JP2002196538A - Electrostatic charge image developing toner and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner which ensures incompatible properties such as low temperature fixability and anti-hot offsetting property in a well-balanced state. SOLUTION: A powdery resin (A) adjusted to 10-100 μm average particle diameter, a resin (B) having a lower melting temperature (T1/2 temperature by a contrast load extrusion type capillary rheometer) than the resin (A) and a colorant are mixed to prepare a mixture comprising the resins and the colorant. The mixture is melted and kneaded to prepare a molten kneaded material containing the colorant uniformly dispersed in the resins. The molten kneaded material is cooled and comminuted to produce the objective electrostatic charge image developing toner.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic image used in an electrophotographic method, an electrostatic recording method, or an electrostatic printing method.

[0002]

2. Description of the Related Art As an electrophotographic method, US Pat.
No. 97,691, JP-B-42-23910 and JP-B-43-24748, various methods are described. Usually, various methods are described on an electrostatic latent image carrier such as a photoconductive photoreceptor. An electrostatic latent image is formed by charging and exposure, and then the electrostatic latent image is developed with a toner composition containing a colorant in a binder resin, and the obtained toner image is transferred to a support such as transfer paper. In general, a visible image is formed by fixing.

In recent years, the amount of heat used for fixing toner has been steadily decreasing due to power saving, and the amount of heat given from the heat roll at the time of fixing has been reduced, and the pressing time by the heat roll has been shortened. High sharp melt properties and low-temperature fixability have become indispensable. In addition, it is required that the same toner be put into machines having different printing speeds and that the toner be fixed on various types of paper (thin paper, thick paper, postcards, etc.) having different thicknesses. And hot offset resistance.

Heretofore, polyester, polystyrene, styrene (meth) acrylate copolymer, styrene butadiene copolymer, epoxy resin and the like have been studied and used as resin materials for powder toners. Various proposals have been made according to use conditions.

[0005] In particular, for a resin for toner which is fixed by a heat roll, many design examples have been proposed for the purpose of improving the fixing performance and the anti-offset performance. In order to improve the viscoelastic behavior during heating and melting, Alternatively, the molecular weight distribution is expanded in order to suppress the change in melt viscosity due to temperature change,
Various techniques such as providing a crosslinked structure and applying a rubber elastic material have been studied.

In these conventionally proposed inventions, in order to improve the hot offset resistance, the softening point and molecular weight of the resin must be increased, and the cold offset resistance and the low-temperature fixability deteriorate. Conversely, when trying to improve the cold offset resistance and the low-temperature fixing property, the resin softening point or the glass transition point is lowered, and the hot offset resistance and the blocking resistance are deteriorated.

In order to achieve a good balance between conflicting properties such as low-temperature fixability and offset resistance, a technique using two kinds of resins having different softening points is known. This is to maintain the viscosity of the resin using a resin having a high softening point having a crosslinked structure or a branched structure, and to maintain the low-temperature fixability with the resin having a low softening point while maintaining the offset resistance at a high temperature. .

[0008]

However, when these two kinds of resins are kneaded, especially when the resin has a branched chain, the molecular chains of the resin are cut by shearing during kneading, and the branched structure is destroyed. Therefore, the softening point of the resin after kneading is lowered, and as a result, the desired high-temperature offset resistance cannot be obtained. In order to prevent this, means for reducing the shear during kneading, for example, a method of lowering the viscosity of the melt-kneaded material by increasing the kneading temperature, a method of reducing the stirring speed during kneading, a method of shortening the kneading time and the like are used. Although the softening point of the kneaded toner can be suppressed from lowering, the dispersion of the colorant becomes insufficient, resulting in a toner having a light color and no coloring power. Further, in the worst case, the toner may be fogged to stain the non-image area.

[0009] In order to impart high temperature offset resistance to the toner, a method of adding a release agent such as a wax is known. However, since the wax is easily released from the resin,
In order to uniformly disperse the wax in the resin, it is necessary to knead with sufficient shear. However, when kneading two kinds of resins as described above, kneading with a low share is necessary in consideration of the breaking of the molecular chains of the resin, but since the wax is not uniformly mixed with the resin, anti-offset at high temperatures is required. I can not get the nature.

Therefore, the present invention provides a wide range of fixing speed,
It is an object of the present invention to provide an excellent toner for developing an electrostatic image having a sufficient coloring power and having both an anti-offset property and a fixing property in a wide temperature range. Another object of the present invention is to provide a method for producing an excellent electrostatic image developing toner having a sufficient coloring power and having both an anti-offset property and a fixing performance in a wide fixing speed and a wide temperature range.

[0011]

Conventionally, in a normal toner production process, a resin material in the form of pellets or lump is pulverized by a mechanical crusher and passed through a mesh sieve having an opening of 1 to 5 mm. Since a resin powder having a large crushed particle diameter is used, it takes a long time to melt a resin having a high melting temperature and knead so that other components such as a coloring agent are uniformly dispersed in the resin. It takes time and a high share is required, and the above-mentioned problems have occurred. The present inventors have conducted intensive studies to solve this. As a result, when two or more resins having different melting temperatures are mixed and used, the resin having a high melting temperature is finely pulverized and mixed, and a colorant is used. It has been found that the above problem can be solved by kneading with the present invention and the like, and the present invention has been reached.

That is, according to the present invention, the average particle size is 10 μm or more.
A powdery resin (A) adjusted to 100 μm, a resin (B) having a lower melting temperature (T1 / 2 temperature by a constant load extrusion type capillary rheometer) than the resin (A), and a colorant are mixed. To prepare a mixture comprising a resin and a colorant, and then melt-knead the mixture to produce a melt-kneaded product in which the colorant is uniformly dispersed in the resin, and cool the melt-kneaded product. An object of the present invention is to provide a toner for developing an electrostatic image, which is manufactured by pulverization.

Further, according to the present invention, the average particle size is 10 μm to 1 μm.
Powdery resin (A) adjusted to 00 μm and resin (A)
A resin (B) having a lower melting temperature (T1 / 2 temperature by a constant load extrusion type capillary rheometer) and a colorant are mixed to form a mixture of the resin and the colorant, and then the mixture is formed. To produce a melt-kneaded product in which the colorant is uniformly dispersed in the resin, and the melt-kneaded product is cooled,
It is another object of the present invention to provide a method for producing a toner for developing an electrostatic image, wherein the toner is produced by pulverizing the powder.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, two different melting temperatures are used.
Seeds, or, if necessary, two or more resins,
The resin (A) having a high melting temperature is previously prepared with an average particle size of 10
It is adjusted to μm to 100 μm to obtain a powder or granules, and then mixed with the resin (B) having a low melting temperature and a colorant. A more preferable range of the average particle diameter to be adjusted in advance is from 20 μm to 80 μm. A more preferred range is from 20 μm to 70 μm. By adjusting the average particle diameter of the resin (A) having a high melting temperature to such a range, the resin (B) having a lower melting temperature than the resin (A) and a colorant can be mixed and melt-kneaded. Since A) is uniformly and finely dispersed in the mixture of the raw materials in advance, the whole can be uniformly kneaded with a smaller share and in a short time. As a result, the colorant can be finely dispersed without breaking the molecular chain of the resin (A), and by doing so, the melting temperature of the resin (A) at the time of designing does not decrease, and thus the production The melting temperature of the toner does not decrease. At this time, the average particle size of the resin (B) does not need to be particularly limited, but the average particle size of the resin material,
For example, the size may be the size of particles that have passed through a sieve of 1 to 5 mm.

In the present invention, the average particle size refers to SK LASER M
It is a value specified by X50 which is a measurement value of ICRON SIZER PRO-7000S (manufactured by Seishin Enterprise). This value is 10 μm
If the particle size is smaller than the above range, it is inconvenient to handle as a powder due to scattering in the air. If the particle size is larger than 100 μm, the effect of the present invention of dispersing the resin (A) in the raw material mixture in advance becomes thin, and a larger share is obtained. Otherwise, the whole raw material will not be uniformly dispersed.

In the present invention, the method of adjusting the resin (A) to have an average particle size of 10 μm to 100 μm in advance is not particularly limited, but may be pelletized using a usual mechanical or pneumatic pulverizer. The lump resin (A) can be pulverized to the above range to make a powder. Examples of such a device include a mechanical pulverizer such as a turbo mill and a kryptron, and an air pulverizer such as a spiral jet mill, a counter jet mill, and a collision plate jet mill.

In the present invention, the resin (A) is adjusted to the above-mentioned particle size range and mixed with other raw materials. However, the shape of the particles is not particularly limited as long as it is a powder. For example, when pulverized by the above-mentioned pulverizer, it becomes amorphous, but even in the case of a resin that has been made into spherical resin particles by emulsification after suspension polymerization, emulsion polymerization or resin production, the particle diameter is in the above range. If it is, it can be used without any problem.

In order to roughly grind the resin (B), it is general to roughly grind it with, for example, a rotoplex or a pulperizer.

As a means for measuring the properties of the resin such as thermal characteristics and viscosity, there is a constant load extrusion type capillary rheometer. The melting temperature in the present invention is defined as T1 / 2 measured by a constant load extrusion type capillary rheometer. The constant load extrusion type thin tube rheometer measures the viscous resistance of the melt as it passes through the thin tube, and specifically includes a flow tester “CFT-500” manufactured by Shimadzu Corporation.

FIG. 1 shows the structure of the cylinder section of the measuring apparatus. In the measurement by the temperature rise method using this device, the test is performed while raising the temperature at a constant rate over the course of the test time, so that the sample goes from the solid region to the transition region, through the rubbery elastic region to the flow region. The process can be measured continuously.
With this device, the shear rate at each temperature in the flow zone,
The viscosity can be easily measured.

FIG. 2 shows a flow curve obtained by the heating method. A
Region B (softening curve) shows the stage in which the sample is deformed under compression load and the internal voids are gradually reduced. Point B is the temperature at which the internal voids disappear and the transparent body or phase becomes uniform in appearance while having a non-uniform stress distribution, and indicates an inflection point from the solid region to the transition region. This temperature is defined as the softening temperature T
It is defined as s. The area of the BC (stop curve) shows the area where there is no apparent change in the position of the piston within a finite time and the sample begins to flow out of the die, including the rubbery elastic area of the sample. In the case of crystalline polymers, this region is short,
The softening temperature shows a value close to the outflow start temperature described in the next section. The point C indicates a temperature at which the sample starts flowing out of the die due to a decrease in the viscosity, and this temperature is defined as a flow start temperature Tfb. CD
An area E (outflow curve) indicates an area where the sample flows out of the die, and irreversible viscous flow is mainly performed. 1/2
The melting temperature T1 / 2 by the method is Tfb in the outflow curve.
Of the piston stroke between the flow and the outflow end temperature Tend
It shows the temperature at the point.

The softening temperature Ts, the outflow start temperature Tfb, the melting temperature T1 / 2 by the 1/2 method, and the outflow end temperature Tend specified here all affect the offset resistance and the low-temperature fixability at the time of fixing. If anything, the softening temperature T
s, the outflow start temperature Tfb greatly contributes to the low-temperature fixing property and the cold offset resistance, and the melting temperature T by the 1/2 method is large.
1/2, outflow end temperature Tend is hot offset resistance,
Large contribution to grindability.

Ts, Tfb, T1 / 2, and Tend measured by the constant load extrusion type capillary rheometer specified in the present invention are values obtained by measurement under the following conditions. <Measurement conditions of constant load extrusion type capillary rheometer> ・ Piston cross-sectional area 1cm ²・ Cylinder pressure 0.98MPa ・ Die length 1mm, Die hole diameter 1mm ・ Measurement start temperature 50 ° C ・ Temperature rising rate 6 ° C / min ・1.5g sample weight

In order to obtain the effect of the present invention, the resin (A) must have a T
It is desirable that the 1/2 temperature is 140 ° C to 230 ° C.
It is more preferably 145 ° C to 225 ° C, and still more preferably 145 ° C to 220 ° C.

Further, when the melting method of the resin (A) and the resin (B) by a constant load extrusion type capillary rheometer at 1/2 method is T1 / 2 (A) and T1 / 2 (B) respectively, It is desirable to fall within the range of 40 ° C. ≦ T1 / 2 (A) −T1 / 2 (B) ≦ 150 ° C. More preferably 45 ° C ≦ T
1/2 (A) −T1 / 2 (B) ≦ 150 ° C., more preferably 50 ° C. ≦ T1 / 2 (A) −T1 / 2 (B) ≦
150 ° C.

When the resin (A) satisfies the above performance,
THF-insoluble matter may be present in the structure. Since the resin containing a large amount of THF-insoluble components has a strong rubber elasticity and a high melt viscosity, the internal cohesive force of the melted toner layer is maintained even during heating and melting in the fixing process, the offset resistance is improved, and the fixing is improved. Even afterwards, it exhibits excellent friction resistance due to its toughness.

By blending the resin (A) and the resin (B) in a well-balanced manner, it is possible to provide a toner which sufficiently satisfies the anti-offset performance and the fixing performance in a wide temperature range. The resin (B) that melts at a lower temperature than the resin (A) is preferably a linear resin, but may have a slight branched or crosslinked structure. Further, two or more resins having different softening points may be used as the resin (B).

In the present invention, the weight ratio of the resin (A) to the resin (B) is from 1/9 to 9/1, particularly from 2/8 to 8 /
2 is preferred. When the ratio is 1/9 to 9/1, a toner for developing an electrostatic image having more contradictory properties such as low-temperature fixing property and high-temperature offset property can be obtained.

The resin that can be used in the present invention is not particularly limited, and a conventionally used resin for a toner can be used without any trouble. For example, polyester resin, polystyrene resin, styrene (meth) acrylate copolymer, styrene butadiene copolymer, epoxy resin, and the like can be used.
Among them, polyester resin, styrene (meth) acrylic resin and epoxy resin are preferable. Particularly, a polyester resin is preferable.

For example, when a polyester resin is used,
A dicarboxylic acid and a diol and, if necessary, a trivalent or higher valent monomer are added and dehydration-condensed by an ordinary method.

Examples of the dicarboxylic acid include phthalic anhydride, terephthalic acid, isophthalic acid, orthophthalic acid, naphthalenedicarboxylic acid, adipic acid, maleic acid, maleic anhydride, fumaric acid, itaconic acid, citraconic acid, hexahydrophthalic anhydride, Tetrahydrophthalic anhydride,
Examples thereof include dicarboxylic acids such as cyclohexanedicarboxylic acid, succinic acid, malonic acid, glutaric acid, azelaic acid, and sebacic acid, and derivatives and esterified products thereof.

The diols include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, dipropylene glycol,
Tripropylene glycol, butanediol, pentanediol, hexanediol, cyclohexanedimethanol, bisphenol A, polyoxyethylene- (2.
0) -2,2-bis (4-hydroxyphenyl) propane and its derivatives, polyoxypropylene- (2.0)
-2,2-bis (4-hydroxyphenyl) propane,
Polyoxypropylene- (2.2) -polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene- (6) -2,2
-Bis (4-hydroxyphenyl) propane, polyoxypropylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene-
(2.4) -2,2-bis (4-hydroxyphenyl)
Propane, polyoxypropylene- (3.3) -2,2
-Bis (4-hydroxyphenyl) propane and its derivatives, polyethylene glycol, polypropylene glycol, ethylene oxide-propylene oxide random copolymer diol, ethylene oxide-propylene oxide block copolymer diol, ethylene oxide-tetrahydrofuran copolymer Diol and polycaprolactone diol.

The polyvalent monomer having three or more valences includes
For example, trifunctional or higher polyvalent carboxylic acids such as trimellitic acid, trimellitic anhydride, pyromellitic acid, and pyromellitic anhydride, or derivatives or esterified products thereof, or sorbitol, 1,2,3,6-hexane Tetraol, 1,4-sorbitan, pentaerythritol,
1,2,4-butanetriol, 1,2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3 ,
5-trimethylolbenzene, and the like.

The resin (A) having a high melting temperature is preferably used in combination with a dicarboxylic acid, a diol, and a trivalent or higher polyvalent monomer. The resin (B) having a lower melting temperature than the resin (A) is desirably produced using a dicarboxylic acid and a diol. However, if necessary, a trivalent or higher polyvalent monomer may be appropriately added. It can also be manufactured.

The polyester resin that can be used in the present invention can be obtained by performing a dehydration condensation reaction or a transesterification reaction using the above-mentioned raw material components in the presence of a catalyst. The reaction temperature and reaction time at this time are not particularly limited, but are usually 2 to 150 ° C. to 300 ° C.
~ 24 hours.

As the catalyst for carrying out the above reaction, for example, zinc oxide, stannous oxide, tetrabutyl titanate, monobutyltin oxide, dibutyltin oxide, dibutyltin dilaurate, p-toluenesulfonic acid and the like can be appropriately used. .

The polyester resin used in the present invention may have a glass transition temperature (Tg) of 40 ° C. or higher, as long as it has an appropriate glass transition point as a toner. Is more preferable, and the temperature is particularly preferably from 50 to 80 ° C. The acid value is desirably 30 or less, more desirably 15 or less, and particularly desirably 10 or less. If the acid value is too high, the charge amount will decrease, and the desired charge amount cannot be obtained.

The styrene monomer used for the monofunctional styrene- (meth) acrylate copolymer resin which can be suitably used in the present invention includes, for example, styrene, α-methylstyrene, vinyltoluene, p-toluene, -
Examples include sulfone styrene and dimethylaminomethyl styrene.

As the monofunctional (meth) acrylate monomer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, isopropyl (meth) acrylate, n-butyl (meth) acrylate Alkyl (meth) such as, isobutyl (meth) acrylate, tertiary butyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate
Acrylates; alicyclic (meth) acrylates such as cyclohexyl (meth) acrylate; aromatic (meth) acrylates such as benzyl (meth) acrylate; hydroxyl-containing (meth) acrylates such as hydroxyethyl (meth) acrylate; (meth) acrylic Phosphoric acid group-containing (meth) acrylate such as roxyethyl phosphate; halogen atom-containing such as 2-chloroethyl (meth) acrylate, 2-hydroxy-3-chloropropyl (meth) acrylate and 2,3-dibromopropyl (meth) acrylate ( (Meth) acrylate; epoxy group-containing (meth) acrylate such as glycidyl (meth) acrylate; ether group-containing (meth) acrylate such as 2-methoxyethyl (meth) acrylate and 2-ethoxyethyl (meth) acrylate; Le (meth) acrylate,
A basic nitrogen atom or an amide group-containing (meth) acrylate such as diethylaminoethyl (meth) acrylate;

In addition, a monofunctional unsaturated compound copolymerizable therewith can be used if necessary. For example, carboxyl group-containing vinyl monomers such as (meth) acrylic acid, itaconic acid, crotonic acid, maleic acid, and fumaric acid; sulfo group-containing vinyl monomers such as sulfoethylacrylamide; nitrile group-containing vinyl monomers such as (meth) acrylonitrile; Vinyl methyl ketone,
Ketone group-containing vinyl monomers such as vinyl isopropenyl ketone; N-vinylimidazole, 1-vinylpyrrole,
A vinyl monomer containing a basic nitrogen atom or an amide group, such as 2-vinylquinoline, 4-vinylpyridine, N-vinyl-2-pyrrolidone, and N-vinylpiperidone, can be used.

Examples of the bifunctional or higher functional crosslinking agent include divinylbenzene, divinylnaphthalene, divinyl ether, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, and polyethylene. Glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,6-hexane glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, propylene glycol di (meth) acrylate, dipropylene Glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethanetetra (meth) acrylate, and the like. It is.

Alternatively, in the case of a resin using a styrene- (meth) acrylate copolymer obtained by copolymerizing the carboxyl group-containing vinyl monomer, a crosslinked resin can be formed by using a metal salt. A as metal salt
l, Ba, Ca, Cd, Co, Cr, Cu, Fe, Hg, Mg, Mn, Ni, P
b, Sn, Sr, halide such as Zn, hydroxide, oxide,
There are carbonates, carboxylate salts, alkoxylates, chelate compounds and the like. The crosslinking reaction can be carried out by heating and stirring in the presence of a solvent.

As a method for producing the styrene- (meth) acrylic acid ester copolymer, a usual polymerization method can be adopted, and the polymerization reaction is carried out in the presence of a polymerization catalyst such as solution polymerization, suspension polymerization, bulk polymerization and the like. Is performed.

As the polymerization catalyst, for example, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1′-azobis (cyclohexane-1-yl)
(Carbonitrile), benzoyl peroxide, dibutyl peroxide, butyl peroxybenzoate, and the like, and the amount used is 0.1 to 10.
0% by weight is preferred.

The resin (A) having a high melting temperature in styrene (meth) acrylic resin is desirably used in combination with the above monofunctional monomer and the above crosslinking agent.
Further, resin (B) having a lower melting temperature than resin (A)
Is desirably produced using the above-mentioned monofunctional monomer, but it can also be produced by appropriately adding a bifunctional or higher-functional polyvalent monomer as needed.

The styrene- (meth) acrylate copolymer resin used in the present invention only needs to have an appropriate glass transition point as a toner and has a glass transition temperature (Tg) of 40 ° C. or higher. Is preferable, and among them, T
g is more preferably 45 to 85 ° C, and 50 to 80 ° C.
Is particularly desirable. Further, the acid value is preferably 30 or less, more preferably 15 or less, and 1 or less.
It is particularly desirable that it is 0 or less. If the acid value is too high, the charge amount will decrease, and the desired charge amount cannot be obtained.

The binder resin used in the toner of the present invention can be used by partially or entirely adding a wax as a release agent to the resin. The amount used is preferably at least 30% by weight of the total resin, particularly preferably 1% by weight.
00% by weight.

The means for internally adding the wax to the resin is not particularly limited, but is not lower than the temperature at which the wax is melted, and under the usual conditions under which the monomer for producing the resin reacts, for example, from 120 ° C. to 250 ° C. Under the above heating conditions, a predetermined amount of wax is added to advance the polymerization reaction of the monomer, whereby a wax-containing resin can be obtained. Also, the timing of adding the predetermined amount of wax may be at the beginning of the polymerization reaction of the resin, may be in the middle of the polymerization reaction, or may be immediately before the polymerization reaction is completed and the resin is removed from the reaction vessel. . When the wax is added after the completion of the polymerization, it is necessary to take out the resin after sufficiently stirring the added wax so that the wax is uniformly dispersed in the resin.

As the coloring agent that can be used in the present invention, well-known coloring agents can be mentioned. Carbon blacks such as furnace black, channel black, acetylene black, thermal black, and lamp black classified according to the production method are used as black colorants, and phthalocyanine C.I. I. PigmentBl
ue 15-3, an indanthrone C.I. I. Pigm
ent Blue 60 and the like, and quinacridone C.I. I. Pigment Red 122,
Azo-based C.I. I. Pigment Red 22, C.I.
I. Pigment Red 48: 1, C.I. I. Pig
Ment Red 48: 3, C.I. I. Pigment
Red 57: 1, etc., and azo C.I. I. Pigment Yellow 12, C.I. I.
Pigment Yellow 13, C.I. I. Pigm
ent Yellow 14, C.I. I. Pigment
Yellow 17, C.I. I. Pigment Yellow
ow 97, C.I. I. Pigment Yellow 1
55, isoindolinone-based C.I. I. Pigment
Yellow 110, a benzimidazolone C.I.
I. Pigment Yellow 151, C.I. I. P
pigment yellow 154, C.I. I. Pigm
ent Yellow 180, and the like. The colorant content is in the range from 1 part by weight to 20 parts by weight. These colorants can be used alone or in combination of two or more.

The positively chargeable charge control agent used in the present invention is not particularly limited as long as it is a compound that imparts positively chargeable properties to the toner, but is preferably a triphenylmethane dye, a nigrosine dye, or a quaternary ammonium salt. And a resin containing a quaternary ammonium group and / or an amino group. These compounds can be used alone or in combination of two or more kinds of charge control agents. Examples of the positive charge control agent include the following products, but are not limited to the examples.

Examples of triphenylmethane dyes include “OIL BLUE” (Orient Chemical Co., Ltd.),
"Copy Blue PR" (Clariant Co., Ltd.)
And the like. Nigrosine dyes include “NIG
ROSINE BASE EX ”,“ OIL BRAC ”
KBS "," BONTORON N-01 "," BO
Notoron N-04 "," Bontoron N-
07 "," BONTORON N-21 "(all Orient Chemical Co., Ltd.) and the like. As a quaternary ammonium salt compound, "BONTORON P-51"
(Orient Chemical Co., Ltd.), "TP-302", "TP
-610 "," TP-415 "(above, Hodogaya Chemical Co., Ltd.)," COPY CHARGE PSY "(Clariant, Inc.) and the like. Examples of the resin containing a quaternary ammonium group and / or an amino group include “FCA
-201-PS "(Fujikura Kasei Co., Ltd.) and the like.

The negatively chargeable charge control agent used in the present invention is not particularly limited as long as it is a compound that imparts negative chargeability to the toner. Examples of the azo metal complex (salt) and salicylic acid metal complex ( Salts), benzyl acid metal complexes (salts), tetraphenyl metal complexes (salts), calixarene-type phenol condensates, cyclic polysaccharides, and resin-based charge control agents.

As the azo metal complex (salt), “BON
TORON S-34 "," BONTORON S-4 "
4 (orient Orient Chemical Co., Ltd.) “AIZEN SPIRONBL”
ACKTRH "(above, Hodogaya Chemical Co., Ltd.).
As salicylic acid-based metal complexes, "BONTORON"
E-81 "," BONTORON E-84 "," BO
NTORON E-88 "(orient Chemical Co., Ltd.) and the like. Examples of the benzyl acid metal complex include “LR-147” (Nippon Carlit Co., Ltd.). Examples of tetraphenyl-based metal complexes include “CO
PY CHARGENX "(Clariant Co., Ltd.) and the like. As the calixarene-type compound, “B
ONTORON E-89 "," BONTORON F
-21 "(above, Orient Chemical Co., Ltd.). As the cyclic polysaccharide, “COPY CH”
ARGE NCA "(Clariant Co., Ltd.). As the resin-based charge control agent, “FCA-1001-
NS "(Fujikura Kasei Co., Ltd.)," COPY LEVEL
NCS "(Clariant Co., Ltd.) and the like.

The content of the charge control agent is determined by the binder resin 10
It is preferably used in an amount of 0.1 to 10 parts by weight, more preferably 0.3 to 8 parts by weight, per 0 parts by weight. More preferably, it is 0.5 to 6 parts by weight.

The releasing agent used in the toner for developing an electrostatic image of the present invention includes known polypropylene wax, polyethylene wax, modified polyolefin wax, higher fatty acid ester, Fischer-Tropsch wax,
Graft polymerized waxes, higher aliphatic alcohols, amide waxes, natural waxes, etc. can be used. Among them, a release agent containing a higher fatty acid ester compound and / or an aliphatic alcohol compound as a main component is dispersible in a polyester resin. And good releasability and slidability are preferable. When a higher fatty acid ester wax and / or an aliphatic alcohol are added to the toner,
Better hot offset resistance and fixing strength can be obtained as compared with the same amount of polyolefin wax such as polypropylene wax and polyethylene wax.

The wax mainly containing a higher fatty acid ester compound is, for example, carnauba wax, montan wax, candelilla wax, rice wax, botaro wax or the like as a natural wax, and these waxes are purified and pulverized. Thus, the dispersion in the resin is further improved. Examples of the synthetic ester wax include higher fatty acid esters such as pentaerythritol.
As higher fatty acid esters, for example, "WEP-
5 "and" WEP-6 "(both Nippon Oil & Fats Co., Ltd.). Examples of the release agent mainly containing an aliphatic alcohol compound include those mainly containing a higher alcohol obtained by an oxidation reaction of paraffin, olefin or the like.

Examples of the release agent containing an aliphatic alcohol as a main component include “Unilin 425” and “Unilin 55”.
0 "(Petrolite Co., Ltd.)," NPS-921
0 "and" PARACOL 5070 "(Nippon Seiro Co., Ltd.) and the like.

Of the release agents containing a higher fatty acid ester compound or an aliphatic alcohol compound as a main component, those having a melting point in the range of 65 ° C. to 130 ° C. are particularly preferred because they greatly contribute to the offset resistance.

The release agent may be used alone or in combination, and good fixing offset performance can be obtained by adding 0.3 to 15 parts by weight, preferably 1 to 5 parts by weight to the binder resin. Can be When the amount is less than 0.3 parts by weight, the offset resistance is impaired, and when the amount is more than 15 parts by weight, the fluidity of the toner is deteriorated.

The toner for developing an electrostatic image according to the present invention comprises:
The binder resin, the colorant, the release agent, and the charge control agent composed of the above-mentioned resins are constituted as essential components, but other additives may be included. As an example, a lubricant such as metal soap and zinc stearate can be used, and as an abrasive, for example, cerium oxide and silicon carbide can be used.

The toner of the present invention contains the above-mentioned resin and colorant whose particle diameters have been adjusted as essential components, and further contains, if necessary, toner raw materials such as a release agent and a charge control agent before melt-kneading. And then uniformly mixed with a Henschel mixer or the like in advance. The conditions for this mixing are not particularly limited, but they may be mixed so as to obtain desired uniformity. For example, it is possible to change the mixing time, change the temperature at the time of mixing, change the rotation speed of the stirring, change the shape and combination of the stirring blades, and the like. In addition, various raw materials may be added in order and multi-stage mixing may be performed. The coloring agent and / or the charge control agent used here may be previously subjected to a flushing treatment so as to be uniformly dispersed in the resin, or a master batch melt-kneaded with the resin at a high concentration.

The above mixture is mixed by kneading means such as a two-roll, three-roll, pressure kneader or a twin-screw extruder. At this time, the colorant or the like may be uniformly dispersed in the resin, and the conditions for the melt-kneading are not particularly limited, but are usually from 80 to 200 ° C. for 30 seconds to 2 hours. The kneaded material is usually cooled by a cooling belt, a roller, or the like, but since the dispersion state of the release agent changes depending on the cooling conditions, the cooling conditions can be set so as to obtain a desired dispersion state.

If necessary, coarse pulverization is performed for the purpose of reducing the load in the fine pulverization step and improving the pulverization efficiency. The apparatus and conditions used for the coarse pulverization are not particularly limited, but the coarse pulverization is generally performed using a rotoplex, a pulperizer, or the like to a particle size of 3 mm mesh pass or less.

Then, fine pulverization is performed with a mechanical pulverizer such as a turbo mill or a kryptron, or an air pulverizer such as a spiral jet mill, a counter jet mill, or an impinging plate type jet mill, and then classified using an air classifier or the like. No. Fine grinding and classification equipment, conditions are the desired particle size,
What is necessary is just to select and set it so that it may become a particle size distribution and a particle shape. The volume average particle diameter of the particles constituting the toner is not particularly limited, but is usually adjusted to be 5 to 15 μm.

Usually, an external additive is mixed with the thus obtained toner using a mixer such as a Henschel mixer.

In the present invention, various additives (referred to as external additives) can be used for modifying the surface of the toner such as improving the fluidity of the toner and improving the charging characteristics. As the external additive that can be used in the present invention, for example, inorganic fine powders such as silicon dioxide, titanium oxide, and alumina and those obtained by surface-treating them with a hydrophobizing agent such as silicone oil, resin fine powders, and the like are used. .

Among these, hydrophobic silica obtained by surface-treating silicon dioxide with various polyorganosiloxanes, silane coupling agents and the like is preferably used as an external additive.

Specifically, there is one that is commercially available under the following trade names. AEROSIL; R972, R974, R202, R8
05, R812, RX200, RY200, R80
9, RX50, RA200HS, RA200H [Nippon Aerosil Co., Ltd.] WORKER; HDK H2000, H2050, H3
050, HVK2150 [Wacker Chemicals Co., Ltd.], Nipsil; SS-10, SS-15, SS-20,
SS-50, SS-60, SS-100, SS-50
B, SS-50F, SS-10F, SS-40, SS-
70, SS-72F, [Nippon Silica Industry Co., Ltd.], CABOSIL; TS-500, TS-530, TS-
610, TS-720, TG-308F, TG-709
F, TG-810G, TG-811F, TG820F
[Cabot Specialty Chemicals, Inc.].

The titanium oxide may be a hydrophilic grade or a hydrophobic grade surface-treated with octylsilane or the like. For example, there is one that is commercially available under the following trade names. Titanium oxide T
805 (Degussa Co., Ltd.), titanium oxide P25 (Nippon Aerosil Co., Ltd.) and the like. Examples of the alumina include aluminum oxide C (Degussa Corporation) and the like.

The particle size of these external additives is preferably not more than 1/3 of the diameter of the toner, particularly preferably 1/1.
0 or less. Further, these external additives may be used in combination of two or more kinds having different average particle diameters. The use ratio of silica is usually 0.05 to 5% by weight, and preferably 0.1 to 3% by weight, based on the toner.

When the electrostatic image developing toner of the present invention is used in a two-component developing system, the following carriers can be used. The core material of the carrier can be iron powder, magnetite, ferrite, etc. used in a normal two-component developing method, but among others, the true specific gravity is low, and the resistance is high.
Ferrite or magnetite which is excellent in environmental stability and easy to form into a sphere and has good fluidity is preferably used. The shape of the core agent can be used without any particular problem, such as spherical or amorphous. The average particle size is generally 10 to 500 μm, but is preferably 30 to 80 μm for printing a high-resolution image.

Examples of the coating resin for covering these core agents include polyethylene, polypropylene, polystyrene, polyacrylonitrile, polyvinyl acetate, polyvinyl alcohol, polyvinyl butyral, polyvinyl chloride, polyvinyl carbazole, polyvinyl ether polyvinyl ketone, and vinyl chloride. / Vinyl acetate copolymer, styrene / acrylic copolymer, straight silicone resin comprising organosiloxane bond or its modified product, fluororesin, (meth) acrylic resin, polyester, polyurethane, polycarbonate, phenolic resin, amino resin, melamine resin , Benzoguanamine resin, urea resin, amide resin, epoxy resin, acrylic polyol resin and the like can be used. Among these,
In particular, silicone resins, fluororesins, and (meth) acrylic resins are excellent in charge stability, coating strength, and the like, and can be more preferably used. That is, the resin-coated carrier used in the present invention is:
It is preferable that the magnetic carrier is a resin-coated magnetic carrier that uses ferrite or magnetite as a core agent and is coated with at least one resin selected from silicone resins, fluororesins, and (meth) acrylic resins.

In the non-magnetic one-component developing system, the non-magnetic toner conveyed by the toner carrier is frictionally charged by a layer thickness regulating member and its layer thickness is regulated, so that the non-magnetic toner is transferred onto the toner carrier. In general, a method of developing an electrostatic latent image by making the layer thinner and contacting or non-contacting the electrostatic latent image bearing member, and the toner of the present invention is particularly effective for this non-magnetic one-component developing toner. It is.

[0074]

Next, the present invention will be described in more detail with reference to Examples, but the present invention is not limited to the following Examples.

In the following, numerical values in the composition table indicate "parts by weight". In addition, measurement of the constant load extrusion type thin tube rheometer was performed using a piston cross-sectional area of 1 cm ² , a cylinder pressure of 0.98 MPa, a die length of 1 mm, a die hole diameter of 1 mm,
The measurement was performed under the conditions of a measurement start temperature of 50 ° C., a heating rate of 6 ° C./min, and a sample weight of 1.5 g.

[0076] Reference Example 1 (crosslinking Synthesis of Polyester A _L) terephthalic acid 332 parts by weight, 332 parts by weight of isophthalic acid, polyoxypropylene - (2.2) -2.2- bis (4-hydroxyphenyl) propane 460 Weight Part, polyoxyethylene-
(2.2) -2.2-Bis (4-hydroxyphenyl)
210 parts by weight of propane, 130 parts by weight of ethylene glycol and 30 parts by weight of glycerin were mixed with a stirrer, a condenser,
Put it in a 2 liter four-necked flask equipped with a thermometer,
Under a nitrogen gas stream, 4 parts by weight of tetrabutyl titanate was added, and while removing water generated by dehydration condensation, 2 parts by weight were added.
The reaction was carried out at 40 ° C. for 15 hours under normal pressure. Thereafter, the pressure was sequentially reduced, and the reaction was continued at 5 mmHg. The reaction is ASTM E
Tracking by softening point according to 28-517, softening point is 1
The reaction was completed when the temperature reached 43 ° C. The measured value of the obtained crosslinked polyester A _{L by} a constant load extrusion type capillary rheometer was Tfb: 115 ° C, T1 / 2: 145 ° C,
Tend: 153 ° C. Further, acid value: 3, Tg:
64 ° C. _AL was pulverized with a spiral jet mill to obtain A _L11 , A _L12 , and A _L13 shown in Table 1.

[0077] Reference Example 2 332 parts by weight of terephthalic acid (Synthesis of crosslinked polyester A _H), Epiclon N-695 7 parts by weight, Epiclon 8
50 10 parts by weight, diethylene glycol 21 parts by weight, neopentyl glycol 104 parts by weight, ethylene glycol 50 parts by weight, tetrabutyl titanate
5 parts by weight was used to perform a combination similar to the cross-linked polyester _{A L, Tfb: 175 ℃,} T1 / 2: 202 ℃, Te
nd: 213 ° C., an acid value: 3, Tg: 74 was obtained ° C. of crosslinked polyester A _H.

Epicron N-695 (manufactured by Dainippon Ink and Chemicals, Inc.) has a distribution in the number of epoxy groups in one molecule, and the number of epoxy groups in one molecule is two or more. Yes, a polyfunctional cresol novolak type epoxy resin having an average of 5 or more. Epoxy equivalent is 220 (g
/ eq). Epicron 850 (manufactured by Dainippon Ink and Chemicals, Inc.) is a bisphenol A type epoxy resin having an epoxy equivalent of 190 (g / eq). A _H11 in Table 1 was pulverized AH in spiral jet mill, A _H12, A
Got _H13

Reference Example 3 (Synthesis of Linear Polyester B _L ) Terephthalic acid 664
Parts by weight, 150 parts by weight of ethylene glycol, 632 parts by weight of polyoxyethylene- (2.2) -2,2-bis (4-hydroxyphenyl) propane, 4 liters each set with a stirrer, a condenser, and a thermometer The mixture was placed in a neck flask, and 4 parts by weight of tetrabutyl titanate was added thereto under a nitrogen gas stream, and the mixture was reacted at 240 ° C. for 15 hours under normal pressure while removing water generated by dehydration condensation. Thereafter, the pressure was sequentially reduced, and the reaction was continued at 5 mmHg. The reaction is AST
The reaction was followed by a softening point according to ME28-517, and the reaction was terminated when the softening point reached 80 ° C. The measured values of the obtained linear polyester B _{L by} a constant load extrusion type capillary rheometer were Tfb: 67 ° C., T1 / 2: 83
° C, Tend: 86 ° C, acid value was 8, Tg by DSC measurement was 50 ° C.

Reference Example 4 (Synthesis of linear polyester _BH ) Terephthalic acid 332
Parts by weight, 332 parts by weight of isophthalic acid, 650 parts by weight of polyoxyethylene- (2.0) -2,2-bis (4-hydroxyphenyl) propane, 150 parts of ethylene glycol
Using parts by weight, synthesis was performed in the same manner as the linear polyester A _L , Tfb: 103 ° C., T1 / 2: 118 ° C., Ten
d: 124 ° C, acid value: 5, and Tg: 58 ° C to obtain a linear polyester _BH .

Table 1 shows Tfb, T1 / 2, Tend, and Tg of the polyester resins obtained in Reference Examples 1 to 4.

[0082]

[Table 1]

Examples 1 to 5 <Production of a toner for developing an electrostatic image> 92 parts by weight of a polyester resin compounded in the proportions shown in Table 2, 5 parts by weight of Mogul L (carbon manufactured by Cabot Specialty Chemicals, Inc.) And 1 part by weight of Bontron S-34 (charge control agent manufactured by Orient Chemical Co., Ltd.), Viscol 550P
After mixing 2 parts by weight (Sanyo Chemical wax) with a Henschel mixer, the mixture was melt-kneaded with a biaxial extrusion kneader.
The kneaded product was cooled to room temperature, coarsely crushed by a hammer mill, finely crushed by a jet mill, and classified by an air classifier to obtain a 50% volume: 7.5 micron toner base material.

Next, 100 parts by weight of the toner base material, 1.0 part by weight of silica “NAX50 (average particle diameter of primary particles; 30 nm)” manufactured by Nippon Aerosil, and “R972 (average particle diameter of primary particles) of Nippon Aerosil ; 10 nm) "
After 0.5 part by weight was mixed with a Henschel mixer, the mixture was sieved to obtain a toner for developing an electrostatic image (a non-magnetic one-component developing toner). Tfb, T1 of each electrostatic image developing toner
/ 2, Tend and T difference (T1 / 2 (A) -T1 / 2
(B)) is shown in Table 2.

[0085]

[Table 2]

Comparative Examples 1 and 2 <Production of Toner for Developing Electrostatic Image> 92 parts by weight of a polyester resin compounded in the proportions shown in Table 3, 5 parts by weight of Mogul L (carbon manufactured by Cabot Specialty Chemicals, Inc.) And charge control agent Bontron S-3
4 (manufactured by Orient Chemical Co.) 1 part by weight, Viscol 550
2 parts by weight of P (Sanyo Kasei) was mixed with a Henschel mixer, and then melt-kneaded with a biaxial extruder. The kneaded product was cooled to room temperature, coarsely crushed by a hammer mill, finely crushed by a jet mill, and classified by an air classifier to obtain a 50% volume: 7.5 micron toner base material.

Next, 100 parts by weight of the toner base material, 1.0 part by weight of silica “NAX50 (average particle diameter of primary particles; 30 nm)” manufactured by Nippon Aerosil, and “R972 (average particle diameter of primary particles) of Nippon Aerosil ; 10 nm)
After 0.5 part by weight was mixed with a Henschel mixer, the mixture was sieved to obtain a toner for developing an electrostatic image (a non-magnetic one-component developing toner). Tfb, T1 of each electrostatic image developing toner
/ 2 and Tend are shown in Table 3.

[0088]

[Table 3]

Test Method 1 Low-Temperature Fixability and Offset Test An unfixed sample of A4 paper size was prepared using a test machine modified from a commercially available non-magnetic one-component developing system printer, and a heat roll fixing unit having the following specifications was used. The low-temperature fixability and the offset property were evaluated under the following test conditions. The fixed image sample for evaluating low-temperature fixability was 140 ° C.
And a fixed image sample for evaluating the offset property was prepared at 200 ° C. The fixed image for evaluation was a solid image of a square having a side of 2 cm. In order to evaluate low-temperature fixability, a mending tape (Sumitomo 3M, 81
0) was rubbed back and forth at a pressure of 5.0 KPa, and peeled off at an angle of 180 ° at a speed of 5 mm / sec to determine an image density remaining ratio. The image density was measured with a Macbeth image densitometer RD-918. Residual image density = image density after peel test / image density before peel test ◎ when the image density residual ratio is 90% or more, ○ when less than 90% and 80% or more, and when less than 80% and 70% or more △ (within practical range) and less than 70% as × were used as indices for evaluating low-temperature fixability. The offset start temperature was determined by observing the fixed image sample and visually confirming the presence or absence of the offset phenomenon. The evaluation criteria for the offset property were ◎: very good, ：: good, Δ: within the practical range, and ×: bad. The results are shown in Tables 2 and 3.

Test Method 2 Image Characteristics A black solid image was printed using a commercially available non-magnetic one-component developing system printer, and the image density was measured using a Macbeth densitometer.
The case where the measured value was less than 1.1 was evaluated as x, and the case of 1.1 or more was evaluated as ○.

The electrostatic image developing toners of Examples 1 to 5
Both low-temperature fixing property and offset property were excellent. On the other hand, the toners for developing electrostatic images of Comparative Examples 1 and 2 were poor in image quality.

[0092]

The toner for developing an electrostatic image of the present invention can be added with a high-viscosity resin by pulverizing the high-viscosity resin without disturbing the dispersion of the internal additives, and is excellent in low-temperature fixing property and high-temperature offset property. Toner. For this reason, the toner for developing an electrostatic image of the present invention is particularly excellent as a resin for toner that is fixed by a heat roll. Further, the electrostatic image developing toner of the present invention is particularly excellent as a non-magnetic one-component developing toner.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing a structure of a cylinder portion of a constant load extrusion type thin tube rheometer.

FIG. 2 is an example of a flow curve obtained by a heating method.

[Explanation of symbols]

 1 Piston 2 Cylinder 3 Heater 4 Die 5 Die holder 6 Sample

Claims (6)

[Claims] 1. A powdery resin (A) having an average particle diameter adjusted to 10 μm to 100 μm and a melting temperature lower than that of the resin (A) (T1 / T1 by a constant load extrusion type capillary rheometer).
2) is mixed with a colorant to prepare a mixture of the resin and the colorant, and then the mixture is melt-kneaded to melt-knead the colorant uniformly dispersed in the resin. A toner for developing an electrostatic image, wherein the toner is produced by producing a product, cooling the melt-kneaded product, and further pulverizing the product. 2. The toner for developing an electrostatic image according to claim 1, wherein the T1 / 2 temperature of the resin (A) measured by a constant load extrusion type capillary rheometer is from 140 ° C. to 230 ° C. 3. The temperature of each of the resins (A) and (B) measured by a constant load extrusion type capillary rheometer at a temperature of T
3. The method according to claim 1, wherein when 1/2 (A) and T1 / 2 (B), 40 ° C. ≦ T1 / 2 (A) −T1 / 2 (B) ≦ 150 ° C. 3. An electrostatic image developing toner. 4. The toner according to claim 1, further comprising a charge control agent. 5. The electrostatic image developing toner according to claim 1, further comprising a release agent. 6. A powdery resin (A) having an average particle size adjusted to 10 μm to 100 μm and a melting temperature lower than that of the resin (A) (T1 / T1 by a constant load extrusion type capillary rheometer).
2) is mixed with a colorant to prepare a mixture of the resin and the colorant, and then the mixture is melt-kneaded to melt-knead the colorant uniformly dispersed in the resin. A method for producing a toner for developing an electrostatic charge image, comprising producing a toner, cooling the melt-kneaded product, and further pulverizing the product.