JPH0832809B2 - Method for producing binder resin for toner - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a binder resin for a toner used in a dry developer used in electrophotography, electrostatic recording, magnetic recording, and the like.

[Conventional technology]

Conventionally, as electrophotography, many methods are known, such as U.S. Pat.No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43-24748, but generally a photoconductive substance is used. Then, an electric latent image is formed on the photoconductor by various means, the latent image is then developed with toner, and the toner image is transferred to a transfer material such as paper, if necessary, and then heated.
A copy is obtained by fixing with pressure, heat and pressure, or solvent vapor. Further, when there is a step of transferring the toner image, a step for removing the residual toner is usually provided.

A developing method for visualizing an electric latent image using toner is, for example, a magnetic brush method described in U.S. Pat.No. 2,874,063, a cascade developing method described in U.S. Pat. No. 2,618,552 and 2,221,776. And the powder cloud method described in US Pat. No. 3,909,258 and the method using a conductive magnetic toner described in US Pat. No. 3,909,258 are known.

As a toner applied to these developing methods, a fine powder in which a dye / pigment is dispersed in a natural or synthetic resin has been conventionally used. For example, particles obtained by finely pulverizing a dispersion of a colorant in a binder resin such as polystyrene to about 1 to 30 μm are used as toner. A magnetic toner containing magnetic particles such as magnetite is used. On the other hand, in the case of a system using a so-called two-component developer, the toner is usually used by being mixed with carrier particles such as glass beads and iron powder.

Nowadays, such a recording method has been widely used not only for general copying machines but also for computer output, microfilm printing, and the like. Therefore, the required performance has become higher, and various performances such as smaller size, lighter weight, lower energy, higher speed, more maintenance-free, and more personal have been demanded at the same time. It was In order to satisfy these requirements, the demands on the toner have become more severe in various aspects. For example, if the size is made smaller, the heat source such as the fixing device and the exposure lamp can be pushed into a narrow space, so that the temperature inside the device tends to increase. Therefore, the blocking property of the toner must be further improved. Further, in order to reduce the weight, the fixing roller is designed to be thinner and thinner, and the cleaning mechanism for the fixing roller and the cleaning mechanism for the photoconductor tend to be simple and lightweight.
Do not attach a coating device such as offset prevention oil to the fixing machine. Therefore, the fixing property of the toner, the offset resistance, and the cleaning resistance of the photoconductor must be improved. Further, in order to achieve lower energy consumption and higher speed, the fixing property of the toner must be naturally improved, and in order to be more personalized, it is necessary to improve the reliability and to prevent jamming. Becomes important. Jam generally occurs when the copy paper is wrapped around the roller of the fixing device, and it is necessary to improve the wrapping resistance of the toner around the fixing roller. However, as shown in FIG. 6, there are many contradictory characteristics required for toner production and various characteristics of the toner itself.

Even if the above examples are taken, the demand for toner is severe, but the demand cannot be satisfied unless these are simultaneously improved. However, in order to realize these, it is meaningless to lower the developing characteristics such as the image quality and the durability of the toner, and the toner production efficiency.

These largely depend on the performance of the binder resin of the toner. There are proposals to improve these by using a release agent, a plasticizer, and other additives, but these are auxiliary.

Various methods have been proposed for improving the binder resin.

For example, JP-A-56-158340 proposes a toner composed of a low molecular weight polymer and a high molecular weight polymer, but this binder resin is difficult to actually contain a crosslinking component. In order to improve the offset resistance with higher performance, it is necessary to increase the molecular weight or increase the ratio of the high molecular weight polymer. This direction is a direction in which the pulverizability is remarkably reduced, and it is difficult to obtain what is practically satisfactory. Further, regarding a toner blended with a low molecular weight polymer and a cross-linked polymer, JP-A-58-86558,
A toner containing a low molecular weight polymer and an insoluble and infusible high molecular weight polymer as main resin components has been proposed. According to the method, the fixing property and the pulverizing property are thought to be improved, but the weight average molecular weight / number average molecular weight (Mw / M
Since n) is as small as 3.5 or less and the insoluble and infusible high molecular weight polymer is as large as 40 to 90 wt%, it is difficult to satisfy high performance with offset resistance and grindability. It is extremely difficult to produce a toner that sufficiently satisfies the fixability, offset resistance, and pulverizability unless it is a fixing machine having a supply device for preventing liquid. Furthermore, if the insoluble and infusible high molecular weight polymer increases, the melt viscosity becomes extremely high in the heat kneading at the time of toner preparation, so that the heat kneading should be performed at a temperature much higher than usual, or the heat kneading should be performed in a high shear. As a result, the former has a problem that the toner properties are deteriorated due to the thermal decomposition of other additives, and the latter has a problem that the molecules of the binder resin are excessively cleaved and the initial offset resistance performance is difficult to be obtained.

Further, in JP-A-60-166958, a number average molecular weight of 500-15
A toner composed of a resin composition obtained by polymerization in the presence of low molecular weight poly α-methylstyrene having a molecular weight of 00 has been proposed.

Particularly, in this publication, the number average molecular weight (Mn) is 9,000 to 30,000.
However, if Mn is increased in order to further improve the offset resistance, the fixability and the pulverizability at the time of toner production become a practical problem, and therefore high performance offset resistance and pulverizability are obtained. Is difficult to satisfy. As described above, the toner having poor pulverizability at the time of toner production reduces the production efficiency at the time of toner production,
Rough toner is apt to be mixed in, which may result in skipped images, which is not preferable.

Further, in JP-A-56-16144, in the molecular weight distribution by GPC, the molecular weight is 10 ³ to 8 × 10 ⁴ and the molecular weight is 10 ⁵ to 2 × 10 ^6.
A toner containing a binder resin component having at least one local maximum value in each area has been proposed. In this case, the grindability, offset resistance, fixing property, filming and fusing to the photoconductor, image quality, etc. are excellent, but further improvement in offset resistance and fixing property in the toner is demanded. In particular, it is difficult for the resin to meet today's strict requirements while further improving the fixability and maintaining or improving various other performances.

As described above, highly satisfying items have not been proposed yet.

[Object of the Invention]

An object of the present invention is to provide a method for producing a binder resin for toner, which simultaneously satisfies excellent performances in various items.

Another object of the present invention is to provide a method for producing a binder resin for toner which has excellent fixing properties and at the same time excellent offset properties, winding properties and blocking properties.

Another object of the present invention is to provide a method for producing a binder resin for toner, which has good pulverizability and good toner production efficiency.

Another object of the present invention is to provide a method for producing a binder resin for toner, which is excellent in fusion resistance into the apparatus at the time of pulverization or fusion resistance of a photoconductor or the like.

Another object of the present invention is to provide a method for producing a binder resin for toner, which has no problem in developability, especially in image quality and durability.

[Outline of Invention]

That is, the present invention, in the molecular weight distribution by gel permeation chromatography (GPC), has a main peak in the region of molecular weight 2,000 to 10,000 and weight average molecular weight / number average molecular weight (Mw / Mn) ≤ 3.5, glass transition point ( Tg) ≧ 50 ° C., a styrene-based polymer or styrene-based copolymer is produced by solution polymerization, and the styrene-based polymer or styrene-based copolymer is added with an aromatic divinyl compound or a polymerizable double bond. Two
Carboxylic acid ester having one or more and a styrene monomer or a styrene-based monomer is dissolved in a mixture to perform a suspension polymerization reaction, containing 10 to 70% by weight of tetrahydrofuran insoluble matter, and gel permeation of tetrahydrofuran soluble matter. Weight average molecular weight / number average molecular weight (Mw / Mn) ≧ 5 in the molecular weight distribution by ion chromatography (GPC), at least one peak in the region of molecular weight 2000 to 10,000, and molecular weight 15,000 to 100,000
Has at least one peak or shoulder in the region of and has a molecular weight of 1
10 to 50% by weight of the components below 0000 based on the total resin
The present invention relates to a method for producing a binder resin for toner, which comprises preparing a contained styrene resin composition.

 The configuration of the present invention will be described.

In order to achieve the above-mentioned objects at the same time, various binder resins were used, and the constitution and performance of the binder resins were intensively studied from various angles. As a result, the ratio of the tetrahydrofuran insoluble matter (hereinafter referred to as "THF insoluble matter") of the binder resin and the tetrahydrofuran soluble matter (hereinafter referred to as "THF insoluble matter").
It has been found that this can be achieved with a specific configuration of the molecular weight distribution of the (F soluble component)). When the binder resin is dissolved in a solvent such as THF, it can be separated into insoluble matter and soluble matter, and the soluble matter can be measured for molecular weight distribution by GPC. Focusing on the peaks of the molecular weight distribution of THF-insoluble matter and THF-soluble matter,
The relationship between the position and pulverizability is as shown in FIG.
From this, a system with little or no THF insoluble matter is very disadvantageous in grindability, and as mentioned above, it improves grindability. The direction of shifting to the position proves that the offset resistance is deteriorated and it is difficult to satisfy both the offset resistance and the crushability. From this study, it was found that the inclusion of a specific amount of the THF-insoluble component is very effective not only for resistance to the offset, but also for improving the grindability, as is usually considered.

Furthermore, the molecular weight distribution of THF-soluble matter and the property of whether the fixing temperature is high or low (hereinafter referred to as fixing property), offset resistance, crushing property, and blocking resistance were examined. As a result, first, for example, as shown in FIG. 8, it was found that the molecular weight distribution has a different molecular weight of about 10,000 or less and a molecular weight of about 10,000 or more. That is, the content ratio of the component having a molecular weight of 10,000 or less with respect to the entire binder resin, as is usually said, does not strongly affect the fixing property or the offset resistance, but in a specific range, it is rather related. Instead, it turned out to be strongly related to the grindability. further,
From other considerations, the binder resin is basically THF.
Insoluble matter mainly affects offset resistance, slurability, pulverizability, and THF soluble matter having a molecular weight of 10,000 or less is mainly pulverizability, blocking ability, fusion property to a photoreceptor,
It was found that the filming property and the fusion to the inner wall of the pulverizer were affected, and that the THF-soluble component having a molecular weight of 10,000 or more mainly affects the fixing property. The proportion of components having a molecular weight of 10,000 or less is preferably 10 to 50 wt%, and more preferably 20 to 39 wt%. To get sufficient performance,
Further, the molecular weight is 10,000 or less, 2000 or more (preferably 2000-8
000), and a peak or shoulder is required in the region of molecular weight of 1500 to 100,000 (preferably 20000 to 70000), and there is no peak at 2000 to 10000 and a peak at molecular weight of 2000 or less, or a molecular weight of 10000 or less. 50% by weight of ingredients
If it exceeds the above range, there are some problems such as blocking resistance, fusion to the photoreceptor, filming, fusion to the inner wall of the crushing device. If there is no peak at a molecular weight of 10,000 or less and a peak at 10,000 or more, or if the proportion of low molecular weight components having a molecular weight of 10,000 or less is less than 10 wt%, pulverizability becomes a problem, and formation of coarse particles also becomes a problem.

Further, there is no peak or shoulder in a region having a molecular weight of 15,000 or more, and when there is a peak only in a region having a molecular weight of 15,000 or less, offset resistance, fusion to a photoreceptor, filming,
The problem of fusion to the inner wall of the crusher is a problem. Molecular weight 1500 to 100
If there is no peak or shoulder in the 000 region and there is a main peak at 100,000 or more, the pulverizability becomes a problem.

Further, the THF-soluble content needs to be Mw / Mn ≧ 5, and when Mw / Mn is 5 or less, the offset resistance tends to decrease, which is a problem. Mw / Mn is preferably 80 or less, and more preferably 10 ≦ Mw / Mn ≦ 60. Particularly, when Mw / Mn is 10 ≦ Mw / Mn ≦ 60, excellent properties are exhibited in various properties such as pulverizability, fixing property, offset resistance, and imageability.

Further, the THF insoluble content in the resin must be 10 to 70 wt% (preferably 10 to 60 wt%). If the THF insoluble content is less than 10 wt%, the offset resistance and scatterability will be a problem, and 70 wt%
If it exceeds%, problems such as deterioration of molecular chains due to thermal kneading during toner production may occur. Preferably 15-59
wt% (further preferably 15-49 wt%) is good.

In addition, the glass transition point Tg1 of the resin having a molecular weight of 10,000 or less in the THF-soluble content and the glass transition point Tgt of the entire resin
When comparing Tg1 ≧ Tgt−5, the fixing property, crushing property, fusion to the photosensitive member, filming property, fusion property to the inner wall of the crushing device, blocking resistance, etc. are improved. Found out.

Here, Tg1 is measured by the following method. At a temperature of 25 ° C, THF was caused to flow at a flow rate of 7 ml per minute, and a THF sample solution having a concentration of the THF-soluble component in the resin composition of about 3 mg / ml was poured into a molecular weight distribution measuring device in an amount of about 3 ml to obtain a molecular weight of 10,000. Collect the following ingredients. After collection, the solvent is distilled off under reduced pressure, and further dried in a 90 ° C. atmosphere under reduced pressure for 24 hours. Perform the above operation until about 20 mg of a component with a molecular weight of 10,000 or less is obtained
Annealing is performed for 48 hours, and then Tg is measured by a differential scanning calorimetry method, and this value is defined as Tg1.

As a preparative column, TSKgel G2000H, TSKgel G2500
H, TSKgel G3000H, TSKgel G4000H (Toyo Soda Industry Co., Ltd.) and the like are used.

In the present invention, TSKgel G2000H and TSKgel G3000H were used in combination.

Further, Tgt, which is the Tg of the resin, is obtained by annealing the resin at 50 ° C. for 48 hours and then by the differential scanning calorimetry.

The most preferred embodiment of the present invention is as shown in FIG.
GPC molecular weight of THF-soluble component, molecular weight 15,000-100,00
The height of the highest peak in the 0 region is h ₂ , and the molecular weight is
The highest peak height in the 2,000-10,000 area is h ₁
Then, the resin or resin composition has a ratio of h ₁ / h ₂ of 0.4 to 4.0 / 1. Further, the number average molecular weight of the THF-soluble component is preferably 2000 ≦ Mn ≦ 9000. If Mn <2000,
Offset property becomes a problem, and if 9000 <Mn, crushability and fixability become problems.

The THF-insoluble matter in the present invention refers to the weight ratio of the polymer component (substantially crosslinked polymer) that becomes insoluble in THF in the resin composition, and indicates the degree of crosslinking of the resin composition containing the crosslinking component. It can be used as a parameter to indicate. The THF-insoluble matter is defined as a value measured as follows.

That is, 0.5 to 1.0 g of a resin sample (24 mesh pass, 60 mesh powder) is weighed (W ₁ g), put into a cylindrical filter paper (for example, No.86R manufactured by Toyo Roshi Kaisha, Ltd.), and applied to a Soxhlet extractor, and THF100 as a solvent. Extraction is carried out for 6 hours using ˜200 ml, and the soluble component extracted by the solvent is evaporated, and then vacuum dried at 100 ° C. for several hours, and the amount of THF-soluble resin component is weighed (W ₂ g). The THF insoluble content of the resin is calculated from the following formula.

In the present invention, the molecular weight of the peak or / and the shoulder of the chromatogram by GPC (Gel Vermeation Chromatography) is measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40 ° C, and THF was added as a solvent to the column at this temperature.
(Tetrahydrofuran) is caused to flow at a flow rate of 1 ml per minute, and 50 to 200 μl of a THF sample solution of a resin adjusted to a sample concentration of 0.05 to 0.6% by weight is injected for measurement. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value and the count number of a calibration curve prepared from several kinds of monodisperse polystyrene standard samples. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Che
Mical Co. or Toyo Soda Kogyo Co., Ltd. has a molecular weight of 6 × 10 ² , 2.1 × 10 ³ , 4,5 × 10 ³ , 1.75 × 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10.
⁵ , 3.9 × 10 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , 4.48 × 10 ⁶
It is appropriate to use at least 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

As the column, a plurality of commercially available polystyrene gel columns may be combined in order to accurately measure the molecular weight region of 10 ³ to 2 × 10 ⁶ , for example, μ-st manufactured by Waters.
yragel 500,10 ³ , 10 ⁴ , 10 ⁵ combination, Showa Denko Shodex KF-80M, KF-801,803,804,805 combination, KA-802,803,804,805 combination, or Toyo Soda TSKgel G1000H, G2000H, G25000H, G3000H, G4000H, G
A combination of 5000H, G6000H, G7000H, GMH is preferable.

The weight% of the binder resin of the present invention having a molecular weight of 1000 or less cuts out the molecular weight of 10,000 or less of the chromatogram by GPC, and calculates the weight ratio with the cutout having a molecular weight of 10,000 or more. The weight% with respect to the binder resin is calculated.

As the constituent component of the resin of the present invention, those which are generally used as the resin for toner and various compounds can be used as long as they can achieve the above-mentioned molecular weight distribution. Among them, vinyl monomers are used. Vinyl-based polymers, vinyl-based copolymers, and compositions of the polymers and the copolymers were preferred.

Examples of the vinyl-based monomer (monomer) applicable to the present invention include styrene such as styrene, α-methylstyrene, and p-chlorostyrene and their substitution products; acrylic acid,
Such as methyl acrylate, ethyl acrylate, butyl acrylate, dodecyl acrylate, octyl acrylate, methacrylic acid, methyl methacrylate, ethyl methacrylate, butyl methacrylate, octyl methacrylate, acrylonitrile, methacrylonitrile, acrylamide etc. A monocarboxylic acid having a double bond or a substituted product thereof; for example, a dicarboxylic acid having a double bond such as maleic acid, butyl maleate, methyl maleate, dimethyl maleate and the like; a substituted product thereof; for example, vinyl chloride, vinyl acetate , Vinyl esters such as vinyl benzoate, etc .; vinyl ketones such as vinyl methyl ketone, vinyl exyl ketone, etc .; such as vinyl methyl ether, vinyl ethyl ether, vinyl isobutyl ether, etc. Vinyl monomers vinyl ether and the like can be used singly or two or more. Among these, a combination of a styrene polymer and a styrene copolymer is preferable.

The selection of the type of initiator, the type of solvent and the reaction conditions for producing the resin of the present invention are important factors for obtaining the resin of the present invention. Examples of the initiator include benzoyl peroxide, 1,1-di (t-butylperoxy) -3,3,5-
Trimethylcyclohexane, n-butyl-4,4-di (t
-Butylperoxy) valerate, dicumyl peroxide, α, α'-bis (t-butylperoxydiisopropyl) benzene, t-butylperoxycumene, di-t
-Organic peroxides such as butyl peroxide, azo and diazo compounds such as azobisisobutyronitrile and diazoaminoazobenzene can be used.

As the crosslinkable monomer, a monomer having two or more polymerizable double bonds is used, and examples thereof include aromatic divinyl compounds such as divinylbenzene and divinylnaphthalene;
Examples thereof include carboxylic acid esters having two double bonds such as ethylene glycol diacrylate, ethylene glycol dimethacrylate, and 1,3-butanediol dimethacrylate, which may be used alone or as a mixture. Of these, divinylbenzene is effective.

Further, the resin of the present invention shows a glass transition point value which varies considerably depending on the type and composition of the monomer contained as a component, but a glass transition point in the range of 40 to 80 ° C. is effective. More preferably, the glass transition point is preferably 50 to 65 ° C. in terms of blocking resistance and fixing property. When the glass transition point is lower than 40 ° C., thermal agglomeration caking during toner storage is very likely to occur, and agglomeration trouble is likely to occur in a copying machine. Conversely, the glass transition point is 80 ° C
When it exceeds, the heat fixing efficiency is deteriorated.

In the method for producing the binder resin of the present invention, the first resin is prepared by solution polymerization, the first resin is dissolved in a polymerizable monomer, and the polymerizable resin is added in the presence of the resin and a crosslinking agent. Suspension polymerization of the monomers. Monomers for suspension polymerization 100
The first resin should dissolve 10 to 120 parts by weight, preferably 20 to 100 parts by weight, based on parts by weight, and, in the case of suspension polymerization, a crosslinking agent may be added to the monomer for suspension polymerization. ,
It is preferred to use about 0.1-2.0 wt%. These conditions are
Some variation is allowed depending on the type of initiator and reaction temperature.

A case where the first polymer is dissolved in a monomer and suspension polymerized to obtain the binder resin, a polymer obtained by suspension polymerization without dissolving the first polymer, and a first polymer It has been found that this is different from a blended polymer in which is simply mixed.

The former is that the GPC chromatogram of the THF-soluble content has a slightly higher amount of high-molecular weight than the latter. The former has a molecular weight of 300,000 or more, which is 3 to 25 wt% of the total resin, which is clearly higher than the latter. It is considered that this is because the dissolved first polymer influences the suspension polymerization, which is more than the effect that the polymers are uniformly mixed. In more detail, attached drawing GP
Explain with reference to C chart.

FIG. 1 of the accompanying drawings shows the GPC chart of the THF-soluble component of the resin composition obtained in Example 1 described later. Second
The figure shows the GPC chart of polystyrene prepared by the solution polymerization, which is the first polymerization in Example 1.
The polystyrene was soluble in THF, soluble in styrene monomer and n-butyl acrylate monomer, which were polymerized monomers, and had a main peak at a molecular weight of 3,500.
FIG. 3 shows styrene-acrylic acid n- prepared by the second polymerization under the same conditions except that the polystyrene was not added.
The GPC chart of the THF-soluble content of the butyl copolymer produced by suspension polymerization is shown. The styrene-n-butyl acrylate copolymer had a main peak at a molecular weight of 40,000.

FIG. 4 is a combination of the chart of FIG. 2 and the chart of FIG.

FIG. 5 shows a combination of the chart of FIG. 1 and the chart of FIG. 4 (the solid line portion is shown by a broken line). As is clear from FIG. 5, the resin composition obtained in Example 1 according to the present invention was different from the one obtained by simply mixing separately polymerized polystyrene and styrene-n-butyl acrylate copolymer in GPC chart. Had. In particular, it is found that a polymer component, which was not produced by the styrene-n-butyl acrylate copolymer alone, was produced on the high molecular weight side. This high-molecular-weight component is such that during the suspension polymerization, which is the second-stage polymerization, since the polystyrene prepared by the first-stage solution polymerization is present, the polystyrene acts as a polymerization regulator, As a result, it is considered that the synthesis of THF-insoluble matter and THF-soluble matter of the styrene-n-butyl acrylate copolymer was adjusted. The resin composition according to the present invention,
A THF-insoluble matter, a THF-soluble high molecular weight component, a THF-soluble intermediate molecular weight component and a THF-soluble low molecular weight component are uniformly mixed. In addition, the resin composition according to the present invention has a
It has the ability to generate a new peak in the region of 300,000 or more (preferably 500,000 or more) to adjust the fixing property and offset resistance of the toner.

Further, in the present invention, it is preferable that the GPC of the THF-soluble content of the toner can contain a component having a molecular weight of 300,000 or more in an amount of 5 to 30% by weight (preferably 10 to 30% by weight) based on the binder resin. Further, it is preferable that the GPC of the THF-soluble component of the toner has a clear peak at a molecular weight of 300,000 or more (preferably 500,000 or more) from the viewpoint of further improving offset resistance and wrapping resistance.

The solution polymerization and suspension polymerization according to the present invention will be described below.

As the solvent used in the solution polymerization, xylene, toluene, cumene, cellosolvic acid acid, isopropyl alcohol, benzene or the like is used. For styrene monomers, xylene, toluene or cumene are preferred. It is appropriately selected depending on the polymer to be polymerized. Further, the initiator is di-tert-butyl peroxide, tert-butyl peroxybenzoate, benzoyl peroxide, 2,
Use 2'-azobisisobutyronitrile, 2,2'-azobis (2,4 dimethylvaleronitrile), etc. at a concentration of 0.1 parts by weight or more (preferably 0.4 to 15 parts by weight) per 100 parts by weight of the monomer. To be As the reaction temperature, the solvent used,
Depending on the initiator and polymer to be polymerized, 70 ℃ -18
It is better to do it at 0 ° C. The solution polymerization is preferably carried out with 30 parts by weight to 400 parts by weight of the monomer per 100 parts by weight of the solvent.

In the suspension polymerization, 100 parts by weight or less (preferably 10 to 90 parts by weight) of the monomer is preferably used with respect to 100 parts by weight of the aqueous solvent. As the dispersant that can be used, polyvinyl alcohol, partially saponified polyvinyl alcohol, calcium phosphate and the like are used, and there is an appropriate amount such as the amount of the monomer in the aqueous solvent, but generally 0.05 to 1 part by weight relative to 100 parts by weight of the aqueous solvent. Used. Polymerization temperature is 50-95 ℃
Is suitable, but it should be appropriately selected depending on the initiator used and the intended polymer. As the initiator type, any initiator that is insoluble or sparingly soluble in water can be used. For example, benzoyl peroxide,
tert-butyl peroxyhexanoate is a monomer
It is used in an amount of 0.5 to 10 parts by weight based on 100 parts by weight.

In the toner using the resin of the present invention, in addition to the above-mentioned binder resin component, the following compounds are contained in a ratio smaller than the content of the binder resin component within a range that does not adversely affect the effects of the present invention. May be.

For example, an aliphatic or alicyclic hydrocarbon resin such as silicone resin, polyester, polyurethane, polyamide, epoxy resin, polyvinyl butyral, rosin, modified rosin, terpene resin, phenol resin, low molecular weight polyethylene or low molecular weight polypropylene, aromatic system Petroleum resin, chlorinated paraffin, paraffin wax, etc.

When a magnetic toner is prepared using the binder resin of the present invention, magnetic fine particles are contained in the toner. The magnetic fine particles may be any material that exhibits magnetism or is magnetizable,
For example, metals such as iron, manganese, nickel, cobalt, chrome, magnetite, hematite, various ferrites,
There are McGun alloy, other ferromagnetic alloys, etc., and these have an average particle size of about 0.05 to 5μ (more preferably 0.1 to 1μ)
The fine powder of can be used. The amount of magnetic fine particles contained in the magnetic toner is 15 to 70% by weight based on the total weight of the toner.
Is good.

Further, various substances can be added to the toner according to the present invention for the purpose of controlling coloring and charge. Examples thereof include carbon black, iron black, graphite, nigrosine, metal complexes of monoazo dyes, ultramarine blue, phthalocyanine blue, Hansa yellow, benzidine yellow, quinacridone, and various lake pigments.

The toner prepared from the above-mentioned binder resin, magnetic fine particles, colorant, charge control agent, etc. has a strong resistance to the load received in the developing device, and was not crushed and deteriorated in the durability test.

An ethylene olefin polymer may be used as a fixing aid together with a binder resin.

Here, as the ethylene-based olefin homopolymer or ethylene-based olefin copolymer, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, polyethylene can be used. There are ionomers and the like having a skeleton, and in the above copolymer, the olefin monomer is 50 mol% or more (more preferably 60 mol%).
The above is included.

Next, an electrophotographic method applying a developer using the resin according to the present invention will be described.

In the step of developing an electric latent image with toner, the magnetic brush method, the cascade developing method, the powder cloud method, a method using a conductive magnetic toner described in U.S. Pat.No. 3,909,258, JP-A-53-31136 discloses a method of using a high-resistance magnetic toner. The developer using the resin according to the present invention is also suitable for a developing method using a so-called one-component developer containing magnetic fine particles. In the process of transferring the developed image to the transfer target member,
An electrostatic transfer method such as a corona transfer method or a bias transfer method is used.

Furthermore, in the toner using the binder resin of the present invention,
A blade cleaning method, a fur brush cleaning method, or the like is applied to the step of removing the residual toner on the photosensitive layer or the insulating layer, and is particularly suitable for the blade cleaning method.

Further, the powder image on the member to be transferred needs to be fixed on the member, and as a method therefor, a heat fixing method, a solvent fixing method, a flash fixing method, a laminating fixing method, etc. can be used, but especially a heating method is used. Suitable for roller fixing method.

Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited thereto.

Example 1 200 parts by weight of cumene was placed in a reactor and heated to a reflux temperature. Add 100 parts by weight of styrene monomer and diter
A mixture of 8 parts by weight of t-butyl peroxide was added dropwise under a cumene reflux for 4 hours. Under cumene reflux (146
The polymerization was completed at ℃ -156 ℃) and cumene was removed. The obtained polystyrene was dissolved in THF and had Mw = 3700, Mw / Mn = 2.64, GP
The molecular weight of the main peak of C was 3,500 and Tg = 57 ° C.

30 parts by weight of the above polystyrene was dissolved in the following monomer mixture to obtain a mixed solution.

Partially saponified polyvinyl alcohol in the above mixed solution
170 parts by weight of water in which 0.1 part by weight was dissolved was added to obtain a suspension dispersion liquid. The above dispersion liquid was added to a reactor in which 15 parts by weight of water was charged and the atmosphere was replaced with nitrogen, and a suspension polymerization reaction was carried out at a reaction temperature of 70 to 95 ° C for 6 hours. After the reaction was completed, it was filtered, dehydrated and dried to obtain a composition of polystyrene and a styrene-n-butyl acrylate copolymer. The composition comprises a THF insoluble matter and a THF soluble matter which are uniformly mixed, and polystyrene and styrene-acrylic acid n.
-The butyl copolymer was uniformly mixed. The THF insoluble content (using a resin composition powder of 24 mesh pass and 60 mesh pass) of the obtained resin composition was 25 wt%. Also,
When the molecular weight distribution of the THF-soluble component was measured, it had a peak at the positions of 40,000 and 34, 000, and Mn = 0.55,000, Mw = 130,000, Mw / Mn = 2
4, The molecular weight of 10,000 or less was 25% by weight. In addition, the Tg of the resin
Was 58 ° C., and the glass transition point Tg ₁ of 10,000 or less components separated by GPC was 57 ° C.

 The GPC chromatogram of the THF soluble matter is shown in FIG.

The properties of each resin and resin composition relating to the molecular weight were measured by the following methods.

Using Shodex KF-80M as a column for GPC measurement, it was installed in a 40 ° C heat chamber of a GPC measurement device (150C ALC / GPC manufactured by Waters Co.), a THF flow rate of 1 ml / min, and a detector under the conditions of RI (sample Soluble concentration of about 0.1% by weight) 200μ
GPC was measured by injecting 1 l. As a calibration curve for molecular weight measurement, the molecular weight is 0.5 × 10 ³ , 2.35 × 10 ³ , 10.2 × 10 ³ , 35 × 10 ³ , 1,
10 × 10 ³ , 200 × 10 ³ , 470 × 10 ³ , 1200 × 10 ³ , 2700 × 10 ³ , 8420
A 10 ³ solution of a 10-point monodisperse polystyrene standard substance (Waters) in THF was used.

Example 2 200 parts by weight of cumene was placed in a reactor and heated to the reflux temperature. The following mixture was added dropwise under cumene reflux for 4 hours.

Further, the polymerization was completed under cumene reflux (146 to 156 ° C.) to remove cumene. The obtained styrene-α-methylstyrene copolymer had a Mw = 4500, Mw / Mn = 2.8, a main peak at the position of 4400 in the GPC chart, and Tg = 63 ° C.

30 parts by weight of the above styrene-α-methylstyrene copolymer was dissolved in the following monomer mixture to obtain a mixed solution.

Partially saponified polyvinyl alcohol in the above mixed solution
170 parts by weight of water in which 0.1 part by weight was dissolved was added to obtain a suspension dispersion liquid. 15 parts by weight of water was added, and the above dispersion liquid was added to a reactor purged with nitrogen and reacted at a reaction temperature of 70 to 95 ° C. for 6 hours.
After the reaction was completed, it was filtered, dehydrated and dried to obtain a composition of a styrene-α-methylstyrene copolymer and a styrene-2-ethylhexyl acrylate copolymer.

The THF insoluble content of this composition was 32 wt%. Also THF
When the molecular weight distribution of the soluble component was measured, the molecular weight was 50,4.2.
Has a peak at 10,000 positions, Mn = 0.62, Mw = 130,000, Mw / Mn = 2
The molecular weight of 10,000 or less was 20% by weight. In addition, the Tg of the resin
Was 58 ° C., and the glass transition point Tg ₁ of the 10,000 or less components separated by GPC was 60 ° C.

Example 3 200 parts by weight of cumene was placed in the reactor and heated to the reflux temperature. The following mixture was added dropwise under cumene reflux for 4 hours.

Polymerization was completed under cumene reflux (146-156 ° C) to remove cumene. The obtained styrene-methylmethacrylate copolymer had a main peak at a position of Mw = 3900, Mw / Mn = 2.6, and a molecular weight of 4100, and had Tg = 60 ° C.

The above styrene-methyl methacrylate copolymer, 40
Part by weight was dissolved in the following monomer mixture to give a mixed solution.

Partially saponified polyvinyl alcohol in the above mixed solution
170 parts by weight of water in which 0.1 part by weight was dissolved was added to obtain a suspension dispersion liquid. 15 parts by weight of water was added, and the above dispersion liquid was added to a reactor purged with nitrogen and reacted at a reaction temperature of 70 to 95 ° C. for 6 hours.
After completion of the reaction, filtration, dehydration and drying are carried out to obtain a styrene-methylmethacrylate copolymer and styrene-methacrylic acid n-
A butyl copolymer composition was obtained.

The THF insoluble content of this composition was 35 wt%. Also THF
When the molecular weight distribution of the soluble component was measured, the molecular weight was 40,4.3.
Has a peak at 10,000, Mn = 59,000, Mw = 92,000, Mw / Mn = 16,
The molecular weight of 10,000 or less was 32 wt%. In addition, the Tg of the resin
Was 60 ° C., and the glass transition point Tg ₁ of the 10,000 or less components separated by GPC was 58 ° C.

Example 4 200 parts by weight of cumene was placed in a reactor and heated to a reflux temperature. The following mixture was added dropwise under cumene reflux for 4 hours.

Polymerization was completed under cumene reflux (146-156 ° C) to remove cumene. The obtained polystyrene has Mw = 3700, M
w / Mn = 2.64, Mw peak = 3500, Tg = 57 ° C.

30 parts by weight of the above polystyrene was dissolved in the following monomer mixture to obtain a mixed solution.

To the above mixture, partially saponified polyvinyl alcohol.
170 parts by weight of water in which 1 part by weight was dissolved was added to obtain a suspension dispersion liquid. The above dispersion liquid was added to a reactor in which 15 parts by weight of water was charged and the atmosphere was replaced with nitrogen, and the reaction was carried out at a reaction temperature of 70 to 95 ° C. for 6 hours. After completion of the reaction, polystyrene, styrene-
A composition of n-butyl acrylate copolymer was obtained.

The THF insoluble content of this composition was 44 wt%. Also THF
When the molecular weight distribution of the soluble component was measured, the molecular weight was 40,7.0.
Has a peak at the position of 10,000, Mn = 0.580, Mw = 100,000, Mw / Mn
= 17, and the molecular weight of 10,000 or less was 21 wt%. Furthermore, the Tg of the resin was 56 ° C., and the glass transition point Tg ₁ of 10,000 or less components separated by GPC was 56 ° C.

Example 5 150 parts by weight of cumene was placed in a reactor and heated to the reflux temperature. The following mixture was added dropwise under cumene reflux for 4 hours.

Polymerization was completed under cumene reflux (146-156 ° C) to remove cumene. The obtained styrene-n-butyl acrylate copolymer had a main peak at the position of Mw = 6900, Mw / Mn = 2.3, and a molecular weight of 7100, and Tg = 75 ° C.

30 parts by weight of the above polystyrene was dissolved in the following monomer mixture to obtain a mixed solution.

Partially saponified polyvinyl alcohol in the above mixed solution
170 parts by weight of water in which 0.1 part by weight was dissolved was added to obtain a suspension dispersion liquid. 15 parts by weight of water was added, and the above dispersion liquid was added to a reactor purged with nitrogen and reacted at a reaction temperature of 70 to 95 ° C. for 6 hours.
After completion of the reaction, the composition was filtered, dehydrated and dried to obtain a composition of a styrene-n-butyl acrylate copolymer and a styrene-n-butyl methacrylic acid copolymer.

The THF insoluble content of this composition was 30 wt%. Also THF
When the molecular weight distribution of the soluble component was measured, it had peaks at 0.75 million and 43,000, Mn = 0.65 million, Mw = 100,000, Mw / Mn = 15, molecular weight 1
Less than 10,000 was 18 wt%. Further, the Tg of the resin was 61 ° C., and the glass transition point Tg ₁ of 10,000 or less components separated by GPC was 70 ° C.

Comparative Example 1 To the above mixture, partially saponified polyvinyl alcohol.
170 parts by weight of water in which 1 part by weight was dissolved was added to obtain a suspension dispersion liquid. 15 parts by weight of water was added, and the above dispersion liquid was added to a reactor purged with nitrogen and reacted at a reaction temperature of 70 to 95 ° C. for 6 hours. After completion of the reaction, styrene-acrylic acid n was filtered, dehydrated and dried.
-Butyl copolymer was obtained.

The THF insoluble content of this composition was 58 wt%. Also THF
When the molecular weight distribution of the soluble component was measured, it had a unique peak at 40,000, and Mn = 14,000, Mw = 110,000, Mw / Mn = 8 were obtained.

Comparative Example 2 200 parts by weight of cumene was placed in a reactor and heated to the reflux temperature. A mixture of 100 parts by weight of styrene and 8 parts by weight of di-tert-butyl peroxide was added to the mixture under reflux with cumene.
It dripped over time. Under cumene reflux (146 ° C ~ 156 ° C)
(° C) completed the polymerization and removed cumene. The obtained polystyrene had a main peak at a position of Mw = 3700, Mw / Mn = 2.64 and a molecular weight of 3500, and had Tg = 57 ° C.

30 parts by weight of the above polystyrene was dissolved in the following monomer mixture to prepare a mixed solution.

Partially saponified polyvinyl alcohol in the above mixed solution
170 parts by weight of water in which 0.1 part by weight was dissolved was added to obtain a suspension dispersion liquid. 15 parts by weight of water was added, and the above dispersion liquid was added to a reactor purged with nitrogen and reacted at a reaction temperature of 70 to 95 ° C. for 6 hours.
After the reaction was completed, it was filtered, dehydrated and dried to obtain a composition of polystyrene and a styrene-n-butyl acrylate copolymer.

The THF insoluble content of this composition was 75 wt%. Also THF
When the molecular weight distribution of the soluble component was measured, it had a peak at 0.340 million, and Mn = 0.210,000, Mw = 4020,000, Mw / Mn = 2, and a molecular weight of 10,000 or less was 18 wt%. Furthermore, the Tg of the resin was 58 ° C., and the glass transition point Tg ₁ of 10,000 or less components separated by GPC was 57 ° C.

Comparative Example 3 200 parts by weight of cumene was placed in the reactor and heated to the reflux temperature. A mixture of 100 parts by weight of styrene and 8 parts by weight of di-tert-butyl peroxide was added to the mixture under reflux with cumene.
It dripped over time. Under cumene reflux (146 ° C ~ 156 ° C)
(° C) completed the polymerization and removed cumene. The obtained polystyrene had a main peak at a position of Mw = 5300, Mw / Mn = 2.65 and a molecular weight of 5300, and had Tg = 56 ° C.

30 parts by weight of the above polystyrene was dissolved in the following monomer mixture to prepare a mixed solution.

Partially saponified polyvinyl alcohol in the above mixed solution
170 parts by weight of water in which 0.1 part by weight was dissolved was added to obtain a suspension dispersion liquid. The above dispersion liquid was added to a reactor in which 15 parts by weight of water was charged and the atmosphere was replaced with nitrogen, and the reaction was carried out at a reaction temperature of 70 to 95 ° C. for 6 hours. After the reaction was completed, it was filtered, dehydrated and dried to obtain a composition of polystyrene and a styrene-n-butyl acrylate copolymer.

The THF insoluble content of this composition was 30 wt%. Also, T
When the molecular weight distribution of the HF soluble component was measured, it had peaks at 40,000 and 150,000, and Mn = 60,000, Mw = 250,000, Mw / Mn = 42, and a molecular weight of 10,000 or less was 22 wt%. Furthermore, the Tg of the resin is 56 ° C.
The glass transition temperature Tg ₁ of the components of 10,000 or less separated by GPC was 56 ° C.

Production Example 1 100 parts by weight of the resin composition of Example 1, 60 parts by weight of a magnetic material, 4 parts by weight of low molecular weight polypropylene, and 2 parts by weight of a positive charge control agent were heat-kneaded, and a fine pulverizer and a classifier were used. ,
A toner was manufactured.

The pulverizability of this toner raw material was very good, and a treatment amount of 15.3 Kg / hr was obtained in order to obtain a volume average diameter of 10 μ in a pulverized particle size. There was no fusion in the crusher.

A developer prepared by mixing 100 parts by weight of this toner with 0.4 parts by weight of hydrophobic silica was placed in a Canon copying machine NP-5540, and image quality and fixability were evaluated.

After running 50,000 sheets, a stable and good image was obtained.
Further, the fixing property was also very good, and the offset property and the winding property were also good. Furthermore, there was no filming or fusion to the photoreceptor.

Production Example 2 Production Example 1 except that the resin composition of Example 2 is used
The same result as in Production Example 1 was obtained.

Production Examples 3 to 5 and Comparative Production Examples 1 to 4 Toners were produced in the same manner as in Production Example 1 except that the resin compositions of Examples 3, 4 and 5 were used (Production Examples 3 to 3).
5). On the other hand, a toner was produced in the same manner as in Production Example 1 except that the polystyrene used as the raw material of the resin composition in Example 1 and the resin compositions of Comparative Examples 1, 2, and 3 were used (Comparative Production). Examples 1-4). The results are shown in the table.

Evaluation method For the pulverizability of the toner raw material, the amount of treatment per unit time at an air pressure of 5.5 Kg / cm ² was measured with a fine pulverizer using a jet air flow. At the same time, the inner wall of the fine pulverizer was observed to examine the presence or absence of fusion.

The fixing property, the offset property, the winding property, the image property, and the durability were examined by using a Canon NP-5540 copying machine.

Especially the offset property, the set temperature of the fixing device is lowered by 5 ° C,
The cleaning mechanism of the fixing roller was removed, and it was evaluated whether the image was soiled or the roller was soiled.

The fixability was expressed by the reduction rate (%) of the reflection density when the image was rubbed with Silbon C paper and reciprocated 10 times and a load of about 100 g was applied. The evaluation image was viewed at the 200th sheet when 200 sheets were continuously taken.

The wrapping property was judged by how much the nail depended on the appearance of three black images on the entire surface and the marks of the peeling tabs of the fixing roller on the image at that time.

[Brief description of drawings]

In the attached drawings, FIG. 1 shows the GPC chart of the THF-soluble content of the resin composition prepared in Example 1. FIG. 2 shows a GPC chart of polystyrene used in Example 1, and FIG. 3 shows styrene used in Example 1.
The GPC chart of the THF soluble component obtained by suspension polymerization of an n-butyl acrylate copolymer alone is shown. FIG. 4 is a combination of the charts of FIGS. 2 and 3, and FIG. 5 shows a chart for comparing and explaining FIGS. 1 and 4. FIG. 6 is a diagram showing the correlation of each property required for the toner, FIG. 7 is a graph showing the relation between the content of THF insoluble matter and pulverizability, and FIG. 8 is a molecular weight of 1000.
3 is a graph showing the correlation between the content of components of 0 or less and the toner characteristics.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location G03G 9/087

Claims (4)

[Claims] 1. In the molecular weight distribution by gel permeation chromatography (GPC), the molecular weight is 2,000 to 10,0.
It has a main peak in the 00 region and has a weight average molecular weight / number average molecular weight (Mw / Mn) ≦ 3.5 and a glass transition point (Tg) ≧ 50 ° C.
A styrene-based polymer or styrene-based copolymer is produced by solution polymerization, and the styrene-based polymer or styrene-based copolymer is an aromatic divinyl compound or a carboxylic acid having two or more polymerizable double bonds. Acid ester and a suspension polymerization reaction by dissolving in a mixture containing at least a styrene monomer or a styrenic monomer, containing 10 to 70 wt% of tetrahydrofuran insoluble matter, gel permeation chromatography (GPC ), The weight average molecular weight /
Number average molecular weight (Mw / Mn) ≧ 5, molecular weight 2000 to 10,000
It has at least one peak in the 0 region and has a molecular weight of 15,000.
It has at least one peak or shoulder in the region of up to 100,000, and a component with a molecular weight of 10,000 or less is 10 based on the total resin.
A method for producing a binder resin for a toner, comprising preparing a styrene resin composition containing 50% by weight to 50% by weight. 2. The method for producing a binder resin for a toner according to claim 1, wherein the mixture further contains an acrylic monomer or a methacrylic monomer. 3. The method for producing a binder resin for toner according to claim 1, wherein the aromatic divinyl compound is divinylbenzene or divinylnaphthalene. 4. A carboxylic acid ester having two or more polymerizable double bonds is ethylene glycol diacrylate, ethylene glycol dimethacrylate or 1,3-
The method for producing a binder resin for toner according to claim 1, wherein the binder resin is butanediol dimethacrylate.