JPH07114270A - Charge donating member for electrostatic charge image developing - Google Patents

Abstract

PURPOSE:To provide such a charge donating member that performance does not deteriorate even for a long-term use, the amt. of triboelectric charges of an electrostatic charge image developing toner is improved by using the charge donating member, and sharp picture images with good image density, the reproducibility of fine lines and gradation with little fog can be obtd. CONSTITUTION:This charge donating member for electrostatic charge image developing has a compd. expressed by general formula on at least one part of its surface. In formula, R<1>, R<2>, R<3> and R<4> are hydrogen atoms, alkyl groups which may have substituents, cycloalkyl groups which may have substituents, or aralkyl groups which may have substituents, and A is an aromatuc rung residual group which may have substituents.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a material or member having an improved function for imparting an electric charge to a toner used for developing an electrostatic charge image in an electronic copying machine or the like.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, a uniform electrostatic charge is applied on a photoconductive insulating layer, and an electrostatic image is formed by irradiating the insulating layer with a light image. Then, the image is developed and visualized with a toner by the technique, a powder image is transferred to paper or the like as required, and then fixed on a copy paper surface by a fixing step.

As the toner applied to these, fine powders in which dyes and pigments are dispersed in natural or synthetic resins have been used. When a two-component developer is used, the toner is usually used as a mixture with carrier particles such as iron powder. In order to impart an electric charge to the toner, not only the triboelectric charging property of the resin in the toner component is utilized, but also a charge control agent such as a dye or a pigment that enhances the charging property is added. At present, nigrosine dyes, azine dyes, triphenylmethane dyes, quaternary ammonium salts or polymers having a quaternary ammonium side chain are known as charge control agents known in the art.

[0004]

In order to impart chargeability to the toner, these charge control agents must be exposed to the toner surface to some extent. Therefore, due to friction between the toner particles, collision with the carrier, and the like, the charge control agent falls off from the toner surface, resulting in carrier contamination and the like, resulting in poor chargeability.
Practical problems such as image density reduction, fine line reproducibility reduction, and fog increase occur. The charge control agents capable of imparting the charging property to the toner to the extent that they are practically sufficiently satisfied are very limited, and few are practically used.

The improvement of the charge imparting property to the toner is not achieved only by the charge control agent of the toner, but the carrier, the developing sleeve, the layer forming blade and the like which come into contact with the toner during the developing process are conveyed, regulated or friction members ( Hereinafter, these are collectively referred to as "charge-imparting material", and a material or member capable of contacting the toner prior to or during the developing step to impart the charge necessary for the development to the toner, or to supplement the charge. It is also tried to do. (JP-A-61-258
269). The method of positively applying the electric charge to the toner by using the electric charge-providing material can substantially improve the above-mentioned problems.

However, the charge-imparting material such as the carrier, the sleeve, and the layer-forming blade must be one that withstands friction with the toner and is highly durable, and in particular, the carrier can be used without being replaced for a long period of time. desired.

[0007]

Therefore, the inventors of the present invention have provided a charge-giving material for giving an appropriate charge to a toner, and have no deterioration in performance after long-term use, and fine line reproducibility and gradation. As a result of diligent studies to provide a charge-imparting material for obtaining an excellent image, a compound having a specific structure is used to impart a charge opposite to that of the prior art, that is, a positive charge. They have found what can be achieved and have reached the present invention. That is, the gist of the present invention is the general formula (1)

[0008]

[Chemical 2]

(Wherein R ¹ , R ² , R ³ and R ⁴ are each a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or Represents an aralkyl group which may have a substituent, A
Represents an aromatic ring residue which may have a substituent. ) The compound (hereinafter referred to as compound (1)) represented by the formula (1) is present in at least a part of the surface of the charge-imparting material for developing an electrostatic charge image. Hereinafter, the present invention will be described in detail.

In the above general formula (1), the substituent R ₁ ,
Specific examples of R ₂ , R ₃ and R ₄ are hydrogen atom; methyl group, ethyl group, n-propyl group, iso-propyl group, butyl group, pentyl group, hexyl group, heptyl group, octyl group, Alkyl groups such as nonyl group, decyl group, undecyl group, dodecyl group, tridecyl group, tetradecyl group, pentadecyl group, hexadecyl group, heptadecyl group, stearyl group, nonadecyl group; hydroxyl group-substituted alkyl group, halogen group-substituted alkyl group, alkoxyl Substituted alkyl group such as group-substituted alkyl group; cycloalkyl group such as cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group; alkyl group-substituted cycloalkyl group, hydroxyl group-substituted cycloalkyl group, halogen group-substituted cycloalkyl group, alkoxyl group Substituted cycloalkyl such as substituted cycloalkyl group Group; a benzyl group, aralkyl groups such as phenethyl group; an alkyl group substituted aralkyl group, a nitro group-substituted aralkyl group, and a substituted aralkyl group such as a halogen-substituted aralkyl group, and among them the number of carbon atoms 1
24, an alkyl group, a cyclohexyl group, a lower alkyl group-substituted cyclohexyl group, a halogen group-substituted cyclohexyl group, a benzyl group, a lower alkyl group-substituted benzyl group, a halogen group-substituted benzyl group, and a nitro group-substituted benzyl group are preferable. A methyl group, an ethyl group, a butyl group and an alkyl group having 6 to 20 carbon atoms are particularly preferable.

Specific examples of A include a phenylene group, a naphthylene group and an anthrylene group, with a phenylene group and a naphthylene group being particularly preferred. As the substituent that A may have, an alkyl group, particularly a lower alkyl group, a halogen group, a hydroxyl group, an amino group, or a lower alkyl group-substituted amino group is preferable, and a hydroxyl group is particularly preferable. Among the compounds (1), the compounds represented by the following structural formulas can be mentioned as specific examples of the compounds which are particularly suitable as those contained in the charge-imparting material for electrostatic image development of the present invention, but are not limited thereto. It is not something that will be done.

Exemplified Compounds ( Compounds represented by the following structural formulas are hereinafter referred to as Exemplified Compound (1), Exemplified Compound (2), ...).

(1) R ₁ = R ₂ = CH ₃ , R ₃ = R ₄ =
_{C 18 H 37, A- (SO} 3 -) 2 = 1,5- naphthalene disulfonate ion _{(2) R 1 = R 2} = CH 3, R 3 = R 4 = C 18 H 37, A
^{_{- (SO 3 -) 2 =}} m- benzenesulfonate ion _{(3) R 1 = R 2} = CH 3, R 3 = R 4 = C 16 H 33, A
^{_{- (SO 3 -) 2 =}} 1,5- naphthalene disulfonate ion _{(4) R 1 = R 2} = CH 3, R 3 = R 4 = C 16 H 33, A
^- (SO ₃ -) ₂ = toluene-3,4-disulfonic acid ion _{(5) R 1 = R 2} = CH 3, R 3 = R 4 = benzyl, A
^{_{- (SO 3 -) 2 =}} 1,5- naphthalene disulfonate ion

(6) R₁= R₂= CH₃, R₃= R_Four=
Benzyl, A- (SO₃ ^-)₂= 2-naphthol-6,
8-disulfonate ion (7) R₁= R₂= CH₃, R₃= C₈H₁₇, R_Four=
And A- (SO₃ ^-)₂= 1,5-naphthalenedis
Ruphonate ion (8) R₁= R₂= CH₃, R₃= C₈H₁₇, R_Four=
And A- (SO₃ ^-)₂= 1,6-naphthalenedis
Ruphonate ion (9) R₁= R₂= CH₃, R₃= C₁₄H₂₉, R_Four=
And A- (SO₃ ^-)₂= 1,5-naphthalenedis
Ruphonate ion (10) R₁= R₂= CH₃, R₃= C₁₆H₃₃, R_Four=
Benzyl, A- (SO₃ ^-)₂= 1,5-naphthalene
Sulfonate ion

(11) R₁= R₂= CH₃, R₃= C₁₈
H₃₇, R_Four= Benzyl, A- (SO₃ ^-)₂= 1,5-
Naphthalene disulfonate ion (12) R₁= R₂= CH₃, R₃= C₁₈H₃₇, R_Four=
Benzyl, A- (SO₃ ^-)₂= 2,6-naphthalene
Sulfonate ion (13) R₁= R₂= R₃= C_FourH₉, R_Four= P-meth
Lubenzyl, A- (SO ₃ ^-)₂= 1,5-naphthalene
Disulfonate ion (14) R₁= R₂= R₃= C_FourH₉, R_Four= P-meth
Lubenzyl, A- (SO ₃ ^-)₂= 3,6-naphthalene
Disulfonate ion (15) R₁= R₂= R₃= C_FourH₉, R_Four= P-black
Lubenzyl, A- (SO ₃ ^-)₂= 1,5-naphthalene
Disulfonate ion

(16) R₁= R₂= R₃= C_FourH₉, R
_Four= P-chlorobenzyl, A- (SO ₃ ^-)₂= 1-na
Futol-3,6-disulfonate ion (17) R₁= R₂= CH₃, R₃= Cyclohexyl,
R_Four= Benzyl, A- (SO₃ ^-)₂= 1,5-naphtha
Range sulfonate ion (18) R₁= R₂= CH₃, R₃= Cyclohexyl,
R_Four= Benzyl, A- (SO₃ ^-)₂= 3-amino-
1,5-Naphthalenedisulfonate ion (19) R₁= R₂= CH₃, R₃= Cyclohexyl,
R_Four= P-chlorobenzyl, A- (SO₃ ^-)₂= 1,
5-Naphthalenedisulfonate ion (20) R₁= R₂= CH₃, R₃= Cyclohexyl,
R_Four= P-chlorobenzyl, A- (SO₃ ^-)₂= 1,
8-dihydroxynaphthalene-3,6-disulfonic acid
on

(21) R₁= R₂= R₃= C₂H₇, R
_Four= P-nitrobenzyl, A- (SO ₃ ^-)₂= 1,5
-Naphthalenedisulfonate ion (22) R₁= R₂= R₃= C₂H₇, R_Four= P-nit
Robenzyl, A- (SO ₃ ^-)₂= 3-amino-2,7
-Naphthalenedisulfonate ion (23) R₁= R₂= R₃= C₆H₁₃, R_Four= Benji
Le, A- (SO₃ ^-)₂= 1,5-naphthalenedisulfo
Nitrate ion (24) R₁= R₂= R₃= C₆H₁₃, R_Four= P-meth
Lubenzyl, A- (SO ₃ ^-)₂= 1,5-naphthalene
Disulfonate ion (25) R₁= R₂= R₃= C₈H₁₇, R_Four= CH₃,
A- (SO₃ ^-)₂= 1,5-naphthalenedisulfonic acid
ion

(26) R ₁ = R ₂ = R ₃ = C ₈ H ₁₇ , R
₄ = ^{_{benzyl, A- (SO 3 -) 2}} = 1,5- naphthalene disulfonate ion _{(27) R 1 = R 2} = R 3 = C 10 H 21, R 4 = CH 3,
^{_{A- (SO 3 -) 2 =}} 1,5- naphthalene disulfonate ion _{(28) R 1 = R 2} = R 3 = C 12 H 25, R 4 = CH 3,
^{_{A- (SO 3 -) 2 =}} 1,5- naphthalene disulfonate ion _{(29) R 1 = H,} R 2 = R 3 = R 4 = C 8 H 17, A-
(SO ₃ ⁻ ) ₂ = 1,5-naphthalenedisulfonate ion (30) R ₁ = 2-chlorocyclohexane, R ₂ = R ₃
= CH _3, R ₄ = ^{_{benzyl, A- (SO 3 -) 2}} = 1,
5-naphthalene disulfonate ion

Other preferable specific examples are those described in Japanese Patent Application No. 2-402016, Japanese Patent Application No. 5-012617, Japanese Patent Application No. 4-333181, and Japanese Patent Application No. 4-338959, which are added to the toner. Some of them are also included. The compound (1) is synthesized by a known method and can be used in the present invention regardless of its production method. An example of the specific manufacturing method will be described below. The compound (1) is generally represented by, for example, the general formula (2)

[0020]

[Chemical 3]

(Wherein R ₁ , R ₂ , R ₃ and R ₄ have the same meaning in the above general formula (1), X represents halogen such as chlorine and bromine) The salt compound is represented by the general formula (3)

[0022]

[Chemical 4]

(Wherein A is as defined in the above general formula (1), Y is an alkali metal such as sodium or potassium) and the compound is heated in water or alcohol at about 60 ° C. It is obtained by reacting. The compound (1) generally has an average particle size of 10-0.01 μm, especially 2-
It is preferable to use the particles as particles of 0.1 μ for forming the charge imparting material.

The compound (1) is applied to the base material of the charge-imparting material by dipping, spraying, brush coating, etc., with a coating solution obtained by dissolving or dispersing it in a solvent or a dispersion medium, together with a binder resin if necessary. Alternatively, when the base material is in the form of carrier particles, it may be soaked with the above coating solution, mixed and dried, or a method such as coating a direct mixture of the base material and the compound (1) with a fluidized bed. If the coating layer of the compound (1) is formed on the base material, the charge imparting material of the present invention can be obtained. Alternatively, the binder resin and the compound (1) may be directly melted and kneaded and extrusion-laminated on the base material to obtain a charge-giving material having a coating layer containing the compound (1). Further, the compound (1) may be contained in a moldable resin, and the compound (1) may be molded into the shape of carrier particles, a developing sleeve or a layer forming blade to be used as a charge imparting material.

As the binder resin or the molding resin component, various known ones can be used. For example, there are styrene resins, styrene acrylic copolymer resins, polyester resins, epoxy resins and mixed resins thereof, and those having an amino group in their alkyl side chains. After coating or molding, these resins may have a crosslinked structure, if necessary, to improve the durability of the surface layer of the charge-imparting material.

When the binder resin or the molding resin is used, the content of the compound (1) is preferably 0.5-200 parts, more preferably 2-100 parts, relative to 100 parts of the resin. The base material of the charge imparting material in the form of a developing sleeve or a layer-forming blade is generally a developing sleeve or a layer-forming blade such as a metal or alloy such as iron, aluminum, stainless steel or nickel, a non-metallic compound such as ceramics or plastics. What can be used as is can be used.

All known carriers can be used as the base material of the carrier-type charge-imparting material. Metals or alloys such as iron, nickel, aluminum and copper, or powders of metal compounds containing metal oxides. Alternatively, particles, or ceramic powder or particles of glass, SiC, BaTiO ₂ , or the like is used. In addition, those whose surface is treated with a resin or the like, resin powder, or resin powder containing a magnetic material can be used. The average particle size is preferably about 10 to 200 μm.

When the base material is coated, the coating amount must be appropriately controlled, but the compound (1) is 0.01
-10 mg / cm ² is preferable, and in particular 0.1-2 mg
/ Cm ² is particularly preferred. Further, through the series of cases described above, silica powder, ceramic powder such as aluminum oxide, cerium oxide, or silicon carbide may be used as a filler together with the compound (1). Further, a conductivity-imparting agent such as carbon black or tin oxide may be used for controlling the conductivity. Further, a release agent such as a fatty acid metal salt or vinylidene fluoride may be used to prevent the spent toner from accumulating on the developing sleeve or the carrier surface.

On the other hand, as the toner to be used in combination with the above-described charge-imparting material of the present invention, substantially all the toners similar to the conventional electrostatic image developing toners are effectively used. That is, the toner may be either non-magnetic or magnetic toner. More specifically, it is a colored fine particle in which a colorant is contained in the binder resin, and may contain magnetic powder. Further, these toners may contain a small amount of a charge-imparting substance, for example, a dye, a pigment, or a charge control agent, and a fluidizing agent such as colloidal silica, an abrasive such as cerium oxide or silicon carbide. A lubricant such as metal stearate may be contained. Further, a conductivity imparting agent such as carbon black or tin oxide may be contained.

[0030]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited to the following examples unless it exceeds the gist. In the following examples, "parts" simply means "parts by weight".

Example 1 100 g of the exemplified compound (1) was dissolved and dispersed in 1 l of methyl ethyl ketone (MEK), 1 kg of an iron powder carrier (particle size: 250-400 mesh) was dispersed therein, and the mixture was stirred in a ball mill for about 30 minutes. I spilled. This iron powder carrier mixed solution was dried to completely remove the solvent and then loosen the light agglomerates to obtain a carrier-like charge-imparting material according to the present invention. On the other hand, a toner was prepared by the following formulation.

[0032]

[Table 1] Styrene resin 100 parts (manufactured by Sanyo Chemical Co., Ltd., trade name SBM-600) Carbon black 10 parts (Mitsubishi Chemical Co., Ltd. # 44) Quaternary ammonium salt compound 2 parts (Orient Chemical Co., trade name Bontron) P-51)

The above materials were kneaded, then pulverized and classified to obtain a toner having an average particle diameter of 11 μm. This toner and the carrier-like charge imparting material were mixed at a weight ratio of 4: 100 to obtain a developer. When the triboelectric charge amount of the toner was measured by the blow-off method, it was +30 μC / g. Next, when this developer was actually copied with a commercially available copying machine using an organic photoconductor as a photoreceptor, the image density did not change from the initial stage up to 150,000 sheets, fine line reproducibility was good, gradation was also good, and there was no fog. A clear image was formed.

Comparative Example-1 Example- except that the exemplified compound (1) was not dissolved and dispersed.
A developer was prepared in the same manner as in 1. The amount of triboelectricity of toner is +
It was 20 μC / g. In addition, there was a change in the image density from the initial stage to 150,000 sheets, and the thin line reproducibility and gradation were also lacking. Fog also occurred.

Example-2 A developer was prepared in the same manner as in Example-1, except that the exemplified compound (3) was used instead of the exemplified compound (1). The triboelectric charge amount of the toner was +26 μC / g. In addition, a clear image was formed from the initial stage up to 80,000 sheets.

Example 3 Except that 100 g of Exemplified Compound (1) was dissolved and dispersed in 1 liter of MEK, 100 g of styrene-acrylic resin was dissolved in 1 liter of tetrahydrofuran (THF), and 20 g of Exemplified Compound (5) was mixed. A developer was prepared in the same manner as in Example-1. The toner triboelectric charge amount is +25 μC /
It was g. In addition, a clear image was formed from the initial stage up to 50,000 sheets.

Example-4 A developer was prepared in the same manner as in Example-3, except that the exemplified compound (9) was used instead of the exemplified compound (5). The triboelectric charge amount of the toner was +28 μC / g. In addition, a clear image was formed from the initial stage up to 60,000 sheets.

Example 5 A solution was prepared by dissolving 100 g of styrene-acrylic resin in 1 l of THF and mixing 10 g of Exemplified compound (11), and applying this solution to a developing sleeve by dipping to give a layer thickness of 5 μm. This sleeve was mounted on a commercially available copying machine (magnetic-component developing system), and an actual copying test was conducted. From the initial stage, clear images were formed on up to 5000 sheets.

Example 6 Instead of 10 g of the exemplified compound (11), the exemplified compound (1
A developer was prepared in the same manner as in Example-5 except that 30 g of 7) was used. A clear image was formed from the initial stage up to 4000 sheets.

Example 7 A solution was prepared by dissolving 100 g of styrene-acrylic resin in 1 l of THF and mixing 10 g of Exemplified compound (13), and spray-coating this solution on a metal blade to give a layer thickness of 2
It was set to 0 μm. This metal blade was mounted as a layer forming blade of a commercially available copying machine (magnetic-component type), and an actual copying test was conducted. A clear image was formed from the initial stage up to 6000 sheets.

Example 8 Instead of 10 g of the exemplified compound (13), the exemplified compound (2
A developer was prepared in the same manner as in Example-7 except that 50 g of 0) was used. From the initial stage, clear images were formed on up to 3000 sheets.

[0042]

The charge imparting material for developing an electrostatic charge image of the present invention does not deteriorate in performance even after long-term use, and by using the charge imparting material, the triboelectric charge of NATO for developing an electrostatic charge image is increased. It is possible to form a clear image with improved image density, fine line reproducibility, and gradation and less fog.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masako Takeuchi, 1000, Kamoshida-cho, Midori-ku, Yokohama-shi, Kanagawa Sanryo Kasei Co., Ltd.

Claims (4)

[Claims] 1. A compound represented by the general formula (1): (In the formula, R ¹ , R ² , R ³ and R ⁴ each have a hydrogen atom, an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, or a substituent. Which represents an optionally substituted aralkyl group, and A represents an aromatic ring residue which may have a substituent), and a charge imparting material for developing an electrostatic charge image, which comprises at least a part of the surface thereof. . 2. The charge-giving material for developing an electrostatic charge image according to claim 1, which is a carrier particle. 3. The charge-giving material for developing an electrostatic charge image according to claim 1, which is a developing sleeve. 4. The charge-giving material for developing an electrostatic charge image according to claim 1, which is a layer-forming blade.