JP3533905B2 - Charge control agent for electrostatic image development and toner using the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a charge control agent for developing an electrostatic charge image used in an electronic copying machine, etc., and a charge imparting material for imparting an electric charge to a toner using the same and a toner used for developing an electrostatic charge image. It is about.

[0002]

2. Description of the Related Art A developer used in an electronic copying machine or the like is temporarily adhered to an image bearing member such as a photoconductor on which an electrostatic charge image is formed in the developing process and then exposed in a transfer process. After being transferred from the body to the transfer paper, it is fixed on the copy paper surface in the fixing step. At that time, as a developer for developing the electrostatic charge image formed on the latent image holding surface, a two-component developer composed of a carrier and a toner and a one-component developer not requiring a carrier (magnetic toner,
Non-magnetic toner) is known.

One of the important characteristics required of toner is chargeability, and in particular, contact with the carrier or the vessel wall of the developing tank causes a positive or negative moderate level of charge,
Further, the charge level is required to be substantially stable over time even during continuous use or under adverse influence. The chargeability may be imparted to the toner by the resin or the colorant itself, but it is difficult to obtain sufficient chargeability. Therefore, as a substance (charge control agent) that imparts chargeability to the toner, a positive charge is conventionally used. It has been known to use a nigrosine-based dye, a quaternary ammonium salt, a negatively charged metal-containing monoazo dye, a salicylic acid metal complex, a copper phthalocyanine pigment, etc. in a toner.

[0004]

By the way, these conventional charge control agents have some problems in terms of chargeability imparting effect and other required properties of toner. One of them is the safety of the toner. Most of conventional charge control agents, particularly negative charge control agents, are dominated by the metal-containing dye type containing a metal such as chromium because of the high charge level applied. However,
As a component of a substance called toner, which is used in a place very close to the human body, metals such as chromium, which have doubts about safety,
It is preferred not to use. Particularly in recent years, the importance of such safety is increasing, and the toner does not contain metal such as chromium as much as possible, and the charge imparting effect is better than ever, and it is excellent in other toner required characteristics. Development of a charge control agent is desired.

The second problem of the toner is charge stability. Many conventional charge control agents have a high charge level but insufficient charge stability. For example, during continuous copying and continuous printing, the charge level changes over time, causing copy stains. Have the problem of doing. These problems tend to increase in recent years particularly with the demand for a copying machine or the like that can process a large number of sheets continuously and at high speed, and development of a charge control agent having more excellent charge stability is required. There is.

On the other hand, in addition to the above-mentioned charge control agent, the improvement of the chargeability of the toner can be achieved by transporting, regulating, or rubbing a carrier, a developing sleeve, a layer-forming blade, etc. which come into contact with the toner during the developing process. Including these, it is called a "charge-imparting material", and is a material or member capable of contacting with the toner prior to or during the developing process to impart the charge necessary for the development to the toner, or to supplement the charge. It is also attempted to do so. As the charge-imparting material, a material having a high durability against friction with the toner is required, and particularly, a material that can be used without changing the carrier for a long time is desirable.

[0007]

First, the inventors of the present invention have developed a high-quality electrostatic image for developing a high-quality electrostatic charge image which is excellent in charging stability and does not easily cause copy stains even if it does not contain a harmful metal such as chromium. The present invention has been earnestly studied to provide a toner, and a charge-providing material that does not deteriorate in performance after long-term use and can obtain an image with excellent fine line reproducibility and gradation.
It has been proposed to use a metal salt of the compound described in 3370 as a charge control agent (JP-A-9-21839). The inventors of the present invention have made repeated studies for the purpose of further improving performance, and
By using a compound in which a specific metal salt of the compound described in -218539 is partially hydrolyzed to control the metal content in a specific range as a charge control agent, it is found that these problems can be solved. The present invention has been reached.

That is, an object of the present invention is to provide a charge control agent which is excellent in charging stability and is also excellent in other required properties of toner, such as humidity resistance, light resistance and heat resistance. in use, even under adverse, print density stable moderate, it is to provide a toner pile high quality to occur in the copy dirt. Another object of the present invention is to provide a charge control agent having excellent safety. That is, the gist of the present invention resides in the general formula (I)

[0009]

[Chemical 3]

(In the formula, A and R each represent an aromatic ring residue which may have a substituent.
And -CONH-R are bonded to adjacent substitution positions on the aromatic ring residue A. ) Or general formula (II)

[0011]

[Chemical 4]

(In the formula, A ¹ , A ² , R ¹ and R ² each represent an aromatic ring residue which may have a substituent, and n represents a natural number. CONH-
R ¹ and -OH and -CONH-R ² are bonded to adjacent substitution positions on the aromatic ring residues A ¹ and A ² , respectively. ) A partial potassium salt of the compound represented by the formula (1), wherein the content of potassium is 0.001 to 0.5 mol per mol of the compound represented by the general formula (I) or the general formula (II). the electrostatic image developing charge control agent consisting of, and resides with the toner over with Re its <br/>.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in detail below. In the general formulas (I) and (II), A, A ¹ , A
² , R, R ¹ and R ² represent an aromatic ring residue, which may further have a substituent on the ring or a heterocycle. It may be a carbocyclic ring, a heterocyclic ring, or a carbocyclic and heterocyclic ring condensed.

Specific examples include benzene ring, naphthalene ring, anthracene ring, phenanthrene ring, carbazole ring, fluorene ring, fluorenone ring, dibenzofuran ring, dibenzothiophene ring and benzocarbazole ring, and preferably benzene ring, It is a naphthalene ring. More preferably, A, A ¹ and A ² are naphthalene rings, and R, R ¹ and R ² are benzene rings or naphthalene rings, respectively. Further, specific examples of the substituent which may be present on the aromatic ring include C _1-5 such as methyl group, ethyl group, propyl group, n-butyl group and tert-butyl group.
Alkyl group; haloalkyl group such as trifluoromethyl group; amino group; alkoxy group such as methoxy group, ethoxy group; halogen atom such as chlorine atom, bromine atom; nitro group;
A phenyl group, preferably a C _1-5 alkyl group,
A haloalkyl group and a halogen atom. More preferred are chlorine atom and trifluoromethyl group. The number of substitutions is preferably 1 to 5, and when there are plural substitutions, the substituents may be the same or different. In addition, A and R in the general formula (I), A ¹ , A ² , and R ¹ in the general formula (II).
And R ² may be the same or different.

In the general formula (II), the alkylene chain connecting A ¹ and A ² preferably has 1 to 5 carbon atoms, that is, n = 1 to 5, and more preferably 1 to 3 carbon atoms. The content of potassium is 0.001 to 0.5 mol, preferably 0.001 to 0.3 mol, and more preferably 1 mol to 1 mol of the compound represented by the general formula (I) or (II). The amount is preferably 0.001 to 0.1 mol (in the present invention, such a potassium content salt is referred to as a partial potassium salt). If the content of potassium exceeds the above range, the water resistance of the compound deteriorates, which is not preferable as a charge control agent. If the content of potassium is less than the above range, the charging characteristics of the compound will deteriorate. The compound represented by the general formula (I) can usually be easily synthesized by the following synthetic method. For example, the following general formulas (III) and (IV)

[0016]

[Chemical 5]

A compound represented by the formula (wherein A and R have the same definition as in formula (I)) is added with phosphorus trichloride in a solvent such as toluene or chlorobenzene.
Obtained by boiling and reacting. General formula (I)
Partial potassium salt having a potassium content of 0.
The compound of 001 to 0.5 mol can be synthesized by the following synthetic method. For example, the compound represented by the general formula (I) is dissolved by heating in a water / acetone solution of potassium hydroxide, and then water is added to the solution to crystallize the target compound. Further, a partial potassium salt of the compound represented by the general formula (II), in which the content of potassium is 0.001 to 0.5 mol, brass.
Somer (Brass.Sommer), Berichte (Be
r). No. 61,998 (1928), an alkali metal salt of a compound represented by the general formula (II) is synthesized, and then the treatment is carried out as shown in the following (a) or (b). That is, the general formulas (V) and (VI)

[0018]

[Chemical 6]

A compound represented by the formula (wherein A ¹ , A ² , R ¹ and R ² have the same definition as in the general formula (II)) is added to formaldehyde in an aqueous solution of KOH or NaOH, The sodium salt or potassium salt of the compound represented by the general formula (II) can be obtained by heating at 50 to 120 ° C. and reacting.

(A) In the case of sodium salt A solution prepared by dissolving the sodium salt of the compound represented by the general formula (II) in an organic solvent such as N-methylpyrrolidone, methanol, dimethylformamide, methyl ethyl ketone or the like, for example, potassium carbonate is used. , Potassium chloride or the like in an aqueous solution of potassium salt, or the sodium salt of the compound of the general formula (II) is suspended and washed with the above organic solvent and the above potassium salt.

In the case of (b) potassium salt, (i) a solution of a potassium salt of a compound represented by the general formula (II) in an organic solvent is added to water or is washed by suspending with an organic solvent and water. The same kind of organic solvent as described in (a) can be used. (Ii) The potassium salt of the compound represented by the general formula (II) is suspended and washed with hot water or the like. At this time, the same organic solvent as described in (a) may be added.

The amount of the organic solvent used in the above treatment is 100% of the sodium salt or potassium salt of the general formula (II).
10 to 500 parts by weight is preferable with respect to parts by weight. The amount of potassium salt such as potassium carbonate used is preferably 0.1 to 4 mol per 1 mol of the sodium salt of the general formula (II). The amount of water used is preferably 10 to 5000 parts by weight with respect to 100 parts by weight of the sodium salt or potassium salt of the general formula (II). The processing temperature is preferably 10 ° C to 100 ° C. A partial potassium salt having a desired potassium content can be obtained by selecting the post-treatment conditions of (a) or (b).

Of the compounds represented by the general formula (I) or (II), specific examples of the compounds suitable as the charge control agent for developing an electrostatic image of the present invention are shown in Tables 1 and 2 below.
Examples of the partial potassium salt of the compound represented by the formula (1), in which the content of potassium is 0.001 to 0.5 mol%, the charge control agent of the present invention is not limited thereto. .

[0024]

[Table 1]

[0025]

[Table 2]

(* 1. When an aromatic ring residue is represented, for example, a benzene ring residue and the like are simply described as benzene. * 2.-(CH ₂ ) _n- , --OH, and --CONH-- for A ¹ . The substitution positions of R ¹ are 1-position, 2-position, and 3-position, respectively. The same applies to A ^2. )

When the charge control agent of the present invention is used in a toner, at least a resin and a colorant are used in the toner.
The resin contained in the toner can be selected from a wide range including known resins. For example, polystyrene, chloropolystyrene, poly-α-methylstyrene, styrene-chlorostyrene copolymer, styrene-propylene copolymer, styrene-butadiene copolymer, styrene-vinyl chloride copolymer, styrene-vinyl acetate copolymer. , Styrene-maleic acid copolymer, styrene-acrylic acid ester copolymer (styrene-methyl acrylate copolymer, styrene-ethyl acrylate copolymer, styrene-butyl acrylate copolymer, styrene-octyl acrylate) Copolymer and styrene-phenyl acrylate copolymer, etc.), styrene-methacrylic acid ester copolymer (styrene-methyl methacrylate copolymer, styrene-ethyl methacrylate copolymer, styrene-butyl methacrylate copolymer) And styrene-phenyl methacrylate Copolymers, etc.), styrene-α-chloromethyl acrylate copolymers and styrene-acrylonitrile-acrylic ester copolymers and other styrene resins (styrene or styrene-substituted homopolymers or copolymers), Vinyl chloride resin, rosin-modified maleic acid resin, phenol resin,
Epoxy resin, saturated or unsaturated polyester resin,
There are low molecular weight polyethylene, low molecular weight polypropylene, ionomer resin, polyurethane resin, silicone resin, ketone resin, ethylene-ethyl acrylate copolymer, xylene resin, polyvinyl butyral resin and the like, but styrene is particularly preferable as the resin used in the present invention. -Acrylic acid ester copolymer, styrene-methacrylic acid ester copolymer, saturated or unsaturated polyester resin, epoxy resin and the like can be mentioned. Further, the above resins are not limited to being used alone, but may be used in combination of two or more kinds.

The colorant to be contained in the toner of the present invention can be selected from a wide range including known ones.
Carbon black, lamp black, iron black, ultramarine, nigrosine dye, aniline blue, phthalocyanine blue,
Examples thereof include phthalocyanine green, Hansa yellow, chrome yellow, rose bengal, triarylmethane dyes, monoazo dyes and disazo dyes and pigments.

The partial potassium salt of the compound represented by the above general formula (I) or (II) used as the charge control agent of the present invention is a pale yellow color, for example, blue, red, yellow, etc. used for full color development. The color toner may be contained in the color toner, and in this case, a colorant composed of a dye or pigment having a corresponding color tone is used. The content of the colorant is preferably 3 to 20 parts by weight with respect to 100 parts by weight of the resin.

The toner of the present invention has the general formula (I) or (I
As a method of incorporating a partial potassium salt of the compound represented by I) and other charge control agents, an internal addition method of adding and mixing with a resin in a toner, an external addition method of adding and mixing with a toner particle, etc. are possible. However, the internal addition method is more general and preferable. The content of the partial potassium salt of the compound represented by the general formula (I) or (II) in the toner is
0.1 to 20 parts by weight is preferable with respect to 0 parts by weight, more preferably 0.1 to 15 parts by weight, and further preferably 0.5.
~ 7 parts by weight. If the content of the partial potassium salt of the compound represented by the general formula (I) or (II) is too low, the effect of improving the charging property is not improved, and if it is excessive, the quality of the toner is deteriorated, which is not preferable.

In the toner of the present invention, apart from the partial potassium salt of the compound represented by the general formula (I) or (II),
Other charge control agents including known ones, that is, nigrosine dyes, quaternary ammonium salts, metal-containing complex compounds and the like may be contained. Further, in the toner of the present invention,
Other known additives such as solid electrolytes, polymer electrolytes, charge transfer complexes, conductors such as metal oxides such as tin oxide, semiconductors or ferroelectrics, magnetic substances, etc. are added to improve the electrical properties of the toner. Can be controlled.

In addition to the above, various plasticizers such as low molecular weight olefin polymers and auxiliary agents such as release agents may be added to the toner for the purpose of adjusting thermal characteristics and physical characteristics. Further, TiO ₂ , Al ₂ O ₃ and SiO are added to the toner particles.
_2. By adding fine powder such as Zn stearate and coating the surface of the toner particle with these, the fluidity and aggregation resistance of the toner can be improved. The charge control agent of the present invention is particularly preferably used for negatively chargeable toner.

The toner may be produced by kneading the above components with a kneader, cooling, pulverizing and classifying. Alternatively, an encapsulated toner or a polymerized toner may be adopted.
The toner of the present invention can be applied to a so-called one-component developer (magnetic toner or non-magnetic toner) such as a magnetite-containing toner, in addition to the two-component developer. The average particle size of the toner is preferably 5 to 20 μm.

As the carrier for forming the developer by mixing with the toner of the present invention, known magnetic substances such as iron powder type, ferrite type and magnetite type carriers, those having a resin coating on their surface or magnetic resin A carrier can be used. As the coating resin for the resin coating carrier, generally known styrene resins, acrylic resins, styrene-acrylic copolymer resins, silicone resins, modified silicone resins, fluorine resins, etc. can be used, but are not limited to these. It is not something that will be done. The average particle size of the carrier is not particularly limited, but one having an average particle size of 10 to 200 μm is preferable. It is preferable to use 5 to 100 parts by weight of these carriers with respect to 1 part by weight of the toner.

Next, the case where the charge control agent of the present invention is used as a charge imparting material will be described. The charge-imparting material is a carrier having at least a partial potassium salt of the compound represented by the general formula (I) or (II) on at least a part of its surface, a developing sleeve, a layer-forming blade, and other friction members. A coating solution obtained by dissolving or dispersing the charge control agent of the present invention in a solvent or a dispersion medium together with a binder resin, if necessary, is applied to the base material of the charge imparting material by dipping, spraying, brush coating or the like. Alternatively, when the base material is in the form of particles like a carrier, the base material may be dipped and mixed in the above coating solution and dried, or a method such as coating a direct mixture with the base material by a fluidized bed. The charge-giving material of the present invention can be obtained by forming a coating layer containing the charge control agent on top. Alternatively, the charge-imparting material may be obtained by directly melt-kneading the binder resin and the charge control agent and extrusion-laminating on the base material. Further, the charge control agent may be contained in a moldable resin, and the charge control agent 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.

[0036]

EXAMPLES The present invention will be described in more detail below with reference to examples. In the following examples, "parts" simply means "parts by weight". Further, the exemplified compound No. Is the compound No. of Table-1 or Table-2. Corresponding to. For potassium analysis, fluorescent X-ray analysis (XRF)
Was used.

Synthesis Example 1 (Synthesis of Na Salt of Exemplified Compound 8) 2- [N- (p-chlorophenyl) carbamoyl] -3
-Hydroxynaphthalene (Exemplary Compound 1), 282 g
To 400 ml of methanol and sodium hydroxide 113.
It was dissolved in 4 g and 1440 ml of water and heated to 80 ° C.
To this, 66 g of 35% formaldehyde aqueous solution was added and reacted at 80 ° C. for 9 hours. The reaction solution was cooled to 50 ° C. and filtered to obtain yellow crystals. The crystals are dried to give 261 g of fine powder of sodium salt of Exemplified Compound 8.
Got The content of sodium is 1 of Exemplified Compound 8.
It was 0.98 mol per mol.

Synthesis Example 2 (Synthesis of K salt of Exemplified Compound 8) Similar to Synthesis Example 1 except that 70 g of potassium hydroxide and 600 ml of methanol were used in place of the sodium hydroxide used in Synthesis Example 1. When the reaction operation was carried out, 257 g of yellow fine powder was obtained. The content of potassium was 0.92 mol per mol of the exemplified compound 8, and the crystals were slightly water-soluble.

Synthesis Example 3 (Synthesis of Partial Potassium Salt of Exemplified Compound 8) A solution prepared by dissolving 120 g of the sodium salt obtained in Synthesis Example 1 in 167 ml of N-methylpyrrolidone was added to 27 g of potassium carbonate in 2.4 liters of water. It melt | dissolved and was added to the liquid heated at 60 degreeC over 1 hour. The obtained mixed solution is 60 ° C.
After heating for 1 hour and filtering, pale yellow crystals were obtained. The crystals were dried to obtain 110 g of fine powder.
The potassium content was 0.031 mol per mol of Exemplified Compound 8. Almost no sodium was detected.

Synthesis Example 4 (Synthesis of Partial Potassium Salt of Exemplified Compound 8) 120 g of the sodium salt obtained in Synthesis Example 1 was added to 1.2 liters of water in which 50 ml of N-methylpyrrolidone and 15 g of potassium carbonate were dissolved. . The mixture was heated at 80 ° C. for 3 hours, cooled to 60 ° C., filtered, and dried to obtain 112 g of a pale yellow fine powder. The content of potassium was 0.01 mol per mol of the exemplified compound 8.

Synthesis Example 5 (Synthesis of Partial Potassium Salt of Exemplified Compound 8) 120 g of the potassium salt of Exemplified Compound 8 obtained in Synthesis Example 2
Except that potassium carbonate is not used, Synthesis Example 3
The reaction operation was performed in the same manner as in, to obtain 105 g of a pale yellow fine powder. The content of potassium was 0.05 mol per mol of the exemplified compound 8.

Synthesis Example 6 (Synthesis of Partial Potassium Salt of Exemplified Compound 8) 120 g of potassium salt of Exemplified Compound 8 obtained in Synthesis Example 2
Was added to 1.2 liters of water, heated to 80 ° C., and suspended washed for 3 hours. 109g after filtering and drying
To obtain a pale yellow fine powder. The content of potassium was 0.11 mol per mol of the exemplified compound 8.

Synthesis Example 7 Exemplified compound 8 (compound containing no potassium) 10 g of the potassium salt of Exemplified compound 8 obtained in Synthetic Example 2 was added to N
-Dissolved in 15 ml of methylpyrrolidone, 2 g of 35% hydrochloric acid
Was added to 100 ml of water. After stirring at 60 ° C. for 1 hour, filtration and drying were performed to obtain 9.5 g of a pale yellow fine powder. The content of potassium was 0.0001 mol or less per 1 mol of Exemplified Compound 8. Examples 1-4 and Comparative Examples 1-3

[0044]

[Table 3]   100 parts of polyester resin   Carbon black (Mitsubishi Chemical MA-100) 4 parts   Partial potassium salt of Synthesis Example 3 3 parts

The above materials were blended, kneaded, pulverized and classified to obtain a black toner having an average particle diameter of 9.2 μm. This toner 1
0.3% by weight of hydrophobized silica was added to 00 parts to obtain a test toner. The test toner was put into a non-magnetic one-component developing tank (rubber roller, urethane blade), the roller was rotated a certain number of times, and then the charge amount of the toner on the roller was measured. The results are shown in Table-3. Other than using the partial potassium salts shown in Table-3,
A toner was prepared in the same manner as in Example 1 and the charge amount was measured.
The results are shown in Table-3.

[0046]

[Table 4]

As shown in the above table, in the case of Comparative Examples 1 and 2 which did not contain potassium or contained almost no potassium, the charge amount was extremely small, and the content of Comparative Example 3 was too large.
In the case of No. 3, the amount of charge was small and it was colored deep yellow. From this result, it is clear that the partial potassium salt of the present invention is excellent as a charge control agent. Example 5

[0048]

[Table 5]   100 parts of polyester resin   Phthalocyanine blue 4 parts   Partial potassium salt of Synthesis Example 3 6 parts

The above materials were blended and kneaded, pulverized and classified to obtain a cyan toner having an average particle diameter of 8.9 μm. This toner 1
0.8 weight% of hydrophobized silica was added to 00 parts to obtain a test toner. When this test toner was actually photographed with a full-color printer (for non-magnetic components), a clear image with less fog was obtained. Again 800
The image quality did not deteriorate even after 0 sheets were copied.

[0050]

The electrostatic charge image developing charge control agent of the present invention is
It is a high-quality charge control agent for developing an electrostatic charge image, which is excellent in safety, has a sufficient charge level and charge stability, and does not cause copy stains due to continuous copying.

─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Masako Takeuchi 1000 Kamoshida-cho, Aoba-ku, Yokohama-shi, Kanagawa Mitsubishi Chemical Corporation Yokohama Research Institute (56) Reference JP-A-9-218539 (JP, A) Flat 8-272146 (JP, A) JP 5-173370 (JP, A) JP 3-85548 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) G03G 9 / 08

Claims (2)

(57) [Claims] 1. A compound represented by the general formula (I): (In the formula, A and R each represent an aromatic ring residue which may have a substituent. —OH and —CONH in the formula
-R is bonded to adjacent substitution positions on the aromatic ring residue A. ) Or general formula (II) (In the formula, A ¹ , A ² , R ¹ and R ² each represent an aromatic ring residue which may have a substituent, and n represents a natural number. In the formula, —OH and —CONH—R ¹ and -O
H and -CONH-R ² are respectively bonded to Aitonaru substitution positions on the aromatic ring residue A ¹ and A ^2. ) Is a partial potassium salt of the compound represented by the formula 1, wherein the content of potassium is represented by the general formula (I) or the general formula (II).
A charge control agent for developing an electrostatic charge image, which comprises a compound in an amount of 0.001 to 0.5 mol per mol. 2. A toner for developing an electrostatic charge image, which comprises a resin, a colorant, and the charge control agent for developing an electrostatic charge image according to claim 1.