JPH0580585A - Electrostatic charge image developer composition - Google Patents

Abstract

(57) [Summary] (Modified) [Constitution] The diol component of the formula (1) is less than 10 mol% in all the constitutional components, and the diol component of the formula (2) is 10 mol% or more and less than 25 mol%. Copolycondensation of divalent carboxylic acid or acid anhydride thereof or lower alkyl ester thereof and trivalent or higher polyvalent carboxylic acid or acid anhydride thereof or lower alkyl ester thereof at 2.5 mol% or more and less than 15 mol% In the electrostatic image developer composition using the above polyester resin as the main component of the binder resin, 0.01 to 1.5 parts by weight of hydrophobic silica having a hydrophobicity of 80 or more is contained with respect to 100 parts by weight of the toner. .. (In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 7).
Is. ) (In the formula, n is an integer of 2 to 6.) [Effect] High fluidity and charge amount can be secured with a small amount of hydrophobic silica added, and black spots do not occur.

Description

Detailed Description of the Invention

[0001]

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

[0002]

2. Description of the Related Art It is known that the particle size of toner and the particle size distribution of toner are important factors in obtaining high resolution and high image quality in the development of an electrostatic image by electrophotography or the like. When the toner particle size is reduced, the smaller the particle size, the more grinding energy is required, which generally lowers the productivity and increases the cost. It is required to be the main component.

However, even if the pulverizability of the resin itself is improved to reduce the particle size of the toner, the surface area per unit weight of the toner is increased, so that the friction and aggregation of the toner particles are increased or the high humidity condition is applied. It has been pointed out that there is a problem that the fluidity is rather lowered, such as an increase in the amount of water adhering to the surface of the toner particles, which lowers the chargeability of the toner and lowers the developability due to the lowering of toner transportability. .. Further, it has been pointed out that if the particle size is simply reduced, the abundance of extremely small particles of 5 μm or less increases, and the particle size distribution becomes broad, resulting in a decrease in the uniformity of toner charging.

Therefore, in JP-A-54-72054 and JP-A-58-129437, the particle size distribution is also regulated, and the number% of 5 μm or less is reduced to improve the fluidity and the variation of the toner charge amount. Toners have been proposed. However, it is still insufficient to reduce the number% of 5 μm or less, and there is still room for improvement in fluidity and chargeability.

Further, in JP-A-2-284151, a toner characterized by containing a toner having an average particle diameter of 4 to 6 μm containing 60% by number or more of toner particles having a particle diameter of 5 μm or less and an inorganic compound fine powder. Is proposed. Although it is possible to obtain a sharp image quality with such a toner, it has been reported that it is necessary to increase the amount of the inorganic compound fine powder added because the number% of particles having a particle size of 5 μm or less is large.

Various types of fine particles of such inorganic compounds have been known so far, but in general, fine particles of silicon dioxide (silica) are added and mixed as a surface treatment agent to toner powder. ing. Since fine silica powder is hydrophilic as it is, it is known that it absorbs moisture in the air under high temperature and high humidity to cause deterioration of fluidity and aggregation of toner. For this reason, it has been proposed to use fine silica powder that has been subjected to a hydrophobic treatment (see JP-A-46-5782 and JP-A-48-47345). A dimethyl substitution product in which a methyl group of silane is bonded to silica by reacting chlorosilane is known (R-
972: manufactured by Nippon Aerosil Co., Ltd.).

However, although these fine silica powders are tentatively hydrophobized, the degree of hydrophobization cannot be said to be sufficient, and cohesiveness is recognized under high temperature and high humidity, and toner flow It has been pointed out that the hydrophobicity is lowered, and the degree of hydrophobization has been a problem. That is, for example, in the case of R-972, the ratio of the silanol groups of the hydrophilic silica to be hydrophobized is only 70 to 80%, and the remaining 20 to 30% of the silanol groups remains as it is without being substituted. Therefore, the hydrophobicity was only 40. Therefore, it has been pointed out that it is difficult for the toner to stably form a large number of visible images with good image quality over a long period of time by using such a fine powder of hydrophobic silica.

In recent years, in order to solve such a problem, the hydrophobicity index (that is, the degree of hydrophobicity) obtained by hydrophobizing with an organic silicon compound having a specific organic group is 50 or more, preferably. Is 65 to 65 parts by weight of hydrophobic silica fine powder relative to the toner powder.
In the case of adding by weight% and mixing, it is possible to stably form a visible image of good quality in forming a large number of visible images over a long period of time (Japanese Patent Laid-Open No. 59-81650).
Similarly, it has been proposed to add 0.01 to 20% by weight of hydrophobic silica fine powder that has been hydrophobized so that the degree of hydrophobicity is in the range of 30 to 80 (JP-A-59-23).
No. 1552).

These hydrophobizing treatments are carried out by using a conventionally known hydrophobizing method, and chemically treating with an organic silicon compound or the like which reacts with or physically adsorbs silica fine powder. Generally, a method is used in which silica fine powder produced by vapor phase oxidation of a silicon halogen compound is treated with a silane coupling agent, or is treated with a silane coupling agent and simultaneously treated with an organosilicon compound.

[0010]

However, what is conventionally known as a hydrophobic silica having a high degree of hydrophobicity is:
The degree of hydrophobicity is at most less than 80, and those disclosed in the above-mentioned publication (JP-A-59-231552) also have a degree of hydrophobicity up to 74. JP-A-59-81
In Japanese Patent Laid-Open No. 650, it is indicated that the one having a high degree of hydrophobicity is> 6.
Although it is described as 5, the upper limit is not clear, and the high degree of hydrophobicity disclosed in this publication is unknown. These hydrophobic silicas having a hydrophobicity in the range of at most about 80 are certainly improved in charge retention and fluidity as compared with conventional dimethyl-substituted compounds having a hydrophobicity of 40 to 42. Although observed, it is still insufficient under high temperature and high humidity.
This has been a hindrance to deterioration of charge retention and fluidity, and eventually to stable formation of a visible image of good quality.

The hydrophobized silica has an insufficient degree of hydrophobization and a large amount of unreacted silanol groups remains,
Alternatively, since the substituent that has reacted with the silanol group is a small atomic group as a whole, a stable hydrogen bond is formed by the other unreacted silanol group, the carboxyl group in the binder resin of the toner particles, and the moisture in the environment. As a result, the various problems described above occur under high temperature and high humidity. Therefore, whether or not the degree of hydrophobization is sufficient depends on how much hydrophilic group the binder resin has.

Binder resins for toner are generally polystyrene, styrene-butadiene copolymer, styrene.
Styrene copolymers such as acrylic copolymers, polyethylene, ethylene copolymers such as ethylene / vinyl acetate copolymers, various resins such as poly (meth) acrylic acid ester, polyester resin, epoxy resin, polyamide resin Is used. Of these resins, normal styrene
For a highly hydrophobic substance such as acrylic resin, the hydrophobicity of hydrophobic silica may not be required to be so high, but in particular, polyester resin is particularly suitable for polycondensation of alcohol and carboxylic acid. The resulting resin contains a large amount of a carboxyl group which is a hydrophilic group in the resin, which causes a decrease in the charge retention and fluidity of the toner by hydrogen bonding with water, It has been pointed out that the conventional degree of hydrophobicity is insufficient.

In particular, when the polyester resin is used as the main component of the binder resin and the toner has a small particle size in order to obtain the above-mentioned high resolution and high image quality, the surface area per unit weight of the toner is Increase, it becomes more susceptible to the moisture in the environment, and the fluidity decreases. Therefore, it is necessary to add a surface treatment agent such as hydrophobic silica fine powder to obtain sufficient fluidity. In such a case, in the conventional hydrophobic silica, it is necessary to increase the addition amount of the hydrophobic silica in order to secure the fluidity of the toner particles as described above. For example, according to the above-mentioned publication (Japanese Patent Laid-Open No. 59-81650), which has a hydrophobicity of 50 or more and which is conventionally considered to have a high degree of hydrophobicity, 0.01 to
The above-mentioned publication which has been subjected to a hydrophobizing treatment so as to exhibit a value in the range of 30 to 80 at 15% by weight (JP-A-59-231552).
Then, it is described that 0.01 to 20% is added.

However, it has been pointed out that when the amount of the hydrophobic silica added is increased, the liberated silica damages the surface of the photoconductor even though the fluidity can be secured, and black spots are generated around the silica. Here, the black spot is a kind of filming on the photoconductor,
It appears as black spots on the visible image. this is,
Since the particles of the hydrophobic silica are considerably hard, it is remarkable when the photoconductor has a relatively small hardness such as a selenium-tellurium-based material or an organic photoconductor, and further, it is considered to be relatively hard. Selenium, which is fragile against mechanical shock,
The same problem has occurred when using an arsenic-based substance.

Further, when a large amount of the hydrophobic silica is added, the moisture resistance of the hydrophobic silica is insufficient at the time of use under high temperature and high humidity, so that the fluidity of the toner tends to be lowered. Has been done. Therefore, it is desirable that the addition amount of the hydrophobic silica is as small as possible, and it is desirable to use the hydrophobic silica that can improve the charge retention and fluidity of the toner by adding such a small amount.

On the other hand, the hydrophobizing treatment of silica is conventionally carried out by vapor phase oxidation of a silicon halogen compound in a reactor heated to about 400 ° C. as described above. For example, oxyhydrogen of silicon tetrachloride gas is used. The following reaction has been carried out by a method utilizing a thermal decomposition oxidation reaction in a flame. SiCl ₄ + 2H ₂ + O ₂ → SiO ₂ + 4HCl However, since the removal of hydrogen chloride generated during the reaction is generally not easy, the pH of the obtained hydrophobic silica is as low as about 3 to 4 and the hydrophobic silica for toner equipment is used. It was also pointed out that the inner wall of the tank had "rust" during long-term use. That is, in the conventionally used hydrophobic silica, in addition to the problem of suitability of the degree of hydrophobicity and the problem of the addition amount, it was caused by hydrogen chloride generated by the treatment for increasing the degree of hydrophobicity. There has also been an urgent need to take measures against acidification of the hydrophobic silica fine powder.

The object of the present invention lies in this point, and in order to solve these various problems, development is carried out by using a predetermined polyester resin having excellent pulverizability and easily reducing the particle size as a binder resin for the toner. Agent, charge retention of toner,
An electrostatic charge image developer composition that does not show a decrease in fluidity, stably forms a visible image of good quality even when forming a large number of visible images for a long period, and does not show the generation of black spots. To provide.

[0018]

Means for Solving the Problems The inventors of the present invention have conducted various studies for the purpose of solving the above-mentioned problems, and as a result, they have been hydrophobized so that the degree of hydrophobization is 80 or more. It was found that by using the hydrophobic silica fine powder, an excellent visible image can be formed, such as no deterioration in charge retention property and fluidity of the toner, and particularly 6 to
The inventors have found that a toner having a small particle diameter of 10 μm can secure fluidity and environmental resistance that have not been achieved in the past, and have further researched to complete the present invention.

That is, the gist of the present invention is (a) the following equation (1)

[Chemical 6] (In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 7).
Is. ) The diol component represented by
When it is less than mol%, (b) the following formula (2)

[Chemical 7] (In the formula, n is an integer of 2 to 6), and 10% by mole or more and less than 25% by mole of all the constituent components, (C) a divalent carboxylic acid or an acid anhydride thereof, or The lower alkyl ester and (d) a polyvalent carboxylic acid having a valence of 3 or more, or an acid anhydride thereof or a lower alkyl ester thereof is contained in an amount of 2.5 mol% or more and less than 15 mol% in all constituents, and if necessary ( ) Equation (3)

[Chemical 8] (In the formula, R ′ is an alkylene group having 2 to 4 carbon atoms, and n is 2 to
It is an integer of 4. In the electrostatic charge image developer composition, a polyester resin obtained by copolycondensing a diol component represented by the formula (1) in an amount of 1.5 mol% or more and less than 10 mol% in all constituents is used as a main component of a binder resin. An electrostatic charge image developer composition comprising 0.01 to 1.5 parts by weight of hydrophobic silica having a hydrophobicity of 80 or more in a methanol titration test, relative to 100 parts by weight of a toner, and the above polyester. In an electrostatic charge image developer composition using a resin as a main component of a binder resin, a pH when 4 wt% of hydrophobic silica is dispersed in a water / methanol (1: 1) solution with respect to 100 parts by weight of a toner The present invention relates to an electrostatic charge image developer composition characterized by containing 0.01 to 1.5 parts by weight of hydrophobic silica having a ratio of 5.5 to 8.

The polyester portion in the resin used as the main component of the binder resin in the present invention is obtained by polycondensation of alcohol and carboxylic acid, or carboxylic acid ester or carboxylic acid anhydride. Examples of the diol component of (a) include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3.3) -2,2-bis (4
-Hydroxyphenyl) propane, polyoxyethylene
(2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -polyoxyethylene
Examples thereof include (2.0) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane.
The diol component (a) is used in an amount of less than 10 mol% in all the constituent components, but if it is 10 mol% or more, the negative chargeability of the polyester resin increases, and it becomes difficult to obtain a positively chargeable toner.

Examples of the diol component (b) include ethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol and 1,6-hexanediol. Among them, ethylene glycol, 1,3-propylene glycol and 1,4-butanediol are preferably used. The diol component (b) is used in an amount of 10 mol% or more and less than 25 mol% in all the constituent components, but if it is less than 10 mol%, the minimum fixing temperature of the toner becomes high, and if it is 25 mol% or more, the resin becomes crystalline. However, it is not preferable as described in JP-B-57-493. In some cases, other diols such as diethylene glycol, triethylene glycol, 1,2-propylene glycol, neopentyl glycol, 1,4-butene diol, bisphenol A, hydrogenated bisphenol A, and other divalent diols. Alcohol can be added.

Examples of the (c) carboxylic acid component in the present invention include maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, cyclohexanedicarboxylic acid, succinic acid. , Adipic acid, sebacic acid, azelaic acid, malonic acid, alkenyl succinic acid or alkyl succinic acid such as n-dodecenyl succinic acid, n-dodecyl succinic acid, anhydrides of these acids, lower alkyl esters and other divalent acids Mention may be made of carboxylic acids.
Of these, terephthalic acid or its lower alkyl ester is particularly preferable.

Further, (d) the trivalent or higher polyvalent carboxylic acid or its derivative in the present invention is a preferable component for improving the offset phenomenon, but when the amount is small, the effect is thin, and the polyester resin and the toner are pulverized. In the case where the properties are deteriorated and the number is large, it is difficult to control the reaction, it is difficult to obtain a polyester resin having stable performance, and unfavorable phenomena such as an increase in the minimum fixing temperature occur. Therefore, the amount of the trivalent or more polyvalent carboxylic acid or its derivative (d) used is 2.5 mol% or more and 15 mol% or more in all the constituent components
Less than is desirable. Specifically, as the (d) trivalent or higher polyvalent carboxylic acid or its derivative, 1,2,4-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid, 1,
2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-
Dicarboxyl-2-methyl-2-methylenecarboxypropane, tetra (methylenecarboxyl) methane, 1,
Examples thereof include 2,7,8-octanetetracarboxylic acid, empol trimer acid, their anhydrides, lower alkyl esters, and other trivalent or higher carboxylic acids.

The diol component of (e) is diethylene glycol, triethylene glycol, tetraethylene glycol, dipropylene glycol, tripropylene glycol, tetrapropylene glycol, di-tetramethylene glycol, tri-tetramethylene glycol, tetra-tetramethylene glycol. Can be mentioned. The diol component of (e) is used in an amount of 1.5 mol% or more and less than 10 mol% in all the constituent components.
If it is less than 10%, there is no effect to increase the fixing strength, and it is 10 mol%
The above is not preferable because it causes blocking of the toner.

The binder resin used in the present invention preferably has a softening point of 106 ° C. or higher and 160 ° C. or lower and a glass transition temperature of 50 ° C. or higher and 80 ° C. or lower. There is no effect in obtaining the offset region, and if the temperature exceeds 160 ° C., the unfavorable phenomenon occurs as the minimum fixing temperature increases. On the other hand, if the glass transition temperature is less than 50 ° C., the storage stability after toner formation will be poor, and if it exceeds 80 ° C., the fixability will be adversely affected, which is not preferable.

The polyester resin used in the present invention can be produced by polycondensing a polyvalent carboxylic acid component and a polyol component at a temperature of 180 to 250 ° C. in an inert gas atmosphere. At this time, in order to accelerate the reaction, a commonly used esterification catalyst such as zinc oxide, stannous oxide, dibutyltin oxide, dibutyltin dilaurate or the like can be used. For the same purpose, it can be produced under reduced pressure. The polyester resin of the present invention thus obtained is a resin having good grindability.

The polyester resin in the present invention is used as a main component of the binder resin, and has a number average molecular weight of 11,000 in order to further improve the pulverizability in toner formation.
The following styrene or styrene-acrylic resin, etc.
Other resins may be used up to 30% by weight in the binder resin.
When a toner is prepared, a property improving agent such as wax is added as an offset preventing agent, but when the polyester resin according to the present invention is used as a binder resin, the property improving agent may not be added, or when it is added. However, the addition amount is small.

The hydrophobic silica used in the present invention is obtained by treatment with an organosilicon compound having an organic group such as a trimethyl group, and specifically, it is obtained by hexamethyldisilazane or polydimethylsiloxane. And a degree of hydrophobicity of 80 or more by a methanol titration test. For example, those having a hydrophobicity of about 80 to 110 are used. Here, the degree of hydrophobicity refers to a numerical value obtained as follows.
That is, put 50 ml of pure water in a 200 ml beaker,
0.2 g of silica is added. And while stirring gently with a magnetic stirrer so that the water surface does not sink,
Methanol is added from a buret whose tip is immersed in water at the time of dropping, and the hydrophobicity is defined as the number of ml of dropped methanol when the floating silica begins to sink. In this case, methanol has a surface-active effect, and the floating silica is dispersed (i.e., begins to sink) in water through methanol when methanol is dropped, so the degree of hydrophobicity is large (the amount of methanol dropped is large). It means that the silica is so hydrophobic.

As the organosilicon compound used for such a hydrophobic treatment, the following compounds are generally mentioned. For example, hexamethyldisilazane, trimethylsilane, trimethylethoxysilane, triorganosilylmercaptan, trimethylsilylmercaptan, triorganosilylacrylate, vinyldimethylacetoxysilane, dimethylethoxysilane, dimethyldimethoxysilane, hexamethyldisiloxane, 1,3-divinyl. Tetramethyldisiloxane, 1,3-diphenyltetramethyldisiloxane, and polydimethyl having 2 to 12 siloxane units per molecule and one hydroxyl group bonded to Si in each terminal unit. There is siloxane. These are used alone or as a mixture of two or more.

The hydrophobic silica of the present invention has a pH of 5.5 to 8 when 4% by weight of the hydrophobic silica is dispersed in a water / methanol (1: 1) solution. This is because the hydrophobic silica of the present invention has a substantially hydrophobic surface. In addition, conventional hydrophobic silica that has been hydrophobized with a silicon halogen compound such as dimethyldichlorosilane, methyltrichlorosilane, and trimethylchlorosilane has hydrogen chloride generated during the reaction, which is completely Not removed 0.05
%, The pH was low, but in the case of the hydrophobic silica treated with hexamethyldisilazane or polydimethylsiloxane in the present invention, since hydrogen chloride is not generated, there is no such problem, and When treated with hexamethyldisilazane, ammonia is generated in the reaction, but since ammonia itself shows alkalinity,
It is considered that the pH becomes high.

The hydrophobic silica having such characteristics is
Those skilled in the art can easily manufacture the above-mentioned products by the method as described above. Examples of commercially available products include H-2000 (hydrophobicity 80, pH 7) manufactured by Wacker Chemical Co., TS-7 manufactured by Cabot.
20 (hydrophobicity 80, pH 5.8), TS-530 (hydrophobicity 110, pH 6.0)
Etc. can be used.

As the above-mentioned conventional hydrophobic silica, for example, R-972 manufactured by Nippon Aerosil Co., Ltd. is considered to be a dimethyl substitution product having the following structure on the surface side.

[Chemical 9]

On the other hand, H-2000 is considered to have the following structure. For H-2000, the reaction of hexamethyldisilazane used for hydrophobization was allowed to proceed sufficiently, and the residual amount of silanol groups on the silicon compound surface was almost 5
It is manufactured so as to be controlled to be not more than%.

[Chemical 10]

Further, TS-720 was obtained by treating with polydimethylsiloxane and is considered to have the following structure.

[Chemical 11]

It is considered that TS-530 has the following structure obtained by treating it with hexamethyldisilazane.

[Chemical formula 12]

The fine particles of such hydrophobic silica have an average particle size of 0.003 μm to 2 μm, preferably 0.0
It is preferably from 05 μm to 0.5 μm. The specific surface area by the BET method is preferably 20 to 500 m ² / g. If the average particle size exceeds 2 μm or the specific surface area is less than 20 m ² / g, the surface of the photoconductor tends to be damaged, and the average particle size is less than 0.003 μm or the specific surface area exceeds 500 m ² / g. The objects are very easily scattered and difficult to handle.

Further, the amount of hydrophobic silica added is required to be within a range in which the charge amount and fluidity are not particularly deteriorated at the time of high temperature and high humidity, and the generation of black spots is not recognized. 0.01 to 1.5 per part
Parts by weight, preferably 0.1 to 1.0 parts by weight. That is, the amount of hydrophobic silica added cannot be generally determined because the appropriate amount varies depending on the particle size of the toner, but generally 0.0 if the average particle size of the toner is about 10 to 15 μm.
There is no problem even if the amount is as small as 1 part by weight, usually 0.0
1 to 1.0 part by weight, preferably 0.1 to 0.5 part by weight is used. In this case, if the addition amount is less than 0.01 parts by weight, substantially no effective effect can be obtained, and if it exceeds 1.0 parts by weight, black spots may occur, which is not preferable. Further, in the case of a small particle size toner having an average particle size of 6 to 10 μm, the addition amount of the hydrophobic silica is usually 0.
1 to 1.5 parts by weight are used, preferably 0.2 to 1.
0 parts by weight. In this case, if the addition amount is less than 0.1 parts by weight, sufficient fluidity cannot be obtained, and if it exceeds 1.5 parts by weight, black spots may occur similarly to the above, which is not preferable. As the coloring material used in the developer composition of the present invention, conventionally known carbon black, iron black and the like can be used.

A charge control agent may be added to the electrostatic image developer composition of the present invention, if necessary. As the negatively chargeable toner, one kind or two or more kinds are used from all the negatively chargeable charge control agents known to be conventionally used for electrophotography. For example, metal-containing azo dyes such as "Varifast Black 3804", "Bontron S-31", "Bontron S-32", "Bontron S-34", "Bontron S-"
36 "(above, manufactured by Orient Chemical Co., Ltd.)," Aizen spirone black TVH "(manufactured by Hodogaya Chemical Co., Ltd.), copper phthalocyanine dye, metal complex of alkyl derivative of salicylic acid,
Examples thereof include "Bontron E-85" (manufactured by Orient Chemical Co.), quaternary ammonium salts such as COPY CHARGE NX VP 434 (manufactured by Hoechst), and the like.

It is also possible to use a main charge control agent and a charge control agent of opposite polarity together, and the amount of the charge control agent of the opposite chargeability is 1/2 or less of the amount of the charge control agent of the main chargeability. By so doing, it is possible to obtain a good visible image without lowering the density even if copying is performed continuously for 50,000 sheets or more.

As the positively chargeable toner, one kind or two or more kinds are used from all the positively chargeable charge control agents known to be conventionally used for electrophotography. As a specific example, a nigrosine-based dye, for example, "Nigrosine base
"EX", "Oil Black BS", "Oil Black SO",
Triphenylmethane derivatives containing a tertiary amine as a side chain, such as "Bontron N-01", "Bontron N-11" (all manufactured by Orient Chemical Co., Ltd.), such as COPY BLUE PR (manufactured by Hoechst), quaternary ammonium Salt compounds such as "Bontron P-51" (Orient Chemical Co., Ltd.), COPY CHARGE PX
VP 435 (manufactured by Hoechst), cetyl trimethyl ammonium bromide, and other polyamine resins such as "AFP-
B ”(manufactured by Orient Chemical Co., Ltd.) and the like. The above charge control agent is 0.1 with respect to the binder resin.
.About.8.0% by weight, preferably 0.2 to 5.0% by weight.

In order to control the electric resistance and charge amount of the toner or to enhance the cleaning property of the toner, in addition to the hydrophobic silica fine powder in the present invention, the average particle size is 0.
Fine powder of conductive metal oxide such as magnetite, tin oxide, zinc oxide, titanium oxide, etc. having a size of about 1 to 1 μm, fine particles of methyl methacrylate, polystyrene or methyl methyl methacrylate polymer, polytetrafluoroethylene, polyvinylidene fluoride Fine particles of fluororesin such as the above may be added together. These fine powders are contained in an amount of 0.01 to 5% by weight based on the weight of untreated toner, preferably 0.05.
~ 1.0 wt% is added.

Further, in order to use the toner of the present invention as a magnetic toner, magnetic powder may be contained. As such a magnetic powder, a substance that is magnetized when placed in a magnetic field is used, and examples thereof include powders of ferromagnetic metals such as iron, cobalt and nickel, and alloys and compounds such as magnetite, hematite and ferrite. The content of the magnetic powder is 15 to 70% by weight based on the weight of the toner. Further, the toner of the present invention is optionally mixed with carrier particles such as iron powder, glass beads, nickel powder and ferrite powder,
Used as a developer for an electric latent image.

The developer composition of the present invention can be applied to various developing methods. For example, there are a magnetic brush developing method, a cascade developing method, a method using a conductive magnetic toner, a method using a high resistance magnetic toner, a fur brush developing method, a powder cloud method and an impression developing method. The electrostatic image developer composition of the present invention thus obtained uses hydrophobic silica having a hydrophobicity of 80 or more. Therefore, a highly hydrophilic polyester resin is used as the main component of the binder resin. Nevertheless, even when the temperature and humidity are high, the chargeability and fluidity of the toner particles are not deteriorated, and the addition amount is extremely small, so that the generation of black spots can be prevented.

Particularly, the polyester resin in the present invention is
Since the pulverizability is good, the average particle size of the toner can easily be 6-10 μm.
High resolution and high image quality can be obtained by reducing the particle size to about m, but even in this case, the addition of the hydrophobic silica used in the present invention makes it possible to obtain fluidity and environment resistance that could not be achieved in the past. It is possible to secure the sex. The pH of the hydrophobic silica used in the present invention is 5.5 to 5.
Since it is 8, the inner wall of the tank for hydrophobic silica in the toner facility does not generate rust even after long-term continuous use. Further, even when such a toner using silica for surface treatment is mixed with a carrier made of iron powder or ferrite and stored as a developer for a long period of time, rust is unlikely to be generated on the carrier surface.

[0045]

The present invention will be described in more detail with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples. The composition ratios shown in the examples are all expressed in parts by weight.

Production Example 1 Polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane 164.9 g, ethylene glycol 86.5 g, 1,2-propylene glycol 84.4
g, dimethyl terephthalate 430.7 g, 1,2,4-benzenetricarboxylic acid anhydride (trimellitic anhydride) 10
6.6 g and 1.2 g of dibutyl tin oxide were placed in a glass 2-liter 4-necked flask, a thermometer, a stainless stir bar, a flow-down condenser, and a nitrogen inlet tube were attached, and nitrogen was placed in a mantle heater. 17 under airflow
The reaction was carried out at 0 ° C. for 5 hours and then at 220 ° C. with stirring. The degree of polymerization was traced from the softening point according to ASTM E 28-51 T, and the reaction was terminated when the softening point reached 130 ° C. The obtained resin is a pale yellow solid and has a DSC
The glass transition temperature by a (differential calorimeter) is 63 ° C.,
Let the said resin be binder resin (A).

Production Examples 2 to 3 Binder resins (B) and (C) were produced in the same manner as in Production Example 1 with the raw material compositions shown in Table 1.

[Table 1]

Preparation of Toner Materials having the following composition were thoroughly mixed with a Henschel mixer, kneaded with a twin-screw extruder, cooled, coarsely crushed, ground with a jet mill, and further classified with an air classifier. An untreated toner having the following average particle diameter was obtained. Untreated toner (1): Binder resin (A) 89 parts Carbon black "Regal 400 R" (manufactured by Cabot) 6 parts Negative charging control agent "CCA-7" (manufactured by ICI Japan) 2 parts Positively charged Charge control agent "Bontron N-11" (manufactured by Orient Chemical Co., Ltd.) 0.9 part Wax "Viscor 550-P" (manufactured by Sanyo Kasei Co., Ltd.) 2 parts Two types of untreated toner (2) having an average particle size of 10 and 7 μm: untreated The composition is the same as that of the untreated toner (1) except that the binder resin (A) in the treated toner (1) is changed to the binder resin (B). Average particle size 7 μm Untreated toner (3): Binder resin (C) 88 parts Carbon black “Carbon black # 44” (manufactured by Mitsubishi Kasei) 8 parts Negative charge control agent “Aizen spirone black T-77” (Hodogaya Chemical Co., Ltd.) 2 parts Wax "Viscor TS-200" (manufactured by Sanyo Kasei Co., Ltd.) 2 parts Two types of untreated toner (4) having an average particle size of 10 and 6 μm: Binder resin (A) 90 parts Carbon black " Carbon black # 44 "(manufactured by Mitsubishi Kasei) 6 parts Positive charge control agent" Bontron N-01 "(manufactured by Orient Chemical Co.) 2 parts Wax" Viscor TS-200 "(manufactured by Sanyo Kasei) 2 parts Average particle size Two types of untreated toner (5) having diameters of 10 and 7 μm: The same composition as the untreated toner (4) except that the binder resin (A) in the untreated toner (4) is changed to the binder resin (B). Average particle size 7 μm Untreated toner (6): Same composition as untreated toner (4) except that binder resin (A) in untreated toner (4) is changed to binder resin (C). 3 types with average particle size of 10, 7 and 6 μm

Example 1 The untreated toner (1) (product having an average particle size of 10 μm) 1,
To 000 g, 1.5 g of hydrophobic silica "HDK H-2000" (manufactured by Wacker Chemical Co., Ltd.) was added and mixed and adhered using a Henschel mixer to obtain Toner 1.

Example 2 The untreated toner (1) (product having an average particle size of 7 μm) 1, 0
2.5g of hydrophobic silica "HDK H-2000" against 00g
In addition, toner 2 is mixed and attached using a Henschel mixer.
Got

Example 3 The untreated toner (2) (product having an average particle size of 7 μm) 1, 0
3.5 g of hydrophobic silica "CAB-O-SIL TS-720" (manufactured by Cabot Corporation) was added to 00 g, and mixed and attached using a Henschel mixer to obtain Toner 3.

Example 4 The untreated toner (3) (product having an average particle size of 10 μm) 1,
For 000g, hydrophobic silica "CAB-O-SIL TS-530"
1.5 g (manufactured by Cabot) was added and mixed and attached using a Henschel mixer to obtain Toner 4.

Example 5 The untreated toner (3) (product having an average particle size of 6 μm) 1, 0
3.5 g of hydrophobic silica "CAB-O-SIL TS-530" was added to 00 g, and mixed and attached using a Henschel mixer to obtain Toner 5.

Example 6 The untreated toner (4) (product having an average particle size of 10 μm)
For 000g, 1.5% of hydrophobic silica "HDK H-2000"
g was added and mixed using a Henschel mixer to obtain toner 6.

Example 7 The untreated toner (4) (product having an average particle size of 7 μm) 1, 0
Hydrophobic silica "HDK H-2000" is 3.5g against 00g
In addition, toner 7 is mixed and adhered using a Henschel mixer.
Got

Example 8 The untreated toner (5) (product having an average particle size of 7 μm) 1, 0
To 00 g, 3.5 g of hydrophobic silica "CAB-O-SIL TS-720" was added and mixed and adhered using a Henschel mixer to obtain a toner 8.

Example 9 The untreated toner (6) (product having an average particle size of 10 μm)
To 000 g, 1.5 g of hydrophobic silica "CAB-O-SIL TS-530" was added and mixed and attached using a Henschel mixer to obtain Toner 9.

Example 10 The untreated toner (6) (product having an average particle size of 6 μm) 1, 0
To 100 g, 3.5 g of hydrophobic silica "CAB-O-SIL TS-530" was added and mixed and adhered using a Henschel mixer to obtain a toner 10.

Comparative Example 1 The untreated toner (1) (product having an average particle size of 7 μm) 1, 0
2.5 g of hydrophobic silica "AEROSIL R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added to 00 g, and mixed and adhered using a Henschel mixer to obtain Comparative Toner 1.

Comparative Example 2 The untreated toner (1) (product having an average particle size of 7 μm) 1, 0
4. Hydrophobic silica "AEROSIL R-972" is added to 00g.
Comparative toner 2 was obtained by adding 0 g and mixing and adhering it using a Henschel mixer.

Comparative Example 3 Untreated Toner (6) (Average Particle Size 7 μm) 1,0
2.5 g of hydrophobic silica "CAB-O-SIL TS-610" (manufactured by Cabot) was added to 00 g, and mixed and adhered using a Henschel mixer to obtain comparative toner 3.

Comparative Example 4 The untreated toner (6) (product having an average particle size of 7 μm) 1, 0
Comparative toner 4 was obtained by adding 5.0 g of hydrophobic silica "CAB-O-SIL TS-610" to 00 g and mixing and adhering it using a Henschel mixer.

Using the above toner, the average particle diameter of the toner,
The fluidity, the charge amount, and the generation of black spots were examined. The average particle diameter of the toner was measured by using a Coulter counter which is measured by an electric resistance method. That is, a Coulter counter-TA-II type (manufactured by Coulter) is used as a measuring device, an interface (manufactured by Nikkaki) for outputting number distribution and volume distribution, and a PC9801 personal computer (manufactured by NEC Corp.) are connected to form an electrolytic solution. Prepares a 1% aqueous sodium chloride solution using primary sodium chloride. As a measuring method, the electrolytic aqueous solution is 100 to 150 ml.
0.1 to 5 ml of a surfactant, preferably an alkylbenzene sulfonate, is added as a dispersant, and 2 to 20 mg of a measurement sample is further added. The electrolytic solution in which the sample is suspended is subjected to a dispersion treatment for about 1 to 3 minutes by an ultrasonic disperser, and 1 is used as an avator by the Coulter Counter-TA-II type.
The particle size distribution of 2 to 40 μ particles is measured using a 00 μ Avacher, and 50% of the weight distribution is taken as the average particle size.

The fluidity of the toner was measured by a toner drop amount tester described below. That is, it is a fluidity evaluation device provided with a screw and a buffer part that rotate at a speed of 10 revolutions per minute in a conical hopper. The measuring method is to put 300 g of the toner to be measured in a 1-liter plastic container, shake it by hand strongly up and down 10 times, and then
Transfer to a hopper, move the motor for 5 minutes, and determine the amount of toner dropped per minute from the weight of the toner that has fallen on the tray, and use this as the toner drop amount [g / min].

The charge amount was measured by a blow-off type charge amount measuring device described below. That is,
It is a specific charge measuring device equipped with a Faraday cage, a condenser, and an electrometer. The measuring method is as follows: a toner sample to be measured and a spherical ferrite carrier having a particle size of 250 to 400 mesh in a weight ratio of 10: 9.
A developer is prepared by thoroughly mixing and stirring at a ratio of 0. Then, the prepared developer was charged with W (g) (0.15 to 0.15) into a brass measuring cell equipped with a stainless steel mesh of 500 mesh (the size can be appropriately changed so that carrier particles do not pass).
0.20 g). Next, after suctioning from the suction port for 5 seconds, the atmospheric pressure regulator blows for 5 seconds at an atmospheric pressure showing 0.6 kg / m ² to remove only the toner from the cell. At this time, set the voltage of the electrometer 2 seconds after the start of the blow to V
(volt). Here, the capacitance of the capacitor is C (μ
F), the specific charge Q / m of this toner is calculated by the following equation. Q / m (μc / g) = (C × V) / m where m is the weight of the toner contained in the developer in W (g), the weight of the toner in the developer is T ( g), where D (g) is the weight of the developer, the toner concentration of the sample is expressed as T / D × 100 (%), and m is calculated by the following formula. m (g) = W × (T / D) / 100

As the developer for the toner having a negative charging property, 2
A mixture of spherical ferrite carriers having a particle size of 50 to 400 mesh in a ratio of 90 to 10 toner weight was used in a copying machine equipped with a selenium photoconductor, and was used as a developer for positively charged toner. Is 250 to 400
An amorphous iron powder carrier having a mesh particle size and a resin coated surface was mixed at a ratio of 90 to 10 toner weights, and the mixture was used in a copying machine equipped with an organic photoconductor to obtain 50,000 sheets each. Continuous copy under normal environment (23 ℃, 50
% RH) and high temperature and high humidity (35 ° C., 85% RH), and compared the change in charge amount and the occurrence of black spots during the printing durability test.

The results are shown in Tables 2 and 3, and Comparative Toners 1, 2, 3 and 4 are lower in charge amount after copying 50,000 sheets under high temperature and high humidity as compared with Toners 1 to 10. In all cases, black spots were generated under high temperature and high humidity, or background stain was severe and image evaluation was difficult.

[Table 2]

[Table 3]

[0068]

As is apparent from these results, when the hydrophobic silica of the present invention is added to the toner obtained by using the polyester resin of the present invention, the hydrophobic silica having a low degree of hydrophobicity, which has been conventionally used, is used. It is possible to secure higher fluidity and charge amount with a smaller addition amount than silica, and it is possible to keep the charge amount more stable even when used under high temperature and high humidity conditions. In particular, in the case of a toner having an average particle size of less than 10 μm, it has been necessary to increase the amount of hydrophobic silica added so far in order to ensure fluidity.
In the case of hydrophobic silica having a hydrophobicity of 80 or more such as 00, the addition amount can be reduced as compared with the conventional hydrophobic silica, so that it is possible to increase the margin for the occurrence of black spots. These effects were first achieved by the developer composition of the present invention.

Claims (5)

[Claims] (A) The following formula (1): (In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 7).
Is. ) The diol component represented by
When it is less than mol%, (b) the following formula (2): (In the formula, n is an integer of 2 to 6), and 10% by mole or more and less than 25% by mole of all the constituent components, (c) a divalent carboxylic acid or an acid anhydride thereof, or 2.5 mol% of the lower alkyl ester and (d) trivalent or higher polyvalent carboxylic acid or acid anhydride thereof or lower alkyl ester thereof in all constituents
Toner 1 is used in the electrostatic charge image developer composition using a polyester resin copolycondensed with 15% by mole or more and less than 15 mol% as a main component of the binder resin.
An electrostatic charge image developer composition comprising 0.01 to 1.5 parts by weight of hydrophobic silica having a hydrophobicity of 80 or more as measured by a methanol titration test, relative to 00 parts by weight. 2. The following formula (1): (In the formula, R is an ethylene or propylene group, x and y are each an integer of 1 or more, and the average value of x + y is 2 to 7).
Is. ) The diol component represented by
When it is less than mol%, (b) the following formula (2): (In the formula, n is an integer of 2 to 6), and 10% by mole or more and less than 25% by mole of all the constituent components, (c) a divalent carboxylic acid or an acid anhydride thereof, or 2.5 mol% of the lower alkyl ester and (d) trivalent or higher polyvalent carboxylic acid or acid anhydride thereof or lower alkyl ester thereof in all constituents
Toner 1 is used in the electrostatic charge image developer composition using a polyester resin copolycondensed with 15% by mole or more and less than 15 mol% as a main component of the binder resin.
When 4 parts by weight of hydrophobic silica was dispersed in a solution of water and methanol (1: 1) in an amount of 00 parts by weight, the pH was 5.5.
An electrostatic image developer composition comprising 0.01 to 1.5 parts by weight of hydrophobic silica of No. 8. 3. A polyester resin further comprising (e) the following formula (3): (In the formula, R ′ is an alkylene group having 2 to 4 carbon atoms, and n is 2 to
It is an integer of 4. 3. The electrostatic image developer composition according to claim 1, wherein the diol component represented by the formula (1) is contained in an amount of 1.5 mol% or more and less than 10 mol% in all the constituent components. 4. The electrostatic image developer composition according to claim 1, wherein the main component of the divalent carboxylic acid according to claim 1 or 2 is terephthalic acid or a lower alkyl ester thereof. 5. The softening point of the binder resin according to claim 1 or 2 is 106 ° C. or higher and 160 ° C. or lower, and the glass transition temperature is 50 ° C. or higher and 80 ° C. or lower. 2. The electrostatic image developer composition according to item 2.