JPH11316475A - Binder resin for toner and the toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a toner having superior balance in fixing property and non-offset property as the toner and superior excellent electrification stability and blocking resistance. SOLUTION: This binder resin contains a high mol.wt. polymer component, having equal to or lager than 2×5<5> weight average molecular weight and a low polymer component. The tetrahydrofuran-soluble component of the low molecular weight polymer component has a main peak in the range of <=3.5×10<4> , molecular weight in the molecular weight distribution measured by gel permeation chromatography and the low molecular weight polymer component contains 1 to 40 wt.% tetrahydrofuran-insoluble component. The glass transition temperative(TA) of the high molecular weight component and the glass transition tempetative(TB) of the low molecular weight polymer component satisfy the relation TA( deg.C)-5( deg.C)<=TB( deg.C)<=TA( deg.C)+5( deg.C).

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 binder resin for toner having an excellent balance between fixing property and non-offset property, and having excellent charge stability and blocking resistance, and a toner using the same.

[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 developing process, the toner and the binder resin for the toner are charged by a toner and a binder resin suitable for a copier or a printer without being affected by the surrounding environment such as temperature and humidity in order to attach the toner to the electric latent image. Must be maintained. Further, in the fixing step by the heat roller fixing method, the non-offset property that does not adhere to the heat roller and the fixability to paper must be good. Further, it is required to have a blocking resistance so that the toner does not block during storage in a copying machine.

Conventionally, binder resins for toners include:
Styrene-acrylic copolymers are frequently used, and linear (non-crosslinked) resins and crosslinked resins are used. As disclosed in JP-B-63-32180, a high-molecular-weight polymer component and a low-molecular-weight polymer component are mixed in a binder resin for a linear toner, and the glass transition temperature and molecular weight of both components are mixed. Attempts to improve the fixability and non-offset property of the toner by controlling the molecular weight distribution (Mw / Mn) of the entire resin as disclosed in Japanese Patent Publication No. 55-6895. Has been done.

In the case of a crosslinked type binder resin for a toner, attempts have been made to improve the fixability and non-offset property of the toner by broadening the molecular weight distribution by crosslinking the resin. As disclosed in Japanese Patent Publication No. 7-78646 and the like, a method for controlling the content of tetrahydrofuran-insoluble components and the molecular weight distribution of tetrahydrofuran-soluble components of a resin has been proposed. In addition, by using the crosslinked monomer only for the high molecular weight polymer component, the content of the tetrahydrofuran-insoluble component and the molecular weight distribution of the tetrahydrofuran soluble component of the resin are controlled, so that the high molecular weight polymer component having a crosslinked structure has a low content. A binder resin for a toner comprising a molecular weight polymer component and the like have also been proposed.

[0006]

However, a toner using a linear toner binder resin has good dispersibility of a colorant or the like. The melt viscosity was lowered and the non-offset property of the toner was reduced, and it was difficult to obtain a toner having a good balance between the two. On the other hand, in the case of a cross-linking type binder resin for a toner, it is difficult to obtain a toner having sufficient fixing characteristics because the balance between the fixing property and the non-offset property as a toner is poor by simply cross-linking the resin. . In addition, it is necessary to disperse by high shearing force due to poor dispersibility of the colorant and the like,
As a result, there is also a problem that the crosslinked structure is cut and the non-offset property is reduced.

Further, in the method of controlling the molecular weight distribution of a tetrahydrofuran-soluble component as disclosed in Japanese Patent Publication Nos. 7-13664 and 7-78646, etc.
There is a problem that it is difficult to sufficiently balance the blackout stability and the fixability as a toner due to the dispersibility of additives such as a colorant, a charge control agent and a wax, and a binder resin. Was. Further, in a binder resin for a toner comprising a high molecular weight polymer component having a crosslinked structure and a low molecular weight polymer component, although fixability as a toner is improved, additives such as a coloring agent, a charge control agent and a wax are used. There was a problem that charging stability was poor due to poor dispersibility. SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner binder resin and toner which are excellent in balance between fixing property and non-offset property as toner, and are excellent in charge stability and blocking resistance.

[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, introduced a cross-linked structure into a low molecular weight polymer component, thereby obtaining a low molecular weight polymer component. By adjusting the glass transition temperature of the high molecular weight polymer component to a specific range, a toner binder resin excellent in balance of fixing property and non-offset property as toner, charge stability and blocking resistance is obtained. The present inventors have found that they can be obtained, and have reached the present invention.

That is, the binder resin for a toner according to the present invention has a molecular weight of 3.0 as determined by gel permeation chromatography of a high molecular weight polymer component having a weight average molecular weight of 2 × 10 ⁵ or more and a tetrahydrofuran-soluble component. It has a main peak in a region of 5 × 10 ⁴ or less, contains a low molecular weight polymer component containing 1 to 40% by weight of a tetrahydrofuran insoluble matter, and has a glass transition temperature (TA) and a low molecular weight of the high molecular weight polymer component. The glass transition temperature (TB) of the polymer component satisfies the relationship of the following equation (1).

[0010]

## EQU2 ## TA (° C.)-5 (° C.) ≦ TB (° C.) ≦ TA (° C.) + 5 (° C.) (1) Further, the toner of the present invention comprises such a binder resin and a colorant. Is characterized by containing.

[0011]

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 preferably composed of a vinyl copolymer composed of a monomer, and particularly preferably composed of a styrene-acrylic copolymer.

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-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, p- n-octyl styrene, pn-nonyl styrene, pn-densyl styrene, pn-dodecyl styrene, p-phenyl styrene, 3,4-dicyclosyl styrene, etc., among which styrene is preferred . These styrene monomers can be used alone or in combination of two or more.

[0013] Other copolymerizable vinyl monomers include ethyl acrylate, methyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate. , Ethyl methacrylate, methyl methacrylate,
Unsaturated monocarboxylic acid esters such as n-butyl methacrylate, isobutyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, dimethyl maleate, diethyl maleate,
And unsaturated dicarboxylic acid diesters such as 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 Carboxylic acid-containing vinyl monomers such as unsaturated monocarboxylic acid monoesters such as monomethyl, monoethyl fumarate 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 to 80 ° C. This is because the storage stability of the toner can be improved by setting the glass transition temperature of the binder resin for the toner to 40 ° C. or higher, and the fixing property as the toner is improved by setting the glass transition temperature to 80 ° C. or lower. This is because you can do it. More preferably, it is in the range of 45 to 75 ° C, more preferably 50 to 70 ° C.
It is in the range of ° C.

The binder resin for a toner of the present invention comprises a tetrahydrofuran-insoluble component and a tetrahydrofuran-soluble component. In order to form a tetrahydrofuran-insoluble component in the binder resin for the toner, a method of imparting a cross-linked structure with a cross-linkable monomer or performing metal cross-linking may be mentioned. Is preferably introduced. By introducing such a crosslinked structure into at least the low molecular weight polymer component, the dispersibility of the colorant and the like is improved, the occurrence of fog and the like in an obtained image can be suppressed, and a toner having excellent image characteristics can be obtained. Can be. Such a crosslinked structure is preferably introduced only into the low-molecular-weight polymer component in order to sufficiently suppress the decrease in charging stability due to the dispersibility of the colorant and the like.

Examples of the crosslinkable monomer used to form a tetrahydrofuran-insoluble component include divinylbenzene, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, and 1,4. -Butanediol di (meth) acrylate,
1,5-pentadiol di (meth) acrylate, neopentyl di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate , Dipropylene glycol di (meth)
Examples include acrylate, polypropylene glycol di (meth) acrylate, pentaerythritol tri (meth) acrylate, trimethylolethanetri (meth) acrylate, and trimethylolpropane tri (meth) acrylate.

In the present invention, the low molecular weight polymer component comprises
Tetrahydrofuran insolubles are contained in the range of 1 to 40% by weight. 1% by weight of tetrahydrofuran insoluble content
As described above, the difference in viscosity during kneading with the high molecular weight polymer component is made as small as possible so that uniform mixing can be facilitated, whereby the charging stability as a toner can be improved. Further, by setting the content of the tetrahydrofuran-insoluble component to 40% by weight or less, the fixability as a toner can be improved. The content of the tetrahydrofuran-insoluble component in the low molecular weight polymer component is preferably in the range of 5 to 35% by weight, and more preferably in the range of 7 to 30% by weight.

Further, in the binder resin for a toner of the present invention, by controlling the molecular weight of a high molecular weight polymer component and a low molecular weight polymer component, a toner having a good balance between fixing property and non-offset property is provided. You can do it. That is, the weight average molecular weight of the high molecular weight polymer component is set to 2 × 10 ⁵ or more, and the molecular weight distribution of the tetrahydrofuran soluble component of the low molecular weight polymer component is determined by gel permeation chromatography to be 3.
A main peak is present in a region of 5 × 10 ⁴ or less.

The high molecular weight polymer component is a component that contributes to the non-offset property and strength of the toner. By setting the weight average molecular weight to 2 × 10 ⁵ or more, a sufficient non-offset area as the toner can be obtained. It is preferably obtained in a range of 3 × 10 ⁵ or more, and more preferably in a range of 3.5 × 10 ⁵ or more. The weight average molecular weight of the high molecular weight polymer component is preferably 1 × 10 ⁶ or less, from the viewpoints of fixability and crushability as a toner and dispersibility with the low molecular weight polymer component. It is preferably in the range of 7 × 10 ⁵ or less, preferably 5 ×
The range is 10 ⁵ or less.

The low molecular weight polymer component is a component that contributes to the fixability of the toner. The main peak in the molecular weight distribution of the tetrahydrofuran-soluble component determined by gel permeation chromatography is 3.5 × 10 5
^By being present in an area of ⁴ or less, good fixability as a toner can be obtained.
2 × 10 ⁴ or less, more preferably 3 × 1
0 ⁴ or less of the area. The main peak of the low molecular weight polymer component is preferably in a region having a molecular weight of 5 × 10 ³ or more, and more preferably in a region having a molecular weight of 1 × 10 ⁴ or more, from the viewpoints of blocking resistance and charge stability as a toner. It is.

Further, in the binder resin for a toner of the present invention, the glass transition temperature (T
It is important that the glass transition temperature (TB) of A) and the low molecular weight polymer component be in a range that satisfies the relationship of the following equation (1).

[0023]

## EQU3 ## TA (° C.)-5 (° C.) ≦ TB (° C.) ≦ TA (° C.) + 5 (° C.) (1) This is the glass transition temperature (TB) of the low molecular weight polymer component.
And the glass transition temperature (TA) of the high molecular weight polymer component within 5 ° C., the blocking resistance of the toner can be improved, and excellent storage stability can be maintained. This is because fixability and charging stability can be improved. The glass transition temperature (TA) of the high molecular weight polymer component and the glass transition temperature (TB) of the low molecular weight polymer component are preferably in a range that satisfies the following equation (2):

[0024]

## EQU00004 ## TA (.degree. C.)-3 (.degree. C.). Ltoreq.TB (.degree. C.). Ltoreq.TA (.degree. C.) + 3 (.degree. C.) (2) More preferably, the range satisfies the following expression (3). .

[0025]

(5) TA (° C.)-2 (° C.) ≦ TB (° C.) ≦ TA (° C.) + 2 (° C.) (3) In the present invention, the high molecular weight polymer component and the low molecular weight polymer component The content ratio is such that the high molecular weight polymer component is 15 to 70%.
It is preferable that the low molecular weight polymer component is 30 to 85% by weight in terms of% by weight. This is because by setting the content of the high molecular weight polymer component to 15% by weight or more, a sufficient non-offset region as a toner can be obtained.
This is because by setting the content to 0% by weight or less, the fixability and the charging stability of the toner can be improved. When the content of the low molecular weight polymer component is 30% by weight or more, the fixability and charge stability of the toner can be improved, and when the content is 85% by weight or less, sufficient toner can be obtained. This is because a non-offset area is obtained. More preferably, the high molecular weight polymer component is 20 to 65% by weight, and the low molecular weight polymer component is 35 to 8% by weight.
0% by weight, more preferably 25 to 25% by weight of the high molecular weight polymer component.
60% by weight, 40-75% by weight of low molecular weight polymer component
It is.

The binder resin for a toner of the present invention is prepared by subjecting a mixture of the above polymerizable monomers to a suspension polymerization method, a solution polymerization method,
It can be produced by a known polymerization method such as an emulsion polymerization method and a bulk polymerization method. Among them, those polymerized by the suspension polymerization method, without the problem of odor due to the residual solvent,
This is preferable because heat generation can be easily controlled, the amount of the dispersant used is small, and the moisture resistance of the toner is not impaired. The polymerization of the high molecular weight polymer component and the low molecular weight polymer component is carried out by polymerizing the high molecular weight polymer component and then polymerizing the low molecular weight polymer component in the presence of the high molecular weight polymer component, such as a two-stage polymerization method. The polymerization may be carried out by a method, or the high molecular weight polymer component and the low molecular weight polymer component may be individually polymerized and then melt-kneaded. In the present invention, from the viewpoint of imparting desired physical properties to each of the high molecular weight polymer component and the low molecular weight polymer component, a method in which both are individually polymerized and then melt-kneaded is preferable.

Hereinafter, the method for producing the binder resin for a toner of the present invention by the suspension polymerization method will be specifically described.
The suspension polymerization is not particularly limited and can be carried out according to a general suspension polymerization method, and together with the above-mentioned monomers, a dispersant generally used in suspension polymerization, Agents, molecular weight regulators and the like can be used.

The polymerization initiator used in the suspension polymerization is not particularly limited, and a generally used radically polymerizable peroxide or the like can be used. Particularly, as a polymerization initiator used for suspension polymerization of a high molecular weight polymer component, a compound having two or more peroxide groups in one molecule or a compound having a 10-hour half-life temperature of 9
It is preferable to use a radical polymerization initiator having one functional group in one molecule at 0 to 140 ° C.

Compounds having two or more peroxide groups in one molecule include 1,1-di-t-butylperoxy-3,3,5-trimethylcyclohexane and 1,3
-Bis (t-butylperoxyisopropyl) benzene, 2,5-dimethyl-2,5-di (t-butylperoxy) hexane, tris (t-peroxy) triazine, 1,1-di-t-butylper Oxycyclohexane, 2,2-di-t-butylperoxybutane, di-t
-Butylperoxyhexahydroterephthalate, di-t-butylperoxytrimethyladipate, 2,2
-Bis (4,4-di-t-butylperoxycyclohexyl) propanate, 2,2-t-butylperoxyoctane and the like. The 10-hour half-life temperature is 9
Examples of the radical polymerization initiator having one functional group in one molecule at 0 to 140 ° C. include t-butylperoxylaurate, t-butylperoxy 3,5,5-trimethylhexanoate, and cyclohexanone peroxide. T-butylperoxyisopropyl carbonate, t-butylperoxyacetate, t-butylperoxybenzoate, dicumyl peroxide, t-butylcumyl peroxide, diisopropylbenzene hydroperoxide,
Di-t-butyl peroxide, p-methane hydroperoxide, 2- (carbamoylazo) isobutyronitrile, 2,2-azobis (2,4,4-trimethylpentane), 2-phenylazo-2,4- Organic peroxides such as dimethyl-4-methoxyvaleronitrile and azo compounds are exemplified.

These polymerization initiators can be used alone or in combination of two or more. Among them, a compound having two or more peroxide groups in one molecule is preferable, and more preferably three or more peroxide groups are used in order to polymerize a high molecular weight high molecular weight polymer component in a relatively short time. And more preferably a compound having four or more peroxide groups in one molecule, such as 2,2-bis (4,4-di-t-butylperoxycyclohexyl) propanate. The amount of the polymerization initiator to be used is 0.01 to 100 parts by weight of all monomers.
It is preferably used in the range of 10 to 10 parts by weight, more preferably in the range of 0.1 to 5 parts by weight.

Examples of the polymerization initiator used for suspension polymerization of the low molecular weight polymer component include di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, acetyl peroxide, and the like. Isobutyryl peroxide, octonyl peroxide, decanoyl peroxide, lauroyl peroxide, 3,5,5-
Trimethylhexanoyl peroxide, benzoyl peroxide, m-toluoyl peroxide, t-butyl peroxyacetate, t-butyl peroxyisobutyrate, t-butyl peroxypiparate, t-butyl peroxy neodecanoate , Cumyl peroxy neodecanoate, t-butyl peroxy 2-ethylhexanoate, t-butyl peroxy 3,5,5-trimethyl hexanoate, t-butyl paoxy ylate, t-butyl peroxy benzoate, Examples thereof include t-butyl peroxyisopropyl carbonate, azobisisobutylnitrile, and 2,2-azobis- (2,4-dimethylvaleronitrile). From the point that polymerization is completed in time,
Octonyl peroxide, decanoyl peroxide,
Lauroyl peroxide, benzoyl peroxide, m
-Trioil peroxide is preferred. These polymerization initiators can be used alone or in combination of two or more, and are preferably used in the range of 0.1 to 10 parts by weight, more preferably 0.1 to 10 parts by weight, per 100 parts by weight of the monomer. It is in the range of 5 to 7 parts by weight.

[0032] The suspension polymerization is preferably carried out with respect to the monomer.
10 to 10 times, more preferably about 2 to 4 times with water, adding a dispersant, a polymerization initiator, a dispersing aid or a molecular weight modifier as needed, and raising the temperature to a predetermined polymerization temperature, This is done by continuing the heating.

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, and the like. 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 used in an amount of 0.0
It is preferable to use it in the range of 1 to 5 parts by weight. If the amount of the dispersant is less than 0.01 part by weight, the stability of suspension polymerization is reduced, and the polymer tends to be solidified by aggregation of the produced particles, and conversely, the amount exceeds 5 parts by weight. This is because the toner tends to have a lower environmental dependency, particularly the moisture resistance, and the content is more preferably in the range of 0.05 to 2 parts by weight. If necessary, a dispersing aid such as sodium chloride, potassium chloride, sodium sulfate and potassium sulfate can be used together with these dispersants. further,
In order to adjust the molecular weight, a molecular weight adjuster 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, the binder resin described above is preferably contained in the toner in the range of 70 to 97% by weight, more preferably 80 to 95% by weight.
Range. This results in a binder resin content of 70
When the content is not less than 97% by weight, the non-offset property of the toner can be improved, and when the content is not more than 97% by weight, the charging stability of the toner can be improved. The toner of the present invention comprises, together with a binder resin, additives such as a wax, a colorant, a pigment, a charge control agent, an anti-offset agent, and a magnetic powder, for example, by using a kneading machine such as a twin-screw extruder or a mixer. Is kneaded at a temperature about 15 to 30 ° C. higher than the softening temperature of the mixture, and then finely pulverized and classified to form a toner. The obtained toner particles have an average particle size of about 5 to 20 μm, preferably 8 to 15 μm.
μm, 3% by weight of fine particles with a particle size of 5 μm or less
It is preferably less than.

The wax, colorant, pigment, charge control agent, anti-offset agent, and magnetic powder used in the toner may be those commonly used, for example, waxes such as low molecular weight polyolefin waxes such as polypropylene wax. Used in the range of 0.5 to 5% by weight based on the toner), carbon black, nigrosine dye, lamp black, Sudan black SM, navel yellow, mineral fast yellow, lithol red, permanent orange 4R, etc. Or charge control agents such as pigments, nigrosine, alkyl-containing azine dyes, basic dyes, monoazo dyes or their metal complexes, salicylic acid or its metal complexes, alkylsalicylic acids or their metal complexes, naphthoic acids or their metal complexes, polyethylene ,polypropylene, Styrene - polypropylene copolymer anti-offset agent such as ferrite, and a magnetic powder such as magnetite.

[0036]

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. Tetrahydrofuran (THF) insolubles : Celite 545
(Katayama Chemical Co., Ltd.) was shaken with a sieve having an opening of 0.045 mm, and the celite under the sieve was filled in a glass filter (1G-3), washed with acetone, and then vacuum dried at 80 ° C. for 3 hours or more. The weight (W1) at the time of the weighing is weighed. After adding 50 ml of THF to 0.5 g of resin (W2) to this glass filter and heating at 60 ° C. for 3 hours,
The THF solution is suction filtered. Next, the THF-insoluble matter remaining on the glass filter is completely washed away with acetone, and vacuum drying is performed at 80 ° C. for 3 hours or more. Then, the weight (W3) of the glass filter is weighed, and the following formula (1) is obtained. Was calculated.

[0037]

## EQU1 ## THF-insoluble matter (%) = {(W3-W1) / W2} × 100 (1) Molecular weight by gel permeation chromatography
Distribution : 0.4% by weight resin solution using THF as a solvent,
Gel permeation chromatography (manufactured by Tosoh Corporation) composed of three columns (manufactured by Tosoh Corporation, TSKgel / GMH _XL column) filtered through a 0.5 μm PTFE membrane (manufactured by Tosoh Corporation, Misholidisc H-25-5) HCL
−8020) at a temperature of 38 ° C.
/ F700 / F288 / F128 / F80 / F40 / F
It was determined in terms of polystyrene by a calibration curve using 20 / F2 / A1000 (standard polystyrene manufactured by Tosoh Corporation) and a styrene monomer. The measurement temperature was 38 ° C,
The detector was performed by RI.

Glass transition temperature : A 10 mg sample was placed in an aluminum pan, covered with an aluminum cover, and the sample melted at 100 ° C. for 10 minutes was rapidly cooled.
DSC measurement was performed at a heating rate of 0 ° C./min, and the shoulder value was adopted.

Fixing temperature range : Using a fixing tester with a variable roller temperature, a fixing speed of 130 mm / sec and a pressure of 20 kg.
As a sand eraser (JIS 51
Rubbing was performed 9 times in 2), and the image density before and after the rubbing was measured with a Macbeth densitometer. The results were indicated by the minimum temperature at which the density was reduced by less than 20% and the minimum temperature at which the toner transferred to the roller.

The charge stability of the obtained toner was measured for 120 minutes by blow-off, and the change in the charge amount was evaluated according to the following criteria. ：: The charge stability is extremely excellent. Δ: Excellent in charging stability. X: Poor charge stability.

Storage stability : The storage stability is about 5%.
The state of blocking after being left in a hot-air dryer kept at 0 ° C. for 50 hours was visually evaluated according to the following criteria. ：: No blocking occurs. Δ: Blacking is slightly observed. X: Blocking is remarkable.

High molecular weight polymer component (A-1) A monomer mixture comprising 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate was added with 2,2-
Bis (4,4-di-t-butylperoxycyclohexyl) propanate (Perkadox 1 manufactured by Kayaku Akzo)
2)) Dissolve 0.4 parts by weight, and add 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 into the mixture and stir. Next, the temperature was raised to 90 ° C., and suspension polymerization was performed for 10 hours. Thereafter, the mixture was cooled to room temperature, sufficiently washed and dehydrated, and dried at 50 ° C. for 20 hours to obtain a high molecular weight polymer component (A-1). The glass transition temperature and the weight average molecular weight of the obtained high molecular weight polymer component (A-1) are shown in Table 1.

High molecular weight polymer component (A-2) A high molecular weight polymer component (A-1) was used except that di-t-butylperoxy-hexahydroterephthalate was used in an amount of 1.0 part by weight as a polymerization initiator. In the same manner, a high molecular weight polymer component (A-2) was obtained. Table 1 shows the glass transition temperature and the weight average molecular weight of the obtained high molecular weight polymer component (A-2).

High molecular weight polymer component (A-3) Except that 0.3 parts by weight of benzoyl peroxide is used as a polymerization initiator, a high molecular weight polymer is prepared in the same manner as in the high molecular weight polymer component (A-1). A combined component (A-3) was obtained. Table 1 shows the glass transition temperature and the weight average molecular weight of the obtained high molecular weight polymer component (A-3).

High molecular weight polymer component (A-4) A high molecular weight polymer component (A-1) was used except that a monomer mixture comprising 90 parts by weight of styrene and 10 parts by weight of n-butyl acrylate was used. In the same manner, a high molecular weight polymer component (A-4) was obtained. The obtained high molecular weight polymer component (A
Table 1 shows the glass transition temperature and weight average molecular weight of -4).

High molecular weight polymer component (A-5) Except for using a monomer mixture consisting of 70 parts by weight of styrene and 30 parts by weight of n-butyl acrylate, In a similar manner, a high molecular weight polymer component (A-5) was obtained. The obtained high molecular weight polymer component (A
Table 1 shows the glass transition temperature and weight average molecular weight of -5).

[0047]

[Table 1]

Low molecular weight polymer component (B-1) A monomer mixture comprising 80 parts by weight of styrene, 20 parts by weight of n-butyl acrylate and 1.1 parts by weight of 1,3-butylene glycol dimethacrylate is Dissolve 2.5 parts by weight of benzoyl peroxide as a polymerization initiator, 200 parts by weight of deionized water and partially saponified polyvinyl alcohol ("Gosenol GH-23" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) 0.2 Add to the mixture with parts by weight and stir. Then 130
C., and the suspension polymerization was carried out for 3 hours. Thereafter, the mixture was cooled to room temperature, sufficiently washed and dehydrated, and dried at 50 ° C. for 20 hours to obtain a low molecular weight polymer component (B-1). Table 2 shows the glass transition temperature, the THF insoluble content, and the molecular weight peak of the THF soluble component of the obtained low molecular weight polymer component (B-1) by GPC.

Low molecular weight polymer component (B-2) A monomer mixture comprising 80 parts by weight of styrene, 20 parts by weight of n-butyl acrylate and 0.6 parts by weight of 1,3-butylene glycol dimethacrylate; Except that 1.5 parts by weight of t-butylperoxy-2-ethylhexanoate was used, in the same manner as in the low-molecular-weight polymer component (B-1),
A low molecular weight polymer component (B-2) was obtained. Table 2 shows the glass transition temperature, the THF insoluble content, and the THF soluble component of the obtained low molecular weight polymer component (B-2) by GPC.
It was shown to.

Low molecular weight polymer component (B-3) A monomer mixture comprising 80 parts by weight of styrene, 20 parts by weight of n-butyl acrylate and 0.4 parts by weight of 1,3-butylene glycol dimethacrylate is T- as a polymerization initiator
Dissolve 0.8 parts by weight of butyl peroxy-2-ethylhexanoate, and add 200 parts by weight of deionized water and partially saponified polyvinyl alcohol ("Goseno-" manufactured by Nippon Synthetic Chemical Industry Co., Ltd.).
GH-23 ") in a mixture with 0.2 parts by weight. Next, the temperature was raised to 90 ° C., and suspension polymerization was performed for 3 hours. Thereafter, the mixture was cooled to room temperature, sufficiently washed and dehydrated, and dried at 50 ° C. for 20 hours to obtain a low molecular weight polymer component (B-3). Glass transition temperature, THF-insoluble content, THF of the obtained low molecular weight polymer component (B-3)
Table 2 shows the molecular weight peak of the soluble component by GPC.

Low molecular weight polymer component (B-4) A monomer mixture comprising 80 parts by weight of styrene and 20 parts by weight of n-butyl acrylate, and t-butyl peroxy-2
-A low molecular weight polymer component (B-4) was obtained in the same manner as in the low molecular weight polymer component (B-1) except that 2.0 parts by weight of ethylhexanoate was used. Table 2 shows the glass transition temperature, the amount of THF insoluble matter, and the molecular weight peak of the THF soluble matter by GPC of the obtained low molecular weight polymer component (B-4).

Low molecular weight polymer component (B-5) 80 parts by weight of styrene, 20 parts by weight of n-butyl acrylate and 0.84 of 1,3-butylene glycol dimethacrylate
Parts by weight of a monomer mixture, and t as a polymerization initiator.
-Butyl peroxy-2-ethylhexanoate 1.2
Except that parts by weight were used, the low molecular weight polymer component (B-
A low molecular weight polymer component (B-5) was obtained in the same manner as in 3). Table 2 shows the glass transition temperature, the amount of THF insoluble matter, and the molecular weight peak of the THF soluble matter by GPC of the obtained low molecular weight polymer component (B-5).

[0053]

[Table 2]

Examples 1-7, Comparative Examples 1-6 93 parts by weight of a mixture of a high molecular weight polymer component and a low molecular weight polymer component in the proportions shown in Table 3, carbon black (# 40 manufactured by Mitsubishi Chemical Corporation) 5 parts by weight, 1 part by weight of a charge control agent (Bontron S-34 manufactured by Orient Kako Co., Ltd.) and 1 part by weight of polypropylene wax (660P manufactured by Sanyo Chemical Co., Ltd.) were put into a batch-type mixer and kneaded. The resulting kneaded material was roughly pulverized and then finely pulverized using a jet mill to a particle size of 15 μm or less. Further, fine particles having a particle size of 5 μm or less were removed using a zigzag classifier to obtain toner particles. The fixing area, charging stability and storage stability of the obtained toner were evaluated, and the results are shown in Table 3.

[0055]

[Table 3]

[0056]

According to the present invention, a crosslinked structure is introduced into at least the low molecular weight polymer component of the binder resin,
By controlling the molecular weight and glass transition temperature of the high molecular weight polymer component and the low molecular weight polymer component, a toner having an excellent balance of fixing property and non-offset property as a toner, and having excellent charge stability and blocking resistance. Binder resin and toner.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Junya Nakamura 4-1-1 Ushikawa-dori, Toyohashi-shi, Aichi Prefecture Inside the Toyohashi Works of Mitsubishi Rayon Co., Ltd. (72) Inventor, etc. 4-1-1 Ushikawa-dori, Toyohashi-shi, Aichi Prefecture Address No. 2 Mitsubishi Rayon Co., Ltd. Toyohashi Office

Claims (3)

[Claims] 1. A high-molecular-weight polymer component having a weight-average molecular weight of 2 × 10 ⁵ or more and a tetrahydrofuran-soluble component having a molecular weight of 3.5 × 10 ⁴ or less in a molecular weight distribution by gel permeation chromatography. A low-molecular-weight polymer component having a peak and containing 1 to 40% by weight of a tetrahydrofuran-insoluble component, and a glass transition temperature (TA) of the high-molecular-weight polymer component and a glass transition temperature (TB) of the low-molecular-weight polymer component. ) Satisfies the following expression (1): ## EQU1 ## TA (° C.)-5 (° C.) ≦ TB (° C.) ≦ TA (° C.) + 5 (° C.) (1) 2. A high molecular weight polymer component comprising 15 to 70% by weight.
2. The binder resin for a toner according to claim 1, further comprising 30 to 85% by weight of a low molecular weight polymer component. 3. A toner comprising the binder resin according to claim 1 and a colorant.