JP2002139864A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electrostatic charge image developing toner having good environmental stability of the charged state, good hot storage resistance and fixing strength. SOLUTION: The electrostatic charge image developing toner contains toner particles containing at least a binder resin (A), a polymer (B) having a weight average molecular weight of 1,000-3,000 and a weight average molecular weight to number average molecular weight ratio of <=2.0 and a colorant and satisfies the relations of (1) a>1.0 and a>b and/or (2) a>b and c<aX.b1-X [where (a) is the grindability index of the binder resin (A); (b) is the grindability index of the polymer (B); (c) is the grindability index of a toner composition obtained by kneading and cooling toner materials; and X is the weight proportion of the binder resin (A) to the total amount of the binder resin(A) and the polymer (B)].

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 a printer or a copier employing an electrophotographic system, an electrostatic printing system or the like.

[0002]

2. Description of the Related Art In general, a toner for developing an electrostatic image is manufactured by a pulverizing method from the viewpoint of manufacturing easiness.
The pulverization method is a method in which at least a binder resin and a colorant are melted, kneaded, cooled, then coarsely pulverized and finely pulverized, and classified as required to obtain toner particles having a desired particle diameter. In recent years, the particle size of the toner has been reduced in order to achieve high image quality, and a polyester resin has been increasingly used as a binder resin in order to ensure low-temperature fixability. Against this background, the finely pulverizing step, which originally took a long time, took a longer time and caused a decrease in productivity.

In order to improve the pulverizability of the toner composition, one of means for improving the productivity is to add a so-called pulverization assistant (a resin brittler than the binder resin) to the toner composition before kneading. It has been known. For example, JP-A-4-257868 discloses a technique of including a C7-C10 aromatic petroleum resin in a binder resin such as a styrene-butadiene-based resin, and JP-A-8-278658 discloses a technique in which the hydrogenation rate of a binder resin is increased. Japanese Patent Application Laid-Open No. 11-65161 discloses a technique for containing a hydrogenated petroleum resin of 50% or more, and Japanese Patent Application Laid-Open No. H11-72956 discloses a technique for containing a copolymer containing a styrene-based monomer and an indene-based monomer in a binder resin. Japanese Patent Application Publication No. JP-A-2003-115125 discloses a technique in which a binder resin contains a copolymer containing an aliphatic hydrocarbon and an aromatic hydrocarbon having 9 or more carbon atoms.

[0004]

However, with these techniques, although the pulverizability can be improved, fogging occurs due to large fluctuations in the charge amount due to environmental fluctuations (deterioration of the toner charging environment stability). However, there is a problem that sufficient heat storage stability and fixing strength cannot be obtained.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner for developing an electrostatic image, which has good charging environment stability, heat resistance storage stability and fixing strength.

[0006]

According to the present invention, at least a binder resin (A), a polymer (B) having a weight average molecular weight of 1,000 to 3,000 and a weight average molecular weight / number average molecular weight of 2.0 or less,
And a toner for developing an electrostatic charge image comprising toner particles containing a colorant, wherein (1) a> 1.0 and a>b; and / or (2) a> b and c <a ^X · b ^{1- X} (where a is the crushing index of the binder resin (A), b is the crushing index of the polymer (B), c is the kneaded toner material,
The crushability index of the toner composition obtained by cooling,
Satisfies the relationship of the weight ratio of the binder resin (A) to the total amount of the binder resin (A) and the polymer (B)).

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The toner particles in the present invention comprise at least a binder resin (A), a specific polymer (B) and a colorant, (1) a> 1.0 and a>b; and (2) a> b and c <a ^X · b ^1-x (where a is the crushing index of the binder resin (A), b is the crushing index of the polymer (B), c is the kneaded toner material,
The crushability index of the toner composition obtained by cooling,
Is the weight ratio of the binder resin (A) to the total amount of the binder resin (A) and the polymer (B)), and preferably satisfies both the conditional expressions (1) and (2). Meets In the present invention, by using the specific polymer (B) and the binder resin (A) so as to satisfy either one of the conditional expressions (1) and (2), the polymer (B Can obtain toner particles effectively exposed to the surface of the toner particles, and can improve the charging environment stability, heat resistance storage stability and fixing strength. Further, by satisfying both conditional expressions (1) and (2), the stability of the charging environment is further improved. This is considered because more polymer (B) was effectively exposed on the surface of the toner particles.

[0008] Toner composition (kneaded material) containing binder resin (A) and polymer (B) having the above relationship
In the pulverization step, the polymer (B) is selectively pulverized. Specifically, the pulverization is performed while forming a pulverized surface so as to connect the dispersed particles of the polymer (B). It is believed that exposed toner particles are obtained.
More specifically, where the polymer (B) particles are present in the kneaded material, the pulverization is performed not at the contact surface (interface) between the binder resin (A) and the polymer (B) particles, but at the polymer (B) particles. Therefore, the pulverized surface is composed of the polymer (B), and it is considered that toner particles having the polymer (B) exposed on the surface are obtained.

In the above formula (1), when a is 1.0 or less, the selective pulverization of the polymer (B) becomes insufficient. Also,
If a is not more than b, the polymer (B) is not selectively pulverized during pulverization of the toner composition. In the above formula (2), when a is not more than b or c is not less than ^aX · b1 ^-X , the polymer (B) is not selectively pulverized during pulverization of the toner composition. In particular, if c is a a ^X · b ^1-X above, the ratio of the grindability index of toner compositions as shown in the graph of FIG. 1 (c) the binder resin (A) and the polymer (B) It approaches the corresponding value (the value on the broken line m), and the compatibility between the binder resin (A) and the polymer (B) becomes relatively high. Therefore, it is considered that the polymer (B) is hard to be selectively pulverized. .

Regarding the first equation “a> 1.0” of the above equation (1), preferably 3.0>a> 1.0, more preferably 2.0
>A> 1.2. Further, the second expression “a> of the above expression (1)
Regarding “b”, preferably, a> b + 0.5, and more preferably, a> b + 0.7. The first expression “a> of the above expression (2)
The preferred range and more preferred range of “b” are the same as those in the second formula of the above formula (1). Also, the above equation (2)
In the second formula “c <a ^X · b ^1-X ”, preferably, b
<C <a ^X · b ^1-X (in FIG. 1, indicated by a hatched area (not including the boundary of the area)), more preferably b + 0.45 ≦
c ≦ a ^X · b ^1−X −0.01 In the above formula (2), X
Is not particularly limited as long as X, a, b and c have the above-mentioned relationship, but is suitably 0.80 to 0.99, preferably 0.85 to 0.98.

The pulverizability index is one index indicating the easiness of crushing, and the smaller the value is, the easier the crushing is. In the present specification, a value measured according to the following is used as the grindability index. Sample (binder resin (A),
The polymer (B) or the toner composition (after kneading and cooling) that had been passed through a 2 mm mesh with a feather mill) was treated with a mechanical pulverizer (KTM-0: manufactured by Kawasaki Heavy Industries, Ltd.) at a throughput of F (5 kg / h). KTM
When pulverizing at a rotation speed of 12000 (rpm), a load power value W0 when no sample passes and a load power value W1 when a sample passes are recorded. Thereafter, the volume average particle diameter D (μm) of the pulverized product obtained by the KTM pulverization is measured with a Coulter Multisizer II (manufactured by Coulter Beckman). A grindability index is calculated from the obtained value based on the following equation. Grindability index = (D x (W1-W0)) / F

The polymer (B) used in the present invention has a weight average molecular weight (Mw) of 1,000 to 3,000, preferably 1,000 to 3,000.
2800, weight average molecular weight / number average molecular weight (Mw / Mn) is 2.0 or less, preferably 1.9 or less. Mw of polymer (B) is 1000
If it is less than 1, the glass transition point of the polymer (B) becomes low, so that the storage property (heat-resistant storage property) when the toner is left at a relatively high temperature is deteriorated, and practical use becomes difficult. On the other hand, when Mw exceeds 3000, the polymer (B) is difficult to be selectively pulverized because the material itself has poor pulverizability. In the present specification, Mw and Mn of a polymer or a resin are gel permeation chromatography (807-IT; manufactured by JASCO Corporation)
The values measured by are used.

Although the grindability index (B) of the polymer (B) is not particularly limited, it is usually desirably 0.8 or less, preferably 0.1 to 0.8, more preferably 0.2 to 0.6. Further, the glass transition point (Tg) of the polymer (B) is desirably 50 ° C or higher, preferably 55 to 85 ° C, more preferably 60 to 80 ° C. If the Tg is too low, the heat-resistant storage properties will deteriorate. The softening point of the polymer (B) is desirably 110 to 150 ° C, preferably 120 to 145 ° C.

In the present specification, the glass transition point of a polymer or a resin is determined by a differential scanning calorimeter (DSC-200: manufactured by Seiko Electronics Co., Ltd.).
Is used as a reference, alumina is used as a reference, a 10 mg sample is measured at a heating rate of 10 ° C./min between 20 ° C. and 120 ° C., and the shoulder value of the main endothermic peak is taken as the glass transition point. The softening point was measured using a flow tester (CFT-500: manufactured by Shimadzu Corporation) and the pores of the die (diameter 1 mm, length 1 mm),
Pressure 20 kg / cm ^2, the softening point temperature corresponding to 1/2 of the height of the flow ending point from the flow starting point for a sample of 1 cm ³ was melted runoff under the conditions of heating rate 6 ° C. / min And

The type of the polymer (B) is such that the polymer (B) is not compatible with the binder resin (A) even if it is melt-kneaded.
There is no particular limitation, for example, known aromatic monomers and
Homopolymers or copolymers of aliphatic monomers can be used.

The aromatic monomer is represented by the general formula (1):

Embedded image (Wherein R ¹ , R ² , R ³ and R ⁴ are each independently a hydrogen atom, a halogen atom, or an alkyl group having 1 to 4 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an n- A styrene group represented by a butyl group, preferably a hydrogen atom, a chlorine atom, a bromine atom or a methyl group) and a general formula (2);

Embedded image (Wherein, R ⁵ , R ⁶ and R ⁷ are each independently a hydrogen atom,
A halogen atom or an alkyl group having 1 to 6 carbon atoms, for example, a methyl group, an ethyl group, an n-propyl group, an n-butyl group, n
-Pentyl group, n-hexyl group, preferably a hydrogen atom, a chlorine atom, a bromine atom or a methyl group).

Specific examples of the styrene monomer include, for example, styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene, β-methylstyrene,
-Propenyltoluene, o-chlorostyrene, m-chlorostyrene, p-chlorostyrene, α-chlorostyrene, β-chlorostyrene, o-bromostyrene, m-bromostyrene, p-bromostyrene, α-bromostyrene, β -Bromostyrene and the like, preferably styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene, β-methylstyrene, 1-propenyltoluene, more preferably styrene, vinyltoluene,
α-Methylstyrene and isopropenyltoluene, more preferably styrene, α-methylstyrene and isopropenyltoluene. Specific examples of the indene-based monomer include, for example, indene, methylindene, ethylindene and the like, among which indene is particularly preferred. In this case, it is preferable to use a pure monomer having high purity from the viewpoint of suppressing the coloring, odor, and VOC amount of the resin. The aromatic monomers may be used alone or in combination.

Specific examples of the aliphatic monomer are not particularly limited as long as they can be polymerized with the above-mentioned aromatic monomer. For example, isoprene, piperylene, 1,3-butadiene, 1,3-pentadiene, 1,5-hexadiene , 2,3-dimethyl-1,3-butadiene, chloroprene, 2-bromo-1,3-butadiene and other diolefinic monomers; ethylene, propylene, butylene, isobutylene, 2-methyl-butene-1,2-methylbutene Monoolefin monomers such as -2; methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate,
Isobutyl acrylate, t-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, acrylic Alkyl acrylate monomers such as undecyl acrylate and dodecyl acrylate; methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, methacryl N-pentyl acid, isopentyl methacrylate, neopentyl methacrylate, 3- (methyl) butyl methacrylate, hexyl methacrylate,
Alkyl methacrylate monomers such as octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate and dodecyl methacrylate;
Unsaturated carboxylic acid monomers such as acrylic acid, methacrylic acid, itaconic acid and maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride,
Examples include vinyl acetate, vinyl benzoate, vinyl methyl ethyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether. Preferred are monoolefin-based monomers and diolefin-based monomers, more preferred are isoprene, piperylene, 2-methyl-butene-1, 2-methylbutene-2, and even more preferred is isoprene.
The aliphatic monomers may be used alone or in combination.

Among the polymers (B) comprising the above monomers, styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene and indene,
An aromatic monomer preferably composed of styrene, α-methylstyrene and isopropenyltoluene, and / or isoprene, piperylene, 2-methyl-butene-1
It is preferable to use a homopolymer or copolymer of an aliphatic monomer composed of and 2-methylbutene-2, preferably isoprene.

As such a preferred polymer (B),
Those synthesized from diolefins and / or monoolefins contained in cracked oil fractions by-produced from plants producing ethylene, propylene, etc. by steam cracking of petroleum can be preferably used.

In the present invention, more preferably, a polymer (B) containing at least styrene and / or α-methylstyrene as a constitutional unit is used. Specific examples of such a polymer (B) include, for example, polystyrene, poly-α
-Methylstyrene, styrene-α-methylstyrene copolymer, styrene-isopropenyltoluene copolymer, α-
Methylstyrene-isopropenyltoluene copolymer, α
-Methylstyrene-isopropenyltoluene-isoprene copolymer, styrene-isopropenyltoluene-isoprene copolymer and the like, preferably polystyrene, poly-α-methylstyrene, α-methylstyrene-isopropenyltoluene copolymer , Α-methylstyrene-
It is an isopropenyl toluene-isoprene copolymer.
The polymerization weight ratio in the polymer (B) is not particularly limited, but the ratio of styrene and / or α-methylstyrene to all monomers is 30 to 100% by weight, preferably 60 to 1% by weight.
It is desirably 00% by weight.

When polystyrene is used as the polymer (B), the weight average molecular weight is more preferably from 1,000 to 2,000. When poly-α-methylstyrene is used as the polymer (B), the weight average molecular weight is more preferably from 2,000 to 2,800. Α-methylstyrene-isopropenyltoluene copolymer or α as the polymer (B)
When using -methylstyrene-isopropenyltoluene-isoprene copolymer, its weight average molecular weight is 1800 to
More preferably, it is 2500.

The amount of the polymer (B) to be used is not particularly limited as long as X is within the above range, and is usually 1 to 25 parts by weight based on 100 parts by weight of a binder resin (A) described later. Department,
Preferably, 2 to 18 parts by weight is appropriate. Polymer (B) is 2
They may be used in combination of more than one kind, in which case the total amount thereof may be within the above range.

The type of the binder resin (A) is not particularly limited as long as it has the above-mentioned relationship between the incompatibility with the polymer (B) and the pulverizability index. Known binder resins, for example, polyester resin, (meth) acrylic resin, styrene-
(Meth) acrylic copolymer resin, epoxy resin, CO
C (cyclic olefin resin (for example, TOPAS-COC (manufactured by Ticona))) and the like. For a full-color toner that requires high-performance translucency, it is preferable to use a polyester resin. In the case where an oil coating type fixing device is used, the polyester resin is used. In a system which does not require oil application at the time of fixing or where a small amount of oil is applied, the polyester resin and the styrene- (meth) acrylic resin are used. Polymer resin, epoxy resin, COC (cyclic olefin resin (Ticona: T
OPAS-COC)) is preferably used.

In the present invention, as the polyester resin, a polyester resin obtained by polycondensing a polyhydric alcohol component and a polycarboxylic acid component can be used. As the dihydric alcohol component among the polyhydric alcohol components, for example, polyoxypropylene (2,2) -2,2-
Bis (4-hydroxyphenyl) propane, polyoxypropylene (3,3) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,2-bis (4-hydroxyphenyl) propane , Polyoxyethylene (2,0) -2,
Bisphenol A alkylene oxide adducts such as 2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neo Pentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,
Examples thereof include 6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polytetramethylene glycol, bisphenol A, and hydrogenated bisphenol A. Examples of the trivalent or higher alcohol component include sorbitol,
1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripetaerythritol, 1,2,4-butanetriol, 1,2,5-
Pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol,
Trimethylolethane, trimethylolpropane, 1,3,
5-trihydroxymethylbenzene and the like.

Examples of the divalent carboxylic acid component of the polycarboxylic acid component include, for example, maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, and cyclohexanedicarboxylic acid. Succinic acid, adipic acid, sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, isododecenylsuccinic acid, n-dodecylsuccinic acid, isododecylsuccinic acid, n-octenylsuccinic acid, isooctenylsuccinic acid, n- Examples include octylsuccinic acid, isooctylsuccinic acid, anhydrides and lower alkyl esters of these acids.

Examples of the trivalent or higher carboxylic acid component include 1,2,4-benzenetricarboxylic acid (trimellitic acid), 1,2,5-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-
Methylene carboxypropane, 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid, pyromellitic acid, empole trimer acid, anhydrides of these acids And lower alkyl esters.

In the present invention, a mixture of a raw material monomer for the polyester resin, a raw material monomer for the vinyl resin, and a monomer which reacts with the raw material monomers for both resins is used as the polyester resin in the same container. A resin obtained by performing a polycondensation reaction for obtaining a resin and a radical polymerization reaction for obtaining a vinyl resin in parallel can also be suitably used. The monomers that react with the raw material monomers of both resins are, in other words, monomers that can be used for both the condensation polymerization reaction and the radical polymerization reaction. That is, it is a monomer having a carboxy group capable of undergoing a polycondensation reaction and a vinyl group capable of undergoing a radical polymerization reaction, and examples thereof include fumaric acid, maleic acid, acrylic acid, and methacrylic acid.

The raw material monomers for the polyester resin include the above-mentioned polyhydric alcohol component and polycarboxylic acid component. Further, as a raw material monomer of the vinyl resin, for example, styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, p-
Styrene or styrene derivatives such as tert-butylstyrene and p-chlorostyrene; ethylenically unsaturated monoolefins such as ethylene, propylene, butylene and isobutylene; methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate and n-methacrylic acid -Butyl, isobutyl methacrylate, t-butyl methacrylate, n-pentyl methacrylate, isopentyl methacrylate, neopentyl methacrylate, 3-methacrylic acid
(Methyl) butyl, hexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate,
Alkyl methacrylates such as undecyl methacrylate and dodecyl methacrylate; methyl acrylate, n-propyl acrylate, isopropyl acrylate, n-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-pentyl acrylate , Isopentyl acrylate, neopentyl acrylate, 3-acrylate
Alkyl acrylates such as (methyl) butyl, hexyl acrylate, octyl acrylate, nonyl acrylate, decyl acrylate, undecyl acrylate, dodecyl acrylate; and the like, such as acrylic acid, methacrylic acid, itaconic acid and maleic acid. Saturated carboxylic acids; acrylonitrile, maleic ester, itaconic ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinyl methyl ethyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether and the like. Examples of the polymerization initiator for polymerizing the raw material monomer of the vinyl resin include, for example, 2,2′-azobis (2,4-dimethylvaleronitrile), 2,2′-azobisisobutyronitrile, 1,1 Azo- or diazo-based polymerization initiators such as' -azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4-dimethylvaleronitrile, benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl Examples include peroxide-based polymerization initiators such as peroxycarbonate and lauroyl peroxide.

The binder resin (A) has an acid value of 5 to 50 KOHmg /
g, preferably 10 to 40 KOH mg / g. In particular, when a polyester resin is used, by using a resin having such an acid value, the dispersibility of various colorants including carbon black and a charge control agent are improved, and a toner having a sufficient charge amount is obtained. be able to. In addition, the charging environment stability is further improved.

The acid value was determined by dissolving a 10 mg sample in 50 ml of toluene and titrating with a pre-specified N / 10 potassium hydroxide / alcohol solution using a mixed indicator of 0.1% bromthymol blue and phenol red. It is a value calculated from the consumption of N / 10 potassium hydroxide / alcohol solution.

In the present invention, particularly, in order to improve the fixability and the offset resistance as an oilless fixing toner, or to control the glossiness of an image in a full-color toner requiring transparency, a polyester is used. It is preferable to use two types of polyester resins having different softening points as the resin. The first polyester resin having a softening point of 95 to 120 ° C. is used to improve the fixing property, and the softening point is 130 to improve the offset resistance.
It is preferable to use a second polyester resin having a temperature of up to 160 ° C. In this case, the softening point of the first polyester resin is
If the temperature is lower than 95 ° C., the offset resistance decreases and the dot reproducibility decreases. If the temperature is higher than 120 ° C., the effect of improving the fixability becomes insufficient. When the softening point of the second polyester resin is lower than 130 ° C, the effect of improving the offset resistance becomes insufficient, and when the softening point is higher than 160 ° C, the fixability decreases. From such a viewpoint, the softening point of the first polyester resin is more preferably 100 to 115 ° C, and the softening point of the second polyester resin is 135 to 156 ° C. Further, from the viewpoint of further improving the heat resistance and the production efficiency of the toner, the glass transition points of the first and second polyester resins are 50 to 75 ° C., preferably,
It is desirable that the temperature be 55 to 70 ° C. When two kinds of resins are used as the binder resin as described above, the acid value of the mixed resin may be within the above range.

As the first polyester resin, a polyester resin obtained by polycondensing the above-mentioned polyhydric alcohol component and polyhydric carboxylic acid component, particularly, a bisphenol A alkylene oxide adduct as a polyhydric alcohol component is used as a main component. A polyester resin obtained by using at least one selected from the group consisting of only terephthalic acid, fumaric acid, dodecenylsuccinic acid, and benzenetricarboxylic acid as a polycarboxylic acid component as a main component is preferable. No.
(1) Mn of the polyester resin is 2000 to 6000, preferably 200
It is desirable that Mw / Mn is 0 to 3000 and Mw / Mn is 2 to 10, preferably 2 to 5.

As the second polyester resin, a polyester resin obtained by polycondensing a polyhydric alcohol component containing at least the above-mentioned trihydric or higher alcohol component or a trihydric or higher carboxylic acid component with a polycarboxylic acid is used. ,In particular
Bisphenol A alkylene oxide adduct as a main component as a dihydric alcohol component, using trimellitic acid as a trivalent or higher carboxylic acid component, terephthalic acid, fumaric acid, dodecenyl succinic acid as a divalent carboxylic acid component,
A polyester resin obtained by using at least one selected from the group consisting of benzenetricarboxylic acid as a main component is preferable. The polymerization molar ratio of the trivalent or higher alcohol component or the trivalent or higher carboxylic acid component is 2 to 20 m with respect to all the monomers.
ol%, preferably 5 to 15 mol%.

Further, as the second polyester resin,
Using a mixture of a raw material monomer of a polyester resin, a raw material monomer of a vinyl-based resin, and a bi-reactive monomer that reacts with the raw material monomers of both resins, a condensation polymerization reaction to obtain a polyester resin in the same container and a vinyl-based resin are performed. A polyester resin obtained by performing the obtained radical polymerization reaction in parallel may be used. Such a resin is preferable from the viewpoint of improving the dispersibility of the wax, the toughness, the fixing property, and the offset resistance of the toner. In this case, the content of the vinyl resin in the second polyester resin is 5 to 40% by weight, preferably 10 to 35% by weight.

The second polyester resin has Mn of 2,000 to 1,000.
0, preferably 2500-3500, Mw / Mn 10-50, preferably
Desirably, it is 20 to 40.

The weight ratio of the first polyester resin to the second polyester resin is 95: 5 to 30:70, preferably 90: 1.
It is preferably 0 to 40:60. By using the first polyester-based resin and the second polyester-based resin in such a range, the spread as a toner due to crushing at the time of fixing is small, the dot reproducibility is excellent, and the low-temperature and high-speed fixing properties are excellent. In the image forming apparatus described above, excellent fixability can be ensured. Also, excellent dot reproducibility can be maintained even when forming a double-sided image (when passing through the fixing device twice). If the proportion of the first polyester resin is smaller than the above range, the low-temperature fixability becomes insufficient and a wide fixability cannot be secured. When the proportion of the second polyester resin is less than the above range, the offset resistance is reduced, and the toner is crushed at the time of fixing, and the dot reproducibility tends to be reduced.

In the present invention, an epoxy resin may be used as a part or all of the binder resin (A). As the epoxy resin used in the present invention, a polycondensate of bisphenol A and epichlorohydrin can be suitably used. For example, epomic
R362, R364, R365, R367, R369 (all manufactured by Mitsui Petrochemical Industries, Ltd.), Epotote YD-011, YD-012, YD-014, YD
-904, YD-017 (all manufactured by Toto Kasei), Epicoat 100
Commercial products such as 2, 1004, 1007 (all manufactured by Shell Chemical Co., Ltd.) can also be used.

As the colorant used in the present invention, known pigments and dyes conventionally used as colorants for full-color toners can be used. For example, carbon black, aniline blue, calcoil blue, chrome yellow, ultramarine blue, Dupont oil red, quinoline yellow, methylene blue chloride, copper phthalocyanine, malachite green oxalate, lamp black, rose bengal, CI pigment red 48: 1 , CI Pigment Red 122, CI Pigment Red 57: 1, CI Pigment Red 184, CI Pigment Yellow 97, CI Pigment Yellow 12, C.I.
I. Pigment Yellow 17, CI Solvent Yellow
162, CI Pigment Yellow 180, CI Pigment
Yellow 185, CI Pigment Blue 15: 1, CI Pigment Blue 15: 3, and the like.

The content of the colorant in the magenta, cyan and yellow toners is preferably in the range of 2 to 15 parts by weight based on 100 parts by weight of the binder resin (A). The colorant used for the magenta, cyan, and yellow toners is preferably used as a master batch obtained by previously kneading and kneading the binder resin (A) to be used, and then pulverizing it. The amount used may be such that the content of the colorant in the obtained toner is within the above range.

In the black toner, a part or all of the coloring agent such as various types of carbon black, activated carbon and titanium black can be replaced with a magnetic substance. In the present invention, the content of the colorant in the nonmagnetic black toner is preferably in the range of 2 to 15 parts by weight based on 100 parts by weight of the binder resin (A). As the magnetic material, for example, known magnetic fine particles such as ferrite, magnetite, and iron can be used. The average particle size of the magnetic particles is preferably 1 μm or less, particularly preferably 0.5 μm or less, from the viewpoint of obtaining dispersibility at the time of production. When a magnetic substance is added from the viewpoint of preventing scattering while giving the properties as a non-magnetic toner, the amount of addition is 0.5 to 10 parts by weight per 100 parts by weight of the binder resin (A).
Parts by weight, preferably 0.5 to 8 parts by weight, more preferably 1 to 5 parts by weight
Parts by weight. If the addition amount exceeds 10 parts by weight, the magnetic binding force of the developer carrying member (with a built-in magnet roller) to the toner becomes strong, and the developing property is reduced. The amount of the magnetic substance in the magnetic toner is based on 100 parts by weight of the binder resin (A).
20 parts by weight to 60 parts by weight are preferred. If the addition amount is less than 20 parts by weight, toner scattering tends to increase, and if it exceeds 60 parts by weight, the toner charge amount cannot be stably ensured, and the image quality deteriorates.

In the present invention, other additives such as a releasing agent and a charge controlling agent may be contained in the toner particles. Wax is used as a release agent. As the wax, known waxes in the field of toner for developing electrostatic images can be used, for example, polyolefin waxes such as polyethylene wax and polypropylene wax,
Examples include natural waxes such as carnauba wax and rice wax, montan wax (montan ester wax), Fischer-Tropsch wax, paraffin wax, and the like. In particular, when a polyester resin is used as the binder resin, it is preferable to use an oxidized wax.

In the present invention, among the above-mentioned release agents, it is preferable to use a polypropylene wax from the viewpoint of improving the offset resistance, and the smear property (an image is already formed on one side at the time of automatic document feeding or duplex copying). It is preferable to use polyethylene wax from the viewpoint of preventing the image from being rubbed by a roller when the fed paper is fed and causing a deterioration in image quality such as bleeding or dirt on the image). Particularly preferred polypropylene wax from the above viewpoint has a melt viscosity at 160 ° C. of 50 to 300 cps and a softening point of 1
It is a polypropylene wax having a temperature of 30 to 160 ° C and an acid value of 1 to 20 KOHmg / g. In addition, a particularly preferred polyethylene wax from the above-mentioned viewpoint has a melt viscosity at 160 ° C. of 1
It is a polyethylene wax having a softening point of 000 to 8000 cps and a softening point of 130 to 150 ° C.

The melt viscosity of the wax is a value measured by a Brookfield viscometer. As the softening point of the wax, a value measured by a method similar to the method for measuring the softening point of the polymer or resin described above is used. As the acid value of the wax, a value measured by a method similar to the method for measuring the acid value of the resin described below is used.

The addition amount of the release agent is preferably 0.5 to 5 parts by weight based on 100 parts by weight of the binder resin (A). As a release agent
When two or more waxes are used, the total amount thereof may be within the above range.

As the charge control agent, known charge control agents which have been conventionally added for controlling the chargeability in the field of toner for developing electrostatic images can be used. For example, fluorine-containing surfactants, metal-containing dyes such as salicylic acid metal complexes and azo metal compounds, polymer acids such as copolymers containing maleic acid as a monomer component, quaternary ammonium salts, and azines such as nigrosine A system dye, carbon black and the like can be used.

In obtaining the toner of the present invention, first,
The above-mentioned binder resin (A), polymer (B), and colorant and other additives, for example, a release agent, a charge control agent, and the like are mixed by a known mixing device such as a Henschel mixer, and then kneaded. The mixture is melt-kneaded and cooled to obtain a kneaded product. As the kneading apparatus, a kneading apparatus having one or more rotary shafts (screw, rotor, roll, etc.) is used, but a screw extruder can be mainly used from the viewpoint of continuous productivity, long-term durability and the like. In the present invention, the grindability index measured using a kneaded product (toner composition) obtained as described above and passed through a 2 mm mesh with a feather mill is defined as “c”.

In the present invention, the polymer (B) is uniformly dispersed in the kneaded material, and further, the binder resin (A) and the polymer (B) having the above-mentioned relationship of the grindability index are used. Therefore, in the pulverizing step, the kneaded product is pulverized while forming a pulverized surface so as to connect the dispersed particles of the polymer (B), and the toner particles having the polymer (B) exposed on the surface can be obtained with high productivity. .

From the viewpoint of obtaining toner particles having the polymer (B) more exposed on the surface, the polymer (B) is uniformly dispersed in the kneaded product and has an average dispersed particle size of 0.05 to 2 μm, preferably It is preferably controlled to 0.1 to 1.5 μm, more preferably 0.3 to 1.2 μm. More preferably of the dispersed particles
95% or more are dispersed with a particle size of 2 μm or less. When the dispersion state of the polymer (B) in the kneaded material is controlled in such a manner,
The probability that the polymer (B) is exposed on the surface of the toner particles is further increased, and the productivity of the toner is improved.

The state of dispersion of the polymer (B) in the kneaded product obtained by cooling after melt-kneading is determined by the volume average particle size of the polymer (B) used, the mixing conditions before kneading, and the kneading conditions. Can be controlled by appropriately changing That is, when the particle size of the polymer (B) used is reduced, the dispersed particle size of the polymer (B) in the kneaded material is reduced. Further, when the mixing conditions and the kneading conditions are increased, the average dispersed particle size of the polymer (B) in the kneaded product becomes smaller. In particular,
For example, when a polymer (B) having a volume average particle size of 1 to 5 mm is mixed with another toner material by a Henschel mixer and melt-kneaded by a twin-screw extruder (PCM-30: Ikegai Iron Works), usually, Mixing speed of Henschel mixer is 20 ~ 50
m / s, the mixing time is 2 to 10 minutes, and the kneading temperature of the kneader is 12
0 to 200 ° C, the passage time of the object to be processed in the kneader is 1 to 5
By setting the time to minutes, a kneaded product in which the polymer (B) is uniformly dispersed with the above-mentioned dispersed particle size is obtained.

Since it is difficult to measure the dispersed particle size of the polymer (B) in the kneaded product, the polymer (B) in the particles of the coarsely pulverized toner product pulverized to a volume average particle size of about 2 mm in the pulverization step described below. ) May be within the above range. The dispersed particle size of the polymer (B) in the kneaded product and the dispersed particle size of the polymer (B) in the particles of the coarsely pulverized toner having a volume average particle size of about 2 mm do not change. Volume average particle size about 2mm
The particle size of the polymer (B) in the particles of the coarsely pulverized toner particles is determined by osmium staining after slicing the particles with a microtome, and TEM (transmission electron microscope).
It can be measured by taking a photograph of 0000 times.

Next, the kneaded material obtained as described above is pulverized, classified, and optionally subjected to a surface modification treatment. In the pulverization step, usually, the kneaded material is roughly pulverized by a feather mill or the like, and then a kryptron system (KTM: manufactured by Kawasaki Heavy Industries), an innomizer system (manufactured by Hosokawa Micron), a fine mill (manufactured by Nippon Pneumatic Industries) Crusher and / or a jet crusher (IDS; manufactured by Nippon Pneumatics Co., Ltd.) that applies a high-speed impact method in a stream of air such as a turbo mill (Turbo Kogyo Co., Ltd.) and / or crushes a collision plate or toner particles by putting them in a jet stream. ), I-type jet mill, PJM (both manufactured by Nippon Pneumatic Industries Co., Ltd.) and AFG (manufactured by Hosokawa Micron Corporation). Preferably, the kneaded material has a volume average particle size of about
After coarsely pulverizing with a feather mill to 2 mm, the volume is temporarily reduced to about 10 to 12 μm using a cryptotron system (KT).
(M: manufactured by Kawasaki Heavy Industries, Ltd.) and finely pulverized by a jet mill such as a jet pulverizer (IDS; manufactured by Nippon Pneumatic).

The classifier used in the classifying step includes:
Known classifiers can be used as long as the pulverized material can be classified to a desired particle size. For example, a TIPLEX type classifier (manufactured by Hosokawa Micron), an elbow jet (manufactured by Nippon Steel Mining), a DS classifier (Nippon Pneumatic) And the like can be used. In the present invention, the final volume average particle diameter of the toner particles is desirably 4 to 9 μm, preferably 6.5 to 8.5 μm.

It is preferable to add various organic / inorganic fine particles to the toner of the present invention as a fluidity adjusting agent after preparing the toner particles. Examples of the inorganic fine particles include various carbides such as silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, and diamond carbon lactam. , Various nitrides such as boron nitride, titanium nitride, zirconium nitride, various borides such as zirconium boride, various oxides such as titanium oxide, calcium oxide, magnesium oxide, zinc oxide, copper oxide, aluminum oxide, silica, colloidal silica Substances, various titanate compounds such as calcium titanate, magnesium titanate and strontium titanate, various sulfides such as molybdenum disulfide, various fluorides such as magnesium fluoride and carbon fluoride, aluminum stearate, stearic acid Calcium, zinc stearate, various metal soaps such as magnesium stearate, talc, various non-magnetic inorganic fine particles of bentonite can be used alone or in combination.

As the organic fine particles, styrene-based (meta-method) granulated by a wet polymerization method such as an emulsion polymerization method, a soap-free emulsion polymerization method, a non-aqueous dispersion polymerization method, or a gas phase method for the purpose of a cleaning aid or the like. ) Fine particles of acrylic, benzoguanamine, melamine, Teflon (registered trademark), silicon, polyethylene, polypropylene and the like can be used.

Inorganic fine particles, particularly silica, titanium oxide, alumina, zinc oxide and the like can be used in the form of a conventionally used hydrophobizing agent such as a silane coupling agent, a titanate coupling agent, silicone oil, silicone varnish, etc. Surface treatment is preferably performed by a known method using a treating agent such as a fluorinated silane coupling agent, a fluorinated silicone oil, a coupling agent having an amino group or a quaternary ammonium base, or a modified silicone oil. . The relatively large-diameter inorganic fine particles such as metal titanate and various organic fine particles may or may not be subjected to a hydrophobic treatment.

The fine particles are added in an amount of 0.1 to 6 parts by weight, preferably 0.5 to 3 parts by weight, based on 100 parts by weight of the toner particles. The fine particles may be used in combination of two or more kinds, and in that case, the total amount thereof may be within the above range.

[0058]

[Examples] (Production of binder resin (A)) Polyester resins A1 to A4 Table 1 shows a glass four-necked flask equipped with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube. The alcohol component and the acid component were added together with a polymerization initiator (dibutyltin oxide) in a molar ratio. This was reacted in a mantle heater by heating under stirring and heating under a nitrogen stream. And
The progress of the reaction was followed by measuring the acid number. When the acid value reached a predetermined value, the reaction was terminated and cooled to room temperature to obtain polyester resins H1, L1 and L2. Each of the obtained polyester resins is coarsely crushed to 1 mm or less.
Used in combination as ~ A4. In the table, PO represents polyoxypropylene (2,2) -2,2-bis (4-hydroxyphenyl) propane, and EO represents polyoxyethylene (2,0) -2,2.
-Bis (4-hydroxyphenyl) propane, TPA represents terephthalic acid, TMA represents trimellitic acid, and FA represents fumaric acid.

[0059]

[Table 1]

(Production of polymer (B)) Resin B1 150 g of styrene (purity 99.9%) and 150 g of toluene were charged into an autoclave, and the temperature of B was kept at 5 ° C. with stirring.
1.5 g of F ₃ -phenol complex was added dropwise in about 10 minutes. Thereafter, stirring was continued for another 3 hours. Next, 50 ml of a 5% aqueous sodium hydroxide solution was added, and the mixture was vigorously stirred for 30 minutes to decompose the catalyst. The aqueous layer was separated, and the polymerized oil was washed with water until neutral. Evaporation removed polystyrene as a residue. The polymer was designated as resin B1, and physical properties are shown in Table 2.

Resin B2 150 g of α-methylstyrene (purity 99.8%) and toluene
150 g was charged into an autoclave, and 1.5 g of a BF ₃ -phenol complex was added dropwise over about 10 minutes while maintaining the temperature at 5 ° C. with stirring. Thereafter, stirring was continued for another 3 hours. Next, 50 ml of a 5% aqueous sodium hydroxide solution was added, and the mixture was vigorously stirred for 30 minutes to decompose the catalyst. The aqueous layer was separated, and the polymerized oil was washed with water until neutral. Evaporation gave poly-α-methylstyrene as a residue. The polymer was designated as resin B2, and the physical properties are shown in Table 2.

Resin B3 250 g of α-methylstyrene (purity 99.8%), 250 g of isopropenyltoluene and 500 g of toluene are placed in a three-necked flask, and a boron trifluoride phenol complex is added little by little with stirring, and dry ice / acetone is added. 20 while cooling in the bath
The reaction was performed at a temperature of 3 ° C. for 3 hours. Subsequently, the catalyst was removed by deactivating the catalyst by adding an alkali, and concentrated to drive off the solvent and unreacted monomer, thereby obtaining an α-methylstyrene-isopropenyltoluene copolymer as a residue. The polymer was designated as resin B3, and the physical properties are shown in Table 2.

Resin B4 200 g of isopropenyltoluene (purity 98%), 200 g of α-methylstyrene (purity 98%), 120 g of a C5 petroleum fraction (isoprene) obtained by pyrolysis of petroleum naphtha, and 500 g of toluene The mixture was placed in a single-necked flask, and the boron trifluoride phenol complex was added little by little with stirring, and reacted for 3 hours while cooling in a dry ice / acetone bath. Next, an aqueous NaOH solution was added and the mixture was vigorously stirred to decompose the catalyst, and then the aqueous phase was separated to obtain an oily polymer. Further, the oily polymer was washed with water until it became neutral, and then the unreacted oil and the solvent were distilled off with heating under reduced pressure to obtain a white mass of α-methylstyrene-isopropenyltoluene-isoprene copolymer as a residue. The polymer was designated as resin B4, and the physical properties are shown in Table 2.

Resin B5 Polystyrene was obtained by the same method as that for Resin B1, except that the reaction time was changed to 2 hours. The polymer was designated as resin B5, and the physical properties are shown in Table 2. -Resin B6 Poly-α-methylstyrene was obtained in the same manner as in Resin B2 except that the reaction time was changed to 4 hours. Resin B6
Table 2 shows the physical properties.

Resin B7 Except that the reaction time was changed to 4 hours, α
-Methylstyrene-isopropenyltoluene copolymer was obtained. The polymer was designated as resin B7 and the physical properties are shown in Table 2. -Resin B8 Poly-α-methylstyrene was obtained in the same manner as in Resin B2 except that the reaction time was changed to 5 hours. Resin B8
Table 2 shows the physical properties.

[0066]

[Table 2]

(Manufacture of Pigment Masterbatch) The pigment used for the manufacture of a full-color toner was used as a pigment masterbatch obtained by the following method. The binder resin and the pigment used in each Example or Comparative Example were charged into a pressure kneader at a weight ratio (resin: pigment) of 7: 3, and the mixture was heated at 120 ° C.
Kneaded for 1 hour. After cooling, the mixture was roughly pulverized with a hammer mill to obtain a pigment master batch having a pigment content of 30% by weight. CI Pigment Red 184 (manufactured by Dainippon Ink) was used as the pigment.

(Production of Toner) Example 1 A polyester resin A1 and a pigment masterbatch were used in a proportion of 90 parts by weight of the polyester resin A1 and 3 parts by weight of CI Pigment Red 184, and 10 parts by weight of the resin B1 and 10 parts by weight of the resin B1. Add 2 parts by weight of a molding agent (low molecular weight polypropylene; 100TS; manufactured by Sanyo Chemical Co., Ltd.) and use a Henschel mixer with a peripheral speed of 40 m / s.
While controlling so that the material temperature does not exceed 45 ° C.
After mixing for 5 minutes, the mixture was melt-kneaded using a twin-screw extruder (PCM-30: manufactured by Ikegai Iron Works Co., Ltd.) with the discharge section removed. The kneading temperature was 170 ° C., and the passage time of the object was about 1 minute. The obtained kneaded material was rolled to a thickness of 2 mm with a cooling press roller, cooled with a cooling belt, and coarsely pulverized with a feather mill. After that, pulverize with a mechanical pulverizer (KTM: manufactured by Kawasaki Heavy Industries Co., Ltd.) to an average particle size of about 10 to 12 μm, and further classify the pulverized coarse powder with a jet pulverizer (IDS: manufactured by Nippon Pneumatic Industries Co., Ltd.). Classification was performed using a rotor classifier (Tiplex classifier type: 100ATP: manufactured by Hosokawa Micron) to obtain toner particles having a volume average particle diameter of 8.2 μm. To the toner particles, 0.4% by weight of hydrophobic silica (H2000; manufactured by Hoechst Japan Co., Ltd.) and 0.6% by weight of hydrophobic titania (STT30A: manufactured by Titanium Industry Co., Ltd.) were added and mixed with a Henschel mixer to obtain a magenta toner. I got

Example 2 A polyester resin A1 and a pigment master batch were used except that 95 parts by weight of polyester resin A1 and 3 parts by weight of CI Pigment Red 184 were used, and 5 parts by weight of resin B1 were used. A magenta toner was obtained in the same manner as in Example 1. Example 3 Example 1 was repeated except that the polyester resin A1 and the pigment masterbatch were used so that the polyester resin A1 was 85 parts by weight and the CI Pigment Red 184 was 3 parts by weight, and the resin B1 was 15 parts by weight. Similarly, a magenta toner was obtained.

Example 4 A magenta toner was obtained in the same manner as in Example 1 except that the resin B1 was changed to the resin B2. Example 5 A magenta toner was obtained in the same manner as in Example 1 except that the resin B1 was changed to the resin B3. Example 6 A magenta toner was obtained in the same manner as in Example 1 except that the resin B1 was changed to the resin B4.

Example 7 A magenta toner was obtained in the same manner as in Example 1, except that the polyester resin A1 was changed to the polyester resin A2, and the volume average particle size was changed to 7.0 μm. Example 8 The pigment masterbatch was changed to acidic carbon black (Mogal L; manufactured by Cabot Corp .; pH 2.5; average primary particle size 24 nm). The polyester resin A1 and the acidic carbon black were combined with the polyester resin A1; 90 parts by weight. And acid carbon black; the same as in Example 1, except that it was used in an amount of 8 parts by weight, and 2.0 parts by weight of a zinc complex of salicylic acid (E-84: manufactured by Orient Chemical Industries) was further added as a charge control agent. Similarly, a black toner was obtained. Example 9 The same procedures as in Example 1 were carried out except that the polyester resin A1 and the pigment masterbatch were used so as to be 99 parts by weight of the polyester resin A1 and 3 parts by weight of CI Pigment Red184, and 1 part by weight of the resin B1. Similarly, a magenta toner was obtained.

Comparative Example 1 A magenta toner was obtained in the same manner as in Example 1 except that the resin B1 was changed to the resin B5. Comparative Example 2 A magenta toner was obtained in the same manner as in Example 1 except that the resin B1 was changed to the resin B6. Comparative Example 3 A magenta toner was obtained in the same manner as in Example 1 except that the resin B1 was changed to the resin B7.

Comparative Example 4 A magenta toner was obtained in the same manner as in Example 1 except that the resin B1 was changed to the resin B8. Comparative Example 5 A magenta toner was obtained in the same manner as in Example 1, except that the polyester resin A1 was changed to the polyester resin A3 and the resin B1 was changed to the resin B2. Comparative Example 6 A magenta toner was obtained in the same manner as in Example 1, except that the polyester resin A1 was changed to the polyester resin A4 and the resin B1 was changed to the resin B2.

The physical properties of the obtained toner and the values of the prescribed relational expressions are shown in the table together with the production conditions.

[Table 3]

<Heat Resistance Storage Property> After leaving 10 g of the toner at a high temperature of 50 ° C. for 24 hours, the toner was visually checked to evaluate the heat resistance storage property. ：: no aggregates were observed; Δ: less than 10 aggregates; ×: 10 or more aggregates.

In the following evaluation, a developer obtained by mixing the toner obtained in Examples and the like and a carrier described later so that the toner mixing ratio becomes 6% by weight was used.

<Stability of Charging Environment (Charging Amount (HH / LL) and Environmental Fluctuation Range)> Each developer was used in a low temperature and low humidity environment (10 ° C., 15%).
(Hereinafter referred to as LL) for one day, and the charge amount for 30 minutes was measured by an electrolytic separation method. Use each developer in a high temperature and high humidity environment (30
(H, HH) for one day, and the charge amount for 30 minutes was measured by an electrolytic separation method. LL (low temperature and low humidity environment)
The charge environment stability was evaluated based on the difference between the charge amount of HH and the charge amount of HH (high temperature and high humidity environment). ；: The absolute value of the difference was 7 or less; Δ: The absolute value of the difference was 7 or more and less than 7.5; ×: The absolute value of the difference was 7.5 or more.

<Fixing Strength> A 1.5 cm × 1.5 cm solid image (adhesion) was obtained with a digital copying machine (DiALTA Di350; manufactured by Minolta) while changing the fixing temperature in the range of 120 ° C. to 170 ° C. in steps of 2 ° C. An amount of 2.0 mg / cm ² ) was printed, each image was folded in two from the center, and the peelability of the image was visually evaluated. The temperature between the fixing temperature when the image was slightly peeled off and the lower limit fixing temperature at which the image was not peeled off at all was defined as the fixing lower limit temperature. ；: Fixing lower limit temperature was less than 146 ° C .; Δ: Fixing lower limit temperature was 146 ° C. or more and less than 152 ° C. (no problem in practical use); ×: Fixing lower limit temperature was 152 ° C. or more (practical) Problematic).

[0079]

[Table 4]

(Manufacture of Carrier) As the carrier, a resin-coated carrier manufactured as described below was used. First, 100 parts by weight of methyl ethyl ketone was added to a 500-ml volumetric flask equipped with a stirrer, a condenser, a thermometer, a nitrogen inlet tube, and a dropping device. Separately, 100 parts by weight of methyl ethyl ketone, 36.7 parts by weight of methyl methacrylate, 5.1 parts by weight of 2-hydroxyethyl methacrylate, 58.2 parts by weight of 3-methacryloxypropyl tris (trimethylsiloxy) silane and 1,
1'-azobis (cyclohexane-1-carbonitrile)
A solution was prepared by dissolving parts by weight, and this solution was added dropwise to the above flask at 80 ° C. over 2 hours under a nitrogen atmosphere.
After aging for a time, a resin was obtained. Next, with respect to the obtained resin, isophorone diisocyanate / trimethylolpropane adduct (IPDI / TMP system: NCO% = 6.1) was used as a crosslinking agent.
%) Was added so that the OH / NCO molar ratio became 1/1, and then diluted with methyl ethyl ketone to obtain a coat resin solution having a solid ratio of 3% by weight. Then, the core resin composed of fired ferrite powder having an average particle diameter of 50 μm (F-300, manufactured by Powder Tech Co., Ltd.) was coated with the above coating resin solution in an amount of 1.
It is applied by a spira coater (manufactured by Okada Seiko Co., Ltd.) to a concentration of 5% by weight, dried, and the obtained carrier is left to stand in a hot air circulating oven at 160 ° C. for 1 hour and fired. After cooling, the ferrite powder bulk was crushed using a sieve shaker equipped with a 106- and 75-micron screen mesh to obtain a resin-coated carrier.

[0081]

The toner of the present invention has a relatively small variation in the charge amount due to environmental variations, and has sufficient heat-resistant storage properties and fixing strength. Further, the toner of the present invention can be efficiently produced with relatively low energy.

[Brief description of the drawings]

FIG. 1 is a graph illustrating a relationship between a grindability index (c) of a toner composition and a weight ratio (X) of a binder resin.

Continued on the front page (72) Inventor Yoshitaka Sekiguchi 2-13-13 Azuchicho, Chuo-ku, Osaka-shi, Osaka F-term in Osaka International Building Minolta Co., Ltd. (Reference) 2H005 AA01 AA06 AB04 CA03 CA05 EA06 EA07 EA10

Claims (9)

[Claims] 1. An electrostatic image development comprising at least a binder resin (A), a polymer (B) having a weight average molecular weight of 1,000 to 3,000 and a weight average molecular weight / number average molecular weight of 2.0 or less, and toner particles containing a colorant. (1) a> 1.0 and a>b; and / or (2) a> b and c <a ^X · b ^1-X (where a is a crushing property of the binder resin (A)) Index, b is the crushing index of the polymer (B), c is the kneaded toner material,
The crushability index of the toner composition obtained by cooling,
Is a weight ratio of the binder resin (A) to the total amount of the binder resin (A) and the polymer (B)). 2. The electrostatic image developing toner according to claim 1, wherein the pulverizability index (B) of the polymer (B) is 0.8 or less. 3. The polymer (B) comprises an aromatic monomer and / or
3. The electrostatic image developing toner according to claim 1, wherein the toner is a homopolymer or a copolymer of an aliphatic monomer. 4. The aromatic monomer is one or more monomers selected from the group consisting of styrene, vinyltoluene, α-methylstyrene, isopropenyltoluene and indene, and the aliphatic monomer is isoprene, piperylene, 4. The electrostatic image developing toner according to claim 3, wherein the toner is one or more monomers selected from the group consisting of methyl-butene-1 and 2-methylbutene-2. 5. The electrostatic image developing toner according to claim 1, wherein the polymer (B) contains at least styrene and / or α-methylstyrene. 6. The polymer (B) has a weight average molecular weight of 1,000 to 200.
6. The electrostatic image developing toner according to claim 1, wherein the toner is polystyrene. 7. The polymer (B) has a weight average molecular weight of 2,000 to 280.
6. The toner for developing an electrostatic image according to claim 1, wherein the toner is poly-α-methylstyrene of 0. 8. The polymer (B) has a weight average molecular weight of 1800 to 250.
6. The toner for developing an electrostatic image according to claim 1, wherein the toner is α-methylstyrene-isopropenyltoluene copolymer or α-methylstyrene-isopropenyltoluene-isoprene copolymer. 9. The polymer (B) is a binder resin (A) 100
9. The electrostatic image developing toner according to claim 1, wherein the toner is contained in an amount of 1 to 25 parts by weight based on parts by weight.