JPH09265209A - Resin composition for toner and toner - Google Patents

Abstract

(57) [Summary] [Problem] Toner resin composition having excellent low-temperature fixability, a wide fixing temperature range, and capable of obtaining a sufficiently stable image even when copying using a high-speed type or small-sized electronic copying machine. And toner. A resin composition for a toner of the present invention comprises a low molecular weight vinyl polymer component having a weight average molecular weight of 3 × 10 ^{3 to} 5 × 10 ^{4 and} a high molecular weight of 3 × 10 ^{5 to} 5 × 10 ⁶ . 0.05 to 1 part of an antioxidant is contained in 100 parts by weight of a vinyl polymer containing a vinyl polymer component as a main component. With this toner resin composition as the main component,
This is melt-kneaded, then cooled and finely pulverized to obtain the toner of the present invention.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for toner used in electrophotography and the like, and more specifically to a resin composition for toner used in a dry developing method in a method of developing an electrostatic image. The thing and the toner.

[0002]

2. Description of the Related Art In electrophotography and the like, a dry developing system is often used as a method for developing an electrostatic charge image. In this dry development method, triboelectrically-charged toner (development) is prepared by mixing a carrier such as iron powder or glass beads with a fine powder containing a colorant such as carbon black and other additives in a toner resin serving as a binder. Agent) is used.

In order to obtain a copy, an electrostatic latent image is usually formed on a photoconductor, and triboelectrically-charged toner is electrically attached to the electrostatic latent image to develop it. The toner image is transferred onto a sheet such as a sheet of paper and then fixed by a hot-pressing roller having releasability to the toner to form a permanent visible image.

This type of toner mainly has anti-offset property (the toner adheres to a heat-pressing roller for fixing and does not stain the paper) and low-temperature fixability (the toner firmly adheres to the paper at low temperature). In addition, it is required to have various properties such as blocking resistance (toner particles do not aggregate).

The toner having improved offset resistance, low-temperature fixing property and blocking resistance as described above is composed of a low molecular weight vinyl polymer component and a high molecular weight vinyl polymer component. A resin composition in which the polymer component is at least one polymer selected from the group consisting of styrene polymers, (meth) acrylic acid ester polymers and styrene- (meth) acrylic acid ester polymers The toner that has been used is widely known (for example, JP-A-56-158340).

[0006]

However, although the above-mentioned conventional toners have good offset resistance, low-temperature fixing property and blocking resistance, they are used in high-speed type and small-sized electronic copying machines, which are in high demand in recent years. When copying by copying, the above performances are not always sufficiently satisfactory.

That is, when copying is performed using a high-speed type or small-sized electronic copying machine, it is particularly necessary that the toner is easily melted with a small amount of heat, and in particular, a toner having further improved low temperature fixability is required. To be done. This is also preferable from the viewpoint of energy saving of the electronic copying machine. However, with conventional toner, the temperature at which offset (double image) occurs decreases when attempting to improve low temperature fixability,
It is becoming difficult to balance such low-temperature fixability with offset resistance and blocking resistance.

The present invention solves the problems of such conventional toners, and its purpose is to:
Excellent low-temperature fixability, anti-offset property and anti-blocking property, especially excellent low-temperature fixability, wide fixing temperature range, and sufficiently stable image quality even when copying using a high-speed type or small electronic copying machine. Another object of the present invention is to provide a resin composition for a toner and a toner capable of obtaining the above image.

[0009]

[Means for Solving the Problems] The above object is to provide a low molecular weight vinyl polymer component having a weight average molecular weight of 3 × 10 ^{3 to} 5 × 10 ^{4 and} a high molecular weight of 3 × 10 ^{5 to} 5 × 10 ⁶ . A resin composition for a toner containing 0.05 to 1 part of an antioxidant in 100 parts by weight of a vinyl polymer containing a vinyl polymer component as a main component, and a resin composition for a toner as a main component, This can be achieved by a toner obtained by melt-kneading, cooling and pulverizing.

The low molecular weight and high molecular weight vinyl polymer components used in the present invention are not particularly limited, but like the conventional resin compositions for toners and toners, styrene monomers and (meth) acrylic acid esters are used. Polymers or copolymers having both a system monomer or a styrene monomer and a (meth) acrylic acid ester monomer as a constituent unit are preferably used.

Here, as the styrene-based monomer, styrene, o-methylstyrene, m-methylstyrene, p-
Methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, pt-butylstyrene, pn-hexylstyrene, pn-octylstyrene, p- n-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, p-methoxystyrene, p-phenylstyrene,
Examples thereof include p-chlorostyrene, 3,4-dichlorostyrene, divinylbenzene and the like. Particularly, styrene is preferable.

As the (meth) acrylic acid ester type monomer, methyl acrylate, ethyl acrylate, propyl acrylate, n-butyl acrylate, isobutyl acrylate, n-octyl acrylate, dodecyl acrylate, (Meth) such as 2-ethylhexyl acrylate, stearyl acrylate, methyl methacrylate, ethyl methacrylate, propyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, n-octyl methacrylate, dodecyl methacrylate, stearyl methacrylate.
Mention may be made of alkyl esters of acrylic acid.
In particular, methyl methacrylate, n-butyl acrylate, n-butyl methacrylate, and 2-ethylhexyl methacrylate are preferable.

Other (meth) acrylic acid ester monomers include 2-chloroethyl acrylate, phenyl acrylate, α-chloromethyl acrylate, phenyl methacrylate, dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and methacrylic acid. Examples thereof include 2-hydroxyethyl acid, glycidyl methacrylate, bisglycidyl methacrylate, polyethylene glycol dimethacrylate, and methacryloxyethyl phosphate.

In the present invention, the low molecular weight vinyl polymer component has a weight average molecular weight of 3 × 10 ^{3 to} 5 × 10 5.
Must be in the range of ⁴ . Further, the high molecular weight vinyl polymer component has a weight average molecular weight of 3 × 10 ^{5 to} 5 ×.
It must be in the range of 10 ⁶ . Here, the weight average molecular weight is a weight average molecular weight measured by gel permeation chromatography (GPC) (using a monodisperse polystyrene standard sample).

Weight average of the above-mentioned low molecular weight vinyl polymer component
Average molecular weight is 3 × 10^ThreeBelow, the toner's anti-blocking
On the contrary, the weight average molecular weight is 5 ×.
10 ⁶If the temperature exceeds, the fixing temperature of the toner becomes high and the temperature becomes low.
Fixability deteriorates. On the other hand, the above high molecular weight vinyl polymer
Weight average molecular weight of the component is 3 × 10^FiveBelow the toner
Offset resistance is poor, and conversely the weight average molecular weight is 5
× 10⁶If the temperature exceeds the above, the fixing temperature of the toner will become high and low.
The heat fixability deteriorates. Especially low molecular weight vinyl polymer
Weight average molecular weight of 8 x 10^Three~ 2 x 10^FourRange
And the weight average molecular weight of the high molecular weight vinyl polymer component is 5
× 10^Five~ 2 x 10⁶Those in the range are preferred.

Further, when the amount of the low molecular weight vinyl polymer component increases and the amount of the high molecular weight vinyl polymer component decreases, the offset resistance of the toner deteriorates, and conversely, the low molecular weight vinyl polymer component decreases, When the amount of the high molecular weight vinyl polymer component is large, the low temperature fixability of the toner is deteriorated. Therefore, the ratio of the low molecular weight vinyl polymer component to the high molecular weight vinyl polymer component is in the range of 95 to 70% by weight of the low molecular weight vinyl polymer and 5 to 30% by weight of the high molecular weight vinyl polymer component. Some are preferable, and more preferably 90 to 80% by weight of a low molecular weight vinyl polymer,
It is 10 to 20% by weight of a high molecular weight vinyl polymer component.

Furthermore, the low molecular weight vinyl-based polymer component and the high molecular weight vinyl-based polymer component are used in order to improve the blocking resistance of the toner, and both vinyl-based polymer components are measured by a differential scanning calorimeter (DSC). It is desirable that the glass transition point measured is 50 ° C. or higher.

The low molecular weight vinyl polymer component and the high molecular weight vinyl polymer component may be either non-crosslinked type or crosslinked type. Further, each vinyl-based polymer component may be a homopolymer or copolymer, or 2
One or more polymers or copolymers may be used. The low molecular weight vinyl polymer component and the high molecular weight vinyl polymer component may be compatible with each other to have a single phase structure, or may be incompatible with each other to have a phase separation structure.

Therefore, the resin composition for toner of the present invention comprises the low molecular weight vinyl polymer component having the specific weight average molecular weight and the high molecular weight vinyl polymer component having the specific weight average molecular weight as main components. The antioxidant is contained in an amount of 0.05 to 1 part by weight based on 100 parts by weight of the vinyl polymer. As the antioxidant, it is preferable to use a phenol-based antioxidant, a phosphorus-based antioxidant and a hindered amine-based antioxidant.

As the phenolic antioxidant, triethylene glycol-bis [3- (3-t-butyl-4-) is used.
Hydroxy-5-methylphenyl) propionate (IRGANOX 245 manufactured by Ciba-Geigy, Adeka Stab AO-70 manufactured by Asahi Denka Co., Ltd.), 2,4-bis- (n-octylthio) -6- (4-hydroxy-3,5 -Di-t-butyl alinino) -1,3,5-triazine (IRGANOX 565 manufactured by Ciba-Geigy), tetrakis [methylene-3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] Methane (IRGANOX manufactured by Ciba Geigy
1010, Adeka Stab AO-60 manufactured by Asahi Denka Co., Ltd., octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (IRGA manufactured by Ciba Geigy)
NOX 1076, Adeka Stab AO-50 manufactured by Asahi Denka Co., Ltd., tris- (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate (IRGANOX manufactured by Ciba Geigy)
3114, Adeka Stab AO-20 manufactured by Asahi Denka Co., Ltd., 1,
1,3-tris (2-methyl-4-hydroxy-5-t
-Butylphenyl) butane (Adeka Stub manufactured by Asahi Denka Co., Ltd.
AO-30, I. C. Toppan CA manufactured by Company I), 1, 3,
5-trimethyl-2,4,6-tris (3,5-di-t
-Butyl-4-hydroxybenzyl) benzene (Adeka Stab AO-300 manufactured by Asahi Denka Co., Ltd., IO manufactured by Shell Japan Co., Ltd.
NOX 330), 4,4′-butylidene-bis (3-methyl-6-t-butylphenol) (Adeka Stab AO-40 manufactured by Asahi Denka Co., Ltd., and Sumilizer BBM manufactured by Sumitomo Chemical Co., Ltd.). In particular, triethylene glycol-bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate (IRGA manufactured by Ciba-Geigy)
NOX245, Adeka Stab AO-70 manufactured by Asahi Denka Co., Ltd.) are preferred.

As the phosphorus-based antioxidant, tris-
(2,4-di-t-butylphenyl) phosphite (IRGAFOS 168 manufactured by Ciba-Geigy, Adeka Stab 2112 manufactured by Asahi Denka Co., Ltd.), octadecyl phosphite (Adeka Stab PEP-8 manufactured by Asahi Denka Co., Ltd.), cyclic Neopentanetetraylbis (2,6-di-t-butyl-4-
Methylphenyl) phosphite (Adeka Stab PEP-36 manufactured by Asahi Denka Co., Ltd.), 2,2-methylenebis (4,6-
Examples thereof include di-t-butyl-4-methylphenyl) octyl phosphite (Adeka Stab HP-10 manufactured by Asahi Denka Co., Ltd.) and the like.

As the hindered amine type antioxidant,
Poly [{6- (1,1,3,3-tetramethylbutyl)
Amino-1,3,5-triazine-2,4-diyl}
{(2,2,6,6-tetramethyl-4-piperidyl)
Imino-hexamethylene} {(2,2,6,6-tetramethyl-4-piperidyl) imino}] (CHIMASSORB 944 manufactured by Ciba-Geigy), N, N′-bi (3-aminoropyr) ethylenediamine / 2,2 4-Bis [N-butyl-N- (1,2,2,6,6-pentamethyl-4-piperidyl) amino] -6-chloro-1,3,5-triazine condensate (CHIMASSORB 119 manufactured by Ciba Geigy) Etc.).

These antioxidants may be used alone or in admixture of two or more. When the content of the antioxidant is less than 0.05 parts by weight based on 100 parts by weight of the vinyl polymer mainly composed of the low molecular weight vinyl polymer component and the high molecular weight vinyl polymer component, the antioxidant is If the effect of the present invention cannot be obtained by the agent and conversely the content of the antioxidant exceeds 1 part by weight, the vinyl polymer and the antioxidant are separated from each other, and the blocking resistance of the toner is adversely affected. . In particular, the content of the antioxidant is preferably 0.1 to 0.5 parts by weight.

The low molecular weight vinyl polymer component and the high molecular weight vinyl polymer component can be obtained by suspension polymerization, emulsion polymerization, solution polymerization or bulk polymerization. Then, in order to obtain a vinyl polymer having a low molecular weight vinyl polymer component and a low molecular weight vinyl polymer component as main components, (1) a low molecular weight vinyl polymer component and a low molecular weight vinyl polymer component And (2) a low molecular weight vinyl polymer component and a high molecular weight vinyl polymer component are mixed and dissolved in an organic solvent such as toluene, and (3) a high molecular weight vinyl polymer component. Is dissolved in an organic solvent such as toluene, a vinyl-based monomer that gives a low molecular weight vinyl-based polymer component is dissolved therein, and this monomer is polymerized.

In particular, in order to more homogeneously disperse the high molecular weight vinyl polymer component and the low molecular weight vinyl polymer component in the resin composition and to exert their performance sufficiently, the above (2) and The method (3) is preferable, and the method (3) is more preferable.

In order to add an antioxidant to the vinyl polymer thus obtained, for example, a vinyl polymer containing a low molecular weight vinyl polymer component and a low molecular weight vinyl polymer component as main components is used. After obtaining the coalescence, a method in which a predetermined amount of an antioxidant is added to the organic solvent solution of the vinyl polymer to uniformly dissolve it, and then the organic solvent is removed is suitably adopted.

Thus, the toner resin composition of the present invention is obtained. In addition, the resin composition for a toner of the present invention has a colorant, a charge control agent, and other conventional additives for a toner, such as an auxiliary agent for improving low-temperature fixability (higher alcohol) that melts at 50 to 80 ° C. in advance. , Higher fatty acids, higher fatty acid esters, etc.) and the like.

In order to produce the toner of the present invention using the above-mentioned resin composition for toner, for example, the resin composition for toner obtained by the above-mentioned method is colored with a color control agent, other charge control agents, and other conventional materials. A method is used in which an additive for toner is blended, melted and kneaded using a roll mill, a kneader, an extruder or the like, cooled, and finely pulverized. When a toner resin composition is preliminarily mixed with a toner additive such as a colorant or a charge control agent, these toner additives are not necessary. Cooling after the melt-kneading is usually performed to a temperature near room temperature. The crushing may be room temperature crushing,
Low temperature crushing may be used. In addition, usually, after finely pulverizing, the particles are classified to adjust the particle size to a certain range.

As the colorant, pigments or dyes such as carbon black, chrome yellow, aniline blue and the like which are commonly used in toners of this type are used. As the charge control agent, a dye control agent such as a dye such as nigrosine or spirone black (produced by Hodogaya Chemical Co., Ltd.) or a phthalocyanine pigment is used. Further, polypropylene wax and low molecular weight polyethylene which have a releasing action on the fixing roller of the copying machine may be blended, and in addition, aliphatic amide, bisaliphatic amide, metal soap, paraffin and the like may be blended. .

Further, in order to improve the fluidity of the toner particles, hydrophobic silica or the like may be added later. Further, in order to obtain a magnetic toner, magnetic powder made of iron or zinc such as magnetite, ferrite or hematite, or an alloy or compound showing ferromagnetism such as zinc, cobalt, nickel or manganese may be mixed.

In the resin composition for toner and toner, polyester resin, polyether resin, xylene resin, epoxy resin, butyral resin, coumarone indene resin, terpene resin, hydrocarbon resin,
A small amount of a known binder resin other than a vinyl polymer such as a petroleum resin may be blended.

(Function) As a binder resin for toner,
Low molecular weight vinyl polymer component having a weight average molecular weight of 3 × 10 ^{3 to} 5 × 10 ⁴ and weight average molecular weight of 3 × 10 ^{5 to} 5 × 10
^{When a} vinyl-based polymer containing ⁶ high-molecular-weight vinyl-based polymer components as a main component is used, mainly due to the action of these low-molecular weight and high-molecular weight vinyl-based polymer components, offset resistance and low-temperature fixing A toner having excellent properties and blocking resistance can be obtained. Moreover, when 0.05 to 1 part of the antioxidant is contained with respect to 100 parts by weight of the vinyl-based polymer, the low-temperature fixability is improved without substantially lowering the offset resistance and blocking resistance of the toner. It is further improved.

The reason for this is presumed as follows. That is, in order to obtain a toner using a vinyl-based polymer (resin composition for toner) containing a low-molecular weight vinyl-based polymer component and a high-molecular-weight vinyl-based polymer component as main components, this toner resin composition is usually used. If necessary, colorants, charge control agents,
A method in which other conventional toner additives are blended, melt-kneaded using a roll mill, a kneader, an extruder or the like, cooled, and pulverized is employed.

At this time, it was found that the above-mentioned kneading caused a decrease in the molecular weight of the vinyl polymer, and particularly a large decrease in the molecular weight of the high molecular weight vinyl polymer component contributing to the improvement of the offset resistance. Therefore, in consideration of such a decrease in the molecular weight, if an excessive amount of the high molecular weight vinyl polymer component is blended than usual, the excessive amount of the high molecular weight vinyl polymer component causes the fixing temperature of the toner to increase. The decline is hindered.

When a desired amount of antioxidant is contained in the vinyl polymer (resin composition for toner), the molecular weight of the vinyl polymer during kneading is lowered by the action of the antioxidant. The decrease in the molecular weight of the high molecular weight vinyl polymer component is suppressed, and the offset resistance of the toner can be improved without adding an excessive amount of the high molecular weight vinyl polymer component than usual. As a result, it is presumed that the blending amount of the high molecular weight vinyl polymer component that contributes to the improvement of the offset resistance can be reduced, the lower temperature fixing can be performed, and the fixing temperature range can be widened.

[0036]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples and comparative examples of the present invention will be described below. Example 1 Production of Resin Composition for Toner A spiral stirrer, a reflux condenser, a nitrogen introducing tube, and a thermocouple for temperature measurement were attached to a 3 liter cylindrical reaction vessel, and 100 parts by weight of toluene and 1 of the weight average molecular weight were attached thereto. 100 parts by weight of styrene-methyl methacrylate-n-butyl acrylate copolymer (component ratio: 70% by weight / 10% by weight / 20% by weight), styrene having a weight average molecular weight of 500,000-
Methyl methacrylate copolymer (component ratio: 80% by weight /
20% by weight) and then heated to the boiling point of toluene while purging with nitrogen, and with the toluene boiling, 4
It was maintained for a time to dissolve.

The weight average molecular weight of each of the above copolymers was measured by the gel permeation chromatography (GPC) method using the following measuring device. Apparatus 510 type high pressure pump manufactured by Waters Company 410 type differential refractometer (IR type detector) column manufactured by Waters Company Shodex KF-80M 2 units manufactured by Showa Denko KK Shodex KF-802.5M 1 unit Measurement temperature 40 ° C Sample Solution 0.2 wt% tetrahydrofuran solution Injection volume 100 μl

Then, the above solution was cooled to room temperature, and triethylene glycol-bis [3- (3-t-butyl-5-methyl-4-hydroxyphenyl) propionate (manufactured by Ciba Geigy) was added as an antioxidant. IRGANO
X 245) (0.25 parts by weight) was added, and the mixture was stirred for 20 minutes to form a uniform solution. Then, the reflux condenser was removed, a decompression device was attached, and the mixture was heated to 140 to 170 ° C. to distill off toluene to obtain a resin composition for toner comprising the above two copolymers and an antioxidant. The glass transition point of this toner resin composition was 58 ° C. The glass transition point was measured with a differential scanning calorimeter (DSC).

Manufacture of Toner 100 parts by weight of the above resin composition for toner, 6 parts by weight of carbon black (MA-100: manufactured by Mitsubishi Kasei), 1 part by weight of Spiron Black TRH (manufactured by Hodogaya Chemical Co., Ltd.),
3 parts by weight of polypropylene wax (Viscole 660P: manufactured by Sanyo Kasei Co., Ltd.) were melt-kneaded in a roll mill, cooled, coarsely pulverized, finely pulverized in a jet mill and classified to obtain a toner powder having an average particle size of about 11 μm.

Evaluation of Toner Performance With respect to the above toner, the low temperature fixing property of the toner and the storage stability of the toner were evaluated by the following methods. As a result, the fixing temperature range is 140 to 200 ° C. (or higher), which is excellent in low-temperature fixability.
The fixing temperature range was wide. Further, the storage stability of the toner was good (toner sieve passage rate 99%).

<Low-Temperature Fixing Property of Toner> 4 parts by weight of toner and 96 parts by weight of iron powder carrier having an average particle diameter of about 50 to 80 μm are uniformly mixed to prepare a developer, and the developer is used as follows. Then, the fixing temperature and the offset generation temperature were measured.

In the fixing test, copying is performed by changing the set temperature of the heat-pressing roller for fixing of the electrophotographic copying machine stepwise, and no offset (double image) is generated. When the density of the copied image was less than 10% when rubbed with an eraser, the fixability was determined to be good, and the range was set as the fixing temperature range. The electrophotographic copying machine used was a VIVACE 310 manufactured by Fuji Xerox Co., Ltd.
It is modified so that the temperature of the hot pressing roller for fixing can be changed within a range of about 100 to 200 ° C.

<Storage stability of toner> 5 g of toner is 50
After storing in a 50 ml sample bottle and leaving it in a constant temperature bath at 50 ° C for 8 hours, the toner is passed through a sieve with a mesh opening of 250 μm, and the toner storage stability is good when the toner passage rate is 95% or more. And

Example 2 A 3 liter cylindrical reaction vessel was equipped with a spiral stirrer, a reflux condenser, a nitrogen inlet tube, and a thermocouple for temperature measurement. To this, 100 parts by weight of toluene and styrene having a weight average molecular weight of 8,000 were attached. n-Butyl acrylate-hydroxyethyl methacrylate copolymer (component ratio: 70% by weight / 10% by weight)
/ 20% by weight) 100 parts by weight, and 15 parts by weight of a styrene-n-butyl acrylate copolymer having a weight average molecular weight of 1,000,000 (component ratio: 90% by weight / 10% by weight) are added to the boiling point of toluene while purging with nitrogen. The mixture was heated and kept in the boiling state of toluene for 4 hours to be dissolved.

Thereafter, the above solution was cooled to room temperature and triethylene glycol-bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate (manufactured by Ciba Geigy) was added as an antioxidant. IRGANO
X 245) 0.1 part by weight and Tris- (2,4-di-t-)
Butylphenyl) phosphite (IR manufactured by Ciba Geigy)
GAFOS 168) 0.1 part by weight was added and stirred for 20 minutes to form a uniform solution. Then, the reflux condenser was removed, a decompression device was attached, and the mixture was heated to 140 to 170 ° C. to distill off toluene to obtain a resin composition for toner comprising the above two copolymers and an antioxidant. The glass transition point of this resin composition for toner was 60 ° C.

A toner was obtained in the same manner as in Example 1 except that this resin composition for toner was used. The toner fixing temperature range was 130 to 200 ° C. (or higher), the low temperature fixing property was excellent, and the fixing temperature range was wide. In addition, the storage stability of the toner is good (toner sieve passage rate 99%).
Met.

Example 3 A 3 liter cylindrical reaction vessel was equipped with a spiral stirrer, a reflux condenser, a nitrogen inlet tube, and a thermocouple for temperature measurement. To this, 100 parts by weight of toluene and styrene having a weight average molecular weight of 8,000 were attached. n-Butyl acrylate copolymer (component ratio: 80
% By weight / 20% by weight) 100 parts by weight, weight average molecular weight 1
Add 15 parts by weight of 1,000,000 styrene-n-butyl acrylate copolymer (component ratio: 90% by weight / 10% by weight), heat to the boiling point of toluene while purging with nitrogen, and maintain for 4 hours in a state where toluene is boiling And dissolved.

Thereafter, the above solution was cooled to room temperature, and octadecyl-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate (IRGANOX 1076, manufactured by Ciba-Geigy) was used as an antioxidant. 0.3 parts by weight was added and stirred for 20 minutes to form a uniform solution. After that, remove the reflux condenser and attach a decompression device to 140-170 ° C.
The mixture was heated to 1, toluene was distilled off, and a resin composition for toner comprising the above-mentioned two kinds of copolymers and an antioxidant was obtained. The glass transition point of this resin composition for toner was 57 ° C.

A toner was obtained in the same manner as in Example 1 except that this toner resin composition was used. The toner fixing temperature range was 125 to 200 ° C. (or higher), the low temperature fixing property was excellent, and the fixing temperature range was wide. Also, the storage stability of the toner is good (toner sieve passage rate 97%).
Met.

Comparative Example 1 A toner was obtained in the same manner as in Example 1 except that no antioxidant was used. This toner fixing temperature range is 1
The fixing temperature range was narrow at 40 to 170 ° C. The storage stability of the toner is good (toner passage rate 9
9%).

Comparative Example 2 20 parts by weight of a styrene-methyl methacrylate copolymer having a weight average molecular weight of 500,000 (component ratio: 80% by weight / 20% by weight) was changed to 30 parts by weight, and an antioxidant was used at all. A toner was obtained in the same manner as in Example 1 except that no toner was used. The toner fixing temperature range is 160 to 200 ° C.
The fixing temperature was high. In addition, the storage stability of the toner was good (toner sieving rate 99%).

Comparative Example 3 Triethylene glycol-bis [3-, which is an antioxidant
(3-t-butyl-5-methyl-4-hydroxyphenyl) propionate (IRGANOX 245 manufactured by Ciba-Geigy)
) A toner was obtained in the same manner as in Example 1 except that 0.25 parts by weight was changed to 0.02 parts by weight. The toner fixing temperature range was 140 to 170 ° C. and the fixing temperature range was narrow. In addition, the storage stability of the toner was good (toner sieving rate 99%).

The results of each Example and each Comparative Example are summarized in Table 1 above.

[0054]

[Table 1]

From Table 1 above, it is possible to reduce the compounding amount of the high molecular weight vinyl polymer component which contributes to the improvement of the offset resistance by adding an appropriate amount of the antioxidant, and to achieve further low temperature fixing. It can be seen that the fixing temperature range is widened and a toner having a good balance of low-temperature fixability, offset resistance and blocking resistance can be obtained.

[0056]

The resin composition for a toner and the toner of the present invention are constituted as described above, and are thereby excellent in offset resistance, low temperature fixing property and blocking resistance,
In particular, it is excellent in low-temperature fixability, has a wide fixing temperature range, and a sufficiently stable high-quality image can be obtained even when copying using a high-speed type or small-sized electronic copying machine.

Therefore, the resin composition for a toner and the toner of the present invention can sufficiently meet the increasing demands in recent years, such as high speed copying, downsizing, and energy saving.

Claims (2)

[Claims] 1. A weight average molecular weight of 3 × 10 ^{3 to} 5 × 10 ^4.
Low molecular weight vinyl polymer component and weight average molecular weight 3 × 1
Toner characterized by containing 0.05 to 1 part of an antioxidant in 100 parts by weight of a vinyl polymer mainly composed of a high molecular weight vinyl polymer component of 0 ^{5 to} 5 × 10 ^6. Resin composition. 2. A toner obtained by using the resin composition for a toner according to claim 1 as a main component, melt-kneading the mixture, cooling it, and pulverizing it.