JP3345354B2 - Toner binder for electrostatic image development - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner binder for developing an electrostatic image used in electrophotography, electrostatic recording, electrostatic printing and the like.

[0002]

2. Description of the Related Art Conventionally, as a method of developing an electrostatic image using toner in electrophotography, electrostatic recording, electrostatic printing, etc., an electrostatic latent image is formed on a photoreceptor by a conventional method, After development, the toner image is transferred onto copy paper, and then heat-fixed (usually using a heat roller) to obtain a copy. In this case, from the viewpoint of energy saving and simplification of a copying machine or the like, the toner can be fixed even at a lower temperature of the heat roller (low-temperature fixing property) and the toner is fused to the heat roller even at a high heat roller temperature. (Hot offset resistance) is not required. In recent years, the use of polyester resins has been proposed because of their excellent low-temperature fixability and hot offset resistance.
Japanese Patent No. 37355 proposes a polyester using trimellitic anhydride. Also, U.S. Pat.
No. 682 proposes a polyester resin using an oxyalkylene ether of a novolak type resin.
JP-A-60-98444 proposes a resin obtained by reacting a crosslinkable polyester resin with an epoxy compound.

[0003]

However, all of the resins proposed above have practically insufficient low-temperature fixability and offset resistance.

[0004]

Means for Solving the Problems The present inventors have intensively studied to obtain a toner binder having excellent offset resistance while maintaining the low-temperature fixing property, which is a characteristic of the polyester resin, and have reached the present invention.

That is, the present invention comprises a crosslinked polyester resin of a carboxylic acid (A) with a diol (B) and an oxyalkylene ether (C) of a novolak type resin, a novolak type epoxy resin and an epi-bis type epoxy resin. A THF-insoluble content of 2 to 60 obtained by reacting at least one epoxy compound (D) selected from the group;
It is a toner binder for developing an electrostatic image composed of a resin by weight.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. Specific examples of the carboxylic acids (A) in the present invention include (1)
Aliphatic dicarboxylic acids having 2 to 20 carbon atoms (maleic acid, fumaric acid, succinic acid, adipic acid, sebacic acid, malonic acid, azelaic acid, mesaconic acid, citraconic acid, glutaconic acid, etc.); 20 alicyclic dicarboxylic acids (such as cyclohexanedicarboxylic acid and methylmedic acid); (3) aromatic dicarboxylic acids having 8 to 20 carbon atoms (such as phthalic acid, isophthalic acid, terephthalic acid, toluenedicarboxylic acid, and naphthalenedicarboxylic acid); (4) Alkyl or alkenyl (anhydrous) dodecenyl succinate (anhydrous) having a hydrocarbon group of 4 to 35 carbon atoms in the side chain
Succinic acid, pentadodecenyl (anhydride) succinic acid, etc .;
A trivalent or higher aromatic carboxylic acid having 9 to 20 carbon atoms (1, 1)
2,4-benzenetricarboxylic acid, pyromellitic acid, etc.); and anhydrides and lower alkyl (methyl, ethyl, butyl, etc.) esters of these carboxylic acids. Among them, the above-mentioned (1), (3), (4) and anhydrides and lower alkyl esters of these dicarboxylic acids are preferable, and (anhydride) maleic acid, fumaric acid, isophthalic acid, terephthalic acid, dimethyl terephthalate, dodecenyl ( Succinic anhydride) is more preferred. (Anhydride) maleic acid and fumaric acid are preferred in terms of high reactivity, and isophthalic acid and terephthalic acid are preferred in terms of increasing the glass transition temperature of the polyester.

Specific examples of the diols (B) in the present invention include (1) alkylene glycols having 2 to 12 carbon atoms (ethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-propylene glycol). Butanediol, neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, etc.); (2) alkylene ether glycols (diethylene glycol, triethylene glycol, dipropylene glycol, polyethylene) (3) alicyclic diols having 6 to 30 carbon atoms (1,
4-cyclohexanedimethanol, hydrogenated bisphenol A, etc.); and (4) bisphenols (bisphenol A, bisphenol F, bisphenol S, etc.); and (5) alkylene oxide / ethylene oxide of the above bisphenols (hereinafter abbreviated as EO). ), Propylene oxide (hereinafter abbreviated as PO), butylene oxide, and the like. Of these, (1) and (5) are preferred.
More preferably, it is (5), and usually 3 of all diols
0 mol% or more, preferably 45 mol% or more, more preferably 60 mol% or more.

In the present invention, the oxyalkylene ether (C) of the novolak type resin is used as the novolak type resin (c).
An alkylene oxide (c2) adduct of 1),
(C1) is a phenol (phenol or C 1-35)
A substituted phenol having at least one hydrocarbon group and / or a halogen group as a substituent, a mixture thereof,
Phenol, cresol, and t-butylphenol are preferable) and aldehydes (formalin, paraformaldehyde, trioxane, etc.) produced by polycondensation (phenol novolak resin, cresol novolak resin, etc.), and (c2) Specific examples include ethylene oxide (hereinafter abbreviated as EO) and PO (hereinafter abbreviated as EO).
PO), 1,2-butylene oxide, 2,3-butylene oxide and the like. The average number of moles of (c2) added to one phenolic hydroxyl group in (c1) is usually 0.5 to 10 mol, preferably 0.7-5
Mole, more preferably 0.8 to 3 mole.

The epoxy compound (D) in the present invention is at least one selected from the group consisting of novolak type epoxy resins and epi-bis type epoxy resins. Specific examples of the novolak type epoxy resin and the epi-bis type epoxy resin include (1) a novolak type epoxy resin [a resin obtained by reacting epichlorohydrin with a phenol novolak resin or a cresol novolak resin; Representative products such as Epicoat 152, 154 (Yuika Shell Epoxy), EPPN-201 (Nippon Kayaku Co., Ltd.), and Epicron N-740 (Dainippon Ink and Chemicals, Inc.) can be obtained, and cresol can be obtained. Epiclon N-670 and N-680 are typical products of novolak type epoxy resin.
(Manufactured by Dainippon Ink and Chemicals, Inc.), EOCN-1020
(Manufactured by Nippon Kayaku Co., Ltd.) and the like. ];
(2) Epi-bis type epoxy resin [resin obtained by reacting epichlorohydrin with bisphenol A or bisphenol F, and obtained as typical products such as Epicoat 828, 1001, 1004 (manufactured by Yuka Shell Epoxy) Can be used].

In the present invention, the crosslinking polyesterification reaction by (A), (B) and (C) is usually carried out in the presence of a catalyst, usually at 150 to 300 ° C, preferably 170 to 280 ° C, more preferably 200 to 260 ° C. It is performed under a temperature condition of ° C. The reaction can be performed under normal pressure, reduced pressure, or increased pressure. Next, the reaction between the crosslinked polyester resin and (D) is usually 120 to 300 ° C, preferably 150 to 280 ° C.
C., more preferably 180 ° C. to 260 ° C. The reaction can be performed under normal pressure, reduced pressure, or increased pressure.

The ratio of (A), (B) and (C) constituting the crosslinked polyester, which is an intermediate of the present invention, is determined by the following formula: [sum of moles of alcohol component (moles of (B) and (C)] Of the carboxylic acid component] is usually 0.6 to
The ratio may be 0.5, preferably 0.7 to 1.4, and more preferably 0.8 to 1.3. (C)
Is generally used in a proportion of 1 to 35% by weight, preferably 2 to 30% by weight, more preferably 4 to 25% by weight, based on the total charged weight of (A), (B) and (C). Next, (D)
Is usually 1 to 50% by weight, preferably 2 to 50% by weight, based on (C).
It is used in a proportion of 40% by weight, more preferably 4 to 30% by weight.

As an example of the method for producing the resin of the present invention, first, (A), (B) and (C) are mixed at a predetermined ratio, and a polyesterification reaction is performed to obtain a crosslinked polyester resin as an intermediate. . (A), (B),
Part of (C) may be added to the reaction system during the reaction.
Examples of the catalyst include those usually used for polyesterification, for example, metals such as tin, titanium, antimony, manganese, nickel, zinc, lead, iron, magnesium, calcium, and germanium; and compounds containing these metals (dibutyltin oxide, orthodibutyl). Titanate, tetrabutyl titanate, zinc acetate, lead acetate, cobalt acetate, sodium acetate, antimony trioxide, etc.). Next, a normal epoxy reaction catalyst (tertiary amines, imidazoles, quaternary ammonium salts, etc.) may be newly added to the reaction between the crosslinked polyester resin and (D). As the reactor, a usual batch-type reactor, horizontal reactor (plast mill, kneader, extruder, or the like) can be used.

In the present invention, the THF insoluble content indicates the weight% of the THF insoluble content of the binder resin and is determined as follows. 0.500 binder resin through 18 mesh sieve
± 0.005 g was weighed (W1 g) and equipped with a cooling tube 2
Reflux with 50 ml of THF for 1 hour in a 00 ml flask. This is filled with Celite 545 to a thickness of about 2.5 cm, weighed (W2 g), and filtered by suction using a glass filter of about 3 cm in diameter, and then washed with 50 ml of THF. The glass filter after filtration is 80 ° C., pressure 30 mm
Dry under reduced pressure for 1 hour below Hg and weigh (W3g).
The THF-insoluble matter (% by weight) is calculated as ((W3-W2) / W1) × 100.

The THF-insoluble content of the resin of the present invention is usually from 2 to 6
0% by weight, preferably 10 to 45% by weight, more preferably 20 to 40% by weight. If it is less than 2% by weight, the offset resistance of the toner is insufficient, and if it exceeds 60% by weight, the low-temperature fixability is reduced.

The storage elastic modulus of the resin of the present invention is 6 × 10 ⁴ dyne / c at a measurement frequency of 20 Hz.
m ² temperature (TG1) is usually 110 ° C. to 230 ° C.,
Preferably from 120 ° C. to 210 ° C., more preferably 13 ° C.
Temperature (Tη) at 5 ° C. to 195 ° C. and a viscosity of 1 × 10 ⁴ poise at a measurement frequency of 20 Hz is usually 90.
C. to 160C, preferably 95C to 150C, and more preferably 105 to 135C. TG1 and Tη
Is determined by measuring the storage elastic modulus and the complex viscosity while changing the measurement temperature using a commercially available dynamic viscoelasticity measuring device.

The acid value of the resin of the present invention is usually 25 or less, preferably 18 or less, more preferably 16 or less from the viewpoint of the humidity dependence of the charge amount. The number average molecular weight of the resin of the present invention is usually 1,000 to 12,000, preferably 15
00 to 9000, more preferably 2000 to 7
000.

Tg (glass transition temperature) of the resin of the present invention
Is usually from 40 to 85 ° C, preferably from 45 to 80 ° C, more preferably from 50 to 75 ° C, from the viewpoints of adhesion, aggregation (blocking) and low-temperature fixability between toner particles.

The softening point of the resin of the present invention is usually 100 to 18.
0 ° C., preferably 120-160 ° C.

The binder of the present invention may contain another resin for a toner binder if necessary. Other resins for the toner binder include polystyrene resin and styrene-
Acrylic copolymer resin, styrene-butadiene copolymer resin, styrene-acrylonitrile copolymer resin, styrene-acryl-acrylonitrile copolymer resin, polyurethane resin, polyamide resin, epoxy resin, polyester resins other than the present invention, and the like. Can be

As an example of a method for producing a toner for developing an electrostatic image, which is used for the binder of the present invention, the toner binder is usually 45 to 95% by weight based on the toner weight, and a known coloring agent (carbon black, iron black, Sudan Black S
M, Fast Yellow-G, Benzidine Yellow, Pigment Yellow, India First Orange, Irgasin Red, Balanitoaniline Red, Toluidine Red, Carmine FB, Pigment Orange R, Lake Red 2G, Rhodamine FB, Rhodamine B Lake, Methyl Violet B Lakes, phthalocyanine blue, pigment blue, brilliant green, phthalocyanine green, oil yellow GG, Kayaset YG, orazol brown B, oil pink OP, and other pigments or dyes) usually in an amount of 5 to 10% by weight and magnetic powder (iron, Compounds such as cobalt, nickel, hematite, and ferrite) are usually used in an amount of 0 to 50% by weight. Furthermore, various additives [charge adjusting agent (Nigrosine dye, triphenylmethane derivative, quaternary ammonium salt compound, polymer containing polymerizable unit having quaternary ammonium base as a constituent unit, azo dye compound, salicylic acid metal complex , A copolymer containing, as constituent units, a polymerizable monomer having an aromatic ring substituted with an electron-withdrawing group (such as a nitro group or a perfluoroalkyl group) and a polymerizable monomer having a sulfo group, and a lubricant. (Such as polytetrafluoroethylene, low molecular weight polyolefin, fatty acid, or a metal salt or amide thereof). The amount of these additives is usually 0 based on the weight of the toner.
-10% by weight. The toner for developing a positive charge image is dry-blended, melt-kneaded, then coarsely pulverized, and finally finely pulverized using a jet pulverizer or the like to obtain fine particles having a particle size of 5 to 20 μm.

The toner for developing an electrostatic image is mixed with carrier particles such as iron powder, glass beads, nickel powder and ferrite, if necessary, and used as a developer for an electric latent image. A fluidity improver (hydrophobic colloidal silica fine powder or the like) can also be used to improve the fluidity of the powder. In addition, instead of the carrier particles, friction with a member such as a charging blade can be performed to form an electric latent image. The electrostatic image developing toner of the present invention is fixed on a support (paper, polyester film, or the like) by a copying machine, a printer, or the like to form a recording material. As a method for fixing to a support, a known hot roll fixing method, flash fixing method, or the like can be applied.

[0022]

The present invention will be further described with reference to the following examples, but the present invention is not limited to these examples. Hereinafter, "part" indicates "part by weight". The methods for measuring the properties of the resins obtained in Examples and Comparative Examples are described below. (Measurement method) Acid value A method specified in JIS K0070. However, when the sample does not dissolve, a solvent such as dioxane or tetrahydrofuran is used as the solvent. A sample after kneading at 120 ° C. for 30 minutes using a Lab Plastmill (manufactured by Toyo Seiki Seisakusho) is used as a sample. Glass transition temperature (Tg) Method specified in ASTM D3418-82 (DSC
Law). Molecular weight Gel permeation chromatography (GP
Measured in C). Labo Plastomill (Toyo Seiki Seisakusho)
The sample after kneading at 120 ° C. for 30 minutes is used as a sample. The conditions for measuring the molecular weight by GPC are as follows. Apparatus: HLC-802A manufactured by Toyo Soda Column: Column TSK gel GMH62
This (manufactured by Toyo Soda) Measurement temperature: 25 ° C. Sample solution: 0.5% by weight THF solution Solution injection amount: 200 μl Detector: Refractive index detector The molecular weight calibration curve was prepared using standard polystyrene. With a softening point flow tester (CFT-500, manufactured by Shimadzu Corporation)
Using a nozzle with a diameter of 1.0 mm × length of 1.0 mm, 10
kgf / cm2, measured at a heating rate of 5 ° C./min, 1.5 g
The temperature at which one half of the sample has flowed out is determined.

EXAMPLE 1 210 parts of terephthalic acid, 66 parts of adduct of bisphenol A with 2 mol of PO, and 3 mol of PO of bisphenol with a stirrer equipped with a thermometer, a torque detector, a condenser and a nitrogen inlet tube. 340 parts of adduct, bisphenol A
Was added, 95 parts of an adduct of 2 mol of EO, 45 parts of a adduct of 4.5 mol PO of a phenol novolak resin (number of nuclei: about 4.4) and 2 parts of dibutyltin oxide were subjected to a polyesterification reaction at 220 ° C. The acid value was measured at the point when the reaction product became transparent, and was found to be 12. Further Epicoat 1
After adding 8 parts of 54 (manufactured by Yuka Shell Epoxy Co.), the reaction was allowed to proceed under reduced pressure at the same temperature. When the acid value reached 3, the reaction was stopped, and the reaction product was taken out. The resin of the present invention (TB-1) I got (TB-1) has a Tg of 56 ° C. and a number average molecular weight of 400.
And a softening point of 138 ° C.

Example 2 In the same reactor as in Example 1, 205 parts of terephthalic acid, 190 parts of a 2-mol adduct of bisphenol A, 60 parts of a 3-mol adduct of bisphenol A, bisphenol A
250 parts of an EO 2 mol adduct, 60 parts of a 5.5 mol PO adduct of a phenol novolak resin (number of nuclei: about 5.5),
And 2 parts of dibutyltin oxide were added to carry out a polyesterification reaction at 220 ° C. The reaction proceeded under reduced pressure when the reaction product became transparent, and when the acid value was 9, EOCN was used.
After adding 7 parts of -1020 (manufactured by Nippon Kayaku Co., Ltd.), the reaction was further proceeded under reduced pressure. The reaction was stopped when the torque of the stirrer showed a predetermined value, to obtain the resin (TB-2) of the present invention.
Tg of (TB-2) is 61 ° C, number average molecular weight is 3500,
The acid value was 4, and the softening point was 135 ° C.

Example 3 In the same reactor as in Example 1, 260 parts of terephthalic acid, 290 parts of a 2-mol adduct of bisphenol A, 160 parts of a 3-mol adduct of bisphenol A, 120 parts of a 2-mol adduct of bisphenol A were added. 5.5 mol PO adduct of phenol novolak resin (nucleus number: about 5.5) 60
Parts and 2 parts of dibutyltin oxide
The polyesterification reaction was carried out at ℃. The reaction proceeds under reduced pressure when the reaction product becomes transparent. At the time when the acid value is 9, 14 parts of Epicron N-740 (manufactured by Dainippon Ink and Chemicals, Inc.) are added, and the reaction is further performed under reduced pressure. Was. The reaction was stopped when the torque of the stirrer showed a predetermined value to obtain the resin (TB-3) of the present invention. (TB-3) had a Tg of 64 ° C, a number average molecular weight of 4,500, an acid value of 6, a TG1 of 157 ° C, and a Tη of
Was 112 ° C.

Example 4 In the same reactor as in Example 1, 220 parts of terephthalic acid, 95 parts of a 3 mol PO3 adduct of bisphenol A, 680 parts of an adduct of 2 mol of EO of bisphenol A, and a phenol novolak resin (number of nuclei: about 5. 5.5) 5.5 mol EO adduct 4
0 parts and 2 parts of dibutyltin oxide
The polyesterification reaction was performed at 0 ° C. When the reaction became transparent, 15 parts of Epicron N-670 (manufactured by Dainippon Ink and Chemicals, Inc.) was added, and the reaction was further proceeded under reduced pressure. The reaction was stopped when the torque of the stirrer showed a predetermined value, to obtain the resin (TB-4) of the present invention. (TB-4) has a Tg of 60 ° C., a number average molecular weight of 4,100, an acid value of 14, and a TG of
1 was 159 ° C and Tη was 114 ° C.

Example 5 In the same reactor as in Example 1, 350 parts of terephthalic acid, 50 parts of isophthalic acid, 50 parts of dimethyl terephthalate, 550 parts of a 2-mol adduct of bisphenol A, 270 parts of a 3-mol adduct of bisphenol A, 190 parts of an adduct of 2 moles of EO of bisphenol A and 5.5 moles of EO adduct of phenol novolak resin (number of nuclei: about 5.5)
Parts and 2 parts of dibutyltin oxide
The polyesterification reaction was carried out at ℃. The reaction proceeds under reduced pressure when the reaction product becomes transparent, and when the acid value is 7, 23 parts of Epicron N-740 (manufactured by Dainippon Ink and Chemicals, Inc.) are added, and the reaction is further performed under reduced pressure. Was. The reaction was stopped when the torque of the stirrer showed a predetermined value, to obtain the resin (TB-5) of the present invention. (TB-5) has a Tg of 58 ° C, a number average molecular weight of 3,500, an acid value of 3, TG1 of 154 ° C, and Tη
Was 113 ° C.

COMPARATIVE EXAMPLE 1 In the same reactor as in Example 1, 260 parts of terephthalic acid, 260 parts of a 2-mol adduct of bisphenol A, 150 parts of a 3-mol adduct of bisphenol A, 125 parts of a 2-mol adduct of bisphenol A with EO, 5.5 mol PO adduct of phenol novolak resin (nuclear number about 5.5) 80
Parts and 2 parts of dibutyltin oxide
The polyesterification reaction was carried out at ℃. The reaction was proceeded under reduced pressure when the reaction product became transparent, and stopped when the torque of the stirrer showed a predetermined value, and the polyester resin (TR
-1) was obtained. (TR-1) had a Tg of 59 ° C, a number average molecular weight of 4000, an acid value of 10, and a softening point of 105 ° C.

Comparative Example 2 In a reaction apparatus similar to that in Example 1, 75 parts of terephthalic acid, 60 parts of dodecenylsuccinic anhydride, and PO2 of bisphenol A were added.
280 parts of a molar adduct, 130 parts of an EO 2 molar adduct of bisphenol A, 43 parts of trimellitic anhydride, and 2 parts of dibutyltin oxide were charged and subjected to a polyesterification reaction at 230 ° C. The reaction was proceeded under reduced pressure when the reaction product became transparent, and stopped when the torque of the stirrer showed a predetermined value, to obtain a polyester resin (TR-1).
Tg of (TR-1) is 55 ° C., number average molecular weight is 3800,
The acid value was 4, and the softening point was 138 ° C.

Comparative Example 3 75 parts of terephthalic acid, 60 parts of dodecenyl succinic anhydride, and PO2 of bisphenol A were placed in the same reactor as in Example 1.
280 parts of a molar adduct, 130 parts of an EO 2 molar adduct of bisphenol A, 43 parts of trimellitic anhydride, and 2 parts of dibutyltin oxide were charged and subjected to a polyesterification reaction at 230 ° C. The reaction was proceeded under reduced pressure when the reaction product became transparent, and when the acid value was 8, Epicron N-740 was used.
After adding 10 parts (manufactured by Dainippon Ink and Chemicals, Inc.), the reaction was further promoted under reduced pressure. The reaction was stopped when the torque of the stirrer showed a predetermined value, to obtain a comparative resin (TR-3). (TR-3) has a Tg of 56 ° C. and a number average molecular weight of 370.
0, acid value 4, and softening point 140 ° C.

COMPARATIVE EXAMPLE 4 250 parts of terephthalic acid, 230 parts of an adduct of 2 mol of PO of bisphenol A, 170 parts of an adduct of 3 mol of PO of bisphenol A, 180 parts of an adduct of 2 mol of EO of bisphenol A were placed in the same reactor as in Example 1. 50 parts of trimethylolpropane and 2 parts of dibutyltin oxide were added to carry out a polyesterification reaction at 230 ° C. The reaction was proceeded under reduced pressure when the reaction product became transparent, and when the acid value was 8, Epicron N-740 (manufactured by Dainippon Ink and Chemicals, Inc.)
After adding 14 parts, the reaction was further proceeded under reduced pressure. The reaction was stopped when the torque of the stirrer showed a predetermined value, and a comparative resin (TR-4) was obtained. Tg of (TR-4) is 58
° C, the number average molecular weight was 4,500, the acid value was 5, and the softening point was 140 ° C.

Comparative Example 5 In a reactor similar to that in Example 1, 210 parts of terephthalic acid, 50 parts of a 2-mol adduct of bisphenol A, 100 parts of a 3-mol adduct of bisphenol A, bisphenol A
350 parts of an EO 2 mol adduct of the above, 60 parts of a 5.5 mol EO adduct of a phenol novolak resin (number of nuclei: about 5.5),
And 2 parts of dibutyltin oxide were added to carry out a polyesterification reaction at 230 ° C. The reaction proceeded under reduced pressure from the point when the reaction product became transparent, and stopped when the torque of the stirrer showed a predetermined value, and the polyester resin (TR-
5) was obtained. (TR-5) had a Tg of 57 ° C, a number average molecular weight of 3,900, an acid value of 3, and a softening point of 141 ° C.

Use Examples 1 to 5 88 parts of each of the resins (TB-1) to (TB-5) of Examples 1 to 5 and carbon black (MA1 manufactured by Mitsubishi Kasei Co., Ltd.)
00) 7 parts, low molecular weight polyethylene (Sunwax 15
1-P, 5 parts by Sanyo Chemical Industry Co., Ltd.) and a charge control agent (Spiron Black TRH by Hodogaya Chemical Industry Co., Ltd.)
After the two parts are uniformly mixed, the mixture is kneaded with a Labo Plastomill at an internal temperature of 120 ° C., and the cooled product is finely pulverized with a jet mill and classified with a dispersion separator, and the toner compositions (T1) to (T5) having an average particle diameter of 9 μm I got Table 1 shows the evaluation results.

Comparative Use Examples 1 to 5 Resins (TR-1) to (TR-5) of Comparative Examples 1 to 5
8 parts, carbon black (MA10 manufactured by Mitsubishi Kasei Corporation)
0) 7 parts, low molecular weight polyethylene (Sunwax 151)
-P, 5 parts by Sanyo Chemical Industry Co., Ltd.) and a charge control agent (Spiron Black TRH by Hodogaya Chemical Industry Co., Ltd.)
After uniformly mixing the two parts, the mixture is kneaded with a Labo Plastomill at an internal temperature of 120 ° C., and the cooled product is finely pulverized with a jet mill and classified with a dispersion separator, and toner compositions (RT1) to (RT5) having an average particle diameter of 9 μm. I got Table 1 shows the evaluation results.
Shown in

[0035]

[Table 1] Evaluation results --- --- --- --- --- --- --- --- --- --- --- --- --- --- Toner resin Hot offset (° C.) (° C.) ----------------------------------------------------------------------------------------------------------------------------------------- Example of use (T1) (TB1) 185 130 (T2 ) (TB2) 190 130 (T3) (TB3) 190 135 (T4) (TB4) 195 135 (T5) (TB5) 185 130 ------------------------------------ -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- RT5) (TR5) 170 145 -------------------------- ------------------

(Evaluation Method) Preparation of Developer One part of the toner composition was mixed with 24 parts of a silicone resin-coated ferrite carrier (FL961-150, manufactured by Powder Tech) for electrostatic image development to prepare a developer. . Measurement of Hot Offset Occurrence Temperature A developer was prepared as described above, and a commercially available copying machine (B
D-7720) to transfer a toner image onto paper, and transfer the transferred toner on paper to a commercial copying machine (SF8 manufactured by Sharp Corporation).
The fixing section of 400 A) was modified, and the temperature at which hot offset occurred at a speed of 35 sheets / minute of A4 paper was measured. Measurement of low-temperature fixability A developer was prepared as described above, and a commercially available copying machine (B
D-7720) to transfer a toner image onto paper, and transfer the transferred toner on paper to a commercial copying machine (SF8 manufactured by Sharp Corporation).
The fixing section of 400 A) was modified, and the temperature at which the rub fixing rate was 80% was measured at a speed of 35 sheets / minute of A4 paper. The rubbing fixation rate is defined as the residual image density of the solid portion when a black solid portion having an image density of 1.2 is rubbed in five reciprocations with a Gakushin-type fastness tester (friction portion = paper). It was calculated from: Residual rate (%) = (image density after rubbing / image density before rubbing) × 100

[0037]

The toner binder for developing an electrostatic image of the present invention has the following effects. 1. Excellent offset resistance. 2. Excellent low-temperature fixability. 3. It is possible to obtain a toner which is excellent in environmental dependency and has a small change in the charge amount even under various environments. 4. High reactivity during binder production and easy to control.

Claims (2)

(57) [Claims] 1. A carboxylic acid (A) and a diol (B)
And a crosslinked polyester resin of a novolak type resin with an oxyalkylene ether (C) and at least one epoxy compound (D) selected from the group consisting of a novolak type epoxy resin and an epi-bis type epoxy resin. A toner binder for developing an electrostatic charge image, comprising a resin having a THF insoluble content of 2 to 60% by weight. ^{2. The} temperature (TG1) at which the storage elastic modulus at a measurement frequency of 20 Hz becomes 6 × 10 ⁴ dyne / cm ² is 110 ° C.
And a temperature (Tη) at which the viscosity at a measurement frequency of 20 Hz becomes 1 × 10 ⁴ poise is 90 ° C. to 16 ° C.
The toner binder for developing an electrostatic image according to claim 1, wherein the temperature is 0 ° C.