JPH01214872A - Electrostatic charge image developing toner - Google Patents

Abstract

PURPOSE:To obtain a toner good in folding resistance, fixable at low temperature, and preventing melt attaching to a photosensitive body and filming during uses for a long period in a high-speed system by using a binder resin specified in molecular weight distribution. CONSTITUTION:The binder resin of the toner has a content of a fraction insoluble in tetrahydrofuran (THF) of <10wt.%, and in the content of a fraction soluble in THF, a fraction w1 having a molecular weight of <=10,000 is 10-50wt.% in the molecular weight distribution measured by the gel permeation chromatography (GPC), and a fraction w2 having a molecular weight of >=500,000wt.% is 5-30wt.% and a w2/w1 ratio is 0.05-2.0. A peak exists in the region of <=10,000mol.wt. by GPC in the fraction soluble in THF, and said fraction has a glass transition point of >=55 deg.C, thus permitting the obtained electrostatic charge image developing toner to be superior in folding resistance and blocking resistance, usable in an atmosphere of high temperature, fixable at low temperature, free from melt attaching to the photosensitive body and filming in a high speed system and during uses for a long period.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a toner for developing electrostatic images in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to a toner for developing electrostatic images suitable for constant fixation on a heated roller.

[Prior art] Conventionally, as an electrophotographic method, U.S. Patent No. 2,297゜13
Although many methods are known, as described in Japanese Patent Publication No. 91, Japanese Patent Publication No. 42-23910, and Japanese Patent Publication No. 43-24748, etc., in general, photoconductive substances are used and various means are used. forms an electrical latent image on the photoreceptor,
Next, the latent image is developed using toner, and after the toner image is transferred to a transfer material such as paper as necessary, it is fixed by heat, pressure, heat and pressure, solvent vapor, etc. to obtain a copy. The toner remaining on the photoreceptor without being transferred is cleaned by various methods, and the above-described steps are repeated.

In recent years, such copying devices have begun to be used not only as office copying machines for copying original manuscripts, but also as printers that serve as a powerful computer or as personal copiers for individuals.

For this reason, smaller size, lighter weight, higher speed, and higher reliability are being strictly pursued.

Machines are in many ways becoming composed of simpler elements. As a result, the performance required of toner has become more advanced, and it has become impossible to create better machines unless the performance of toner can be improved.

For example, various methods and apparatuses have been developed for the process of fixing a toner image on a sheet such as paper, but the most common method at present is a compression heating method using a heated roller.

The pressure heating method using a heated roller performs fixing by passing the toner image surface of the sheet to be fixed under pressure while contacting the surface of a heated roller whose surface is made of a material that has releasability for toner. . In this method, the surface of the heat roller and the toner image on the sheet to be fixed come into contact with each other under pressure, so the thermal efficiency when fusing the toner image onto the sheet to be fixed is extremely good, and the fixing can be performed quickly. It is very effective in high-speed electrophotographic copying machines. However, in the above method, since the surface of the heat roller and the toner image contact each other under pressure in a molten state, a portion of the toner image adheres to and transfers to the surface of the fixing roller, and this is transferred again to the next sheet to be fixed, resulting in so-called This may cause an offset phenomenon and stain the fixing sheet. Preventing toner from adhering to the surface of the heat fixing roller is considered to be one of the essential conditions for the heat roller fixed fixing method.

Conventionally, in order to prevent toner from adhering to the fixing roller surface, for example, the roller surface was made of a material with excellent release properties for toner, such as silicone rubber or fluorine resin, and the surface was also coated with anti-offset and roller surface coatings. In order to prevent fatigue, the roller surface is coated with a thin film of a liquid with good mold releasability, such as silicone oil.

However, although this method is extremely effective in preventing toner offset, it requires a device to supply the offset prevention liquid, resulting in problems such as the complexity of the fixing device. .

This is in the opposite direction to miniaturization and weight reduction, and what's more, silicone oil and other substances may evaporate due to heat and contaminate the interior of the aircraft. Therefore, instead of using a silicone oil supply device, the idea was to supply an anti-offset liquid from within the toner during heating, and a method was adopted in which a release agent such as low molecular weight polyethylene or low molecular weight polypropylene was added to the toner. is proposed. If a large amount of such additives is added in order to obtain a sufficient effect, it may cause filming on the photoreceptor or contaminate the surface of a toner carrier such as a carrier or sleeve, deteriorating the image and causing practical problems. Therefore, a small amount of release agent is added to the toner to the extent that it does not deteriorate the image.
A device for cleaning the toner by supplying a small amount of release oil or using a winding-type member such as a web to take up the offset toner is used in conjunction with the cleaning device.

However, considering the recent demands for smaller size, lighter weight, and higher reliability, it is necessary and desirable to eliminate even these auxiliary devices. This is difficult to achieve without further improvement of the binder resin of the toner. As a technique for improving the binder resin of a toner, for example, Japanese Patent Publication No. 51-23354 proposes a toner using a crosslinked polymer as a binder resin. If this method is followed, it will be effective in improving offset resistance and clinging resistance, but on the other hand, if the degree of crosslinking is increased, the fixing point will rise, and the fixing temperature will be sufficiently low, resulting in good offset resistance and clinging resistance. Generally speaking, in order to improve fixing properties, it is necessary to lower the softening point of the binder resin by lowering its molecular weight.What are the measures to improve offset resistance? This is contradictory, and in order to achieve a low softening point, the glass transition point of the resin inevitably decreases, resulting in an undesirable phenomenon of blocking of the toner during storage.

In order to solve this problem, Japanese Patent Laid-Open No. 158340/1983 proposes a toner consisting of a low molecular weight polymer and a high molecular weight polymer, but this toner has a low fixing temperature, good offset resistance, and sufficient fixing properties. In general, in order to improve offset resistance, it is necessary to increase the molecular weight of the high molecular weight component or increase the ratio, and this direction tends to increase the fixing temperature and is not satisfactory for practical purposes. is difficult to obtain.

Furthermore, for example, Japanese Patent Publication No. 80-20411 proposes a resin composition composed of a low molecular weight polymer and a high molecular weight polymer by polymerizing monomers in the presence of a high molecular weight polymer.
Similarly to the above, in order to improve offset resistance, it is necessary to increase the molecular weight of the high molecular weight component or increase the ratio, which also tends to increase the fixing temperature, making it difficult to obtain something that is practically satisfactory. .

Furthermore, regarding a toner that is a blend of a low molecular weight polymer and a crosslinked polymer, for example, Japanese Patent Laid-Open No. 58-88558 proposes a toner that has a low molecular weight polymer and an infusible high molecular weight polymer as main resin components. There is. If that method is followed, fixing properties tend to be improved, but the weight average molecular weight/number average molecular weight (Mw/Mn) of the low molecular weight polymer is 3.
5 or less and the content of the insoluble and infusible high molecular weight polymer is as large as 40 to 90 wt%, it is difficult to satisfy both offset resistance and fixing performance with high performance, and in practice, offset It is extremely difficult to produce toner that fully satisfies fixing properties and anti-offset properties unless the toner is used in a fixing device equipped with a supply device for a prevention liquid.

Furthermore, if there is a large amount of insoluble, infusible high molecular weight polymer, the melt viscosity will become extremely high during heat kneading during toner production, so it must be heat kneaded at a much higher temperature than usual, or heat kneaded at a high shear. As a result, the former has the problem of deterioration of toner properties due to thermal decomposition of other additives, and the latter has the problem that the molecules of the binder resin are excessively cut, making it difficult to achieve the original offset resistance performance.

Furthermore, in Japanese Patent Application Laid-open No. 130-188958, a low molecular weight polyα having a number average molecular weight (Mn) of 500 to 1,500
- A toner comprising a resin composition obtained by polymerization in the presence of methylstyrene has been proposed.

In particular, in this publication, the number average molecular weight (In) is from 9,000 to
It is said that a range of 30.000 is preferable, but as Mn is increased to further improve offset resistance, fixing performance becomes a practical problem, and therefore it is difficult to satisfy offset resistance and fixing performance with high performance. .

Furthermore, JP-A-58-18144 discloses that a toner containing a binder resin component having at least one maximum value in each region of molecular weight 103 to 8 x 104 and molecular weight 105 to 2 x 106 in the molecular weight distribution by GPC is disclosed. Proposed. In this case, the toner has excellent offset resistance, fixing properties, filming on photoreceptor, and fusing image properties, but it is desired to further improve the offset resistance and fixing properties of the toner. In particular, it is difficult for such resins to meet today's strict demands while maintaining or improving various other properties by further improving fixing properties.

In this way, it is extremely difficult to achieve high performance related to fixing. Furthermore, copies to which toner has been fixed are often folded in half or in quarters due to storage needs.

During such folding, the image at the folded portion may be peeled off from the copy, resulting in poor image quality, and it is therefore necessary to maintain good image quality even during such folding.

In addition, miniaturization requires that each element be neatly housed in a narrow space, which reduces the space for air to flow properly, and the heat source of the fuser and exposure system is very close to the toner hopper and cleaner. , the toner is exposed to a high temperature atmosphere. Therefore, it has become impossible to put toners into practical use unless they have better anti-blocking properties.

As described above, the various performances required of a toner are often contradictory, and although it is increasingly desired to satisfy both of them with high performance and research is being conducted, there is still no satisfactory one.

[Problems to be Solved by the Invention] An object of the present invention is to provide a toner that solves the above-mentioned problems.

The objects of the present invention are listed below.

An object of the present invention is to provide a toner with good bending resistance.

An object of the present invention is to provide a toner suitable for a hot roll fixing method that does not apply oil.

An object of the present invention is to provide a toner suitable for a cleaning method using a blade.

The purpose of the present invention is to fix at a low temperature, fuse to a photoreceptor,
It is an object of the present invention to provide a toner that does not cause filming even in high-speed systems and even after long-term use.

SUMMARY OF THE INVENTION An object of the present invention is to provide a toner that can be fixed at low temperatures, has excellent anti-blocking properties, and can be used satisfactorily even in high-temperature atmospheres, especially in small machines.

[Means for Solving the Problem] That is, the present invention solves the problem by reducing THF of the binder resin in the toner.
The content of insoluble matter is less than 10% by weight (based on the binder resin), and in the molecular weight distribution of the HF-soluble part of the binder resin by GPC, the weight w1 of the component of 10,000 or less is 10 to 50% by weight. .

The weight movement of components of 500.000 or more is 5 to 30% by weight, and the w2/w+ ratio is 0.05 to 2.0.
It has a peak in the region below 10.000 pC, and THF
The present invention relates to a toner for developing electrostatic images, characterized in that the glass transition point of the soluble component having a molecular weight of 10,000 or less is 55°C or higher, and the glass transition point of the toner is 55°C or higher.

The present invention will be explained in detail below.

In order to achieve the above objectives at the same time, various binder resins were used, and their composition and performance were carefully studied from various angles. As a result, it was found that this can be achieved when the ratio of the THF-insoluble portion of the binder resin and the molecular weight distribution of the ↑HF-soluble portion are in a specific configuration. When the binder resin is dissolved in a solvent such as THF, it can be separated into an insoluble component and a soluble component, and the molecular weight distribution of the soluble component can be measured by GPC.

The molecular weight distribution of the THF soluble content, the property of whether the fixable temperature is high or low (hereinafter simply referred to as fixability), bending resistance, and blocking resistance were investigated. As a result, G
Molecular weight of 10,000 or less and about 10 in PC molecular weight distribution
It has been found that components having a molecular weight of ,000 or more have different functions. In other words, the content ratio W1 of components having a molecular weight of 10,000 or less with respect to the entire binder resin does not strongly affect fixing properties or anti-offset properties, as is usually said, but rather has little effect on it within a specific range. It was found that there was no relationship between the two, but instead it was strongly related to the crushability.

Furthermore, other studies have shown that the content ratio w2 of components of soo, ooo or higher mainly affects the offset resistance, wrapping property, and bending resistance of the binder resin, and the molecular weight of the THF-soluble component is 10. ,000 or less mainly affects the crushability, blocking property, adhesion to the photoreceptor, filming property, etc., and the components with a molecular weight of 10,000 or more that are soluble in IF mainly affect the It was found that this has an effect on fixing properties. The proportion of components with a molecular weight of 10,000 or less is preferably 10 to 50 wt%, preferably 10 to 50 wt%.
It is 39wt%. In order to achieve sufficient performance, the molecular weight should be 10,000 or less, with a peak in the region of 2,000 or more (preferably 2,000 to 8,000), and a molecular weight of 15,000 to 200,000 (preferably A peak or shoulder is required in the region of 20,000 to 15,000). There is no peak between 2,000 and 10,000, and there is a peak at a molecular weight of 2.000 or less, but if the proportion of components with a molecular weight of 10 or less is 50 wt% or more, blocking resistance, fusion to the photoreceptor, There is no peak at molecular weights below 6 io, ooo, which causes some problems with filming, and there is a peak at molecular weights above 10,000, but if the proportion of components with a molecular weight of 10,000 or less is less than 10 wt%, grindability becomes a problem. , the generation of coarse particles is also a problem.

Also, if there is no peak or shoulder in the region of molecular weight 15,000 or more, and there is a peak only in the region of molecular weight 15,000 or less, offset resistance becomes a problem.
If there is no peak or shoulder in the region of 000 to 200.000, and there is a main peak above 200.000, the crushability becomes a problem.

Furthermore, it is necessary that the THF soluble content is Mu/Mn≧5, and when My/Mn is 5 or less, offset resistance
This increases the tendency for bending resistance to decrease, which becomes a problem.

Preferably, Nw/Mn is 80 or less, and more preferably lO≦X/Mn≦80.

In particular, when Nw/In is 10≦Nw/Mn≦80, particularly excellent performance is exhibited in various properties such as fixing properties, offset resistance, bending resistance, and image quality.

Note that My here is a weight average molecular weight measured by GPC described below, and In is a number average molecular weight measured in a similar manner.

And an additional 500.00 for the binder resin of the toner.
5 to 30 wt% of the component of 0 or more is required.

If the content of soo, ooo or higher components is less than 5 wt %, offset resistance and bending resistance will become a problem, and if it is more than 30 wt %, problems will arise such as deterioration such as molecular chain breakage due to hot kneading during toner production. Preferably, the content of the component of 500,000 or more is 5 to 25 wt%, which is good in terms of offset resistance and bendability.

Furthermore, the ratio of w2/wI is required to be in the range of 0.05 to 2.0. If it is less than 0.05, there will be problems with offset resistance and bending resistance, and if it is more than 2.0, there will be problems such as high fixing temperature and deterioration such as molecular chain breakage due to heat kneading during toner production. Preferably, the ratio w2/IN is 0.1
The range of ~20 is good, and the TI of the toner binder resin
(The F insoluble content is required to be less than 10% by weight.

If it exceeds 10% by weight, problems will arise regarding bending resistance. Such THF-insoluble content is preferably less than 5% by weight.

In addition, when comparing the glass transition point Tgl of the resin with a molecular weight of 10,000 or less in the molecular weight distribution of the THF soluble component and the glass transition point Tgt of the entire toner, it was found that the Tgl was 55°C or higher,
When the temperature is 55° C. or higher, fixing properties, bending resistance, adhesion to the photoreceptor, filming properties, blocking resistance, etc. become better.

Tgl here is measured by the following method. THF was flowed at a flow rate of 7 tsll per minute at a temperature of 25°C, and the concentration of THF-soluble components in the toner was 3 mg/min.
■! About 3 ml of THF sample solution was injected into a molecular weight distribution analyzer, and after 0 fraction fractionation to separate components with a molecular weight of 10,000 or less, the solvent was distilled off under reduced pressure, and further 2 mL of THF sample solution was injected under reduced pressure in a 90'0 atmosphere.
The above operation was repeated until about 20 g of a component with a molecular weight of 10,000 or less, which was dried for 4 hours, was obtained, followed by 7 two-rings at 50°C for 48 hours. After this, tg was measured by differential scanning calorimetry. , this value is set as Tgl.

The measurement at this time is based on the generally known ASTM0341 standard.
It was carried out according to method B-82.

That is, the temperature was increased to 120°C or higher by measuring the temperature increase of 10°C/in, held there for about 10 minutes, rapidly cooled to 0°C, held there for 10 minutes, and then raised at a rate of 10°C/win. Obtain the endothermic curve.

Tg is defined by the intersection of the median line of the baseline and the inflection curve.

As a preparative column, TSKgel G2000H,T
SKgel G2500H, TSKgel G3000H
, TSKgel G4000H (both Toyo Soda Kogyo ■)
However, in the present invention, TSKgel G200
A combination of 0H and TSKgel G3000H was used.

Also, the value of gt, which is the Tg of the toner, is
Annealed for 48 hours and then determined by differential scanning calorimetry.

In the most preferred embodiment of the present invention, as shown in FIG.
The height of the highest peak in the region of 000 to 200,000 is h2, and the molecular weight is 2. If the height of the highest peak in the region of Goo ~ 10,000 is hl, then ht/h2
The toner contains a binder resin having a ratio of 0.2 to 3.0/1. Furthermore, regarding the number average molecular weight of the THF-soluble component, it is preferable that 2,000≦Mn≦9,000; if In<2,000, problems such as offset property and bending resistance will arise; When Goo<In, pulverization and fixing properties become a problem.

The THF-insoluble content in the present invention refers to the weight percentage of the polymer component (substantially crosslinked polymer) that has become insoluble in the THF solvent in the resin composition in the toner, and refers to the weight percentage of the polymer component (substantially crosslinked polymer) in the resin composition in the toner. It can be used as a parameter indicating the degree of crosslinking. The THF-insoluble content is defined by the value measured as follows.

That is, weigh out 0.5 to 1.0 g of toner sample (1 g), put it in a thimble filter paper (Toyo Roshi Department No. 88R), apply it to a Soxhlet extractor, and add THF100 as a solvent.
After extraction with ~200 tjj for 6 hours and evaporating the soluble components extracted by the solvent.

Vacuum dry at 100°C for several hours, then weigh the amount of TIIF-soluble resin component (W2g),) Let the weight of components other than the resin component such as magnetic material or pigment in the chi be (W3g), and THF-insoluble content is , can be obtained from the following formula.

In the present invention, the molecular weight of a chromatographic peak and/or shoulder by GPC (gel permeation chromatography) is measured under the following conditions.

That is, the column was stabilized in a heat chamber at 40°C, and THF was added to the column at this temperature as a solvent.
(Tetrahydrofuran) is flowed at a flow rate of 1++1+ per minute, and 50 to 200 μ of a THF sample solution of the resin adjusted to a sample concentration of 0.05 to 0.8% by weight is injected and measured. In measuring the molecular weight of the sample, the molecular weight distribution of the sample was calculated from the relationship between the logarithm value and the count number of a calibration curve prepared using several types of monodisperse polystyrene standard samples. Standard polystyrene samples for creating a calibration curve include, for example, Pressuy6 Chemical Co.
or manufactured by Toyo Tsudani Gyosha with a molecular weight of 6X102.2
．． lX103. 4X103.1.75 X104゜5
, IX 104.1. IX 105.3.9X 10
5.8.8X 105゜2 X 106.4.48X
It is appropriate to use at least 10 standard polystyrene samples. Further, an R1 (refractive index) detector is used as a detector.

In order to accurately measure the molecular weight range from 103 to 106 x 106, it is recommended to use a combination of commercially available polystyrene gel columns, such as JJ-styragel 500.103.104 manufactured by Waters.
．． 105 combination and 5hodex manufactured by Showa Denko
KF-80%, KF-802, 803, 804, 80
5 combination or Toyo Sodabu's TSKgel G1
00OH, G2QOOH, G25G0H.

G3000H, G4000H, G5000H, Ge00
A combination of 0H, G100OH, and GMH is preferred.

The weight % based on the binder resin with a molecular weight of 10,000 or less and the weight % based on the binder resin with a molecular weight of 50,000 or more in the present invention is a molecular weight of 10.00 in the chromatogram by GPC.
Calculate the weight ratio of cutouts with a molecular weight of 0 or less and cutouts with molecular weights of 1o and ooo or more, and use the weight% of the THF-insoluble content to calculate the weight% with respect to the entire binder resin.

Moreover, w2/wl is indicated by the weight ratio of each component.

To evaluate the bendability, make a black image on the entire surface, fold it so that the image surfaces overlap and rub it back and forth 10 times with a load of about 200g, and rub the image on the folded part 10 times back and forth with Silbon paper and paper.
00. The image was rubbed under a load, and the peeling of the image was expressed as the rate of decrease in reflection density (%).

The resin composition in the toner of the present invention is preferably one obtained by polymerizing one or more monomers selected from styrenes, acrylic acids, methacrylic acids, and derivatives thereof from the viewpoint of development characteristics and charging characteristics. Examples of - include styrene, α-methylstyrene, vinyltoluene, chlorostyrene, and the like.

Acrylic acids, methacrylic acids and their derivatives include acrylic acid, methyl acrylate, ethyl acrylate,
Propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n acrylate
- Acrylic acid esters such as -tetradecyl, n-hexadecyl acrylate, lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, and dimethylaminoethyl acrylate, as well as methacrylic acid, methyl methacrylate, ethyl methacrylate,
Propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-methacrylate
Ethylhexyl, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-methacrylate
Examples include methacrylic acid esters such as -hydroxypropyl, dimethylaminoethyl methacrylate, glycidyl methacrylate, and stearyl methacrylate. In addition to the above-mentioned monomers, small amounts of other monomers such as acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, vinylcarbazole,
Vinyl methyl ether, butadiene, isoprene, maleic anhydride.

Maleic acid, maleic monoesters, maleic diesters, vinyl acetate, etc. may also be used.

The crosslinking agent used in the toner of the present invention includes divinylbenzene as a bifunctional crosslinking agent.

Bis(4-7cryloxy, polyethoxyphenyl)propane, ethylene glycol diacrylate.

1.3-Butylene gelicol diacrylate, l,4-
butanediol diacrylate) + lj-bentanediol diacrylate, 1,13-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate.

Triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol 11200. 400. Each diacrylate of cloud 800,
Examples include dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type diacrylate (NANDA Nippon Kayaku), and those obtained by replacing the above acrylates with methacrylates.

As polyfunctional crosslinking agents, pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis(4-methacryloxy, polyethoxyphenyl) Propane, diallyl phthalate, triallyl cyanurate, triallyl asocyanurate, triallyl isocyanurate.

Examples include triallyl trimellitate and diarylchlorendate.

The method for synthesizing the binder resin according to the present invention basically consists of two steps.
A method of synthesizing more than one type of polymer is preferred.

That is, a resin composition is obtained by dissolving a first polymer that is soluble in TIIF and soluble in polymerization monomer in a polymerization monomer, and polymerizing the polymer.

In this case, a composition is formed in which the former and latter polymers are uniformly mixed.

The first polymer soluble in THF is preferably subjected to solution polymerization or ionic polymerization, and the second polymer for producing a component insoluble in THF is prepared under the conditions in which the first polymer is dissolved. The first polymer is preferably synthesized by suspension polymerization or bulk polymerization in the presence of a crosslinkable monomer. Preferably, parts by weight are used.

FIG. 2 of the accompanying drawings shows a GPC chart of the THF soluble content of the resin composition obtained in Synthesis Example 1, which will be described later.

FIG. 3 shows a GPC chart of polystyrene prepared by solution polymerization, which is the first polymerization. The polystyrene was soluble in THF, soluble in styrene monomer and n-butyl acrylate monomer as polymerization monomers, and had a main peak at a molecular weight of 3,500. Figure 4 is a GPC chart of the THF soluble content of a styrene-n-butyl acrylate copolymer produced by suspension polymerization, which was prepared in the second polymerization under the same conditions except that the polystyrene was not added. It shows. The styrene-n-butyl acrylate copolymer had a main peak at a molecular weight of 40,000.

FIG. 5 is a combination of the chart in FIG. 3 and the chart in FIG. 4.

FIG. 6 shows a combination of the chart in FIG. 2 and the chart in FIG. 5 (solid line portions are indicated by broken lines). As is clear from FIG. 6, the resin composition obtained in Synthesis Example 1 according to the present invention has a GPC chart different from that of a simple mixture of separately polymerized polystyrene and styrene-n-butyl acrylate copolymer. It had In particular, it was found that a high molecular component, which was not produced in the styrene-n-butyl acrylate copolymer alone, was produced on the high molecular weight side. This high molecular weight component is caused by the presence of polystyrene prepared in the first stage solution polymerization during suspension polymerization, which is the second stage polymerization. It is thought that as a result, the synthesis of THF-insoluble and THF-soluble components of the styrene-n-butyl acrylate copolymer was adjusted. high molecular weight component, T
The HF-soluble intermediate molecular weight component and the THF-soluble low molecular weight component are uniformly mixed.

Furthermore, in the present invention, GPC of the HF soluble portion of the toner
The component having a molecular weight of 500,000 or more is 5 to 30% by weight (preferably 5 to 25% by weight) based on the binder resin.
In addition, those having a clear peak at a molecular weight of 500,000 or more in the GPC of the HF-soluble portion of the toner are preferred from the standpoint of improving offset resistance and bending resistance.

In such a polymerization method, it is preferable to use a small amount of the above-mentioned crosslinking agent. By using a small amount of the crosslinking agent in combination, G
15,000-200.00 in molecular weight distribution of PC
It becomes possible to increase the content ratio of components of 500,000 or more without causing a change that would affect the peak position in the range of 0 for practical purposes.

Generally, when polymerization is carried out for such purposes, delicate adjustments are made to the polymerization temperature and the amount of polymerization initiator added, but these may cause high costs in terms of equipment, or Problems such as a longer polymerization reaction time are likely to occur, and furthermore, the peak position is large and tends to shift to the high molecular weight side, making it difficult to adjust the molecular weight within a specific range. The molecular weight can be adjusted relatively easily. The amount of such a crosslinking agent added is preferably 0.1% by weight or less, more preferably 0.07% by weight or less, based on the polymerizable substance during polymerization.

As the charge control agent used in the toner of the present invention, a conventionally known positive or negative charge control agent can be used. Charge control agents known in the art today include the following:

(1) The following substances can be used to control the toner to be positively charged.

Nigrosine, azine dyes containing an alkyl group having 2 to 1B carbon atoms (Japanese Patent Publication No. 1827/1983), basic dyes (
For example, C,1,Ba5ic Yellow 2 (C,
1,41000), C, 1, Basic Yellow
3, C, 1, Ba5ic Red l (C-1゜4
5160), C,1,Ba5ic Red 9 (C
, 1,42500), C,l-Ba5ic Viole
t 1 (C, 1, 42535), C, 1, Ba5ic
Violets (C, 1, 42555), C, 1,
Ba5ic Violet 1G (C, 1°45170
), C,1,Ba5ic Violet 14 (C,
1,42510).

C,1,Ba5ic Blue 1 (C,1,420
25), C,1,Ba5icBlue 3 (C,1
, 51005), C, 1, Ba5ic Blue 5
(C, l-42140), C, 1, Ba5ic Blue
e 7 (C, 1, 42595), C, I.

Ba5ic Blue 8 (C, 1, 5201
5), C,1,Ba5ic Blue 24(
C,1,52030), C,1,Ba5ic Blue
25 (C, 1, 52025).

C,1,Ba5ic Blue 2B (C,1,44
025), C, IJagicGreen (+reen
1 (C,1,42040), C,1,913ic
Lake pigments of these basic dyes such as Green 4 C, 1,42000) (lake-forming agents include phosphotungstic acid, phosphomolybdic acid, phosphotungsten molybdic acid, tannin melt, lauric acid, gallic acid.

ferricyanide, ferrocyanide, etc.), C,1,
5ovent Black 3 (C, 1, 2f115
G), Banza Yellow G (C, 1, 11880)
, C, 1, Mardlant Blackll.

C, 1, Pig ent Black 1st grade.

Or 1 For example, pencil methyl-hexadecyl ammonium chloride, decyl-trimethyl ammonium chloride, or dialkyltin compounds such as dibutyl and dioctyl, metal salts of higher fatty acids, glass, mica, inorganic fine powder such as lead oxide, EDTA, acetylacetone Polyamine resins such as metal complexes, vinyl polymers containing amino groups, condensation polymers containing amino groups, nigrosine, metal salts of higher resin acids, vinyl polymers containing amine groups, etc. Polymers and the like are preferred.

(2) The following substances can be used to control the negative chargeability of toner. Special Publication No. 41-20153, No. 42-2759
E1.

Examples include metal complexes of heptanoazo dyes described in JP-A No. 444397 and JP-A No. 45-26478.

Dyes and pigments such as nitrofumic acid and its salts or C,1,14845 described in JP-A No. 50-133338, JP-B No. 55-42752, JP-B No. 58-4150
No. 8, Special Publication No. 58-7384, Special Publication No. 59-7384
metal complexes of salicylic acid, naphthoic acid, guicarboxylic acid such as Zn, AR, Co, Or, Fe, etc., sulfonated copper phthalocyanine pigments, nitrile groups, styrene oligomers with halogens introduced, chlorinated paraffins, etc. In particular, from the viewpoint of dispersibility, metal complexes of heptanoazo dyes, metal complexes of salicylic acid, alkylsalicylic acid, naphthoic acid, and guicarboxylic acid are preferred.

Good results can be obtained with the toner of the present invention even when additives are mixed therein as required. Examples of additives include lubricants such as Teflon, zinc stearate, and polyvinylidene fluoride, preferably polyvinylidene fluoride, or abrasives such as cerium oxide, silicon carbide, and strontium titanate, particularly strontium titanate. Alternatively, a fluidity imparting agent such as colloidal silica or aluminum oxide, preferably hydrophobic colloidal silica, an anti-caking agent, or a conductivity imparting agent such as carbon black, zinc oxide, antimony oxide, tin oxide, or a low molecular weight Examples include fixing aids such as polyethylene, low molecular weight polypropylene, various waxes, and anti-offset agents. Further, a small amount of white fine particles and black fine particles of opposite polarity can be used as a developing property improving agent.

Further, when the toner of the present invention is used as a two-component developer, it is used in combination with a carrier powder. In this case, the mixing ratio of toner and carrier powder is desirably 0.1 to 50% by weight, preferably 0.5 to 10% by weight, and more preferably 3 to 5% by weight in terms of toner concentration.

Known carriers can be used in the present invention, such as magnetic powders such as iron powder, ferrite powder, nickel powder, glass beads, etc., and their surfaces coated with fluorine-based resin or silicone-based resin. Examples include those whose surface has been treated with, etc.

Furthermore, the toner of the present invention can further contain a magnetic material and be used as a magnetic toner. In this case, the magnetic material also serves as a colorant. The magnetic materials contained in the magnetic toner of the present invention include iron oxides such as magnetite, hematite, and ferrite, or compounds of divalent metals and iron oxides: iron;
cobalt.

Metals such as nickel or these metals with aluminum, cobalt, copper, lead, -gnesium, tin, zinc,
antimony, beryllium, bismuth.

cadmium, calcium, manganese, selenium, titanium,
Examples include alloys of metals such as tungsten and vanadium, and mixtures thereof.

These ferromagnetic materials preferably have an average particle size of 0.1 to 2 μm, preferably 0.1 to 0.5 μm, and spherical ones are particularly preferred. About 20 to 200 parts by weight per 100 parts by weight,
Particularly preferably 40 to 18 parts by weight per 100 parts by weight of the resin component.
0 parts by weight is good.

Furthermore, a coloring agent may be added to the toner of the present invention if necessary.

Any suitable pigment or dye can be used as the colorant used in the toner of the present invention. Toner colorants are well known and include pigments such as carbon black, aniline black, acetylene black, naphthol yellow,
Hansa yellow.

Examples include rhodamine lake, alizarin lake, red iron, phthalocyanine blue, and indan strenblue. These are used in a necessary and sufficient amount to maintain the optical density of the fixed image, and the addition amount is preferably 0.1 to 20 parts by weight, preferably 2 to 10 parts by weight, per 100 parts by weight of the resin. For this purpose, dyes may be used, such as azo dyes, anthraquinone dyes, xanthine dyes, methine dyes, etc. 0.1 to 20 parts by weight, preferably 0.3 to 3 parts by weight, per 100 parts by weight of the resin. The amount of addition is good.

To prepare the toner for developing an electrostatic image according to the present invention, the resin composition and charge control agent according to the present invention, if necessary, a magnetic material, a pigment or dye as a coloring agent, additives, etc. are mixed in a ball mill or other machine. After thoroughly mixing with a mixer, the pigment or dye is dispersed or dissolved in the resin by melting, kneading, and kneading using a heat kneader such as a heated roll, niegu, or extruder to make the resins mutually soluble. After cooling and solidifying, the toner is crushed and classified to obtain a toner layer having an average particle size of 3 to 20 μm.

Margin below [Example] The parts in the following formulations are parts by weight.

Synthesis Example 1 200 parts of cumene was placed in a reactor, and the temperature was raised to reflux temperature. This is combined with styrene monomers tooff and tert.
- A mixture of 4 parts of butyl peroxide was added dropwise over 4 hours under cumene reflux. Furthermore, under reflux of cumene (14 parts
The solution polymerization was completed at ~158° C.) and the cumene was removed.

The obtained polystyrene is soluble in THF and Mw=
3,700, My/Mn = 2J4, and the molecular weight at which the main peak of GPG was located was 3,500°Tg = 57°C. A GPC chart of the polystyrene is shown in FIG.

Dissolve 30 parts of the above polystyrene in the following monomer mixture,
A mixed solution was prepared.

Add 0% of the partially saponified polyvinyl alcohol to the above mixed solution.
170 parts of water in which 1 part was dissolved was added to form a suspension dispersion. The above suspended molecules and axillary were added to a reactor containing 15 parts of water and purged with nitrogen, and the suspension polymerization reaction was carried out for 6 hours at a reaction temperature of 70 to 95°C. After the completion of the reaction, it was separated from the furnace, dehydrated, dried, and made into polystyrene. A composition of styrene-n-butyl acrylate copolymer was obtained. In the composition, THF-insoluble and THF-soluble components were uniformly mixed, and polystyrene and styrene-n-butyl acrylate copolymer were uniformly mixed. THF-insoluble portion of the obtained resin composition (24 mesh passes).

(measured using 80 mesh powder) was 1 wt% or less. In addition, when the molecular weight distribution of THF-soluble components was measured, there were peaks at approximately 4,000 and 33,000 positions in the GPC chart, Mn = 0,590,000, Mw = 15
10,000, Mw/Mn”= 25, molecular weight less than 10,000 is 2
It was 8wt%. Furthermore, the Tg of the resin is 59°C,
The glass transition point Tg+ of the components of 10,000 or less separated by GPC was 58°C. W2/W+ was approximately 0.3.

A GPC chromatogram of the THF-soluble fraction is shown in FIG.

In addition, the characteristics related to the molecular weight of each resin and resin composition were measured by the following method.

5hodex K F-80 as a column for ape measurement
1, using a GPCJ11 constant apparatus (made by Utters Co., Ltd.
By injecting a sample (concentration of 0.1% by weight of THF-soluble matter) at 200 ui) into a 40°C heat chamber with a THF flow rate of 1 mid/win and a detector of R1. GPC measured 0
The calibration curve for molecular weight measurement is molecular weight 0.5 x 103
．． 2.35 x 103.10.2 x 1G3゜35
X 103. ll0X 103.200X 103.
470X 103, 1200X103, 2700X
A THF solution of 10 points of monodisperse polystyrene reference material (manufactured by Waters) measuring 1G3.8420×103 was used.

Comparative Synthesis Example 2 30 parts of the polystyrene obtained in Synthesis Example 1 was dissolved in the following monomer mixture to prepare a mixed solution.

The above mixture was subjected to suspension polymerization in the same manner as in Synthesis Example 1 to obtain a composition of polystyrene and styrene-n-butyl acrylate copolymer. The THF-insoluble content of this resin composition is 75
% by weight, and contained a large amount of HF insoluble matter.

Comparative Synthesis Example 2 30 parts of the polystyrene obtained in Synthesis Example 1 was dissolved in the following monomer mixture to prepare a mixed solution.

The above mixture was subjected to suspension polymerization in the same manner as in Synthesis Example 1 to obtain a composition of polystyrene and styrene-n-butyl acrylate copolymer. GPC of the HF soluble components of this composition
There were peaks at molecular weights of 4,000 and 150,000.

Comparative Synthesis Example 3 150 parts of xylene is placed in a reactor and the temperature is raised to reflux temperature. To this, 100 parts of styrene monomer, tert-
A mixture of 2 parts of butyl peroxybenzoate and 1 part of di-tert butyl peroxide was heated under refluxing xylene for 4 hours.
It dripped over time. Furthermore, xylene (138-144
The solution polymerization was completed at 10°C (°C) and the xylene was removed.

The obtained polystyrene is soluble in THF and Mw=
10,000, My/Mn = 3.22. Molecular weight 11
There is a main peak at the position of ,000, Tg = 82℃
Met.

Dissolve 30 parts of the above polystyrene in the following monomer mixture,
A mixed solution was prepared.

The above mixture was subjected to suspension polymerization in the same manner as in Synthesis Example 1 to obtain a composition of polystyrene and styrene-n-butyl acrylate copolymer. GPC of THF soluble components of this composition
There was virtually no peak at a molecular weight of 10,000 or less.

Comparative Synthesis Example 4 170 parts of water in which 0.1 part of partially saponified polyvinyl alcohol was dissolved was added to the following monomer mixture to prepare a suspension dispersion.

The above dispersion was added to a reactor containing 15 parts of water and purged with nitrogen, and a suspension polymerization reaction was carried out at a reaction temperature of 70 to 85°C for 6 hours. An n-butyl copolymer was obtained.

This copolymer has a main peak with a molecular weight of 17.000.
There was virtually no peak at a molecular weight of 10,000 or less.

Synthesis Example 2 150 parts of cumene was placed in a reactor, and the temperature was raised to reflux temperature. The following mixture was added dropwise to the cumene over 4 hours under reflux.

Polymerization was completed under roughly cumene reflux (146-158°C) and cumene was removed. The obtained styrene-n-butyl acrylate copolymer had Mw=8,900, Nw/Mn
= 2.3, had a main peak at a molecular weight of 7,100, and had a Tg of 80°C.

40 parts of the above styrene-n-butyl acrylate copolymer was dissolved in the following monomer mixture to form a mixture.

Add 0.1% of partially saponified polyvinyl alcohol to the above mixture.
170 parts of water was added to prepare a suspension and dispersion.

The above dispersion was added to a reactor filled with 15 parts of water and purged with nitrogen, and reacted for 6 hours at a reaction temperature of 70 to 95°C. After the reaction was completed, it was separated from the furnace, dehydrated, dried, and styrene-acrylic acid n-
A composition of a butyl copolymer and a styrene-n-butyl methacrylate copolymer was obtained.

Synthesis Example 3 200 parts of cumene was placed in a reactor, and the temperature was raised to reflux temperature. The following mixture was added dropwise to the cumene over 4 hours under reflux.

Furthermore, polymerization was completed under cumene reflux (148 to 156°C), and cumene was removed. The obtained polystyrene has Mw
= 4,300. Mw/Mn=2.84. Molecular weight 4
, 200, and Tg=84°C. 30 parts of the above polystyrene was dissolved in the following monomer mixture to form a mixture.

Add 0.1% of partially saponified polyvinyl alcohol to the above mixture.
170 parts of water was added to prepare a suspension and dispersion.

The above dispersion was added to a reactor containing 15 parts of water and purged with nitrogen, and reacted for 6 hours at a temperature of 70 to 95°C per reactor.After the completion of the 6 reactions, the reactor was separated, dehydrated and dried, and then mixed with polystyrene and styrene.
A composition of 2-ethylhexyl acrylate copolymer was obtained.

Synthesis Example 4 150 parts of cumene was placed in a reactor, and the temperature was raised to reflux temperature. The following mixture was added dropwise to the cumene over 4 hours under reflux.

Further, the polymerization was completed under cumene reflux (148-158°C), and cumene was removed. The obtained polystyrene has Mw=
5,200. Nw/Mn=2.74, molecular weight 5,
It had a main peak at 300°C, and 1 g = 75°C.

Dissolve 30 parts of the above polystyrene in the following monomer mixture,
It was made into a mixture.

Add 0.1% of partially saponified polyvinyl alcohol to the above mixture.
170 parts of water was added to prepare a suspension and dispersion. water 1
The above dispersion was added to a reactor containing 5 parts and purged with nitrogen,
After the reaction was completed for 6 hours at a reaction temperature of 70 to 95°C, the mixture was separated in a furnace, dehydrated, and dried to obtain a composition of polystyrene and styrene-n-butyl acrylate copolymer.

Synthesis Example 5 200 parts of cumene was placed in a reactor and the temperature was raised to reflux temperature. The following mixture was added dropwise to the cumene over 4 hours under reflux.

Furthermore, polymerization was completed under cumene reflux (146 to 156°C), and cumene was removed. The obtained styrene-methyl methacrylate copolymer has M trade=a, aoo, Mu/I
n = 2.8, molecular weight 4,300, main beak at position (7), and Tg = 115°C. 15 parts of the above styrene-methyl methacrylate copolymer was dissolved in the following monomer mixture to form a mixture.

Add 0.1% of partially saponified polyvinyl alcohol to the above mixture.
170 parts of water was added to prepare a dispersion. The above dispersion was added to a reactor containing 15 parts of water and purged with nitrogen, and reacted at a reaction temperature of 70 to 85°C for 6 hours. After the reaction was completed, the mixture was separated into a furnace, dehydrated, dried, and styrene-methyl methacrylate copolymerized. A composition of styrene-n-butyl acrylate copolymer was obtained.

Synthesis Example 6 200 parts of cumene was placed in a reactor, and the temperature was raised to reflux temperature. The following mixture was added dropwise to the cumene over 4 hours under reflux.

Furthermore, polymerization was completed under cumene reflux (148 to 158°C), and cumene was removed. The obtained styrene-α-methylstyrene has Mw = 4,500, Mw/Mn = 2
．． 8. Has a main peak at a molecular weight of 4,400,
Tg was 63°C.

30 parts of the above styrene-α-methylstyrene copolymer was dissolved in the following monomer mixture to form a mixture.

Add 0.1% of partially saponified polyvinyl alcohol to the above mixture.
170 parts of water was added to prepare a suspension and dispersion. water 1
The above dispersion was added to a reactor containing 5 parts and purged with nitrogen,
After the reaction was completed for 6 hours at a reaction temperature of 70 to 85°C, the mixture was separated in a furnace, dehydrated, and dried to obtain a composition of styrene-α-methylstyrene copolymer and styrene-n-butyl acrylate copolymer. Ta.

Example 1 After premixing the above materials in a Henschel mixer, 150
The mixture was kneaded for 15 minutes in a two-roll mill heated to .degree. After allowing the mixture to cool, it was roughly pulverized with a cutter mill, then pulverized with a pulverizer using a jet stream, and further classified using an air classifier to obtain a black fine powder with a volume average particle size of 11.5 μm. I got a body. A GPC chart of the THF soluble content of the black fine powder is shown in FIG.

0.4 parts of colloidal silica fine powder was dry mixed with 100 parts of the black fine powder to obtain a developer (toner).

In addition, the blocking property is as follows: Approximately 10g of toner is
The samples were placed in a polycop tube (c) and left at 50°C for one day, and the changes after aggregation were examined. The degree of aggregation was measured using a wire micron powder tester. The product left at room temperature and the product left at 50°C for one day showed almost the same values at 10% by weight and 12% by weight, and the difference (ΔG) was 2%, confirming that there was no substantial blocking.

Image quality, durability, and bending resistance are based on Canon copier N.
This was investigated using P-2702.

The image quality was evaluated on the 200th sheet of 200 consecutive sheets.

In addition, a durability test was conducted using images with an image area ratio of 5% for approximately to, 00 sheets, and one image was found to be good.

Comparative Examples 1 to 4 Toners were made in the same manner as in Example 1 using the resin compositions prepared in Comparative Synthesis Examples 1 to 4 instead of the resin compositions of Examples, and the toners were used as Comparative Examples 1 to 4. did.

The toner of the comparative example was evaluated in the same manner as in Example 1 and is shown in Table 1.

Table 1 Example 2 A toner was prepared using the above mixture in the same manner as in Example 1.

The volume average particle size was 11.71A11.

The coloital silicone fine powder was treated with amino-modified silicone oil.

In addition, the image quality is improved with the Canon personal copier FIC-5.
The retention relationship was evaluated.

As a result, the image was good and continued to appear until the toner ran out, and the bendability was also good.

Example 3 A toner was produced in the same manner except that the resin composition of Example 2 was changed to the resin composition of Synthesis Example 3.

The volume average particle size of the toner was 11.3 pm.

The blocking property was ΔG=2%, and there was no problem at all.

In addition, image quality and fixing were evaluated using a Canon HP-5540 copying machine (OPC photoreceptor, 40 sheets per minute).

As a result, the images were good and stable even after 20,000 sheets of durability. The bending resistance was also good. Example 4 A toner was produced in the same manner except that the resin composition of Example 2 was changed to the resin composition of Synthesis Example 4. The volume average particle size of the toner was 11.7 microns. The blocking property is
There was no problem at all at ΔG=3%.

Furthermore, image quality and fixing were evaluated using a digital copying machine MP-13030 manufactured by Canon that uses an amorphous Si photoreceptor. As a result, the image was good, and a stable image was obtained after 30,000 sheets of durability. The bending resistance was also good.

Example 5 A toner was produced in the same manner except that the resin composition of Example 1 was changed to the resin composition of Synthesis Example 5. The volume average particle size of the toner was 11.4 pi+. The blocking property was ΔG=3%, with no problem at all.

In addition, image quality was obtained using a Canon copier MP-400RE11.

The retention relationship was evaluated.

As a result, the image was good and stable even after 20,000 sheets of durability. The bending resistance was also good. Example 6 A toner was prepared from the above mixture by the method of Example 1, and the toner was mixed with iron powder having a particle size of 200 to 300 mesh in an amount of about 10% by weight, and mixed with a developer. did. Further, only toner was used as a replenisher. The blocking property was ΔG=4%, and there was no problem at all.

Further, the image properties and fixing properties were evaluated using a Canon string high-speed copying machine MP-8500 Super. As a result, the image was good and stable even after 50,000 sheets of durability. The bendability was also good.

Table 2 shows the characteristics of the toner.

[Effects of the Invention] As is clear from the above, the toner of the present invention has excellent bending resistance.

Further, the toner of the present invention is fixed at a low temperature, and does not cause fusion or filming to the photoreceptor even in high-speed systems or after long-term use.

Furthermore, it can be fixed at low temperatures and has excellent anti-blocking properties, so it can be used satisfactorily even in high-temperature atmospheres, especially in small machines.

[Brief explanation of the drawing]

FIG. 1 shows a GPC chart of the THF-soluble content of the toner prepared in Example 1, and FIG. 2 shows a GPC chart of the THF-soluble content of the resin composition prepared in Synthesis Example 1. Figure 3 shows a GPC chart of polystyrene used in Synthesis Example 1, and Figure 4 shows a THF sample obtained by suspension polymerizing the styrene-n-butyl acrylate copolymer used in Synthesis Example 1 alone. Figure 5, which shows a GPC chart of soluble content, is a combination of the charts in Figures 3 and 4, and Figure 6 shows a chart for comparing and explaining Figures 2 and 5. , FIG. 7 is a graph showing the correlation between the content of components having a molecular weight of 10,000 or less and toner characteristics.

Claims (1)

[Claims] In a toner for developing an electrostatic image having at least a binder resin and a colorant, the content of the THF-insoluble part of the binder resin is less than 10% by weight (based on the binder resin), and the molecular weight distribution of the THF-soluble part of the binder resin is determined by GPC. , the weight of the components below 10,000 w_1
is 10 to 50% by weight, the weight W_2 of the 500,000 or more components is 5 to 30% by weight, and w_2/w_1
The ratio of 0.05 to 2.0 and 10,000
It has a peak in the following region, and the molecular weight of the THF-soluble portion is 10.
,000 or less has a glass transition point of 55° C. or higher, and the toner has a glass transition point of 55° C. or higher.