JP2003233214A - Electrophotographic toner - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrophotographic toner excellent in stability of the charge amount and in dispersibility of a coloring agent, causing no fog, having high printing density, excellent balance in low temperature fixing property and high temperature storage property, and hardly causing color transfer or sticking to a resin sheet. <P>SOLUTION: The electrophotographic toner comprises a coloring agent and a binder resin. The binder resin consists of a polyester resin obtained by polymerization condensation of a cyclic divalent carboxylic acid compound (A), a cyclic dihydric alcohol (B) and a chain type dihydric alcohol (C) and having 1,500 to 20,000 number average molecular weight, 50 to 90°C glass transition temperature and 1 to 100 mgKOH/g hydroxyl value. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrophotographic toner in which the charge amount does not greatly change due to environmental changes and color transfer or adhesion to a resin sheet hardly occurs.

[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 applied to the market with the development of office automation. As an electrophotographic toner used in an electrophotographic apparatus, a binder resin is mixed with a colorant, a charge control agent, etc., kneaded, and then pulverized and further classified. Mainly used are particles produced by polymerizing a mixture of a monomer, a colorant, a charge control agent, and the like by a method such as suspension polymerization, emulsion polymerization, and dispersion polymerization, and by associating them as necessary. There is.

Polyester resin has been favored as a binder resin for toner used in the pulverization method. As such a polyester resin, for example, a polyester resin composed of a polycondensation product of an alicyclic polyvalent carboxylic acid and an alicyclic polyhydric alcohol, an alicyclic polyvalent carboxylic acid and a linear aliphatic polyvalent carboxylic acid Polyester resin composed of polycondensation product of alicyclic polyhydric alcohol, polyester resin composed of polycondensation product of aromatic polycarboxylic acid, alicyclic polyhydric alcohol and linear aliphatic polyhydric alcohol, alicyclic A polyester resin comprising a polycondensate of a polyvalent carboxylic acid, an aromatic polyvalent carboxylic acid, an alicyclic polyhydric alcohol and an aromatic polyhydric alcohol has been proposed (Japanese Patent Laid-Open No. 2000-305320).
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. However, in ultra-high speed printing and ultra-fine color printing, the charging stability and the dispersibility of the colorant are insufficient, and fog and image density decrease 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 an electrophotographic toner that is excellent and is less likely to cause color transfer or sticking to a resin sheet. As a result of earnest studies, the present inventor has found that cyclic 2
A toner containing a specific polyester resin obtained by polycondensing a polyvalent carboxylic acid compound (A), a cyclic dihydric alcohol (B), and a chain dihydric alcohol (C) as a binder resin has a stable charge amount. Excellent in dispersibility of colorant,
Furthermore, they have found that they have an excellent balance between low-temperature fixability and high-temperature storability, and have completed the present invention based on these findings.

[0005]

According to the present invention, there is thus provided an electrophotographic toner containing a colorant and a binder resin, wherein the binder resin is a cyclic divalent carboxylic acid compound (A ), A cyclic dihydric alcohol (B), and a chain dihydric alcohol (C) are polycondensed to have a number average molecular weight of 1,50.
An electrophotographic toner comprising a polyester resin having a glass transition temperature of 0 to 20,000, a glass transition temperature of 50 to 90 ° C. and a hydroxyl value of 1 to 100 mgKOH / g is provided.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION The electrophotographic toner of the present invention contains a colorant and a binder resin. Further, the binder resin has a number average molecular weight of 1,500 to which the cyclic divalent carboxylic acid compound (A), the cyclic dihydric alcohol (B), and the chain dihydric alcohol (C) are polycondensed. 20,000, glass transition temperature 50-90 ° C, hydroxyl value 1-100 mg KO
It consists of a polyester resin that is H / g.

Examples of the cyclic divalent carboxylic acid compound (A) constituting the polyester resin include an aromatic divalent carboxylic acid compound and an alicyclic divalent carboxylic acid compound, and an alicyclic divalent carboxylic acid compound is used. preferable. Examples of the aromatic divalent carboxylic acid compound include 1,5-naphthalic acid, 2,6-naphthalic acid, diphenic acid, terephthalic acid, isophthalic acid,
Examples thereof include phthalic acid and alkyl-substituted compounds thereof, and derivatives thereof such as acid anhydrides, halides, esters and amides.

The alicyclic divalent carboxylic acid compound is a compound having an alicyclic structure and two carboxyl groups or two carboxylic acid derivative groups in its molecular structure. As an alicyclic structure,
Examples thereof include monocyclic rings such as cyclopentane ring, 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 anhydride thereof, in which an alicyclic ring is substituted It is bonded as a group. In addition,
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.

[0009]

[Chemical 1]

[0010]

[Chemical 2]

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

The alicyclic divalent carboxylic acid compound preferably used in the present invention is, for example, a diene compound such as butadiene, isoprene, piperylene or cyclopentadiene; and maleic anhydride, and optionally hydrogenated. It is obtained by doing. 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 are preferable because a toner excellent in meltability and dispersibility of the colorant can be obtained.
The amount of the cyclic divalent carboxylic acid compound (A) is usually 70 to 70% of the total polyvalent carboxylic acid component constituting the polyester resin.
It is preferably 100 mol%, particularly preferably 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, a chain divalent carboxylic acid compound (D) may be copolycondensed, if necessary. Copolycondensable chain formula 2
Examples of the carboxylic acid compound (D) include succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, fumaric acid, maleic acid and itaconic acid. The proportion of the chain-type divalent carboxylic acid compound (D) is preferably 30 mol% or less of all carboxylic acid components. When this ratio is large, the glass transition temperature of the polyester resin may be lowered, and the blocking resistance of the toner may be lowered.

Examples of the cyclic dihydric alcohol (B) constituting the polyester resin include aromatic dihydric alcohols and alicyclic dihydric alcohols, and alicyclic dihydric alcohols are preferable. Examples of the aromatic dihydric alcohol include paraxylylene glycol, metaxylylene glycol, orthoxylylene glycol, ethylene oxide adduct of 1,4-phenylene glycol, and bisphenol A ethylene oxide. Examples thereof include adducts and propylene oxide adducts. As the alicyclic dihydric alcohol, 2,
2-bis (4-hydroxycyclohexyl) -propane (ie 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
Examples thereof include ethylene oxide adducts and propylene oxide adducts of bisphenol A, tricyclodecanediol, tricyclodecane dimethanol, and dicyclohexyl 4,4′-diol. Of these, bis (hydroxycyclohexyl) -alkanes such as hydrogenated bisphenol A are preferred. The amount of the cyclic dihydric alcohol (B) is 2 to the total amount of the polyhydric alcohol component constituting the polyester resin.
It is preferably 60 mol% and more preferably 3 to 50 mol%. If the amount of the cyclic dihydric alcohol (B) is too small, the glass transition temperature and the melt viscosity may decrease, the blocking resistance may decrease, 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 the chain dihydric alcohol (C) constituting the polyester resin, ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1, Linear aliphatic glycols such as 6-hexanediol, diethylene glycol, polyethylene glycol and polytetramethylene glycol; propylene glycol, dipropylene glycol, polypropylene glycol, neopentyl glycol, 2,2 And branched-chain aliphatic glycols such as 4-trimethyl-1,3-pentanediol and 2-ethyl-2-butyl-1,3-propanediol. Among these, linear aliphatic glycols are preferable, and among them, ethylene glycol is particularly preferable. The amount of the chain-type dihydric alcohol (C) is preferably 40 to 98 mol%, more preferably 50 to 97 mol% of the total polyhydric alcohol component constituting the polyester resin. If the amount of the chain dihydric alcohol (C) is too small, the melt viscosity may be increased and the fixability may be deteriorated. Conversely, 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.

The polyester resin contains, as a crosslinking component,
It is preferable to copolycondensate the trivalent or higher carboxylic acid compound (E) or the trivalent or higher valent alcohol (F). In that case, these trivalent or higher carboxylic acid compounds (E) or 3
You may use together alcohol (F) more than the valence. Examples of the trivalent or higher carboxylic acid compound (E) include trimellitic acid,
Examples include pyromellitic acid and trimesic acid. Examples of the trihydric or higher alcohol (F) include trimethylolpropane, glycerin, pentaerythritol, dipentaerythritol, trimethylolethane, cyclohexanetriol, and tris (hydroxymethyl) cyclohexane. When used alone, the proportion of the trivalent or higher carboxylic acid compound (E) or the trivalent or higher valent alcohol (F) is preferably 5 mol% or less of the total carboxylic acid component or the total alcohol component, respectively. In that case, the total amount is preferably 5 mol% or less of all the monomers constituting the polyester resin (the total of all carboxylic acid components and all alcohol components). When this ratio is large, the weight average molecular weight of the polyester is high, so that the melting property of the toner is deteriorated and the fixing property is deteriorated.

The polyester resin has a number average molecular weight of 1,50 in terms of polystyrene when measured by gel permeation chromatography (GPC).
0 to 20,000, preferably 2,000 to 10,000
And the weight average molecular weight is preferably 5,000 to
300,000, preferably 7,000-100,000
It is 0. 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 used in the toner of the present invention is preferably 50 to 90 ° C, particularly preferably 55 to 80 ° C. When the glass transition temperature is in this range, the storage stability of the toner is improved.

The hydroxyl value of the polyester resin is 1 to 10
0 mgKOH / g, preferably 5-80 mgKO
H / 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. Further, the polyester resin contained in the electrophotographic toner of the present invention, in order to reduce the influence of water in a high temperature and high humidity environment,
It is preferable to have fewer aromatic rings.

The polyester resin can be produced by a known method (ie, polycondensation reaction). 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 values 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, 1.0
The range of 3 to 1.3 is particularly 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. The carboxylic acid reactive group refers to a carboxylic acid functional group that forms an ester bond, and usually includes a carboxyl group or a carboxylic acid derivative group.

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, The method of can also be used. That is, cyclic dihydric carboxylic acid compound (A), cyclic dihydric alcohol (B) and chain dihydric alcohol (C)
Is polycondensed to obtain a precursor, and then the precursor is polycondensed with the polycarboxylic acid compound (G) and / or the polyhydric alcohol (H).

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.

The polyvalent carboxylic acid compound (G) to be copolycondensed with the precursor is not particularly limited, and the cyclic dicarboxylic acid compound such as the aromatic divalent carboxylic acid compound and the alicyclic dicarboxylic acid compound as described above is used. Examples thereof include a valent carboxylic acid compound (A), a chain divalent carboxylic acid compound (D) and a trivalent or higher valent carboxylic acid compound (E). 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. Polyhydric alcohol (H) to be copolycondensed with the precursor,
There is no particular limitation, and as described above, a cyclic dihydric alcohol (B) such as an aromatic dihydric alcohol or an alicyclic dihydric alcohol, a chain dihydric alcohol (C), and a trihydric or higher alcohol (F ) And the like. The total amount of the polycarboxylic acid compound (H) or the polyhydric alcohol (I) used for copolycondensation with the precursor is preferably 10 to 50 parts by weight, and particularly preferably 100 parts by weight of the precursor. Two
It is 0 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.
Colorants used in 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 carbon black is used, it is preferable to use one having a primary particle size of 20 to 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, 65, 73, 83, 9
0, 93, 97, 120, 138, 155, 180 and 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, 83, 87, 88, 8
9, 90, 112, 114, 122, 123, 144,
146, 149, 163, 170, 184, 185, 1
87, 202, 206, 207, 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, 1
5: 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.

The toner of the present invention may contain a charge control agent, a release agent, etc. in addition to the binder resin and the colorant. As the charge control agent, a charge control agent conventionally used for toner can be used. For example, Bontron N
01 (manufactured by Orient Chemical Industry), Nigrosine Base E
X (manufactured by Orient Chemical Industry), Spiron Black TR
H (Hodogaya Chemical Co., Ltd.), T-77 (Hodogaya Chemical Co., Ltd.), Bontron S-34 (Orient Chemical Co., Ltd.), Bontron E-81 (Orient Chemical Co., Ltd.), Bontron E-84 (Orient Chemical). Chemical Industry Co., Ltd.), COPY CHARGE NX (Clariant Co., Ltd.), COPY CHARGE NEG (Clariant Co., Ltd.) and the like.
-60458, JP-A-3-175456,
JP-A-3-243954, JP-A-11-1519
A quaternary ammonium (salt) group-containing copolymer produced according to the description in JP-A No. 2 or the like, or a sulfonic acid (produced according to the description in JP-A No. 1-217464 or JP-A No. 3-15858). The salt) group-containing copolymer can also be used as a charge control agent (charge control resin).

Of these, it is preferable to use the charge control resin. The charge control resin is preferable because it has high compatibility with the binder resin, is colorless, and can provide a toner having stable chargeability even in continuous color printing at high speed. The glass transition temperature of the charge control resin is usually 40 to 8
0 ° C, preferably 45 to 75 ° C, more preferably 45
~ 70 ° C. If it is lower than this range, the storage stability of the toner deteriorates, and conversely if it is higher, the fixing property may deteriorate. The amount of the charge control agent is usually 100 parts by weight of the binder resin,
It is 0.01 to 20 parts by weight, preferably 0.1 to 10 parts by weight.

Examples of the releasing 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 waxes such as paraffin, microcrystalline and petrolactam; synthetic waxes such as Fischer-Tropsch wax; pentaerythritol tetramyristate, pentaerythritol tetrapalmitate,
Examples thereof include polyfunctional ester compounds such as 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.

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.

A preferred toner used in the present invention is a volume resistivity value (log (Ω · cm)) measured by a dielectric loss measuring instrument.
Is usually 10 to 13, preferably 10.5-12.5. If the volume resistivity value is small, fog may occur, and if it is large, toner scattering, fog,
Filming or poor cleaning may occur. In addition, the toner of the present invention is used in a high temperature and high humidity environment (H / H
Environment), low change in charge amount in a low temperature and low humidity environment (L / L environment), that is, high so-called environmental stability is preferable. 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 having a size of 50 μm is 50 or less, preferably 30 or less, 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. For the spectral characteristics, solid printing is performed for each color with a commercially available printer, and the color tone is measured 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 electrophotographic 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. This is because the plasticizer is less likely to migrate to the developed toner image because the toner image is low and the toner image itself is dense, so that the bleeding of the coloring material in the toner 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 polymer particles were measured with a 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) Using a melt viscosity flow tester (CFT-500C, manufactured by Shimadzu Corporation), the sample amount was 1.0 to 1.3 g, and 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

(3) Volume resistivity value The toner has a volume resistivity value of about 3 g of toner and a diameter of 5 cm.
In a tablet molding machine, and a load of about 100 kg is applied for 1 minute to prepare a test piece, which is then measured with a dielectric loss measuring device (trade name: T
RS-10 type, manufactured by Ando Electric Co., Ltd.) was used, and the temperature was 30 ° C. and the frequency was 1 kHz. (4) 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. The charge amount of the toner is determined by placing the toner in a non-magnetic one-component developing type printer (Oki Data Co., Ltd., trade name "Microline 3010C"), leaving it in the environment for one day and night, and then printing five halftone print patterns. After printing, the toner on the developing roller was sucked into a suction type charge amount measuring device, and the charge amount per unit weight was measured from the charge amount and the suction amount. (5) 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 printing paper on a commercially available non-magnetic one-component development type printer (Oki Data Co., Ltd., trade name "Microline 3010C"), put toner in the developing device, and the temperature is 35 ° C and the humidity is 80. After standing for 24 hours under a (H / H) environment, solid printing was performed at a density of 5%, 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 on a commercially available non-magnetic one-component development type printer (Okidata Co., Ltd., trade name "Microline 3010C"), put toner in the developing device, and the temperature is 35 ° C and the humidity is 80%. (H / H) environment, left standing overnight, 5% density, continuous printing from the beginning, solid printing when printing the 20,000th sheet, black toner is McBeth transmission image density measuring device, color toner is Color reflection type densitometer (X-
The print density was measured using a model name “404A” manufactured by Wright Corporation. (3) Fog Using the printer described above, a temperature of 35 ° C. and a humidity of 80
% (H / H) environment, left for 24 hours, then continuously printed at a density of 5%, after printing 20,000 sheets, the printing was stopped halfway, and the toner in the non-image area on the photoreceptor after development Was peeled off with an adhesive tape (Scotch Mending Tape 810-3-18 manufactured by Sumitomo 3M Limited), and it was attached to a new printing paper. As for the black toner, the whiteness (B) of the printing paper to which the adhesive tape is attached is measured by a whiteness meter (manufactured by Nippon Denshoku Co., Ltd.), and similarly, the whiteness of the printing paper to which only the adhesive tape is attached. The degree (A) was measured. The difference ΔY between the whiteness (A) and the whiteness (B) was calculated as the fog value. On the other hand, color toner is similar to black toner,
The above-described spectral color difference meter was used to measure the color tone instead of the whiteness, and the color tone was expressed as the coordinates in the Lab space, and the color difference ΔE was calculated to obtain the fog value. A smaller value indicates less fog.

(4) Fixing temperature The temperature of the fixing roll is changed to 5 ° C. by modifying the fixing roll of the printer so that the temperature 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 means that an adhesive tape (Scotch Mending Tape 810-3-18 manufactured by Sumitomo 3M Co., Ltd.) is attached to the measurement portion of the test paper. This is a series of operations in which the pressure-sensitive adhesive tape is pressed and attached at a constant pressure, and then the adhesive tape is peeled in a direction along the paper at a constant speed. 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] (Synthesis Example 1) 1,4-, 3-hexylamine was placed in a three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water diversion tube, and a nitrogen gas introduction tube.
557 parts of cyclohexanedicarboxylic acid and 443 parts of ethylene glycol were charged. Stirring is carried out while introducing nitrogen gas, and while removing water generated during the reaction, 180
The reaction was carried out at 0 ° C for 5 hours. Raise the reaction temperature to 200 ° C and gradually reduce the pressure in the flask, and after 5 hours, 5 mm
After the pressure was reduced to Hg or less, the reaction was continued for another 2 hours to obtain bis (β-hydroxyethyl) hexahydroterephthalate. Bis (β-hydroxyethyl) hexahydroterephthalate was a colorless transparent liquid.

[Synthesis of Polyester Resin] (Synthesis Example 2) In a three-necked flask equipped with a stirrer, a thermometer, a reflux cooling tube, a water dividing tube and a nitrogen gas introducing tube, 545 parts of 4-methyl-hexahydrophthalic anhydride was prepared. 2,2-bis (4-hydroxycyclohexyl) -propane 284
Parts and 171 parts of ethylene glycol. The ratio of the total number of hydroxyl values [X] / the total number of acid values [Y] is 1.21. Stirring was carried out while introducing nitrogen gas, and the reaction was carried out at 200 ° C. for 3 hours while removing water produced during the reaction.
Next, 0.5 part 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. (I) was obtained.
The obtained polyester resin (I) had a number average molecular weight of 2,050, a weight average molecular weight of 8,000, a hydroxyl value of 68 mgKOH / g, and a glass transition temperature of 62 ° C.

(Synthesis Example 3) 4-methyl-hexahydrophthalic anhydride 542 was placed in a three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a water diversion tube and a nitrogen gas inlet tube.
Part, 2,2-bis (4-hydroxycyclohexyl)-
343 parts of propane, 14 parts of pentaerythritol and 101 parts of ethylene glycol were charged. The ratio of total hydroxyl value [X] / acid value [Y] is 1.05. Stirring was carried out while introducing nitrogen gas, and the reaction was carried out at 200 ° C. for 3 hours while removing water produced during the reaction. Next, 1.0 part of iron acetylacetonate 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 the reaction was continued for another 4 hours. Resin (II) was obtained. The obtained polyester resin (II) had a number average molecular weight of 3,440, a weight average molecular weight of 28,000 and a hydroxyl value of 53 mgKO.
The H / g and glass transition temperature were 70 ° C.

Reference Example 1 In a three-necked flask equipped with a stirrer, a thermometer, a reflux condenser, a diversion tube and a nitrogen gas inlet tube, 93 parts of 1,4-cyclohexanedicarboxylic acid,
7 parts of 1,3,5-cyclohexanetricarboxylic acid, 60 parts of hydrogenated bisphenol A and 40 parts of 1,4-cyclohexanediol were charged. Stirring while introducing nitrogen gas, 200 ° C while removing water generated during the reaction
And reacted for 5 hours. 0.5 parts of iron acetylacetonate was added, the reaction temperature was raised to 220 ° C. and the pressure in the flask was gradually decreased to 1.5 mmHg or less after 1.5 hours, and the reaction was further continued for 5 hours.
II) was obtained. Obtained polyester resin (III)
Has a number average molecular weight of 8,500 and a weight average molecular weight of 2
It was a light yellow transparent solid having a glass transition temperature of 8,000 and a glass transition temperature of 62 ° C.

[Production of Toner] (Example 1) Styrene / butyl acrylate / N, N-diethyl-N-methyl-2- (methacryloyloxy) ethylammonium p-toluenesulfonic acid copolymer (as a charge control resin) 24 parts of methyl ethyl ketone and 6 parts of methanol were dispersed in 100 parts of a weight average molecular weight of 18,000, a glass transition temperature of 60 ° C., and a functional group amount of 3%), and the mixture was kneaded with a roll while cooling. When the resin was wound around the roll, 100 parts of magenta pigment (CI Pigment Violet 19; manufactured by Client Co.) was gradually added and kneading was carried out for 1 hour. At this time, the roll gap was initially 1 mm, then gradually widened, and finally 3 mm.
And the organic solvent (methyl ethyl ketone / methanol = 4/1 mixed solvent) was added several times according to the kneading state of the resin. After kneading, the organic solvent component was removed to produce a charge control resin composition. Polyester resin (I) as binder resin
100 parts, 12 parts of the charge control resin composition and 10 parts of dipentaerythritol hexamyristate are mixed,
After kneading with a melt extruder, it was extruded in a plate shape on a cooling belt and solidified by cooling 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 7.4 μm, and the volume average particle diameter (dv) / number average particle diameter (dp) is 1. .21, and the number of the pigment particles present in the unit area is 1. To 100 parts of the toner particles obtained as described above, 0.6 part of hydrophobized colloidal silica (manufactured by Clariant, trade name "HDK2150") 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.

Example 2 A toner was obtained in the same manner as in Example 1 except that the polyester resin (II) was used as the binder resin instead of the polyester resin (I). Table 1 shows the characteristics of the obtained toner and the evaluation results of images.

Examples 3 to 4 In Example 2, instead of the magenta pigment (CI Pigment Violet 19; manufactured by Client Co.) as the colorant, a yellow pigment (CI Pigment Yellow 180: Clariant Co., Ltd.) was used. Manufactured by K.K.) and cyan pigment (CI Pigment Blue 15-
3: Toner was obtained in the same manner as in Example 2 except that (Clariant) was used. Table 1 shows the characteristics of the obtained toner and the evaluation results of images.

Example 5 In Example 1, the polyester resin (II) was used as the binder resin instead of the polyester resin (I), and the salicylic acid metal salt-based charge was used as the charge control agent instead of the charge control resin composition. Control agent (trade name "Bontron P-51" manufactured by Orient Chemical Industry Co., Ltd.) 2
Carbon black (made by Mitsubishi Chemical Co.,
A toner was obtained in the same manner as in Example 1 except that 7 parts of the product name "# 25B") was used. Table 1 shows the characteristics of the obtained toner and the evaluation results of images.

Comparative Examples 1 to 4 In Examples 2 to 5,
Instead of the polyester resin (II) as the binder resin,
Toners were obtained in the same manner as in Examples 2 to 5, except that the polyester resin (III) produced in Reference Example was used. Table 1 shows the characteristics of the obtained toner and the evaluation of images and the like.

[0053]

[Table 1]

From Table 1, the toners of Comparative Examples 1 and 4 in which the polyester resin specified in the present invention is not used as the binder resin have poor low-temperature fixability and often have fog in a high temperature and high humidity environment. Recognize. On the other hand, it can be seen that the toner of the present invention has excellent low-temperature fixability, high environmental stability, good pigment dispersibility, little fog, and high print density.

[0055]

The toner for electrophotography according to the present invention is power saving,
Even in a fixing device in which a heat-resistant film capable of quick start and a thermal head are combined, good low-temperature fixing characteristics, wide spacing between the fixing temperature and the offset start temperature, and high-temperature storability are exhibited. 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.

Claims (7)

[Claims] 1. An electrophotographic toner containing a colorant and a binder resin, wherein the binder resin is a cyclic divalent carboxylic acid compound (A), a cyclic divalent alcohol (B), and Chain type 2
The polyhydric alcohol (C) is polycondensed to have a number average molecular weight of 1,500 to 20,000 and a glass transition temperature of 50 to 9
An electrophotographic toner comprising a polyester resin having a hydroxyl value of 1 to 100 mgKOH / g at 0 ° C. 2. An electrophotographic toner containing a colorant and a binder resin, wherein the binder resin is a cyclic divalent carboxylic acid compound (A), a cyclic divalent alcohol (B), a chain. Formula Dihydric alcohol (C) and trivalent or higher carboxylic acid compound (E)
Alternatively, polycondensation of trivalent or higher alcohol (F) has a number average molecular weight of 1,500 to 20,000, a glass transition temperature of 50 to 90 ° C., and a hydroxyl value of 1 to 100 mgKOH /
An electrophotographic toner comprising a polyester resin of g. 3. The cyclic divalent carboxylic acid compound (A) is any of an alkyl group-substituted phthalic acid, an alkyl group-substituted tetrahydrophthalic acid, an alkyl group-substituted hexahydrophthalic acid, or an acid anhydride thereof. 1 or 2
The described electrophotographic toner. 4. The electrophotography according to claim 3, 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. For toner. 5. The toner for electrophotography according to claim 4, wherein the alicyclic divalent carboxylic acid compound is either an alkyl group-substituted tetrahydrophthalic acid, an alkyl group-substituted hexahydrophthalic acid, or an acid anhydride thereof. 6. The cyclic dihydric alcohol (B) is an alicyclic group 2
The electrophotographic toner according to claim 1, which is a polyhydric alcohol. 7. The toner for electrophotography according to claim 6, wherein the alicyclic dihydric alcohol is bis (hydroxycyclohexyl) -alkane.