JP2003255602A - Negatively chargeable toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin having excellent stability of charge amount, excellent dispersibility of a colorant, no fogging, high print density, and excellent balance between low-temperature fixability and high-temperature storage property. To provide a negatively chargeable toner which is unlikely to cause color transfer or sticking to a sheet. SOLUTION: A polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof and / or a polyhydric alcohol (A2) containing a sulfonic acid group or a salt thereof,
A negatively chargeable toner comprising a binder resin composed of a polyester resin obtained by polycondensation of an alicyclic divalent carboxylic acid compound (B) and a colorant.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a negatively chargeable toner. More specifically, the present invention relates to a negatively chargeable toner having a clear color tone, stable charging, and excellent transferability regardless of the one-component system or the two-component system.

[0002]

2. Description of the Related Art In recent years, full-color electrophotographic apparatuses, particularly digitized full-color electrophotographic apparatuses, have been attracting attention, and are being widely spread on the market with the development of OA. The electrophotographic toner used in an electrophotographic apparatus (hereinafter, may be simply referred to as “toner”) is mainly prepared by adding a colorant, a charge control agent, etc. to a binder resin, kneading, and then pulverizing, Further classification, particles produced by a so-called pulverization method (pulverization method particles) or a mixture of a polymerizable monomer, a colorant, a charge control agent, etc. is polymerized by a method such as suspension polymerization, emulsion polymerization, dispersion polymerization, etc. Then, particles (polymerized particles) produced by causing them to associate with each other are mainly used. Also, depending on the charging method of the photoconductor,
The toner used for this is different, and is classified into positively charged toner and negatively charged toner.

Polyester resin has been favored as a binder resin for toner used in the pulverization method. As such a polyester resin, for example, JP-A 2000-30
5320 discloses a polyester resin comprising a polycondensate of an alicyclic polycarboxylic acid and an alicyclic polyhydric alcohol,
Polyester resin consisting of polycondensate of alicyclic polycarboxylic acid, linear aliphatic polycarboxylic acid and alicyclic polyhydric alcohol, aromatic polycarboxylic acid, alicyclic polyhydric alcohol and linear fat Polyester resin composed of polycondensation product with group polyhydric alcohol, polyester resin composed of polycondensation product of alicyclic polyhydric carboxylic acid, aromatic polyhydric carboxylic acid, alicyclic polyhydric alcohol and aromatic polyhydric alcohol Have been proposed. It is said that these polyester resins are used in combination with other binder resins, and by strictly controlling the particle size, it is possible to carry out development with high image density without causing fog or hollow defects. JP-A-5-94043 discloses a polyester resin obtained from an aromatic polycarboxylic acid having a sulfonate group, an ethanediol derivative, hydrogenated bisphenol A, and the like.
Japanese Patent Publication No. 66 proposes a polyester resin obtained from a sulfonic acid group-containing polyvalent carboxylic acid, an aromatic polyvalent carboxylic acid, and bisphenol A. However,
Even when these polyester resins are used, the stability of charging and the dispersibility of the colorant are insufficient in ultra-high-speed printing and ultra-fine color printing, and fog and image density are likely to occur. Further, color transfer or sticking may occur on the vinyl chloride resin sheet.

[0004]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is excellent in stability of charge amount, excellent dispersibility of a colorant, and a balance between low-temperature fixability and high-temperature storability. It is an object of the present invention to provide a negatively chargeable toner which is excellent in color transfer and is unlikely to stick to a resin sheet. As a result of intensive studies, the present inventor has found that a toner containing a binder resin made of a specific polyester resin has excellent stability of charge amount, excellent dispersibility of a colorant, and low temperature fixability and high temperature storage. It was found that the sex is excellent in balance, and the present invention has been completed based on these findings.

[0005]

Thus, according to the present invention, a polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof and / or a polyhydric alcohol containing a sulfonic acid group or a salt thereof ( Provided is a negatively chargeable toner containing a binder resin made of a polyester resin obtained by polycondensing A2) and an alicyclic divalent carboxylic acid compound (B), and a colorant.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The negatively chargeable toner of the present invention contains at least a binder resin and a colorant. The binder resin contained in the toner of the present invention comprises a polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof and / or a polyhydric alcohol (A2) containing a sulfonic acid group or a salt thereof, It is composed of a polyester resin obtained by polycondensing an alicyclic divalent carboxylic acid compound (B).
Incidentally, a polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof described below and / or another polyvalent carboxylic acid capable of copolycondensing with a polyhydric alcohol (A2) containing a sulfonic acid group or a salt thereof. The compound and polyhydric alcohol do not contain a sulfonic acid group or a salt thereof.

Polyvalent carboxylic acid compound (A containing a sulfonic acid group or its salt constituting a polyester resin
1) includes sulfoterephthalic acid, 5-sulfoisophthalic acid, 5-sulfoisophthalic acid methyl ester, 4-
Sulfophthalic acid, 4-sulfophthalic anhydride, 4-sulfonaphthalene-2,7-dicarboxylic acid, 5- [4-sulfophenoxy] isophthalic acid; 5-sulfohexahydroisophthalic acid, 5-sulfohexahydroisophthalic acid methyl ester , 4-sulfohexahydrophthalic acid, 4-
Aromatic polyvalent sulfonic acids such as sulfohexahydrophthalic anhydride; 5-sulfotetrahydroisophthalic acid, 5-
Sulfotetrahydroisophthalic acid methyl ester, 4-
Examples thereof include alicyclic polyvalent sulfonic acids such as sulfotetrahydrophthalic acid and 4-sulfotetrahydrophthalic anhydride; and salts thereof. Examples of the sulfonate include salts of ammonium, Li, Na, K, Mg, Ca, Cu, Fe and the like. Among these, K salt or Na salt is preferable. Further, as the polyhydric alcohol (A2) containing a sulfonic acid group or a salt thereof, 2,3-bis (hydroxymethyl) benzenesulfonic acid, 3,5-bis (hydroxymethyl) benzenesulfonic acid, 3,4- Examples thereof include bis (hydroxymethyl) benzenesulfonic acid, 2,5-bis (hydroxymethyl) benzenesulfonic acid and salts thereof. Examples of the sulfonate include salts of ammonium, Li, Na, K, Mg, Ca, Cu, Fe and the like. Among these, K salt or Na salt is preferable.

In the polyester resin contained in the toner of the present invention, a polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof and / or a polyhydric alcohol (A2) containing a sulfonic acid group or a salt thereof. The amount of is usually 0.2 of all monomers constituting the polyester resin (total of all carboxylic acid components and all alcohol components).
-30 mol%, preferably 0.5-10 mol%, more preferably 1-5 mol%. By containing the polyhydric carboxylic acid compound (A1) and / or the polyhydric alcohol (A2) as a polycondensation component, the dispersibility of the pigment in the toner is improved and the chargeability of the toner can be controlled. .

The alicyclic divalent carboxylic acid compound (B) constituting the polyester resin is a compound having an alicyclic structure and two carboxyl groups or carboxylic acid derivative groups in the molecular structure. As the alicyclic structure, a cyclopentane ring,
Examples thereof include monocyclic rings such as cyclohexane ring, cycloheptane ring and cyclohexene ring; and polycyclic rings such as norbornane ring and norbornene ring. Suitable alicyclic divalent carboxylic acid compounds include a carboxyl group or a carboxylic acid derivative group (amide group, ester group, acid anhydride group, acid halide) at each of the two carbon atoms constituting the alicyclic ring. An alicyclic divalent carboxylic acid compound formed by bonding; in particular, an alicyclic divalent carboxylic acid represented by the general formula (1) or (2) or an alkyl group such as an anhydride thereof is a substituent on the alicyclic ring Are combined as. The alkyl group preferably has 1 to 8 carbon atoms, and specifically includes a methyl group, an ethyl group, a propyl group, an isopropyl group and the like.

[0010]

[Chemical 1]

[0011]

[Chemical 2]

R in the formula (1) or (2) is an alkyl group.

The alicyclic divalent carboxylic acid compound preferably used for the polyester resin is, for example, butadiene,
It can be obtained by reacting a diene compound such as isoprene, piperylene, cyclopentadiene and the like; maleic anhydride, and optionally hydrogenating. Specific examples of the alicyclic divalent carboxylic acid compound include tetrahydroterephthalic acid, tetrahydroisophthalic acid, tetrahydrophthalic acid; hexahydroterephthalic acid, hexahydroisophthalic acid, hexahydrophthalic acid; 3-alkyltetrahydroterephthalic acid, 4- Alkyltetrahydroterephthalic acid, 3-alkyltetrahydroisophthalic acid, 4-alkyltetrahydroisophthalic acid, 3-alkyltetrahydrophthalic acid, 4-alkyltetrahydrophthalic acid;
3-alkylhexahydroterephthalic acid, 4-alkylhexahydroterephthalic acid, 3-alkylhexahydroisophthalic acid, 4-alkylhexahydroisophthalic acid, 3-alkylhexahydrophthalic acid, 4-alkylhexahydrophthalic acid; 3, 6-Endomethylene-tetrahydroterephthalic acid, 3,6-Endomethylene-tetrahydroisophthalic acid, 3,6-Endomethylene-tetrahydrophthalic acid; 3,6-Endomethylene-hexahydroterephthalic acid, 3,6-Endomethylene- Hexahydroisophthalic acid, 3,6-endomethylene-hexahydrophthalic acid;

2-alkyl-3,6-endomethylene-
Tetrahydroterephthalic acid, 3-alkyl-3,6-endomethylene-tetrahydroterephthalic acid, 2-alkyl-3,6-endomethylene-tetrahydroisophthalic acid, 3-alkyl-3,6-endomethylene-tetrahydroisophthalic acid, 2 -Alkyl-3,6-endomethylene-tetrahydrophthalic acid, 3-alkyl-3,6-
Endomethylene-tetrahydrophthalic acid; 2-alkyl-3,6-endomethylene-hexahydroterephthalic acid, 3-alkyl-3,6-endomethylene-hexahydroterephthalic acid; 2-alkyl-3,6-endomethylene- Hexahydroisophthalic acid, 3-alkyl-3,
6-endomethylene-hexahydroisophthalic acid, 2-
Alkyl-3,6-endomethylene-hexahydrophthalic acid, 3-alkyl-3,6-endomethylene-hexahydrophthalic acid;

Specific examples of the derivative of the alicyclic divalent carboxylic acid compound include tetrahydrophthalic anhydride, hexahydrophthalic anhydride, 3-alkyltetrahydrophthalic anhydride and 3-alkylhexahydrophthalic anhydride. ,
Acid anhydrides such as 4-alkyltetrahydrophthalic anhydride and 4-alkylhexahydrophthalic anhydride; halides, esters, amides and the like. They are,
Each can be used alone or in combination of two or more. Among these, 3-alkyltetrahydrophthalic acid, 3-alkylhexahydrophthalic acid,
4-alkyltetrahydrophthalic acid, 4-alkylhexahydrophthalic acid and their anhydrides have high melting characteristics, and when the polyester resin is used in the toner, a toner having excellent dispersibility of the colorant can be obtained. preferable. The amount of the alicyclic divalent carboxylic acid compound (B) is usually the amount of all polyvalent carboxylic acid components constituting the polyester resin,
It is preferably 70 to 100 mol%, particularly 80 to 100 mol%. If this ratio is too small, the toner may not have sufficient storage stability.

As a carboxylic acid component constituting the polyester resin, an aromatic divalent carboxylic acid compound (D), a chain divalent carboxylic acid compound (E) or a trivalent or higher carboxylic acid compound (G) may be used, if necessary. May be copolycondensed.
Examples of the copolycondensable aromatic divalent carboxylic acid compound (D) include 1,5-naphthalic acid, 2,6-naphthalic acid, diphenic acid, terephthalic acid, isophthalic acid, phthalic acid, and alkyl-substituted products thereof. In addition, derivatives of these acid anhydrides, halides, esters, amides and the like can be mentioned. Examples of the chain divalent carboxylic acid compound (E) include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, fumaric acid, maleic acid and itaconic acid. Trivalent or higher polycarboxylic acid compound (G)
Examples thereof include trimellitic acid, pyromellitic acid and trimesic acid. The proportion of the aromatic divalent carboxylic acid compound (D) is preferably 10 mol% or less of the total carboxylic acid components. If this ratio increases, the charge amount under high temperature and high humidity may change. The proportion of the chain-type divalent carboxylic acid compound (E) is preferably 30 mol% or less of all carboxylic acid components. When this ratio is high, the glass transition temperature and the melt viscosity are low, so that the blocking resistance of the toner may be lowered or hot offset may occur. The ratio of the trivalent or higher polyvalent carboxylic acid compound (G) is
It is preferably 5 mol% or less of all carboxylic acid components. When this ratio is high, the weight average molecular weight of the polyester resin is high, so that the melt viscosity of the toner is high and the fixing property of the toner may be deteriorated.

The polyester resin contained in the toner of the present invention is preferably further copolycondensed with a cyclic dihydric alcohol (C). Examples of the cyclic dihydric alcohol (C) include aromatic dihydric alcohols and alicyclic dihydric alcohols, and alicyclic dihydric alcohols are preferable. As the aromatic dihydric alcohol, paraxylylene glycol,
Metaxylylene glycol, orthoxylylene glycol
And ethylene oxide adducts of 1,4-phenylene glycol, bisphenol A ethylene oxide adducts and propylene oxide adducts. As the alicyclic dihydric alcohol, 2,2-bis (4
-Hydroxycyclohexyl) -propane (i.e.
Hydrogenated bisphenol A), 1,4-bis (hydroxymethyl) cyclohexane, 1,3-bis (hydroxymethyl) cyclohexane, 1,2-bis (hydroxymethyl) cyclohexane, 2,2,4,4-tetramethyl-
1,3-Cyclohexanediol, 1,4-Cyclohexanediol, Hydrogenated bisphenol A ethylene oxide adduct and propylene oxide adduct, tricyclodecanediol, tricyclodecane dimethano-
And dicyclohexyl 4,4′-diol and the like. Of these, bis (hydroxycyclohexyl) -alkanes such as hydrogenated bisphenol A are preferred.
The amount of the cyclic dihydric alcohol (C) is preferably 2 to 60 mol%, and more preferably 3 to 50 mol% of the total polyhydric alcohol component constituting the polyester resin. If the amount of the cyclic dihydric alcohol (C) is too small, the glass transition temperature and the melt viscosity may be lowered, the blocking resistance may be lowered, and hot offset may occur. When the amount of the hydric alcohol is too large, the melt viscosity becomes high and the fixability may decrease.

As another alcohol component constituting the polyester resin, it is preferable that a chain dihydric alcohol (F) is further copolycondensed. Further, trihydric or higher alcohol (H) may be copolycondensed. As the chain dihydric alcohol (F), ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-
Butanediol, 1,5-pentanediol, 1,6-
Hexanediol, diethylene glycol, polyethylene glycol, polytetramethylene glycol, and other linear aliphatic glycols; propylene glycol, dipropylene glycol, polypropylene glycol, neopentyl glycol, 2,2,4 -Trimethyl-1,3-
Pentanediol, 2-ethyl-2-butyl-1,3-
Examples thereof include branched chain aliphatic glycols such as propanediol. Among these, linear aliphatic glycols are preferable, and among them, ethylene glycol is particularly preferable. The amount of the chain-type dihydric alcohol (F) is preferably 40 to 98 mol% of the total polyhydric alcohol component constituting the polyester resin, and more preferably 50 to 97 mol%. If the amount of the chain dihydric alcohol (F) is too small, the melt viscosity may be increased and the fixability may be lowered. On the contrary, if the amount of the chain dihydric alcohol is too large,
The glass transition temperature and the melt viscosity may be lowered, the blocking resistance may be lowered, and hot offset may occur. Examples of the trihydric or higher alcohol (H) include trimethylolpropane, glycerin, pentaerythritol, dipentaerythritol, trimethylolethane,
Examples include cyclohexane triol and tris (hydroxymethyl) cyclohexane. The proportion of trihydric or higher alcohol (H) is preferably 5 mol% or less of all alcohol components. When this ratio is high, the weight average molecular weight of the polyester resin is high, so that the melt viscosity of the toner is high and the fixing property of the toner may be deteriorated.

The molecular weight of the polyester resin contained in the toner of the present invention is, when measured by gel permeation chromatography (GPC), a number average molecular weight in terms of polystyrene of 1,500 to 20,000, preferably It is 2,000 to 10,000 and the weight average molecular weight is preferably 5,000 to 300,000, preferably 7,000 to 100,000. When the molecular weight is within this range, a toner excellent in low-temperature fixing property and hot offset resistance can be obtained. If the number average molecular weight or the weight average molecular weight is smaller than the above range, the cohesive force of the resin may be reduced, and the storage stability may be deteriorated. There is. The glass transition temperature of the polyester resin is preferably 40 to 90 ° C, particularly preferably 50 to 8 ° C.
It is 0 ° C. When the glass transition temperature is within the above range, the storage stability of the toner is improved.

The polyester resin usually has a hydroxyl value of 1 to
100 mgKOH / g, preferably 5-80 mg
KOH / g. When the hydroxyl value is small, the fixability may be deteriorated, and large unevenness may occur on the surface of the image to deteriorate the smoothness. On the other hand, when it is large, the hot offset generation temperature becomes low, the hydrophilicity becomes high, and the charge amount tends to change due to environmental changes. Also,
This polyester resin preferably has fewer aromatic rings in order to reduce the influence of water in a high temperature and high humidity environment.

The polyester resin contained in the toner of the present invention can be produced by a known method, that is, a polycondensation method. In polycondensing the polyhydric carboxylic acid component and the polyhydric alcohol component, the total number of hydroxyl values of the alcoholic reactive groups [X] in all the monomers obtained by summing the polyhydric carboxylic acid component and the polyhydric alcohol component. Is preferable under the condition that the total acid value of the carboxylic acid-reactive groups is not smaller than the total number [Y] of the carboxylic acid, since the molecular weight of the polyester and the hydroxyl value can be increased. The ratio of the total number [X] of hydroxyl groups of alcoholic reactive groups to the total number [Y] of acid values of carboxylic acid reactive groups is preferably [X] / [Y] equivalent ratio of 1.00 or more. 01-1.5 are more preferable, and the range of 1.03-1.3 is especially preferable.
Here, the alcoholic reactive group refers to an alcoholic functional group that forms an ester bond, and typically includes a hydroxyl group and the like. Carboxylic acid reactive group refers to a carboxylic acid functional group that forms an ester bond,
Usually, a carboxyl group or a carboxylic acid derivative group and the like can be mentioned.

The polycondensation reaction is carried out, for example, at a reaction temperature of 100 to
It is carried out at 300 ° C., preferably 150 to 280 ° C., particularly preferably in the presence of an inert gas. If necessary, a water-insoluble organic solvent that is azeotropic with water, such as toluene or xylene, may be used. The polycondensation reaction is carried out under reduced pressure (usually 0.1 to 500 mmHg, preferably 0.5 to 500 mmHg).
200 mmHg, more preferably 1 to 50 mmHg). An esterification catalyst is usually used in this polycondensation reaction. Examples of the esterification catalyst include Bronsted acids such as paratoluenesulfonic acid, sulfuric acid, and phosphoric acid; calcium acetate, zinc acetate, manganese acetate, zinc stearate; iron and zinc acetylacetonates; metal alkoxides; alkyltin oxides. , Organoalkyl compounds such as dialkyltin oxide and organotitanium compounds: metal oxides such as tin oxide, antimony oxide, titanium oxide and vanadium oxide: heteropolyacids, etc. Alkoxides, heteropoly acids or iron acetylacetonates are preferred.

In order to obtain the polyester resin contained in the toner of the present invention, the above-mentioned carboxylic acid compound and alcohol may be charged at a desired composition ratio and reacted in a lump, and in order to adjust the molecular weight, Methods can also be used. That is, the alicyclic divalent carboxylic acid compound (B) and the cyclic dihydric alcohol (C) are preferably used.
Carboxylic acid compound (B), cyclic dihydric alcohol (C)
And a chain divalent carboxylic acid compound (E) and / or a chain dihydric alcohol (F) are polycondensed to obtain a precursor,
Then, a polyvalent carboxylic acid compound (A1) containing this precursor and a sulfonic acid group or a salt thereof and / or a polyhydric alcohol containing a sulfonic acid group or a salt thereof (A
2) and the polycarboxylic acid compound (I) and / or the polyhydric alcohol (J) are polycondensed.

The precursor has a number average molecular weight of 1,500 to 5,000 in terms of polystyrene when measured by gel permeation chromatography (GPC).
It is preferably 2,000 to 4,000. When the molecular weight is in this range, the dispersibility of the resin is high. The glass transition temperature of the precursor is preferably 40 ° C. or higher, particularly preferably 50 to 80 ° C. Glass transition temperature is 40
When it is at least ℃, the storage stability of the toner is improved.

A polyvalent carboxylic acid compound (A1) containing a precursor and a sulfonic acid group or a salt thereof and / or a polyhydric alcohol containing a sulfonic acid group or a salt thereof (A
The polyvalent carboxylic acid compound (I) to be copolycondensed with 2) is
There is no particular limitation, and as described above, the alicyclic dicarboxylic acid compound (B), the aromatic divalent carboxylic acid compound (C), the chain divalent carboxylic acid compound (E), and the trivalent or higher carboxylic acid compound ( G) etc. can be mentioned. Of these, cyclic divalent carboxylic acid compounds such as terephthalic acid, tetrahydroterephthalic acid, and hexahydroterephthalic acid, in which a carboxyl group or a carboxylic acid derivative group is bonded to two non-adjacent carbon atoms forming a ring, respectively. preferable. Polyvalent carboxylic acid compound (A1) containing precursor and sulfonic acid group or salt thereof and / or polyhydric alcohol (A2) containing sulfonic acid group or salt thereof
The polyhydric alcohol (J) to be copolycondensed with is also not particularly limited, and as described above, a cyclic dihydric alcohol (C) such as an aromatic dihydric alcohol or an alicyclic dihydric alcohol, a chain formula 2 Polyhydric alcohol (F), trihydric or higher alcohol (H)
And so on. The total amount of the polycarboxylic acid compound (I) or the polyhydric alcohol (J) used for copolycondensation with the precursor is preferably 10 to 50 parts by weight, and particularly preferably 100 parts by weight of the precursor. 20 to 40 parts by weight. When the amount of the polyvalent carboxylic acid compound or the polyhydric alcohol is in the above range, it is possible to increase the molecular weight without impairing the melting property, which is preferable.

The binder resin contained in the toner for electrophotography of the present invention may be only the above-mentioned polyester resin, but it is usually used as a binder resin for toner in order to improve the characteristics of the toner. It may contain a polymer. Specifically, polystyrene, styrene- (meth)
Acrylate copolymer resin, polyester resin other than the above, polyurethane, epoxy resin, polyolefin, polyamide, polysulfone, polycyanoaryl ether, (meth) acrylate resin, norbornene resin,
Examples thereof include a nuclear hydrogenated product of a styrene resin and a nuclear hydrogenated product of a styrene-isoprene-styrene block polymer.
Other polymers can be used as the binder resin in a proportion of 30% by weight or less with respect to the above-mentioned polyester resin. If the amount is too large, the melt viscosity of the toner becomes high and the fixability may deteriorate.

The colorants contained in the toner of the present invention include black colorants, yellow colorants, magenta colorants and cyan colorants. Examples of the black colorant include carbon black and nigrosine-based dyes and pigments; magnetic particles such as cobalt, nickel, ferrosoferric oxide, manganese iron oxide, zinc iron oxide and nickel iron oxide. When using carbon black, the primary particle size is 20-
It is preferable to use one having a thickness of 40 nm because good image quality is obtained and the safety of the toner to the environment is improved. As the yellow colorant, compounds such as azo pigments and condensed polycyclic pigments are used. Specifically, C.I. I. Pigment Yellow 3, 12, 13, 14, 15, 17, 62, 6
5, 73, 83, 90, 93, 97, 120, 138,
155, 180, 181 and the like. As the magenta colorant, compounds such as azo pigments and condensed polycyclic pigments are used. Specifically, C.I. I. Pigment Red 48, 57, 58, 60, 63, 64, 68, 81, 8
3, 87, 88, 89, 90, 112, 114, 12
2, 123, 144, 146, 149, 163, 17
0, 184, 185, 187, 202, 206, 20
7, 209, 251, C.I. I. Pigment Violet 19 and the like. As the cyan colorant, a copper phthalocyanine compound and its derivative, an anthraquinone compound or the like can be used. Specifically, C.I. I. Pigment Blue 2, 3, 6, 15, 15: 1, 15: 2, 15: 3,
15: 4, 16, 17, and 60 and the like. The amount of these colorants is usually 0.1 to 50 parts by weight, preferably 1 to 20 parts by weight, based on 100 parts by weight of the binder resin.

In the toner of the present invention, the above-mentioned polyester resin has charge controllability, and practically sufficient charge characteristics are exhibited without the use of other charge control agents. However, a conventional charge control agent may be used together for the purpose of fine adjustment. As the other charge control agent, it is possible to use various charge control agents having positive or negative chargeability. For example,
Examples thereof include metal complexes of organic compounds having a carboxyl group or a nitrogen-containing group, metal-containing dyes, nigrosine and the like. More specifically, Spiron Black TRH (Hodogaya Chemical Co., Ltd.), T-77 (Hodogaya Chemical Co., Ltd.), Bontron S-34 (Orient Chemical Co., Ltd.), Bontron E-84 (Orient Chemical Co., Ltd.) Made), Bontron N-
01 (Orient Chemical Co., Ltd.), Copy Blue-P
Charge control agents such as R (manufactured by Clariant) and / or other charge control resins such as quaternary ammonium (salt) group-containing (meth) acrylate copolymers and sulfonic acid (salt) group-containing acrylate copolymers Can be mentioned.

The toner of the present invention may contain a release agent from the viewpoints of improving low temperature fixability and preventing filming. Examples of the release agent include polyolefin waxes such as low molecular weight polyethylene, low molecular weight polypropylene, and low molecular weight polybutylene; plant-based natural waxes such as candelilla, carnauba, rice, and wax; petroleum oils such as paraffin, microcrystalline, petrolactam, etc. Examples of the wax include synthetic waxes such as Fischer-Tropsch wax; and polyfunctional ester compounds such as pentaerythritol tetramyristate, pentaerythritol tetrapalmitate, and dipentaerythritol hexamyristate. These can be used alone or in combination of two or more.

Of these, synthetic waxes (particularly Fischer-Tropsch wax), petroleum waxes, polyfunctional ester compounds and the like are preferable. Among these, in the DSC curve measured by a differential scanning calorimeter, the endothermic peak temperature during heating is 30 to 200 ° C., preferably 50.
To 180 ° C., particularly preferably 60 to 160 ° C., and a multifunctional ester compound such as dipentaerythritol ester having an endothermic peak temperature in the range of 50 to 80 ° C. is fixed as a toner. It is particularly preferable in terms of balance of releasability. In particular, it has a molecular weight of 1,000 or more, dissolves in 5 parts by weight or more at 25 ° C. in 100 parts by weight of styrene, and has an acid value of 10 mg / KO.
The dipentaerythritol ester having an H or less is significantly effective in lowering the fixing temperature. Endothermic peak temperature is ASTM
It is the value measured by D3418-82. The amount of the release agent is usually 100 parts by weight of the binder resin,
It is 0.1 to 20 parts by weight, preferably 1 to 15 parts by weight.

The toner of the present invention has a volume average particle diameter (dv).
Is usually 1 to 10 μm, preferably 3 to 8 μm, and the ratio of the volume average particle diameter to the number average particle diameter (dp) (dv /
dp) is 1 to 2.0, preferably 1 to 1.5. In addition, a value obtained by dividing the major axis rl of the toner by the minor axis rs (rl / r
s) is preferably in the range of 1 to 1.3. If this ratio becomes large, the transferability of transferring the toner image on the photoconductor to a transfer material such as paper is deteriorated, or the friction between the toners becomes large when the toner is stored in the toner storage portion of the image forming apparatus. Therefore, the external additive may peel off and the durability may be reduced.

The toner of the present invention has a melt viscosity at 120 ° C. of usually 10,000 Pa · s or less, preferably 10
0 to 10,000 Pa · s, more preferably 1,000
~ 8,000 Pa · s. With the toner having such a melt viscosity, high image quality can be achieved even by printing at high speed. Viscosity can be measured using a flow tester. Also, the softening temperature by the flow tester is
Usually, it is 50 to 80 ° C, preferably 60 to 70 ° C,
The outflow starting temperature is usually 90 to 150 ° C., preferably 10
It is 0 to 130 ° C. If the softening temperature is low, the storability may decrease, and conversely, if the softening temperature is high, the fixability may decrease. If the outflow starting temperature is low, the hot offset resistance may decrease, and conversely, if it is high, the fixability may decrease. The toner of the present invention has a glass transition temperature of usually 0 to 80 ° C., preferably 40 to 70 ° C., as measured by a differential scanning calorimeter.
Is. If the glass transition temperature is low, the storability may be lowered, and conversely, if it is high, the fixability may be lowered.

The toner of the present invention has a tetrahydrofuran (THF) insoluble content of usually 0 to 50%, preferably 0 to 20%. If it is 50% or more, the gloss decreases and the transparency deteriorates. The amount of THF-insoluble matter can be measured by the method described below. A preferred toner used in the present invention is a volume resistivity value (lo
g (Ω · cm)) is usually 10 to 13, preferably 1
0.5-12.5. If the volume resistivity value is small, fog may occur, and if it is large, toner scattering, fog, filming, or poor cleaning may occur. Further, it is preferable that the toner of the present invention has a small change in charge amount in a high temperature and high humidity environment (H / H environment) and a low temperature and low humidity environment (L / L environment), that is, high so-called environmental stability. At that time, it is preferable that the amount of change in the charge amount between the environments is 5 μC / g or less. Fogging may occur if environmental stability is low.

The toner of the present invention has a film thickness of 20 after being melted by heating.
The number of colorant particles having a major axis of 0.2 μm or more observed in an area of 100 μm × 100 μm of the toner adjusted to μm is usually
The number is 50 or less, preferably 30 or less, and more preferably 20 or less. If this number is large, the spectral characteristics such as transparency necessary for reproducing a clear color tone of a color image may be deteriorated, fog may be increased, and the print density may be lowered. The spectral characteristics can be measured by printing a solid image with a commercially available printer and measuring the color tone with a spectral color difference meter.

The electrophotographic toner of the present invention can be manufactured by a conventionally known method. That is, a binder resin, a colorant and other additives are melt-kneaded using a kneader or roll to uniformly disperse, then solidified, finely pulverized with a hammer mill or a jet mill, and an air classifier, etc. A desired toner can be prepared by classifying with.

The electrophotographic toner of the present invention can be used as it is for the development of electrophotography, but normally, in order to adjust the chargeability, fluidity, storage stability, etc. of the toner, the surface of the toner particle is adjusted. Then, fine particles having a particle diameter smaller than that of the toner particles (hereinafter referred to as an external additive) are attached or embedded and used. Examples of the external additive include inorganic particles and organic resin particles. Examples of the inorganic particles include silicon dioxide, aluminum oxide, titanium oxide, zinc oxide, tin oxide, barium titanate, and strontium titanate. As the organic resin particles, methacrylic acid ester polymer particles, acrylic acid ester polymer particles, styrene-methacrylic acid ester copolymer particles, styrene-acrylic acid ester copolymer particles, zinc stearate, calcium stearate, shell is methacrylic acid Examples thereof include core-shell type particles having an acid ester copolymer and a core formed of a styrene polymer. In the case of a magnetic one-component developer,
It may contain iron, cobalt, nickel, an alloy containing them as a main component, or an oxide such as ferrite. Among these, inorganic oxide particles, particularly silicon dioxide particles are preferable. Further, the surface of these fine particles can be subjected to a hydrophobizing treatment, and hydrophobized silicon dioxide particles are particularly preferable. The amount of the external additive is not particularly limited, but is usually 0.1 to 100 parts by weight of the toner particles.
6 parts by weight. The external additives may be used in combination of two or more kinds. When an external additive is used in combination, a method of combining inorganic particles having different average particle diameters or combining inorganic particles and organic resin particles is suitable. To attach the external additive to the toner particles, the external additive and the toner particles are usually charged in a mixer such as a Henschel mixer and stirred.

The negatively chargeable toner of the present invention has good image characteristics, fixing characteristics, blocking resistance, storage stability, vinyl chloride plasticizer resistance, and charge stability. This is because the binder resin used in the present invention realizes a low melt viscosity at a high temperature in a state where the binder resin has a relatively high glass transition temperature, and further has an affinity with a plasticizer contained in a vinyl chloride resin, an eraser or the like. Is low, it is difficult for the plasticizer to migrate to the developed toner image, and the toner image itself is dense, so the toner image is too dense.
This is because the bleeding of the coloring material in the image is suppressed. Therefore, even when a copy of the toner of the present invention is stored for a long period of time in contact with a vinyl chloride type transparent sheet or the like, color transfer or toner adhesion to the sheet is unlikely to occur.

The electrophotographic toner of the present invention exhibits excellent color fastness in coloring and high stability to a colorant, and therefore exhibits high light fastness. Further, the toner in the present invention
Has excellent transparency, and therefore, not only coloring in the case of a single color, but also good color mixing property in the case of overlapping with other colors, and thus excellent in reproducibility of intermediate colors. Further, when an image is formed on a transparent film used in an over head projector or the like, a good color tone is exhibited even in an image projected on a screen.

[0039]

EXAMPLES Next, the present invention will be described in detail with reference to examples, but the present invention is not limited to these examples. Parts and percentages in these examples are by weight unless otherwise stated. In this example, the following methods were used for evaluation. 1. Polyester resin characteristics (1) Number average molecular weight and weight average molecular weight The number average molecular weight and weight average molecular weight of polyester are G
It was calculated as a standard polystyrene conversion amount according to the PC method. (2) Hydroxyl value The hydroxyl value of polyester is "standard oil and fat analysis test method"
The measurement was carried out according to the method described in paragraphs 2, 4, 9, 2-83 of the Japan Oil Chemists' Society. The unit is mgKOH / g. (3) Glass transition temperature The glass transition temperature (Tg) of polyester resin is JIS
It was measured according to the DSC method defined in K 7121. The unit is ° C.

2 Toner characteristics (1) Toner particle size The volume average particle size (dv) and number average particle size (dp) of the polymer particles were measured by Multisizer (manufactured by Beckman Coulter, Inc.). The measurement with this Multisizer was carried out using an aperture diameter of 100 μm, a medium of Isoton II,
The number of particles measured: 100,000. (2) Toner shape The shape of the toner was photographed by a scanning electron microscope, the photograph was read by a Nexus 9000 type image processing device, and the value (rl / rs) obtained by dividing the major axis of the toner by the minor axis was measured. The number of toners measured at this time was 100. (3) Melt viscosity flow tester (manufactured by Shimadzu Corporation, model name "CFT-50"
0C ”) and the sample amount is 1.0 to 1.3 g,
The melt viscosity at 120 ° C was measured under the following measurement conditions. Starting temperature: 35 ° C, heating rate: 3 ° C / min, preheating time: 5
Min, cylinder pressure: 10.0 Kgf / cm ² , die diameter: 0.5 mm, die length 1.0 mm, shear stress:
2.451 × 10 ⁵ Pa (4) THF insoluble content 1 g of toner is precisely weighed and put into a cylindrical filter paper (86R size 28 × 100 mm, manufactured by Advantech Co., Ltd.), which is applied to a Soxhlet extractor, and THF is placed in the lower flask. Add and extract for 6 hours. After the extraction, the extraction solvent was recovered, and the soluble resin component extracted in the extraction solvent was separated by an evaporator, precisely weighed, and calculated from the following calculation. THF insoluble amount (%) = ((T−S) / T) × 100 T: toner sample amount (g) S: extracted resin amount (g)

(5) Volume resistivity value The volume resistivity value of the toner is about 3 g of toner and 5 cm in diameter.
In a tablet molding machine, a test piece is prepared by applying a load of about 100 kg for 1 minute, and a dielectric loss measuring device (manufactured by Ando Electric Co., model name "TRS-10 type") is used at a temperature of 30 ° C. ,
The measurement was performed under the condition of a frequency of 1 kHz. (6) Charge amount L / L (temperature 10 ° C, humidity 20%), H / H (temperature 35
The amount of electrification under the environment (° C, humidity 80%) was measured, and the state of the environmental fluctuation was evaluated. To charge the toner, put the toner in a commercially available non-magnetic one-component developing type printer (Oki Data Co., Ltd., trade name "Microline 3010C").
After left in the environment for one day and night, five halftone print patterns are printed, then the toner on the developing roller is sucked into a suction type charge amount measuring device, and the charge amount and the charge amount per unit weight are calculated from the suction amount. Was measured. (7) Place an appropriate amount of toner on the colorant-dispersible slide glass, put a cover glass on it, heat it to 170 ° C. on a hot plate to melt the toner, and then apply force with a cover glass. , Crushed the toner. Thickness meter (made by Anritsu Corporation,
The toner thickness measured with the product name: K-402B) is 20.
The μm portion was observed with an optical microscope, and the number of colorant particles having a major axis of 0.2 μm or more and existing in 100 μm square was counted.

3 Image quality evaluation (1) Color tone Set the printing paper in the printer described above, put the toner in the developing device, and set the temperature to 35 ° C and the humidity to 80% (H / H).
After leaving it in the environment for a whole day and night, 10 sheets were printed at a density of 5%, then solid printing was performed, and measurement was performed with a spectral color difference meter (manufactured by Nippon Denshoku Co., Ltd., model name "SE2000"). (2) Printing density Set the printing paper in the above-mentioned printer, put the toner in the developing device, and the temperature is 35 ° C and the humidity is 80% (H / H).
After left in the environment for a whole day and night, 5% density is used for continuous printing from the beginning, and solid printing is performed when printing the 20,000th sheet. Black toner is McBeth transmission type image density measuring machine, color toner is color reflection type densitometer ( X-Light, model name "4
04A ") was used to measure the print density. (3) Fog Using the printer described above, a temperature of 35 ° C. and a humidity of 80
%, (H / H) environment, left for 24 hours, continuously printed at a density of 5%, printed 20,000 sheets, then solid printed, stopped printing halfway, and left on the photoreceptor after development. The toner in the non-image area was peeled off with an adhesive tape (Scotch Mending Tape 810-3-18 manufactured by Sumitomo 3M Ltd.), and the toner was attached to a new printing paper. Black toner
Whiteness (B) of the printing paper to which the adhesive tape is attached
Was measured with a whiteness meter (manufactured by Nippon Denshoku Co., Ltd.), and similarly,
The whiteness (A) of the printing paper to which only the adhesive tape was attached was measured. The difference ΔY between the whiteness (A) and the whiteness (B) was calculated as the fog value. On the other hand, for the color toner, in the same manner as the black toner, the color tone is measured instead of the whiteness by using the above-described spectral color difference meter, and the color tone is expressed as the coordinates in the Lab space, and the color difference ΔE is calculated, and the fog value is calculated. And A smaller value indicates less fog.

(4) Fixing temperature The temperature of the fixing roll was changed to 5 ° C. by modifying it so that the temperature of the fixing roll of the printer can be changed.
Measure the fixing rate of the developer at each temperature in steps,
A fixing test was conducted to find the relationship between temperature and fixing rate. The fixing rate is 5 to stabilize the changed fixing roll temperature.
After leaving for more than a minute, solid printing was performed on the printing paper with a modified printer, and the solid area of the printed paper was calculated from the ratio of the print density before and after the tape peeling operation. That is, the fixing ratio was calculated from the following equation, where the image density before peeling the tape is before ID and the image density after the tape peeling is after ID. Fixing rate (%) = (After ID / Before ID) × 100 Here, the tape peeling operation is to stick the above-mentioned adhesive tape to the measurement portion of the test paper and press it with a constant pressure to adhere it, and then to a constant speed. Is a series of operations for peeling the adhesive tape in the direction along the paper. In this fixing test, the fixing roll temperature corresponding to a fixing ratio of 80% was defined as the fixing temperature of the developer. (5) Hot offset temperature In the same way as fixing temperature measurement, the fixing roll temperature is changed to
Solid printing was performed and the temperature at which hot offset occurred was measured. The fixing roll temperature when the hot offset occurred was defined as the hot offset temperature.

[Synthesis of bis (β-hydroxyethyl) hexahydroterephthalate] 557 parts of 1,4-cyclohexanedicarboxylic acid was placed in a three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water dividing pipe and a nitrogen gas introducing pipe. ,
And 443 parts of ethylene glycol were charged. Stirring was carried out while introducing nitrogen gas, and the reaction was carried out at 180 ° C. for 5 hours while removing water produced during the reaction. Reaction temperature 20
Raise it to 0 ° C and gradually reduce the pressure in the flask to 1.5.
After the lapse of time, the pressure was adjusted to 5 mmHg or less, and the reaction was further continued for 2 hours to obtain bis (β-hydroxyethyl) hexahydroterephthalate. Bis (β-hydroxyethyl) hexahydroterephthalate was a colorless transparent liquid.

[Synthesis of Polyester Resin] (Synthesis Example 1) 510 parts of 4-methyl-hexahydrophthalic anhydride were placed in a three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water dividing pipe and a nitrogen gas introducing pipe. Hexahydroterephthalate bis (β-hydroxyethyl) 100
Part, 5-Na sulfoisophthalic acid dimethyl ester 40
Part, 2,2-bis (4-hydroxycyclohexyl)-
200 parts of propane and 150 parts of ethylene glycol were charged. The ratio of the total number of hydroxyl values [X] / the total number of acid values [Y] is 1.14. Stirring is performed while introducing nitrogen gas, and the alcohol generated during the reaction is removed to 200
The reaction was carried out at 0 ° C for 3 hours. Next, 5 parts of tetrabutoxy titanate was added, the reaction temperature was raised to 220 ° C. and the pressure in the flask was gradually reduced to 1.5 mmHg or less after 1.5 hours, and then the reaction was continued for another 3 hours to obtain a polyester resin (1 ) Got. The resulting polyester resin (1) had a number average molecular weight of 2500 and a weight average molecular weight of 12,000.
0, the hydroxyl value was 47 mgKOH / g, and the glass transition temperature was 60 ° C.

(Synthesis Example 2) A three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water separating pipe and a nitrogen gas introducing pipe was charged with 93 parts of dimethyl terephthalate, 89 parts of dimethyl isophthalate and trimellitic acid. 8 parts, 6 parts of dimethyl 5-sodium sulfoisophthalate, 68 parts of ethylene glycol, 120 parts of 2,2-bis (4-hydroxycyclohexyl) -propane, tetrabutoxy titanate
0.1 part was charged. The mixture was stirred while introducing nitrogen gas, and the reaction was carried out at 200 ° C. for 3 hours while removing alcohol and water produced during the reaction. Next, the reaction temperature is set to 250.
The temperature in the flask was gradually lowered to 5 ° C., the pressure in the flask was gradually decreased to 5 mmHg or less after 1.5 hours, and then the reaction was continued for another 3 hours to obtain a polyester resin (2). The obtained polyester resin (2) had a number average molecular weight of 4000 and a glass transition temperature of 64 ° C.

[Production of Toner] (Example 1) Polyester resin (1) 1 as a binder resin
00 parts, 6 parts of magenta pigment (CI Pigment Violet 19; manufactured by Client Co.) as a colorant and 10 parts of dipentaerythritol hexamyristate are mixed and kneaded in a melt extruder, and then mixed on a cooling belt. It was extruded into a plate shape and cooled and solidified to obtain a toner raw material. Next, the cooled and solidified toner raw material is pulverized by a classifier and then classified, and the volume average particle diameter (dv) is 7.3 μm, and the volume average particle diameter (dv) / number average particle diameter (dp) is 1. .21, toner particles having no pigment particles present in the unit area were obtained. Hydrophobized colloidal silica (manufactured by Nippon Aerosil Co., Ltd., trade name "R"
X300 ") was added and mixed using a Henschel mixer to prepare a toner. Table 1 shows the characteristics of the obtained toner and the evaluation of images and the like.

Examples 2 to 3 In Example 1, instead of the magenta pigment (trade name "CI Pigment Violet 19" manufactured by Client Co.) as a colorant, a cyan pigment (trade name manufactured by Client Co., Ltd.) was used. “C.I.
Pigment Blue 15: 3 ") or a yellow pigment (trade name" CI Pigment Yellow 180 "manufactured by Client Co.) was used to obtain a toner in the same manner as in Example 1. Table 1 shows the characteristics of the obtained toner and the evaluation results of images.

Comparative Examples 1 to 3 In Examples 1 to 3,
Without using the polyester resin (1) as the binder resin, the polyester resin (2) obtained in Synthesis Example 2 as the binder resin, and the quaternary ammonium salt charge control agent (manufactured by Orient Chemical Industry Co., Ltd.) as the charge control agent. A toner was obtained in the same manner as in Examples 1 to 3 except that 1 part of the product (trade name "Bontron E-84") was used. Table 1 shows the characteristics of the obtained toner and the evaluation of images and the like.

[0050]

[Table 1]

From Table 1, a polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof and / or a polyhydric alcohol containing a sulfonic acid group or a salt thereof (A
The negatively chargeable toners of Comparative Examples 1 to 3 using the polyester resin in which 2) and the alicyclic divalent carboxylic acid compound (B) are not polycondensed as the binder resin have poor pigment dispersibility and color tone. It can be seen that the print density is low and there is much fog. On the other hand, a polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof and / or a polyhydric alcohol (A2) containing a sulfonic acid group or a salt thereof, and an alicyclic divalent carboxylic acid compound The negatively chargeable toners of Examples 1 to 3 using the polyester resin formed by polycondensation with (B) as the binder resin have high environmental stability, good pigment dispersibility and color tone, and high print density. It turns out that fogging can be reduced.

[0052]

INDUSTRIAL APPLICABILITY The negatively chargeable toner of the present invention has a wide interval between the fixing start temperature and the offset start temperature even in a fixing device in which a heat-resistant film capable of power saving and quick start and a thermal head are combined, and is excellent. It exhibits excellent low temperature fixing characteristics, high surface smoothness of fixed images, and high temperature storability. In addition, the stability of the charge amount is excellent and the dispersibility of the colorant is excellent, so that the reproducibility of the color image is high, a clear image can be obtained, the fog is small, and the printing density can be increased. Difficult to cause color transfer and sticking to vinyl resin sheet.

Continued front page    F-term (reference) 2H005 AA01 AB02 CA08 CA16 DA02                 4J029 AA03 AB01 AB07 AC02 AE18                       BA02 BA03 BA04 BA05 BA08                       BA10 BB06A BB06B BD02                       BD03C BD04A BD06A BD07A                       BD10 BF09 BF25 BF26 BH02                       BH07 CB04B CB05B CB06B                       CD03 CH02 CH07 DB02 HA01                       HB01 HB03A HB06 JA191                       JA251 JB131 JB171 JC361                       JF091 JF141 JF181 JF321                       JF371 JF411 JF471 JF541                       JF561

Claims (6)

[Claims] 1. A polyvalent carboxylic acid compound (A1) containing a sulfonic acid group or a salt thereof and / or a polyhydric alcohol (A2) containing a sulfonic acid group or a salt thereof,
A negatively chargeable toner containing a binder resin composed of a polyester resin obtained by polycondensing an alicyclic divalent carboxylic acid compound (B), and a colorant. 2. The negatively chargeable toner according to claim 1, wherein the binder resin is a polyester resin obtained by polycondensing a cyclic dihydric alcohol (C). 3. The negatively chargeable toner according to claim 2, wherein the binder resin is a polyester resin obtained by polycondensing a chain dihydric alcohol (E). 4. The negatively charged compound according to claim 1, wherein the alicyclic divalent carboxylic acid compound is a compound in which a carboxyl group or a carboxylic acid derivative group is bonded to each of two adjacent carbon atoms forming an alicycle. Toner. 5. The cyclic dihydric alcohol (C) is alicyclic 2
The negatively chargeable toner according to claim 2, which is a hydric alcohol. 6. The negatively chargeable toner according to claim 5, wherein the alicyclic dihydric alcohol is bis (hydroxycyclohexyl) -alkane.