JP2000075542A - Binder resin for toner and toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a binder resin for a toner and a toner having excellent balance in fixing property and non-offset property, good stability of image density, and blocking resistance. SOLUTION: This binder resin consists of a vinyl polymer having <=0.5 wt.% THF(tetrahydrofuran)-insoluble component. The mol.wt. distribution measured by GPC(gel permeation chromatography) of the THF-soluble component shows at least one peak in the region from 2×103 to 1.2×104 mol.wt., at least one peak in the region from 1×105 to 1×106 mol.wt., and at least one peak or shoulder in the region over 1×106, and has 50 to 70 deg.C glass transition temp.

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 a toner which has an excellent balance between fixing property and non-offset property, and has good image density 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 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 copolymers are frequently used, and linear (non-crosslinked) resins and crosslinked resins are used. 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 as disclosed in JP-B-63-32180, etc., and the glass transition temperature of both components is mixed. And the molecular weight distribution (Mw / M) of the entire resin as disclosed in JP-B-55-6895.
Attempts have been made to improve the fixing property and non-offset property of the toner by controlling n).

[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. In addition, since the dispersibility of the pigment or the like is poor, it is necessary to disperse the pigment by a high shear force. As a result, there is a problem that the crosslinked structure is cut and the non-offset property is reduced. On the other hand, a toner using a linear-type toner binder resin has good dispersibility of pigments and the like, but, for example, when the fixing property is improved, the melt viscosity of the toner binder resin is reduced, and the toner is not offset. Therefore, it was difficult to obtain toner having a good balance between the two.

Therefore, as proposed in Japanese Patent Publication No. 3-48506, an ultra-high molecular weight polymer component is further mixed with a mixture of a low molecular weight polymer component and a high molecular weight polymer component to form a toner. Attempts have been made to improve the balance between fixing properties and non-offset properties. However, the toner binder resin proposed in Japanese Patent Publication No. 3-48506 is inferior in the dispersibility of additives such as a colorant and a charge control agent at the time of forming a toner, so that the charging characteristics of the toner deteriorate. And the image density was poor in stability.
Further, the balance between the fixing property and the non-offset property as the toner was not sufficiently satisfactory. SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner binder resin and a toner which are excellent in balance between toner fixing property and non-offset property, and have good image density stability and blocking resistance.

[0007]

In view of such a situation, the present inventors have made intensive studies on a binder resin for a toner. As a result, by controlling the molecular weight of the binder resin, particularly the molecular weight in a low molecular weight region, the toner has been developed. It has been found that a binder resin for toner having an excellent balance between fixing property and non-offset property as well as good image density stability and blocking resistance can be obtained.

That is, the binder resin for a toner of the present invention is a vinyl polymer having a tetrahydrofuran-insoluble content of 0.5% by weight or less, and has a molecular weight distribution by gel permeation chromatography of a tetrahydrofuran-soluble content. Molecular weight 2 × 10 ^{3 to} 1.2 × 1
0 to ⁴ regions has at least one peak, at least one peak molecular weight in the region of ^{1 × 10 5 ~1 × 10 6} , at least one peak in the region where molecular weight is more than 1 × 10 ⁶ or It has a shoulder and a glass transition temperature of 50 to 70 ° C.
Further, the toner of the present invention contains the binder resin as described above.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The binder resin for toner of the present invention is a vinyl polymer having a tetrahydrofuran insoluble content of 0.5% by weight or less, and a styrene monomer and other copolymerizable vinyl resins. A styrene polymer polymerized from a monomer is preferable, and a styrene-acrylic copolymer polymerized from a styrene monomer and an acrylic monomer is particularly preferable. In the present invention, styrene monomers used for the polymerization of the vinyl polymer include styrene, o-methylstyrene, m-methylstyrene and p-methylstyrene.
-Methylstyrene, α-methylstyrene, p-ethylstyrene, 2,4-dimethylstyrene, pn-butylstyrene, p-tert-butylstyrene, pn-hexylstyrene, pn-octylstyrene, p -N-nonylstyrene, pn-densylstyrene, pn-dodecylstyrene, p-phenylstyrene, 3,4-dicyclosylstyrene, and the like, among which styrene is preferred. These styrenic monomers can be used alone or
It can be used in combination of more than one species.

Other copolymerizable vinyl monomers include ethyl acrylate, methyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, stearyl acrylate 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. Furthermore, 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 it is necessary to select such that the glass transition temperature of the obtained binder resin for toner is in the range of 50 to 70 ° C. This is because if the glass transition temperature of the binder resin for a toner is less than 50 ° C., the blocking occurrence temperature of the toner tends to decrease, and the storage stability tends to extremely decrease. And the fixability of the toner tends to decrease. The temperature is preferably in the range of 52 to 68 ° C, and more preferably in the range of 55 to 65 ° C. In the present invention, by controlling the molecular weight distribution of the vinyl polymer constituting the binder resin for the toner, a balance between the fixing property and the non-offset property is obtained, and a toner having excellent blocking resistance and image density stability is obtained. It can be provided. In particular, by setting the molecular weight of the low molecular weight region appropriately low,
The present invention can provide a toner having a good balance between blocking resistance and fixing property. That is, in the molecular weight distribution by gel permeation chromatography (GPC) of the tetrahydrofuran-soluble portion of the binder resin for toner, the region (A) having a molecular weight of 2 × 10 ^{3 to} 1.2 × 10 ^4.
Has a peak in a region (B) having a molecular weight of 1 × 10 ⁵ to 1 × 10 ⁶ , and has a peak or a shoulder in a region (C) having a molecular weight of 1 × 10 ⁶ or more.

The component in the region A is a component that contributes to the fixability of the toner, and the peak of the component in this region is 2 × 10
^If it is less than ³ , the blocking resistance of the toner tends to decrease, and the tackiness of the toner tends to be high and the non-offset property tends to be inferior. Also, the peak is 1.2 × 10 ⁴
If the ratio exceeds the range, the fixability of the toner tends to decrease. The component of the region A is preferably 2.3 × 10 ³ to
The peak has an area of 1.1 × 10 ⁴ , and more preferably has a peak in an area of 3.5 × 10 ^{3 to} 1.0 × 10 ⁴ . The component in the region B is a component that contributes to the non-offset property and strength of the toner. If the peak value of the component in this region is less than 1 × 10 ⁵ , the strength of the toner decreases and the fixed image is rubbed or bent. In the event that they are missing. Conversely, if the peak value exceeds 1 × 10 ⁶ , the softening temperature of the toner tends to increase, and the fixability tends to decrease. The peak of the component in the region B is preferably 1 × 1
0 ⁵ to 8 × 10 ⁵ , more preferably 1.
It is an area of 2 × 10 ^{5 to} 5 × 10 ⁵ . The component of the region C is a component that contributes to the non-offset property, and is 1 × 10 ⁶
If there is no peak or shoulder in the region exceeding the range, the non-offset property tends to be impaired, and is preferably a region of 1.2 × 10 ⁶ or more, more preferably a region of 1.3 × 10 ⁶ or more.

In the present invention, the content of the component in region C having a peak or shoulder in a region of 1 × 10 ⁶ or more is preferably less than 10% by weight, more preferably 8% by weight or less. . This is because, by setting the content of the component in the region C to less than 10% by weight, the additives such as the colorant, the charge control agent and the release agent as the toner are sufficiently mixed with the binder resin, and the image density is reduced. This is because the stability can be further improved.

The binder resin for toner of the present invention has an insoluble content of tetrahydrofuran of 0.5% by weight or less.
This is because if the tetrahydrofuran insoluble content exceeds 0.5% by weight, the miscibility with a coloring agent, a charge controlling agent, a release agent, etc. added during toner formation is reduced, and the image density stability of the toner is reduced. Is preferably impaired, preferably in a range of 0.4% by weight or less, more preferably 0.3% by weight.
The range is as follows.

The binder resin for a toner of the present invention is obtained by subjecting a mixture of the above polymerizable monomers to an emulsion polymerization method, a suspension polymerization method,
It can be produced by polymerizing by a general method such as a bulk polymerization method or a solution polymerization method. Among them, the suspension polymerization method is preferred 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 the present invention, a magnetic toner, a non-magnetic toner, a one-component toner,
It can be used as a binder resin for various toners such as a component toner. In particular, in a two-component toner, the binder resin as described above is preferably contained in the toner in the range of 80 to 97% by weight, and more preferably in the range of 90 to 95% by weight. This is because when the content of the binder resin is less than 80% by weight, the non-offset property of the toner tends to decrease, and when it exceeds 97% by weight, the charging stability of the toner tends to deteriorate. is there.

The toner of the present invention is prepared by adding additives such as a wax, a colorant, a pigment, a charge control agent, an anti-offset agent, and a magnetic powder together with a binder resin using a kneader such as a twin-screw extruder or a mixer. After kneading at a temperature about 15 to 30 ° C. higher than the softening temperature of the binder resin,
Classification is performed to form a toner. The average particle diameter of the obtained toner particles is preferably about 5 to 20 μm, and more preferably about 8 to 15 μm.

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 wax such as polypropylene wax ( It is preferably 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 first yellow, lithol red, permanent orange 4R, etc. Charge control of colorants or pigments, nigrosine, alkyl-containing azine dyes, basic dyes, monoazo dyes or their metal complexes, salicylic acid or its metal complexes, alkylsalicylic acid or its metal complexes, naphthoic acid or its metal complexes, etc. Agent,
Examples include an anti-offset agent such as polyethylene, polypropylene, and ethylene-polypropylene copolymer, and a magnetic powder such as ferrite and magnetite.

[0019]

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) insoluble : Celite 54
5 (Katayama Chemical Co., Ltd.) filled glass filter (1G
-3 or 2G-3) was weighed (W1), 0.5 g of resin (W2) was added to 50 ml of THF in the glass filter, and the mixture was heated at 60 ° C. for 3 hours.
The THF solution is suction filtered. Next, the THF-insoluble matter remaining on the glass filter was completely washed away with acetone, vacuum-dried at 80 ° C. for 3 hours or more, and the weight (W3) of the glass filter was weighed. ).

[0020]

## EQU1 ## THF-insoluble matter (%) = {(W3-W1) × 100} / W2 (1) For gel permeation chromatography (GPC)
Molecular weight distribution : 0.4% by weight of a resin solution using THF as a solvent is applied to a PTFE membrane (Myshodisc H, manufactured by Tosoh Corporation).
-25-5) and filtered through three columns (TSO Corporation TS
Gel permeation chromatography (HCL-8 manufactured by Tosoh Corporation) composed of Kgel / GMH _XL column)
020) at a temperature of 38 ° C. and F2000 / F
700 / F288 / F128 / F80 / F40 / F20
/ F2 / A1000 (polystyrene manufactured by Tosoh Corporation) and a calibration curve using a styrene monomer were determined in terms of polystyrene. The measurement temperature was 38 ° C and the detector was R
I.

Glass transition temperature : The shoulder value in DSC measurement after melting and quenching a sample at 100 ° C. was adopted. Fixing temperature range : Commercial copying machine (PRESAGE manufactured by Toshiba Corporation)
251), the unfixed image obtained at a fixing speed of 300 mm / sec was rubbed 9 times with a sand eraser (JIS 512) using a fixing tester with a variable roller temperature. The image density was measured with a Macbeth densitometer, and indicated by the lowest temperature at which the decrease in density was less than 20% and the lowest temperature at which toner transferred to the roller.

The fixability: Based on the measurement results of the fixing temperature range was evaluated according to the following criteria. ：: Good fixability. Δ: Slightly inferior in fixability, but at a practical level. X: Poor fixability.

Non-offset property : Based on the measurement results in the fixing temperature range, evaluation was made according to the following criteria. ：: Good non-offset property. Δ: Somewhat inferior in non-offset properties, but at a practical level. ×: Non-offset property is poor.

Image density stability : A running test of 10,000 sheets was performed using a commercially available copying machine (PREMAG251 manufactured by Toshiba Corporation), and the image density (D ₁ ) of the first sheet and the image density (D) of the 10,000 sheet ₁₀₀₀₀ ) was measured with a Macbeth densitometer, the rate of change was calculated according to the following equation (2), and evaluated according to the following criteria.

[0025]

(| D ₁ −D ₁₀₀₀₀ | / D ₁ ) × 100 (%) (2) ：: The rate of change is less than 5%. Δ: Change rate of 5 to 10%. X: The rate of change exceeds 10%.

Image fog : The image obtained in the evaluation of image density stability was visually evaluated according to the following criteria. ：: No fog. Δ: Fog is slightly observed, but at a practical level. ×: Significant fog.

Blocking resistance : After the toner was put in a glass bottle and allowed to stand at 50 ° C. for 16 hours, the state of blocking was visually evaluated according to the following criteria. ：: No blocking occurred. Δ: Blocking occurs slightly, but at a practical level. X: Blocking is remarkable.

Example 1 The following three copolymers were melted and mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 8400) Styrene / acrylic n-butyl copolymer 35% by weight (monomer weight ratio = 80: 20, weight average) Styrene / acrylic n-butyl copolymer 15% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 1790,000) The obtained styrene-acrylic copolymer was used as a binder resin to 93% by weight. 4% by weight of carbon black (# 40 manufactured by Mitsubishi Kasei), 1% by weight of a charge control agent ("Bontron S-34" manufactured by Orient Chemical Industries) and 2% by weight of polypropylene wax (660P manufactured by Sanyo Chemical) are blended, The mixture was melt-kneaded at 135 ° C. using a twin-screw extruder. Next, it was pulverized using a jet mill pulverizer and classified to obtain a toner having an average particle diameter of 13 μm. Measurement of the fixing temperature range of the obtained toner, evaluation of fixing property, non-offset property, blocking resistance, image fog, image density stability,
The results are shown in Table 1.

Example 2 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 8400) Styrene / acrylic n-butyl copolymer 40% by weight (monomer weight ratio = 80: 20, weight average) Styrene / acrylic n-butyl copolymer 10% by weight (monomer weight ratio = 80:20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 3 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 8400) Styrene / acrylic n-butyl copolymer 42% by weight (monomer weight ratio = 80: 20, weight average) Styrene / acrylic n-butyl copolymer 8% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 1790,000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 4 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 8400) Styrene / acrylic n-butyl copolymer 44% by weight (monomer weight ratio = 80: 20, weight average) Styrene / acrylic n-butyl copolymer 6% by weight (monomer weight ratio = 80:20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 5 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 83: 17, weight average molecular weight = 11000) Styrene / acrylic n-butyl copolymer 42% by weight (monomer weight ratio = 83: 17, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 83: 17, weight average molecular weight = 1650000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 6 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 60% by weight (monomer weight ratio = 89: 11, weight average molecular weight = 12000) Styrene / acrylic n-butyl copolymer 35% by weight (monomer weight ratio = 85: 15, weight average) Styrene / acrylic n-butyl copolymer 5% by weight (monomer weight ratio = 80:20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 7 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 57% by weight (monomer weight ratio = 89: 11, weight average molecular weight = 12000) Styrene / acrylic n-butyl copolymer 35% by weight (monomer weight ratio = 86: 14, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1790,000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 8 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene / acrylic n-butyl copolymer 60% by weight (weight ratio of monomer = 89: 11, weight average molecular weight = 12000) Styrene / acrylic n-butyl copolymer 32% by weight (monomer weight ratio = 89: 11, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 9 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 95: 5, weight average molecular weight = 4700) Styrene / acrylic n-butyl copolymer 42% by weight (monomer weight ratio = 80: 20, weight average) Styrene / acrylic n-butyl copolymer 8% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 1790,000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 10 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene polymer 50% by weight (weight average molecular weight = 2800) Styrene / acrylic n-butyl copolymer 42% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 296000) Styrene / acrylic n-butyl copolymer 8 % By weight (monomer weight ratio = 80:20, weight average molecular weight = 1790000) A toner having an average particle diameter of 13 µm was obtained in the same manner as in Example 1 using the obtained styrene-acrylic copolymer as a binder resin. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 11 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene / acrylic n-butyl copolymer 55% by weight (monomer weight ratio = 95: 5, weight average molecular weight = 4700) Styrene / acrylic n-butyl copolymer 37% by weight (monomer weight ratio = 79: 21, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1800000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 12 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 60% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 13000) Styrene / acrylic n-butyl copolymer 32% by weight (monomer weight ratio = 80: 20, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 13 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 60% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 14500) Styrene / acrylic n-butyl copolymer 32% by weight (monomer weight ratio = 80: 20, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 14 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 60% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 15800) Styrene / acrylic n-butyl copolymer 32% by weight (monomer weight ratio = 80: 20, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Example 15 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 8400) Styrene / acrylic n-butyl copolymer 47% by weight (monomer weight ratio = 80: 20, weight average) Styrene / acrylic n-butyl copolymer 3% by weight (monomer weight ratio = 80:20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Comparative Example 1 The following two copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 8400) Styrene / acrylic n-butyl copolymer 50% by weight (monomer weight ratio = 80: 20, weight average) (Molecular weight = 296000) A toner having an average particle diameter of 13 μm was obtained in the same manner as in Example 1 using the obtained styrene-acrylic copolymer as a binder resin. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Comparative Example 2 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene polymer 50% by weight (weight average molecular weight = 2100) Styrene / acrylic n-butyl copolymer 42% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 296000) Styrene / acrylic n-butyl copolymer 8 % By weight (monomer weight ratio = 80:20, weight average molecular weight = 1790000) A toner having an average particle diameter of 13 µm was obtained in the same manner as in Example 1 using the obtained styrene-acrylic copolymer as a binder resin. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Comparative Example 3 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1. Styrene / acrylic n-butyl copolymer 60% by weight (monomer weight ratio = 80: 20, weight average molecular weight = 17000) Styrene / acrylic n-butyl copolymer 32% by weight (monomer weight ratio = 80: 20, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1790000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

Comparative Example 4 The following three copolymers were melt-mixed to obtain a binder resin. THF-insoluble content of the obtained binder resin, GPC
Was measured for the molecular weight distribution and the glass transition temperature by the method described in Table 1, and the results are shown in Table 1. Styrene / acrylic n-butyl copolymer 55% by weight (monomer weight ratio = 95: 5, weight average molecular weight = 4700) Styrene / acrylic n-butyl copolymer 37% by weight (monomer weight ratio = 77: 23, weight average) 8 wt% of styrene / acrylic n-butyl copolymer (monomer weight ratio = 80: 20, weight average molecular weight = 1800000) Same as Example 1 using the obtained styrene-acrylic copolymer as a binder resin Thus, a toner having an average particle diameter of 13 μm was obtained. Measurement of the fixing temperature range of the obtained toner,
Fixing properties, non-offset properties, blocking resistance, image fog, and image density stability were evaluated. The results are shown in Table 1.

[0047]

[Table 1]

[0048]

According to the present invention, a binder for toner which is excellent in balance between fixing property and non-offset property as toner and has good image density stability and blocking resistance by controlling the molecular weight of the binder resin. −
Resin and toner can be provided.

 ────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Masaru Sugiura 2-1-1, Ushikawa-dori, Toyohashi-shi, Aichi F-term (reference) in the Toyohashi Plant of Mitsubishi Rayon Co., Ltd. 2H005 AA01 CA04 DA06 DA10 EA03 EA06 EA07

Claims (3)

[Claims] 1. A vinyl polymer having a tetrahydrofuran-insoluble content of 0.5% by weight or less, wherein a molecular weight distribution of a tetrahydrofuran-soluble component is 2 × 10 ³ to 2 × 10 ^{3 in} a gel permeation chromatography.
It has at least one peak in a region of 1.2 × 10 ⁴ , has at least one peak in a region of a molecular weight of 1 × 10 ⁵ to 1 × 10 ⁶ , and has at least a peak in a region of a molecular weight exceeding 1 × 10 ^6. Has one peak or shoulder,
A binder resin for a toner having a glass transition temperature of 50 to 70 ° C. 2. A compound having a molecular weight of more than 1 × 10 ⁶
2. The binder resin for a toner according to claim 1, wherein the amount is less than 10% by weight. 3. A toner comprising the binder resin according to claim 1.