JPH09258481A - Resin for toner and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a toner having well-balanced fixability and anti-offsetting property. SOLUTION: This resin for a toner is a styrene copolymer consisting of a high mol.wt. polymer component and a low mol.wt. polymer component and contains 0.1-50wt.% THF-insoluble part. The wt. average mol.wt. of the THF- soluble part of the high mol.wt. polymer component is 200,000-600,000 and that of the low mol.wt. polymer component is 6,000-30,000. Elution start time (Ts), top part elution time (Tt) and elution end time (Te) in the gel permeation chromatography of the high mol.wt. polymer component satisfy the relation of (Ts-Tt)>=(Tt-Te).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner 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 resin and a toner having excellent balance between non-offset property and fixability, and particularly excellent fixability at low temperature.

[0002]

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

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

Conventionally, binder resins for toners include:
Styrene-acrylic resins are frequently used, and linear type (non-crosslinked type) resins and crosslinked type resins are used. In the cross-linking type binder resin for toner,
As described in JP-B-51-23354, it has been attempted to broaden the molecular weight distribution by crosslinking a resin to improve the fixability and non-offset property as a toner. Further, in the linear type binder resin for toner, as described in JP-B-55-6895 and JP-B-63-32183, a high molecular weight polymer component and a low molecular weight polymer component are mixed. hand,
Attempts have been made to improve the fixing property and non-offset property of the toner by controlling the glass transition temperature and the molecular weight of both components and the molecular weight distribution (Mw / Mn) of the entire resin.

[0005]

However, in the case of a crosslinked type binder resin for a toner, simply cross-linking the resin is inferior in the balance between the fixing property and the non-offset property as a toner and has a sufficient fixing property. It was difficult to obtain a toner. Further, since the dispersibility of the pigment and the like is poor, it is necessary to disperse the pigment by a high shearing force, and as a result, there is a problem that the crosslinked structure is cut and the non-offset property is lowered. On the other hand, a toner using a binder resin for a linear toner has good dispersibility of pigments, etc., but, for example, when the fixability is improved, the melt viscosity of the binder resin for a toner is lowered and the toner is not offset. Toner with a good balance between the two
Was hard to get.

On the other hand, copiers and printers have a tendency to save energy by lowering the power consumption thereof, and as the functionality of the copiers and printers increases, the power consumption for fixing tends to decrease further. There is a demand for low-temperature fixability of the toner used. Therefore, an object of the present invention is to provide a toner resin and a toner which are excellent in the balance between the fixability and the non-offset property, and particularly excellent in the fixability at low temperatures.

[0007]

In view of such circumstances, the inventors of the present invention have made diligent studies on the binder resin contained in the toner, and as a result, have determined the molecular weight and melting characteristics of the high molecular weight polymer component constituting the binder resin. It was found that a toner having an excellent balance between fixability and non-offset property and fixability at low temperature can be obtained by controlling the toner, and has reached the present invention. That is, the toner resin of the present invention is a styrene-based copolymer comprising a high molecular weight polymer component and a low molecular weight polymer component, and containing 0.1 to 50% by weight of THF insoluble matter. The weight average molecular weight of the THF soluble component of the combined component is 200,000 to 6
The weight average molecular weight of the THF-soluble component of the low molecular weight polymer component is 6,000 to 30,000, and the elution start time (Ts) of the high molecular weight polymer component in gel permeation chromatography is The top part elution time (Tt) and the elution end time (Te) satisfy the relationship of the following expression (1). The toner of the present invention is characterized by containing such a styrene copolymer as a binder resin.

[0008]

(2) Ts-Tt ≧ Tt-Te (1)

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The styrenic copolymer of the present invention is
Consists of high molecular weight polymer component and low molecular weight polymer component,
Any of the polymers is a non-crosslinked styrene-based copolymer composed of a styrene-based monomer and another copolymerizable vinyl-based monomer, and a styrene-acrylic-based copolymer is particularly preferable. In the present invention, examples of the styrene-based monomer used for polymerizing the high molecular weight polymer component and the low molecular weight polymer component include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α- Methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, Examples thereof include pn-densyl styrene, pn-dodecyl styrene, p-phenyl styrene, and 3,4-dicyclosyl styrene. Among them, 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. , Unsaturated carboxylic acids such as methacrylic acid, ethyl methacrylic acid, methyl methacrylic acid, n-butyl methacrylic acid, isobutyl methacrylic acid, propyl methacrylic acid, 2-ethylhexyl methacrylic acid and stearyl methacrylic acid Examples thereof include esters, unsaturated dicarboxylic acid diesters such as dimethyl maleate, diethyl maleate, butyl maleate, dimethyl fumarate, diethyl fumarate, and dibutyl fumarate.

Further, unsaturated monocarboxylic acids such as acrylic acid, methacrylic acid and cinnamic acid, unsaturated dicarboxylic acids such as maleic acid, fumaric acid and itaconic acid, monomethyl maleate, monoethyl maleate, monobutyl maleate and fumaric acid. A carboxylic acid-containing vinyl monomer such as an unsaturated monocarboxylic acid monoester such as monomethyl, monoethyl fumarate or monobutyl fumarate may also be used in combination. The copolymerization ratio of these monomers is not particularly limited, but it is preferably selected so that the glass transition temperature of the obtained styrene-based copolymer is in the range of 50 to 80 ° C. This is because when the glass transition temperature is lower than 50 ° C., the blocking occurrence temperature of the toner may be lowered, and storage stability may be extremely lowered. This is because the property tends to decrease, and it is preferably in the range of 55 to 70 ° C.

In the present invention, the crosslinking monomer used for forming the THF (tetrahydrofuran) insoluble component in the styrene copolymer is a vinyl monomer having two or more functional groups, that is, a reactive dimer in one molecule. Double bond 2
Reactive vinyl monomers having more than one are used, for example, aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, ethylene glycol di (meth) acrylate, 1,3-butylene glycol di (meth) acrylate, 1,4- Butylene glycol di (meth) acrylate, 1,5-butylene glycol di (meth) acrylate, neopentyl glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di ( (Meth) acrylate, polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth) acrylate, polypropylene glycol di (meth) acrylate, bisphenol A derivative-based di (meth) Bifunctional vinyl monomers such as acrylate, pentaerythritol tri (meth) acrylate, trimethylolpropane Enta tri (meth) acrylate,
Examples thereof include trifunctional vinyl-based monomers such as trimethylolpropane tri (meth) acrylate, and these can be used alone or in combination of two or more kinds.
Of these, divinylbenzene and 1,3-butylene glycol dimethacrylate are preferable. These bifunctional or higher vinyl-based monomers have a content of 0.3 to 5 with respect to all monomer components.
It is preferably used in the range of wt%, more preferably 0.4 to 4.5 wt%. This is 0.3
If it is less than 5% by weight, the cross-linking structure of the styrene-based copolymer is insufficient and the non-offset property of the toner tends to be poor. This is because there is a tendency to be damaged.

In the present invention, the styrene copolymer contains a high molecular weight polymer component and a low molecular weight polymer component,
The ratio is preferably such that the content of the high molecular weight polymer component in the THF-soluble component is in the range of 5 to 50% by weight. This is because when the content of the high molecular weight polymer component is less than 5% by weight, the non-offset property as a toner tends to be poor, and when it exceeds 50% by weight, the fixability as a toner tends to be poor. This is because, and more preferably 1
It is in the range of 0 to 40% by weight. Further, the ratio of the high molecular weight polymer component and the low molecular weight polymer component is such that the softening temperature of the styrene-based copolymer is 100 to 1 as measured by a flow tester.
It is preferable to adjust the temperature in the range of 80 ° C. This is because when the softening temperature of the styrene-based copolymer is less than 100 ° C., the non-offset property as a toner tends to be poor, and conversely, when it exceeds 180 ° C., the fixing property as a toner tends to decrease. Because it is in. More preferably, the styrene-based copolymer has a softening temperature of 110 to 160.
It is in the range of ° C.

Further, the high molecular weight polymer component constituting the styrene-based copolymer needs to have a weight average molecular weight of the THF-soluble component in the range of 200,000 to 600,000. It has a weight average molecular weight of 200,000.
If it is less than 60%, the non-offset property as a toner is deteriorated, and if it exceeds 600,000, the fixing property as a toner is deteriorated.
It is in the range of 50,000 to 500,000. As the low molecular weight polymer component, the weight average molecular weight of the THF-soluble component needs to be in the range of 6,000 to 30,000. This is because when the weight average molecular weight of the low molecular weight polymer component is less than 6,000, the mechanical strength of the resin is lowered, the toner is likely to be in an excessively pulverized state when electrification occurs, and fog tends to occur in the image. Is. On the contrary, if the weight average molecular weight exceeds 30,000, the fixability as a toner is lowered. Preferably 7,000
Is in the range of 20,000.

Further, in the present invention, a toner having a good balance of fixing property and non-offset property can be provided by controlling the melting property together with the molecular weight of the high molecular weight polymer component constituting the styrene copolymer. It is a thing. That is, the elution start time (T of gel permeation chromatography) of the high molecular weight polymer component (T
When the s), the elution time (Tt) of the top portion, and the elution end time (Te) satisfy the relationship of the following expression (1), it is possible to provide a binder resin having excellent fixability as a toner. The melting characteristic of the high molecular weight polymer component is the above (1).
If the range is not satisfied, the responsiveness of the styrene-based copolymer as a binder resin for toner to heat is delayed, and the fixability as a toner is lowered.

[0016]

## EQU00003 ## Ts-Tt.gtoreq.Tt-Te (1) In the present invention, the elution start time (Ts), the top elution time (Tt) and the elution end time (Te) are styrene-based copolymer In the measurement of the gel permeation chromatography of the coalescence, it represents the time required from the start of the measurement, and the elution start time (Ts) is the time until the elution of the high molecular weight polymer component starts,
t) is the time until the maximum peak of the molecular weight distribution in the gel permeation chromatography of the high molecular weight polymer component is eluted, and the elution end time (Te) is the time until the elution of the high molecular weight polymer component is completed. Represents

The above-mentioned styrenic copolymer can be prepared by a known polymerization method such as a suspension polymerization method, a solution polymerization method, an emulsion polymerization method or a bulk polymerization method of the above-mentioned polymerizable monomer. There is no problem of odor due to solvent,
The suspension polymerization method is preferable from the viewpoints that the heat generation is easily controlled, the amount of the dispersant used is small, and the moisture resistance is not impaired. In particular, the obtained binder resin is preferably composed of a high-molecular weight polymer component and a low-molecular weight polymer component that are uniformly mixed, and suspension polymerization of the high-molecular weight polymer component is performed, and then the high-molecular weight polymer component is polymerized. Polymerization is preferably carried out by a polymerization method such as a two-step suspension polymerization method in which suspension polymerization of a low molecular weight polymer component is carried out in the presence of suspended particles of the polymer component.

The method for producing a styrene copolymer by the two-step suspension polymerization method will be specifically described below. 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 generally used in suspension polymerization together with the above monomers. Dispersants, polymerization initiators, molecular weight regulators, etc. can be used, and the temperature is 95 to 150 ° C. and the pressure is 0.5 to 7 k.
It is preferably carried out under the condition of g / cm ² .

As the polymerization initiator used for suspension polymerization of the high molecular weight polymer component, a compound having three or more t-butylperoxide groups in one molecule or a 10-hour half-life temperature of 90 to 140 ° C. It is possible to use a radical polymerization initiator having one functional group in one molecule. For example, 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 a very small amount as compared with the amount of the polymerization initiator used in the conventional suspension polymerization, and 0.001 to 0.5 parts by weight based on 100 parts by weight of all the monomers. It is preferably used in the range of parts, and more preferably 0.002 to 0.05 parts by weight.

Next, the low molecular weight polymer component is polymerized by suspension polymerization in the presence of the suspension particles of the suspension polymerized high molecular weight polymer. 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,
The monomer is preferably used in the range of 0.1 to 10 parts by weight, more preferably 0.5 to 100 parts by weight.
The range is 10 parts by weight.

The suspension polymerization is preferably 1 per monomer.
With about 10 times, more preferably about 2 to 4 times water, a dispersant, a polymerization initiator, and optionally a dispersion aid or a chain transfer agent are added, and the temperature is raised to a predetermined polymerization temperature. The heating is continued until the polymerization rate reaches a predetermined level. 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 or potassium sulfate can be used together with these dispersants. further,
In order to adjust the molecular weight, a chain transfer agent such as n-octyl mercaptan, n-dodecyl mercaptan, t-dodecyl mercaptan, 2-ethylhexyl thioglycolate, or α-methylstyrene dimer may be used, if necessary. .

The styrene-based copolymer obtained by such a production method has a THF insoluble content of 0.1 to 50% by weight.
Is preferably within the range. This is because when the THF insoluble content is less than 0.1% by weight, the cross-linking structure of the styrene-based copolymer is insufficient and the toner non-offset property tends to be poor.
This is because if it exceeds 50% by weight, the softening temperature of the styrene-based copolymer becomes high and the fixing property of the toner tends to be impaired. The toner of the present invention contains the above styrene-based copolymer as a binder resin, and the styrene-based copolymer may be used alone as the binder resin. It is also possible to use the polymer as a main component in combination with other resins such as other styrene / acrylic resins, styrene / butadiene resins, polyester resins, etc. to form a binder resin. Further, the toner of the present invention contains 60% by weight or more of the binder resin as described above, and is a coloring agent such as an inorganic pigment such as carbon black or iron black, a chromatic dye or an organic pigment, a negative charging property or a positive charging property. A charge control agent or the like having an electrostatic property may be blended as necessary, and the resulting blend may be manufactured, for example, by melt-kneading and then pulverizing and classifying to obtain a predetermined average particle size.

Further, in the toner of the present invention, generally used waxes can be appropriately added for the purpose of further improving the fixing property and the non-offset property, and in particular, a low molecular weight polyolefin wax is used. preferable. The amount of waxes added is 0.5 to 5 with respect to the toner.
The range of wt% is preferable, and the range of 1 to 3 wt% is more preferable. This is because the amount of waxes added is 0.5
This is because if it is less than 5% by weight, the effect of addition is not sufficient, and conversely if it exceeds 5% by weight, the fluidity of the toner tends to decrease.

[0025]

The present invention will be specifically described below with reference to examples. THF-insoluble matter: Celite (Celite 54 manufactured by Katayama Chemical Co., Ltd.
5) Glass filter filled with (1G-3 or 2G)
The weight (W1) of -3) was weighed, and 50 ml of THF was added to about 0.5 g of the resin (W2) in this glass filter. Then, the mixture was heat-treated at 60 ° C. for 3 hours, charged with a THF solution, and suction-filtered. The THF insoluble matter remaining on the glass filter was completely washed off with acetone, and the glass filter filled with Celite was vacuum dried at 80 ° C. for 3 hours or more, and then the weight (W3) of the glass filter was weighed. The THF insoluble content was calculated by the following formula (2).

[0026]

## EQU00004 ## THF insoluble matter = (W3-W1) / W2 (2) Softening temperature: using a flow tester (CFT-500 manufactured by Shimadzu Corporation) having a nozzle of 1 mmφ × 10 mm, load 30 Kgf, temperature rise It is shown as the temperature when 1/2 of the sample amount flows out under the condition of the speed of 3 ° C./min. Glass transition temperature: After the sample was heated to 100 ° C. and melt-quenched, the DSC method (heating rate 10 ° C./min)
It was calculated from the shoulder value.

Weight average molecular weight (Mw), elution start time (Ts), top elution time (Tt) and elution end time (Te): 0.04 wt% resin solution using THF as a solvent was added to a PTFE membrane (Tosoh Corporation). Company's My-Short Disk H-
25-5), and three columns (Tosoh TSK)
Gel permeation chromatography (HCL-80 manufactured by Tosoh Corporation) composed of gel / GMH _XL column)
20) measured at a temperature of 38 ° C. according to F2000 / F7
00 / F288 / F128 / F80 / F40 / F20 /
It was determined by polystyrene conversion with a calibration curve using F2 / A1000 (polystyrene manufactured by Tosoh Corporation) and a styrene monomer.

Fixing temperature range and image fogging: An unfixed image obtained by using a copying machine (FP-1570 manufactured by Matsushita Electric Industrial Co., Ltd.) is a fixing tester capable of freely changing the process speed and the roller temperature. It is used for fixing at a process speed of 200 mm / sec.
Rubbing with sand eraser 9 times in accordance with No. 12, the image density before and after that was measured using a Macbeth densitometer, the minimum fixing temperature at which the image density reduction rate is less than 20%, and the process speed of 100 mm in the same manner. The minimum fixing temperature at which the toner migrates to the roller when the toner is fixed using a fixing tester at 1 / sec. As for the image fog, the white portion of the image obtained by the evaluation in the fixing temperature region was visually observed.

Example 1 The weight average molecular weight was 380000, the elution start time (Ts) by GPC was 18.37 minutes, and the top elution time (T
t) is 23.65 minutes, elution end time (Te) is 24.9.
High molecular weight polymer component of 4 minutes and weight average molecular weight of 9
It is composed of a low molecular weight polymer component having a weight average molecular weight of 1,000, a THF insoluble content of 10.3% by weight, and a glass transition temperature of 61.
A styrene-based copolymer having a temperature of 5 ° C and a softening temperature of 128 ° C was prepared. 93 parts by weight of this styrene-based copolymer, 4 parts by weight of carbon black, 1 part by weight of a charge control agent for negative charging and 2 parts by weight of a polyolefin wax were mixed and melt-kneaded at 145 ° C. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 13 μm. The obtained toner had a fixing temperature range of 130 to 230 ° C. and was at a practical level, and no image fog was observed.

Example 2 Weight average molecular weight was 420,000, elution start time (Ts) by GPC was 18.22 minutes, and top elution time (T
t) is 23.62 minutes and elution end time (Te) is 24.7.
A high molecular weight polymer component that is 2 minutes and a weight average molecular weight of 1
000 and a low molecular weight polymer component, THF
Contains 11.6% by weight of insoluble matter and has a glass transition temperature of 5
A styrene-based copolymer having a temperature of 8.5 ° C. and a softening temperature of 124 ° C. was prepared. 93 parts by weight of this styrene-based copolymer, 4 parts by weight of carbon black, 1 part by weight of a charge control agent for negative charging, and 2 parts by weight of a polyolefin-based wax were mixed to prepare 145
Melt kneading was carried out at ℃. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 13 μm. The obtained toner has a fixing temperature range of 140 to 230.
The image was at a practical level at 0 ° C, and no image fog was observed.

Example 3 Weight average molecular weight of 450,000, elution start time (Ts) by GPC was 18.05 minutes, top elution time (T)
t) is 23.49 minutes, elution end time (Te) is 24.8.
High molecular weight polymer component of 9 minutes and weight average molecular weight of 1
000 and a low molecular weight polymer component, THF
It contained 7.7% by weight of insoluble matter and had a glass transition temperature of 59.
A styrene-based copolymer having a temperature of 0 ° C. and a softening temperature of 129 ° C. was prepared. 93 parts by weight of this styrene-based copolymer, 4 parts by weight of carbon black, 1 part by weight of a charge control agent for negative charging and 2 parts by weight of a polyolefin wax were mixed and melt-kneaded at 145 ° C. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 13 μm. The obtained toner had a fixing temperature range of 130 to 230 ° C. and was at a practical level, and no image fog was observed.

Comparative Example 1 The weight average molecular weight was 450,000, the elution start time (Ts) by GPC was 18.04 minutes, and the top elution time (T
t) is 21.83 minutes, elution end time (Te) is 26.6.
High molecular weight polymer component of 7 minutes and weight average molecular weight of 5
000, a low molecular weight polymer component, containing 0.03% by weight of THF insoluble matter, and having a glass transition temperature of 57.
A styrene-based copolymer having 0 ° C. and a softening temperature of 132 ° C. was prepared. 93 parts by weight of this styrene-based copolymer, 4 parts by weight of carbon black, 1 part by weight of a charge control agent for negative charging and 2 parts by weight of a polyolefin wax were mixed and melt-kneaded at 145 ° C. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 13 μm. The obtained toner had a fixing temperature range of 170 to 210 ° C., which was not a practical range, and image fogging was also observed.

Comparative Example 2 The weight average molecular weight was 340000, the elution start time (Ts) by GPC was 18.43 minutes, and the top elution time (T
t) is 21.22 minutes and elution end time (Te) is 26.1.
High molecular weight polymer component of 3 minutes and weight average molecular weight of 7
000, a low molecular weight polymer component, containing 0.04% by weight of THF insoluble matter, and having a glass transition temperature of 58.
A styrene-based copolymer having a temperature of 0 ° C. and a softening temperature of 130 ° C. was prepared. 93 parts by weight of this styrene-based copolymer, 4 parts by weight of carbon black, 1 part by weight of a charge control agent for negative charging and 2 parts by weight of a polyolefin wax were mixed and melt-kneaded at 145 ° C. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 13 μm. In the obtained toner, image fog was not recognized,
The fixing temperature range was 170 to 210 ° C., which was not a practical range.

[0034]

INDUSTRIAL APPLICABILITY The present invention provides a toner having an excellent balance between fixing property and non-offset property by controlling the molecular weight and melting property of the high molecular weight polymer component constituting the binder resin contained in the toner. Can be provided.

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

Claims (2)

[Claims] 1. A styrene-based copolymer comprising a high-molecular weight polymer component and a low-molecular weight polymer component and containing 0.1 to 50% by weight of THF insoluble matter, which is a high-molecular-weight polymer component that can be dissolved in THF. The weight average molecular weight of the solute is 200,000 to 60
And the weight average molecular weight of the THF-soluble component of the low molecular weight polymer component is 6,000 to 30,000, and the elution start time (Ts) in gel permeation chromatography of the high molecular weight polymer component is The top elution time (Tt) and elution end time (Te) are as follows (1)
A resin for toner, which satisfies the relationship of the formula. ## EQU1 ## Ts-Tt ≧ Tt-Te (1) 2. A toner comprising the styrene-based copolymer according to claim 1 as a binder resin.