JPH08220803A - Production of styrene based copolymer for toner - Google Patents

Abstract

PURPOSE: To obtain a toner having excellent low-temp. fixability and high-temp. offsettability by adding a specific vinyl based mixture to a specific styrene based polymer dispersion and subjecting the dispersion to suspension polymn. CONSTITUTION: The vinyl based monomer mixture contg. a vinyl based monomer having >=2 pieces of non-conjugate double bonds is added into a dispersion dispersed with the styrene based polymer having a weight average mol.wt. of 5,000 to 20,000 and the suspension is subjected to suspension polymn. The content of the vinyl based monomer having >=2 pieces of the non-conjugate double bonds in the vinyl monomer mixture is preferably 0.01 to 0.3wt.%. The styrene based polymer is preferably produced by a suspension polymn. method and the weight ratio of the ethylene based polymer and the vinyl based monomer mixture is preferably 80:20 to 50:50. Further, the styrene based polymer for toners and coloring agents are melted and kneaded and the mixture is preferably subjected to cooling, pulverizing and classifying. As a result, the toner having the low-temp. fixability and excellent high-temp. offsettability is obtd.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing a styrene-based copolymer for toner used in electrophotography.

[0002]

2. Description of the Related Art In recent years, as the information-oriented society has advanced, the speed of information processing is required more and more, and the energy saving of offices is required. High-speed copying and energy saving of copiers require physical properties that can support high-speed copying of toner resin, and low temperature fixability is a symbol of this (a toner image can be fused and fixed on a transfer sheet such as paper at a low temperature). ), Improvement in high temperature offset property (resistance to “offset phenomenon” in which a part of toner transferred to a transfer sheet such as paper further transfers to a fixing roller). Toners that are consumed in large quantities must also be safe and inexpensive.

Many methods have hitherto been proposed as a method for producing a resin for toner. For example, JP-A-64-885
No. 56 discloses a bulk polymerization of a polymerization rate of 30 to 90% by weight.
Then, a solvent is added to carry out solution polymerization, and the solvent is removed to obtain a Z-average molecular weight (hereinafter abbreviated as “MZ”) of 400,000 or more and a number-average molecular weight (hereinafter abbreviated as “MN”) of 2, 0
There has been proposed a method for providing a toner resin having an offset property of 00 to 15,000 and MZ / MN of 50 to 600. In Japanese Examined Patent Publication No. 2-47747, a comonomer having two or more non-conjugated double bonds, 0.
0.5 to 2 wt% is copolymerized and contained, and Mn is 1,0
The weight average molecular weight (hereinafter, "M
W)) and MN ratio MW / MN is 45 to 100, and the toner using a copolymer as a binder is excellent in fixing property and offset resistance.

[0004]

However, there is a demand for a resin having properties even better than those of conventional toner resins. An object of the present invention is to provide a toner excellent in low temperature fixing property and high temperature offset property by stabilizing physical properties by a more precise polymerization method of a toner resin. Another object is to avoid the use of high temperature, high pressure, highly viscous fluid, and flammable solvent, and to manufacture the resin for toner under the mild conditions by the suspension polymerization method to avoid the quality variation.

[0005]

Means for Solving the Problems As a result of earnest studies to achieve the above-mentioned problems, the present inventor has found that in the presence of a prepolymerized low molecular weight styrene polymer (hereinafter abbreviated as “low molecular weight material”). The present invention has been completed by finding a method for producing a styrene-based copolymer for toner which is excellent in low-temperature fixability by producing a high-molecular weight polymer. That is, the gist of the present invention is to add a non-conjugated double bond to a dispersion liquid in which a styrene polymer having a weight average molecular weight of 5,000 to 20,000 (hereinafter, abbreviated as "low molecular weight substance") is dispersed. A method for producing a styrene-based copolymer for a toner, comprising adding a vinyl-based monomer mixture containing two or more vinyl-based monomers and performing suspension polymerization. The present invention will be described in detail below.

The production method of the present invention particularly contains 60 to 98% by weight of tetrahydrofuran insoluble matter, and the tetrahydrofuran (hereinafter abbreviated as "THF") soluble matter has a Z average molecular weight of 450,000 to 2,000,000 and a Z average molecular weight. The ratio (MZ / MN) of (MZ) to number average molecular weight (MN) is 50 to 25.
0, and the melt flow index (hereinafter "MFI")
Abbreviated) is 0.2 to 10 g / 10 min for producing a styrene-based copolymer for toner.

The above-mentioned styrene-based copolymer is usually a cross-linked polymer, and MZ and MN are gel permeation chromatography (hereinafter referred to as "GPC") of a THF-soluble component of the styrene-based copolymer used as a toner or a raw material. It is an analysis value. When MZ is 450,000 or less, high temperature offset is likely to occur, and in terms of high temperature offset property, MZ is up to 2 million, and if it is more than that, manufacturing becomes difficult. The styrene-based copolymer has a THF insoluble content of 60
%, The whole image of the copolymer cannot be defined only by the GPC analysis value of the THF-soluble content. Therefore, the present inventors have found that MFI, which represents the melting behavior of the styrene-based copolymer, is a very important index, and that MFI smaller than the conventional styrene-based copolymer for toner is preferable. The preferred MFI is 0.2 to 7 g / 10 min, more preferably 0.8 to 3 g / 10 min. MFI
If the value is too small, the load on the extruder and the like at the time of melt-kneading in toner production increases, and the productivity of the toner decreases. If the MFI is too large, pigments and the like are likely to be poorly dispersed, and the toner is likely to be scattered in the copying machine and scumming during copying is likely to occur.

The MFI is a value obtained by applying a load of 5 kg at 150 ° C. The softening point (hereinafter abbreviated as "Ts") of the styrene-based copolymer is 125 to 170 ° C, and particularly preferably 130 to 160 ° C. The glass transition point (hereinafter abbreviated as “Tg”) is preferably 50 ° C. or higher in view of storage stability, and is preferably 75 ° C. or lower in view of fixing property. In addition, Ts is defined as a temperature at which the amount of depression of the plunger becomes 1/2, and Tg is a value measured by a DSC manufactured by DuPont.

The low molecular weight compound is synthesized by any synthesis method such as bulk polymerization, solution polymerization, dispersion polymerization and suspension polymerization of styrene, acrylic acid ester, methacrylic acid ester and the like, but suspension polymerization is particularly suitable. There is. The MW of the low molecular weight substance is 5,000 to 20,000. 5,000
In the following, it is necessary to increase the amount of polymerization initiator,
When it is 00 or more, the low temperature fixability becomes insufficient. MW is 5,
000 to 15,000 is more preferable. Polystyrene, poly (styrene / butyl acrylate) and the like are preferably used as the low molecular weight substance.

The vinyl monomer mixture to be added to the dispersion of the low molecular weight substance is a vinyl monomer having two or more non-conjugated double bonds (hereinafter abbreviated as "crosslinkable monomer").
In the vinyl-based monomer mixture containing, the vinyl-based monomer other than the crosslinkable monomer is preferably styrene, acrylic acid ester, methacrylic acid ester, or the like. Examples of the crosslinkable monomer include benzenes such as divinylbenzene, ethylene glycol dimethacrylate, tetramethylene glycol dimethacrylate, 1,
There are (meth) acrylates such as 3-butanediol dimethacrylate, 1,6-hexanediol diacrylate and allyl methacrylate, and tetramethylene glycol dimethacrylate and 1,6-hexanediol diacrylate are preferable.

The crosslinkable monomer is 0.01 to 0.
It is preferable to contain 3% by weight. More preferably,
0.01 to 0.25% by weight is contained. Too little,
MFI becomes large, toner offset is likely to occur at high temperatures, and toner is often scattered in the copying machine and fog (background stain) on a white background at the time of copying. On the other hand, if the amount is too large, the melt viscosity at the time of toner production becomes high, the pigment, the charge control agent, the release agent and the like are likely to be poorly dispersed, and the fixing temperature becomes high.

The suspension polymerization carried out by adding the vinyl monomer mixture may be adjusted so that the styrene copolymer having the above-mentioned specific physical properties can be obtained. Hereinafter, preferable conditions will be described. The polymerization initiator is preferably an organic peroxide having a 10-hour half-life temperature of about 60 to 98 ° C. Two or three types of organic peroxides having different half-life temperatures can be used in combination. Specific examples include lauroyl peroxide, benzoyl peroxide, tert-butylperoxyisobutyrate, tert-butylperoxylaurate, tert-butylperoxyisopropyl carbonate, 1,1-bis (tert-butylperoxy). 3,3,5-trimethylcyclohexane,
2,2-bis (4,4-di-tert-butylperoxycyclohexyl) propane, 1,1,2-trimethylpropylperoxy-2-ethylhexanoate and the like can be mentioned. The amount of the polymerization initiator used is preferably 0.1 to 1.0% by weight based on the vinyl monomer mixture. The polymerization initiator is preferably used by dissolving it in the vinyl monomer mixture, but it may be dissolved in a small amount of an organic solvent and added to the polymerization system. It can also be dispersed in water and added.

The addition of the vinyl-based monomer mixture is preferably carried out continuously or intermittently over 30 to 180 minutes into the polymerization system in which the low molecular weight substance is dispersed. If they are added all at once at the beginning of the polymerization, aggregation and precipitation of dispersed particles easily occur, which is not preferable. As the dispersant used in the polymerization, water-soluble polymers such as PVA, polyacrylic acid, polymethacrylamide, and polyvinylpyrrolidone, and inorganic compounds such as talc, calcium carbonate and calcium phosphate are preferable.

The polymerization temperature is preferably 60 to 98 ° C. Furthermore, it is more preferable that the half-life temperature is 10 hours or less. Even if it exceeds the 10-hour half-life temperature, it is preferably within 8 ° C. The polymerization time is preferably 4 to 20 hours. Here, the polymerization temperature and the polymerization time are temperatures and times until the polymerization of the vinyl-based monomer is substantially completed, and the post-polymerization for reducing a trace amount of the residual monomer is not included therein. The polymerization is completed when almost no residual monomer is present, but a trace amount of residual monomer can be removed by steam distillation or stripping. Water is generally used as the dispersion medium.

The styrene copolymer polymerized as described above is used for a toner binder after being purified by removing a dispersant and the like and then dried. On the other hand, the low molecular weight substance is preferably produced by a suspension polymerization method, and according to this production method, the production of the low molecular weight substance and the production of the styrene-based copolymer are carried out continuously. Because it can, the economic effect is great. The suspension polymerization method of the low molecular weight substance is not particularly limited. The dispersant used for the polymerization is PVA,
Water-soluble polymers such as polyacrylic acid, polymethacrylamide, and polyvinylpyrrolidone, and inorganic compounds such as talc, calcium carbonate, and calcium phosphate are preferable. Also, a small amount of surfactant may be used in combination.

The polymerization initiator used for the polymerization of the low molecular weight substance may be the same kind as the initiator used by blending with the above-mentioned vinyl monomer mixture. The polymerization initiator is preferably an organic peroxide having a 10-hour half-life temperature of about 60 to 98 ° C. Two or three types of organic peroxides having different half-life temperatures can be used in combination. Specific examples include lauroyl peroxide, benzoyl peroxide,
tert-butyl peroxyisobutyrate, tert
-Butylperoxylaurate, tert-butylperoxyisopropyl carbonate, 1,1,1-bis (tert-butylperoxy) 3,3,5-trimethylcyclohexane, 2,2-bis (4,4-di-) ter
t-butylperoxycyclohexyl) propane,
(1,1,2-Trimethylpropylperoxy-2-ethylhexanoate and the like can be mentioned. The amount of the polymerization initiator used is preferably 6 to 9% by weight based on the monomer. The polymerization temperature is preferably higher than the 10-hour half-life temperature by at least 15 ° C. The polymerization time is the time at which the polymerization of the low molecular weight substance is substantially completed, and preferably 1 to 10 hours.

The styrene-based copolymer of the present invention is produced by substantially completing the polymerization of the low-molecular weight product, and then adding the vinyl-based monomer mixture to continue the suspension polymerization. The weight ratio of the low molecular weight product to the vinyl-based monomer mixture added thereto is preferably 80:20 to 50:50. If the weight ratio of the low molecular weight substance is too large, the environmental stability of the toner tends to be poor, and if it is too small, the melt viscosity of the toner tends to be high, resulting in poor dispersion of the pigment and the like.

The styrene contained in the low molecular weight compound is 1
It is preferably from 0 to 80% by weight. When the content of styrene is too small, the storage stability (blocking) of the toner is lowered. The styrene content in the vinyl-based monomer mixture added to the low molecular weight product is determined in consideration of the glass transition temperature of the styrene-based copolymer and the like, and is preferably 80 to 50% by weight. If the styrene content is too low, the MFI becomes small, which is not preferable.

The essential point of the present invention is that when the polymerization reaction is carried out in the presence of a low molecular weight styrene polymer to produce a high molecular weight component, a crosslinking reaction is simultaneously carried out. A second important point of the present invention is that a production method excellent in quality stability, safety and economy is completed by carrying out the above-mentioned polymerization reaction under a mild suspension polymerization reaction. The styrene copolymer polymerized, purified and dried as described above is useful as a binder resin for toner. As a method for producing a toner, for example, a colorant such as a pigment, a charge control agent, and a release agent are mixed, and melt kneading, cooling, pulverizing, and classification are performed to produce a toner of about 10 microns. Further, a fluidizing agent such as fine particle silica may be added. The obtained toner may be mixed with a magnetic substance such as ferrite, iron powder, magnetite or the like to be an electrostatic image developer (two-component developer), or a magnetic substance may be blended in advance to obtain a magnetic toner.

By using the styrene copolymer obtained by the present invention, a toner excellent in low-temperature fixability, offset resistance and storage stability can be produced. In the present invention,
The molecular weight distribution of the polymer was measured by GPC using a conventional method. That is, prepare a 0.1 wt% THF solution,
Call the GPC device.

[0021]

[Table 1] Outline of the device Main body HLC-8020 (manufactured by Tosoh Corporation) Sampler AS-8000 (manufactured by Tosoh Corporation) Column Mix-M57-35 (manufactured by PL Corporation) Mix-M57-45 (manufactured by PL Corporation) Measurement condition 40 ° C 1 ml / min

In the present invention, the melt flow index (MFI) of the (co) polymer was measured using a melt indexer manufactured by Takara Industry Co., Ltd.

[0023]

[Table 2] Measurement conditions Sample amount 5.0 g Load 5.0 kgw Temperature 150.0 ° C

In the present invention, the softening point (Ts) of the (co) polymer was measured using a flow tester CFT-500 manufactured by Shimadzu Corporation.

[0025]

[Table 3] Measurement conditions Sample amount 1.00 g Load 30 kgw Heating rate 3.0 ° C / min Start temperature 80 ° C Nozzle 1 mm diameter, 10 mm length Definition of Ts Temperature at which plunger drop amount is 1/2 (° C)

In the present invention, the glass transition point of the (co) polymer was measured using DSC2000 manufactured by Dyupon.

[0027]

The present invention will be described in more detail with reference to the following examples. The low molecular weight compounds used in Examples 1 to 4 and Comparative Example 1 were
It was prepared as follows using the suspension polymerization method. 425 g of styrene, 75 g of butyl acrylate, and 50 g of benzoyl peroxide (purity 75%, 10-hour half-life temperature of 74 ° C.) are mixed and put in a dropping funnel. 1000 g deionized water,
30 g of tricalcium phosphate is placed in a 3 L separable flask and heated to 93 ° C. while flowing nitrogen. The monomer in which the initiator was dissolved was added dropwise from the dropping funnel over 1 hour. After continuing the reaction for further 7 hours, it was cooled and the polymer was filtered off. The tricalcium phosphate was removed by acid cleaning. Further, impurities were removed by alkali washing, and after washing with water, hot air drying was performed at 50 ° C. for 15 hours. The obtained low molecular weight product has MW of 14,000 and MN of 6,50.
It was 0. The amount of benzoyl peroxide used is 53.3 g,
MW of 13,000 (MN is 5,900) and 11,000 (M
A low molecular weight product having N of 5,600) was produced. Then, the low molecular weight substance was charged into a reactor together with a dispersant and water, and a vinyl monomer mixture containing a crosslinkable monomer was added thereto and polymerized to synthesize a styrene copolymer. The results are summarized in Table 1.

Example 1 250 g of a styrene / butyl acrylate copolymer having a MW of 14,000 (copolymerization ratio (weight ratio) 85/15), 30 g of calcium phosphate and 1,000 g of deionized water were placed in a 3 L 4-neck flask. Nitrogen replacement was carried out with stirring. When the temperature was controlled to 77 ° C, styrene 10
3.95 g, n-butyl acrylate 31.05 g,
0.2 g of 1,6-hexanediacrylate, 0.27 g of benzoyl peroxide (purity 75%), 2,2-bis (4
4'-di-tert-butylperoxycyclohexyl) propane (purity 20%, 10 hour half-life temperature 92
(° C.) 1 g was mixed and dissolved in advance and added dropwise over 1 hour.
After the dropping was completed, the polymerization reaction (post-polymerization) was continued at 77 ° C. for 4 hours and then at 94 ° C. for 4 hours. The physical properties of the obtained copolymer are as follows: MN 7,300, MW 910,000, MZ 66.
10,000, MZ / MN 90, MFI 1.1g / 10mi
n, Tg: 65 ° C., Ts: 143 ° C., THF insoluble matter: 9
It was 0%.

Example 2 250 g of a styrene / butyl acrylate copolymer having a MW of 11,000 (copolymerization ratio 85/15), 30 g of calcium phosphate and 1,000 g of deionized water were placed in a 3 L four-necked flask and stirred. While substituting with nitrogen. When the temperature was controlled to 77 ° C, 102.8 g of styrene, n
-Butyl acrylate 30.7 g, 1,6-hexanediacrylate 0.133 g, benzoyl peroxide (purity 7
5%) 0.27 g was premixed, dissolved and added dropwise over 1 hour. After the dropping was completed, the polymerization reaction was continued at 77 ° C. for 8 hours. The physical properties of the obtained copolymer are MN = 7,200 and M
W is 132,000, MZ is 1.32 million, MZ / MN is 18
3, MFI 3.6g / 10min, Tg 66 ° C, T
s was 140 ° C., and THF insoluble matter was 83%.

Example 3 250 g of a styrene / butyl acrylate copolymer having a MW of 11,000 (copolymerization ratio 85/15), 30 g of calcium phosphate and 1,000 g of deionized water were placed in a 3 L four-necked flask and stirred. While substituting with nitrogen. When the temperature was controlled to 77 ° C, 82.5 g of styrene, n-
Butyl acrylate 24.6 g, 1,6-hexanediacrylate 0.054 g, benzoyl peroxide (purity 75
%) 0.214 g were mixed in advance, dissolved, and added dropwise over 1 hour. After the dropping was completed, the polymerization reaction was continued at 77 ° C. for 8 hours. The physical properties of the obtained copolymer are as follows: MN = 7,500, M
W is 180,000, MZ is 1.5 million, MZ / MN is 200, M
FI is 8.9g / 10min, Tg is 70 ° C, Ts is 1.
The THF-insoluble matter was 61% at 36 ° C.

Example 4 250 g of a styrene / butyl acrylate copolymer having a MW of 13,000 (copolymerization ratio 85/15), 30 g of calcium phosphate and 1,000 g of deionized water were placed in a 3 L four-necked flask and stirred. While substituting with nitrogen. When the temperature was controlled to 77 ° C, 102.8 g of styrene, n
-Butyl acrylate 30.7 g, 1,6-hexanediacrylate 0.267 g, benzoyl peroxide (purity 7
0.267 g (5%) was mixed and dissolved in advance and added dropwise over 1 hour. After the dropping was completed, the polymerization reaction was continued at 77 ° C. for 8 hours. The physical properties of the obtained copolymer were MN of 7,200,
MW is 530,000, MZ is 530,000, MZ / MN is 71, M
The FI was 0.39 g / 10 min, the Tg was 70 ° C., the Ts was 160 ° C., and the THF insoluble content was 77%.

Comparative Example 1 250 g of a styrene / butyl acrylate copolymer having a MW of 13,000 (copolymerization ratio 85/15), 30 g of calcium phosphate and 1,000 g of deionized water were placed in a 3 L four-necked flask and stirred. While substituting with nitrogen. When the temperature was controlled to 77 ° C, 102.8 g of styrene, n
-Butyl acrylate 30.7 g, 1,6-hexanediacrylate 0.294 g, benzoyl peroxide (purity 7
0.267 g (5%) was mixed and dissolved in advance and added dropwise over 1 hour. After the dropping was completed, the polymerization reaction was continued at 77 ° C. for 8 hours. The physical properties of the obtained copolymer were such that MN was 7,000,
MW is 310,000, MZ is 230,000, MZ / MN is 33, M
The FI was 0.20 g / 10 min, the Tg was 70 ° C., the Ts was 162 ° C., and the THF insoluble content was 60%.

Using 100 parts of the styrene copolymer for toner obtained as described above as a binder, 6 parts of carbon black MA-100 (manufactured by Mitsubishi Chemical) and a charge control agent P-51 (manufactured by Orient Chemical) were used. 2 parts and 2 parts of polypropylene wax 550P (manufactured by Sanyo Chemical Co., Ltd.) were mixed and melt-kneaded using an extruder. The kneaded solid was finely pulverized and classified to obtain a toner. Further, 0.15% of Aerosil (manufactured by Nippon Aerosil) was added to this toner. 5% toner was added to iron powder and mixed to prepare a developer. 400 mm /
A fixing test was conducted at a speed of sec. In the blocking test, a load was applied to the toner held at 50 ° C. for 5 hours, and the minimum load at which the toner collapsed was examined.

The test results are summarized in Table 1. Comparative Example 1 showed an offset at 220 ° C., but Examples 1 to 4
Is an offset temperature of 220 ° C. or higher, and the fixing temperature and blocking also show preferable values. Next, examples in which the low-molecular weight substance is polystyrene, and after this is polymerized by a suspension polymerization method and then a vinyl monomer is added to perform polymerization to form styrene-based copolymers, are described in Examples 5 to 9 below. Shown in. In addition, the MW of the low molecular weight substance obtained by suspension polymerization in each example was about 10,000.

Example 5 3 L of 30 g of calcium phosphate and 1,000 g of deionized water
The mixture was placed in a 4-necked flask and the contents of the flask were replaced with nitrogen while stirring. When the temperature was further controlled to 93 ° C, 23.3 g of benzoyl peroxide (purity 75%) was added to styrene 250
It was dissolved in g and added to the flask over 30 minutes, and the polymerization was continued for 3 hours. Next, when the flask was cooled to 78 ° C., 116.7 g of styrene, 50 g of n-butyl acrylate, 0.167 g of 1,6-hexanediol diacrylate, and benzoyl peroxide (purity 75%) 0.3.
34 g was mixed and dissolved and added dropwise over 30 minutes. After the dropping was completed, the polymerization was continued for another 5 hours. After the obtained copolymer was purified and dried, its physical properties were measured. MN is 10,50
0, MW 120,000, MZ 1.22 million, MZ / MN 11
6, MFI 0.85g / 10min, Tg 74 ° C,
A styrene-based copolymer having a Ts of 142 ° C. was obtained.

Example 6 Polymerization was carried out in the same manner as in Example 5 except that 100 g of styrene and 66.7 g of n-butyl acrylate were used in the polymerization at 78 ° C., and MN was 9,600 and MW was 11.
10,000, MZ 1.05 million, MZ / MN 109, MFI 2.0g / 10min, Tg 64 ° C, Ts 151 ° C
A styrene-based copolymer of was obtained.

Example 7 Polymerization was carried out in the same manner as in Example 5 except that 83.35 g of styrene and 83.35 g of n-butyl acrylate were used in the polymerization at 78 ° C., and MN was 9,600 and MW was 110,000. , MZ 930,000, MZ / MN 97, MFI 0.26g / 10min, Tg 60 ° C, Ts 163
A styrene-based copolymer having a temperature of ℃ was obtained.

Example 8 Polymerization was carried out in the same manner as in Example 5 except that styrene was 64.26 g and n-butyl acrylate was 42.84 g in polymerization at 78 ° C., and MN was 8,200 and MW was 80,000. , MZ 720,000, MZ / MN 88, MFI 3.
A styrene-based copolymer having 2 g / 10 min, Tg of 73 ° C. and Ts of 139 ° C. was obtained.

Example 9 Polymerization was carried out in the same manner as in Example 5 except that 150 g of styrene and 100 g of n-butyl acrylate were used in the polymerization at 78 ° C., and MN was 6,500 and MW was 8.6.
MZ 780,000, MZ / MN 120, MFI 0.
A styrene-based copolymer having 35 g / 10 min, Tg of 66 ° C. and Ts of 163 ° C. was obtained.

Comparative Example 2 Polymerization at 78 ° C. of Example 7 was carried out first, and then polymerization at 93 ° C. was attempted to be carried out. However, precipitation at 78 ° C. occurred and the polymerization could not be continued until the end. There wasn't. The styrene-based copolymer for toner obtained as described above was used as a toner in the same manner as in Example 1. Further, using this toner, a fixing test was conducted at a speed of 400 mm / sec.
A blocking test was also performed. Table 2 shows the results.

Example 10 3 L of 30 g of calcium phosphate and 1,000 g of deionized water
The mixture was placed in a 4-necked flask and the contents of the flask were replaced with nitrogen while stirring. When the temperature was further controlled to 94 ° C, 23.3 g of benzoyl peroxide (purity 75%) was added to styrene 21
7.5 g, dissolved in 32.5 g of n-butyl acrylate, added into the flask over 60 minutes and continued polymerization for 5 hours,
A low molecular weight product (MW about 10,000) was obtained. Then, when the flask was cooled to 73 ° C., 103.6 g of styrene,
31.0 g of n-butyl acrylate, 0.135 g of 1,6-hexanediol diacrylate, 0.269 g of benzoyl peroxide (purity 75%), 1,1-bis (ter
t-butylperoxy) -3,3,5-trimethylcyclohexane (10-hour half-life temperature 90 ° C.) 0.538 g
Were mixed, dissolved and added dropwise over 60 minutes. After the dropping was completed, the polymerization was continued for 7 hours. Furthermore, after raising the polymerization temperature to 94 ° C., polymerization (post-polymerization) was carried out for 4 hours. After the obtained copolymer was purified and dried, its physical properties were measured. MN is 9,
200, MW 105,000, MZ 760,000, MZ / MN
83, MFI 1.8g / 10min, Tg 67
A styrene-based copolymer having a temperature of 143 ° C and a Ts of 143 ° C was obtained.

Example 11 3 L of 30 g of calcium phosphate and 1,000 g of deionized water
The mixture was placed in a 4-necked flask and the contents of the flask were replaced with nitrogen while stirring. When the temperature was further controlled to 94 ° C, 23.3 g of benzoyl peroxide (purity 75%) was added to styrene 21
7.5 g, dissolved in 32.5 g of n-butyl acrylate, added into the flask over 60 minutes and continued polymerization for 5 hours,
A low molecular weight product (MW about 10,000) was obtained. Then, when the flask was cooled to 78 ° C, 103.6 g of styrene,
31.0 g of n-butyl acrylate, 0.135 g of 1,6-hexanediol diacrylate, 0.269 g of benzoyl peroxide (purity 75%), 1,1-bis (ter
0.538 g of t-butylperoxy) -3,3,5-trimethylcyclohexane was mixed, dissolved and added dropwise over 60 minutes. After the dropping was completed, the polymerization was continued for 7 hours. Further, after the polymerization temperature was raised to 94 ° C., the polymerization was carried out for 4 hours.
After the obtained copolymer was purified and dried, its physical properties were measured. MN 8,100, MW 116,000, MZ 83
10,000, MZ / MN is 103, MFI is 2.7g / 10mi
A styrene-based copolymer having n, Tg of 70 ° C. and Ts of 141 ° C. was obtained.

Example 12 3 L of 30 g of calcium phosphate and 1,000 g of deionized water
The mixture was placed in a 4-necked flask and the contents of the flask were replaced with nitrogen while stirring. When the temperature was further controlled to 94 ° C, 23.3 g of benzoyl peroxide (purity 75%) was added to styrene 21
7.5 g, dissolved in 32.5 g of n-butyl acrylate, added into the flask over 60 minutes and continued polymerization for 5 hours,
A low molecular weight product (MW about 10,000) was obtained. Then, when the flask was cooled to 83 ° C., 103.6 g of styrene,
31.0 g of n-butyl acrylate, 0.135 g of 1,6-hexanediol diacrylate, 0.269 g of benzoyl peroxide (purity 75%), 1,1-bis (ter
0.538 g of t-butylperoxy) -3,3,5-trimethylcyclohexane was mixed, dissolved and added dropwise over 60 minutes. After the dropping was completed, the polymerization was continued for 7 hours. Further, after the polymerization temperature was raised to 94 ° C., the polymerization was carried out for 4 hours.
After the obtained copolymer was purified and dried, its physical properties were measured. 8400 MN, 138,000 MW, 10 MZ
90,000, MZ / MN 129, MFI 10g / 10mi
A styrene-based copolymer having n, Tg of 66 ° C. and Ts of 137 ° C. was obtained.

Example 13 3 L of 30 g of calcium phosphate and 1,000 g of deionized water
The mixture was placed in a 4-necked flask and the contents of the flask were replaced with nitrogen while stirring. When the temperature was further controlled to 94 ° C, 23.3 g of benzoyl peroxide (purity 75%) was added to styrene 21
7.5 g, dissolved in 32.5 g of n-butyl acrylate, added into the flask over 60 minutes, and continued polymerization for 6 hours,
A low molecular weight product (MW about 10,000) was obtained. Then, when the flask was cooled to 78 ° C, 103.6 g of styrene,
31.0 g of n-butyl acrylate, 0.135 g of 1,6-hexanediol diacrylate, 0.269 g of benzoyl peroxide (purity 75%), 1,1-bis (ter
0.538 g of t-butylperoxy) -3,3,5-trimethylcyclohexane was mixed, dissolved and added dropwise over 60 minutes. After the dropping was completed, the polymerization was continued for 7 hours. Further, after the polymerization temperature was raised to 94 ° C., the polymerization was carried out for 4 hours.
After the obtained copolymer was purified and dried, its physical properties were measured. MN 9,300, MW 111,000, MZ 76
10,000, MZ / MN is 82, MFI is 2.3g / 10mi
A styrene-based copolymer having n, Tg of 64 ° C. and Ts of 144 ° C. was obtained.

Comparative Example 3 3 L of 30 g of calcium phosphate and 1,000 g of deionized water
The mixture was placed in a 4-necked flask and the contents of the flask were replaced with nitrogen while stirring. When the temperature was further controlled to 94 ° C, 23.3 g of benzoyl peroxide (purity 75%) was added to styrene 21
7.5 g, dissolved in 32.5 g of n-butyl acrylate, added into the flask over 60 minutes, and continued polymerization for 4 hours,
A low molecular weight product (MW about 10,000) was obtained. Then, when the flask was cooled to 78 ° C, 103.6 g of styrene,
31.0 g of n-butyl acrylate, 0.135 g of 1,6-hexanediol diacrylate, 0.269 g of benzoyl peroxide (purity 75%), 1,1-bis (ter
0.538 g of t-butylperoxy) -3,3,5-trimethylcyclohexane was mixed, dissolved and added dropwise over 60 minutes. After the dropping was completed, the polymerization was continued for 7 hours. Further, after the polymerization temperature was raised to 94 ° C., the polymerization was carried out for 4 hours.
After the obtained copolymer was purified and dried, its physical properties were measured. MN is 7,900, MW is 97,000, MZ is 70
10,000, MZ / MN is 89, MFI is 20g / 10min,
A styrene-based copolymer having a Tg of 66 ° C. and a Ts of 139 ° C. was obtained.

The styrene-based copolymers obtained in Examples 10 to 13 and Comparative Example 3 were made into toner, and a copying test was conducted. Toner scattering was visually observed in the copying machine after printing 5,000 sheets. Except for Comparative Example 3, the amount of scattering was small. The results are shown in Table 3. Description of abbreviations (Tables 1 to 3) ST: Styrene BA: n-Butyl acrylate 1,6-HDA: 1,6-hexanediol diacrylate BPO: Benzoyl peroxide (purity 100% conversion) BCP: 2,2-bis (4,4'-Di-tert-butylperoxycyclohexyl) propane BTMC: 1,1-bis (tert-butylperoxy) -3,3,5-trimethylcyclohexane

[0047]

[Table 4]

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[Table 5]

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[Table 6]

[0050]

EFFECT OF THE INVENTION By using the method for producing a styrene-based copolymer for toner of the present invention, a toner excellent in high temperature offset property and low temperature fixing property can be obtained.

Claims (5)

[Claims] 1. A weight average molecular weight of 5,000 to 20,000.
Toner characterized by suspension polymerization by adding a vinyl-based monomer mixture containing a vinyl-based monomer having two or more non-conjugated double bonds to a dispersion liquid in which a styrene-based polymer of No. 0 is dispersed. For producing styrene-based copolymer for automobile. 2. Non-conjugated 2 in vinyl-based monomer mixture
The method for producing a styrene-based copolymer for toner according to claim 1, wherein the content of the vinyl-based monomer having two or more heavy bonds is 0.01 to 0.3% by weight. 3. The method for producing a styrene-based copolymer for a toner according to claim 1, wherein the styrene-based polymer is produced by a suspension polymerization method. 4. The production of a styrene copolymer for a toner according to claim 1, wherein the weight ratio of the styrene polymer and the vinyl monomer mixture is 80:20 to 50:50. Method. 5. A method for producing a toner comprising melt-kneading a styrene-based copolymer for a toner and a colorant obtained by the production method according to claim 1 and then cooling, pulverizing and classifying. Method.