JPH1010782A - Resin binder for toner and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner emitting slight odor, excellent in stability of a charged state and having well-balanced fixability and anti-offsetting property. SOLUTION: This resin binder for a toner contains high and low mol.wt. polymer components and has <=0.5wt.% volatile component content and <=1 mgKOH/g acid value. In the mol.wt. distribution of this resin binder by gel permeation chromatography, the mol.wt. (MH) of the peak top of the high mol.wt. polymer component is in the range of 1×10<5> -3×10<5> and the mol.wt. (ML) of the peak top of the low mol.wt. polymer component is in the range of 2×10<3> -3×10<4> . The ratio (MH/ML) of the mol.wt. of the peak top of the high mol.wt. polymer component to that of the low mol.wt. polymer component is 10-40 and the ratio (PH/PL) of the power (PH) of the peak top of the high mol.wt. polymer component to the power (PL) of the peak top of the low mol.wt. polymer component is 0.14-1.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner binder resin and a toner used for developing an electrostatic image or a magnetic latent image in electrophotography, electrostatic recording, electrostatic printing, and the like. More specifically, the present invention relates to a toner having a low odor, excellent charge stability, and a good balance between fixability and non-offset property, and a binder resin used for the toner.

[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.

In a copying machine, a printer, a facsimile, and the like used in an electrophotographic method, an electrostatic recording method, an electrostatic printing method, and the like, usually, a toner is heated using a heating roller heated to a temperature of about 100 to 230 ° C. Is fixed on paper.
In such a fixing process, fixing is often performed on a large number of sheets of paper or the like continuously, and a very small amount of toner that does not affect non-offset properties is accumulated on the heating roller. Then, the temperature of the heating roller increases due to continuous rotation and continuous supply of paper and the like, and the toner accumulated on the heating roller is heated, thereby evaporating residual monomers and residual solvent remaining in the toner. And produces odor. Such a problem of odor is caused by residual monomers and residual solvents contained in the binder resin for toner, and there is a demand for reduction of residual monomers and residual solvents of the binder resin.

[0005]

Conventionally, styrene-acrylic copolymers have been frequently used as binder resins for toners, and linear (non-crosslinked) resins and crosslinked resins have been used. I have. In a cross-linking type binder resin for a toner, attempts have been made to improve the fixability and the non-offset property as a toner by broadening the molecular weight distribution by cross-linking the resin. 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 / Attempts have been made to improve the fixing property and non-offset property of the toner by controlling Mn).

However, in the case of a crosslinked type binder resin for toner, it is difficult to obtain a toner having sufficient fixing characteristics because the balance between the fixing property and the non-offset property of the toner is poor only by crosslinking the resin. Met. In addition, since the dispersibility of the pigment or the like is poor, it is necessary to disperse the pigment by high shearing force. As a result, the crosslinked structure is cut and the non-offset property is reduced. On the other hand, the toner using a linear type toner binder resin has good dispersibility of pigments and the like,
For example, when the fixing property is improved, the melt viscosity of the binder resin for toner decreases, and the non-offset property of the toner decreases, and it is difficult to obtain a toner having a good balance between the two.

[0007] Regarding the reduction of the residual monomer and the residual solvent of the binder resin, see, for example, Japanese Patent Application Laid-Open No. 1-70.
As described in Japanese Patent Publication No. 765, a method has been proposed in which a resin obtained after polymerization is heated at a temperature equal to or higher than the glass transition temperature, and a predetermined amount of water is distilled off to reduce residual monomers. . However, in order to reduce the residual monomer in the resin by such a method, it is necessary to perform a very long-time treatment, and it is not possible to perform efficient production, or during the treatment, the resin particles are not separated from each other. There were problems such as aggregation and solidification. In order to prevent such agglomeration and solidification of the resin particles, a method of additionally adding a dispersant has been proposed, but the added dispersant remains in the resin as an impurity, and as a toner binder resin, Moisture resistance, transparency, etc. were reduced. Further, depending on the used starting monomers, polymerization initiator, and polymerization temperature, the content of the remaining monomers could not be sufficiently reduced. SUMMARY OF THE INVENTION An object of the present invention is to provide a binder resin for toner which has a low odor, is excellent in charge stability as toner, and has an excellent balance between fixing property and non-offset property.

[0008]

Means for Solving the Problems In view of such a situation, the present inventors have made intensive studies on a binder resin for a toner, and as a result, by reducing volatile components contained in the binder resin, the odor was reduced. Low toner content,
By controlling the molecular weight and molecular weight distribution of the high molecular weight polymer component constituting the binder resin, the toner binder resin is excellent in charge stability as toner and excellent in balance between fixing property and non-offset property. Have been found, and the present invention has been achieved.

That is, the binder resin for a toner of the present invention comprises a styrene-acrylic copolymer polymerized by a suspension polymerization method comprising a high molecular weight polymer component and a low molecular weight polymer component, and has a gel permeation. In the molecular weight distribution by chromatography, the molecular weight (M _H ) at the peak top of the high molecular weight polymer component is 1 × 10 ^{5 to} 3
× is in the range of 10 ^5, the molecular weight of the peak top of the low molecular weight polymer component (M _L) is in the range of 2 × 10 ³ to 3 × 10 ^4, the peak of the high molecular weight polymer component and a low molecular weight polymer component The top molecular weight ratio (M _H / M _L ) is 10 to 40,
The ratio (P _H / P _L ) of the peak top intensity (P _H ) of the high molecular weight polymer component to the peak top intensity (P _L ) of the low molecular weight polymer component is 0.14 to 1, and at 200 ° C. The content of the volatile component after drying for 2 hours is 0.5% by weight or less, and the acid value is 1 mgKOH / g or less. Further, the toner of the present invention contains the binder resin as described above.

[0010]

BEST MODE FOR CARRYING OUT THE INVENTION The binder resin for a toner of the present invention comprises a high molecular weight polymer component and a low molecular weight polymer component, and each polymer is composed of a styrene monomer and another copolymerizable vinyl resin. It is composed of a styrene-acrylic copolymer composed of monomers. In the present invention, the styrene monomer used for the polymerization of the high molecular weight polymer component and the low molecular weight polymer component includes styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-
Methyl styrene, p-ethyl styrene, 2,4-dimethyl styrene, pn-butyl styrene, p-tert-
Butylstyrene, pn-hexylstyrene, pn-
Octylstyrene, pn-nonylstyrene, pn-
Densyl styrene, pn-dodecyl styrene, p-phenyl styrene, 3,4-dicyclosyl styrene and the like can be mentioned, among which styrene is preferable. These styrene 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 And unsaturated monocarboxylic acids such as methacrylic acid, ethyl methacrylate, methyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate, and stearyl methacrylate And unsaturated dicarboxylic acid diesters such as esters, 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, monomethyl fumarate, fumarate Carboxylic acid-containing vinyl monomers such as unsaturated monocarboxylic acid monoesters such as monoethyl acrylate and monobutyl fumarate 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 is lowered, and the storage stability may be extremely lowered. Range. Glass transition temperature of binder resin for toner is 8
If the temperature exceeds 0 ° C., the softening temperature tends to increase, and the fixability of the toner tends to decrease.
It is in the range of 70 ° C. The binder resin for a toner of the present invention is composed of a high molecular weight polymer component and a low molecular weight polymer component, and the content ratio of the high molecular weight polymer component is in the range of 20 to 70% by weight. This is because the high molecular weight polymer component has 20
When the amount is less than 70% by weight, the non-offset property of the toner is poor. On the other hand, when the amount is more than 70% by weight, the fixing property as the toner is inferior.

In the present invention, by controlling the molecular weight distribution of a high molecular weight polymer component and a low molecular weight polymer component constituting a binder resin for a toner, a toner having a good balance between fixing property and non-offset property is provided. You can do it. That is, in the molecular weight distribution of the binder resin for toner by gel permeation chromatography, the molecular weight (M
_H) is in the region of ^{1 × 10 5 ~3 × 10 5} , the molecular weight of the peak top of the low molecular weight polymer component (M _L) is 2 × 10
^{In the range of 3 to} 3 × 10 ⁴ , the ratio of the molecular weight at the peak top of the high molecular weight polymer component and the low molecular weight polymer component (M _H /
M _L) is 10 to 40, the ratio of the intensity of the peak top of the high molecular weight polymer component (P _H) and the low molecular weight polymer component at a peak top intensity _{(P L) (P H /} P L) is 0 .14-
Must be 1.

This is because when the molecular weight (M _H ) at the peak top of the high molecular weight polymer component is less than 1 × 10 ⁵ ,
This is because the non-offset property as a toner decreases.
To be in the region of more than 3 × 10 ⁵ in the opposite with fixability of the toner is reduced, and because the dispersibility of the low-molecular weight polymer component is impaired, preferably 1.3 × 10 ⁵
２．５2.5 × 10 ⁵ , more preferably 1.
It is an area of 5 × 10 ^{5 to} 2 × 10 ⁵ . The molecular weight (M _H ) at the peak top of the low molecular weight polymer component is 2 × 10
^If the area is less than ³ , the mechanical strength of the binder resin is reduced, the toner is excessively pulverized in the charge generation step, and fogging is likely to occur on the image.
0 ⁴ to be in the range exceeding is because the fixability of the toner is reduced, preferably 5 × 10 ³ ~1.7 × 10
⁵ , more preferably 8 × 10 ^{3 to} 1.5
It is an area of × 10 ⁴ .

Further, when the ratio (M _H / M _L ) of the peak top molecular weight of the high molecular weight polymer component and the low molecular weight polymer component is less than 10, the balance between the fixing property and the non-offset property as a toner is not achieved. On the other hand, if it exceeds 40, the high molecular weight polymer component and the low molecular weight polymer component are not uniformly dispersed, causing a variation in properties among toner particles, and preferably in the range of 11 to 30. And more preferably in the range of 12 to 25. The ratio (P _H / P _L ) of the peak top intensity (P _H ) of the high molecular weight polymer component to the peak top intensity (P _L ) of the low molecular weight polymer component is 0.14.
If it is less than 1, the non-offset property of the toner is reduced, and if it is more than 1, the fixability as the toner is reduced, and preferably 0.17 to 0.95.
And more preferably in the range of 0.2 to 0.9.

In the present invention, from the viewpoint of the odor of the toner, the content of the volatile component of the binder resin is 0.5%.
It is necessary to be less than the weight%. The volatile component is a residual monomer or a residual solvent contained in the resin, and is a content of the volatile component remaining after the binder resin is dried at 200 ° C. for 2 hours. If such a volatile component is contained in an amount exceeding 0.5% by weight, a problem of odor as a toner occurs, and it is preferably in a range of 0.4% by weight or less, and more preferably in a range of 0.4% by weight or less. 3% by weight
The range is as follows. Further, from the viewpoint of charging stability of the toner, the acid value of the binder resin needs to be 1 mgKOH / g or less. This acid value is derived from the decomposition by-product of the polymerization initiator used at the time of polymerizing the resin, and the presence of such decomposition by-product impairs the charge stability of the toner. The acid value of the binder resin is 1 mgKOH /
When the amount exceeds g, the charging stability of the toner is reduced, and the range is preferably 0.7 mgKOH / g or less, more preferably 0.5 mgKOH / g or less.

The binder resin for a toner of the present invention can be produced by polymerizing a mixture of the above polymerizable monomers by a suspension polymerization method. The suspension polymerization method is
This is preferable because there is no problem of odor due to the residual solvent, the control of heat generation is easy, the amount of the dispersant used is small, and the moisture resistance is not impaired. In particular, the obtained toner binder resin is preferably composed of a uniformly mixed high molecular weight polymer component and low molecular weight polymer component, and suspension polymerization of the high molecular weight polymer component is performed. It is preferable to carry out polymerization by a polymerization method such as a two-stage suspension polymerization method in which suspension polymerization of a low molecular weight polymer component is carried out in the presence of suspended particles of a high molecular weight polymer component. Hereinafter, a method for producing the toner 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. Dispersant, polymerization initiator,
A molecular weight modifier or the like can be used.
It is preferable to carry out the reaction at 0 ° C. under a pressure of 0.5 to 7 kg / cm ² .

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 polymer component is polymerized by suspension polymerization in the presence of suspension particles of the high-molecular-weight polymer obtained by suspension polymerization. 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.

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.

Suspension polymerization is preferably carried out on one 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 the suspension polymerization is lowered, and the polymer tends to be solidified by aggregation of formed 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. .

In the present invention, after the suspension polymerization is substantially completed as described above, an alkali compound or an alkaline buffer solution is added to the polymerization system to raise the temperature higher than the glass transition temperature of the obtained polymer. An acid value of 1 m, which is excellent in charge stability as a toner by performing alkali treatment at a temperature.
A binder resin having a low acid value of gKOH / g or less can be obtained. Examples of the alkali compound used for the alkali treatment include hydroxides of alkali metals such as lithium, sodium, potassium, and rubidium, and among them, sodium hydroxide and potassium hydroxide are particularly preferable. These alkali compounds are used in an amount of 0.01 to 100 parts by weight of water.
It is preferable to use it in the range of 1 part by weight. This is because if the amount of the alkali compound used is less than 0.01, the effect of performing the alkali treatment is not sufficient, and if it exceeds 1 part by weight, it is necessary to use a large amount of the neutralizing agent in the wastewater treatment. is there.

The alkaline buffer solution is a commonly used solution having a buffering action, for example, Clark-Lubs' buffer, Sфrensen.
Buffer, Kolthoff buffer, Michael
is buffer, McIlvine buffer, Brit
ton-Robinson buffer, Carmody buffer, Gomori buffer, Bates-Bowe
r, Tris buffer, HEPES buffer, Good's buffer, Menzel's buffer, Waipole's buffer and the like. Among them, a Clark-Lubs buffer solution of potassium dihydrogen phosphate / sodium hydroxide buffer is particularly preferred. These buffer solutions are preferably used in such a range that the alkali metal compound contained in the buffer solution is in a range of 0.1 to 3 parts by weight with respect to the low molecular weight polymer monomer. This is because the alkali metal compound in the buffer solution is 0.1%.
If the amount is less than part by weight, a sufficient effect of the alkali treatment cannot be obtained.If the amount exceeds 3 parts by weight, the alkali metal compound becomes excessive, and a large amount of a neutralizing agent is required for wastewater treatment, and the resin is This is because hydrolysis tends to occur easily. When a potassium dihydrogen phosphate / sodium hydroxide buffer is used, 0.1 to 10 parts by weight of potassium dihydrogen phosphate and 0.1 to 3 parts by weight of sodium hydroxide are used based on the low molecular weight polymer monomer. Parts by weight, and the weight ratio of potassium dihydrogen phosphate to sodium hydroxide (potassium dihydrogen phosphate / sodium hydroxide) is preferably 1 to 5.

In the present invention, the alkali treatment is performed at a temperature higher than the glass transition temperature of the obtained polymer.
This is because when the alkali treatment temperature is lower than this, the treatment time required for the alkali treatment becomes longer, and especially when a large amount of the polymerization initiator is used, the alkali compound is used in a large amount, This is because it is necessary to perform the alkali treatment for a long time, and the acid value of the resin cannot be sufficiently reduced. If the alkali treatment temperature is too high, the hydrolysis of the polymer becomes remarkable, and the electrical properties and offset resistance of the toner are reduced. Therefore, the temperature should be 60 to 100 ° C. higher than the glass transition temperature of the polymer. Is preferred.

After the alkali treatment, the polymer is sufficiently washed and dehydrated to remove the alkali compound and dried.
Known methods can be used for these, for example, washing,
A centrifugal dehydrator, a super decanter, or the like is used for dehydration, and a box-type dryer, a vacuum dryer, or the like is used for drying.
In washing, an acid treatment may be performed to completely remove the alkali compound. The softening temperature of the binder resin for toner of the present invention obtained by such a production method is preferably in the range of 110 to 170 ° C. If the softening temperature is lower than 110 ° C., the non-offset property of the toner tends to decrease.
If the temperature exceeds 0 ° C., the fixability as a toner tends to decrease, and the temperature is more preferably in the range of 120 to 140 ° C.

In the present invention, the binder resin described above is preferably contained in the toner in the range of 88 to 97% by weight, more preferably 90 to 95% by weight.
Range. This is because the binder resin content is 88.
When the amount is less than 100% by weight, the non-offset property of the toner tends to decrease, and when the amount is more than 97% by weight, the charging stability of the toner tends to deteriorate. The toner of the present invention includes a binder, a colorant, a pigment, a charge control agent, an anti-offset agent, additives such as magnetic powder, for example, using a kneader such as a twin-screw extruder or a mixer, softening the binder resin. After kneading at a temperature higher by about 15 to 30 ° C. than the temperature, fine pulverization and classification are 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 colorant, pigment, charge control agent, anti-offset agent, and magnetic powder used in the toner may be those commonly used, such as carbon black, nigrosine dye, lamp black, Sudan black SM, and Navel. Yellow, Mineral First Yellow, Lisor Red,
Coloring agents or pigments such as permanent orange 4R, nigrosine, alkyl group-containing azine dyes, basic dyes,
Monoazo dye or its metal complex, salicylic acid or its metal complex, alkylsalicylic acid or its metal complex, charge control agent such as naphthoic acid or its metal complex, offset inhibitor such as polyethylene, polypropylene, ethylene-polypropylene copolymer, ferrite ,
Examples include magnetic powder such as magnetite.

[0028]

The present invention will be specifically described below with reference to examples. In the examples, the physical properties of the resin and the toner characteristics were measured by the following methods. Molecular weight by gel permeation chromatography
Distribution : A resin solution of 0.04% by weight using THF as a solvent is coated with a PTFE membrane (Mythodisc H-25 manufactured by Tosoh Corporation).
5), and filtered through three columns (TSKgel manufactured by Tosoh Corporation).
/ GMH _XL column) and gel permeation chromatography (HCL-8020 manufactured by Tosoh Corporation)
Measured at a temperature of 38 ° C. by F2000 / F700 /
F288 / F128 / F80 / F40 / F20 / F2 /
It was determined in terms of polystyrene by a calibration curve using A1000 (polystyrene manufactured by Tosoh Corporation) and a styrene monomer. The measurement temperature was 38 ° C., and the detector was RI.

Acid value : Measured by a titration method according to JIS K0070. Amount of volatile components : After the resin was pre-dried at 50 ° C. for 24 hours, it was dried in an oven heated to 200 ° C. for 2 hours, and the weight was determined before and after the drying. The odor of the resin when taken out of the oven was evaluated according to the following criteria. ：: Almost no odor is felt. X: Odor is felt.

Fixing temperature range : Using a fixing tester capable of freely changing the fixing temperature, a fixing speed of 130 mm /
The toner image is fixed at a pressure of 20 Kg for 2 seconds, and a cellophane tape is attached to the fixed toner image, and the initial density is set to 0.
As 6, the rate of change in image density when the cellophane tape was peeled was measured, and the temperature of the fixing roller at which the image density before and after peeling became 80% was defined as the lower limit temperature for fixing. In the same manner, the toner image was fixed, the state of contamination of the fixing roller by the toner was visually checked, and the minimum temperature at which contamination started was defined as the maximum fixing temperature.

Charge stability : Continuous copying is performed using a copying machine, and the number of copies is 2,000, 5,000, 100
At the time when the number of sheets reached 00, the toner in each copy machine was taken out, the charge amount was measured, and the stability of the charge amount was evaluated based on the following criteria. ：: Little change in charge amount. X: The change in charge amount is remarkable.

Example 1 To a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate, 2,2-bis (4,4-di-t-butylperoxycyclohexyl) was used as a polymerization initiator.
Propane (Perkadox 12 manufactured by Kayaku Akzo) 0.0
3 parts by weight are 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.). And stir. Then, the temperature was raised to 130 ° C. for 2 hours,
Suspension polymerization of high molecular weight polymer components was performed. At this time, the polymerization reaction rate was about 70%. Thereafter, a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate was added to a dispersion of the high molecular weight polymer component cooled to 40 ° C., and benzoyl peroxide was used as a polymerization initiator.
5 parts by weight and 1 part by weight of t-butyl peroxybenzoate (Nippon Oil & Fats Co., Ltd., Perbutyl Z) were added, and the temperature was raised to 130 ° C. to carry out suspension polymerization of the low molecular weight polymer component for 3 hours. Then, an alkaline aqueous solution in which 0.5 part by weight of sodium hydroxide was dissolved in 10 parts by weight of deionized water was added, and 30 parts by weight were added.
After performing an alkali treatment for 5 minutes, 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. I got Table 1 shows the measurement results of the molecular weight distribution, acid value, and volatile component amount of the obtained styrene-acrylic copolymer, and the odor evaluation results.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

Example 2 To a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate was added 2,2-bis (4,4-di-t-butylperoxycyclohexyl) as a polymerization initiator.
Propane (Perkadox 12 manufactured by Kayaku Akzo) 0.0
3 parts by weight are 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.). And stir. Then, the temperature was raised to 130 ° C. for 2 hours,
Suspension polymerization of high molecular weight polymer components was performed. At this time, the polymerization reaction rate was about 70%. Thereafter, a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate, and 5 parts by weight of benzoyl peroxide as a polymerization initiator were added to the dispersion of the high molecular weight polymer component cooled to 40 ° C. One part by weight of t-butyl peroxybenzoate (Perbutyl Z, manufactured by NOF CORPORATION) was added, and the temperature was raised to 130 ° C. to perform suspension polymerization of the low molecular weight polymer component for 3 hours.
Then, sodium hydroxide was added to 10 parts by weight of deionized water.
After adding an alkaline aqueous solution in which 5 parts by weight are dissolved and performing an alkaline treatment for 60 minutes, the mixture is cooled to room temperature, sufficiently washed, dehydrated and dried, and a high molecular weight polymer component and a low molecular weight polymer component are dried. Was uniformly mixed to obtain a styrene-acrylic copolymer. Table 1 shows the measurement results of the molecular weight distribution, acid value, and volatile component amount of the obtained styrene-acrylic copolymer, and the odor evaluation results.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.) and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

Example 3 To a monomer mixture consisting of 56 parts by weight of styrene and 14 parts by weight of n-butyl acrylate was added 2,2-bis (4,4-di-t-butylperoxycyclohexyl) as a polymerization initiator.
Propane (Perkadox 12 manufactured by Kayaku Akzo) 0.0
3 parts by weight are 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.). And stir. Then, the temperature was raised to 130 ° C. for 2 hours,
Suspension polymerization of high molecular weight polymer components was performed. At this time, the polymerization reaction rate was about 70%. Thereafter, a monomer mixture consisting of 24 parts by weight of styrene and 6 parts by weight of n-butyl acrylate, and 5 parts by weight of benzoyl peroxide as a polymerization initiator were added to the dispersion of the high molecular weight polymer component cooled to 40 ° C. One part by weight of t-butyl peroxybenzoate (Perbutyl Z, manufactured by NOF CORPORATION) was added, and the temperature was raised to 130 ° C. to perform suspension polymerization of the low molecular weight polymer component for 3 hours. Then, sodium hydroxide 0.5 was added to 10 parts by weight of deionized water.
After adding an alkaline aqueous solution in which parts by weight are dissolved and performing an alkaline treatment for 60 minutes, the mixture is cooled to room temperature, sufficiently washed, dehydrated, and dried, and a high molecular weight polymer component and a low molecular weight polymer component are dried. Were uniformly mixed to obtain a styrene-acrylic copolymer. Table 1 shows the measurement results of the molecular weight distribution, acid value, and volatile component amount of the obtained styrene-acrylic copolymer, and the odor evaluation results.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.) and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

Example 4 To a monomer mixture consisting of 24 parts by weight of styrene and 6 parts by weight of n-butyl acrylate was added 2,2-bis (4,4-di-t-butylperoxycyclohexyl) as a polymerization initiator.
Propane (Perkadox 12 manufactured by Kayaku Akzo) 0.0
3 parts by weight are 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.). And stir. Then, the temperature was raised to 130 ° C. for 2 hours,
Suspension polymerization of high molecular weight polymer components was performed. At this time, the polymerization reaction rate was about 70%. Thereafter, a monomer mixture consisting of 56 parts by weight of styrene and 24 parts by weight of n-butyl acrylate and 5 parts by weight of benzoyl peroxide as a polymerization initiator were added to the dispersion of the high molecular weight polymer component cooled to 40 ° C. One part by weight of t-butyl peroxybenzoate (Perbutyl Z, manufactured by NOF CORPORATION) was added, and the temperature was raised to 130 ° C. to perform suspension polymerization of the low molecular weight polymer component for 3 hours.
Then, sodium hydroxide was added to 10 parts by weight of deionized water.
After adding an alkaline aqueous solution in which 5 parts by weight are dissolved and performing an alkaline treatment for 60 minutes, the mixture is cooled to room temperature, sufficiently washed, dehydrated and dried, and a high molecular weight polymer component and a low molecular weight polymer component are dried. Was uniformly mixed to obtain a styrene-acrylic copolymer. Table 1 shows the measurement results of the molecular weight distribution, acid value, and volatile component amount of the obtained styrene-acrylic copolymer, and the odor evaluation results.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

Comparative Example 1 A monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate was added with 2,2-bis (4,4-di-t-butylperoxycyclohexyl) as a polymerization initiator.
Propane (Perkadox 12 manufactured by Kayaku Akzo) 0.0
3 parts by weight are 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.). And stir. Then, the temperature was raised to 130 ° C. for 2 hours,
Suspension polymerization of high molecular weight polymer components was performed. At this time, the polymerization reaction rate was about 70%. Thereafter, a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate, and 5 parts by weight of benzoyl peroxide as a polymerization initiator were added to the dispersion of the high molecular weight polymer component cooled to 40 ° C. One part by weight of t-butyl peroxybenzoate (Perbutyl Z, manufactured by NOF CORPORATION) was added, and the temperature was raised to 130 ° C. to perform suspension polymerization of the low molecular weight polymer component for 3 hours.
Next, the mixture was cooled to room temperature, sufficiently washed, dehydrated, and dried to obtain a styrene-acrylic copolymer in which a high molecular weight polymer component and a low molecular weight polymer component were uniformly mixed.
Molecular weight distribution of the obtained styrene-acrylic copolymer,
Table 1 shows the measurement results of the acid value and the amount of volatile components, and the evaluation results of the odor.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

Comparative Example 2 In a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate, 0.5 part by weight of benzoyl peroxide was dissolved as a polymerization initiator, and 200 parts by weight of deionized water was added. A mixture with 0.2 parts by weight of saponified polyvinyl alcohol ("Gosenol GH-23" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) is added and stirred. Next, the temperature was raised to 90 ° C., and suspension polymerization of the high molecular weight polymer component was performed for 2 hours.
At this time, the polymerization reaction rate was about 70%. Then 40
In a dispersion of the high molecular weight polymer component cooled to 0 ° C, a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate, 3.5 parts by weight of benzoyl peroxide as a polymerization initiator, and t -1 part by weight of butyl peroxybenzoate (Nippon Yushi Co., Ltd. perbutyl Z) was added,
The temperature was raised to 130 ° C., and suspension polymerization of the low molecular weight polymer component was performed for 3 hours. Next, an alkaline aqueous solution in which 0.5 part by weight of sodium hydroxide is dissolved in 10 parts by weight of deionized water is added, and alkali treatment is performed for 60 minutes, then cooled to room temperature, sufficiently washed, dehydrated, and dried. Was carried out to obtain a styrene-acrylic copolymer in which the high molecular weight polymer component and the low molecular weight polymer component were uniformly mixed. Table 1 shows the measurement results of the molecular weight distribution, acid value, and volatile component amount of the obtained styrene-acrylic copolymer, and the odor evaluation results.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

Comparative Example 3 To a monomer mixture consisting of 72 parts by weight of styrene and 8 parts by weight of n-butyl acrylate was added 2,2-bis (4,4-di-t-butylperoxycyclohexyl) as a polymerization initiator.
Propane (Perkadox 12 manufactured by Kayaku Akzo) 0.0
3 parts by weight are 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.). And stir. Then, the temperature was raised to 130 ° C. for 2 hours,
Suspension polymerization of high molecular weight polymer components was performed. At this time, the polymerization reaction rate was about 70%. Then, a monomer mixture consisting of 16 parts by weight of styrene and 4 parts by weight of n-butyl acrylate was added to the dispersion of the high molecular weight polymer component cooled to 40 ° C., and benzoyl peroxide 3.5 as a polymerization initiator.
1 part by weight of t-butyl peroxybenzoate (Nippon Oil & Fats Co., Ltd., Perbutyl Z) was added, the temperature was raised to 130 ° C., and suspension polymerization of the low molecular weight polymer component was performed for 3 hours. Then, an alkaline aqueous solution in which 0.5 part by weight of sodium hydroxide was dissolved in 10 parts by weight of deionized water was added, and 60 parts by weight were added.
After performing an alkali treatment for 5 minutes, 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. I got Table 1 shows the measurement results of the molecular weight distribution, acid value, and volatile component amount of the obtained styrene-acrylic copolymer, and the odor evaluation results.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

Comparative Example 4 To a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate was added 2,2-bis (4,4-di-t-butylperoxycyclohexyl) as a polymerization initiator.
Propane (Perkadox 12 manufactured by Kayaku Akzo) 0.0
3 parts by weight are 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.). And stir. Then, the temperature was raised to 130 ° C. for 2 hours,
Suspension polymerization of high molecular weight polymer components was performed. At this time, the polymerization reaction rate was about 70%. Thereafter, a monomer mixture consisting of 40 parts by weight of styrene and 10 parts by weight of n-butyl acrylate was added to a dispersion of the high molecular weight polymer component cooled to 40 ° C., and benzoyl peroxide was used as a polymerization initiator.
5 parts by weight were added, the temperature was raised to 130 ° C., and suspension polymerization of the low molecular weight polymer component was performed for 3 hours. Next, an alkaline aqueous solution in which 0.5 part by weight of sodium hydroxide is dissolved in 10 parts by weight of deionized water is added, and alkali treatment is performed for 60 minutes, then cooled to room temperature, sufficiently washed, dehydrated, and dried. Was carried out to obtain a styrene-acrylic copolymer in which the high molecular weight polymer component and the low molecular weight polymer component were uniformly mixed. Table 1 shows the measurement results of the molecular weight distribution, acid value, and volatile component amount of the obtained styrene-acrylic copolymer, and the odor evaluation results.

The obtained styrene-acrylic copolymer was used as a binder resin in 93 parts by weight, 5 parts by weight of carbon black (# 40 manufactured by Mitsubishi Kasei Co., Ltd.), and a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries, Ltd.). 1) 1 part by weight and polypropylene wax (660P manufactured by Sanyo Chemical Industries, Ltd.)
1 part by weight and mixed at 150 ° C. using a twin screw extruder.
Melted and kneaded for minutes. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having a particle diameter of 5 to 15 μm. Table 1 shows the fixing temperature range and the charging stability evaluation results of the obtained toner.

[0048]

[Table 1]

[0049]

According to the present invention, the balance between the fixing property and the non-offset property of the toner is controlled by controlling the molecular weight distribution of the high molecular weight polymer component and the low molecular weight polymer component constituting the binder resin. Provided is an excellent toner binder resin and toner which can suppress the odor of the toner by controlling the content of the components to a specific value or less and improve the charging stability of the toner by controlling the acid value to the specific value or less. You can do it.

Continued on the front page (72) Inventor Zouun Tajiri 4-1-1 Ushikawa-dori, Toyohashi-shi, Aichi Pref.

Claims (2)

[Claims] 1. A styrene-acrylic copolymer polymerized by a suspension polymerization method comprising a high molecular weight polymer component and a low molecular weight polymer component, and having a high molecular weight in a molecular weight distribution by gel permeation chromatography. The molecular weight (M _H ) at the peak top of the polymer component is 1 × 1
0 is in the ⁵ to 3 × 10 ⁵ range, the molecular weight of the peak top of the low molecular weight polymer component (M _L) is 2 × 10 ³ ~3 × 10
⁴ , and the ratio (M _H / M _L ) of the peak top molecular weight of the high molecular weight polymer component to the low molecular weight polymer component is 10
~ 40, peak top intensity of the high molecular weight polymer component (P
_H ) and the peak top intensity (P _L ) of the low molecular weight polymer component (P _H / P _L ) is 0.14 to 1;
A binder resin for toner, which has a volatile component content of 0.5% by weight or less and an acid value of 1 mg KOH / g or less after drying at 00 ° C. for 2 hours. 2. A toner comprising the binder resin according to claim 1.