JP2007304622A - Toner for electrostatic image development - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toner for electrostatic image development which shows stable charge behavior and avoids toner scattering, fogging and variation of image density even in long-term use or in printing of many sheets of paper, and to provide a toner for electrostatic image development further having high safety to the environment by using a colorant containing no harmful substance. <P>SOLUTION: The toner for electrostatic image development in which the colorant is dispersed in a binder resin is characterized in that the colorant is a colorant containing C.I. Pigment black 12. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  INDUSTRIAL APPLICABILITY The present invention provides a wide range of electrostatic charge image developing apparatuses ranging from low speed to high speed, which can provide high quality images with little background contamination, and further for developing electrostatic images using colorants containing no harmful substances. It relates to toner.

Conventionally, carbon black and black iron oxide (magnetite) have been mainly used as black pigments used in toner for developing electrostatic images. Carbon black is generally a low-cost pigment with a fine powder particle size and excellent colorability. However, since carbon black is a bulky powder with a bulk density of 0.1 g / cm ³ , handling is difficult and workability is poor. Carbon black is also classified into Group 2B by the International Agency for Research on Cancer, and problems from the health and safety side have been pointed out.

On the other hand, black iron oxide (magnetite) powder is cohesive due to the magnetic properties of Fe ₃ O _4, and when mixed with other toner raw materials, uniform mixing is difficult. There is a drawback that heat resistance is inferior, such as changing to brown Fe ₂ O ₃ at about 150 ° C.

  By the way, as characteristics required for the black colorant used in the toner for developing an electrostatic image, in addition to colorability, safety, handling at the time of manufacture, and heat resistance, there are electrical characteristics affecting development characteristics. is there. Electrical characteristics are one of the important characteristics required for colorants. When the electrical characteristics are further subdivided and listed, the rising characteristics of charging, the characteristics of maintaining charging for a long period of time, the uniformity of charging (charge amount distribution), the environmental stability of charging, and the like can be mentioned. Various factors can be cited as factors affecting these electrical characteristics, such as dispersibility of the colorant, electrical resistance, and surface properties of the colorant. If the electrical properties of the colorant are poor, the charge amount of each toner particle becomes non-uniform and the charge amount distribution becomes wide. In addition, the ratio of reversely charged particles and weakly charged particles increases, and during the development, the toner scatters inside the machine and the fogging phenomenon that the toner adheres to the non-image portion of the printed matter occurs. Furthermore, the toner tends to be inferior in durability, in which image density, resolution, and the like fluctuate for a long period of time or in multiple copies.

  So far, various materials have been studied as solutions to solve the disadvantages of carbon black or black iron oxide (magnetite) and replace them. Among them, in JP-A-3-2276, particles obtained by coating the surface of magnetite particles with a titanium compound or a mixed powder of magnetite particle powder and titanium compound are heated and fired at a temperature of 700 ° C. or higher. A black particle powder or the like has been proposed, and a technique relating to a toner using the black particle powder has been disclosed. However, the purpose of the publication is to provide a black colorant that is safe and harmless, and excellent in workability and heat resistance, and does not consider the improvement of the electrical characteristics. Also, in Japanese Patent Laid-Open No. 2000-319021, a black particle powder in which a certain amount of titanium component is contained in magnetite particles and a toner using the same are proposed. No consideration is given to improving the electrical characteristics.

  As described above, in the prior art, a technique relating to a toner using a novel black colorant that solves the drawbacks of carbon black or black iron oxide (magnetite) and sufficiently satisfies the electrical characteristics of the toner is disclosed. Absent.

JP 2000-319021 A

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a toner for developing an electrostatic image using a colorant that does not contain a harmful substance. Another object of the present invention is to provide a toner for developing an electrostatic image that exhibits stable charging behavior even after long-term use or printing of a large number of copies. It is another object of the present invention to provide a toner for developing an electrostatic charge image that is free from toner scattering and fog, has a sufficient image density, and can obtain a printed image with no fluctuation in image density.

  As a result of intensive studies to solve the above problems, the present inventors have found that C.I. I. The present inventors have found that the above problem can be solved by using a toner using Pigment Black 12, and have completed the present invention.

That is, the present invention is an electrostatic charge image developing toner in which a colorant is dispersed in a binder resin,
The colorant is C.I. I. Pigment Black 12, a coloring agent, and further, as a charge control agent, a metal salt or complex of an azo compound, a metal salt or metal complex of salicylic acid, a metal salt or metal complex of benzyl acid, or a formula 1,

(Formula 1)
(Wherein R ₁ Is a quaternary carbon, methine, or methylene, and may contain a heteroatom of N, S, O, or P, Y represents a cyclic structure connected by a saturated bond or an unsaturated bond, and R ₂ , R _Three Each independently has an alkyl group, alkenyl group, alkoxy group, aryl group or aryloxy group or aralkyl group or aralkyloxy group, halogen group, hydrogen, hydroxyl group or substituent which may have a substituent. Represents a good amino group, carboxyl group, carbonyl group, nitro group, nitroso group, sulfonyl group, cyano group, R _Four Represents hydrogen or an alkyl group, t is an integer of 0 to 1 to 12, m is an integer of 1 to 20, n is an integer of 0 to 1 to 20, k is an integer of 0 to 1 to 4, p is 0 to An integer of 1 to 4, q is an integer of 0 to 1 to 3, r is an integer of 1 to 20, and s is 0 or an integer of 1 to 20. )
And a toner for developing electrostatic images, comprising at least one selected from the compounds represented by formula (1).

  C. I. The toner for developing an electrostatic image of the present invention using a colorant containing Pigment Black 12 exhibits stable charging behavior even during long-term use or printing of a large number of copies. No printing can be performed.

  The present invention will be described in detail below. The colorant used in the present invention is C.I. I. It is a colorant classified as Pigment Black 12. The colorant is a composite oxide of titanium and iron, and is a composite oxide having a spinel structure represented by FeTiO 2 (Iron Titanium brown spinel). The colorant has a high blackness by adopting such a configuration. In addition, the toner using the colorant exhibits a stable charging behavior even when used for a long period of time or printing a large number of copies. Further, there is no toner scattering and fogging, and the image density is sufficient. The toner for developing an electrostatic charge image can obtain a printed image without fluctuation. Also, unlike carbon black, it does not contain harmful substances, so it is excellent in terms of safety and health.

  C. I. As a commercial item of the colorant classified into Pigment Black 12, for example, Battleship Gray No. 6, Chestnut Brown No. 180, Chocolate Brown No. 20, Russset Brown No. 20 8 (manufactured by Shepherd Color Company), Iruga Color 10358 (manufactured by Ciba Geigy) and the like. The above are black or dark colorants. When the toner of the present invention is used as a black toner, in particular, Battleship Gray No. 6, or Chocolate Brown No. It is preferable to use 20. Also, brown or light brown C.I. I. Examples of the colorant classified as Pigment Black 12 include “Autumn Brown No. 1”. 156, Golden Brown No. 19 (manufactured by Shepherd Color Company). When the toner of the present invention is a brown toner, these colorants are preferably used.

  The amount of the colorant used in the present invention is preferably in the range of 3 to 30 parts by weight, particularly preferably in the range of 5 to 15 parts by weight per 100 parts by weight of the toner. If it exceeds 30 parts by weight, the true specific gravity of the toner increases and toner scattering tends to occur.

  Moreover, although the said colorant is used in this invention, a well-known colorant can be used in order to adjust a hue. For example, as the black colorant, carbon black such as furnace black, channel black, acetylene black, thermal black, lamp black, etc. classified according to the production method, or C.I. I. Pigment Black 11 iron oxide pigment, aniline black, phthalocyanine cyanine black BX, and the like. The colorant used in the present invention is characterized by containing no harmful substances, and the object of the present invention is to provide a toner for developing an electrostatic image containing no harmful substances. Therefore, it is necessary to pay sufficient attention to the content of harmful substances and the amount used in combination with the black colorant used in the present invention.

  As the blue colorant, phthalocyanine C.I. I. Pigment Blue 15-3, Indanthrone C.I. I. Pigment Blue 60 and the like, red colorants include quinacridone C.I. I. Pigment Red 122, an azo-based C.I. I. Pigment Red 22, C.I. I. Pigment Red 48: 1, C.I. I. Pigment Red 48: 3, C.I. I. Pigment Red 57: 1 and the like, and azo-based C.I. I. Pigment Yellow 12, C.I. I. Pigment Yellow 13, C.I. I. Pigment Yellow 14, C.I. I. Pigment Yellow 17, C.I. I. Pigment Yellow 97, C.I. I. Pigment Yellow 155, an isoindolinone-based C.I. I. Pigment Yellow 110, a benzimidazolone-based C.I. I. Pigment Yellow 151, C.I. I. Pigment Yellow 154, C.I. I. Pigment Yellow 180 and the like.

In the present invention, a known charge control agent can be used as necessary. For example, as a negative charge control agent, trimethylethane dye, metal salt or complex of salicylic acid, metal salt or complex of benzyl acid, copper phthalocyanine, perylene, quinacridone, metal salt or complex of azo compound, calixarene type phenol condensation Products, cyclic polysaccharides, resins containing carboxyl groups and / or sulfonyl groups, and the like can be used.

Suitable negatively chargeable charge control agents that can be used in the present invention include metal salts or complexes of azo compounds, metal salts or complexes of salicylic acid, metal salts or complexes of benzylic acid, or compounds represented by the following formula 1. .

（式１）
（式中、Ｒ_１は４級炭素、メチン、メチレンであり、Ｎ、Ｓ、Ｏ、Ｐのヘテロ原子を含んでいてもよく、Ｙは飽和結合又は不飽和結合で結ばれた環状構造を表し、Ｒ_２、Ｒ_３は相互に独立してアルキル基、アルケニル基、アルコキシ基、置換基を有しても良いアリール基又はアリールオキシ基又はアラルキル基又はアラルキルオキシ基、ハロゲン基、水素、水酸基、置換基を有しても良いアミノ基、カルボキシル基、カルボニル基、ニトロ基、ニトロソ基、スルホニル基、シアノ基を表し、Ｒ_４は水素又はアルキル基を表し、ｔは０ないし１から１２の整数、ｍは１から２０の整数、ｎは０ないし１から２０の整数、ｋは０ないし１から４の整数、ｐは０ないし１から４の整数、ｑは０ないし１から３の整数、ｒは１から２０の整数、ｓは０又は１ないし２０の整数である。）

(Formula 1)
(Wherein R ₁ is a quaternary carbon, methine, or methylene, and may contain a heteroatom of N, S, O, or P, and Y represents a cyclic structure connected by a saturated bond or an unsaturated bond. , R ₂ and R ₃ are each independently an alkyl group, an alkenyl group, an alkoxy group, an aryl group which may have a substituent, an aryloxy group, an aralkyl group or an aralkyloxy group, a halogen group, hydrogen, a hydroxyl group, An amino group, a carboxyl group, a carbonyl group, a nitro group, a nitroso group, a sulfonyl group or a cyano group which may have a substituent, R ₄ represents hydrogen or an alkyl group, and t is an integer of 0 to 1 to 12 , M is an integer from 1 to 20, n is an integer from 0 to 1-20, k is an integer from 0 to 1 to 4, p is an integer from 0 to 1 to 4, q is an integer from 0 to 1 to 3, r Is an integer from 1 to 20, s 0 or 1 to an integer of 20.)

Specific examples of the compound represented by Formula 1 include the following compounds (1-1) to (1-3) .

Compound (1-1)

Compound (1-2)

Compound (1-3)

Moreover, the metal salt or complex of benzylic acid which can be used suitably by this invention is a compound represented by following formula 2 .

（式２）
（式中、Ｒ_１およびＲ_４は水素原子、アルキル基、置換又は非置換の芳香環（縮合環も含む）を示し、Ｒ_２およびＲ_３は置換又は非置換の芳香環（縮合環も含む）を示し、ＭはＢ、Ａｌ、Ｆｅ、Ｔｉ、Ｃｏ、Ｃｒから選ばれる１種の３価の金属を示し、Ｘ^＋はカチオンを示す）

(Formula 2)
(In the formula, R ₁ and R ₄ represent a hydrogen atom, an alkyl group, a substituted or unsubstituted aromatic ring (including a condensed ring), and R ₂ and R ₃ represent a substituted or unsubstituted aromatic ring (including a condensed ring). M represents one trivalent metal selected from B, Al, Fe, Ti, Co, and Cr, and X ⁺ represents a cation)

Specific examples of the compound of formula 2 include the following compound (2-1) and compound (2-2) .

Compound (2-1)

Compound (2-2)

Furthermore, examples of the metal salt or complex of an azo compound that can be suitably used in the present invention include the following compound (3-1) to compound (3-5) .

Compound (3-1)

Compound (3-2)

化合物（３−３）
カチオンはＮＨ_４ ^＋及びＨ^＋、Ｎａ^＋、Ｋ^＋又はこれらの混合イオンである。

Compound (3-3)
The cation is NH ₄ ⁺ and H ⁺ , Na ⁺ , K ⁺ or a mixed ion thereof.

化合物（３−４）
カチオンはＮＨ_４ ^＋及びＨ^＋、Ｎａ^＋、Ｋ^＋又はこれらの混合イオンである。

Compound (3-4)
The cation is NH ₄ ⁺ and H ⁺ , Na ⁺ , K ⁺ or a mixed ion thereof.

化合物（３−５）
カチオンはＮＨ_４ ^＋及びＨ^＋、Ｎａ^＋、Ｋ^＋又はこれらの混合イオンである。

Compound (3-5)
The cation is NH ₄ ⁺ and H ⁺ , Na ⁺ , K ⁺ or a mixed ion thereof.

  In the present invention, it is preferable to use one or more of the above charge control agents. In particular, among the above charge control agents, it is preferable to use a black charge control agent. Examples of the black negatively chargeable charge control agent include metal salts or complexes of the above azo compounds. By using these black charge control agents together with the black colorant used in the present invention, the toner for developing an electrostatic charge image of the present invention can be made a toner having a higher blackness. By using a black charge control agent, the amount of the black colorant used in the present invention can be reduced. As a result, the true specific gravity of the toner can be reduced, and toner scattering can be prevented. When a black charge control agent is used, the amount of the black colorant used in the present invention is preferably in the range of 3 to 12 parts by weight, particularly preferably in the range of 5 to 9 parts by weight per 100 parts by weight of the toner. . The true specific gravity of the electrostatic image developing toner of the present invention is preferably 1.50 or less, more preferably 0.70 to 1.45.

  The above charge control agents may be used alone or in combination, and good charging performance can be obtained by adding 0.3 to 15 parts by weight, preferably 0.5 to 5 parts by weight with respect to the binder resin. It is done.

  The binder resin used in the toner for developing an electrostatic charge image of the present invention can be used without particular limitation as long as it does not impair the object of the present invention. Specifically, a polystyrene-based resin, a styrene- (meth) acrylic acid ester copolymer resin, or a vinyl-based copolymer resin such as a styrene-conjugated diene copolymer resin, a polyester resin, an epoxy resin, A butyral resin, a xylene resin, a coumarone indene resin, a hybrid resin combining the above-mentioned resins, and the like can be mentioned. Of these, a vinyl-based copolymer resin, a polyester resin, and an epoxy resin are preferable. A polyester resin can be particularly preferably used because it has a good balance of offset and transparency.

The polyester resin suitably used in the present invention is
(A) A polybasic acid compound selected from polybasic acids and / or acid anhydrides and / or lower alkyl esters thereof having a valence of 2 or more (B) A polyhydric alcohol having a valence of 2 or more is dehydrated and condensed by a conventional method. obtain.

  Examples of the dibasic or higher polybasic acid and / or acid anhydride include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, Examples thereof include dicarboxylic acids such as citraconic acid, hexahydrophthalic anhydride, tetrahydrophthalic anhydride, cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, azelaic acid, and sebacic acid, or acid anhydrides thereof, or derivatives thereof. Examples of the tribasic or higher polybasic acid and / or acid anhydride include trimellitic acid, trimellitic anhydride, pyromellitic acid, pyromellitic anhydride, and the like. Furthermore, as these lower alkyl esters, an alkyl residue preferably has 1 to 6 carbon atoms, more preferably 1 to 4 carbon atoms. Such a lower alkyl ester can be obtained by esterifying the above-mentioned dibasic or higher polybasic acid or acid anhydride thereof with a lower alcohol. Among the above polybasic acids, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, maleic acid, maleic anhydride, fumaric acid and the like are particularly preferable.

Moreover, the following compounds are mentioned as a polyhydric alcohol more than bivalence. For example, as a divalent aliphatic alcohol,
(A) ethylene glycol, polyethylene glycol, propylene glycol, tripropylene glycol, butanediol, pentanediol, hexanediol, neopentyl glycol, cyclohexanedimethanol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-tetrahydrofuran Examples include copolymer diols.

Examples of the divalent aromatic diol include the following compound (b), which is an alkylene oxide adduct of bisphenol A.
(B) Polyoxyethylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -polyoxyethylene- (2.0) -2,2-bis (4- Hydroxyphenyl) propane, polyoxypropylene- (6) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane, poly Oxypropylene- (2.4) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (3.3) -2,2-bis (4-hydroxy) Eniru) propane and derivatives of these.

Furthermore, as a polyhydric alcohol more than trivalence,
(C) Sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropane Triol, 2-methyl-1,2,4-butanetriol, trimethylol ethane, trimethylol propane, 1,3,5-trimethylol benzene and other alcohols, or ethylene glycol diglycidyl ether, hydroquinone di Glycidyl ether, N, N-diglycidyl aniline, glycerin triglycidyl ether, trimethylol propane triglycidyl ether, trimethylol ethane triglycidyl ether, pentaerythritol tetraglycidyl ether, neopentyl glycol diglycol Zyl ether, bisphenol A type epoxy resin, bisphenol F type epoxy resin, cresol novolac type epoxy resin, phenol novolac type epoxy resin, polymer or copolymer of epoxy compound-containing vinyl compound, epoxidized resorcinol-acetone condensate, Examples include partially epoxidized polybutadiene, semi-dry or dry fatty acid ester epoxy compounds.

  The polyester resin used in the present invention includes a polybasic acid compound selected from a divalent polybasic acid and / or an acid anhydride and / or a lower alkyl ester thereof and a divalent aliphatic polyhydric alcohol as main components. Further, it is more preferable to use a tribasic or higher polybasic acid compound, or a polyester resin crosslinked or branched with a trihydric or higher polyhydric alcohol described in the component (c) as necessary. . In that case, when using the compound of said (b) as a polyhydric alcohol, it is preferable that it is 0-30 mol% in all the alcohol components, and it is more preferable that it is 0-10 mol%. Among these, it is particularly preferable not to use the compound (b) at all.

  The polyester resin used in the present invention can be obtained, for example, by performing a dehydration condensation reaction or a transesterification reaction using the above raw material components in the presence of a catalyst. The reaction temperature and reaction time at this time are not particularly limited, but are usually 150 to 300 ° C. and 2 to 24 hours. As a catalyst for performing the above reaction, for example, zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate, or the like can be appropriately used. The blending ratio (molar ratio) of the polybasic acid compound and the diol component is preferably 8/10 to 10/8, particularly preferably 9/10 to 10/9. In addition, when a divalent polybasic acid compound and a diol component are reacted, a linear polyester resin is obtained. Moreover, when a polybasic acid compound having a valence of 3 or more is reacted with a polyhydric alcohol or the like, a branched or networked polyester resin is obtained. The polyester resin thus obtained may be used alone, or may be used by blending a plurality of polyester resins so as to achieve a desired performance.

  When a polyester resin is used as the binder resin of the toner for developing an electrostatic charge image of the present invention, the most preferred embodiment is that the (b) compound is not used as the polyhydric alcohol component, and a divalent polybasic acid and / or acid is used. A linear polyester resin obtained by reacting a polybasic acid compound selected from an anhydride and / or a lower alkyl ester thereof with a divalent aliphatic alcohol, and the compound (b) is not used as a polyhydric alcohol component. When a polybasic acid compound selected from divalent polybasic acids and / or acid anhydrides and / or lower alkyl esters thereof is used in combination with a crosslinked polyester resin obtained by reacting a divalent aliphatic alcohol and an epoxy resin It is. A toner using such a resin as a binder resin has good fixing performance at low temperatures and excellent offset performance at high temperatures.

  The softening point of the binder resin used in the present invention is preferably in the range of 90 to 180 ° C, more preferably in the range of 95 to 160 ° C. If it is less than 90 ° C., offset at high temperature tends to occur, and if it exceeds 180 ° C., fixability at low temperature tends to deteriorate.

  The softening point of the resin in the present invention is defined by a T1 / 2 temperature measured using a flow tester CFT-500 manufactured by Shimadzu Corporation, which is a constant load extrusion type capillary rheometer. Measurement with a flow tester was performed with a piston cross-sectional area of 1 cm 2, a cylinder pressure of 0.98 MPa, a die hole diameter of 1 mm, a die length of 1 mm, a measurement start temperature of 50 ° C., a temperature increase rate of 6 ° C./min, and a sample weight of 1.5 g. .

  Further, the glass transition temperature of the binder resin is preferably 50 ° C. or higher, and particularly preferably 55 ° C. or higher. When the Tg is 50 ° C. or lower, the blocking phenomenon (thermal aggregation) is likely to occur when the toner is stored, transported, or exposed to a high temperature in the developing device of the machine. The glass transition temperature here is defined as the extrapolated glass transition start temperature obtained by measurement according to JIS K7121. For the measurement, DSC-60 manufactured by Shimadzu Corporation was used.

  The acid value is preferably 1 to 30 mgKOH / g, and more preferably 1 to 20 mgKOH / g. Moreover, it is preferable that a hydroxyl value is 10-100 mgKOH / g, and it is more preferable that it is 10-60 mgKOH / g. If the acid value and the hydroxyl value are in the above ranges, it is preferable in terms of improving the moisture resistance of the toner.

  The toner for electrostatic image development of the present invention includes various known release agents, for example, polyolefin waxes such as polypropylene wax, polyethylene wax, polyamide wax, Fischer-Tropsch wax, and / or modified polyolefin wax, or A wax containing a higher fatty acid ester compound and / or an aliphatic alcohol compound can be appropriately used as a release agent.

  Among waxes containing higher fatty acid ester compounds and / or aliphatic alcohol compounds, waxes derived from natural products such as carnauba wax, rice wax, scale insect wax, montan ester wax, and synthetic ester waxes are pentaerythritol. As the tetrabehenate ester and the alcoholic wax, a higher alcoholic wax obtained by oxidizing Fischer-Tropsch wax or the like is particularly preferable.

  The release agent is desirably selected according to the binder resin used in combination. When a release agent having poor dispersibility with respect to the binder resin is selected, the exposure of the release agent to the toner particle surface tends to increase, and the fluidity of the toner tends to decrease. Further, in the pulverization step in the toner manufacturing process, the release agent is easily detached, the amount of the release agent contained in the toner is reduced, and the fixing / offset performance is easily lowered. Further, in the process of developing the toner, the released release agent is liable to cause soiling and scattering, and the image quality is likely to deteriorate. When the dispersion with respect to the binder resin proceeds excessively or when the release agent is compatible with the resin, the fixing / offset performance is liable to deteriorate. For these reasons, it is preferable to select a release agent that is appropriately dispersed in the binder resin, and the particle size of the release agent dispersed in the binder resin is preferably in the range of 0.01 to 5 μm, A range of 3 μm is more preferable.

  A preferable combination of the binder resin and the release agent used in the present invention is a wax containing a higher fatty acid ester compound and / or an aliphatic alcohol compound as a release agent when a polyester resin or an epoxy resin is used. When a vinyl copolymer is used, it is a combination using a polyolefin wax and / or a modified polyolefin wax.

  The melting point (drop point, softening temperature) of the release agent is preferably 60 to 180 ° C, more preferably 65 to 170 ° C. If the melting point is too low, the toner tends to aggregate during storage and the fluidity of the toner tends to decrease. When the melting point is too high, it is difficult to melt in the image fixing step and it is difficult to exert a sufficient release effect.

  Also, the release agent adheres to charging members such as blades and carriers and may cause instability of charging performance and deterioration of image quality. The penetration at 25 ° C. is preferably 5 or less, more preferably 2 or less.

  Natural waxes, synthetic ester waxes, and alcohol-based waxes have an acid value of about 2 to 40 as a catalog value due to the structure or free acid, but these values should be lower for the same reason as for resins. desirable.

  The release agent may be used alone or in combination, and 0.1 to 15 parts by weight, preferably 1 to 5 parts by weight, with respect to the binder resin can provide good fixing offset performance. When the amount is less than 0.1 part by weight, the offset resistance is easily impaired, and when the amount is more than 15 parts by weight, the fluidity of the toner is likely to be deteriorated, and the toner charging property is easily adversely affected by fixing to the charging member. .

  The toner for developing an electrostatic charge image of the present invention can contain additives other than a binder resin, a release agent, a charge control agent, and a colorant. For example, cerium oxide, silicon carbide, etc. can be used as lubricants and abrasives such as metal soap and zinc stearate.

  The toner for developing an electrostatic charge image of the present invention can be obtained by a very general production method regardless of a specific production method. For example, the resin, the colorant, and the charge control agent can be obtained by melt-kneading at a melting point (softening point) or higher of the resin, pulverizing, and classifying. Specifically, for example, the components such as the resin, the colorant, the release agent, and the charge control agent are uniformly mixed in advance by a Henschel mixer or the like before melt-kneading. The mixing conditions are not particularly limited, but may be mixed in several stages. The colorant and the charge control agent used here may be previously subjected to a flushing treatment so as to be uniformly dispersed in the resin, or a master batch melt-kneaded with the resin at a high concentration may be used.

  The above mixture is mixed by a kneading means such as a two-roll, three-roll, pressure kneader, or twin screw extruder. At this time, the colorant and the like may be uniformly dispersed in the resin, and the melt kneading conditions are not particularly limited, but are usually preferably 80 to 180 ° C. for 30 seconds to 2 hours.

  If necessary, coarse pulverization is performed for the purpose of reducing the load and improving the pulverization efficiency in the fine pulverization step. The apparatus and conditions used for coarse pulverization are not particularly limited, but it is general to coarsely pulverize to a particle size of 3 mm mesh pass or less with a rotoplex or a pulverizer.

  Next, a method of finely pulverizing with a mechanical pulverizer such as a turbo mill or a kryptron, an air pulverizer such as a spiral jet mill, a counter jet mill, or an impingement plate jet mill and classifying with an air classifier or the like can be mentioned. The pulverization and classification devices and conditions may be selected and set so as to obtain a desired particle size, particle size distribution, and particle shape.

  Other methods for producing the toner for developing an electrostatic charge image of the present invention include emulsion polymerization, suspension polymerization, and transfer disclosed in JP-A-5-66600 and JP-A-8-62891. There are phase emulsification methods. The phase inversion emulsification method generates a discontinuous phase of Water in Oil by adding an aqueous medium (water or a liquid medium containing water as a main component) to a mixture composed of a binder resin, a colorant, and the like, and an organic solvent. Addition of water causes phase inversion into a discontinuous phase of Oil in Water, and addition of an aqueous medium forms a suspension in which the mixture floats as particles (droplets) in the aqueous medium And then removing the organic solvent to produce toner particles.

  The volume average particle diameter of the particles constituting the toner is not particularly limited, but is usually preferably adjusted to 5 to 15 μm.

  In the present invention, various additives (referred to as external additives) can be used for the surface modification of the toner such as improvement of toner fluidity and charging characteristics. Examples of the external additive that can be used in the present invention include inorganic fine powders such as silicon dioxide, titanium oxide, and alumina, those obtained by surface treatment with a hydrophobizing agent such as silicone oil, and resin fine powders. .

Among them, examples of materials that can be suitably used as an external additive for positively charged toner include hydrophobic silica obtained by surface treatment of silicon dioxide with various polyorganosiloxanes and silane coupling agents.
Specifically, there are those marketed under the following trade names.
AEROSIL; RA200HS, RA200H [Nippon Aerosil Co., Ltd.]
WACKER; H2050, HVK2150, HDK H30TA, H13TA, H05TA [Wacker Chemicals Co., Ltd.]
CABOSIL; TG820F [Cabot Specialty Chemicals, Inc.] and the like.

Further, the titanium oxide may be a hydrophilic grade or a hydrophobic grade that is surface-treated with octylsilane or the like. For example, there are those marketed under the following trade names.
Titanium oxide T805 [Degussa Co., Ltd.], Titanium oxide P25 [Nippon Aerosil Co., Ltd.], Titanium oxide JMT-150ANO [Taika Co., Ltd.], etc.
Examples of alumina include aluminum oxide C [Degussa Co., Ltd.].

  The particle size of these external additives is preferably 1/3 or less of the diameter of the toner, and particularly preferably 1/10 or less. These external additives may be used in combination of two or more of different average particle sizes. The proportion of silica used is usually 0.05 to 5% by weight, preferably 0.1 to 3% by weight, based on the toner.

  When the toner for developing an electrostatic charge image of the present invention is used in a two-component development system, a carrier as shown below can be used. Iron powder, magnetite, ferrite, etc., used in the usual two-component development system can be used as the carrier core agent. Among them, the true specific gravity is low, the resistance is high, the environment is stable, and it is easy to make a spherical shape. Is preferably used. The shape of the core agent can be used without any problem, such as a spherical shape or an indefinite shape. The average particle diameter is generally 10 to 500 μm, but 30 to 100 μm is preferable for printing a high resolution image.

  Examples of the coating resin for coating these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether polyvinyl ketone, vinyl chloride / vinyl acetate. Copolymers, styrene / acrylic copolymers, straight silicone resins composed of organosiloxane bonds or modified products thereof, fluororesins, (meth) acrylic resins, polyesters, polyurethanes, polycarbonates, phenol resins, amino resins, melamine resins, benzoguanamine resins Urea resin, amide resin, epoxy resin, acrylic polyol resin and the like can be used. Among these, silicone resin, fluororesin, and (meth) acrylic resin are particularly excellent in charging stability and coating strength, and can be used more suitably. That is, the resin-coated carrier used in the present invention is a resin-coated magnetic carrier in which ferrite or magnetite is used as a core agent and is coated with one or more kinds of resins selected from silicone resins, fluororesins, and (meth) acrylic resins. It is preferable.

  In addition, the non-magnetic one-component development method includes a contact-type non-magnetic one-component development method in which a developing sleeve carrying toner is brought into contact with a photosensitive drum having an electrostatic latent image for development, and a toner on the developing sleeve. There is a non-contact type developing method in which the toner is developed by flying on a photoreceptor, and the toner for developing an electrostatic charge image of the present invention can be suitably used for both.

  EXAMPLES Next, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited to a following example.

(Resin synthesis example)
A synthesis example of the binder resin used in preparing the toner is shown below. The molecular weight of the THF-soluble component obtained by filtering a solution obtained by putting the resin obtained in each synthesis example in tetrahydrofuran (THF) and allowing it to stand for 12 hours was measured. For analysis, gel permeation chromatography (GPC) method was used, and molecular weight was calculated from a calibration curve prepared with standard polystyrene.
GPC device: HLC-8120GPC manufactured by Tosoh Corporation
Column: Tosoh Co., Ltd. TSK Guardcolumn SuperH-H TSK-GEL SuperHM-M 3 linked
Concentration: 0.5% by weight
Flow rate: 1.0 ml / min
The THF-insoluble fraction was calculated from the residue on the filter paper after 1 g of the sample powder was taken on a cylindrical filter paper and refluxed with a Soxhlet extractor using THF as a solvent for 8 hours.
The acid value was measured according to JIS K6901, and Tg was measured according to JIS K7121.

(Resin 1)
Isophthalic acid: 116 parts by weight Terephthalic acid: 166 parts by weight Trimellitic anhydride: 38 parts by weight Diethylene glycol: 26 parts by weight Neopentyl glycol: 104 parts by weight Ethylene glycol: 50 parts by weight Tetrabutyl titanate: 2 .5 parts by weight The above raw materials were put into a glass 2-liter four-necked flask, a thermometer, a stirring rod and a nitrogen introduction tube were attached, and the reaction was carried out in an electric heating mantle heater at 240 ° C. for 10 hours under a normal pressure nitrogen stream. The pressure was reduced successively and the reaction was continued at 10 mmHg. The reaction was followed by a softening point according to ASTM E28-517, and the reaction was terminated when the softening point reached 148 ° C. The obtained polyester resin was a colorless solid and had an acid value of 4, Tg: 72 ° C., and softening point: 151 ° C.

(Resin 2)
-Styrene: 380 parts by weight-Butyl methacrylate: 120 parts by weight-Divinylbenzene: 10 parts by weight-Benzoyl peroxide: 5 parts by weight Thermometer, glass air flow introduction tube, stirring rod with vacuum-resistant seal device, and water-cooled Dimroth condenser Was added to 500 parts of xylene and all of the above monomers and initiator. Nitrogen gas was introduced from a glass airflow introduction tube to replace the inside of the reactor with an inert atmosphere, and then the contents were gradually heated by a mantle heater with a slider box to 75 ° C. The reaction was carried out while maintaining the temperature at 65 ° C. to 80 ° C. After 10 to 12 hours, the temperature was raised to 130 ° C. in order to complete the polymerization and the polymerization was completed. Next, the water-cooled condenser and the glass air flow introduction pipe were removed from the flask, and instead, a capillary for vacuum distillation and a Claisen fractionation pipe were attached. A thermometer and a water-cooled Liebig condenser were connected to the Claisen fraction tube, and the outlet of the condenser was connected to the eggplant-shaped flask via a suction adapter. The suction adapter and the vacuum pump were connected with a rubber tube for pressure reduction through a manometer and a trap, and preparation for vacuum distillation was completed. When the mantle heater was heated and the vacuum pump was operated with sufficient stirring of the contents to reduce the pressure to 20 mmHg, xylene or possibly unreacted monomer started to distill at a liquid temperature of 75 ° C. and a distillation temperature of 38 ° C. Finally, the pressure was reduced to 0.5 mmHg at a liquid temperature of 180 ° C. to completely remove the solvent. The obtained polymer (hereinafter referred to as polymer (a)) was poured into a stainless steel pan in a high-temperature molten state, crushed after cooling to room temperature.
The obtained polymer had a softening point of 145 ° C., Tg: 61 ° C., Mn: 8,000, and Mw: 21,000.

(Black colorant used in Examples)
-Colorant 1; Black colorant (Battleship Gray No. 6)
; Manufactured by Shepherd Color Company)
-Colorant 2; Black colorant (Chocolate Brown No. 20)
; Manufactured by Shepherd Color Company)

(Production of Comparative Colorant 1)
100 g of granular magnetite particles having an average diameter of 0.2 μm and a magnetization value of 85.0 emu / g are dispersed and mixed in an aqueous solution containing 0.26 mol of TiOSO 4, and then NaOH is added to the mixture. The mixture was neutralized, and a hydroxide of Ti was deposited on the particle surface at pH 8, followed by filtration and drying. Furthermore, after baking for 120 minutes at 750 ° C. under a N 2 gas flow, the mixture was pulverized to obtain a black particle powder (Comparative Colorant 1). The particle diameter of this black particle powder was 0.25 μm. Further, it was confirmed by X-ray diffraction that the particles were a mixed composition of Fe2TiO3 and Fe2O3-FeTiO3 solid solution.

Example 1
<Manufacture of toner>
-Resin 1 87 parts by weight-Colorant 1 8 parts by weight- Compound (3-3) 2 parts by weight-Refined carnauba wax No. 1 powder (manufactured by Hiroyuki Kato) 3 parts by weight The above raw materials were mixed using a Henschel mixer- The mixture was melt-kneaded with a twin-screw kneader, cooled and then finely pulverized with a jet mill, and classified to prepare a toner having an average particle size of 8.0 μm.

  Next, the toner of Example 1 was obtained by externally adding 1 part by weight of Nippon Aerosil silica “NAX50” and 1 part by weight of “RY-200” to 100 parts by weight of the toner.

Similarly, to prepare a toner composition shown in Table 1, Examples 2 to 5 by performing the external addition process as in Example 1 to obtain a toner of Comparative Example 1-2.

・モーガルＬ；カーボンブラック（キャボット製）
・カルナバ；カルナバワックス１号粉末（加藤洋行製）
・ＰＥＴＢ；ペンタエリスリトールのテトラベヘン酸エステル
・Ｅ−８４；ボントロンＥ−８４（サリチル酸の金属錯化合物「オリエント化学

・ Mogal L; carbon black (manufactured by Cabot)
-Carnauba; Carnauba wax No. 1 powder (manufactured by Kato Yoko)
PETB: pentaerythritol tetrabehenate ester E-84; Bontron E-84 (metal complex of salicylic acid "Orient Chemistry

(Print durability test)
Dedicated toner is removed from the cartridge of a commercially available non-magnetic one-component developing type printer ("IPSIO COLOR 2000" manufactured by Ricoh Co., Ltd.), and the washed cartridges are filled with the toners of the examples and comparative examples shown in Table 1. Continuous printing of 10,000 sheets was performed at an image density of 5%. The test was performed in an environment of 25 ° C. and 60%.

(Image density, background stain, charge amount)
The image density and background stain of the printed material were measured with a Macbeth densitometer RD-918. The background stain was determined by subtracting the white paper density before printing from the white background density after printing. When the difference was less than 0.01, it was evaluated as ◯, when it was less than 0.01 to less than 0.03, and when it was 0.03 or more, ×. Further, the charge amount of the printing toner was measured using a suction type small charge amount measuring device Mode 210HS (manufactured by Trek). The results are shown in Table 2 .

(Toner drop / toner splash)
After printing 10,000 sheets, the toner does not spill out from the developing sleeve mounted on the cartridge (toner dropping), scatter around the developing device (toner scattering) and do not contaminate the inside of the machine, ○ a small amount of toner dropping, or toner The state where scattering was recognized was judged as Δ, and the state where a large amount of toner dropped or toner scattering was found was judged as x. The results are shown in Table 2 .

  C. I. The toner for developing an electrostatic image of the present invention using a colorant containing Pigment Black 12 exhibits stable charging behavior even during long-term use or printing of a large number of copies. No printing can be performed.

Claims (3)

A toner for developing an electrostatic image in which a colorant is dispersed in a binder resin,
The colorant is C.I. I. Pigment Black 12, a coloring agent, and further, as a charge control agent, a metal salt or complex of an azo compound, a metal salt or metal complex of salicylic acid, a metal salt or metal complex of benzyl acid, or a formula 1,

(Formula 1)
(Wherein R ₁ Is a quaternary carbon, methine, or methylene, and may contain a heteroatom of N, S, O, or P, Y represents a cyclic structure connected by a saturated bond or an unsaturated bond, and R ₂ , R _Three Each independently has an alkyl group, alkenyl group, alkoxy group, aryl group or aryloxy group or aralkyl group or aralkyloxy group, halogen group, hydrogen, hydroxyl group or substituent which may have a substituent. Represents a good amino group, carboxyl group, carbonyl group, nitro group, nitroso group, sulfonyl group, cyano group, R _Four Represents hydrogen or an alkyl group, t is an integer of 0 to 1 to 12, m is an integer of 1 to 20, n is an integer of 0 to 1 to 20, k is an integer of 0 to 1 to 4, p is 0 to An integer of 1 to 4, q is an integer of 0 to 1 to 3, r is an integer of 1 to 20, and s is 0 or an integer of 1 to 20. )
A toner for developing an electrostatic image, comprising at least one selected from the compounds represented by formula (1): The binder resin is
(A) A polybasic acid compound selected from divalent polybasic acids and / or acid anhydrides and / or lower alkyl esters thereof (B) A single amount containing a divalent aliphatic polyhydric alcohol as a main constituent The toner for developing an electrostatic charge image according to claim 1, which is a polyester resin obtained by reacting a body. The electrostatic image developing toner according to claim 1, further comprising a higher fatty acid ester compound and / or an aliphatic alcohol compound as a release agent.