JP3214080B2 - Electrostatic toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to electrophotography, electrostatic recording,
The present invention relates to an electrostatic charge developing toner used for developing an electrostatic image in electrostatic printing or the like.

[0002]

2. Description of the Related Art In an electrophotographic method, an electrostatic latent image is usually formed on a latent electrostatic image bearing member made of a photoconductive photoreceptor by charging and exposing the same, and then the electrostatic latent image is formed in a binder resin. Is developed by a toner composition containing a colorant, and the obtained toner image is transferred and fixed to a support such as transfer paper to form a visible image.

[0003] As a toner composition for obtaining such a visible image, polystyrene, styrene- (meth) acrylate copolymer, polystyrene, styrene- (meth) acrylate copolymer, and the like are generally used as the binder resin for the toner. Styrene-
Butadiene copolymer, polyester resin, epoxy resin, butyral resin, xylene resin, coumarone indene resin, etc. are listed, but in the current copier, to lower the fixing temperature, and to improve the fixing strength, toner It is desired that the resin viscosity at the time of fixing be lower than the resin viscosity of a conventional toner for a general copying machine, and the glass transition temperature of the binder resin by differential thermal analysis be 50 ° C. or higher, More preferably, 55 ° C. or more is appropriate. If the glass transition temperature is too low, the toner tends to block. The glass transition temperature represents an endothermic peak temperature in differential thermal analysis. The melt viscosity of the binder resin by a flow tester method is 1 × 10 ⁴ to 1 × 10 ⁶ poise at 100 ° C.
Preferably, 3 × 10 ^{4 to} 5 × 10 ⁵ poise is suitable.
If the melt viscosity is too low, the offset resistance becomes poor, and if it is too high, good fixing strength cannot be obtained. However, melt viscosity was measured by Shimadzu Flow Tester CFT-
Nozzle diameter 1 mm, load 30 kg, heating rate 3
It is a value at 100 ° C. measured under the condition of ° C./min.

As a colorant in a toner composition, a colorant in which a black colorant such as carbon black is dispersed in a binder resin is often used.
Color toners in which red or yellow pigments are dispersed in a binder have also been used.

[0005]

However, with the advance of electrophotographic technology, the speeding up and colorization of the system have been progressing, and the toner using the binder resin of the prior art has sufficient fixability and heat-resistant storage stability. , Vivid color reproduction,
It is difficult to maintain the compatibility of the color transmittance of the OHP film, and it is also difficult to maintain a stable visible image. Examples of the binder resin that solves these problems include a polyester resin and an epoxy resin. That is, styrene resin, styrene-acrylic resin, styrene-
In the case of a butadiene-based resin and others, when the above-mentioned melt viscosity is used, the glass transition temperature becomes too low, and the toner blocking property is lowered, so that it cannot be put to practical use. However, these polyester resins and epoxy resins have a large number of hydrophilic groups such as carboxyl groups and hydroxyl groups in the molecule, and therefore, these resins have higher hygroscopicity than polystyrene and styrene-acrylic copolymer resins. It tends to be high, and as a result, it has a drawback that the charge amount with respect to environmental changes is liable to change. In some cases, the melt viscosity may increase in the hot melt kneading step of toner formation, or a chemical effect on the photoconductor may occur.

An object of the present invention is to provide a novel resin system satisfying these characteristics.

[0007]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have reached the development of a novel resin system having a low melt viscosity and a high glass transition temperature.

That is, the present invention is to solve the above-mentioned problems.
And a general formula (1) as a binder resin

[0009]

Embedded image

[0010] The present invention provides a toner for developing an electrostatic charge image , characterized by containing a resin represented by the formula: wherein n represents 1 to 10.

Next, the present invention will be described in detail.

The compound represented by the general formula ( 1 ) used in the present invention
That tree butter is prepared from epichlorohydrin and bisphenol A. The manufacturing method at this time is an advanced method generally used for manufacturing an epoxy resin. This method
As a first step reaction, epichlorohydrin and bisphenol A are reacted in a usual manner to produce a low molecular weight epoxy resin, and as a second step reaction, bisphenol A and a polymerization catalyst are further added to the low molecular weight epoxy resin, Performing heat polymerization. In this method, the onset Akira
In order to obtain the resin of the general formula (1) in the above, the amount of the phenolic hydroxyl group of the bisphenol A used in the second-stage reaction is calculated based on 1 equivalent of the epoxy equivalent of the low-molecular-weight epoxy resin obtained in the first-stage reaction. , It is necessary to use one equivalent or more. If the amount of this phenolic hydroxyl group is 1
If it is less than the equivalent, the terminal group of the obtained resin becomes a glycidyl ether group, and bisphenol A is added to the target terminal.
Cannot be obtained. On the other hand, when the amount of the phenolic hydroxyl group is too large, the molecular weight of the obtained reaction product becomes small, and thus the fixing properties of the obtained toner tend to decrease, which is not preferable. Therefore, the amount of the phenolic hydroxyl group of bisphenol A used in the second-stage reaction is preferably in the range of usually 1.01 to 3.5 equivalents relative to 1 equivalent of the epoxy equivalent of the low molecular weight epoxy resin. Examples of the polymerization catalyst in the second-stage reaction include catalysts used in ordinary epoxy resin polymerization, for example, alkali metal hydroxides and salts thereof, tertiary amines, quaternary ammonium salts, imidazoles, and phosphine. , Phosphonium salts or mixtures thereof.

The toner for developing an electrostatic charge of the present invention only needs to contain the above resin system as a binder resin, and the use of a colorant, a release agent, a charge control agent, a magnetic material, and other additives is limited. It is not what you receive.

That is, as a coloring agent, carbon black is generally used for a black toner.
A toner that is blackened by appropriately selecting and mixing a yellow dye, a red dye, an orange dye, a brown dye, a purple dye, a blue dye, a green dye, and the like is used. Sometimes. As these dyes, for example, azo dyes, quinoline dyes, isoindoline dyes, tetrachloro-isoindolinone dyes, imidazolone dyes, anthraquinone dyes, xanthene dyes, Perylene dyes, quinacridone dyes,
And phthalocyanine-based dyes and pigments.

Further, it can be sufficiently used for a color toner, and the colorant component in that case is not limited.
Examples of the coloring agent include, for example, azo dye, anthraquinone dye, phthalocyanine dye, indigo dye, thioindigo dye, diphenylmethane dye, triphenylmethane dye, polymethine dye, azomethine dye, xanthene dye, acridine dye, quinone imine dye, cyanine dye, quinoline Dye, nitro dye, naphthoquinone dye, perylene dye, nitro pigment, nitroso pigment, acid dye lake pigment, basic dye lake pigment, mordant dye lake pigment,
Soluble azo pigment, insoluble azo pigment, azo complex salt pigment, condensed azo pigment, benzimidazolone pigment, phthalocyanine pigment, anthraquinone pigment, thioindigo pigment, perylene pigment, perinone pigment, quinacridone pigment, dioxane pigment, quinophthalone pigment, isoindolinone pigment, And metal complex pigments. The content of the colorant component is 1 to 100 parts by weight of the binder resin constituting the toner.
A range of from 10 to 10 parts by weight is preferred. If the amount is less than 1 part by weight, the hiding power tends to be insufficient, and sufficient color density tends not to be obtained.
On the other hand, if the amount exceeds 10 parts by weight, undesired effects on the fixing characteristics and charging characteristics and effects such as impairment of color saturation tend to appear, which is not preferable.

As the release agent, low molecular weight polyethylene,
Examples include waxes such as low molecular weight polypropylene, liquid paraffin, fatty acid esters, fatty acid amides, and ethylene-vinyl acetate copolymers.

Various charge controlling agents can be used in the toner of the present invention. Typical examples thereof include a nigrosine dye, a triphenylmethane dye, a quaternary ammonium salt complex and its derivatives, and various metals. Examples include complex azo dyes, salicylic acid metal complexes, sulfonylamine of copper phthalocyanine, and chlorinated paraffin.

Examples of the magnetic material include metal powders such as iron, manganese, nickel, and cobalt, alloys, fine particles of oxides, iron alloys such as ferrite and magnetite, and other magnetic materials.

Further, the toner of the present invention may be provided with a fine powder of an oxide such as silicon, titanium, aluminum or cerium, or a metal salt of a fatty acid metal, which has been subjected to a hydrophobic treatment for the purpose of improving the fluidity and cleaning properties of the toner. Fine powder or the like can be added.

To produce a toner, a binder resin,
The colorant and the charge control agent are well mixed in advance by a ball mill or the like, then sufficiently melt-kneaded in various kneaders, cooled, and finely pulverized by a jet mill or the like, and classified to a required particle size. If necessary, a fluidity improver or the like is added and mixed.

[0021]

The present invention will be described in more detail with reference to the following examples. In the examples, "parts" means "parts by weight".

(Resin Production Example 1) Epichlorohydrin 450 was placed in a four-necked flask equipped with a thermometer, a stirrer and a heater.
And heat it under a nitrogen stream to reduce the temperature inside the flask to 7
0 ° C., and subsequently 0.48 part of an aqueous sodium hydroxide solution as a catalyst was added.
The temperature was increased to
After adding 5.16 parts and completely dissolving, the mixture was reacted in a nitrogen atmosphere for 5 hours while maintaining the temperature at 160 ° C. to obtain a reaction product having bisphenol A at the terminal. The weight average molecular weight of this resin is 1,300, Tg is 70 ° C.,
The melt viscosity was 3 × 10 ⁴ poise.

(Example 1) <Preparation of Toner> 93 parts of the resin obtained in Production Example 1 and carbon black "Elftex 8" (E
lftex 8; manufactured by Cabot Corporation) and 5 parts of "Bontron E-84" (Orient Chemical Industries, Ltd.) as a charge control agent.
2 parts were melt-kneaded, cooled, pulverized finely with a jet mill, classified, and classified into a toner having an average particle size of 11 μm (hereinafter referred to as “hereinafter”).
Expressed as "Toner (1)". ) Was prepared.

<Preparation of developer> 4 parts of toner (1) and "Ferrite carrier F-150" (Powdertech Co., Ltd.)
Was mixed by friction to prepare a developer.

<Measurement of Charge Amount> The prepared developer was subjected to high temperature and high humidity (40 ° C., 90% RH), normal temperature and normal humidity (20 ° C., 50%).
% RH) and low temperature and low humidity (10 ° C., 20% RH) for 1 hour, and the charge amount was measured immediately after that. The charge amount fluctuation width accompanying the environmental change was calculated and evaluated. The results are shown in Table 1. In the table, HH indicates a high-temperature and high-humidity environmental condition, MM indicates a normal-temperature and normal-quality environmental condition, LL indicates a charge amount under a low-temperature and low-humidity environmental condition, and an environmental difference indicates a value obtained by subtracting HH from LL.

<Evaluation of storage stability> Toner (1) 5 obtained
g was weighed into a 50 cm ³ glass bottle, left in an atmosphere adjusted to 50 ° C. for 24 hours, and the degree of aggregation was evaluated. The results are shown in Table 1.

<Evaluation of Toner Strength> With respect to a printed material developed with a developer prepared using the toner (1), the strength of the fused toner fixed against bending was evaluated. The results are shown in Table 1.

(Resin Production Example 2)
A reaction product was obtained in the same manner as in Resin Production Example 1, except that 0.65 part of an aqueous sodium hydroxide solution and 675 parts of bisphenol A were used. The weight average molecular weight of this resin is
1,800, Tg: 78 ° C., melt viscosity: 1 × 10 ⁵
Poise.

(Example 2) <Preparation of toner> Example 1 was repeated except that 93 parts of the resin obtained in Resin Production Example 2 was used in place of the resin obtained in Resin Production Example 1. In the same manner as described above, the average particle size is 11
μm toner (hereinafter, referred to as “toner (2)”) was produced.

<Preparation of Developer> A developer was prepared by frictionally mixing 4 parts of the toner (2) and 96 parts of “Ferrite Carrier F-150”.

<Measurement of Charge Amount> The amount of charge of the prepared developer was measured in the same manner as in Example 1, and the fluctuation range of the charge amount due to environmental changes was calculated and evaluated. The results are shown in Table 1.

<Evaluation of Storage Property> The obtained toner (2) was evaluated for the degree of aggregation in the same manner as in Example 1. The results are shown in Table 1.

<Evaluation of Toner Strength> With respect to the printed matter developed with the developer prepared using the toner (2), the strength of the fused toner fixed against bending was evaluated. The results are shown in Table 1.

(Resin Production Example 3)
A reaction product was obtained in the same manner as in Resin Production Example 1 except that 0.79 part of an aqueous sodium hydroxide solution and 810 parts of bisphenol A were used. The weight average molecular weight of this resin is
2,200, Tg: 82 ° C., melt viscosity: 5 × 10 ⁵
Poise.

(Example 3) <Preparation of toner> Example 1 was repeated except that 93 parts of the resin obtained in Resin Production Example 2 was used instead of the resin obtained in Resin Production Example 1. In the same manner as described above, the average particle size is 11
μm toner (hereinafter, referred to as “toner (3)”) was produced.

<Preparation of Developer> A developer was prepared by frictionally mixing 4 parts of the toner (3) and 96 parts of “Ferrite Carrier F-150”.

<Measurement of Charge Amount> The charge amount of the prepared developer was measured in the same manner as in Example 1, and the fluctuation width of the charge amount due to the environmental change was calculated and evaluated. The results are shown in Table 1.

<Evaluation of Storage Property> The obtained toner (3) was evaluated for the degree of aggregation in the same manner as in Example 1. The results are shown in Table 1.

<Evaluation of Toner Strength> With respect to the printed matter developed with the developer prepared using the toner (3), the strength against bending of the melt-fixed toner was evaluated. The results are shown in Table 1.

Example 4 <Preparation of Toner> 95 parts of the resin obtained in Resin Production Example 1 and a copper phthalocyanine pigment “KET BL” as a colorant were used.
3 parts of "UE 111" (manufactured by Dainippon Ink and Chemicals, Inc.) and 2 parts of "Bontron E-84" as a charge controlling agent are melt-kneaded, cooled, finely pulverized with a jet mill, classified and averaged in particle size. An 11 μm toner (hereinafter, referred to as “toner (4)”) was produced.

<Preparation of Developer> A developer was prepared by frictionally mixing 4 parts of the toner (4) and 96 parts of “Ferrite Carrier F-150”.

<Measurement of Charge Amount> The amount of charge of the prepared developer was measured in the same manner as in Example 1, and the fluctuation width of the charge amount due to environmental changes was calculated and evaluated. The results are shown in Table 1.

<Evaluation of Storage Property> The obtained toner (4) was evaluated for the degree of aggregation in the same manner as in Example 1. The results are shown in Table 1.

<Evaluation of Toner Strength> With respect to a printed material developed with a developer prepared using the toner (4), the strength against bending of the melt-fixed toner was evaluated. The results are shown in Table 1.

Comparative Example 1 <Preparation of Toner> Epoxy resin “Epiclon 405”
0 ”(manufactured by Dainippon Ink and Chemicals, Inc., Tg: 65 ° C., weight average molecular weight: 4,500) and 93 parts of the same colorant and charge control agent as in Example 1 were used in the same manner as in Example 1. A toner (hereinafter, referred to as “toner (5)”) was produced.

<Preparation of Developer> A developer was prepared by frictionally mixing 4 parts of the toner (5) and 96 parts of “Ferrite Carrier F-150”.

<Measurement of Charge Amount> The amount of charge of the prepared developer was measured in the same manner as in Example 1, and the fluctuation range of the charge amount due to environmental changes was calculated and evaluated. The results are shown in Table 1.

<Evaluation of Storage Property> The obtained toner (5) was evaluated for the degree of aggregation in the same manner as in Example 1. The results are shown in Table 1.

<Evaluation of Toner Strength> The printed material developed with the developer prepared by using the toner (5) was evaluated for the strength against bending of the melt-fixed toner. The results are shown in Table 1.

Comparative Example 2 <Preparation of Toner> In Example 1, 64 parts of 2,2′-bis [p- (2-hydroxyethoxy) -phenyl] propane was used in place of the resin of Resin Production Example 1, Isophthalic acid 1
6 parts, terephthalic acid 16 parts, maleic anhydride 0.6 part,
Polyester resin obtained by reacting 0.06 parts of dibutyltin oxide (melt viscosity: 5 × 10 ⁴ poise, Tg:
A toner (hereinafter, referred to as “toner (6)”) was prepared in the same manner as in Example 1, except that 93 parts of a toner (59 ° C., weight average molecular weight: 10,000) was used.

<Preparation of Developer> A developer was prepared by frictionally mixing 4 parts of the toner (6) and 96 parts of “Ferrite Carrier F-150”.

<Measurement of Charge Amount> The amount of charge of the prepared developer was measured in the same manner as in Example 1, and the fluctuation width of the charge amount due to environmental changes was calculated and evaluated. The results are shown in Table 1.

<Evaluation of Storage Property> The obtained toner (6) was evaluated for the degree of aggregation in the same manner as in Example 1. The results are shown in Table 1.

<Evaluation of Toner Strength> With respect to a printed material developed with a developer prepared using the toner (6), the strength against bending of the melt-fixed toner was evaluated. The results are shown in Table 1.

Comparative Example 3 <Preparation of Toner> In Example 1, a styrene / acrylic resin “Hymer SB” was used in place of the resin of Resin Production Example 1.
M-100 "(manufactured by Sanyo Kasei Kogyo Co., Ltd., Tg: 54 ° C, weight average molecular weight: 13,000)" except that 93 parts of toner were used in the same manner as in Example 1 (hereinafter referred to as "toner (7) ").

<Preparation of Developer> A developer was prepared by frictionally mixing 4 parts of the toner (7) and 96 parts of “Ferrite Carrier F-150”.

<Measurement of Charge Amount> The amount of charge of the prepared developer was measured in the same manner as in Example 1, and the fluctuation range of the charge amount accompanying the environmental change was calculated and evaluated. The results are shown in Table 1.

<Evaluation of Storage Property> The obtained toner (7) was evaluated for the degree of aggregation in the same manner as in Example 1. The results are shown in Table 1.

<Evaluation of Toner Strength> The printed matter developed with the developer prepared using the toner (7) was evaluated for the bending strength of the fused toner. The results are shown in Table 1.

[0060]

[Table 1]

[0061]

According to the toner using the resin system according to the present invention, the melt viscosity is low, the glass transition temperature is high,
Sufficient heat-resistant storage stability and sufficient fixing strength can be obtained.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-1-267562 (JP, A) JP-A-3-28856 (JP, A) JP-A-1-134466 (JP, A) JP-A-1- 173054 (JP, A) JP-A-1-236225 (JP, A) JP-A-2-882 (JP, A) JP-A-1-267558 (JP, A) JP-A-52-156632 (JP, A) JP-A-63-298252 (JP, A) JP-A-63-298253 (JP, A) JP-A-1-134370 (JP, A) JP-A-4-123065 (JP, A) (58) (Int.Cl. ⁷ , DB name) G03G 9/08

Claims (4)

(57) [Claims] 1. A binder resin having the general formula (1): ## STR1 ## (Wherein n represents 1 to 10). A toner for developing an electrostatic image, comprising a resin represented by the following formula: 2. The melt viscosity of the binder resin at 100 ° C. by a flow tester method is from 1 × 10 ⁴ to 1 × 1.
0 claim 1 toner according which is a ⁶ poise. 3. The melt viscosity of the binder resin at 100 ° C. by a flow tester method is 3 × 10 ^{4 to} 5 × 1.
0 ⁵ claim 1 toner according which is a poise. 4. A binder resin having a glass transition temperature of 7
4. The temperature is 0 to 82 [deg.] C.
The toner for developing electrostatic images according to any one of the above.