the surface hardness of the charging roller is 30 to 90 degrees according to JIS-A.
It was found that the toner externally added with the hydrotalcite-based compound does not contaminate the charging roller and has excellent durability only when the temperature is high, and a large number of copied images or printer images are output regardless of the environment. Even so, they have found an image forming method capable of maintaining a high quality image.

When the surface hardness of the charging roller is less than 30 degrees, a hydrotalcite compound is likely to be embedded in the latent image carrier, which promotes contamination of the charging roller due to durability and causes image defects due to poor charging in the latter half of durability. Cause undesired.

If the surface hardness of the charging roller exceeds 90 degrees, a sufficient nip between the charging roller and the photosensitive member cannot be ensured and charging failure may occur, which is not preferable.

The roller hardness of the charging roller is measured using an Asker-C rubber hardness meter manufactured by Kobunshi Keiki Co., Ltd. More specifically, with this hardness meter, the average value of arbitrary 5 points of the charging roller is defined as the roller hardness.

The charging roller of the present invention is a JISB.
10-point average surface roughness Rz in 0601 surface roughness standard
Is preferably 5 μm or less, more preferably 3 μm or less. When the average surface roughness (Rz) of the charging roller is made smaller than the average circle-equivalent number diameter D1 (μm) of the toner, it is considered that the substance damaged due to durability enters and accumulates in the concave portion of the charging roller. This is because it is possible to reduce the contamination of the charging roller.

The ten-point average surface roughness Rz of the charging roller surface in the present invention is measured using a surface roughness measuring instrument SE-3400 manufactured by Kosaka Laboratory Ltd. For more details,
With this measuring device, R at any 5 points on the charging roller
z is measured, and the average value of the 5 points is taken as the 10-point average surface roughness.

Next, the hydrotalcite compound used in the present invention will be explained.

The toner used in the present invention must contain toner particles containing at least a binder resin, a colorant and a release agent, and a hydrotalcite compound of the general formula (1) shown below. Is.

[0027]

[Chemical 6] (Wherein 0 <[X = (x1 + x2 + ... + xk)] ≦ 0.
5, Y = (y1 + y2 + ... + yj) = 1-X, and j
And k are integers of 2 or more, M1 ²⁺ , M2 2 ⁺ , ... And Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, A ^n-
Represents an n-valent anion, and m ≧ 0. )

As a result of intensive investigations by the present inventors, the hydrotalcite-based compound has the above-mentioned general formula (1), that is, the divalent metal has two or more kinds and the trivalent metal has two or more kinds. It was found that the object of the present invention can be highly achieved by being a solid solution.

Although the detailed reason is not clear, one of the divalent metal and one type of the trivalent metal is one in which the hydrotalcite compound has the specific structure of the above general formula (1). Case, or two or more divalent metals and one trivalent metal
Compared with the case of the type, the toner has excellent charge stability, and this is a preferred form for the present invention.

The hydrotalcites having the above structure may contain a monovalent alkali metal. Further, plural kinds of anions may exist.

The hydrotalcite compound of the general formula (1) used in the present invention is particularly preferably a compound represented by the following general formula (2).

[0032]

[Chemical 7] (Wherein 0 <[X = (x1 + x2 + ... + xk)] ≦ 0.
5, Y = (y1 + y2 + ... + yj) = 1-X, and j
And k are integers of 2 or more, M2, M3, ... and Mj are Z
n, Ca, Ba, Ni, Sr, Cu, and different metals selected from the group consisting of Fe, L2, L3, ... And L
k is a different metal selected from the group consisting of B, Ga, Fe, Co and In, A ⁿ⁻ is an n-valent anion, and m ≧
It is 0. )

Mg as a divalent metal and Al as a trivalent metal
When it contains, the effect of the present invention of improving the charging stability becomes remarkable. When the content of the divalent metal containing Mg and the content of the trivalent metal containing Al exceeds the above range, the effect relating to the charging stability decreases, and when the content is less than the above range, the environmental stability and It tends to be inferior in storage stability.

The hydrotalcite compound is M
It is more preferable that Ca is contained as a divalent metal other than g, and B and G that are contained as a trivalent metal.
The total amount of e, Fe, and Ga is 0.0003-in atomic ratio.
It is more preferably 0.02.

Examples of A ^n- (n-valent anion) of the hydrotalcites used in the present invention include CO ₃ ²⁻ , OH ⁻ ,
^{C1 -, I -, F -} , Br -, SO 4 -, HCO 3 -, CH 3 C
OO ⁻ and NO ₃ ⁻ are exemplified, and one kind or plural kinds may be present.

The hydrotalcite compound preferably has water in its molecule, and in the general formulas (1) and (2), 0.1 <m <0.6. More preferable.

In the present invention, the addition amount of the hydrotalcites of the general formula (1) is 100 parts by mass of toner particles containing at least a binder resin and a colorant.
The amount is preferably 0.02 to 3.0 parts by mass, more preferably 0.03 to 1.0 part by mass. If it is less than 0.02 parts by mass, the effect of the present invention cannot be obtained, and if it is added in excess of 3.0 parts by mass, the image density unevenness due to the marked deterioration of the fluidity of the toner and proper triboelectrification cannot occur. However, it is not preferable because bad fog is generated in a high temperature and high humidity environment.

The specific surface area of the hydrotalcite used in the present invention is preferably 3.0~150m ² / g, more preferably 7.0~120m ² / g. If it is less than 3.0 m ² / g, a sufficient effect cannot be obtained, and 1
When it exceeds 50 m ² / g, the fluidity of the toner is deteriorated and the image density becomes uneven, which is not preferable.

The specific surface area was determined according to the BET method by using a specific surface area measuring apparatus Auto Soap 1 (manufactured by Yuasa Ionics Co., Ltd.) to adsorb nitrogen gas on the surface of the sample and calculating the specific surface area using the BET multipoint method.

The hydrotalcite used in the present invention is preferably subjected to a hydrophobizing treatment with a surface treating agent in order to stabilize the environment. As a surface treatment agent,
Higher fatty acids, coupling agents, esters, oils such as silicone oil can be used, and higher fatty acids are particularly preferable. Specific examples include stearic acid, oleic acid, and lauric acid.

Next, the release agent used in the present invention will be described.

It is essential that the half width at the endothermic peak of the toner containing the releasing agent used in the present invention is 14 ° C. or less. More preferably, it is 7 ° C. or lower.

In the toner containing the releasing agent, the inventors of the present invention reduce the contamination of the charging roller and the surface of the photosensitive member with the toner constituents by defining the full width at half maximum derived from the releasing agent as described above. Made it possible. One of the reasons why the charging roller is contaminated due to durability is considered as follows.

On the surface of the toner whose shape is deformed or damaged, the release agent is richer than that of the normal toner, and it is presumed that the release agent is highly adhered to the photoconductor and the charging roller. On the other hand, by decreasing the half width of the release agent, the crystallinity of the release agent is increased and at the same time, the hardness is also increased.
Even if the release agent abundance ratio on the toner surface becomes large due to some toner damage due to this, it is considered that the contamination of the charging roller is suppressed.

When the temperature exceeds 14 ° C., since the crystallinity is not high, the hardness of the release agent is soft, and the contamination of the photoreceptor and the charging roller is promoted.

The full width at half maximum of the endothermic peak is the temperature width of the endothermic chart which is half the height of the endothermic peak from the baseline.

The DSC endothermic curve of the release agent in the present invention is measured according to ASTM D3418-82. The release agent in the toner is extracted by an arbitrary method, and the sample is analyzed.

The measurement sample is accurately weighed within the range of 2 to 10 mg. Put this in an aluminum pan and use an empty aluminum pan as a reference.
The measurement is performed at a temperature rising rate of 10 ° C./min between 0 ° C. and normal temperature and normal humidity.

The release agent of the present invention preferably has an endothermic peak value in the DSC endothermic curve of 50 ° C to 120 ° C. A more preferable range is 60 ° C to 100 ° C.

If the endothermic peak value is less than 50 ° C., the self-cohesive force of the wax is weak, so that it is difficult to form the inside or center of the toner particles, and the wax is deposited on the surface of the toner particles during the production of the toner particles. It is easy to contaminate the photoconductor and charging roller.

On the other hand, when the endothermic peak exceeds 120 ° C.,
The wax is unlikely to seep out during fixing, and the fixability at low temperatures and the fixability of secondary colors (red, green, blue) with a large toner development amount are deteriorated. Furthermore, when the toner particles are produced by the direct polymerization method, the solubility in the polymerizable monomer composition is lowered, and the polymerizable monomer composition in the aqueous medium has a particle size of the toner particle size. Wax is deposited during the granulation of droplets, which makes granulation difficult, which is not preferable.

The release agent of the present invention preferably has a weight average molecular weight (Mw) of 300 to 1500. The range of 400 to 1250 is particularly preferable.
When it is less than 300, the wax is likely to be exposed on the surface of the toner particles, the developability is deteriorated, and the fog in a high temperature and high humidity environment is poor. Also, the contamination of the charging roller is significant. 15
When it exceeds 00, the low temperature fixability is deteriorated and the OHT transparency is also deteriorated.

Furthermore, when the weight average molecular weight / number average molecular weight ratio (Mw / Mn) is 1.5 or less, the DS of the wax is reduced.
The maximum peak of the C endothermic curve becomes sharper, the mechanical strength of the toner particles at room temperature is improved, and particularly excellent toner physical properties exhibiting sharp melting characteristics at the time of fixing are obtained.

The molecular weight of the releasing agent is measured by GPC under the following conditions.

(GPC measurement conditions) Apparatus: GPC-150C (manufactured by Waters) Column: GMH-MT 30 cm 2 series (manufactured by Tosoh Corporation) Temperature: 135 ° C. Solvent: o-dichlorobenzene (added 0.1% ionol) Flow rate: 1 0.0 ml / min sample: A 0.15% sample is measured under the condition of 0.4 ml injection or more, and a molecular weight calibration curve prepared from a monodisperse polystyrene standard sample is used for calculating the molecular weight of the sample. Further, it is calculated by performing polyethylene conversion using a conversion formula derived from the Mark-Houwink viscosity formula.

The penetration of the release agent is preferably 15 degrees or less, more preferably 8 degrees or less. When it exceeds 15 degrees, as in the case where the half-value width of the release agent exceeds 14 ° C., the contamination of the photoconductor and the charging roller is promoted.

The penetration of the release agent is measured according to JIS K2235. The measurement temperature is 25 ° C.

The amount of the release agent used in the present invention is 1 to 10 parts by mass based on 100 parts by mass of the binder resin when toner particles are produced by the melt kneading and pulverizing method. good.

In the polymerization method, that is, when the polymerizable monomer composition is used to directly produce toner particles in an aqueous medium, 5 to 40 parts by mass relative to 100 parts by mass of the polymerizable monomer is used. Parts (more preferably 5 to 30 parts by mass) of the releasing agent, and as a result, 5 to 40 parts by mass (more preferably 5 to 40 parts by mass) of the releasing agent per 100 parts by mass of the binder resin produced from the polymerizable monomer. 5 to 30 parts by mass) is preferably contained in the toner particles.

Compared with the dry toner manufacturing method by the melt kneading and pulverization method, in the toner manufacturing method by the polymerization method, since a large amount of the release agent is easily encapsulated in the toner particles by the polar resin, generally, a large amount of the toner is separated as compared with the dry toner manufacturing method. It becomes possible to use a mold agent, which is particularly effective for the offset prevention effect during fixing.

As the release agent used in the toner of the present invention, candelilla wax, carnauba wax, rice wax, wood wax, plant wax such as jojoba oil,
Animal waxes such as beeswax, lanolin and whale wax, mineral waxes such as montan wax, ozokerite and ceresin, paraffin wax, microcrystalline wax, petroleum waxes such as petrolatum, polyolefin waxes, synthetic hydrocarbons such as Fischer-Tropish wax. , Amide wax, ketone wax,
Ester wax is mentioned. If necessary, these may be grafted, blocked, distilled, or the like.

In order to bring out the above effects, a ketone wax and an ester wax are preferable, and an ester wax is particularly preferable when the output of a full color image is taken into consideration.

As the ester wax, the following formula (I) is used.
Those formed from the compounds represented by the formulas (V) to (V) are mentioned as examples, but other compounds may be used.

[0064]

[Chemical 8] (In the formula, a and b are integers from 0 to 4, and a + b is 4. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms, and the number of carbon atoms of R ₁ and R ₂ is The difference is 3 or more: m and n
Is an integer of 0 to 40, and m and n cannot be 0 at the same time. )

[0065]

[Chemical 9] (In the formula, a and b are integers from 0 to 3, and a + b is 1
Through 3. R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms, and the difference in carbon number between R ₁ and R ₂ is 3 or more. R ₃
Is a hydrogen atom or an organic group having 1 or more carbon atoms. However, a
When + b = 2, one of R ₃ is an organic group having 1 or more carbon atoms. k is an integer of 1 to 3. m and n are integers of 0 to 40, and m and n cannot be 0 at the same time. )

[0066]

[Chemical 10] (In the formula, R ₁ and R ₂ are organic groups having 1 to 40 carbon atoms, and R ₁ and R ₃ may or may not be the same.
R ₂ represents an organic group having 1 to 40 carbon atoms. )

[0067]

[Chemical 11] (In the formula, R ₁ and R ₃ are organic groups having 1 to 40 carbon atoms, and R ₁ and R ₃ may or may not be the same.

[0068]

[Chemical 12] (In the formula, a is an integer of 0 to 4, b is an integer of 1 to 4, and a + b is 4. R ₁ has 1 to 4 carbon atoms.
0 is an organic group. m and n are integers of 0 to 40, and m and n cannot be 0 at the same time. )

In the toner of the present invention, a more preferable effect can be added by using a charge control agent in combination.

The charge control agent will be described below.

A method of using a charge control agent for further improving the chargeability of the toner is generally widely known, but in the toner to which the hydrotalcite compound of the present invention is externally added, an oxycarboxylic acid type charge is used. It has been found that the use of a control agent is particularly effective in suppressing desorption of hydrotalcite compounds. The detailed reason for this is unknown, but it is considered as follows.

Since the hydrotalcite compound is originally positively charged, unless it is firmly held by the Coulomb force and the adhesive force with the toner, it tends to be electrostatically adsorbed to the charging roller when a high negative bias is applied in the charging step. have. However, when an oxycarboxylic acid-based charge control agent is present on the surface of the toner particles, it plays a role of preventing the hydrotalcite-type compound from being carried to the charging roller due to its negative charging property. It is considered that the acid-accepting effect is exerted and the desorption from the toner is suppressed by the interaction with the oxycarboxylic acid.

In the present invention, the mass X (mg / g) of the oxycarboxylic acid extracted from 1 g of the toner with a 0.1 mol / liter sodium hydroxide aqueous solution.
Is preferably X = 0.10 to 20.0 mg / g (based on the mass of the toner), and more preferably 0.10 to 1
5.0 mg / g is good.

When the amount is less than 0.10 mg / g, sufficient interaction with the hydrotalcite compound is not exhibited, and there is a concern that charging roller contamination may occur due to liberation of the hydrotalcite compound in the latter half of durability. Absent.

If it exceeds 20.0 mg / g, the charging performance in a high temperature and high humidity environment will deteriorate, so that fog is unfavorable at the time of initial image output after being left in a high temperature and high humidity environment.

The oxycarboxylic acid according to the present invention includes
Although known compounds can be used, compounds represented by the following formulas (1) and (2) are preferably used from the viewpoint of charge imparting ability.

[0077]

[Chemical 13] [In the above formula (1), (A) is selected from the following group and X ₁
Represents a hydrogen atom, a sodium atom, a potassium atom, ammonium or an aliphatic ammonium. ]

[0078]

[Chemical 14]

[0079]

[Chemical 15] [In the above formula (2), X ₂ represents a hydrogen atom, a sodium atom, a potassium atom, ammonium, or an aliphatic ammonium, and R ₄ represents a C _{1 to} C ₂₂ alkyl group, an alkenyl group, or an aryl group. , R ₅ is a hydrogen atom, C ₁ -C
_{22 represents} an alkyl group, an alkenyl group, an aryl group or an alkoxy group. ]

Among the oxycarboxylic acids represented by the above formulas (1) and (2), those preferably used in the present invention are oxycarboxylic acids having an aromatic ring,
Examples thereof include monoalkyl aromatic oxycarboxylic acid and dialkyl aromatic oxycarboxylic acid. In particular, alkylsalicylic acid represented by salicylic acid, ditert-butylsalicylic acid and 5-tert-octylsalicylic acid, hydroxynaphthoic acid, benzylic acid and the like are preferably used in the present invention.

Preferred examples are shown below.

[0082]

[Chemical 16]

[0083]

[Chemical 17]

[0084]

[Chemical 18]

[0085]

[Chemical 19]

[0086]

[Chemical 20]

In the present invention, from the toner, 0.1 mo
The method for calculating the amount X of oxycarboxylic acid extracted with a 1 / liter sodium hydroxide aqueous solution will be described below.

50 ml of 0.1 mol / liter aqueous sodium hydroxide solution containing 0.04 g of Contaminone N (manufactured by Wako Pure Chemical Industries, Ltd.) as a dispersant was prepared in separate containers, and 1 g of toner was contained in each container. Weigh and add, stir at 50 rpm using a stirrer, and disperse uniformly. After dispersion treatment for 3 hours, it was filtered using a membrane filter (pore size: 0.45 μm), and the absorption spectrum of the obtained filtrate was measured by a spectrophotometer to find the maximum value of the maximum absorption peak of oxycarboxylic acid. And the difference from the baseline. From the obtained results, the amount X of oxycarboxylic acid in the toner was calculated using a predetermined calibration curve. The absorption spectrum of oxycarboxylic acid is, for example, 28
It appears in the range of 0 to 350 nm.

In the toner of the present invention, a known charge control agent is blended in the toner particles together with the above-mentioned oxycarboxylic acid or its metal complex compound for the purpose of finely adjusting the charging speed and the charging amount of the toner ( They can be used together (internally added) or mixed with toner particles (externally added).

The following substances control the toner to be negatively charged.

For example, organic metal compounds and chelate compounds are effective, and there are monoazo metal compounds, acetylacetone metal compounds, aromatic oxycarboxylic acids, aromatic dicarboxylic acids, oxycarboxylic acids and dicarboxylic acid type metal compounds. Other examples include aromatic oxycarboxylic acids, aromatic mono- and polycarboxylic acids and their metal salts, anhydrides, esters, and phenol derivatives such as bisphenol. Further, a urea derivative, a metal-containing salicylic acid-based compound, a metal-containing naphthoic acid-based compound, a boron compound, a quaternary ammonium salt, a calixarene, a resin-based charge control agent and the like can be mentioned.

The following substances control the toner to be positively charged.

Nigrosine modified products of nigrosine and fatty acid metal salts, guanidine compounds, imidazole compounds, quaternary ammonium salts such as tributylbenzylammonium-1-hydroxy-4-naphthosulfonate, tetrabutylammonium tetrafluoroborate,
And onium salts such as phosphonium salts which are analogs thereof, lake pigments thereof, triphenylmethane dyes and lake pigments thereof (as a laker, phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid) , Lauric acid, gallic acid, ferricyanide, ferrocyanide, etc.), metal salts of higher fatty acids; dibutyltin oxide, dioctyltin oxide, diorganotin oxides such as dicyclohexyltin oxide; dibutyltin borate, dioctyltin borate, dicyclohexyltin borate. Examples thereof include diorgano tin borates, resin type charge control agents and the like. These can be used alone or in combination of two or more.

The charge control agent is used in an amount of 0.01 to 20 parts by mass, preferably 0.5 to 10 parts by mass, per 100 parts by mass of the binder resin.

Next, the circularity of the toner of the present invention will be described.

The number-based circle equivalent diameter-circularity measured by the toner particle flow measuring device of the present invention has an average circularity of 0.950 to 0.999 in the scattergram.
Is preferred. More preferable average circularity and standard deviation of circularity are 0.950 to 0.999 and preferably less than 0.040, and more preferably 0.950 to 0.9.
95, preferably 0.015 or more and less than 0.035, and more preferably 0.970 to 0.99.
It is 5 and preferably 0.015 or more and less than 0.035.

When the average circularity is less than 0.950,
Since the shape of the toner becomes considerably irregular, the transfer efficiency of the toner during continuous paper feeding deteriorates and the toner consumption increases.

If the average circularity exceeds 0.999, reproducibility and yield are significantly deteriorated in terms of manufacturing, leading to cost increase.

When the standard deviation of circularity exceeds 0.040, the shape distribution of the toner is widened, so that the uniform transfer is deteriorated and the halftone reproducibility is deteriorated.

The equivalent circle diameter of the toner, the circularity, and their frequency distribution in the present invention are used as a simple method for quantitatively expressing the shape of toner particles. In the present invention, the flow type particle image is used. It measured using the measuring device FPIA-1000 type (made by Toa Medical Electronics Co., Ltd.), and calculated using the following formula.

[0101]

[Equation 1]

Here, the “particle projection area” is the area of the binarized toner particle image, and the “perimeter of the particle projection image”.
Is defined as the length of the contour line obtained by connecting the edge points of the toner particle image.

The circularity in the present invention is an index showing the degree of unevenness of the toner particles, and shows 1.000 when the toner particles are completely spherical, and the more complicated the surface shape, the more
The circularity has a small value.

In the present invention, the circle-equivalent number average diameter D1 (μ
m) and the particle size standard deviation SDd are calculated from the following equations, where di is the particle size (center value) at the dividing point i of the particle size distribution and fi is the frequency.

[0105]

[Equation 2]

Further, regarding the average circularity C and the circularity standard deviation SDc, which mean the average value of the circularity frequency distribution, if the circularity (center value) at the dividing point i of the particle size distribution is ci and the frequency is fci, It is calculated from the following formula.

[0107]

[Equation 3]

As a specific measuring method, 10 ml of ion-exchanged water from which impure solids and the like have been removed in advance is prepared in a container, and a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant into it. Then, 0.02 g of a measurement sample is further added and uniformly dispersed. As a dispersing means, an ultrasonic dispersing machine UH-50 type (manufactured by SMT) equipped with a titanium alloy chip of 5φ as a vibrator is used, and dispersion treatment is performed for 5 minutes to obtain a dispersion liquid for measurement.
At that time, the dispersion liquid is appropriately cooled so that the temperature of the dispersion liquid does not exceed 40 ° C.

To measure the shape of toner particles, a flow type particle image measuring apparatus "FPIA-1000" (manufactured by Toa Medical Electronics Co., Ltd.) was used, and the toner particle concentration at the time of measurement was 3000 to 10,000 particles / μl. Then, the concentration of the dispersion liquid is readjusted and 1,000 or more toner particles are measured. After the measurement, the equivalent circle diameter of the toner particles, the circularity frequency distribution, and the like are obtained using this data.

In the present invention, in order to faithfully develop finer latent image dots for higher image quality, the toner particles preferably have a weight average diameter of 4 μm to 10 μm. In the case of toner particles having a weight average particle diameter of less than 4 μm, a large amount of residual toner remains on the photosensitive member due to a decrease in transfer efficiency, and moreover, it tends to cause uneven image unevenness due to fog and transfer failure. It is not preferable for the toner to be used. The weight average diameter of the toner particles is 10 μm.
When it exceeds, scattering of characters and line images is likely to occur.

For the average particle size and particle size distribution of the toner, Coulter Counter TA-II type or Coulter Multisizer (manufactured by Coulter Co.) is used, and an interface (manufactured by Nikkaki Co., Ltd.) for outputting number distribution and volume distribution and PC9
801 personal computer (manufactured by NEC) is connected, and the electrolyte is 1% NaCl using primary sodium chloride.
Prepare an aqueous solution. For example, ISOTON R-II
(Manufactured by Coulter Scientific Japan) can be used. As the measuring method, the electrolytic aqueous solution 100 to 1 is used.
0.1 to 5 ml of a surfactant (preferably alkylbenzene sulfonate) as a dispersant is added to 50 ml,
Further, 2 to 20 mg of the measurement sample is added. The electrolytic solution in which the sample was suspended was subjected to dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and the volume and number of toner particles having a size of 2 μm or more were measured using a 100 μm aperture as an aperture with the Coulter Counter TA-II type. The volume distribution and number distribution were calculated. Then, the volume-based weight average particle diameter (D4) obtained from the volume distribution and the number-based length average particle diameter (D1) obtained from the number distribution according to the present invention were obtained.

The toner of the present invention is used by externally adding at least one kind of inorganic fine powder selected from titania, alumina, silica or a complex oxide thereof for the purpose of further improving fluidity and chargeability. be able to. The inorganic fine powder preferably has a specific surface area (BET) of 20 to 400 m ² / g. It is preferable that the particle size of the inorganic fine powder is smaller than the particle size of the hydrotalcite-based compound because embedding of the inorganic fine powder into the toner due to durability damage is suppressed.

Further, the surface-treated product of the inorganic fine powder can be used as an external additive. Examples of the surface treatment agent include a silane coupling agent, a silylating agent, a titanium coupling agent, and a silicone oil, but preferably a silane coupling agent, a silylating agent, and a silicone oil are used. You may use together.

The amount of the fine powder added to the toner is 0.05 to 5 parts by weight, preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the toner. The amount of the inorganic fine powder is 0.
When the amount is less than 05 parts by mass, the fluidity of the toner is poor and the charging characteristics are likely to be non-uniform. Further, since the regulated amount of toner on the toner carrier tends to be unstable and the coat tends to be unstable, development defects such as image fog and toner leakage are likely to occur. On the other hand, when the amount of the inorganic fine powder exceeds 5.0 parts by mass, toner contamination on the charging roller, the surface of the photoconductor, and the surface of the developer carrier is likely to occur, and the image is continuously printed on the surface of the photoconductor in continuous printing. It is not preferable because fusing or contamination of the lower layer of the developer carrier causes adverse effects on development such as fusion to the latent image carrier.

The toner of the present invention has a fluorescent X-ray intensity ratio (Mg / Si) of Mg to Si contained in the toner of 1.5 × 10 ^{−3 to} 100 × 10 ⁻³ and a fluorescent X-ray of Al. Strength ratio (Al / Si) is 1.0 × 10 ^{-2 to} 100 × 10
^-2 is preferable.

The strength ratio of Mg to Si is 1.5 × 10.
^If it is less than ^-3 , the effect of hydrotalcite is canceled out by the silica particles, causing charging failure in a high temperature and high humidity environment.
If it exceeds 00 × 10 ⁻³ , the fluidity is deteriorated due to excessive hydrotalcite, which is unfavorable because charging failure, accompanying uneven density and fog are deteriorated.

For the same reason, if the fluorescent X-ray intensity ratio of Al to Si is less than 1.0 × 10 ⁻² , charging failure will occur, and if it exceeds 100 × 10 ⁻² , charging failure will occur, and density unevenness associated therewith. However, the fog tends to deteriorate, which is not preferable.

For the measurement of fluorescent X-rays, RIX3000 manufactured by Rigaku Denki Kogyo Co., Ltd. was used, Rh was used as a target, and the voltage and current were measured at 50 kV and 50 mA. Si K
For the α-ray intensity measurement, PET was used for the dispersive crystal and a proportional counter was used for the detector. For the Kα ray intensity measurement of Mg, a TAP was used for the dispersive crystal and a proportional counter was used for the detector. Al Kα ray intensity measurement is 40kV
At 90 mA, PET was used as a dispersive crystal and a proportional counter was used as a detector. The intensity ratio of fluorescent X-rays in the present invention means the X-ray net intensity (KK) of Mg by measuring the Kα-ray net intensity (KCPS) of each element of Si, Mg and Al.
CPS) / Si X-ray net intensity (KCPS) and Al
X-ray net strength (KCPS) / Si X-ray net strength (KCPS) was calculated to obtain the ratio.

Further, in the present invention, the following inorganic powder may be added in order to improve the developability and durability. Metal oxides such as magnesium, zinc, aluminum, cerium, cobalt, iron, zirconium, chromium, manganese, strontium, tin, antimony; complex metal oxides such as calcium titanate, magnesium titanate, strontium titanate; barium sulfate, Metal salts such as calcium carbonate, magnesium carbonate, aluminum carbonate;
Clay minerals such as kaolin; Phosphoric acid compounds such as apatite;
Silicon compounds such as silica, silicon carbide, and silicon nitride; carbon powders such as carbon black and graphite.

For the same purpose, the following organic particles and composite particles can be added. Resin particles such as polyamide resin particles, silicone resin particles, silicone rubber particles, urethane particles, melamine-formaldehyde particles, and acrylic particles; rubber, wax, fatty acid compounds, resins, etc. and metals,
Composite particles composed of metal oxides, salts, inorganic particles such as carbon black; fluororesins such as polyfluoroethylene and polyvinylidene fluoride; fluorine compounds such as carbon fluoride; fatty acid metal salts such as zinc stearate; fatty acids And fatty acid derivatives such as fatty acid esters; molybdenum sulfide, amino acids and amino acid derivatives.

These additives may be used alone, or
You may use together two or more. Further, a hydrophobic treatment (oil, coupling) may be performed if necessary.

The stirring method suitable for producing the toner of the present invention is not particularly limited as long as it is mechanically externally attached, and a known stirring device can be used. A Henschel mixer or a homogenizer is preferably used, and more preferably, a Henschel mixer can be used.

Other constituent substances used in the toner of the present invention will be described.

First, the binder resin of the toner will be described.

The binder resin of the toner used when the toner of the present invention is manufactured by a pulverization method is polystyrene;
Styrene-substituted homopolymers such as poly-p-chlorostyrene and polyvinyltoluene; styrene-p-chlorostyrene copolymers, styrene-vinyltoluene copolymers, styrene-vinylnaphthalene copolymers, styrene-acrylic acid esters Copolymer, styrene-methacrylic acid ester copolymer, styrene-α-chloromethyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-vinyl methyl ether copolymer, styrene-vinyl ethyl ether copolymer, Styrene-based copolymers such as styrene-vinyl methyl ketone copolymer, styrene-butadiene copolymer, styrene-isoprene copolymer, styrene-acrylonitrile-indene copolymer; acrylic resin, methacrylic resin, polyvinyl acetate, silicone Resin, polys Le resins, polyamide resins, furan resins, epoxy resins, xylene resins.

These resins are used alone or as a mixture.

As the main component of the binder resin, a styrene copolymer which is a copolymer of styrene and another vinyl monomer is preferable from the viewpoint of developability and fixability.

Comonomers for the styrene monomer of the styrene copolymer include acrylic acid, methyl acrylate, ethyl acrylate, butyl acrylate, dodite acrylate, octyl acrylate, 2-ethylhexyl acrylate, phenyl acrylate, methacrylic acid. Acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, monocarboxylic acid having a double bond such as acrylamide or a substitution product thereof; maleic acid,
Dicarboxylic acids having a double bond such as butyl maleate, methyl maleate and dimethyl maleate and substituted products thereof; vinyl esters such as vinyl chloride, vinyl acetate and vinyl benzoate; ethylene such as ethylene, propylene and butylene. Examples include olefins; vinyl ketones such as vinyl methyl ketone and vinyl hexyl ketone; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether. These vinyl monomers are used alone or in combination of two or more.

The styrene copolymer is preferably crosslinked with a crosslinking agent such as divinylbenzene in order to widen the fixing temperature range of the toner and improve the offset resistance.

As the polymerizable monomer used when the toner of the present invention is produced by a polymerization method, a vinyl-based polymerizable monomer capable of radical polymerization is used. As the vinyl-based polymerizable monomer, a monofunctional polymerizable monomer or a polyfunctional polymerizable monomer can be used.

Monofunctional polymerizable monomers include styrene; α-methylstyrene, β-methylstyrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, 2,4-dimethylstyrene, p- n-butyl styrene, p-tert-butyl styrene, pn-hexyl styrene, pn-octyl styrene, pn-nonyl styrene, pn-decyl styrene, pn-dodecyl styrene, p-methoxy Styrene, styrene derivatives such as p-phenylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, iso-propyl acrylate, n-butyl acrylate, iso
-Butyl acrylate, tert-butyl acrylate, n-amyl acrylate, n-hexyl acrylate, 2-ethylhexyl acrylate, n-octyl acrylate, n-nonyl acrylate, cyclohexyl acrylate, benzyl acrylate, dimethyl phosphate ethyl acrylate, diethyl phosphate ethyl Acrylic polymerizable monomers such as acrylate, dibutyl phosphate ethyl acrylate, 2-benzoyloxyethyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, iso-propyl methacrylate, n-butyl methacrylate, iso-butyl methacrylate, tert
-Butyl methacrylate, n-amyl methacrylate,
Methacrylic polymerizable monomers such as n-hexyl methacrylate, 2-ethylhexyl methacrylate, n-octyl methacrylate, n-nonyl methacrylate, diethyl phosphate ethyl methacrylate, and dibutyl phosphate ethyl methacrylate; methylene aliphatic monocarboxylic acid ester; acetic acid Vinyl esters such as vinyl, vinyl propionate, vinyl butyrate, vinyl benzoate, vinyl formate; vinyl ethers such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether; vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, vinyl isopropyl ketone Can be mentioned.

As the polyfunctional polymerizable monomer, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate, 1,6
-Hexanediol diacrylate, neopentyl glycol diacrylate, tripropylene glycol diacrylate, polypropylene glycol diacrylate, 2,2'-bis (4- (acryloxydiethoxy) phenyl) propane, trimethylolpropane triacrylate, tetramethylolmethane Tetraacrylate, ethylene glycol dimethacrylate, diethylene glycol dimethacrylate, triethylene glycol dimethacrylate, tetraethylene glycol dimethacrylate, polyethylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate,
1,6-hexanediol dimethacrylate, neopentyl glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis (4- (methacryloxydiethoxy) phenyl) propane, 2,
2'-bis (4- (methacryloxy polyethoxy) phenyl) propane, trimethylolpropane trimethacrylate, tetramethylolmethane tetramethacrylate, divinylbenzene, divinylnaphthalene, divinyl ether and the like can be mentioned.

In the present invention, the above monofunctional polymerizable monomers may be used alone or in combination of two or more kinds, or
The monofunctional polymerizable monomer and the polyfunctional polymerizable monomer described above are used in combination. The polyfunctional polymerizable monomer can also be used as a crosslinking agent.

An oil-soluble initiator and / or a water-soluble initiator is used as a polymerization initiator used in the above-mentioned polymerization of the polymerizable monomer. For example, as the oil-soluble initiator, 2,2'-azobisisobutyronitrile, 2,2 '
-Azobis-2,4-dimethylvaleronitrile, 1,
Azo compounds such as 1′-azobis (cyclohexane-1-carbonitrile) and 2,2′-azobis-4-methoxy-2,4-dimethylvaleronitrile; acetylcyclohexylsulfonyl peroxide, diisopropylperoxycarbonate, decanoylperoxide oxide,
Lauroyl peroxide, stearoyl peroxide, propionyl peroxide, acetyl peroxide, t-butylperoxy-2-ethylhexanoate, benzoyl peroxide, t-butylperoxyisobutyrate, cyclohexanone peroxide, methyl ethyl ketone peroxide, Examples thereof include peroxide-based initiators such as dicumyl peroxide, t-butyl hydroperoxide, di-t-butyl peroxide and cumene hydroperoxide.

As the water-soluble initiator, ammonium persulfate, potassium persulfate, 2,2'-azobis (N, N'-
Dimethyleneisobutyroamidine) hydrochloride, 2,2′-azobis (2-aminodinopropane) hydrochloride, azobis (isobutylamidine) hydrochloride, 2,2′-azobisisobutyronitrile sodium sulfonate, sulfuric acid Examples include ferrous iron or hydrogen peroxide.

In the present invention, in order to control the degree of polymerization of the polymerizable monomer, it is possible to further add and use a chain transfer agent, a polymerization inhibitor or the like.

As the crosslinking agent used in the toner of the present invention, a compound having two or more polymerizable double bonds is used. For example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene; carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate and 1,3-butanediol dimethacrylate; divinylaniline; And divinyl compounds such as divinyl ether, divinyl sulfide and divinyl sulfone; and compounds having 3 or more vinyl groups. These are used alone or as a mixture.

When the toner of the present invention is a polymerized toner, a condensation resin may be added. Examples of the condensed resin of the present invention include polyester, polycarbonate, phenol resin, epoxy resin, polyamide, and cellulose. More preferably, polyester is desired due to the variety of materials. 0.0 per 100 parts by mass of binder resin
It is preferable to use 1 to 20 parts by mass, more preferably 0.5 to 10 parts by mass.

As the colorant used in the toner of the present invention, carbon black, a magnetic substance, and a yellow / magenta / cyan colorant shown below, which are toned in black, are used.

As the yellow colorant, as a pigment system, compounds represented by condensed azo compounds, isoindolinone compounds, anthraquinone compounds, azo metal complex methine compounds, and allylamide compounds are used. Specifically, C.I. I. Pigment Yellow 3, 7, 1
0, 12, 13, 14, 15, 17, 23, 24, 6
0, 62, 74, 75, 83, 93, 94, 95, 9
9, 100, 101, 104, 108, 109, 11
0, 111, 117, 123, 128, 129, 13
8, 139, 147, 148, 150, 166, 16
8, 169, 177, 179, 180, 181, 18
3, 185, 191: 1, 191, 192, 193, 1
99 and the like are preferably used. As the dye system, for example,
C. I. solventYellow33, 56, 7
9, 82, 93, 112, 162, 163, C.I. I. d
isperse Yellow 42, 64, 201, 2
11 and the like.

As the magenta colorant, a condensed azo compound, a diketopyrrolopyrrole compound, an anthraquinone, a quinacridone compound, a basic dye lake compound, a naphthol compound, a benzimidazolone compound, a thioindigo compound and a perylene compound are used. Specifically, C.I.
I. Pigment Red 2, 3, 5, 6, 7, 23, 4
8: 2, 48: 3, 48: 4, 57: 1, 81: 1, 1
22, 146, 166, 169, 177, 184, 18
5, 202, 206, 220, 221, 254, C.I.
I. Pigment Violet 19 is particularly preferable.

As the cyan colorant, a phthalocyanine compound and its derivative, an anthraquinone compound, a basic dye lake compound and the like can be used. Specifically, C.I. I. Pigment Blue 1, 7, 15, 15: 1, 15: 2, 1
5: 3, 15: 4, 60, 62, 66 and the like are particularly preferably used.

These colorants may be used alone or in combination, and may be used in the form of solid solution. The colorant of the present invention is selected in terms of hue angle, saturation, lightness, weather resistance, OHP transparency, and dispersibility in toner. The colorant is added in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the resin.

The toner manufacturing method of the present invention will be described below.

When the toner of the present invention is a pulverized toner, at least a binder resin and a colorant are kneaded and uniformly dispersed by using a pressure kneader, an extruder, a media disperser or the like, A method of producing toner particles by mechanically or in a jet stream to collide with a target to finely pulverize it to a desired toner particle size, and further after a classification step, to obtain toner particles having a desired circularity using mechanical means, There is a method of performing a wet or dry thermal spheroidizing treatment after the above pulverization.

When the toner of the present invention is a polymerization method,
Although not particularly limited, the Japanese Patent Publication No. 36-102
31, JP-A-59-53856, JP-A-5-
A method of directly producing a toner by using the suspension polymerization method described in JP-A 9-61842; a monomer is soluble in a monomer and is directly polymerized in the presence of a water-soluble polymerization initiator to produce toner particles. Production of toner particles by an emulsion polymerization method typified by a soap-free polymerization method can be mentioned. In addition, an interfacial polymerization method such as a microcapsule manufacturing method, an in-situ polymerization method,
The production of the coacervation method and the like is also included. Furthermore, JP-A-62-106473 and JP-A-63-1
As disclosed in Japanese Patent No. 86253, at least 1
An interface association method for aggregating at least one kind of fine particles to obtain particles having a desired particle size is also included.

A suspension polymerization method is particularly preferable because it allows toner particles having a small particle diameter to be easily obtained. Further, a seed polymerization method in which a monomer is further adsorbed on the obtained polymer particles and then the resultant is polymerized using a polymerization initiator can also be suitably used in the present invention. At this time, it is also possible to disperse or dissolve the polar compound in the adsorbed monomer.

In the case of suspension polymerization, it is usually preferable to use 300 to 3000 parts by mass of water as a dispersion medium with respect to 100 parts by mass of the monomer composition. As the dispersant used, for example, as an inorganic oxide, tricalcium phosphate,
Magnesium phosphate, aluminum phosphate, zinc phosphate, calcium carbonate, magnesium carbonate, calcium hydroxide, magnesium hydroxide, aluminum hydroxide, calcium metasilicate, calcium sulfate, barium sulfate, bentonite, silica, alumina, sodium dodecyl sulfate, etc. Is mentioned. As the organic compound, for example, polyvinyl alcohol, gelatin, methyl cellulose, methyl hydroxypropyl cellulose, ethyl cellulose, sodium salt of carboxymethyl cellulose, starch and the like are used. These dispersants or dispersion aids are preferably used in an amount of 0.1 to 5.0 parts by mass with respect to 100 parts by mass of the polymerizable monomer. In order to make these dispersants finer, 0.001 to 0.1% by mass of a surfactant may be used in combination. Specifically, commercially available nonionic, anionic and cationic surfactants can be used. For example, sodium dodecyl sulfate, sodium tetradecyl sulfate, sodium pentadecyl sulfate, sodium octyl sulfate, sodium oleate, sodium laurate, potassium stearate, calcium oleate and the like are preferably used.

An image forming method suitable for the present invention will be described below.

The toner carrier in the image forming method of the present invention is not particularly limited, but a rigid roller is used as the toner carrier and the photosensitive member is a flexible member such as a belt, or a rigid member is used as the photosensitive member. It is possible to use a flexible toner carrier such as an elastic body.

An elastic roller is preferably used when it is placed in pressure contact with a rigid photoconductor.

The hardness of the elastic roller is preferably about 30 to 90 degrees (JIS A), and more preferably 25 to 85 degrees, from the viewpoint of achieving both developability and durability. As the material of the elastic roller, known materials and structures can be used. Particularly, a solid rubber elastic body such as silicone rubber, urethane rubber, NBR, or a foamed elastic body of these is preferably used. Further, a well-known multilayer structure roller having a coat layer different from the central portion on the surface can be used.
Further, a known surface treatment may be applied for the purpose of imparting chargeability and transportability.

Regarding the surface shape of the toner carrier, it is preferable to control the surface roughness of the toner carrier in order to achieve both high image quality and high durability. As the surface roughness of the toner carrier, for example, Ra (μm) “JIS B 0601” is 0.2 to
When set to 3.0, both high image quality and high durability can be achieved. When the surface roughness Ra of the toner carrier exceeds 3.0, not only is it difficult to reduce the thickness of the developer layer on the toner carrier, but also the chargeability of the developer is not improved, so that the image quality is improved. I can't hope. When it is 3.0 or less, the developer carrying ability on the surface of the toner carrier is suppressed, the developer layer on the toner carrier is thinned, and the number of times of contact between the toner carrier and the developer is increased. Therefore, the chargeability of the developer is also improved and the image quality is synergistically improved. On the other hand, if the surface roughness Ra is less than 0.2, it becomes difficult to control the developer coating amount.

The toner on the toner carrier is regulated by a developing blade arranged so as to be in pressure contact with the surface of the toner carrier, and a toner layer is formed on the toner carrier.

It is preferable that the pressure for bringing the developing blade into pressure contact with the surface of the toner carrier to regulate the layer thickness on the toner carrier is appropriately adjusted so that the thickness of the toner coat layer is kept constant. As the material of the toner coat amount regulating member, it is preferable to select a friction charging series material suitable for charging the toner to a desired polarity, such as silicone rubber, urethane rubber, rubber elastic body such as NBR, polyethylene terephthalate. Synthetic resin elastic bodies such as, and metallic elastic bodies such as stainless steel, steel, and phosphor bronze can be used, and composites thereof, for example, those in which a resin or rubber is bonded to the sleeve abutting portion on the metallic elastic body, Alternatively, it may be coated.

Further, an organic substance or an inorganic substance may be added to the elastic regulating member, and may be melt-mixed or dispersed. For example, metal oxides, metal powders, ceramics, carbon allotropes, whiskers, inorganic fibers, dyes, pigments,
The chargeability of the toner can be controlled by adding a surfactant or the like. In particular, when the elastic body is a molded body such as rubber or resin, silica, alumina, titania, tin oxide, zirconia oxide, fine powder of metal oxide such as zinc oxide,
It is also preferable to include carbon black, a charge control agent generally used in toner, and the like.

When the conductive regulating member and the toner carrier are used in combination, it is also preferable to apply a DC electric field and / or an AC electric field between the regulating member and the toner carrier. By applying such an electric field, uniform thin layer coating and uniform chargeability are improved, and sufficient image density can be achieved and a high-quality image can be obtained.

Further, when durability is required for the elastic regulating member and the toner carrier, it is preferable that the metal elastic body is laminated with resin or rubber so as to abut on the sleeve abutting portion, or the coating is applied. .

The photoconductor of the present invention includes a-Se and Cd.
A known photosensitive drum or photosensitive belt having a photoconductive insulating material layer such as s, ZnO ₂ , OPC, or a-Si is preferably used.

Of these, OPC is particularly preferably used. The binder resin for the organic photosensitive layer in the OPC photoreceptor is not particularly limited, and known binder resins can be used, but from the viewpoint of toner chargeability, transferability, and filming, a polycarbonate resin or a polyarylate resin can be used. Is preferred.

The charging means of the present invention is a charging roller having a conductive elastic layer. This will be described below with reference to the drawings.

In FIG. 1, 2 is a charging member, 2a is a conductive support, 2b is an elastic layer, 2c is a resistance control layer, and 2d is a surface layer. The charging roller may have a structure of the elastic layer 2b and the surface layer 2d without the resistance control layer 2c.

The conductive support 2a used in the present invention is
Metals such as iron, copper, stainless steel, aluminum and nickel can be used. Further, these metal surfaces may be subjected to a plating treatment for the purpose of preventing rust and imparting scratch resistance, but it is necessary that the conductivity is not impaired.

In the charging roller 2, the elastic layer 2b is provided with appropriate elasticity in order to ensure good uniform adhesion of the charging roller 2 to the photosensitive member 1.

The conductivity of the elastic layer 2b is adjusted by adding conductive particles such as carbon black or a conductive agent such as an alkali metal salt and an ammonium salt to an elastic material such as rubber. Elasticity is adjusted by the addition of process oils and plasticizers and the like. Specific examples of the elastic material of the elastic layer 2b include natural rubber, ethylene propylene diene methylene rubber (EPDM), styrene-butadiene rubber (SBR), silicone rubber, urethane rubber, epichlorohydrin rubber, isoprene rubber (IR), butadiene rubber. (BR), synthetic rubbers such as nitrile-butadiene rubber (NBR) and chloroprene rubber (CR), and further resins such as polyamide resin, polyurethane resin, silicone resin and fluororesin. Moreover, you may use the foam of the above-mentioned elastic material for the elastic layer 2b.

The electric resistance of the elastic layer is 1 × 10 ³ to 1
Preferably it has a conductivity in the range of × ¹⁰ 10 [Ωcm]. Further, the film thickness depends on the diameter of the conductive support and is not particularly limited.

The surface layer 2d is often provided to prevent bleeding out of the plasticizer or the like in the elastic layer 2b onto the surface of the charging roller, and to maintain the smoothness and smoothness of the surface of the charging roller. The surface layer 2d is provided by coating or coating a tube.

When the surface layer 2d is provided by coating, specific materials include polyamide resins, polyurethane resins, acrylic resins, fluororesins and silicone resins, as well as epichlorohydrin rubber, urethane rubber,
Examples thereof include chloroprene rubber and acrylonitrile rubber. As a coating method, a dip coating method, a roll coating method, a spray coating method and the like are preferable.

When the surface layer 2d is provided by covering the tube, specific materials are nylon 12, PFA (tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin), PVDF (polyvinylidene fluoride). , FEP (tetrafluoroethylene-6 fluoropropylene copolymer resin), and further thermoplastic elastomers such as polystyrene type, polyolefin type, polyvinyl chloride type, polyurethane type, polyester type and polyamide type.

The tube may be a heat-shrinkable tube or a non-heat-shrinkable tube. Surface layer 2d
In order to have appropriate conductivity, conductive particles such as carbon black and carbon graphite and conductive agents such as conductive metal oxides such as conductive titanium oxide, conductive zinc oxide and conductive tin oxide should be used. Used.

The electric resistance of the surface layer is 1 × 10 ⁶ to 1
It is preferably in the range of × 10 ¹⁴ [Ωcm]. The film thickness is preferably 2 to 500 μm.
More preferably, it is 2 to 250 μm.

The resistance control layer 2c is often provided to control the resistance of the charging member. Specific examples of the material for the resistance control layer 2c include resins such as polyamide resin, polyurethane resin, fluororesin and silicone resin, as well as epichlorohydrin rubber, urethane rubber, chloroprene rubber and acrylonitrile rubber. Resistance control layer 2c
Also, for the purpose of adjusting the resistance, conductive particles such as carbon black and carbon graphite, conductive metal oxides such as conductive titanium oxide, conductive zinc oxide and conductive tin oxide, or alkali metal salts and ammonium salts, etc. The conductive agent can be dispersed.

The resistance control layer 2c is also provided by coating or coating a tube.

The electric resistance of the resistance control layer is 1 × 10 ^6.
It is preferably in the range of 1 × ¹⁰ [Ωcm]. Further, the film thickness is preferably 10 to 1000 μm. More preferably, it is 10 to 750 μm.

The volume resistivity in the present invention is measured by JI
It was carried out according to SK 6911.

Next, the image forming method of the present invention will be specifically described below with reference to the accompanying drawings.

In FIG. 2, 140 is a developing device and 100
Is a photosensitive member, 127 is a transfer target such as paper, 114 is a transfer member, 126 is a fixing pressure roller, 128 is a fixing heating roller, 117 is a primary charging member that contacts the photosensitive member 100 and directly charges it. Show.

A bias power source 131 is connected to the primary charging member 117 so as to uniformly charge the surface of the photoconductor 100.

The developing device 140 contains the toner 142, and is provided with the toner carrier 104 which comes into contact with the photosensitive member 100 and rotates in the direction of the arrow. Further, the developing blade 143 for toner amount regulation and charge imparting is attached to the toner carrier 104 and the toner carrier 104 is attached.
Also provided is an application roller 141 that rotates in the direction of the arrow in order to impart charge to the toner by friction with. A developing bias power source 133 is connected to the toner carrier 104. The bias power source 132 is also connected to the coating roller 141, and a voltage is set to the negative side of the developing bias when the negative charging toner is used and to the positive side of the developing bias when the positive charging toner is used. To be done.

A transfer bias power source 134 having a polarity opposite to that of the photosensitive member 100 is connected to the transfer member 114.

Here, the photoconductor 100 and the toner carrier 10
The length of the contact portion 4 in the rotation direction, that is, the so-called developing nip width, is preferably 0.2 mm or more and 8.0 mm or less from the viewpoint of image density and mechanical stress on the toner.

The toner coating amount is controlled by the developing blade 143, which is in contact with the toner carrier 104 via the toner layer.

The toner coat amount on the toner carrier is 0.
It is preferably 1 mg / cm ² or more and 1.5 mg / cm ² or less.
More preferably 0.2 mg / cm ² or more and 0.9 mg / c
m ² or less. If the amount is less than 0.1 mg / cm ^2, it is difficult to obtain a sufficient image density, and if the amount is more than 1.5 mg / cm ^2, it becomes difficult to uniformly triboelectrically charge all the individual toner particles, which is a cause of deterioration of fog suppression. Becomes

In FIG. 2, the primary charging member 117 uniformly charges the photoconductor 100 rotating in the arrow direction.

The primary charging member used here is a conductive core layer 117b having a central core bar 117b and an outer periphery thereof.
and a is a charging roller having a basic configuration. The charging roller 117 is brought into contact with the entire surface of the photoconductor with a pressing force, and is driven to rotate as the photoconductor 100 rotates.

After the primary charging step, an exposure 123 from the light emitting element 121 forms an electrostatic latent image on the photoconductor 100 according to the information signal. The electrostatic latent image on the photoconductor 100 is visualized by the toner at the position where it is in contact with the toner carrier 104.

Next, the visible image is transferred onto the transfer target 127 by the transfer member 114, and the transfer toner 129 is transferred to the transfer target 127 together with the heating roller 128 and the pressure roller 1.
It is passed through between 26 and fixed to obtain a permanent image. In addition,
As the heating / pressurizing fixing means, in addition to the heating roller system which basically has a heating roller having a heating element such as a halogen heater shown here and an elastic pressing roller pressed against this with a pressing force, a film A method of heating and fixing with a heater via the is also used.

On the other hand, the untransferred residual toner 124 that has not been transferred and remains on the photosensitive member 100 is cleaned by the cleaning blade 120.
It is cleaned by the cleaning means 120 having a and collected in the cleaning container.

The toner and image forming method of the present invention can also be used in full color image formation. The image forming method shown in FIG. 3 will be described as an example of the full-color image forming method.

The full-color image forming method is not limited to the structure shown in FIG. 3, but a full-color image forming method in which color toners are directly superposed on a transfer material and multiple development is performed, particularly in-line form A full-color image forming method in which color developing devices are arranged to perform sequential development can also be preferably used in the present invention.

In the apparatus system shown in FIG. 3, the developing devices 4-1, 4-2, 4-3, and 4-4 respectively include a developer having a cyan toner, a developer having a magenta toner, and
A developer having a yellow toner and a developer having a black toner are introduced.

First, the electrostatic latent image on the photoconductor 1 is developed by the developing device 4-1.

The visualized toner image on the photosensitive member is transferred to the intermediate transfer member 5 arranged in contact with the lower surface of the photosensitive member 1 by a primary transfer voltage (for example, ± 0.1 ±±). 5 KV) for primary transfer. At this time, the detachable cleaning means 10 is detached from the intermediate transfer body 5 so that the toner image visualized by the developing device 4-1 is held on the intermediate transfer body 5.

Then, in the same manner, the developing units 4-2, 4-
3 and 4-4 are sequentially developed and the toner images of the first color, the second color, the third color and the fourth color are superposed on the intermediate transfer body 5, and these toner images are formed on the outer surface of the intermediate transfer body 5. Transfer material 6 placed
Transfer voltage between the transfer roller 7 and the transfer roller (for example, ±
0.5 to ± 10 kV) and is collectively transferred onto the transfer material 6. After the toner image is transferred onto the transfer material 6, the surface of the intermediate transfer body 5 is cleaned by the detachable cleaning means 10.

Subsequently, the toner image on the transfer material 6 is fixed by the heat and pressure fixing means H to obtain a permanent image.

FIG. 4 shows an example of the developing means of the present invention.

Development can be carried out using a one-component system contact developing type developing means equipped with the developing device 31. Specifically, while applying a direct current or an alternating electric field to the toner carrier 37 by the power source 36, the toner 3 is supplied from the coating roller 32 and the coating amount is regulated by the developing blade 33.
Development is carried out in a state where 4 is in contact with the photoconductor 35. When using an alternating electric field, triangular wave, rectangular wave, sine wave, D
It is also possible to select and use a waveform in which the duty ratio is changed or a waveform in which the alternation is regularly turned off, but in the present invention, a DC electric field with a small voltage load on the photoconductor is preferably used,
The applied voltage is set to an appropriate value between the dark potential (potential immediately after the charging step) and the bright potential (potential after the exposure step) on the photoconductor.

[0198]

EXAMPLES The present invention will be described in more detail by showing examples below, but the present invention is not limited to these examples. Parts mean parts by weight.

The method of manufacturing the charging roller will be described below.

(Production Example 1 of charging roller) EPDM10
40 parts of conductive carbon black, 50 parts of paraffin oil, and a proper amount of a foaming agent, a cross-linking agent, and other compounding agents were added to 0 part and kneaded to prepare a conductive compound 1.
Next, the compound was vulcanized and molded on a stainless steel core bar having a diameter of 6 mm, and then the outer diameter was polished to prepare an elastic layer 1 which was a foam having a thickness of 3 mm.

Next, 14.5 parts of conductive carbon black was mixed with 10 parts of an ether type thermoplastic urethane elastomer (JIS-A hardness; 63.2) and melt-kneaded at 180 ° C. for 10 minutes using a pressure kneader. . After further cooling, it was pulverized with a pulverizer and then pelletized using a single-screw extruder.

Using an extruder, the pellets having an inner diameter of 1
A seamless tube having a thickness of 0.5 [mm] and a thickness of 500 [μm] was obtained. Hereinafter, this tube is referred to as tube A.

Separately from this, a thermoplastic elastomer in which a polystyrene molecular chain is bonded to one end of an ethylene butylene rubber molecular chain and an olefin crystal is bonded to the other end by a covalent bond (J
IS-A hardness: 63.2) 100 parts of 100 parts of conductive carbon black is mixed, and a pressure kneader is used to obtain 200 ° C.
And melt-kneaded for 10 minutes. After further cooling, it was pulverized with a pulverizer and then pelletized using a single-screw extruder. Furthermore, using an extruder, these pellets have an inner diameter of 11.5 [m
m] and a wall thickness of 200 [μm] were obtained. This tube is hereinafter referred to as tube B.

Subsequently, while air was blown into the tube A to expand the outer diameter, the elastic layer 1 was inserted to coat the tube, and then the tube B was coated on the outside in the same manner to obtain the charging roller 1. It was

The characteristics of the charging roller 1 thus obtained are as follows.

Surface hardness: 63.2 degrees (JIS-A) 10-point average surface roughness (Rz); 1.5 μm

The surface hardness (JIS-A) is JIS-K6.
It is a value measured by a spring type hardness tester A type according to the method specified in No. 301.

(Production Example 2 of charging roller) In Production Example 1, the surface hardness was 63.2 degrees and the 10-point average surface roughness (Rz) was obtained in the same manner as in Production Example 1 except that the step of roughening the elastic layer was used. A charging roller 2 having a size of 4.9 μm was obtained.

(Production Example 3 of charging roller) In Production Example 1, the surface hardness was 63.2 degrees, and the 10-point average surface roughness was obtained in the same manner as in Production Example 1, except that the step of polishing the elastic layer was rougher than that in Production Example 2. A charging roller 3 having a (Rz) of 6.5 μm was obtained.

(Production Example 4 of charging roller) In Production Example 1, the JIS of the thermoplastic elastomer used for the tube A is used.
-A hardness is 35.6 degrees, and JIS-A hardness of the thermoplastic elastomer used for the tube B is 35.6 degrees. ) A charging roller 4 having a size of 1.5 μm was obtained.

(Production Example 5 of charging roller) In Production Example 1, JIS of thermoplastic elastomer used for the tube A is used.
-A hardness is 85.2 degrees and the thermoplastic elastomer used for the tube B has JIS-A hardness of 85.2 degrees in the same manner, but the surface hardness is 85.2 degrees and the surface roughness of 10 points average (Rz ) A charging roller 5 having a thickness of 1.5 μm was obtained.

(Production Example 6 of charging roller) In Production Example 1, the JIS of the thermoplastic elastomer used for the tube A is used.
-A hardness is 25.7 degrees and the thermoplastic elastomer used for the tube B has JIS-A hardness of 25.7 degrees in the same manner, but the surface hardness is 25.7 degrees and the surface roughness of 10 points average (Rz ) A charging roller 6 having a thickness of 1.5 μm was obtained.

(Production Example 7 of charging roller) In Production Example 1, the JIS of the thermoplastic elastomer used for the tube A is used.
-A hardness is 95.3 degrees, and JIS-A hardness of the thermoplastic elastomer used for the tube B is 95.3 degrees in the same manner except that the surface hardness is 95.3 degrees and the surface roughness of 10 points average (Rz ) A charging roller 7 having a thickness of 1.5 μm was obtained.

Specific examples of the hydrotalcite compounds used in the examples are shown in Table 1 below.

[0215]

[Table 1]

The method for producing the toner will be described below.

(Toner Production Example 1) The toner used in the present invention was prepared as follows. In a two-liter four-necked flask equipped with a high-speed stirring device TK-Homomixer, 910 parts of ion-exchanged water, 2 parts of polyvinyl alcohol, and 1 part of sodium dodecyl sulfate were added to adjust the rotation speed to 10,000 rotations / minute, It was heated to 60 ° C. to obtain a dispersant system.

On the other hand, the dispersoid system was: styrene monomer 60 parts 2-ethylhexyl acrylate monomer 40 parts grafted carbon black pigment (carbon content 50%) 10 parts di-alkyl salicylic acid aluminum complex compound 1 part saturated Polyester resin 10 parts (polycondensation product of propylene oxide-modified bisphenol A and terephthalic acid) After the above mixture was dispersed for 3 hours using a media type disperser, a low softening point substance (ester wax half-value width 4 ° C., DSC peak 65) 25 ° C.) was added, the internal temperature was raised to 60 ° C., and the temperature was kept for 30 minutes. Then, the dispersion to which 3 parts of 2,2′-azobis (2,4-dimethylvaleronitrile), which is a polymerization initiator, was added was put into the above dispersion medium and granulated for 10 minutes while maintaining 10000 rpm. did. After that, the stirrer was changed from the high-speed stirrer to the propeller stirrer, and the polymerization was performed at 150 rpm for 12 hours. After the polymerization was completed, the slurry was cooled, washed with water and dried to obtain black particles.

100 parts of the obtained black particles were subjected to a hydrophobic treatment to obtain a fine silica powder (BET = 130 m ² /
g) and 1.5 parts, and hydrotalcite A described in Table 1
0.1 part was added, and Toner A uniformly adhered by Henschel mixer (Mitsui Miike Kakoki Co., Ltd.) was obtained.

The circle-equivalent number average diameter of the toner A is 6.3 μm.
m, average circularity by flow type particle image analyzer is 0.9
73, and the standard deviation of circularity was 0.033. Details are shown in Table 2.

(Production Examples 2 to 4 and 7 to 12 of Toner) The same procedure as in Production Example 1 of Toner above except that the kinds and amounts of the colorant, the aluminum complex compound of oxycarboxylic acid, and the wax component were changed. And polymer particles B to D and G to
After obtaining P, the toners B to D and G to P are changed while changing the types and addition amounts of the inorganic fine powder and the hydrotalcite compound.
Was prepared. Details are shown in Table 2.

(Production Example 5 of Toner) Polyester resin obtained by condensing propoxylated bisphenol with fumaric acid and trimellitic acid 100 parts-Phthalocyanine pigment 4 parts-Aluminum complex compound of di-alkylsalicylic acid 4 parts-Low Molecular weight polypropylene 4 parts The above raw materials are pre-mixed by a Henschel mixer, melt-kneaded by a twin-screw extrusion type kneader, cooled and roughly crushed to about 1 to 2 mm by a hammer mill, and then finely pulverized by an air jet method. Finely pulverized with a pulverizer. Further, the obtained finely pulverized product was classified and then spheroidized by mechanical impact to obtain a blue powder having a weight average particle diameter of 7.3 μm.

Production Example 1 with respect to 100 parts of the above-mentioned colored particles
1.0 parts of the hydrophobic silica used in Example 1 and 0.2 parts of hydrotalcite A described in Table 1 were used in a Henschel mixer FM10.
Toner E was obtained by externally adding B.

The toner E has a circle-equivalent number average diameter of 6.5 μm.
m, average circularity by flow type particle image analyzer is 0.9
62, and the standard deviation of circularity was 0.030. Details are shown in Table 2.

(Production Example 6 of Toner) Finely pulverized particles F were prepared in the same manner as in Production Example 5 of the toner described above, except that the kinds and addition amounts of the colorant, the aluminum complex compound of oxycarboxylic acid, and the wax component were changed. After the toner was obtained, the type and the addition amount of the inorganic fine powder and the hydrotalcite compound were changed to obtain an externally added toner F.

The circle-equivalent number average diameter of the toner F is 7.2 μm.
m, average circularity by flow type particle image analyzer is 0.9
45, the standard deviation of circularity was 0.037. Details are shown in Table 2.

(Production Examples 1 to 4 of Comparative Toner) Colorant,
Production Example 1 of the toner, except that the kind and addition amount of the metal complex compound of oxycarboxylic acid and the wax component were changed.
After obtaining the polymer particles M to P in the same manner as described above, the toners M to P were adjusted while changing the types and addition amounts of the inorganic fine powder and the hydrotalcite compound. Details are shown in Table 2.

[0228]

[Table 2]

<Example 1> The toner A of Production Example 1 was used in a high temperature and high humidity environment (30 ° C / 30 ° C) using a laser beam printer of A3 size having the configuration shown in FIG. 80%) and low temperature and low humidity environment (10 ° C / 15
%), A continuous durability test of 5000 images having an image area ratio of 5% was performed. On the 10th sheet and the 5000th sheet, a solid white image and a halftone image were output as samples to evaluate fog, image uniformity, and contamination of the charging roller.

The obtained output image is in a high temperature and high humidity environment (30
C./80%) and low temperature and low humidity environment (10.degree. C./15%), both fog and halftone image uniformity were very good. Further, when the charging roller was visually observed, no contamination was confirmed.

<Examples 2 to 14> Evaluations were made in the same manner as in Example 1 except that the combinations of the toners A to L and the charging rollers 1 to 5 were changed as shown in Table 3, and generally good results were obtained. Got

Table 3 shows the results of these evaluations.

Comparative Examples 1 to 6 Evaluations were made in the same manner as in Example 1 except that the comparative toners M to P and the charging rollers 6 and 7 were used.

As a result, the toner containing no hydrotalcite-type compound having a specific structure had poor charging stability, and the contamination of the charging roller was promoted, resulting in poor image quality. Further, even if a toner containing hydrotalcite of a specific structure is used, if the hardness of the charging roller is not appropriate, the contamination of the charging roller due to the free hydrotalcite is extremely unusable. Further, regarding the toner containing the specific hydrotalcite, even if an electrophotographic system using a charging roller having an appropriate hardness is used, the toner having a large DSC half width is fogged due to the physical properties of the release agent on the surface and the deteriorated surface. And the contamination of the parts is extremely bad.

The results of these evaluations are summarized in Table 3.

The evaluation items described in the above Examples and Comparative Examples and their evaluation criteria are shown below.

<Image Fog> REFL is measured for fogging.
The measurement was performed using an ECTOMER MODEL TC-6DS (manufactured by Tokyo Denshoku Co., Ltd.). The black / magenta toner image was measured using a green filter, the yellow toner image was measured using a blue filter, and the cyan toner image was measured using an amber filter. The reflectances of standard paper and solid white pattern samples were measured and calculated by the following formula. . The initial fog was evaluated by the 10-sheet sample, and the durable fog was evaluated by the 5000-sheet sample. Fog (reflectance;%) = (reflectance of standard paper;%)-(reflectance of sample;%) ◎; less than 0.05% ○: 0.05% or more and less than 1.0% △: 1.0 % And less than 3.0% x: exceeds 3.0%

<Halftone Image Uniformity> The image uniformity was evaluated by observing the obtained halftone image and the surface of the charging roller.

The evaluation was made visually by ⊚, ∘, Δ and ×. ⊚: The uniformity of the halftone image is good, and the surface of the charging roller is clean. ○: The uniformity of the halftone image is good, but slight contamination can be seen on the surface of the charging roller. Δ: Halftone image. Is slightly poor, and contaminants on the surface of the charging roller are clearly recognizable. ×: The uniformity of the halftone image is poor, density unevenness occurs during the charging roller cycle, and contaminants on the charging roller surface are very visible. Level attached to

[0240]

[Table 3]

[0241]

The toner of the present invention can prevent contamination such as sticking of residual developer on the charging member and the surface of the member to be charged in an image forming method equipped with a contact charging device, resulting in poor charging or charging. It is possible to prevent image defects due to unevenness from occurring.

Furthermore, the toner of the present invention has little environmental dependence and is excellent in charging stability, and can maintain a high-quality image even when a large number of copied images or printer images are output.

[Brief description of drawings]

FIG. 1 is a schematic view of a charging roller suitable for the present invention.

FIG. 2 is a schematic diagram of a one-component image forming apparatus suitable for the present invention.

FIG. 3 is a schematic diagram of a full-color image forming apparatus using an intermediate transfer member, which is suitable for the present invention.

FIG. 4 is a schematic explanatory view of a developing device suitable for the present invention.

[Explanation of symbols]

1 photoconductor 2 charging roller

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 15/02 101 G03G 9/08 384 F term (reference) 2H005 AA06 AA08 AB06 CA14 CB07 CB08 CB10 DA02 EA05 EA06 EA07 EA10 2H200 FA01 FA02 FA18 FA19 GA16 GA17 GA18 GA23 GA33 GA46 GA47 GA50 GA57 GB12 GB22 GB25 GB26 GB50 HA02 HA28 HB12 HB22 HB43 HB45 HB46 HB47 HB48 JA02 JA23 JA28 JB06 JB10 MACMA 02 MA23 MA04 MA20 MA03 MA04 MA02 MA03 MB05 MB06 MC01 MC02 MC06 MC16 NA02 NA06 NA09 NA13

Claims (44)

[Claims] 1. A charging roller having a conductive elastic layer, which comprises a charging step in which a charging member is brought into contact with the surface of a photosensitive member and a voltage is applied from the outside to charge the charging member, and the charging member is a charging roller having a conductive elastic layer. Surface hardness is 30 to 90 in JIS-A
A toner applied to an image forming method, the toner having at least a binder resin, a colorant, and a release agent, and a toner containing a hydrotalcite compound. Differential thermal analysis (DS
The half width at the endothermic peak of C) is 14 ° C. or less,
A toner in which the hydrotalcite compound is represented by the following general formula (1). [Chemical 1] (Wherein 0 <[X = (x1 + x2 + ... + xk)] ≦ 0.
5, Y = (y1 + y2 + ... + yj) = 1-X, and j
And k are integers of 2 or more, M1 ²⁺ , M2 2 ⁺ , ... And Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, A ^n-
Represents an n-valent anion, and m ≧ 0. ) 2. The toner according to claim 1, wherein the hydrotalcite compound is represented by the following general formula (2). [Chemical 2] (Wherein 0 <[X = (x1 + x2 + ... + xk)] ≦ 0.
5, Y = (y1 + y2 + ... + yj) = 1-X, and j
And k are integers of 2 or more, M2, M3, ... and Mj are Z
n, Ca, Ba, Ni, Sr, Cu, and different metals selected from the group consisting of Fe, L2, L3, ... And L
k is a different metal selected from the group consisting of B, Ga, Fe, Co and In, A ⁿ⁻ is an n-valent anion, and m ≧
It is 0. ) 3. The toner according to claim 1, wherein the hydrotalcite compound is subjected to a hydrophobic treatment with a surface treatment agent. 4. The toner contains a charge control agent, and
The mass X (mg / g) of the oxycarboxylic acid extracted from 0.1 g of the toner with a 0.1 mol / liter sodium hydroxide aqueous solution is X = 0.10 to 20.0 mg.
4. The toner according to claim 1, wherein the toner satisfies the condition of / g (based on the mass of the toner). 5. The toner according to claim 1, wherein the half-value width at the endothermic peak of the toner is 7 ° C. or less. 6. The toner according to claim 1, wherein an endothermic peak value in a DSC endothermic curve of the release agent is 50 ° C. to 120 ° C. 7. The toner according to claim 1, wherein an endothermic peak value in a DSC endothermic curve of the release agent is 60 ° C. to 100 ° C. 8. The weight average molecular weight (Mw) of the release agent is 3
The toner according to any one of claims 1 to 7, wherein the toner is from 00 to 1500. 9. The release agent has a weight average molecular weight (Mw) of 4
The toner according to any one of claims 1 to 7, which is 00 to 1250. 10. The toner according to claim 1, wherein the release agent has a penetration of 15 degrees or less. 11. The toner according to claim 1, wherein the release agent has a penetration of 8 degrees or less. 12. The toner according to claim 1, which is obtained by a polymerization method. 13. The toner according to claim 1, wherein the releasing agent is contained in the binder resin in an amount of 1 to 40 parts by mass per 100 parts by mass. 14. The toner according to claim 1, wherein the releasing agent is contained in the binder resin in an amount of 5 to 30 parts by mass per 100 parts by mass. 15. The average circularity in a number-based circle equivalent diameter-circularity scattergram measured by a flow type particle image measuring device of the toner is 0.950 to 0.999. 15. The toner according to any one of 1 to 14. 16. The toner according to claim 1, wherein the average circularity of the toner is 0.950 to 0.999, and the standard deviation of circularity is less than 0.040. . 17. The toner according to claim 1, wherein the toner has an average circularity of 0.950 to 0.995, and a standard deviation of circularity of 0.015 or more and less than 0.035.
7. The toner according to any one of 6. 18. The toner has an average circularity of 0.970 to 0.995 and a circularity standard deviation of 0.015 or more.
The toner according to any one of claims 1 to 17, which is less than 035. 19. The external additive contained in the toner is at least one kind of inorganic fine powder selected from titania, alumina, silica or a complex oxide thereof. 19. The toner according to any one of 18. 20. Si in the toner contained in the toner
X-ray fluorescence intensity ratio (Mg / Si) of Mg is 1.5
20. × 10 ^{−3 to} 100 × 10 ^−3, and the fluorescent X-ray intensity ratio (Al / Si) of Al is 1.0 × 10 ^{−2 to} 100 × 10 ^−2. The toner according to any one of 1. 21. The toner according to claim 1, wherein the 10-point average surface roughness Rz of the charging roller is 5 μm or less. 22. The toner according to claim 1, wherein the 10-point average surface roughness Rz of the charging roller is 3 μm or less. 23. An image forming method comprising a charging step in which a charging member is brought into contact with the surface of a photoreceptor and a voltage is applied from the outside to perform charging, wherein the charging member is a charging roller having a conductive elastic layer, The surface hardness of the charging roller is 30 to 90 degrees according to JIS-A, and the toner applied to this image forming method includes toner particles containing at least a binder resin, a colorant and a release agent, and hydrotal. A toner having a site compound, a half-value width at the endothermic peak of a differential thermal analysis (DSC) of the toner of 14 ° C. or less, and the hydrotalcite compound is a toner of the general formula (1) shown below. An image forming method characterized by the above. [Chemical 3] (Wherein 0 <[X = (x1 + x2 + ... + xk)] ≦ 0.
5, Y = (y1 + y2 + ... + yj) = 1-X, and j
And k are integers of 2 or more, M1 ²⁺ , M2 2 ⁺ , ... And Mj ²⁺
Are different divalent metal ions, L1 ³⁺ , L2 ³⁺ ,
... and Lk ³⁺ are different trivalent metal ions, A ^n-
Represents an n-valent anion, and m ≧ 0. ) 24. The toner according to claim 2, wherein the hydrotalcite compound is a toner represented by the following general formula (2).
The image forming method according to item 3. [Chemical 4] (Wherein 0 <[X = (x1 + x2 + ... + xk)] ≦ 0.
5, Y = (y1 + y2 + ... + yj) = 1-X, and j
And k are integers of 2 or more, M2, M3, ... and Mj are Z
n, Ca, Ba, Ni, Sr, Cu, and different metals selected from the group consisting of Fe, L2, L3, ... And L
k is a different metal selected from the group consisting of B, Ga, Fe, Co and In, A ⁿ⁻ is an n-valent anion, and m ≧
It is 0. ) 25. The image forming method according to claim 23, wherein the hydrotalcite compound is subjected to a hydrophobic treatment with a surface treating agent. 26. The toner contains a charge control agent, and the mass X (mg / g) of oxycarboxylic acid extracted from 1 g of the toner with a 0.1 mol / L sodium hydroxide aqueous solution is X. = 0.10 to 20.0 mg /
26. The image forming method according to claim 23, wherein g (based on the mass of the toner) is satisfied. 27. The half value width of the endothermic peak of the toner is 7 ° C. or less.
The image forming method according to any one of 1. 28. The image forming method according to claim 23, wherein an endothermic peak value in a DSC endothermic curve of the release agent is 50 ° C. to 120 ° C. 29. The image forming method according to claim 23, wherein the endothermic peak value in the DSC endothermic curve of the release agent is 60 ° C. to 100 ° C. 30. The weight average molecular weight (Mw) of the release agent is 300 to 1500.
30. The image forming method according to any one of 29 to 29. 31. The release agent has a weight average molecular weight (Mw) of 400 to 1250.
30. The image forming method according to any one of 29 to 29. 32. The image forming method according to claim 23, wherein the penetration of the release agent is 15 degrees or less. 33. The image forming method according to claim 23, wherein the penetration of the release agent is 8 degrees or less. 34. The image forming method according to claim 23, wherein the toner is obtained by a polymerization method. 35. The image forming method according to claim 23, wherein the releasing agent is contained in the binder resin in an amount of 1 to 40 parts by mass per 100 parts by mass. 36. The image forming method according to claim 23, wherein the releasing agent is contained in the binder resin in an amount of 5 to 30 parts by mass per 100 parts by mass. 37. An average circularity in a number-based circle equivalent diameter-circularity scattergram measured by a flow type particle image measuring device of the toner is 0.950 to 0.999. 37. The image forming method according to any one of 23 to 36. 38. The image according to claim 23, wherein the toner has an average circularity of 0.950 to 0.999 and a circularity standard deviation of less than 0.040. Forming method. 39. The toner according to claim 23, wherein the toner has an average circularity of 0.950 to 0.995 and a standard deviation of circularity of 0.015 or more and less than 0.035. The image forming method described in 1 .. 40. The toner has an average circularity of 0.970 to 0.995 and a circularity standard deviation of 0.015 to 0.
It is less than 035, It is characterized by the above-mentioned 23-36.
The image forming method according to any one of 1. 41. The external additive contained in the toner is an inorganic fine powder of at least one selected from titania, alumina, silica, or a double oxide thereof. 40. The image forming method according to 40. 42. Si in the toner contained in the toner
X-ray fluorescence intensity ratio (Mg / Si) of Mg is 1.5
× 10 ^-3 ~100 × 10 ^-3 and, claims 23 to 41 fluorescent X-ray intensity ratio of Al (Al / Si) is characterized in that it is a 1.0 × 10 ^-2 ~100 × 10 ^-2 The image forming method according to any one of 1. 43. The image forming method according to claim 23, wherein the 10-point average surface roughness Rz of the charging roller is 5 μm or less. 44. The image forming method according to claim 23, wherein the 10-point average surface roughness Rz of the charging roller is 3 μm or less.