JPH03243958A - Toner for developing electrostatic charge image and image forming method using same - Google Patents

Abstract

PURPOSE:To ensure superior anti-offsetting property and blocking resistance for a toner and to prevent filming by specifying the percentage of the THF- insoluble component of the toner, the mol. wt. distribution of the THF-soluble components and the glass transition temp. of the toner. CONSTITUTION:When a toner is composed essentially of binding resins, a charge controlling agent and a colorant, the content of the THF-insoluble component of the toner is regulated to <=20wt.%, a mol. wt. distribution having at least one peak in the region of <30,000mol.wt., at least one peak or shoulder in the region of 30,000-1,000,000mol.wt. and at least one peak or shoulder in the region of >1,000,000mol.wt. is rendered to the THF-soluble components and the glass transition temp. of the toner is regulated to 50-70 deg.C. Superior fixability, anti-offsetting property and blocking resistance are ensured for the toner and filming on a developing roller is prevented.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a method for developing electrostatic images (electrostatic latent images) formed in electrophotography, electrostatic recording, electrostatic printing, etc. The present invention relates to a dry toner and an image forming method using the same.

[Conventional technology]

Conventional electrophotographic methods include US Pat. No. 2,297,691, Japanese Patent Publication No. 42-23910 and Japanese Patent Publication No. 43
Many methods are known, as described in Japanese Patent No. 24748, etc., but generally they use photoconductive substances,
An electrical latent image is formed on the photoreceptor by various means, then the latent image is developed using toner, and if necessary, the toner image is transferred to a transfer material such as paper, followed by heating, pressure, or heating. Copies are obtained by fixing using pressure or solvent vapor. 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 copy machines for copying original manuscripts, but also as printers for computer output or as personal copiers for individuals.

Therefore, smaller size, lighter weight, higher speed, and higher reliability are being strictly pursued, and one machine is being constructed of simpler elements in various respects.

As a result, the performance required of toner has become more advanced.
Unless improvements in toner performance are achieved, better machines will no longer be possible.

For example, various methods and devices 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 press-heating method using a heated roller. The pressure heating method using a heated roller fixes the toner by passing the toner image surface of the sheet to be fixed under pressure through the surface of a heated roller whose surface is made of a material that has releasability to the toner. It is something to do.

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 carried out quickly. It is very effective in high-speed electrophotographic copying machines. However, in this method, the surface of the heated roller and the toner image contact each other under pressure in a molten state.
A part of the toner image adheres to and transfers to the surface of the fixing roller, and is transferred again to the next sheet to be fixed, causing an offset phenomenon, which may stain the sheet to be fixed. Therefore, one of the essential conditions for the heat roller fixed fixing method is to prevent toner from adhering to the heat fixing roller surface.

Conventionally, in order to prevent the toner from fixing on the surface of the fixing roller, for example, the roller surface is made of a material that has excellent releasability for the toner, such as silicone rubber or fluorine resin, and the surface is also made of a material that prevents offset. In order to prevent fatigue on the roller surface, the roller is coated with a thin film of liquid such as silicone oil that has good mold releasability. However, although this method is extremely effective in preventing toner offset, it requires a device for supplying offset prevention liquid.

This has problems such as the fixing device becoming complicated. This is in the opposite direction to miniaturization and weight reduction, and silicone oil and other substances may evaporate due to heat and contaminate the interior of the aircraft.

Therefore, without using a silicone oil supply device,
Instead, a method of adding a mold release agent such as low molecular weight polyethylene or low molecular weight polypropylene to the toner has been proposed based on the idea of supplying an anti-offset liquid from the toner during heating. However, if such additives are added in large quantities to achieve sufficient effects, they may cause filming on the photoconductor or contaminate the surface of toner carriers such as carriers and sleeves, resulting in image deterioration. This poses a practical problem.

Therefore, a small amount of release agent is added to the toner to the extent that the image does not deteriorate, and at the same time, a small amount of release oil is supplied, or the offset toner is cleaned using a winding member such as a web. things are being done. However, considering the recent demands for smaller size, lighter weight, and higher reliability, it is necessary and desirable to eliminate even these auxiliary devices such as the releasing oil supply device or the cleaning device. The above requirements cannot be met without further improvement in performance with respect to fixing, offset, etc., and this is difficult to achieve without further improvement in the binder resin of the toner.

Regarding the improvement of 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.

According to this method, offset resistance and wrapping resistance are improved, but there is a drawback that increasing the degree of crosslinking increases the fixing point. Moreover, no one having sufficient fixing properties has been obtained.

Generally, in order to improve fixing properties, it is necessary to lower the softening point by lowering the molecular weight of the binder resin, which is contradictory to the treatment to improve offset resistance. This inevitably lowers the glass transition temperature of the resin, resulting in the undesirable phenomenon of blocking of the toner during storage.

On the other hand, in Japanese Patent Application Laid-open No. 56-158340,
A toner made of a low molecular weight polymer and a high molecular weight polymer has been proposed, but it is actually difficult to incorporate a crosslinking component into this binder resin, and in order to achieve higher performance and improve offset resistance, It is necessary to increase the molecular weight of the high molecular weight polymer or increase its ratio. However, this method significantly reduces the crushability, and it is difficult to obtain a product 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 Application Laid-Open No. 86558/1989 discloses a toner that has a low molecular weight polymer and an insoluble high molecular weight polymer as main resin components. Proposed. By this method, fixing properties and crushability will be improved to some extent, but the weight average molecular weight/number average molecular weight ratio (Mu/Mn) of the low molecular weight polymer is as small as 3.5 or less, and the insoluble and infusible Due to the high content of 40 to 90% by weight of the anti-offset polymer, it is difficult to achieve high performance in both anti-offset and crushability. Unless the toner is used in a fixed fixing device, it is extremely difficult to produce a toner that fully satisfies fixing properties (especially high-speed fixing properties), anti-offset properties, and crushability. Furthermore,
When the insoluble polymer has a large molecular weight, the melt viscosity becomes extremely high during heat kneading during toner production, so it is necessary to heat knead at a much higher temperature than usual or with a high shear. As a result, in the former case, toner properties deteriorate due to thermal decomposition of other additives, and in the latter case, slight cleavage of the binder resin molecules occurs, and when combined with a low molecular weight polymer with Mw/Mn≦3.5, the toner properties deteriorate. The problem is that offset performance is difficult to achieve.

Furthermore, JP-A-60-166958 discloses a toner comprising a resin composition obtained by polymerization in the presence of low molecular weight polyα-methylstyrene having a number average molecular weight (Mn) of 500 to 1,500. Proposed. In particular, in this publication, the number average molecular weight (Mn) is 900-30,000
However, if Mn is increased in order to further improve offset resistance, fixing performance and pulverization during toner production will actually become a problem. is difficult to satisfy. In this way, a toner with poor pulverization properties during toner production is undesirable because not only does the production efficiency during toner production decrease, but also rough toner tends to be mixed in due to the toner characteristics, which may result in scattered images.

Furthermore, in JP-A-56-16144, in the molecular weight distribution by gel permeation chromatography (hereinafter abbreviated as GPC), at least 1 A toner containing a binder resin component having two maximum values has been proposed.Furthermore, in JP-A-58-82258, molecular weight 10ζ8X10' by GPC, molecular weight 1
A dry-component developer containing a binder resin component having at least one maximum value or shoulder in each region of 0' to 10!1 molecular weight 106 or more has been proposed. These toners or single-component developers are excellent in terms of crushability, anti-offset properties, image quality, and filming and fusing to photoreceptors, but there is a need for further improvements in anti-offset properties and fixing properties. has been done. In particular, it is difficult for the above-mentioned resins to meet today's strict demands while further improving fixing properties and maintaining or improving various other performances.

[Problem to be solved by the invention]

As mentioned above, conventional toners have not been able to fully meet the needs of copying devices that have become smaller, lighter, and faster in recent years, and are particularly inadequate in terms of offset resistance and fixing properties. be. Moreover, recently, cleaning using a blade (blade cleaning) has become common in view of the miniaturization, weight reduction, and reliability of devices. Furthermore, as the lifespan of photoreceptors increases, toners are required to have greater resistance to adhesion and filming to the photoreceptor. In particular, 0PC
The lifespan of organic photoreceptors (organic photoreceptors) is also increasing, and the various performances required of toners are therefore becoming more advanced. In addition, miniaturization requires fitting each element into 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. Therefore, 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.

Therefore, the first object of the present invention is to provide a toner suitable for a fixed fixing method using a heated roller without applying oil.
A second object of the present invention is to provide a toner with excellent offset resistance. Furthermore, the third object of the present invention is to provide a toner that does not cause fusion or filming on a photoreceptor even in a high-speed system or during long-term use, and also has anti-blocking properties. The fourth object is to provide a toner that can be used satisfactorily even in a high-temperature atmosphere in an excellent small machine, and the fifth object is to provide a toner that can form stable and good developed images.

[Means to solve the problem]

In order to simultaneously achieve the above objectives, the present inventors investigated the composition and performance of various toners from various angles, and as a result, the ratio of the tetrahydrofuran-insoluble content and the tetrahydrofuran-soluble content of the toner was determined. The present inventors have discovered that the above object can be achieved when the molecular weight distribution has a specific configuration and the glass transition point is specific. That is, according to the present invention, at least a binder resin, In a toner comprising a charge control agent and a colorant, the content of tetrahydrofuran insoluble matter in the toner is 20% by weight or less,
In addition, in the molecular weight distribution of the tetrahydrofuran soluble portion of the toner measured by gel permeation chromatography,
having at least one peak in a region with a molecular weight of less than 30,000,
The toner has at least one peak or shoulder in the molecular weight range of 30,000 to 1 million, and has at least one peak or shoulder in the molecular weight range of over 1 million, and has a glass transition temperature of 50 to 70°C. Provided is a toner for developing electrostatic images characterized by the following.

Further, there is provided an image forming method using the toner described above, in an image forming method using a one-component development method in electrophotography, in which a thin layer of toner is supplied to a latent image carrier to develop a latent image. Ru.

In the toner of the present invention, the tetrahydrofuran (
The insoluble content (hereinafter abbreviated as THF) is 20% by weight or less. When the THF-insoluble content is 20% by weight or less, the offset resistance of the toner is improved. If the THF-insoluble content exceeds 20 weight, the toner tends to be offset to the fixing roller.

Note that the THF-insoluble content herein is defined as a value measured as follows. That is, toner sample 0
．． Accurately weigh 5±0,005g into a 20(lIli2) Erlenmeyer flask, and add 50m of T)lF. Thereafter, the mixture is stirred and heated on a hot stirrer and refluxed for 3 hours. The contents were filtered through a glass filter (Bg) packed with Celite #545 in advance. The gel adhering to the wall surface is also transferred to a glass filter, placed in a vacuum dryer at 80°C and left at normal pressure for 30 minutes, then dried under reduced pressure for 2.5 hours (degree of vacuum 750 mHg or higher). Thereafter, it is cooled to room temperature in a desiccator and weighed accurately. T.H.
The F-insoluble content is determined from the following formula.

-B THF insoluble content (%) = X100 where W = sample collection amount (g) A = weight of the glass filter after filtering the sample (g) B = weight of the glass filter before filtering the sample (g) In the toner of the present invention, the THF-soluble content must first have at least one peak in a molecular weight region of less than 30,000. This component with a molecular weight of less than 30,000 is mainly pulverizable.

Affects blocking properties, adhesion to photoreceptors, and filming properties. Furthermore, the THF-soluble component must have at least one peak or shoulder in the molecular weight range of 30,000 to 1,000,000.
The component of 1,000 or more mainly affects the fixing performance, and if the component is missing, the fixing performance becomes poor. Furthermore, the THF-soluble content is required to have at least one peak or shoulder in the region with a molecular weight of over 1,000,000. If this component is not present, a problem will arise in fixing properties even if a component having a molecular weight of 30,000 to 1,000,000 is present.

Note that the TI (F soluble content) herein is defined as the value measured as follows. That is, 3 g of toner sample was weighed, placed in a thimble filter, subjected to a Soxhlet extractor, and 100% hexane was added as a solvent. Extract for 6 hours using 100% chloroform.Furthermore, extract for 6 hours using 100% chloroform. The filtrate is completely dried again. Thereafter, an appropriate amount is dissolved in HF and determined by gel permeation chromatography (hereinafter simply abbreviated as GPC).

In the present invention, the molecular weight by GPC chromatography is measured under the following conditions. That is, the column was stabilized in a heat chamber at 40°C, and TH of the resin was adjusted to a sample concentration of 0.3% by weight by flowing TH as a solvent through the column at this temperature at a flow rate of 1 ml per minute.
200 μQ of F sample solution 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 created using several types of monodisperse polystyrene standards. As a standard polystyrene sample for creating a calibration curve, for example, Press
manufactured by ureChemical Co., or manufactured by Toyo Tsudani Gyo Co., Ltd., with a molecular weight of 6 x 10", 2.I x 10'
, 4X103.1.75 X 10', 5, I X 1
0', 1. lX105.3.9X10', 8.6X
It is appropriate to use a 10', 2 x 10r'', 4.48 x 10' standard polystyrene sample with at least 10 points.In addition, an RI (refractive index) is used for the detector. As a column, it is best to combine multiple commercially available polystyrene gel columns, for example, W
μmstyrage1500.103 manufactured by aters
．． A combination of 104.10s and 5ho manufactured by Showa Denko
dex KF-80M, KF-802, 803, 80
4,805 combination or TSK manufactured by Toyo Soda Co., Ltd.
gel G100H, G2000H, G2500H, G
3000H, G4000H, G5000H, G6000
)1. A combination of G7000H and GMH is preferred.

Further, the toner of the present invention has a glass transition temperature of 50 to 70°C. When the glass transition temperature is within this range, blocking resistance and fixing properties will be good. If the glass transition temperature is less than 50°C, the blocking resistance will be reduced, and if it is higher than 70°C, the fixing property will be insufficient.

Note that the glass transition temperature referred to here is determined by differential scanning calorimetry. This measurement is performed using the commonly known AST
It is carried out in accordance with MD3418-82.

That is, the temperature is raised to 120 °C or higher at a temperature increase rate of 10 °C/win, 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. The glass transition temperature (Tg) is defined as the intersection of the midline of the baseline and the knitting line.

The binder resin used in the toner of the present invention includes:
Specific examples of monomers used include those obtained by polymerizing one or more monomers selected from styrenes, acrylic acids, methacrylic acids, and their derivatives, from the viewpoint of developing characteristics and charging characteristics. Examples include:

Styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene; acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n-acrylate Acrylic acid and its esters such as tetradecyl, n-hexadecyl acrylate, lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate; methacrylic acid, methyl methacrylate.

Ethyl methacrylate, propyl methacrylate, butyl methacrylate, amyl methacrylate, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, phenyl methacrylate , methacrylic acid and its esters such as 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, dimethylaminoethyl methacrylate, glycidyl methacrylate, and stearyl methacrylate.

In the toner of the present invention, in addition to the above-mentioned heptamers, a small amount of other heptamers such as acrylonitrile, 2-vinylpyridine, and
-vinyl pyridine, vinyl carbazole, vinyl methyl ether, butadiene, isoprene, maleic anhydride,
Maleic acid, maleic monoesters, maleic diesters, vinyl acetate, and the like can also be used.

Further, as the crosslinking agent used in the toner of the present invention, divinylbenzene, bis(
4-acryloxypolyethoxyphenyl)propane, ethylene glycol diacrylate, l,3-butylene glycol diacrylate, 1,4-butadiol diacrylate, l,5-bentanediol diacrylate,
1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol #200. Examples include diacrylates #400 and #600, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester diacrylate (trade name: ANDA; manufactured by Nippon Kayaku Co., Ltd.), and those in which the above acrylates are replaced with methacrylates. .

In addition, examples of polyfunctional crosslinking agents include pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis(4-methacryloxy), (polyethoxyphenyl)propane, diallyl phthalate, triallyl cyanurate, triallyl isocyanurate, triallyl trimellitate, diaryl chlorendate, and the like.

Charge control agents used in the toner of the present invention include nigrosine dyes, quaternary ammonium salts, basic dyes, amino acid-containing polymers, etc., which impart positive polarity to the toner, and which impart negative polarity. Examples of such dyes include chromium-containing monoazo dyes, chlorine-containing organic dyes, and metal salts of salicylic acid derivatives, but are not limited to these.

Further, as the colorant used in the toner of the present invention, all pigments and dyes conventionally used as colorants for toners can be used. Specifically, carbon black, lamp black, and iron black.

Ultramarine blue, nigrosine dye, aniline blue, calco oil blue, DuPont oil red, quinoline yellow, methylene blue chloride, phthalocyanine blue, phthalocyanine green, Hansa yellow G, rhodamine 6C
Examples include lake, chrome yellow quinacridone, benzidine yellow, malachite green, malachite green hexalate, oil black, azo oil black, rose bengal, monoazo dyes and pigments, disazo dyes and pigments, trisazo dyes and pigments, and mixtures thereof.

In addition to the above-mentioned binder resin, charge control agent, and colorant, the toner of the present invention may contain various plasticizers (phthalate) for the purpose of adjusting the thermal properties, electrical properties, physical properties, etc. of the toner. It is also possible to add auxiliary agents such as dibutyl acid, dioctyl phthalate, etc.), resistance modifiers (tin oxide, lead oxide, antimony oxide, etc.). Furthermore, in the present invention,
After producing the toner particles (5-20.), Tie,
Fine powders such as Al2O, Sin, etc. are added to coat the toner particle surface to improve the fluidity of the toner, and zinc stearate, phthalic acid, etc. are added to prevent deterioration of the photoreceptor. You can also try to

The toner of the present invention is particularly useful for image formation using a one-component development method in electrophotography, and the image forming method of the present invention will be described next.

The image forming method of the present invention is an image forming method using a component development method in electrophotography in which a thin layer of toner is supplied to a latent image carrier to develop a latent image, and the image forming method has the above-described specific composition and physical properties. It is characterized by using toner. Note that toner thinning is usually achieved by including a toner conveying member, a toner layer thickness regulating member, and a toner supplying member, and in which the toner supplying member and toner conveying member and the toner layer thickness regulating member and toner conveying member are in contact with each other. It is carried out using the same equipment.

The image forming method of the present invention will be explained in more detail with reference to the drawings.

The drawing is a schematic cross-sectional view of an example of a developing device using a non-magnetic-component toner useful in carrying out the method of the present invention. In the drawing, the toner 6 of the present invention contained in a toner tank 7 is forcibly brought to a toner supply member (sponge roller) 4 by a stirring blade (toner supply auxiliary member) 5. Supplied. and,
As the toner supply member 4 rotates in the direction of the arrow, the toner taken into the toner supply member 4 is transported to the toner conveyance member 2, where it is rubbed and electrostatically or physically adsorbed, and the toner conveyance member 2 It rotates strongly in the direction of the arrow, and a uniform thin layer of toner is formed by the steel toner layer thickness regulating member (elastic blade) 3, and is charged by friction. Thereafter, the toner is transported to the surface of the electrostatic latent image carrier 1 that is in contact with or in close proximity to the toner transport member 2, and the latent image is developed. The electrostatic latent image is created by applying a negative DC charge of 800 V to the organic photoreceptor and then exposing it to light to form a latent image and developing it. In addition,
Developing devices suitable for the toner of the present invention are not limited to those described above.

The image forming method using one-component development method in electrophotography is a preferred method in response to the recent demand for maintenance-free operation, but it is a method in which variations in the physical properties of the toner greatly affect the ability to form a thin layer. In addition, the recent demands for smaller, lighter weight, faster speeds, etc. of devices have led to increasingly demanding and high performance demands on toner.

However, since the toner of the present invention has excellent fixing properties, anti-offset properties, and anti-blocking properties, and does not film on the developing roller, high-quality images can be obtained by the method of the present invention.

〔Example〕

Hereinafter, the present invention will be explained in more detail with reference to Examples. Note that both parts and percentages are based on weight.

Example 1 Styrene/methyl acrylate copolymer 55 parts Polyester resin 40 parts Device molecular weight Polypropylene 5 parts Salicylic acid derivative zinc salt 4 parts Carbon black
8 parts A mixture having the above composition is melt-kneaded using a hot roll mill, cooled, and then ground using a hammer mill, and then pulverized using an air jet type pulverizer. The obtained finely pulverized product was classified to have an average particle size of 11. And so.

To 100 parts of the present particles, 0.2 parts of Sin and fine powder were added and mixed to obtain a toner.

When the TI (F insoluble content) of the obtained toner was measured, it was 1
It was 3.6%. In addition, when we measured the molecular weight distribution of the THF soluble component, it was approximately 27,000 on the GPC chart.

It had a peak at about 98,000 and about 1,100,000 positions.

Further, the glass non-transition temperature (Tg) of the toner was measured and found to be 65°C.

When the obtained toner was used to form an image using a developing device as shown in the drawing, a good image was obtained and the fixability was also good. The image remained good even after 10,000 sheets were continuously printed, with no difference from the initial image.

Furthermore, no blocking occurred within the developing device, and no filming occurred on the developing roller.

(Development is reversal development, and the charging part of the photoreceptor is -800V.
, the exposure area is -100V, and toner is developed in the exposure area. ) Comparative Example 1 A toner was produced in the same manner as in Example 1, except that polystyrene was used instead of the styrene/methyl acrylate copolymer in Example 1.

When the THF-insoluble content of the obtained toner was measured, it was found to be 11
．． It was 2%. In addition, when we measured the molecular weight of the THF soluble component, the GPC chart showed that it was approximately 25,000, which was approximately 80,000.
．． 70,000, with a peak at approximately 1,080,000. Further, when the Tg of the toner was measured, it was 78° C., indicating that this toner had insufficient fixing properties.

Example 2 Styrene-methyl acrylate copolymer 60 parts Polyester resin 35 parts Low molecular weight polypropylene 5 parts Salicylic acid derivative zinc salt 4 parts Carbon black
8 parts A mixture having the above composition was treated in the same manner as in Example 1 to obtain particles with an average particle size of 12 pa. This particle 100
0.2 part of Tie2 fine powder was added and mixed to prepare a toner.

The T-insoluble content of the obtained toner was measured.

It was 14.1%. In addition, when we measured the molecular weight distribution of TI (F soluble component), it was found that it was approximately 2.6 on the GPC chart.
Ten thousand.

It had a peak or shoulder at approximately 87,000 and approximately 1,120,000 positions. Furthermore, the Tg of the toner was measured and found to be 68°C.

When this toner was inserted into the same developing device as in Example 1 and an image was produced under the same conditions, a clear image was obtained, and even after continuous printing of 10,000 sheets, there was no difference from the initial image and the image was good. .

Furthermore, no toner fusion occurred on the developing roller (sleeve), and no toner blocking occurred within the developing device. Further, no streaks or the like were observed on the image.

Comparative Example 2 Low molecular weight polypropylene 5 parts Salicylic acid derivative zinc salt 3 parts Carbon black 10 parts A mixture having the above composition was treated in the same manner as in Example 1 to obtain particles with an average particle size of 11-.

A toner was prepared by adding and mixing 0.5 parts of SiO□ fine powder to 100 parts of the present particles.

When the THF soluble content of the obtained toner was measured, it was approximately 4.
．． No peaks or shoulders were observed except for a peak at 50,000. Further, when the THF-insoluble content was measured, it was 18.8%. Further, when the Tg of the toner was measured, the temperature was 54° C. When continuous printing was performed using 0 toner, toner fusion to the developing roller occurred, and toner blocking occurred within the developing device.

Comparative Example 3 Styrene-methyl acrylate copolymer 90 parts Polyester resin 5 parts Low molecular weight polypropylene 5 parts Salicylic acid derivative zinc salt 4 parts Carbon black
8 parts A mixture having the above composition was treated in the same manner as in Example 1 to prepare a toner. Regarding the obtained toner,
The content insoluble in THE was measured and found to be 26.3%.

Also.

When the THF soluble content was measured, it was approximately 28,000, approximately 8.0
Ten thousand.

It had a peak at a position of approximately 1.02 million. Furthermore, when the Tg of the toner was measured, it was 69° C., indicating that this toner had insufficient fixing properties.

The results of the above Examples and Comparative Examples are summarized as shown in Table 1 and Table 2.

Table-1 Table-2 [Effects of the invention]- The toner for developing electrostatic images of claim (1) has a TH of the toner.
The content of F-insoluble matter is 20% by weight or less, and the molecular weight distribution of the THF-soluble matter of the toner measured by GPC has at least one peak in the region of molecular weight less than 30,000.
The toner has at least one peak or shoulder in the molecular weight range of 30,000 to 1,000,000, and has at least one peak or shoulder in the molecular weight range of over 1,000,000, and the toner has a glass transition temperature of 50 to 70. ℃, it has excellent fixing properties, anti-offset properties, and anti-blocking properties, and does not form a film on the developing roller.

Therefore, by the image forming method of claim (2), high quality images can be stably obtained over a long period of time.

[Brief explanation of drawings]

The drawing is a schematic sectional view showing an example of a developing device using the non-magnetic component toner of the present invention useful for carrying out the method of the present invention. 1... Electrostatic latent image carrier, 2... Toner transport member, 3
... Toner layer thickness regulating member, 4... Toner supply member, 5
... Stirring blade, 6... Toner, 7... Toner tank.

Claims (2)

[Claims] (1) In a toner consisting of at least a binder resin, a charge control agent, and a colorant, the content of tetrahydrofuran-insoluble components in the toner is 20% by weight or less, and the content of tetrahydrofuran-soluble components in the toner is determined by gel permeation chromatography. In the molecular weight distribution, there is at least one peak in the region of molecular weight less than 30,000, and the molecular weight is 30,000 to 100,000.
The toner has at least one peak or shoulder in the molecular weight range of 0,000,000, and at least one peak or shoulder in the molecular weight range of more than 1,000,000, and the toner has a glass transition temperature of 50 to 70°C. Toner for developing electrostatic images. (2) An image forming method using a one-component development method in electrophotography, in which a thin layer of toner is supplied to a latent image carrier to develop a latent image, characterized by using the toner according to claim (1). image forming method.