JPH08184994A - Resin binder for toner - Google Patents

Abstract

PURPOSE: To obtain a resin binder excellent in fixability, blocking resistance, anti-offsetting property and strength as a toner. CONSTITUTION: This resin binder is obtd. by suspension polymn. using a multifunctional polymn. initiator such as a compd. having three or more t-butyl peroxide groups in one molecule, contains a low mol.wt. polymer component and 40-75wt.% high mol.wt. polymer component having a wt. average mol.wt. of >=350,000, has 60-80 deg.C glass transition temp. and does not practically contain fine powder.

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 in electrophotography, electrostatic printing, etc., and more specifically, a toner excellent in fixing property, blocking resistance, non-offset property and strength. The present invention relates to a binder resin for toner, which is particularly suitable for a non-magnetic one-component toner that requires high toner strength.

[0002]

2. Description of the Related Art In a method for obtaining a permanent visible image from an electrostatic charge image, an electrostatic charge image formed on a photoconductive photosensitive member or an electrostatic recording material is developed with a toner charged in advance by friction. Is fixed. In the case of a magnetic latent image,
The latent image on the magnetic drum is developed with toner containing a magnetic material and then fixed. For fixing, the toner image obtained by development is directly fused on the photoconductive photoreceptor or the electrostatic recording body, or the toner image is transferred onto paper or film and then fused onto the transfer sheet. Done by.
Toner image fusion is performed by contact with solvent vapor, pressurization and heating, and there are two types of heating method: non-contact heating method using an electric oven and pressure heating method using a pressure roller. Recently, the latter is mainly used.

Toners used in the dry developing system include one-component toners and two-component toners. A two-component toner is prepared by first melt-kneading a binder resin, a colorant, a charge control agent and other necessary additives to sufficiently disperse them, then roughly pulverizing them and then finely pulverizing them to classify them into a predetermined particle size range. Manufactured. The one-component toner is manufactured in the same manner by adding magnetic iron powder in addition to each component of the above two-component toner. Since the binder resin is the main component in the toner formulation, it controls most of the performance required for the toner. For this reason, the toner resin is required to have good dispersibility of the colorant in the melt-kneading step and good pulverizability in the pulverizing step in the toner production.
A variety of performances such as non-offset property, blocking resistance and good electrical properties are required. Epoxy resins, polyester resins, polystyrene resins, methacrylic resins, etc. are known as the resins used in the production of toners, but styrene and (meth) are mainly used for pressure-bonding heat fixing systems.
Acrylic ester copolymers have been used.

[0004]

However, as the performance of copiers and printers has become higher, the performance required for binder resins has also changed depending on the type of copier. For example, a portable type small copying machine is often used for general household use, has a relatively low printing rate, and the toner is mixed for a long time during charging in the developing process in the copying machine. In addition, there is a problem in that the toner is excessively pulverized and the particle size is reduced, and accordingly, the charge amount is changed and the density of the copy is changed.

Further, in such household copying machines and plain paper facsimiles, a non-magnetic one-component developing system has been used for the purpose of machine downsizing and maintenance-free, and toner is used for the developing roll. A method of charging by strongly rubbing is used. In such a developing system, by rubbing the toner against the developing roll in the charging step, the toner is easily crushed and the charge amount is apt to change very easily, and the toner is melted by the frictional heat generated during rubbing. There are problems such as wearing and sticking to the roll.

When a styrenic resin is used as a binder resin in such a developing system, the toner is extremely easily crushed due to insufficient strength of the binder resin, causing fog in the copy or density. It causes a problem such as a decrease in. For the purpose of solving these problems, methods such as super-polymerizing the binder resin and raising the glass transition temperature are also performed,
The viscosity of the binder resin was drastically increased and the fixability was lowered. In addition, since the styrene resin polymerized by the bulk polymerization method or the solution polymerization method is used as a binder resin after being reduced in particle size by pulverization, the resin particles have corners, and the resin particles are It also has a problem of high flow resistance. Further, there is a problem in handling such as scattering of fine powder generated when the binder resin is pulverized. Therefore, it is an object of the present invention to provide a binder resin for toner which can provide a toner excellent in fixing property, blocking resistance, non-offset property and strength.

[0007]

In view of such circumstances, the inventors of the present invention have made earnest studies on the binder resin for toner, and as a result, by using a specific polymerization initiator, the fixing property as a toner, The present invention has been accomplished by finding that a binder resin for toner having excellent blocking resistance and non-offset property and high resin strength can be obtained. That is, the binder resin for a toner of the present invention is a binder resin for a toner, which is polymerized by a suspension polymerization method using a polyfunctional polymerization initiator, and comprises a high molecular weight polymer component and a low molecular weight polymer component, 40-75
It is characterized by containing wt% of a high molecular weight polymer component having a weight average molecular weight of 350,000 or more, a glass transition temperature of 60 to 80 ° C. and substantially no fine powder.

The binder resin for a toner of the present invention comprises a high molecular weight polymer component and a low molecular weight polymer component which are uniformly mixed, and each polymer component is a styrene monomer or another copolymerizable vinyl resin. It is made of a polymer or copolymer made of a monomer or the like, and particularly preferably made of a styrene-acrylic copolymer. In the present invention, the styrenic monomer used for polymerizing the high molecular weight polymer component and the low molecular weight polymer component may be styrene, o
-Methyl styrene, m-methyl styrene, p-methyl styrene, α-methyl styrene, p-ethyl styrene,
2,4-dimethylstyrene, pn-butylstyrene,
p-tert-butylstyrene, p-n-hexylstyrene, p-n-octylstyrene, p-n-nonylstyrene, p-n-densylstyrene, p-n-dodecylstyrene, p-phenylstyrene, 3, 4-dicrosyl styrene etc. are mentioned, Especially, styrene is preferable. These styrene-based monomers can be used alone or in combination of two or more.

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. A carboxylic acid-containing vinyl monomer such as an unsaturated monocarboxylic acid monoester such as monomethyl, monoethyl fumarate or monobutyl fumarate may also be used in combination. The copolymerization ratio of these monomers is not particularly limited, but it is preferable to select in the range where the glass transition temperature (Tg) of the obtained binder resin for toner is 60 to 80 ° C.

It is important that the binder resin for toner of the present invention has a glass transition temperature in the range of 60 to 80 ° C. from the viewpoint of the balance of fixing property as a toner, blocking resistance and non-offset property. This is because when the glass transition temperature is lower than 60 ° C., the frictional heat generated when rubbing the toner against the developing roll tends to cause the toners to fuse with each other or adhere to the roll. This is because if the temperature exceeds 80 ° C., the fixability as a toner tends to be poor, and the range is preferably 65 to 75 ° C. The polymerized high molecular weight polymer component constituting the binder resin for toner of the present invention needs to have a weight average molecular weight (Mw) of 350,000 or more. This is because when the weight average molecular weight of the high molecular weight polymer component is less than 350,000, the non-offset property as a toner tends to decrease, and preferably 400,000 or more, more preferably 50.
The range is over 10,000. Further, if the weight average molecular weight of the high molecular weight polymer component is too large, the fixability as a toner tends to decrease, and it is preferably in the range of 1.5 million or less.

The low molecular weight polymer component preferably has a weight average molecular weight of 2,000 to 50,000. This is because when the weight average molecular weight is less than 2000, the mechanical strength of the binder resin for toner decreases, the toner tends to be in an excessively pulverized state at the time of charging, and fog tends to occur in the image. This is because if it exceeds the range, the fixability as a toner tends to decrease. In the present invention, the ratio of the high molecular weight polymer component to the low molecular weight polymer component needs to be in the range of 40 to 75% by weight of the high molecular weight polymer component. This is because if the high molecular weight polymer component is less than 40% by weight, the non-offset property as a toner and the resin strength tend to be poor, and conversely if it exceeds 75% by weight, the fixability as a toner tends to be poor. This is because it is in the range of 50 to 75% by weight.

The binder resin for a toner of the present invention is polymerized by a suspension polymerization method using a polyfunctional polymerization initiator, and by using the polyfunctional polymerization initiator, a high molecular weight polymer is obtained. The molecular weight of the component can be easily increased and the strength of the resin can be increased. On the other hand, when a monofunctional polymerization initiator is used, it is difficult to increase the molecular weight of the high molecular weight polymer component, and even if the molecular weight is increased, a resin having sufficient resin strength cannot be obtained. . As the method for producing the binder resin for a toner of the present invention, a high molecular weight polymer component is polymerized by a suspension polymerization method using a polyfunctional polymerization initiator, and a low molecular weight polymer component is present in the presence of the high molecular weight polymer component. Is preferably polymerized by a suspension polymerization method from the viewpoint of obtaining a binder resin for toner in which a high molecular weight polymer component and a low molecular weight polymer component are uniformly mixed.

The suspension polymerization of the high molecular weight polymer component is carried out at a high temperature of 95 ° C. or higher by using a polyfunctional polymerization initiator as a polymerization initiator together with the above-mentioned monomer for high molecular weight polymer. Preferably. The polyfunctional polymerization initiator used for suspension polymerization of the high molecular weight polymer component is a compound having 3 or more t-butylperoxide groups in one molecule, such as 2,2-bis ( 4,4-di-t
-Butylpa-oxycyclohexyl) propane and the like. These polymerization initiators may be used in a very small amount as compared with the amount of the polymerization initiator used in the conventional suspension polymerization, and the range of 0.001 to 0.5% by weight in the monomer for high molecular weight polymer. It is preferable to use at 0.002, more preferably 0.002
Is in the range of 0.1% by weight. This is because when the amount of the polymerization initiator used is less than 0.001% by weight, the polymerization rate becomes slow and it tends to take a long time to obtain a polymer having a target molecular weight. This is because if it exceeds the range, it tends to be difficult to sufficiently increase the molecular weight.

In the suspension polymerization of the high molecular weight polymer component, a polyfunctional polymerization initiator is used as a polymerization initiator, and the high molecular weight polymer component is 95 ° C. or higher, preferably 95 to 150 ° C., more preferably By polymerizing by suspension polymerization at a high temperature of 110 to 150 ° C., a polymerization initiator is efficiently consumed, and a high molecular weight polymer component having a weight average molecular weight of 350,000 or more and a high molecular weight is used for about 1 to 3 hours. It can be obtained in a short time. In the present invention, in the presence of the suspension polymerized high molecular weight polymer component,
The low molecular weight polymer component is polymerized by the suspension polymerization method. 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 40 to 7
At about 5%, 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. In addition,
When the monomer for low molecular weight polymer is added, it is preferable to add such an amount that the content of the low molecular weight polymer component in the obtained binder resin for toner is in the range of 25 to 60% 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 polymerization of the high molecular weight polymer component or the low molecular weight polymer component by the suspension polymerization method is preferably 1 to 10 times, more preferably 2 to 4 times as much as the amount of water. At the same time, a dispersant, a polymerization initiator, and if necessary, a dispersion aid or a chain transfer agent are added, the temperature is raised to a predetermined polymerization temperature, and heating is continued until a predetermined polymerization rate is achieved. Be seen.

Dispersants 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, Examples thereof include calcium carbonate, magnesium carbonate, and calcium phosphate. Among them, polyvinyl alcohol is preferable, and particularly preferable is partially saponified polyvinyl alcohol in which an acetic acid group and a hydroxyl group are present in a block manner. These dispersants are 0.0 to 100 parts by weight of water.
It is preferably used in the range of 1 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. If necessary, a dispersing aid such as sodium chloride, potassium chloride, sodium sulfate or 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, or α-methylstyrene dimer may be used, if necessary. .

[0019]

EXAMPLES The present invention will be specifically described below with reference to examples. In the examples, the glass transition temperature (Tg) is D after heating the sample to 100 ° C. and melt quenching.
It was determined by the SC method (heating rate 10 ° C./min). The weight average molecular weight is a value measured by gel permeation chromatography, was measured by using HCL-8020 manufactured by Tosoh Corporation as a solvent, and was calculated by polystyrene conversion.

The fixing property is such that after a test image is formed by a non-magnetic one-component printer, a fixing tester capable of freely changing the fixing temperature is used and the fixing speed is 130 mm / sec.
A cellophane tape was applied to the fixed toner image at a pressure of 20 kg, the cellophane tape was peeled off, and the change in image density before and after peeling was visually evaluated according to the following criteria. ◯: Almost no change in image density. X: Image density change is relatively large.

The non-offset property is obtained by using a fixing tester capable of freely changing the fixing temperature after forming a test image with a non-magnetic one-component printer, and fixing speed of 130 m.
The degree of contamination by the toner of the fixing roller was visually determined at m / sec and a pressure of 20 kg, and the following criteria were used to evaluate the extent of the temperature range in which there was no contamination on the fixing roller. ◯: A very wide temperature range without roller contamination. X: A narrow temperature range without roller contamination.

The pulverizability is obtained by finely pulverizing the coarsely pulverized toner with a jet mill fine pulverizer, measuring the average particle diameter of the obtained finely pulverized toner, and determining the toner strength (resin strength) from the pulverized state as follows. It was evaluated according to the standard. ◯: A resin having sufficient resin strength as a binder resin for non-magnetic one-component toner. X: A resin having insufficient resin strength as a binder resin for non-magnetic one-component toner.

Example 1 58.45 parts by weight of styrene, n-butyl acrylate 1
2,2-bis (4,4) as a polymerization initiator was added to a monomer mixture consisting of 0.5 parts by weight and 1.05 parts by weight of methacrylic acid.
-Di-t-butylperoxycyclohexyl) propane ("Parkadox 12" manufactured by Kayaku Akzo Co., Ltd.) 0.042
Part by weight was dissolved and added to a mixture of 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.). Stir. 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, 26.55 parts by weight of styrene was added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C.
N-Butyl acrylate 3 parts by weight, methacrylic acid 0.45
Parts by weight, 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. for 1.5 hours for a low molecular weight. Suspension polymerization of the coalescence was carried out. 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 monomer composition, glass transition temperature, weight average molecular weight and content of the high 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), polypropylene wax (660P manufactured by Sanyo Kasei)
1 part by weight and 1 part by weight of a charge control agent (“Bontron S-34” manufactured by Orient Chemical Industry Co., Ltd.) were kneaded for about 30 minutes at 150 ° C. using a twin-screw extruder and pulverized using a jet mill fine pulverizer. Then, a toner is obtained. Table 1 shows the evaluation results of the fixability, non-offset property and toner strength of the obtained toner.
It was shown to.

Example 2 51.8 parts by weight of styrene, n-butyl methacrylate 1
To the monomer mixture consisting of 8.2 parts by weight, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propane as a polymerization initiator ("Par-Cadox 12" manufactured by Kayaku Akzo Co., Ltd.) Dissolve 0.042 parts by weight of deionized water 2
00 parts by weight and 0.2 parts by weight of partially saponified polyvinyl alcohol (“Gosenol GH-23” manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) are added to a mixture and stirred. Then 130 ° C
The suspension was heated for 2 hours to carry out suspension polymerization of the high molecular weight polymer. The polymerization reaction rate at this time was about 70%. further,
22.2 parts by weight of styrene, 7.8 parts by weight of n-butyl methacrylate, 5 parts by weight of benzoylperoxide and t-butylperoxybenzoate (NOF Corporation) were added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C. 1 part by weight of "Per-Butyl Z" manufactured by the company) was 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 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 monomer composition, glass transition temperature, weight average molecular weight and content of the high 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), polypropylene wax (660P manufactured by Sanyo Kasei)
1 part by weight and 1 part by weight of a charge control agent (“Bontron S-34” manufactured by Orient Chemical Industry Co., Ltd.) were kneaded for about 30 minutes at 150 ° C. using a twin-screw extruder and pulverized using a jet mill fine pulverizer. Then, a toner is obtained. Table 1 shows the evaluation results of the fixability, non-offset property and toner strength of the obtained toner.
It was shown to.

Example 3 A monomer mixture consisting of 85 parts by weight of styrene, 13.5 parts by weight of n-butyl acrylate and 1.5 parts by weight of methacrylic acid was added to 2,2-bis (4,4) as a polymerization initiator. -Di-t-
Butyl peroxycyclohexyl) propane (Kayaku Akzo "Perkadox 12") 0.06 parts by weight is dissolved, deionized water 200 parts by weight and partially saponified polyvinyl alcohol (Nippon Gosei Kagaku Co., Ltd. -Cenol GH-2
3 ") Add to a mixture with 0.2 parts by weight and stir.
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, 5 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate ("Perbutyl Z" manufactured by NOF Corporation) were added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C. Increase the temperature to 130 ℃
Suspension polymerization of the low molecular weight polymer was carried out for a period of time. 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 monomer composition, glass transition temperature, weight average molecular weight and content of the high 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), polypropylene wax (660P manufactured by Sanyo Kasei)
1 part by weight and 1 part by weight of a charge control agent (“Bontron S-34” manufactured by Orient Chemical Industry Co., Ltd.) were kneaded at 150 ° C. for about 30 minutes using a twin-screw extruder and pulverized using a jet mill fine pulverizer. Then, a toner is obtained. Table 1 shows the evaluation results of the fixability, non-offset property and toner strength of the obtained toner.
It was shown to.

Comparative Example 1 2,2-bis (4,4-di-t-butylperoxycyclohexyl) as a polymerization initiator was added to a monomer mixture consisting of 56 parts by weight of styrene and 14 parts by weight of n-butyl acrylate. Propane (Kayaku Akzo Co., Ltd. "Parkadox 1
2 ") 0.042 parts 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 2 hours. The polymerization reaction rate at this time was about 70%. Furthermore, 40 ℃
In the dispersion of the high molecular weight polymer cooled to
4 parts by weight, 6 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 1.5 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 monomer composition, glass transition temperature, weight average molecular weight and content of the high 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), polypropylene wax (660P manufactured by Sanyo Kasei)
1 part by weight and 1 part by weight of a charge control agent (“Bontron S-34” manufactured by Orient Chemical Industry Co., Ltd.) were kneaded for about 30 minutes at 150 ° C. using a twin-screw extruder and pulverized using a jet mill fine pulverizer. Then, a toner is obtained. Table 1 shows the evaluation results of the fixability, non-offset property and toner strength of the obtained toner.
It was shown to.

Comparative Example 2 A monomer mixture consisting of 85 parts by weight of styrene, 13.5 parts by weight of n-butyl acrylate and 1.5 parts by weight of methacrylic acid was added to 2,2-bis (4,4) as a polymerization initiator. -Di-t-
Butyl peroxycyclohexyl) propane (Kayaku Akzo "Perkadox 12") 0.06 parts by weight is dissolved, deionized water 200 parts by weight and partially saponified polyvinyl alcohol (Nippon Gosei Kagaku Co., Ltd. -Cenol GH-2
3 ") Add to a mixture with 0.2 parts by weight and stir.
Next, the temperature was raised to 130 ° C. and suspension polymerization of the high molecular weight polymer was performed for 4 hours. The polymerization reaction rate at this time was about 80%. Further, 5 parts by weight of benzoylperoxide and 1 part by weight of t-butylperoxybenzoate ("Perbutyl Z" manufactured by NOF Corporation) were added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C. Increase the temperature to 130 ℃
Suspension polymerization of the low molecular weight polymer was carried out for a period of time. 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 monomer composition, glass transition temperature, weight average molecular weight and content of the high 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), polypropylene wax (660P manufactured by Sanyo Kasei)
1 part by weight and 1 part by weight of a charge control agent (“Bontron S-34” manufactured by Orient Chemical Industry Co., Ltd.) were kneaded for about 30 minutes at 150 ° C. using a twin-screw extruder and pulverized using a jet mill fine pulverizer. Then, a toner is obtained. Table 1 shows the evaluation results of the fixability, non-offset property and toner strength of the obtained toner.
It was shown to.

Comparative Example 3 42.5 parts by weight of styrene, n-butyl acrylate 7.5
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 ") 0.03 parts by weight are dissolved, and 200 parts by weight of deionized water and 0.2 parts 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 2 hours. The polymerization reaction rate at this time was about 70%. Furthermore, styrene 45 was added to the dispersion liquid of the high molecular weight polymer cooled to 40 ° C.
Parts by weight, 5 parts by weight of n-butyl acrylate, 5 parts by weight of benzoylperoxide and t-butylperoxybenzoic acid.
1 part by weight of "Perbutyl Z" (manufactured by Nippon Oil & Fats Co., Ltd.) was added, and the temperature was raised to 130 ° C to carry out suspension polymerization of the low molecular weight polymer 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. Table 1 shows the monomer composition, glass transition temperature, weight average molecular weight and content of the high 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), polypropylene wax (660P manufactured by Sanyo Kasei)
1 part by weight and 1 part by weight of a charge control agent (“Bontron S-34” manufactured by Orient Chemical Industry Co., Ltd.) were kneaded for about 30 minutes at 150 ° C. using a twin-screw extruder and pulverized using a jet mill fine pulverizer. Then, a toner is obtained. Table 1 shows the evaluation results of the fixability, non-offset property and toner strength of the obtained toner.
It was shown to.

Comparative Example 4 51.8 parts by weight of styrene, n-butyl methacrylate 1
To a monomer mixture consisting of 8.2 parts by weight, 0.042 parts by weight of t-butylperoxybenzoate (“Perbutyl Z” manufactured by NOF CORPORATION) as a polymerization initiator was dissolved, and 200 parts by weight of deionized water was dissolved. Parts and partially saponified polyvinyl alcohol ("Gosenol GH-23" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.)
Add to a mixture with 2 parts by weight and stir. Then 1
Suspension polymerization of the high molecular weight polymer was carried out for 4 hours by raising the temperature to 30 ° C. The polymerization reaction rate at this time was about 70%. Furthermore, in the dispersion liquid of the high molecular weight polymer cooled to 40 ° C., 22.2 parts by weight of styrene, 7.8 parts by weight of n-butyl methacrylate, 5 parts by weight of benzoylperoxide and t-
1 part by weight of butyl peroxybenzoate ("Perbutyl Z" manufactured by NOF CORPORATION) was added, and the temperature was raised to 130 ° C.
Suspension polymerization of the low molecular weight polymer was carried out for 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. Table 1 shows the monomer composition, glass transition temperature, weight average molecular weight and content of the high 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), polypropylene wax (660P manufactured by Sanyo Kasei)
1 part by weight and 1 part by weight of a charge control agent (“Bontron S-34” manufactured by Orient Chemical Industry Co., Ltd.) were kneaded at 150 ° C. for about 30 minutes using a twin-screw extruder and pulverized using a jet mill fine pulverizer. Then, a toner is obtained. Table 1 shows the evaluation results of the fixability, non-offset property and toner strength of the obtained toner.
It was shown to.

[0037]

[Table 1]

The symbols of the monomer composition in the table are as follows. St: Styrene n-BA: N-butyl acrylate BMA: N-Butyl methacrylate MAA: Methacrylic acid

[0039]

INDUSTRIAL APPLICABILITY The present invention provides a binder resin for a toner, which is excellent in fixability, blocking resistance, non-offset property and strength as a toner and is particularly suitable for a non-magnetic one-component toner which requires high toner strength. It is possible.

 ─────────────────────────────────────────────────── ─── 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 (1)

[Claims] 1. A binder resin for toner comprising a high molecular weight polymer component and a low molecular weight polymer component, which is polymerized by a suspension polymerization method using a polyfunctional polymerization initiator.
A binder resin for a toner, which contains 0 to 75% by weight of a high molecular weight polymer component having a weight average molecular weight of 350,000 or more, a glass transition temperature of 60 to 80 ° C., and contains substantially no fine powder.