JPH08234481A - Resin binder for toner - Google Patents

Abstract

PURPOSE: To obtain a resin binder ensuring well-balanced fixability and anti- offsetting property of a toner by using a high mol.wt. polymer component having a specified mol.wt. distribution. CONSTITUTION: This resin binder is styrene-acrylic resin consisting of a high mol.wt. polymer component and a low mol.wt. polymer component, and the high mol.wt. polymer component has at least two peaks or shoulders on the higher mol.wt. side of the main peak mol.wt. in its mol.wt. distribution by gel permeation chromatography. The high and low mol.wt. polymer components have been uniformly mixed and each of the polymers is made of styrene-acrylic resin made of a polymer or copolymer of a styrene monomer, other copolymerizable vinyl monomer, etc. This styrene-acrylic resin is produced by a known polymn. method such as suspension polymn., soln. polymn., emulsion polymn. or bulk polymn.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a binder resin for toner used in electrophotography, electrostatic printing, and the like, and more specifically, a toner having a wide molecular weight distribution of high molecular weight polymer components The present invention relates to a binder resin for toner which is excellent in fixing property and offset resistance.

[0002]

2. Description of the Related Art A typical image forming process using electrophotography or electrostatic printing is to uniformly charge a photoconductive insulating layer, expose the insulating layer, and then charge the exposed portion. To form an electrical latent image by dissipating the latent image, and visualized by attaching a fine powder toner having an electric charge to the latent image, the obtained visible image on 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.

As the toner and the binder resin for the toner used in such an electrophotographic method or electrostatic printing method, various performances are required in each of the above steps. For example, in the developing process, the toner and the binder resin for the toner retain the charge amount suitable for the 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 process using the heat roller fixing method, the offset resistance that does not adhere to the heat roller and the fixability on paper must be good. Further, blocking resistance that toner does not block during storage in a copying machine is also required.

Conventionally, as a resin for toner, styrene-
Acrylic resins are often used, and linear type resins and crosslinked type resins are used. In a linear type resin, it has been attempted to improve the fixing property and non-offset property of the toner by mixing a high molecular weight polymer and a low molecular weight polymer. However, a toner using such a resin, for example, when the fixing property is improved,
Since the melt viscosity of the resin is lowered and the offset resistance of the toner is lowered, it is difficult to obtain a toner having a good balance between the two. Therefore, attempts have been made to improve the balance between fixability and offset resistance by broadening the molecular weight distribution of the resin.

[0005]

SUMMARY OF THE INVENTION For example, Japanese Patent Publication No. 63-
32182, JP-B-63-32183, JP-B-63-32382, and JP-B-3-48506 disclose a high molecular weight polymer having a specific molecular weight distribution and a low molecular weight polymer. A method is proposed in which the resin is mixed to broaden the molecular weight distribution of the resin and improve the balance between the fixability and the offset resistance. However, merely mixing a high molecular weight polymer and a low molecular weight polymer was not sufficient and satisfactory in fixing property and offset resistance. Therefore, an object of the present invention is to have a wide molecular weight distribution containing a high molecular weight polymer component and a low molecular weight polymer component, and a toner binder having a well-balanced fixing property and non-offset property. To provide a resin.

[0006]

In view of such circumstances, the inventors of the present invention have made earnest studies on the molecular weight distribution of the high molecular weight polymer component of the binder resin for toner, and as a result, have found that the high molecular weight polymer having a specific molecular weight distribution. The present invention has been found to be able to provide a binder resin for a toner having a well-balanced fixing property and non-offset property of the toner by using the combined component.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION That is, the binder resin for toner of the present invention is a styrene-acrylic resin composed of a high molecular weight polymer component and a low molecular weight polymer component, and has a molecular weight distribution by gel permeation chromatography. In the above, it has at least two peaks or shoulders on the high molecular weight side of the main peak molecular weight of the high molecular weight polymer component.

The binder resin for toner of the present invention is a mixture of a high molecular weight polymer component and a low molecular weight polymer component uniformly, and both polymers are styrene monomers and other copolymerizable vinyl monomers. It is made of a styrene-acrylic resin made of a polymer or a copolymer made of a polymer. In the present invention, as the styrenic monomer used for the polymerization of the high molecular weight polymer component and the low molecular weight polymer component,
Styrene, o-methylstyrene, m-methylstyrene,
p-methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-
Nonyl styrene, pn-densyl styrene, pn-
Dodecyl styrene, p-phenyl styrene, 3,4-dichloro styrene, etc. are mentioned, Especially, styrene is preferable. These styrenic monomers may be used alone or in 2
It can be used in combination of more than one species.

Other copolymerizable vinyl monomers include ethyl acrylate, methyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate. , Unsaturated carboxylic acids such as methacrylic acid, ethyl methacrylic acid, methyl methacrylic acid, n-butyl methacrylic acid, isobutyl methacrylic acid, propyl methacrylic acid, 2-ethylhexyl methacrylic acid and stearyl methacrylic acid Examples thereof include esters, unsaturated dicarboxylic acid diesters such as dimethyl maleate, diethyl maleate, butyl maleate, dimethyl fumarate, diethyl fumarate, and dibutyl fumarate.

Further, unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and cinnamic acid, unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, monomethyl maleate, monoethyl maleate, monobutyl maleate and fumaric acid. By using in combination with a carboxylic acid group-containing vinyl monomer such as unsaturated monocarboxylic acid monoester such as monomethyl, monoethyl fumarate, monobutyl fumarate, etc., it is possible to obtain a better balance between fixability and offset resistance as a toner. A binder resin can be obtained.

The copolymerization ratio of these monomers is not particularly limited, but it is preferable that the glass transition temperature of the obtained resin is 50 ° C. or higher. this is,
This is because when the glass transition temperature of the resin is lower than 50 ° C, the storage stability may be extremely lowered when it is made into a toner, and more preferably in the range of 55 to 70 ° C. The high molecular weight polymer component constituting the binder resin for toner of the present invention has a weight average molecular weight (Mw) of 1 × 10 ⁵ to 1.
It is preferably in the range of 5 × 10 ⁶ . This is because when the weight average molecular weight (Mw) is less than 1 × 10 ⁵ , the offset resistance as a toner tends to decrease, and when it exceeds 1.5 × 10 ⁶ , the fixability as a toner decreases. This is because it tends to occur, and more preferably 3 × 10
It is in the range of ⁵ to 8 × 10 ⁵ .

The low molecular weight polymer component preferably has a weight average molecular weight of 3 × 10 ³ to 2 × 10 ⁵ . This is because when the weight average molecular weight is less than 3 × 10 ³ , the mechanical strength of the resin is lowered and the toner tends to be in an excessively pulverized state when electrification occurs, and fogging tends to occur in the image. This is because if it exceeds 10 ⁵ , the fixability as a toner tends to be lowered, and the range of 6 × 10 ³ to 1 × 10 ⁵ is more preferable. In the present invention, the ratio of the high molecular weight polymer component and the low molecular weight polymer component is not particularly limited, but the high molecular weight polymer component is preferably contained in the range of 10 to 50% by weight. . This is because if the high molecular weight polymer component is less than 10% by weight, the non-offset property as a toner tends to be poor, and conversely if it exceeds 50% by weight, the fixability as a toner tends to be poor. .

The binder resin for a toner comprising the styrene-acrylic resin of the present invention has a main peak of each of a low molecular weight polymer component and a high molecular weight polymer component in a chromatogram measured by gel permeation chromatography. And the main peak of the low molecular weight polymer component exists in the region of the molecular weight of 1 × 10 ^{3 to} 3 × 10 ⁴ , and the main peak of the high molecular weight polymer component has the molecular weight of 5 ×.
It is preferably present in the region of 10 ⁴ to 8 × 10 ⁵ ,
More preferably, the main peak of the low molecular weight polymer component has a molecular weight of 2 × 10 ³ to 2 × 10 ⁴ , and the main peak of the high molecular weight polymer component has a molecular weight of 1 × 10 ^{5 to} 6 × 10 ^5.
Exist in the area of. This is because if the main peak of the low molecular weight polymer component is present in the region where the molecular weight is less than 1 × 10 ³ , the mechanical strength of the resin decreases and the toner becomes over-pulverized when electrification occurs, which easily causes fog in the image. This is because the toner tends to deteriorate, and conversely, when it exists in a region exceeding 3 × 10 ⁴ , the fixability as a toner tends to decrease. Further, when the main peak of the high molecular weight polymer component is present in a region having a molecular weight of less than 5 × 10 ⁴ , the offset resistance as a toner tends to be lowered, and conversely, when it is present in a region exceeding 8 × 10 ⁵ , it becomes a toner. This is because the fixing property of is likely to decrease.

Further, the binder resin for toner of the present invention has a higher molecular weight distribution than that of the main peak of the high molecular weight polymer component in the molecular weight distribution of the high molecular weight polymer component in the chromatogram measured by gel permeation chromatography. It is important to have at least two peaks or shoulders on the molecular weight side. This is because by having at least two peaks or shoulders on the high molecular weight side of the main peak of the high molecular weight polymer component, it is possible to broaden the molecular weight distribution of the high molecular weight polymer component and improve the fixability as a toner. It is possible to remarkably improve the balance with the offset resistance. In the present invention, at least one of at least two peaks or shoulders present on the higher molecular weight side than the molecular weight of the main peak of the high molecular weight polymer component has at least one of the peaks, that is, the fixing property as a toner and the offset resistance. It is preferable from the viewpoint of improving the balance with the property.

The peaks or shoulders other than the main peak of the high molecular weight polymer component have a molecular weight of 1 × 10 ^{5 to} 3 ×.
It is preferably present in the region of 10 ⁶ and more preferably in the region of 1.5 × 10 ⁵ to 2 × 10 ⁶ . This is because when the peaks or shoulders other than the main peak of the high molecular weight polymer component are present in the region where the molecular weight is less than 1 × 10 ⁵ , the offset resistance as a toner tends to decrease, and conversely, the molecular weight This is because if it exists in a region exceeding 3 × 10 ⁶ , the dispersibility of the colorant, charge control agent, etc., added at the time of forming a toner tends to decrease. Further, in the present invention, peaks or shoulders other than the main peak of the high molecular weight polymer component are 1 in the region of molecular weight 1 × 10 ⁵ to 1 × 10 ^{6 and} the region of molecular weight 1 × 10 ^{6 to} 3 × 10 ⁶ , respectively. It is preferable that there are one or more, more preferably a region having a molecular weight of 3 × 10 ^{5 to} 6 × 10 ⁵ and a molecular weight of 1 × 1.
One or more of each exists in the region of 0 ^{6 to} 1.8 × 10 ⁶ .

The styrene-acrylic copolymer which is the binder resin for the toner of the present invention can be prepared by the above-mentioned styrene-based monomer by a known polymerization method such as suspension polymerization method, solution polymerization method, emulsion polymerization method and bulk polymerization method. It can be produced by polymerizing a copolymer or other copolymerizable vinyl monomer. Among them, the suspension polymerization method is particularly preferable because it does not have a problem of odor due to the residual solvent because a solvent is not used, heat generation is easily controlled, the amount of the polymerization dispersant used is small, and the moisture resistance is not impaired. Polymerization by the suspension polymerization method is carried out by charging the above-mentioned monomer and a polymerization initiator into a closed container at a temperature of 95 ° C.
Under the above conditions, suspension polymerization of the high molecular weight polymer component is performed, and then suspension polymerization of the low molecular weight polymer component is performed at a temperature of 95 ° C or higher in the presence of suspended particles of the high molecular weight polymer component. Is preferred.

As the polymerization initiator used for suspension polymerization of the high molecular weight polymer component, a compound having three or more t-butylperoxide groups in one molecule or a 10-hour half-life temperature of 90 to 140 ° C. It is possible to use a radical polymerization initiator having one functional group in one molecule. For example, 2,2-bis (4,4-di-t-butylper-oxycyclohexyl) propane and the like can be mentioned as a compound having three or more t-butylper-oxide groups in one molecule. The 10-hour half-life temperature is 90 to 140.
As a radical polymerization initiator having one functional group in one molecule at 0 ° C., t-butylperoxylaurate, t-butylperoxy 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-
Examples thereof include 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 kinds. The amount of the polymerization initiator used may be a very small amount as compared with the amount of the polymerization initiator used in the conventional suspension polymerization, and 0.001 to 0.5 parts by weight based on 100 parts by weight of all the monomers. It is preferably used in the range of parts, and more preferably 0.002 to 0.05 parts by weight. This is because the amount of polymerization initiator used is 0.00
When it is less than 1 part by weight, it tends to take a long time to reach a predetermined polymerization reaction rate, and when it exceeds 0.5 part by weight, the molecular weight of the high molecular weight polymer component tends not to be sufficiently high. Is.

In the present invention, a polyfunctional vinyl monomer may be used as a crosslinking agent in an amount of 0.05 parts by weight or less, more preferably 0.002 parts by weight, based on 100 parts by weight of all monomers. Is in the range of 0.02 parts by weight. This is because when the amount of the polyfunctional vinyl monomer used exceeds 0.05 parts by weight, the low molecular weight polymer component and the high molecular weight polymer component tend not to be uniformly mixed. Examples of the polyfunctional vinyl monomer used include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, ethylene glycol di (meth) acrylate,
Triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, bisphenol A derivative Examples thereof include systematic di (meth) acrylates, which can be used alone or in combination of two or more kinds. Among them, divinylbenzene and 1,3-butylene glycol di (meth) acrylate are particularly preferable.

In the present invention, the above-mentioned polymerization initiator or cross-linking agent is used, and the high molecular weight polymer component is polymerized by suspension polymerization at a high temperature of 95 ° C. or higher, preferably 100 ° C. or higher. As a result, the polymerization initiator is efficiently consumed and the weight average molecular weight is 3 × 10 5.
^It is as high as ⁵ or more, and a high molecular weight polymer component having a specific molecular weight distribution can be obtained in a short time of about 1 to 3 hours. When the polymerization temperature is lower than 95 ° C, it tends to take a long time to reach a predetermined polymerization reaction rate. The suspension polymerization of the low molecular weight polymer component is not particularly limited, and for example, the polymerization reaction rate of the high molecular weight polymer is 10 to 90.
It is preferable to start the polymerization by dissolving the polymerization initiator for the low molecular weight polymer in water or the monomer for the low molecular weight polymer and adding it at the time when the amount becomes about%. When the low molecular weight polymer monomer is added, it is preferable to add such an amount that the content of the low molecular weight polymer component of the obtained resin is in the range of 50 to 90% by weight.

The polymerization initiator used for suspension polymerization of the low molecular weight polymer component is not particularly limited,
Commonly used radically polymerizable peroxides and azo compounds can be used, and examples thereof include di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, acetyl peroxide and isobutyryl peroxide. Oxide, octanonyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-trimethylhexanoyl peroxide, benzoyl peroxide, m-toluoyl peroxide, t-butylperoxyacetate, t-butylperoxide Oxyisobutyrate,
t-butyl peroxypiperate, t-butyl peroxy neodecanoate, cumyl peroxy neodecanoate, t-butyl peroxy 2-ethylhexanoate,
t-butyl peroxy 3,5,5-trimethylhexanoate, t-butyl peroxy lylate, t-butyl peroxy benzoate, t-butyl peroxy isopropyl cavonate, azobisisobutyl nitrile, 2,
2-azobis- (2,4-dimethylvaleronitrile) and the like can be mentioned, but among them, octanonyl peroxide and decanoyl peroxide are preferable from the viewpoint of the sustainability of the polymerization activity for the monomers and the fact that the polymerization is completed in a relatively short time. Peroxide, lauroyl peroxide, benzoyl peroxide and m-trioyl peroxide are preferred. These polymerization initiators can be used alone or in combination of two or more kinds,
The monomer is preferably used in the range of 0.1 to 10 parts by weight, more preferably 0.5 to 100 parts by weight.
It is in the range of 10 parts by weight.

In the present invention, the suspension polymerization is preferably carried out in a proportion of 1 to 10 times, more preferably 2 to 4 times, that of the monomer together with a dispersant, a polymerization initiator and, if necessary, a dispersion aid. Agent or chain transfer agent is added, the temperature is raised to a predetermined polymerization temperature, and heating is continued until a predetermined polymerization rate is reached.

Examples of dispersion stabilizers used in suspension polymerization include polyvinyl alcohol, alkali metal salts of homopolymers or copolymers of (meth) acrylic acid, carboxytyl cellulose, gelatin, starch, barium sulfate,
Calcium sulfate, calcium carbonate, magnesium carbonate,
Examples thereof include calcium phosphate and the like. Among them, polyvinyl alcohol is preferable, and partially saponified polyvinyl alcohol in which an acetic acid group and a hydroxyl group are present in a block manner is particularly preferable. These dispersants are based on 100 parts by weight of water.
It is preferably used in the range of 0.01 to 5 parts by weight.
This is because when the amount of the dispersant used is less than 0.01 part by weight, the stability of suspension polymerization is lowered and the polymer tends to solidify due to the aggregation of the produced particles, and conversely exceeds 5 parts by weight. This is because the environmental dependency of the toner, particularly the humidity resistance tends to decrease, and the range of 0.05 to 2 parts by weight is more preferable. Also, if necessary, together with these dispersants, sodium chloride, potassium chloride, sodium sulfate,
A dispersion aid such as potassium sulfate can also be used in combination. Further, in order to adjust the molecular weight, n-octyl mercaptan, n-dodecyl mercaptan, t-
A chain transfer agent such as dodecyl mercaptan, 2-ethylhexyl thioglycolate, or α-methylstyrene dimer may be used.

The toner binder resin thus obtained has a softening temperature of 110 to 170 ° C. and a glass transition temperature of 40 to 80 ° C., and the toner has fixability and non-offset property. It is preferable in terms of storage stability, fluidity and the like.

[0024]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, the glass transition temperature was determined by the DSC method (heating rate 10 ° C./min) after the sample was heated to 100 ° C. and melt-quenched. For the softening temperature, a flow tester (CFT-500 manufactured by Shimadzu Corporation) having a nozzle of 1 mmφ × 10 mm was used, and a load of 30 was used.
Under the conditions of Kgf and a temperature rising rate of 3 ° C./min, the temperature when ½ of the sample amount flows out is shown. Weight average molecular weight and molecular weight distribution, tetrahydrofuran as a solvent,
It was measured using gel permeation chromatography (HCL-8020 manufactured by Tosoh Corporation), and determined by polystyrene conversion.

The fixability is determined by using a fixing tester capable of freely changing the fixing temperature and fixing speed of 130 mm / sec.
When the pressure was 40 kg, cellophane tape was attached to the fixed toner image, and the change in image density before and after peeling when the cellophane tape was peeled off was visually observed and evaluated according to the following criteria. ◯: Small change in image density X: Significant change in image density

The offset resistance is determined by using a fixing tester capable of freely changing the fixing temperature and fixing speed of 130 m.
The degree of contamination by the toner of the fixing roller was visually observed at m / sec and a pressure of 40 kg, and evaluated according to the following criteria. ◎: Almost no pollution ○: Little pollution ×: Significant pollution

The storage stability was evaluated by visually observing the blocking state after the toner was placed in a hot air dryer kept at about 50 ° C. and left for 50 hours according to the following criteria. ⊚: No blocking ◯: Some blocking occurred ×: Blocking was remarkable.

Moisture resistance is determined by the charge amount after standing for about 20 hours in an environment of temperature 30 ° C. and humidity of 85% and the charge amount after standing for about 20 hours in an environment of temperature 10 ° C. and humidity 15%. Then, the presence or absence of the environmental dependency was evaluated according to the following criteria. ◯: Almost no environmental dependence ×: Significant environmental dependence

Example 1 41.5 parts by weight of styrene, n-butyl acrylate 8.5
As a polymerization initiator, 2 parts by weight of a monomer mixture is added.
2-bis (4,4-di-t-butylperoxycyclohexyl) propane ("Parkadox 1" manufactured by Kayaku Akzo Co., Ltd.
2 ") 0.02 part by weight is dissolved, and 200 parts by weight of deionized water and 0.2 part by weight of partially saponified polyvinyl alcohol (" Gosenol GH-23 "manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) Add to the mixture and stir. Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 1 hour. The polymerization reaction rate at this time was about 60%. Further, styrene 4 was added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C.
1.5 parts by weight, 8.5 parts by weight of n-butyl acrylate, 6 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate ("Perbutyl Z" manufactured by NOF CORPORATION) were added, The temperature was raised to 130 ° C. and suspension polymerization of the low molecular weight polymer was performed for 1.5 hours. The polymerization reaction rate at this time is about 9
It was 9%. Then, it was cooled to room temperature, sufficiently washed with water, dehydrated and dried to obtain a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed. Table 1 shows the softening temperature, glass transition temperature, weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component of the obtained binder resin for toner.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industry Co., Ltd.) and polypropylene wax. (Sanyo Kasei Co., Ltd. "660P") 1 part by weight is kneaded for about 5 minutes at 150 ° C. using a twin-screw extruder, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 to 15 μm. Toner was obtained. Table 2 shows the evaluation results of the fixability, offset resistance, storage stability and moisture resistance of the obtained toner.

Example 2 41.5 parts by weight of styrene, n-butyl acrylate 8.5
As a polymerization initiator, 2 parts by weight of a monomer mixture is added.
2-bis (4,4-di-t-butylperoxycyclohexyl) propane ("Parkadox 1" manufactured by Kayaku Akzo Co., Ltd.
2 ") 0.02 part by weight, 0.01 part by weight of divinylbenzene as a cross-linking agent, and 200 parts by weight of deionized water and partially saponified polyvinyl alcohol (" Gosenol GH "manufactured by Nippon Synthetic Chemical Industry Co., Ltd. -23 ") 0.2 part by weight in a mixture and stirred. Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 1 hour. The polymerization reaction rate at this time was about 60%. Furthermore, styrene 41.5 was added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C.
Parts by weight, 8.5 parts by weight of n-butyl acrylate, 6 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate ("Perbutyl Z" manufactured by NOF Corporation) are added, and the mixture is heated to 130 ° C. The temperature was raised and suspension polymerization of the low molecular weight polymer was carried out for 1.5 hours. The polymerization reaction rate at this time is about 100%
Met. After that, cool to room temperature, wash thoroughly with water,
After dehydration and drying, a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed was obtained. Table 1 shows the softening temperature, glass transition temperature, weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component of the obtained binder resin for toner.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industry Co., Ltd.), and polypyrro 1 part by weight of pyrene wax (“660P” manufactured by Sanyo Kasei Co., Ltd.) was kneaded with a twin-screw extruder at 150 ° C. for about 5 minutes, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 A toner of ˜15 μm was obtained. Table 2 shows the evaluation results of the fixability, offset resistance, storage stability and moisture resistance of the obtained toner.

Example 3 41.5 parts by weight of styrene, n-butyl acrylate 8.5
As a polymerization initiator, 2 parts by weight of a monomer mixture is added.
2-bis (4,4-di-t-butylperoxycyclohexyl) propane ("Parkadox 1" manufactured by Kayaku Akzo Co., Ltd.
2 ") 0.02 parts by weight, 0.025 parts by weight of divinylbenzene as a cross-linking agent are dissolved, 200 parts by weight of deionized water and partially saponified polyvinyl alcohol (" Gosenol GH "manufactured by Nippon Synthetic Chemical Industry Co., Ltd. -23 ") 0.2 part by weight in a mixture and stirred. Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 1 hour. The polymerization reaction rate at this time was about 50%. Furthermore, styrene 41.5 was added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C.
Parts by weight, 8.5 parts by weight of n-butyl acrylate, 6 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate ("Perbutyl Z" manufactured by NOF Corporation) are added, and the mixture is heated to 130 ° C. The temperature was raised and suspension polymerization of the low molecular weight polymer was carried out for 1.5 hours. The polymerization reaction rate at this time is about 100%
Met. After that, cool to room temperature, wash thoroughly with water,
After dehydration and drying, a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed was obtained. Table 1 shows the softening temperature, glass transition temperature, weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component of the obtained binder resin for toner.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Co., Ltd.) and polypropylene wax. (Sanyo Kasei Co., Ltd. "660P") 1 part by weight is kneaded for about 5 minutes at 150 ° C. using a twin-screw extruder, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 to 15 μm. Toner was obtained. Table 2 shows the evaluation results of the fixability, offset resistance, storage stability and moisture resistance of the obtained toner.

Example 4 41.5 parts by weight of styrene, n-butyl acrylate 8.5
To the monomer mixture consisting of parts by weight, t-as a polymerization initiator
Butyl peroxybenzoate (“Perbutyl Z” manufactured by NOF CORPORATION) 0.03 parts by weight and 0.01 parts by weight of divinylbenzene as a cross-linking agent were dissolved, and 200 parts by weight of deionized water and partially saponified polyvinyl alcohol ( 0.2 g by weight of "Gosenol GH-23" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and stirred. Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 2 hours. The polymerization reaction rate at this time was about 66%. Further, in a dispersion liquid of a high molecular weight polymer cooled to 40 ° C., styrene 41.
5 parts by weight, 8.5 parts by weight of n-butyl acrylate, 6 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate (“Perbutyl Z” manufactured by NOF CORPORATION) were added, and the mixture was heated to 130 ° C. The temperature was raised to 1.5 and suspension polymerization of the low molecular weight polymer was performed for 1.5 hours. The polymerization reaction rate at this time is about 99%
Met. After that, cool to room temperature, wash thoroughly with water,
After dehydration and drying, a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed was obtained. Table 1 shows the softening temperature, glass transition temperature, weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component of the obtained binder resin for toner.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Co., Ltd.) and polypropylene wax. (Sanyo Kasei Co., Ltd. "660P") 1 part by weight is kneaded for about 5 minutes at 150 ° C. using a twin-screw extruder, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 to 15 μm. Toner was obtained. Table 2 shows the evaluation results of the fixability, offset resistance, storage stability and moisture resistance of the obtained toner.

Example 5 41.5 parts by weight of styrene, n-butyl acrylate 8.5
To the monomer mixture consisting of parts by weight, t-as a polymerization initiator
0.03 parts by weight of butyl peroxybenzoate (“Perbutyl Z” manufactured by NOF CORPORATION) and 0.025 parts by weight of divinylbenzene as a crosslinking agent were dissolved, and 200 parts by weight of deionized water and partially saponified polyvinyl alcohol ( 0.2 g by weight of "Gosenol GH-23" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and stirred. Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 2 hours. The polymerization reaction rate at this time was about 50%. Further, styrene 4 was added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C.
1.5 parts by weight, 8.5 parts by weight of n-butyl acrylate, 6 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate ("Perbutyl Z" manufactured by NOF CORPORATION) were added, The temperature was raised to 130 ° C. and suspension polymerization of the low molecular weight polymer was performed for 1.5 hours. The polymerization reaction rate at this time is about 1
00%. Then, it was cooled to room temperature, sufficiently washed with water, dehydrated and dried to obtain a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed. Table 1 shows the softening temperature, glass transition temperature, weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component of the obtained binder resin for toner.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industry Co., Ltd.) and polyprorylene. 1 part by weight of wax (“660P” manufactured by Sanyo Kasei Co., Ltd.) was kneaded with a twin-screw extruder at 150 ° C. for about 5 minutes, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 A toner having a thickness of 15 μm was obtained, and the evaluation results of the fixability, offset resistance, storage stability, and moisture resistance of the obtained toner are shown in Table 2.

Example 6 41.75 parts by weight of styrene, n-butyl acrylate 7.
A monomer mixture consisting of 5 parts by weight and 0.75 parts by weight of methacrylic acid was added to 2,2-bis (4,4) as a polymerization initiator.
-Di-t-butylperoxycyclohexyl) propane ("Parkadox 12" manufactured by Kayaku Akzo Co., Ltd.) was dissolved in 0.03 parts by weight, and 200 parts by weight of deionized water and partially saponified polyvinyl alcohol (Nippon Synthetic Chemistry) were used. "Goseno" manufactured by Kogyo Co., Ltd.
GH-23 ") 0.2 part by weight and stirred. Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 2 hours. The polymerization reaction rate at this time was about 70%. Further, in a dispersion of the high molecular weight polymer cooled to 40 ° C., 44.25 parts by weight of styrene, 5 parts by weight of n-butyl acrylate, 0.75 parts by weight of methacrylic acid, 5 parts by weight of benzoylperoxide and t- 1 part by weight of butyl peroxybenzoate ("Per-Butyl Z" manufactured by NOF CORPORATION) was added, the temperature was raised to 130 ° C, and suspension polymerization of the low molecular weight polymer was carried out for 1.5 hours. The polymerization reaction rate at this time was about 100%. Then, it was cooled to room temperature, sufficiently washed with water, dehydrated and dried to obtain a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed. Softening temperature of the obtained binder resin for toner, glass transition temperature,
Table 1 shows the weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industry Co., Ltd.) and polypropylene wax. (Sanyo Kasei Co., Ltd. "660P") 1 part by weight is kneaded for about 5 minutes at 150 ° C. using a twin-screw extruder, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 to 15 μm. Toner was obtained. Table 2 shows the evaluation results of the fixability, offset resistance, storage stability and moisture resistance of the obtained toner.

Comparative Example 1 41.5 parts by weight of styrene, n-butyl acrylate 8.5
To the monomer mixture consisting of parts by weight, t-as a polymerization initiator
Dissolve 0.02 parts by weight of butyl peroxybenzoate (“Per-Butyl Z” manufactured by NOF CORPORATION) and add 200 parts of deionized water.
The mixture is added to a mixture of 0.2 parts by weight of partially saponified polyvinyl alcohol ("Gosenol GH-23" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) and stirred. Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 2 hours.
The polymerization reaction rate at this time was about 70%. Furthermore, 40
41.5 parts by weight of styrene, 8.5 parts by weight of n-butyl acrylate, in a dispersion liquid of the high molecular weight polymer cooled to ℃,
6 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate (“Perbutyl Z” manufactured by NOF CORPORATION) were added, and the temperature was raised to 130 ° C. for 1.5 hours to suspend the low molecular weight polymer. Suspension polymerization was performed. The polymerization reaction rate at this time was about 100%. Then, it was cooled to room temperature, sufficiently washed with water, dehydrated and dried to obtain a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed. Table 1 shows the softening temperature, glass transition temperature, weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component of the obtained binder resin for toner.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industry Co., Ltd.) and polypropylene wax. (Sanyo Kasei Co., Ltd. "660P") 1 part by weight is kneaded for about 5 minutes at 150 ° C. using a twin-screw extruder, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 to 15 μm. Toner was obtained. Table 2 shows the evaluation results of the fixability, offset resistance, storage stability and moisture resistance of the obtained toner.

Comparative Example 2 0.2 part by weight of potassium peroxodisulfate as a polymerization initiator was dissolved in a monomer mixture consisting of 20 parts by weight of styrene and 5 parts by weight of n-butyl acrylate. This is added dropwise to an aqueous solution prepared by dissolving 0.5 parts by weight of sodium dodecylbenzenesulfonate in 150 parts by weight of deionized water and stirred. Then, after purging with nitrogen at 40 ° C. for 30 minutes,
The temperature was raised to 70 ° C. and the emulsion polymerization of the high molecular weight polymer was performed for 4.5 hours. The polymerization reaction rate at this time was about 70%. Then, 50 parts by weight of deionized water and partially saponified polyvinyl alcohol (“Gosenol GH-manufactured by Nippon Synthetic Chemical Industry Co., Ltd.” were added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C.
23 ") 0.2 part by weight was added. Furthermore, styrene 6
0 parts by weight, 15 parts by weight of n-butyl acrylate, 5 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate (“Perbutyl Z” manufactured by NOF CORPORATION) were added, and the temperature was raised to 130 ° C. Suspension polymerization of the low molecular weight polymer was carried out for 2 hours while warming. The polymerization reaction rate at this time was about 100%. Then, it was cooled to room temperature, sufficiently washed with water, dehydrated and dried to obtain a styrene-acrylic toner binder resin in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed. Table 1 shows the softening temperature, glass transition temperature, weight average molecular weight, content and molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component of the obtained binder resin for toner.

93 parts by weight of the obtained binder resin for toner, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei), 1 part by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Co., Ltd.) and polypropylene wax. (Sanyo Kasei Co., Ltd. "660P") 1 part by weight is kneaded for about 5 minutes at 150 ° C. using a twin-screw extruder, pulverized with a jet mill fine pulverizer, and classified to have a particle diameter of 5 to 15 μm. Toner was obtained. Table 2 shows the evaluation results of the fixability, offset resistance, storage stability and moisture resistance of the obtained toner.

[0045]

[Table 1]

[0046]

[Table 2]

[0047]

INDUSTRIAL APPLICABILITY According to the present invention, by incorporating a high molecular weight polymer component having a specific molecular weight distribution in gel permeation chromatography, the molecular weight distribution of the high molecular weight polymer component is wide, and the toner is fixed. It is possible to provide a binder resin for a toner which is excellent in resistance and offset resistance.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yoko Harada 2-1, 4-1, Ushikawa-dori, Toyohashi-shi, Aichi Sanryo Rayon Co., Ltd. Toyohashi Plant

Claims (4)

[Claims] 1. A styrene-acrylic resin comprising a high molecular weight polymer component and a low molecular weight polymer component, which has a main peak molecular weight of the high molecular weight polymer component in the molecular weight distribution by gel permeation chromatography. A binder resin for a toner, which has at least two peaks or shoulders on the high molecular weight side. 2. The chromatogram measured by gel permeation chromatography has main peaks of the low molecular weight polymer component and the high molecular weight polymer component, respectively, and the main peak of the low molecular weight polymer component is the molecular weight. It exists in the region of 1 × 10 ^{3 to} 3 × 10 ⁴ , and the main peak of the high molecular weight polymer component has a molecular weight of 5 × 10 ⁴ to 8 × 1.
The binder resin for toner according to claim 1, wherein the binder resin is present in the region of 0 ⁵ . 3. At least two peaks or shoulders present on the high molecular weight side of the main peak of the high molecular weight polymer component are present in the region of the molecular weight of 1 × 10 ^{5 to} 3 × 10 ^6. The binder resin for toner according to claim 2. 4. At least two peaks or shoulders present on the high molecular weight side of the main peak of the high molecular weight polymer component have a molecular weight range of 1 × 10 ⁵ to 1 × 10 ⁶ and a molecular weight of 1 × 10 ⁶ to 4. The binder resin for toner according to claim 3, wherein one or more of each is present in a region of 3 × 10 ⁶ .