JPH07120971A - Toner binder resin and its production - Google Patents

Abstract

PURPOSE:To provide a toner binder resin with which an excellent toner having superior fixation properties, anti-offset properties and blocking resistance and also no odor can be obtained by reducing the residual monomer content of the binder resin to a specified value or less through producing the binder resin by the suspension polymerization at a high reaction temp. CONSTITUTION:This binder resin is a styrene-acrylic copolymer which is produced by subjecting a polymerizable monomer composition consisting essentially of a styrenic monomer and a (meth)acrylic monomer to suspension polymerization at a >=100 deg.C reaction temp. and has a <=100ppm residual monomer content. More specifically, the styrene-acrylic copolymer having a <=100ppm residual monomer content is produced by adding 1 to 9wt.% of a peroxide polymerization initiator having a 60 to 90 deg.C ten hour half-life temp. and 1 to 4wt.% of another peroxide polymerization initiator having a 95 to 110 deg.C ten hour half-life temp. to a polymerizable monomer composition consisting essentially of a styrenic monomer and a (meth)acrylic monomer and then subjecting the monomer composition to suspension polymerization at a >=100 deg.C reaction temp.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a binder resin for toner used for developing an electrostatic charge image or a magnetic latent image in an electrophotographic method, an electrostatic recording method, an electrostatic printing method and the like, and a method for producing the same. Yes, more specifically, fixability,
The present invention relates to a binder resin for a toner which is excellent in non-offset property and blocking resistance and can provide a toner having less odor, and a method for producing the same.

[0002]

2. Description of the Related Art In copying machines, printers, facsimiles and the like used in electrophotography, electrostatic recording, electrostatic printing, etc., toner is usually heated by using a heating roller heated to a temperature of about 100 to 230.degree. Is fixed on paper. In such a fixing process, a large number of sheets of paper are often fixed in succession, and a small amount of toner is accumulated on the heating roller to such an extent that the non-offset property is not affected. And
The temperature of the heating roller increases due to continuous rotation and continuous supply of paper, etc., and the toner accumulated on the heating roller is heated, and the residual monomer and residual solvent remaining in the toner are volatilized, It produces an odor. Such an odor problem is caused by residual monomers and residual solvent contained in the binder resin for toner, and reduction of the residual monomers and residual solvent of the binder resin has been demanded.

In order to meet such demands, for example, as described in JP-A-1-70765, heating is carried out at a temperature not lower than the glass transition temperature of a resin obtained after polymerization to give a predetermined amount of water. A method of reducing residual monomers by distilling off is proposed.

[0004]

However, recently, there has been a demand for a high-speed copying machine or a printer capable of high-speed printing, and a binder resin for toner which has an excellent fixing property is required. Nowadays, a method of polymerizing a monomer at a high reaction temperature to lower the molecular weight of the binder resin to improve the fixing property is being carried out. As described above, when the monomer is polymerized at a high reaction temperature, the polymerization initiator tends to disappear quickly and the residual amount of the monomer tends to increase. In the case of containing a large amount of the residual monomer, JP-A-1-70765 and the like are disclosed. However, it was not possible to sufficiently reduce the residual monomer even by performing the method described in (1).

An object of the present invention is to provide a binder resin for a toner, which has excellent fixability and can be used in high-speed copying machines, printers, etc., and which can obtain a toner having a low residual monomer amount and a low odor, and a method for producing the same. To provide a method.

[0006]

That is, the binder resin for toner of the present invention is a suspension polymerization of a polymerizable monomer component containing a styrene monomer and a (meth) acrylic monomer as main components at a reaction temperature of 100 ° C. or higher. And a residual monomer content of 100 ppm or less. Further, the method for producing a binder resin for a toner according to the present invention comprises adding a polymerizable monomer component containing a styrene-based monomer and a (meth) acrylic-based monomer as main components to 10
1 to 9% by weight of a peroxide-based polymerization initiator having a time half-life temperature of 60 to 90 ° C. and a 10 hour half-life temperature of 95 to 11
Add 1 to 4% by weight of a peroxide-based polymerization initiator at 0 ° C.,
A styrene-acrylic copolymer having a residual monomer content of 100 ppm or less is obtained by carrying out suspension polymerization at a reaction temperature of 100 ° C. or higher.

The polymerizable monomer component used in the binder resin for toner of the present invention is mainly composed of a styrene-based monomer and a (meth) acrylic-based monomer, and the amount used is the styrene-acrylic-based copolymer weight obtained. The glass transition temperature of the coalescence can be appropriately set so as to be in the range of 50 to 70 ° C., but from the viewpoint of the moisture resistance of the toner, the styrene-based monomer is contained in an amount of 50% by weight in all the monomer components.
It is preferably used in the above range.

Examples of the styrene type monomer include styrene, o-methylstyrene, m-methylstyrene and p.
-Methylstyrene, p-methoxystyrene, p-phenylstyrene, p-chlorostyrene, 3,4-dichlorostyrene, p-ethylstyrene, 2,4 dimethylstyrene, pn-butylstyrene, p-tertbutylstyrene. , Pn-hexylstyrene, pn-octylstyrene, pn-nonylstyrene, pn-decylstyrene, pn-dodecylstyrene, α-methylstyrene and the like, and these may be used alone or in combination of two or more. Can be used in combination. Among them, styrene, p-methylstyrene and α-methylstyrene are preferable, and styrene is particularly preferable. By using such a styrene-based monomer, the moisture resistance of the toner can be improved.

The (meth) acrylic monomers (acrylic monomers or methacrylic monomers) include acrylic acid and methacrylic acid; ethyl acrylate, methyl acrylate, n-butyl acrylate, isobutyl acrylate, propyl acrylate. Acrylic acid esters such as 2-ethylhexyl acrylate, stearyl acrylate, lauryl acrylate, 2-ethoxyethyl acrylate, 2-methoxyethyl acrylate, 2-budoxyethyl acrylate; ethyl methacrylate, methyl methacrylate, methacrylic acid n-butyl, isobutyl methacrylate, propyl methacrylate, 2-ethylhexyl methacrylate, stearyl methacrylate, lauryl methacrylate, glycidyl methacrylate, cyclohexyl methacrylate, methacrylic acid Methacrylic acid esters such as ethylaminoethyl, dimethylaminoethyl methacrylate, 2-ethoxyethyl methacrylate, 2-methoxyethyl methacrylate, 2-budoxyethyl methacrylate and the like can be mentioned, and these can be used alone or in combination of two or more kinds. be able to. Among them, methacrylic acid, methyl methacrylate and n-butyl methacrylate are preferable.

Further, in the present invention, a bifunctional or higher functional vinyl-based monomer, that is, a reactive vinyl-based monomer having two or more reactive double bonds in one molecule can be used, if necessary. Examples of the bifunctional or higher functional vinyl monomer include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene, ethylene glycol di (meth) acrylate, triethylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate, Polyethylene glycol di (meth) acrylate, dipropylene glycol di (meth)
Acrylate, 1,3-butylene glycol di (meth)
Examples thereof include acrylates and bisphenol A derivative-based di (meth) acrylates, which can be used alone or in combination of two or more. Of these, divinylbenzene and 1,3-butylene glycol dimethacrylate are preferable. These bifunctional or higher vinyl monomers are preferably used in an amount of 0.3 to 5% by weight, more preferably 0.4 to 4.
It is in the range of 5% by weight. This is because if it is less than 0.3% by weight, the cross-linking structure of the binder resin is insufficient and the non-offset property of the toner tends to be poor. This is because there is a tendency to be damaged.

The binder resin for a toner of the present invention can be obtained by suspension polymerization of a polymerizable monomer component containing the above-mentioned styrene monomer and (meth) acrylic monomer as main components at a reaction temperature of 100 ° C. or higher. is important.

Binder resins composed of styrene-acrylic copolymers are generally prepared by suspension polymerization, solution polymerization,
It can be obtained by a polymerization method such as an emulsion polymerization method or a bulk polymerization method. However, in the solution polymerization method, it is difficult to remove the solvent used, and the residual solvent causes problems such as odor and image stability. In addition, the emulsion polymerization method has a problem that the emulsifier used remains in the binder resin and thus has poor moisture resistance. Further, the bulk polymerization method is difficult to control heat generation and is extremely inferior in productivity. On the other hand, the suspension polymerization method does not have the problem of odor due to the residual solvent because it does not use a solvent, and it is easy to control the heat generation, and the amount of the dispersant used is small and the moisture resistance is not impaired. Therefore, as the binder resin for low odor toner, the one polymerized by the suspension polymerization method is most suitable. Further, by carrying out suspension polymerization at a reaction temperature of 100 ° C. or higher, the molecular weight of the binder resin can be reduced, the fixing property of the toner can be improved, and the polymerization initiator is efficiently consumed to reduce the residual monomer. Is possible, preferably 110-1
It is in the range of 45 ° C.

The binder resin for toner of the present invention must have a residual monomer content of 100 ppm or less. This is because the residual monomer content is 100
This is because if it exceeds ppm, the odor of the toner cannot be suppressed sufficiently, and the range is preferably 80 ppm or less. Further, in the present invention, the binder resin for toner has a softening temperature of 110 to 190 ° C., a glass transition temperature of 50 to 70 ° C., a gel fraction of 2 to 65% by weight, and a solvent permeation gel permeation chromatography. It is preferable that the maximum peak molecular weight in the molecular weight distribution is 35,000 or less and the acid value is 10 mgKOH / g or less.

This is because if the softening temperature is lower than 110 ° C., the toner non-offset property tends to be poor, and if it exceeds 190 ° C., the toner fixing property tends to be poor.
More preferably, it is in the range of 115 to 185 ° C. Further, if the glass transition temperature is lower than 50 ° C., the blocking resistance of the toner tends to be poor, and if it exceeds 70 ° C., the fixing property of the toner tends to be poor, preferably 5
It is in the range of 2 to 68 ° C. This is because if the gel fraction is less than 2% by weight, the non-offset property of the toner tends to be poor, and if it exceeds 65% by weight, the fixability of the toner tends to be poor, preferably in the range of 8 to 60% by weight. Is. This is because if the maximum peak molecular weight in the molecular weight distribution by gel permeation chromatography of the solvent-soluble component exceeds 35,000, the fixability of the toner tends to be poor.
The range is preferably 33000 or less. Further, when the acid value exceeds 10 mgKOH / g, the moisture resistance of the toner tends to deteriorate, and the range is preferably 8 mgKOH / g or less.

The binder resin for a toner of the present invention comprises a polymerizable monomer component containing the above-mentioned styrene-based monomer, (meth) acrylic-based monomer and optionally a bi- or higher functional vinyl-based monomer at a reaction temperature of 100 ° C. or higher. 2 to
It is produced by carrying out suspension polymerization under a pressure of about 4 Kg / cm ² . In the present invention, the polymerization initiator used for suspension polymerization has a 10-hour half-life temperature of 60 to 9
A peroxide-based polymerization initiator having a temperature of 0 ° C., preferably 60 to 80 ° C. and a 10-hour half-life temperature of 95 to 110 ° C., preferably 96 to 107 ° C. is used in combination.
This is because by using a peroxide-based polymerization initiator having a 10-hour half-life temperature of 60 to 90 ° C., the molecular weight of the solvent-soluble component of the binder resin can be reduced and the content of the remaining monomer can be reduced. This is because it is possible to reduce The 10-hour half-life temperature is 95 to 1
This is because the amount of residual monomer in the binder resin can be reduced by using the peroxide-based polymerization initiator at 10 ° C.

As the peroxide type polymerization initiator having a 10-hour half-life temperature of 60 to 90 ° C., for example, lauryl peroxide (10-hour half-life temperature = 62 ° C.), coumerperoxy octoate (68 ° C.) , Benzoyl peroxide (74 ° C), t-butylperoxy (2-ethylhexanoate) (72.5 ° C), m-toluoyl peroxide (73 ° C), t-butylperoxyisobutyrate (78). C.), 1,1-bis (t-butylperoxy)
3,3,5-trimethylcyclohexane (90 ° C.) and the like can be mentioned, and these can be used alone or in combination of two or more kinds. Among them, benzoyl peroxide is preferable. These polymerization initiators are used in the range of 1 to 9% by weight based on the total amount of styrene-based monomers and (meth) acrylic-based monomers, preferably 1.5 to
It is in the range of 8.5% by weight. This is because if the amount is less than 1% by weight, the residual monomer cannot be sufficiently reduced, and if it exceeds 9% by weight, decomposition byproducts such as benzoic acid increase.

As the peroxide type polymerization initiator having a 10-hour half-life temperature of 95 to 110 ° C., for example, t-butylperoxylaurate (10-hour half-life temperature = 96 ° C.), cyclohexanone peroxide (97 ° C.) ), T-butyl peroxyisopropyl carbonate (98 ° C.), t-
Butyl peroxyacetate (102 ° C.), t-bityl peroxybenzoate (104 ° C.), di-t-butyl peroxyisophthalate (107 ° C.) and the like,
These may be used alone or in combination of two or more. Of these, t-butyl peroxybenzoate is preferable. These polymerization initiators are used in the range of 1 to 4% by weight, preferably 1 to 3% by weight, based on the total amount of styrene-based monomers and (meth) acrylic-based monomers.
Is the range. This is because if the amount is less than 1% by weight, the residual monomer cannot be sufficiently reduced.
This is because the decomposition by-products increase when it exceeds.

As the dispersant used in the present invention, polyvinyl alcohol usually used in suspension polymerization,
Examples thereof include sodium polyacrylate, polyether dispersants, ethylene oxide dispersants and the like. Further, as a dispersion aid, sodium sulfate, sodium carbonate, calcium carbonate, manganese sulfate, hydrogen peroxide solution, boric acid or the like can be used in combination. The amount of deionized water used in the suspension polymerization is 1.5 to a weight ratio with respect to the polymerizable monomer component in order to alleviate the heat generation during the polymerization and make the reaction stable.
The range of 2.5 is preferable, and the range of 1.8 to 2.3 is more preferable.

In the present invention, the suspension polymerization is carried out at a reaction temperature of 100 ° C. or higher, but the temperature rising time from room temperature to the reaction temperature is preferably about 20 to 90 minutes. This is because if it is less than 20 minutes, it tends to be difficult to obtain a crosslinked structure of the binder resin, and if it exceeds 90 minutes, the effect of lowering the molecular weight of the binder resin tends to be reduced.

Further, in the present invention, for the purpose of reducing benzoic acid, which is a by-product of decomposition of the polymerization initiator, and improving the charge stability of the toner, the suspension polymerization is carried out at 85 ° C.
It is also possible to perform alkali treatment at the above temperature. If the alkali treatment temperature is lower than 85 ° C, the effect of reducing benzoic acid and the like is not sufficient, and the temperature is preferably 88 ° C or higher. Examples of the alkali used include hydroxides of alkali metals such as lithium, sodium, potassium and rubidium, and sodium hydroxide is preferable. The amount of these alkalis used is styrene monomer and (meth)
It is preferably in the range of 0.1 to 2% by weight, more preferably 0.3 to
It is in the range of 1.5% by weight.

Further, in the present invention, after the suspension polymerization is carried out, the residual monomer can be further reduced by carrying out the distillation in which the deionized water and the residual monomer are caused to flow out from the reaction system. . When the distillation step and the alkali treatment are used in combination, it is preferable to carry out the distillation before or at the same time as the alkali treatment. Distillation is preferably carried out at a temperature of 100 ° C. or higher, which is the boiling point of deionized water, and it is preferable to let out an amount of 5 to 35% by weight of the amount of deionized water used for suspension polymerization, more preferably 10 to It is in the range of 30% by weight.

In the present invention, the glass transition temperature was determined by the DSC method (heating rate 10 ° C./min) after the sample was heated to 100 ° C. and melt-quenched. As for the softening temperature, a flow tester (CFT-500 manufactured by Shimadzu Corp.) having a nozzle of 1 mmφ × 10 mm was used, and when half of the sample amount flowed out under the conditions of a load of 30 Kgf and a heating rate of 3 ° C./min. Indicated by the temperature.
The acid value was determined using a titration method with KOH.

The molecular weight was determined by gel permeation chromatography (HCL-8020 manufactured by Toso Co., Ltd.) in terms of polystyrene. Specifically, regarding the measuring method in the molecular weight measurement, the calculation of the molecular weight and the molecular weight distribution were obtained from the relationship between the calibration curve prepared by several kinds of monodisperse polyethylene standard samples and the counted values. At this time, the polyethylene standard sample has a molecular weight of 6 × 10.
² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75 × 10 ⁴ ,
5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 10 ⁵ ,
Examples include those of 8.6 × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ , and it is preferable to select and use 10 or more. In addition, columns TSKgel, G1000H, G20
00H, G2500H, G3000H, G4000H,
G5000H, G6000H, G7000H, GMH and the like can be mentioned, and it is preferable to use them in combination.

The gel fraction was measured by placing 0.5 g of the sample in 50 ml of tetrahydrofuran (THF), heating and dissolving at 60 ° C. for 3 hours, filtering through a glass filter covered with Celite # 545, and using a vacuum dryer at 80 ° C. The weight when fully dried was divided by the initial weight.

[0025]

EXAMPLES The present invention will be specifically described below with reference to examples. In the embodiment, the fixing property is 200% by using a copying machine capable of freely changing the fixing temperature.
mm5 / min, initial density (ID) 0.95-1.0
5, the temperature at which the ratio of the density after rubbing with a sand eraser and the initial density exceeds 85% was determined as the fixing temperature, and evaluated according to the following criteria. ⊚: Less than 185 ° C. ∘: 186 to 195 ° C. ×> 195 ° C. or more The non-offset property is set to 200 mm / min by using a copying machine that can freely change the temperature, and the non-offset property is 2 The temperature at which the double transcription was expressed was evaluated according to the following criteria. ⊚: 220 ° C. or higher ○: 210 to less than 220 ° C. ×: less than 210 ° C.

For blocking resistance, about 5 g of toner is weighed in a sample bottle and placed in a hot air dryer kept at about 50 ° C.
After standing for 2 hours, the aggregation state of the toner when the taken out sample bottle was turned upside down was evaluated according to the following criteria. ⊚: The toner is uniformly dispersed by tapping once: O: The toner is uniformly dispersed by tapping three times ×: The toner is not aggregated and dispersed Odor is detected by using a copying machine whose temperature can be freely changed. The odor around the heating roller after copying a plurality of sheets at the fixing temperature at a fixing speed of 200 mm / min was evaluated according to the following criteria.

⊚: Almost no odor ○: Slight odor but no problem X: Odor was not practically preferable.

Examples 1-3 220 parts by weight of deionized water, 0.2 polyvinyl alcohol
One part by weight and 0.03 part by weight of hydrogen peroxide solution were mixed and charged into a reaction vessel equipped with a distillation column and a stirrer. Next, each component of the polymerizable monomer as shown in Table 1 was added,
It mixed and put into the reaction container. Furthermore, the stirring speed is set to 20.
After the polymerization initiator shown in Table 1 was charged at 0 rpm, the reaction vessel was closed. Then, the temperature rise in the reaction system is started, and the temperature in the reaction system is reduced to 130 in about 45 minutes after the temperature rise is started.
Suspension polymerization was initiated at ℃ and pressure of 3.5 kg / cm ² . Approximately 4 hours after the suspension polymerization was started, the temperature in the reaction system was lowered to 90 ° C., the pressure in the reaction vessel was set to normal pressure, and the stirring speed was set to 300 rpm. Then, the temperature in the reaction system was raised to 100 ° C. and the distillation step was performed. A mixed liquid of deionized water and the remaining monomer was allowed to flow out from the reaction system at the flow rate shown in Table 1. Further, while maintaining the temperature in the reaction system at about 90 ° C., 0.5 part by weight of sodium hydroxide was added and alkali treatment was performed for about 30 minutes. Then, the temperature in the reaction system was cooled to room temperature and the resulting resin was taken out,
After thoroughly washing with deionized water, the deionized water was thoroughly dehydrated and dried at 50 ° C. for about 24 hours to obtain a binder resin. The obtained resin had a glass transition temperature (Tg), a softening temperature, an acid value, a gel fraction, a molecular weight distribution and a residual monomer amount as shown in Table 2.

Further, 91 parts by weight of the obtained binder resin, 5 parts by weight of carbon black, 1 part by weight of the charge control agent and 3 parts by weight of polypropylene wax were mixed, and the resin temperature during kneading was softened by using an internal mixer. The mixture was kneaded for 30 minutes at a temperature 20 ° C higher than the temperature. Then, fine pulverization and classification are performed to obtain a particle size of 5 to 20 μm.
Toner was obtained. Using the obtained toner, the fixability, non-offset property, blocking resistance and odor were evaluated, and the results are shown in Table 2.

Example 4 220 parts by weight of deionized water, polyvinyl alcohol 0.2
One part by weight and 0.03 part by weight of hydrogen peroxide solution were mixed and charged into a reaction vessel equipped with a distillation column and a stirrer. Next, each component of the polymerizable monomer as shown in Table 1 was added,
It mixed and put into the reaction container. Furthermore, the stirring speed is set to 20.
After the polymerization initiator shown in Table 1 was charged at 0 rpm, the reaction vessel was closed. Then, the temperature rise in the reaction system is started, and the temperature in the reaction system is reduced to 130 in about 45 minutes after the temperature rise is started.
Suspension polymerization was initiated at ℃ and pressure of 3.5 kg / cm ² . Approximately 4 hours after the suspension polymerization was started, the temperature in the reaction system was lowered to 90 ° C., the pressure in the reaction vessel was set to normal pressure, and the stirring speed was set to 300 rpm. Then, the temperature in the reaction system was maintained at about 90 ° C., 0.5 part by weight of sodium hydroxide was added, and alkali treatment was performed for about 30 minutes. Then
The temperature in the reaction system was cooled to room temperature, the resulting resin was taken out, thoroughly washed with deionized water, dehydrated sufficiently with deionized water, and dried at 50 ° C. for about 24 hours. A binder resin was obtained. The obtained resin has a glass transition temperature (Tg), a softening temperature, an acid value,
It was the gel fraction, the molecular weight distribution and the amount of residual monomer.
Further, using the obtained binder resin, Example 1
Toner was obtained in the same manner as in (1). Using the obtained toner, the fixability, non-offset property, blocking resistance and odor were evaluated, and the results are shown in Table 2.

Examples 5-7 220 parts by weight of deionized water, polyvinyl alcohol 0.2
One part by weight and 0.03 part by weight of hydrogen peroxide solution were mixed and charged into a reaction vessel equipped with a distillation column and a stirrer. Next, each component of the polymerizable monomer as shown in Table 1 was added,
It mixed and put into the reaction container. Furthermore, the stirring speed is set to 20.
After the polymerization initiator shown in Table 1 was charged at 0 rpm, the reaction vessel was closed. Then, the temperature rise in the reaction system is started, and the temperature in the reaction system is reduced to 130 in about 45 minutes after the temperature rise is started.
Suspension polymerization was initiated at ℃ and pressure of 3.5 kg / cm ² . About 5 hours after the suspension polymerization was started, the temperature in the reaction system was lowered to 90 ° C., the pressure in the reaction vessel was set to normal pressure, and the stirring speed was set to 300 rpm. Then, the temperature in the reaction system was raised to 100 ° C. and the distillation step was performed. 44 parts by weight of a mixed liquid of deionized water and the remaining monomer was flowed out from the reaction system. Further, while maintaining the temperature in the reaction system at about 90 ° C., 0.5 part by weight of sodium hydroxide was added and alkali treatment was performed for about 30 minutes. Then, the temperature in the reaction system was cooled to room temperature, the resulting resin was taken out, thoroughly washed with deionized water, then the deionized water was thoroughly dehydrated and dried at 50 ° C. for about 24 hours. Then, a binder resin was obtained. The obtained resin had a glass transition temperature (Tg), a softening temperature, an acid value, a gel fraction, a molecular weight distribution and a residual monomer amount as shown in Table 2. Further, a toner was obtained by using the obtained binder resin in the same manner as in Example 1. Using the obtained toner, the fixing property, non-offset property, blocking resistance and odor are evaluated,
The results are shown in Table 2.

Comparative Examples 1-2 220 parts by weight of deionized water, polyvinyl alcohol 0.2
One part by weight and 0.03 part by weight of hydrogen peroxide solution were mixed and charged into a reaction vessel equipped with a distillation column and a stirrer. Next, each component of the polymerizable monomer as shown in Table 1 was added,
It mixed and put into the reaction container. Furthermore, the stirring speed is set to 20.
After the polymerization initiator shown in Table 1 was charged at 0 rpm, the reaction vessel was closed. Then, the temperature rise in the reaction system is started, and the temperature in the reaction system is reduced to 130 in about 45 minutes after the temperature rise is started.
Suspension polymerization was initiated at ℃ and pressure of 3.5 kg / cm ² . About 5 hours after the suspension polymerization was started, the temperature in the reaction system was lowered to 90 ° C., the pressure in the reaction vessel was set to normal pressure, and the stirring speed was set to 300 rpm. Then, the temperature in the reaction system was raised to 100 ° C. and the distillation step was performed. 44 parts by weight of a mixed liquid of deionized water and the remaining monomer was flowed out from the reaction system. Further, while maintaining the temperature in the reaction system at about 90 ° C., 0.5 part by weight of sodium hydroxide was added and alkali treatment was performed for about 30 minutes. Then, the temperature in the reaction system was cooled to room temperature, the resulting resin was taken out, thoroughly washed with deionized water, then the deionized water was thoroughly dehydrated and dried at 50 ° C. for about 24 hours. Then, a binder resin was obtained. The obtained resin had a glass transition temperature (Tg), a softening temperature, an acid value, a gel fraction, a molecular weight distribution and a residual monomer amount as shown in Table 2. Further, a toner was obtained by using the obtained binder resin in the same manner as in Example 1. Using the obtained toner, the fixing property, non-offset property, blocking resistance and odor are evaluated,
The results are shown in Table 2.

Comparative Example 3 220 parts by weight of deionized water, polyvinyl alcohol 0.2
One part by weight and 0.03 part by weight of hydrogen peroxide solution were mixed and charged into a reaction vessel equipped with a distillation column and a stirrer. Next, each component of the polymerizable monomer as shown in Table 1 was added,
It mixed and put into the reaction container. Furthermore, the stirring speed is set to 20.
After the polymerization initiator shown in Table 1 was charged at 0 rpm, the reaction vessel was closed. Next, the temperature rise of the reaction system is started, and the temperature in the reaction system is raised to 85 ° C. about 45 minutes after the start of the temperature rise.
As a result, suspension polymerization was started. Approximately 5 hours after the suspension polymerization was started, the pressure inside the reaction vessel was adjusted to normal pressure and the stirring speed was set to 30.
It was set to 0 rpm. Then, the temperature in the reaction system was raised to 100 ° C. and the distillation step was performed. 44 parts by weight of a mixed liquid of deionized water and the remaining monomer was flowed out from the reaction system.
Further, the temperature in the reaction system is kept at about 90 ° C., 0.5 part by weight of sodium hydroxide is added, and alkali treatment is performed at about 30 ° C.
I went for a minute. Then, the temperature in the reaction system was cooled to room temperature, the resulting resin was taken out, thoroughly washed with deionized water, then the deionized water was thoroughly dehydrated and dried at 50 ° C. for about 24 hours. Then, a binder resin was obtained. The obtained resin has a glass transition temperature (T
g), softening temperature, acid value, gel fraction, molecular weight distribution and residual monomer amount. Further, a toner was obtained by using the obtained binder resin in the same manner as in Example 1.
Using the obtained toner, the fixability, non-offset property, blocking resistance and odor were evaluated, and the results are shown in Table 2.

[0034]

[Table 1]

[0035]

[Table 2]

The symbols of monomers and polymerization initiators shown in Tables 1 and 2 represent the following compounds, respectively. St; styrene nBA; n-butyl acrylate MAA; methacrylic acid BDMA; 1,3-butylene glycol dimethacrylate BPO; benzoyl peroxide PZ; t-butyl peroxybenzoate.

As is clear from Table 2, the toners of Examples 1 to 7 using the binder resin of the present invention are excellent in fixing property, and the toners of Examples 1 to 4 and 7 are excellent.
The toners of Examples 5 and 6 were good. Regarding the non-offset property, all the toners of Examples 1 to 7 were excellent. Regarding the blocking resistance, the toners of Examples 1 to 6 were excellent, and the toner of Example 7 was good.
Regarding the odor, the toners of Examples 1 to 3 and 6 to 7 were excellent, and the toners of Examples 4 and 5 had a slight odor, but there was no problem in practical use. On the contrary,
The toner of Comparative Example 1 had an odor and was not preferable in practical use. The toner of Comparative Example 2 was excellent in odor, but was inferior in non-offset property and blocking resistance. The toner of Comparative Example 3 was inferior in fixability and odor.

[0038]

The binder resin for toner of the present invention is
It is obtained by suspension polymerization at a high reaction temperature, and by reducing the content of the residual monomer, it is possible to obtain an excellent toner having excellent fixability, non-offset property and blocking resistance, and having no odor. It is also compatible with high-speed copiers and printers.

Claims (5)

[Claims] 1. A polymerizable monomer component containing a styrene-based monomer and a (meth) acrylic-based monomer as main components is 100
A styrene-acrylic copolymer obtained by suspension polymerization at a reaction temperature of ℃ or more, the residual monomer content is 10
A binder resin for a toner, which is 0 ppm or less. 2. The binder resin for a toner according to claim 1, wherein the polymerizable monomer component contains a bifunctional or higher functional vinyl monomer. 3. A polymerizable monomer component containing a styrene monomer and a (meth) acrylic monomer as main components,
1 to 9% by weight of a peroxide-based polymerization initiator having a 10-hour half-life temperature of 60 to 90 ° C. and a 10-hour half-life temperature of 95 to
By adding 1 to 4% by weight of a peroxide type polymerization initiator at 110 ° C. and carrying out suspension polymerization at a reaction temperature of 100 ° C. or higher, the residual monomer content is 100 ppm or less of styrene-acrylic copolymerization weight. A method for producing a binder resin for a toner, which comprises obtaining a coalescence. 4. The method for producing a binder resin for a toner according to claim 3, wherein the polymerizable monomer component contains a bifunctional or higher functional vinyl monomer. 5. After the suspension polymerization, 5 to 35% by weight of deionized water and residual monomer with respect to the deionized water used for the suspension polymerization are discharged out of the reaction system. The method for producing the binder resin for toner according to claim 3.