JPH11143126A - Binder resin for toner and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner which is excellent in non-offset property and fixing property and has excellent heat deterioration resistance. SOLUTION: In a binder resin containing a styrene-acrylic copolymer as a main component, a binder resin 100 is used.
A binder resin for toner containing 0.1 to 2 parts by weight of an antioxidant based on part by weight and a method for producing the same.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder resin for toner used for developing an electrostatic image or a magnetic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like, and a method for producing the same. More specifically, the present invention relates to a binder resin for a toner, which is capable of providing a toner having excellent non-offset properties and fixing properties, and excellent heat deterioration resistance.

[0002]

2. Description of the Related Art In a typical image forming process by an electrophotographic method or an electrostatic printing method, a photoconductive insulating layer is uniformly charged, the insulating layer is exposed, and then a charge on an exposed portion is obtained. To form an electric latent image by dissipating the toner, and a developing step of visualizing the latent image by adhering a finely charged toner to the latent image, and transferring the obtained visible image to a transfer material such as transfer paper. It comprises a transfer step of transferring and a fixing step of permanently fixing by heating or pressing.

Various performances are required for the toner and the binder resin for the toner used in the electrophotographic method or the electrostatic printing method in each of the above steps. For example, in the development process, the toner and the binder resin for the toner maintain a charge amount suitable for a copying machine without being affected by the surrounding environment such as temperature and humidity in order to attach the toner to the electric latent image. I have to do it. Also,
In the fixing step by the heat roller fixing method, the non-offset property that does not adhere to the heat roller and the fixability to paper must be good. Further, it is required to have a blocking resistance so that the toner does not block during storage in a copying machine.

Conventionally, binder resins for toners include:
Styrene-acrylic resins are frequently used, and linear (non-crosslinked) resins and crosslinked resins are used. In the case of a cross-linking type binder resin for toner,
Attempts have been made to broaden the molecular weight distribution by cross-linking the resin to improve the fixability and non-offset properties of the toner. Further, in a linear type toner binder resin, a high molecular weight polymer component and a low molecular weight polymer component are mixed to control the glass transition temperature and the molecular weight of both components, and the molecular weight distribution (Mw / Mn)
Attempts have been made to improve the fixability and non-offset property of the toner by controlling the image quality.

[0005]

However, in such a toner using a styrene-acrylic resin as a binder resin, the styrene-acrylic resin has low heat resistance, so that the styrene-acrylic resin is not kneaded in the production of the toner. The non-offset properties of the toner are reduced and the odor is generated due to the thermal decomposition of styrene and the styrene-acrylic resin partially reduced in molecular weight due to thermal degradation in the fixing section of a copying machine or printer. Had. Accordingly, an object of the present invention is to provide a binder resin for toner having excellent non-offset properties and fixing properties, and having excellent heat deterioration resistance.

[0006]

Means for Solving the Problems In view of such a situation, the present inventors have conducted intensive studies on a binder resin for a toner, and as a result, a specific oxidation of a binder resin containing a styrene-acrylic copolymer as a main component has been carried out. The inventors have found that the addition of an inhibitor can improve the heat resistance of the toner, thereby achieving the present invention. That is, in the binder resin for a toner of the present invention, an antioxidant is used in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the binder resin in the binder resin containing a styrene-acrylic copolymer as a main component.
It is characterized by containing by weight. The binder resin for a toner of the present invention has a weight average molecular weight (Mw) and a number average molecular weight (M
n) and the ratio B (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the binder resin after heat history at 200 ° C. for 4 hours. , And the following expressions (1) and (2) are satisfied.

[0007]

## EQU3 ## B / A ≧ 0.6 (1)

[0008]

B ≧ 15 (2) Further, in the method for producing a binder resin for a toner according to the present invention, an antioxidant is used for 100 parts by weight of a monomer mixture for producing a styrene-acrylic copolymer. To 0.1
It is characterized in that a mixture containing 2 parts by weight is subjected to radical polymerization.

In the present invention, by adding a specific amount of an antioxidant, it is possible to maintain the excellent non-offset properties and fixing properties inherent in a styrene-acrylic copolymer as a binder resin while maintaining the excellent styrene-acrylic properties. The present invention has been able to suppress the thermal deterioration of the system copolymer and solve the problems of non-offset property reduction and odor generation accompanying the thermal deterioration.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The binder resin for a toner according to the present invention is characterized in that an antioxidant is contained in an amount of 0.1 to 2 parts by weight based on 100 parts by weight of the binder resin. The antioxidant used in the present invention is not particularly limited, but tris (2,4-di-t-butylphenyl) phosphite, bis (2,4-di-t-).
Butylphenyl) pentaerythritol-di-phosphine, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-phosphine, 2,
2-methylenebis (4,6-di-t-butylphenyl)
Octyl phosphite, 2,2-methylenebis [4-
(1,1,3,3-tetramethylbutyl) -6- (2H
-Benzotriazol-2-yl) phenol], 1,
3,5-Trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene or the like is preferable because it has a large effect of preventing the styrene-acrylic copolymer from being thermally degraded.

In the present invention, the antioxidant must be contained in the range of 0.1 to 2 parts by weight based on 100 parts by weight of the binder resin. It has a content of 0.
If the amount is less than 1 part by weight, the effect of preventing thermal deterioration of the styrene-acrylic copolymer is not sufficient, and if it exceeds 2 parts by weight, the charge stability of the toner tends to be impaired. 0.3 to 1.5 parts by weight, more preferably 0.5 to 1 part by weight.

The styrene-acrylic copolymer used as a main component of the binder resin for a toner of the present invention is a styrene-acrylic copolymer comprising a styrene monomer and a copolymerizable acrylic monomer. It is. In the present invention, styrene monomers used for the polymerization of the styrene-acrylic copolymer include styrene, o-
Methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene, 2,
4-dimethylstyrene, pn-butylstyrene, p-
tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-densylstyrene, pn-dodecylstyrene, p-phenylstyrene, 3,4- Examples thereof include dicyclosylstyrene, and among them, styrene is preferable. These styrene monomers can be used alone or in combination of two or more.

The copolymerizable acrylic monomers include ethyl acrylate, methyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate, and metaaryl. Acrylic acid esters such as acrylic acid, ethyl methacrylate, methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate, and stearyl methacrylate are exemplified. .

Further, unsaturated carboxylic acids such as acrylic acid, methacrylic acid and cinnamic acid; unsaturated dicarboxylic acid diesters such as dimethyl maleate, diethyl maleate, butyl maleate, dimethyl fumarate, diethyl fumarate and dibutyl fumarate; , Acrylic acid, methacrylic acid, unsaturated monocarboxylic acids such as cinnamic acid, maleic acid, fumaric acid, unsaturated dicarboxylic acids such as itaconic acid, monomethyl maleate, monoethyl maleate, monobutyl maleate, monomethyl fumarate, fumaric acid A carboxylic acid-containing vinyl monomer such as an unsaturated monocarboxylic acid monoester such as monoethyl and monobutyl fumarate can be used in combination.

Also, divinylbenzene, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4-butanediol di (meth) acrylate, 1,5-pentadiol di (meth) Acrylate, neopentyl di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate,
Tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolethane tri (meth) acrylate A crosslinking monomer such as trimethylolpropane tri (meth) acrylate can also be used in combination.

The copolymerization ratio of these monomers is not particularly limited, but is preferably selected so that the glass transition temperature of the obtained binder resin for toner is in the range of 40 ° C. or higher. This is because if the glass transition temperature of the binder resin for a toner is less than 40 ° C., the blocking occurrence temperature of the toner tends to decrease, and the storage stability tends to extremely decrease. More preferably, the temperature is in the range of 45 to 70 ° C. because the fixability of the toner tends to decrease.

In the polymerization of the binder resin for a toner of the present invention, an antioxidant is added to a monomer mixture for forming the styrene-acrylic copolymer as described above, and the polymerization is carried out. Polymerization of binder resin for toner
It can be carried out by a known polymerization method such as a suspension polymerization method, a solution polymerization method, an emulsion polymerization method, and a bulk polymerization method.However, there is no problem of odor due to a residual solvent, and it is easy to control heat generation, and the dispersant The suspension polymerization method is preferred in that the amount used is small and the moisture resistance is not impaired. In particular, the obtained styrene-acrylic copolymer is preferably composed of a homogeneously mixed high molecular weight polymer component and a low molecular weight polymer component, and suspension polymerization of the high molecular weight polymer component is performed. Then, the polymerization is preferably carried out by a polymerization method such as a two-stage suspension polymerization method in which the low-molecular-weight polymer component is subjected to suspension polymerization in the presence of suspended particles of the high-molecular polymer component.

Hereinafter, a method for producing a styrene-acrylic copolymer as a binder resin of the present invention by a two-stage suspension polymerization method will be specifically described. The suspension polymerization of the high molecular weight polymer component is not particularly limited, and can be performed according to a general suspension polymerization method, and is commonly used in the suspension polymerization together with the above-mentioned monomers. Dispersants, polymerization initiators, molecular weight regulators and the like can be used.

As a polymerization initiator used for suspension polymerization of a high molecular weight polymer component, a compound having three or more t-butyl peroxide groups in one molecule or a 10-hour half-life temperature of 90 to 140 ° C. A radical polymerization initiator having one functional group per molecule can be used. For example, as a compound having three or more t-butyl peroxide groups in one molecule, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane and the like can be mentioned. The 10-hour half-life temperature is 90-140.
Examples of the radical polymerization initiator having one functional group in one molecule at ° C include t-butyl peroxy laurate, t-butyl peroxy 3,5,5-trimethylhexanoate,
Cyclohexanone peroxide, t-butylperoxyisopropyl carbonate, t-butylperoxyacetate, t-butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, diisopropylbenzene hydroperoxide, di-t-butylperoxide Oxide, p-methane hydroperoxide, 2
-(Carbamoylazo) isobutyronitrile, 2,2-
Organic peroxides such as azobis (2,4,4-trimethylpentane) and 2-phenylazo-2,4-dimethyl-4-methoxyvaleronitrile, and azo compounds. These polymerization initiators can be used alone or in combination of two or more. The amount of the polymerization initiator used may be very small compared to the amount of the polymerization initiator used in the conventional suspension polymerization, and may be 0.001 to 0.5 parts by weight based on 100 parts by weight of all monomers. It is preferably used in the range of parts by weight, and more preferably in the range of 0.002 to 0.05 parts by weight.

Next, the low-molecular-weight copolymer is polymerized by suspension polymerization in the presence of the suspension-polymerized high-molecular-weight copolymer suspended particles. The suspension polymerization is not particularly limited, and can be carried out according to a general suspension polymerization method. For example, when the polymerization reaction rate of a high molecular weight polymer becomes about 10 to 90%, a low molecular weight It is preferable to start the polymerization by dissolving and adding the polymerization initiator for the polymer to water or the monomer for the low molecular weight polymer. When the low-molecular-weight polymer monomer is added, the content of the low-molecular-weight polymer component in the obtained toner binder resin is 30 to 8%.
It is preferable to add an amount so as to be in the range of 0% by weight.

The polymerization initiator used for suspension polymerization of the low molecular weight polymer component is not particularly limited.
Usually used peroxides and azo compounds having radical polymerizability can be used. For example, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, acetyl peroxide, isobutyryl peroxide Oxide, octanoyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-toluoyl peroxide, t-butylperoxyacetate, t-butylperoxide Oxyisobutyrate,
t-butyl peroxypiparate, t-butyl peroxy neodecanoate, cumyl peroxy neodecanoate, t-butyl peroxy 2-ethylhexanoate,
t-butyl peroxy 3,5,5-trimethylhexanoate, t-butyl peroxylylate, t-butyl peroxybenzoate, t-butyl peroxyisopropyl carbonate, azobisisobutyl nitrile, 2,
Examples thereof include 2-azobis- (2,4-dimethylvaleronitrile). Among them, octonyl peroxide, decanonyl, and the like, from the viewpoint of the persistence of the polymerization activity for the monomer and the completion of the polymerization in a relatively short time. Peroxide, lauroyl peroxide, benzoyl peroxide and m-trioil peroxide are preferred. These polymerization initiators can be used alone or in combination of two or more,
It is preferably used in the range of 0.1 to 10 parts by weight, more preferably 0.5 to 10 parts by weight, based on 100 parts by weight of the monomer.
The range is 10 parts by weight. The low molecular weight polymer component polymerized by suspension polymerization has a weight average molecular weight of 2,000 to
Preferably it is in the range of 50,000.

The suspension polymerization is preferably carried out with respect to the monomer.
10 to 10 times, more preferably about 2 to 4 times with water, adding a dispersant, a polymerization initiator, a dispersing aid or a chain transfer agent if necessary, and raising the temperature to a predetermined polymerization temperature, This is performed by continuing to heat until a predetermined polymerization rate is reached. Examples of the dispersant used in the suspension polymerization include polyvinyl alcohol, an alkali metal salt of a homopolymer or copolymer of (meth) acrylic acid, carboxytyl cellulose, gelatin, starch, barium sulfate, calcium sulfate, calcium carbonate, Examples thereof include magnesium carbonate and calcium phosphate. Among them, polyvinyl alcohol is preferable, and particularly preferable is partially saponified polyvinyl alcohol having an acetic acid group and a hydroxyl group in a block manner. These dispersants are used in an amount of 0.0
It is preferable to use it in the range of 1 to 5 parts by weight. If the amount of the dispersant is less than 0.01 part by weight, the stability of suspension polymerization is reduced, and the polymer tends to be solidified by aggregation of the produced particles, and conversely, the amount exceeds 5 parts by weight. This is because the toner tends to have a lower environmental dependency, particularly the moisture resistance, and the content is more preferably in the range of 0.05 to 2 parts by weight. If necessary, a dispersing aid such as sodium chloride, potassium chloride, sodium sulfate and potassium sulfate can be used together with these dispersants. further,
In order to adjust the molecular weight, a chain transfer agent such as n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, 2-ethylhexyl thioglycolate, α-methylstyrene dimer may be used, if necessary. .

The thus obtained binder resin for toner of the present invention has a weight average molecular weight (Mw) before heat history.
And the ratio A (Mw / Mn) of the number average molecular weight (Mn) to 2
Ratio of weight average molecular weight (Mw) and number average molecular weight (Mn) B (Mw / Mn) after heat history at 00 ° C. for 4 hours and before heat history
Is preferably 0.6 or more.
This is because if the B / A is less than 0.6, the change in the molecular weight of the binder resin during kneading at the time of kneading into a toner becomes large, and the non-offset property of the toner is lowered and lot fluctuation during the production of the toner is likely to occur. This is because there is a tendency, more preferably in the range of 0.62 or more, and more preferably in the range of 0.65 or more. Further, the ratio B (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) before applying the heat history at 200 ° C. for 4 hours to the binder resin for the toner is 15 or more. Is preferred.
This is because if Mw / Mn after the heat history is less than 15, a sufficient fixing temperature region as a toner tends to be not obtained, and more preferably 20 or more, more preferably 25 or more. This is the above range.

In the present invention, the styrene-acrylic copolymer is preferably contained as a binder resin in the toner in an amount of 80 to 97% by weight, more preferably 90 to 95% by weight. Range.
This is because when the content of the binder resin is less than 80% by weight, the non-offset property of the toner tends to decrease, and when it exceeds 97% by weight, the charging stability of the toner tends to deteriorate. is there.

The binder resin for toner of the present invention comprises a wax, a colorant, a pigment, a charge control agent, an offset preventing agent,
Along with additives such as magnetic powder, for example, using a kneader such as a twin-screw extruder or a mixer, kneading at a temperature about 15 to 30 ° C. higher than the softening temperature of the binder resin,
Classification is performed to form a toner. The obtained toner particles have an average particle size of about 5 to 20 μm, preferably about 8 to 15 μm, and preferably contain less than 3% by weight of fine particles having a particle size of 5 μm or less.

The waxes, colorants, pigments, charge control agents, anti-offset agents, and magnetic powders used may be those commonly used, for example, waxes such as low molecular weight polyolefin waxes such as polypropylene waxes (for toners). Used in the range of 0.5 to 5% by weight), carbon black, nigrosine dye, lamp black, Sudan black SM, navel yellow, mineral first yellow, lithol red, permanent orange 4R
Such as coloring agents or pigments such as nigrosine, alkyl group-containing azine dyes, basic dyes, monoazo dyes or metal complexes thereof, salicylic acid or metal complexes thereof, alkyl salicylic acid or metal complexes thereof, naphthoic acid or metal complexes thereof, etc. Examples include a control agent, an anti-offset agent such as polyethylene, polypropylene, and ethylene-polypropylene copolymer, and a magnetic powder such as ferrite and magnetite.

[0027]

The present invention will be specifically described below with reference to examples. In the examples, the fixing temperature range (non-malleability) was adjusted by using a fixing tester capable of freely changing the fixing temperature of the obtained toner at a fixing speed of 130 mm /.
The fixing was performed at a fixing pressure of 20 Kg for 2 seconds. At that time, the degree of contamination of the fixing roller by the toner was visually determined, and the evaluation was made based on the minimum temperature at which contamination starts and the maximum fixing temperature at which no contamination occurs.

The charge stability of the obtained toner was measured by blowing off the toner for 120 minutes, and the change in the charge amount was evaluated according to the following criteria. ：: The charge stability is excellent. Δ: The charging stability is slightly inferior. X: Charging stability is low.

The odor was determined by taking 10 g of the obtained toner into a glass dish and leaving it in a dryer at 50 ° C. for 2 hours to evaluate the odor according to the following criteria. ：: No particular odor is felt. Δ: Slight odor is felt. X: Strong odor.

The molecular weight (Mw, Mn) of the resin solution of 0.04% by weight using THF as a solvent was filtered through a PTFE membrane (Myshodisyk H-25-5 manufactured by Tosoh Corporation), and the solution was filtered into three columns (Tosoh Corporation). Was measured at a temperature of 38 ° C. by gel permeation chromatography (HCL-8020 manufactured by Tosoh Corporation) composed of TSKgel / GMH _XL column manufactured by KK, and F2000 / F700 / F288 / F128 /
It was determined in terms of polystyrene by a calibration curve using F80 / F40 / F20 / F2 / A1000 (polystyrene manufactured by Tosoh Corporation) and a styrene monomer. The measurement temperature was 38 ° C., and the detector was RI.

Example 1 To a monomer mixture consisting of 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) was used as a polymerization initiator. Propane (Parkadox 12 manufactured by Kayaku Akzo)
0.4 parts by weight were dissolved, and 200 parts by weight of deionized water and partially saponified polyvinyl alcohol (Nippon Synthetic Chemical Industry Co., Ltd.
After stirring and adding the mixture to 0.2 parts by weight of phenol (GH-23), the suspension was heated to 90 ° C. for 10 hours to carry out suspension polymerization of the high molecular weight polymer component. Thereafter, styrene 8 was added to the dispersion of the high molecular weight polymer component cooled to 40 ° C.
A monomer mixture consisting of 0 parts by weight and 20 parts by weight of n-butyl acrylate, and 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphate (HP available from Asahi Denka Co., Ltd.) as an antioxidant. -10) 0.5 parts by weight and 7 parts by weight of benzoyl peroxide as a polymerization initiator are added,
The temperature was raised to 130 ° C., and suspension polymerization of the low molecular weight polymer component was performed for 3 hours. Thereafter, the mixture is cooled to room temperature, sufficiently washed, dehydrated, and dried, and a styrene-acrylic copolymer in which a high molecular weight polymer component and a low molecular weight polymer component are uniformly mixed at a ratio of approximately 50:50. A coalescence was obtained. Mw of the obtained styrene-acrylic copolymer was 299000, and Mw / Mn was 40.2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours, and Mw and Mw / Mn (B) after the heat treatment and a ratio (B / A) of Mw / Mn before and after the heat history were measured. The results are shown in Table 1.

The obtained styrene-acrylic copolymer 9
3 parts by weight of carbon black (Mitsubishi Kasei Co. # 40)
5 parts by weight, 1 part by weight of a charge control agent for negative charging ("Bontron S-34" manufactured by Orient Chemical Industry Co., Ltd.) and 1 part by weight of a polyolefin wax (660P manufactured by Sanyo Kasei Co., Ltd.) were blended and melt-kneaded, and then 200C For 4 hours.
Next, after coarse pulverization was performed, the powder was pulverized to 15 μm or less using a jet mill pulverizer, and classified to remove 5 μm fine powder to obtain a toner. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Example 2 Example 1 was repeated except that bis (2,4-di-t-butylphenyl) pentaerythritol diphosphine (PEP-24G manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant. Similarly, a styrene-acrylic copolymer and a toner were obtained. Mw of the obtained styrene-acrylic copolymer
Was 299000 and Mw / Mn was 40.2. The obtained styrene-acrylic copolymer was heated at 200 ° C.
Heat treatment for 4 hours, and Mw, Mw / Mn after heat treatment
(B) and the ratio (B / A) of Mw / Mn before and after the heat history were measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Example 3 As an antioxidant, bis (2,6-di-tert-butyl-4) was used.
-Methylphenyl) pentaerythritol-di-phosphine (PEP-36 manufactured by Asahi Denka Co., Ltd.)
A styrene-acrylic copolymer and a toner were obtained in the same manner as in Example 1. Mw of the obtained styrene-acrylic copolymer was 299000, and Mw / Mn was 40.
It was 2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours.
w / Mn (B) and the ratio of Mw / Mn before and after thermal history (B
/ A) was measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Example 4 Tris (2,4-di-t-butylphenyl) phosphite (MARK2112 manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant.
A styrene-acrylic copolymer and a toner were obtained in the same manner as in Example 1 except for using. Mw of the obtained styrene-acrylic copolymer was 299000,
Mw / Mn was 40.2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours,
The Mw and Mw / Mn (B) after the heat treatment and the ratio (B / A) of Mw / Mn before and after the heat history were measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Example 5 Example 2 was repeated except that 1 part by weight of 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite (HP-10, manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant. Example 1
In the same manner as in the above, a styrene-acrylic copolymer and a toner were obtained. M of the obtained styrene-acrylic copolymer
w was 299000 and Mw / Mn was 40.2. The obtained styrene-acrylic copolymer was heated at 200 ° C.
Heat treatment for 4 hours, and Mw, Mw / Mn after heat treatment
(B) and the ratio (B / A) of Mw / Mn before and after the heat history were measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Example 6 The procedure of Example 6 was repeated except that 1 part by weight of bis (2,4-di-t-butylphenyl) pentaerythritol-di-phosphine (PEP-24G manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant. A styrene-acrylic copolymer and a toner were obtained in the same manner as in Example 1. Mw of the obtained styrene-acrylic copolymer was 299000, and Mw / Mn was 40.2.
Met. The obtained styrene-acrylic copolymer was mixed with 2
Heat treatment at 00 ° C. for 4 hours, Mw, Mw after heat treatment
/ Mn (B) and the ratio of Mw / Mn before and after thermal history (B /
A) was measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Example 7 As an antioxidant, bis (2,6-di-tert-butyl-4) was used.
A styrene-acrylic copolymer and a toner were obtained in the same manner as in Example 1 except that 1 part by weight of (-methylphenyl) pentaerythritol-di-phosphine (PEP-36 manufactured by Asahi Denka Co., Ltd.) was used. Mw of the obtained styrene-acrylic copolymer was 299000, and Mw / Mn
Was 40.2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours, and Mw and Mw / Mn (B) after the heat treatment and Mw / Mn before and after the heat history.
Was measured (B / A), and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Example 8 Tris (2,4-di-t-butylphenyl) phosphite (MARK2112 manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant.
Was used in the same manner as in Example 1 except that 1 part by weight of was used to obtain a styrene-acrylic copolymer and a toner. Mw of the obtained styrene-acrylic copolymer is 299000
And Mw / Mn was 40.2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours, and Mw and Mw / Mn (B) after the heat treatment and a ratio (B / A) of Mw / Mn before and after the heat history were measured. The results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Comparative Example 1 Except that 0.05 parts by weight of 2,2-methylenebis (4,6-di-t-butylphenyl) octyl phosphite (HP-10 manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant. In the same manner as in Example 1, a styrene-acrylic copolymer and a toner were obtained. Mw of the obtained styrene-acrylic copolymer was 299000, and Mw / Mn was 40.2.
Met. The obtained styrene-acrylic copolymer was mixed with 2
Heat treatment at 00 ° C. for 4 hours, Mw, Mw after heat treatment
/ Mn (B) and the ratio of Mw / Mn before and after thermal history (B /
A) was measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

COMPARATIVE EXAMPLE 2 As an antioxidant, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphine (PEP-24G manufactured by Asahi Denka Co., Ltd.) was used in an amount of 0.05 part by weight. In the same manner as in Example 1, a styrene-acrylic copolymer and a toner were obtained. Mw of the obtained styrene-acrylic copolymer was 299000, and Mw / Mn was 4
0.2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours.
w, Mw / Mn (B) and the ratio (B / A) of Mw / Mn before and after the thermal history were measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Comparative Example 3 As an antioxidant, bis (2,6-di-tert-butyl-4) was used.
(Methylphenyl) pentaerythritol-di-phosphine (PEP-36 manufactured by Asahi Denka Co., Ltd.) was used in the same manner as in Example 1 except that 0.05 part by weight was used to obtain a styrene-acrylic copolymer and a toner. . Styrene obtained
The Mw of the acrylic copolymer is 299000, and the Mw is
/ Mn was 40.2. The obtained styrene-acrylic copolymer is subjected to a heat treatment at 200 ° C. for 4 hours, and Mw and Mw / Mn (B) after the heat treatment and Mw before and after the heat history are measured.
/ Mn ratio (B / A) was measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Comparative Example 4 Tris (2,4-di-t-butylphenyl) phosphite (MARK2112 manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant.
Styrene-acrylic copolymer and toner were obtained in the same manner as in Example 1 except that 0.05 part by weight of was used.
Mw of the obtained styrene-acrylic copolymer is 299
000 and Mw / Mn was 40.2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours, and Mw and Mw / Mn (B) after the heat treatment and a ratio (B / A) of Mw / Mn before and after the heat history were measured. The results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Comparative Example 5 Tris (2,4-di-t-butylphenyl) phosphite (MARK2112 manufactured by Asahi Denka Co., Ltd.) was used as an antioxidant.
Was used in the same manner as in Example 1 except that 5 parts by weight of was used to obtain a styrene-acrylic copolymer and a toner. Mw of the obtained styrene-acrylic copolymer is 299000
And Mw / Mn was 40.2. The obtained styrene-acrylic copolymer was subjected to a heat treatment at 200 ° C. for 4 hours, and Mw and Mw / Mn (B) after the heat treatment and a ratio (B / A) of Mw / Mn before and after the heat history were measured. The results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

Comparative Example 6 A styrene-acrylic copolymer and a toner were obtained in the same manner as in Example 1 except that no antioxidant was used. Mw of the obtained styrene-acrylic copolymer is 2
Mw / Mn was 40.2. The obtained styrene-acrylic copolymer is subjected to a heat treatment at 200 ° C. for 4 hours, and Mw and Mw / Mn (B) after the heat treatment.
The Mw / Mn ratio (B / A) before and after the heat history was measured, and the results are shown in Table 1. The obtained toner was evaluated for fixing temperature range, charging stability and odor, and the results are shown in Table 1.

[0046]

[Table 1]

[0047]

According to the toner composition of the present invention, a styrene-acrylic copolymer is used as a binder resin and an antioxidant is contained, whereby the styrene-acrylic copolymer is used.
An object of the present invention is to provide a toner which can suppress thermal deterioration of an acrylic copolymer, is excellent in non-offset properties and fixing properties, and has excellent heat deterioration resistance.

Claims (3)

[Claims] A binder resin comprising a styrene-acrylic copolymer as a main component, wherein the binder resin
A binder resin for a toner, comprising 0.1 to 2 parts by weight of an antioxidant based on part by weight. 2. The ratio A (Mw / Mw) between the weight average molecular weight (Mw) and the number average molecular weight (Mn) of the binder resin before heat history.
Mn) and the ratio B (Mw / Mn) of the weight average molecular weight (Mw) to the number average molecular weight (Mn) of the binder resin after thermal history at 200 ° C. for 4 hours are represented by the following equations (1) and (1). 2)
A binder resin for a toner, characterized by satisfying the following. [Expression 1] B / A ≧ 0.6 (1) [Expression 2] B ≧ 15 (2) 3. A toner comprising radically polymerizing a mixture containing 0.1 to 2 parts by weight of an antioxidant with respect to 100 parts by weight of a monomer mixture for producing a styrene-acrylic copolymer. Of binder resin for plastics.