JP2003029462A - Toner, image forming method and image forming apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide toner where there is no occurrence of ozone odor and toner soiling of a contact electrifying roller is small in an image forming method using a contact electrifying method. SOLUTION: In the toner used for the image forming method provided with an electrifying process electrifying by a contact electrifying mean with the surface of 20 to 60 MΩ, it is characteristic that at least one peak is provided in the value of molecular weight distribution by GPC acquired from soluble portion of THF of the toner (mainly binding resin) that is from 100 to 10,000 and half-value width of the distribution has molecular weight that is <=15,000.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner for developing an electrostatic charge image formed by electrophotography, electrostatic recording or the like, an image forming method using the toner, and an image forming apparatus.

[0002]

2. Description of the Related Art Conventionally, as an electrophotographic method, U.S. Pat. No. 2,297,691 and JP-B-42-23910 are known.
Although many methods are known, such as Japanese Patent Publication No. 43-24748 and Japanese Patent Publication No. 43-24748, generally, a photoconductive substance is used,
An electric latent image is formed on the photoconductor by various means, then the latent image is developed with a developer, and if necessary, the developer image is transferred to a transfer material such as paper, followed by heating and pressure. It is fixed by heating under pressure, solvent vapor or the like to obtain a copy. Further, when there is a step of transferring the developer image, a step for removing the residual developer is usually provided.

A developing method for visualizing an electric latent image by using a developer is, for example, a magnetic brush method described in US Pat. No. 2,874,063, and a magnetic brush method of 2,618,55.
No. 2, No. 2,221,776, powder cloud method, US Pat. No. 3,909,258, conductive powder method. A method using a magnetic toner is known.

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

Nowadays, such a recording method has been widely used not only for general copying machines but also for computer output and microfilm printing. Therefore, the required performance has become higher, and various performances such as smaller size, lighter weight, lower energy, more maintenance-free, and more personal have been simultaneously demanded. In order to satisfy these requirements, the demands on the toner have become more severe in various aspects.

For example, as described above, the range of application is widened,
When used in general offices and homes, it is necessary to pay attention not only to the safety of the toner as a substance but also to the odor generated during fixing. Further, copiers, printers, etc. are often equipped with a filter for deodorization, that is, for adsorbing odors, ozone, etc., but this is also disadvantageous in terms of production cost, and it is also necessary to maintain deodorization performance. To do so, there is also the trouble of regular replacement.

[0007] In particular, the generation of ozone due to corona charging is not preferable, and a general user tends to make it uncomfortable. However, since the contact charging method can directly give an electric charge to the photoconductor, it has excellent power consumption efficiency, and it has many advantages such as almost no generation of ozone. There is a problem that a so-called cleaning blade slipping toner is likely to accumulate on the charging roller, resulting in poor charging of the photoreceptor.

For example, in Japanese Patent No. 2814211, the content of benzaldehyde in the toner is 0.005% by weight or less, the ratio of Mw to Mn (Mw / Mn) in the binder resin is 5 or more, and the molecular weight is 10 in the contact charging means. It is stipulated that the content of 1,000 or less components is contained in an amount of 10 to 50% by weight, but this also has not been enough to suppress the contamination of the charging roller. Further, this problem is more remarkable as the particle size of the toner becomes smaller in recent years, and therefore, the present situation is that no proposal has been found to improve this problem.

[0009]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a toner, an image forming method and an image forming apparatus which can improve the above-mentioned drawbacks, can deal with the problem of odor, and have less toner contamination on a contact charging roller. To provide. Further, another object of the present invention is to provide a toner, an image forming method and an image forming apparatus which simultaneously satisfy the above-mentioned odor and excellent performance in other characteristics.

[0010]

In order to solve the above problems, the present invention provides a toner (mainly a binder resin) of THF as a toner used in an image forming method having a charging step of charging by a contact charging means. The value of the molecular weight distribution by GPC determined by the soluble component has at least one peak between 1000 and 10000, and the half-width of the distribution has a molecular weight of 1
It is characterized in that the use of toner of 5,000 or less is adopted as a main technical means. By adjusting the molecular weight distribution of the toner as described above, the toner contamination on the charging roller due to the electrostatic adhesion to the charging roller due to fusing or electrostatic adhesion is improved. Half-width is molecular weight 1
If it exceeds 5,000, the toner contamination on the charging roller due to electrostatic adhesion may be aggravated, probably because the charge amount distribution tends to be broad. That is, the toner contamination on the charging roller can be prevented by combining both the charge injection reduction due to the contact charging roller surface resistance and the electrostatic adhesion improvement due to the toner molecular weight half-value width. The most important point of the present invention is that the proper contact charging roller surface resistance is 20 to 160M.
Ω and proper toner (binder resin) molecular weight distribution are combined,

According to the present invention, a great effect can be achieved by using the toner and the image forming method using the contact charging means having the surface resistance of 20 to 160 MΩ, for example, the contact charging roller. In this case, although the detailed mechanism is not yet sufficient, the lower the surface resistance of the charging roller surface, the more advantageous it is for toner contamination. It is considered that this is because charge injection (counter charge) that occurs when the toner passing through the cleaning blade comes into contact with the charging roller does not easily occur, and electrostatic adhesion is suppressed. However, if the surface resistance is too low, it is difficult to apply uniform contact charging to the photoconductor, and charging failure tends to occur.

In the toner of the present invention, particles of 5 μm or less are 2
0 to 80% by number, weight average particle diameter of 6.0 to 10.5 μm
By doing so, the toner contamination on the charging roller is further improved. Within the above range, the attachment of the additive to the toner base is likely to be uniform, and the excess additive is less likely to be released from the toner base. This is because contamination of the charging roller due to the additive is improved.

Next, the measurement of toner particle size will be described. The toner particle size distribution can be measured by various methods, but in the present invention, it was measured using a Coulter counter. That is,
A Coulter Counter TA-II type (manufactured by Coulter) is used as a measuring device, an interface (manufactured by Nikkaki) for outputting number distribution and volume distribution and a PC9801 personal computer (manufactured by NEC) are connected, and an electrolyte is 1
Prepare a 1% aqueous NaCl solution using graded sodium chloride.

As a measuring method, the electrolytic aqueous solution 10 to 1 is used.
A surfactant, preferably 0.1 to 5 ml of alkylbenzene sulfonate is added to 5 ml as a dispersant, and 2 to 20 mg of a measurement sample is further added thereto.
Performs dispersion processing. Electrolyte 100 in another beaker
~ 200 ml, to which the sample dispersion liquid was added so as to have a predetermined concentration, and a particle size distribution of particles of 2 to 40 µm based on the number was used by using the Coulter Counter TA-II type with an aperture of 100 µm. The volume distribution and the number distribution of the particles of 2 to 40 μm were measured, and the weight-based weight average particle diameter (D4: the median value of each channel was used as the representative value of the channels) determined from the volume distribution was determined.

The surface resistance of the charging roller can be measured, for example, with a resistivity meter Hiresta IPHCP-HT260 manufactured by Mitsubishi Petrochemical at an applied voltage of DC-500v. Here, the material of the charging roller is not particularly limited.

The toner of the present invention has a Tg value of 57-6.
By setting the temperature to 5 ° C, the contamination of the charging roller is further improved. Within this range, storability due to toner fusion is maintained. It is desirable to find Tg by a general DSC.

Further, in the toner of the present invention, the weight% of the molecular weight distribution of 10 ⁵ or more by gel permeation chromatography (GPC) determined by the THF-soluble content (hereinafter referred to as gel content) is 20% or less. By doing so, adhesion to the charging roller is reduced and it is effective for toner contamination. If it exceeds 20%, the distribution of the charge amount tends to be non-uniform, and electrostatic adhesion to the charging roller tends to occur, which is not preferable.

The GPC is measured as follows.
Stabilize the column in a 40 ° C. heat chamber and add 1 ml / min of THF as solvent to the column at this temperature.
At a flow rate of 0.05 to 0.6% by weight as a sample concentration
50-200 μl of a THF sample solution of the resin prepared in 1 above is injected and measured. In measuring the molecular weight of the sample (toner), the molecular weight distribution of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared using several kinds of monodisperse polystyrene standard samples and the count number. As a standard polystyrene sample for preparing a calibration curve, for example, Pressure Che
medical Co. Alternatively, the molecular weight of Toyo Soda Kogyo Co., Ltd. is 6 × 10 ² , 2.1 × 10 ³ , 4 × 10 ³ , 1.75.
× 10 ⁴ , 5.1 × 10 ⁴ , 1.1 × 10 ⁵ , 3.9 × 1
It is suitable to use those of 0 ⁵ , 8.6 × 10 ⁵ , 2 × 10 ⁶ , and 4.48 × 10 ⁶ , and to use at least about 10 standard polystyrene samples. An RI (refractive index) detector is used as the detector.

The method for measuring the THF-soluble component is as follows. The gel content is 80 after pressing the resin at 150 ° C.
It is determined by putting it in a metal basket of mesh, immersing it in toluene for 24 hours, drying it, and then measuring and calculating the weight of the insoluble matter. Further, the number average molecular weight and the weight average molecular weight are determined by the GPC method. As a measurement condition, GP
C device: HLC-802A, manufactured by Tosoh Corporation, detector: RI, column: GMH × 6, manufactured by Tosoh Corporation, solvent: tetrahydrofuran, flow rate: 1.0 ml / min,
Sample: 0.5% tetrahydrofuran solution, column temperature:
38 ° C was adopted. Regarding the molecular weight distribution of the sample,
The molecular weight of the sample was calculated from the relationship between the logarithmic value of the calibration curve prepared with several kinds of monodisperse polystyrene standard samples and the count number.

The binder resin in the toner used in the present invention is a styrene resin, which is obtained by polymerizing styrene and one or more kinds of monomers selected from styrenes, acrylic acids, methacrylic acids and their derivatives. It is preferable from the viewpoint of development characteristics and charging characteristics. Examples of monomers that can be used include styrenes such as styrene, α-methylstyrene, vinyltoluene, and chlorostyrene. Acrylic acids, methacrylic acids and their derivatives include acrylic acid, methyl acrylate, ethyl acrylate, propyl acrylate, butyl acrylate, octyl acrylate, 2-ethylhexyl acrylate, n-tetradecyl acrylate, n-acrylic acid. Hexadecyl,
Acrylic acid esters such as lauryl acrylate, cyclohexyl acrylate, diethylaminoethyl acrylate, dimethylaminoethyl acrylate, etc. may be mentioned. Similarly, methacrylic acid, methyl methacrylate, ethyl methacrylate, propyl methacrylate, butyl methacrylate, methacrylic acid may be mentioned. Amyl acid, hexyl methacrylate, 2-ethylhexyl methacrylate, octyl methacrylate, decyl methacrylate, dodecyl methacrylate, lauryl methacrylate, cyclohexyl methacrylate, phenyl methacrylate, 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate. Methacrylic acid esters such as dimethylaminoethyl methacrylate, glycidyl methacrylate, and stearyl methacrylate.

In addition to the above-mentioned monomers, a small amount of other monomers within the range in which the object of the present invention can be achieved, such as acrylonitrile, 2-vinylpyridine, 4-vinylpyridine, vinylcarbazole, vinylmethyl ether, butadiene, isoprene, and anhydrous. Maleic acid, maleic acid, maleic acid monoesters, maleic acid diesters, vinyl acetate and the like may be used.

As the cross-linking agent used for forming the binder resin, as a bifunctional cross-linking agent, divinylbenzene, bis (4-acryloxypolyethoxyphenyl) propane,
Ethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butanediol diacrylate, 1,5-pentanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, diethylene glycol diacrylate , Triethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol # 200, # 400, # 600 diacrylate, dipropylene glycol diacrylate, polypropylene glycol diacrylate, polyester type diacrylate (MANDA Nippon Kayaku), And those obtained by changing the above acrylates to methacrylates.

Pentaerythritol triacrylate, trimethylolethane triacrylate, trimethylolpropane triacrylate, tetramethylolmethane tetraacrylate, oligoester acrylate and its methacrylate, 2,2-bis (4-methacryloxy, poly Ethoxyphenyl) propane, diallyl phthalate, triallyl cyanurate,
Examples thereof include triallyl assocyanurate, triallyl isocyanurate, triallyl trimellitate, and diaryl chlorendate.

Polyester Resin Generally, it can be produced by reacting a polyhydric alcohol with a polybasic carboxylic acid or a reactive acid derivative thereof. Examples of the polyhydric alcohol constituting the polyester resin include ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, neopentane glycol, cyclohexanediene. Examples include diols such as methanol, hydrogenated bisphenol A, polyoxyethylenated bisphenol A, bisphenol A alkylene oxide addition compounds such as polyoxypropyleneized bisphenol A, and other dihydric alcohols.

Examples of the polybasic carboxylic acid include malonic acid, succinic acid, adipic acid, sebacic acid, alkylsuccinic acid, maleic acid, fumaric acid, mesaconic acid, citraconic acid, itaconic acid, glutaconic acid, cyclohexanedicarboxylic acid. , Isophthalic acid, terephthalic acid and other 2
Examples thereof include basic carboxylic acids or their reactive acid derivatives such as acid anhydrides, alkyl esters and acid halides.

In addition to these carboxylic acids, in order to make the polymer non-linear to the extent that tetrahydrofuran-insoluble matter is not generated, in addition to the above-mentioned carboxylic acids, a polyhydric alcohol having a valence of 3 or more and / or a polyhydric alcohol having a valence of 3 or more is used. A basic carboxylic acid may be added.

Examples of the trihydric or higher polyhydric alcohol include sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol,
1,2,4-butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,3
5-trimethylolbenzene etc. can be mentioned.

As the polybasic carboxylic acid having a valence of 3 or more,
For example, 1,2,4-butanetricarboxylic acid, 1,2,
4-cyclohexanetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, 2,5,7-naphthalenetricarboxylic acid and the like can be mentioned.

Among these polyester resins, a polycondensate containing aromatic polycarboxylic acid and bisphenol A as main monomer components, for example, terephthalic acid / ethylene oxide adduct of bisphenol A / cyclohexanedimethanol can be obtained. Linear polyester is preferred. In the present invention, at least a styrene resin, an acrylic resin, and a polyester resin are preferable because the desired toner particle size can be easily obtained, and charging can be easily obtained with a sharp distribution.

As the colorant contained in the toner used in the present invention, generally known dyes and pigments can be used. Examples of such dyes and pigments include carbon black, nigrosine dye, lamp black, Sudan Black SM, First Yellow G, Benzidine Yellow, Pigment Yellow, Indo First Orange, Irgadine Red, Paranitroaniline. Red, Toluidine Red, Carmine FB, Permanent Bordeaux FRR, Pigment Orange R, Resor Red 2
G, Rake Red C, Rhodamine FB, Rhodamine B
Lake, Methyl Violet B Lake, Phthalocyanine Blue, Pigment Blue, Brilliant Green B, Phthalocyanine Green, Oil Yellow GG, Zapon First Yellow CGG, Kayaset Y963,
Kayaset YG, Sumiplast Yellow GG, Zapon Fast Orange RR, Oil Scarlet, Sumiplast Orange G, Orazole Brown B, Zapon Fast Scarlet CG, Aizenspiron Red BEH, Oil Pink OP, etc. are applicable. These colorants are preferably added in a proportion of 5 to 20% by weight with respect to the binder resin.

When the toner of the present invention contains a wax, it is preferable to use carnauba wax and / or rice wax and / or ester wax as the wax. Since these have excellent dispersibility in the toner,
The toner does not remain on the fixing roller after fixing, which is highly effective in so-called releasability.

When the toner of the present invention is a magnetic toner, the magnetic fine particles which also have a role as a colorant include a metal composed of a ferromagnetic element such as iron, cobalt, nickel, etc., such as ferrite, magnetite, or the like. Alloys or compounds containing, or alloys that do not contain strong magnetic elements, but become ferromagnetic by proper heat treatment, such as manganese-copper-aluminum or manganese and copper such as manganese-copper-tin. Alloys of the type referred to as Heusler alloys, including chromium dioxide, and the like. The content ratio of the fine powder of the magnetic material is preferably 30 to 150 parts by weight, and more preferably 40 to 100 parts by weight with respect to 100 parts by weight of the binder resin.

The toner of the present invention may contain a charge control agent, and a positive or negative charge control agent is used as the charge control agent. As the positive charge control agent, generally, nigrosine, an azine dye containing an alkyl group having 2 to 16 carbon atoms (Japanese Patent Publication No. 42-1627), and a basic dye (for example, CI Basic Yellow 2 (CI. 41
000), C.I. I. Basic Yellow 3, C.I.
I. Basic Red 1 (C.I. 45160),
C. I. Basic Red 9 (C.I. 4250
0), C.I. I. Basic Violet 1 (C.I.
42535), C.I. I. Basic Violet 3
(C.I. 42555), C.I. I. Basic Vio
let 10 (C.I. 45170), C.I. I. Bas
ic Violet 14 (C.I. 42510),
C. I. Basic Blue 1 (C.I. 4202
5), C.I. I. Basic Blue 3 (C.I. 5
1005), C.I. I. Basic Blue 5 (C.
I. 42140), C.I. I. Basic Blue 7
(C.I. 42595), C.I. I. Basic Blu
e 9 (C.I. 52015), C.I. I. Basic
Blue 24 (C.I. 52030), C.I. I. Ba
sic Blue 25 (C.I. 52025), C.I.
I. Basic Blue 26 (C.I. 4402)
5), C.I. I. Basic Green 1 (C.I.
42040), C.I. I. Basic Green 4
(C.I. 42000) and the like, lake pigments of these basic dyes (as a laker, phosphotungstic acid,
Phosphomolybdic acid, phosphotungsten molybdic acid, tannic acid, lauric acid, gallic acid, ferricyanide,
Ferrocyanide), C.I. I. Sovent Bl
ack 3 (C.I.26150), Hansa Yellow G
(C.I. 11680), C.I. I. Mordant
Black11, C.I. I. Pigment Black
1 etc. are mentioned.

Further, examples thereof include quaternary ammonium salts such as benzolmethyl-hexadecyl ammonium chloride and decyl-trimethyl ammonium chloride, or vinyl resins containing amino groups, polyamide resins such as condensation polymers containing amino groups. Preferred are nigrosine, quaternary ammonium salts, triphenylmethane-based nitrogen-containing compounds, polyamides, and the like.

As a negative charge control agent, Japanese Patent Publication No. 41-20
No. 153, No. 42-27596, and No. 44-6.
Metal complexes of monoazo dyes described in JP-A-397-45, JP-A-45-26478, and JP-A-50-
Nitramic acid and its salts described in JP-A-133338 or C.I. I. Dyes and pigments such as 14645, JP-B-55-42752, JP-B-58-41508, JP-B-58-7384, and JP-B-59-738.
5, metal complexes of salicylic acid, naphthoic acid, dicarboxylic acids such as Zn, Al, Co, Cr and Fe, sulfonated copper phthalocyanine pigments, nitro groups, halogen-introduced styrene oligomers, chlorine. The paraffin etc. can be mentioned. Particularly, from the viewpoint of dispersibility, metal complex salts of monoazo dyes, metal complexes of salicylic acid, alkylsalicylic acid, naphthoic acid, and dicarboxylic acid are preferable.

The addition amount of these charge control agents, while maintaining good triboelectric chargeability as described above, has the adverse effect of reducing the developing power and environmental stability due to contamination of the surface of the developing sleeve by the charge control agent. In order to keep the amount to the minimum, an addition amount of 0.1 to 3 parts by weight is preferable with respect to 100 parts by weight of the binder resin.

An ethylene olefin polymer may be used in the toner as a fixing aid together with a binder resin. Here, what is applied as an ethylene-based olefin homopolymer or ethylene-based olefin copolymer includes polyethylene, polypropylene, ethylene-propylene copolymer,
There are ethylene-vinyl acetate copolymers, ethylene-ethyl acrylate copolymers, ionomers having a polyethylene skeleton, and the like, and the above copolymers contain 50 mol% or more (more preferably 60 mol% or more) of an olefin monomer. Those are preferable.

Further, in the toner of the present invention, any additive commonly used in toner can be used. For example, silicone varnish, various modified silicone varnish, silicone oil,
Various modified silicone oils, silane coupling agents, silane coupling agents having functional groups, Teflon (registered trademark), zinc stearate, lubricants such as polyvinylidene fluoride, polyvinylidene fluoride, cerium oxide, silicon carbide,
Examples thereof include abrasives such as strontium titanate and the like, fluidity imparting agents such as strontium titanate, titanium oxide and aluminum oxide, zinc oxide, antimony oxide and tin oxide, among which silica, titanium oxide and alumina are preferable.
By including these additives, the powder fluidity of the recycled toner and the replenishment toner becomes close to each other, and the stabilization of the toner charge amount in long-term use is further improved. It is more preferable to use hydrophobized titanium oxide fine powder having an average primary particle diameter of 0.01 to 0.2 μm.

It is important that the above additives not only enhance the fluidity of the toner but also do not impair the chargeability. That is, in the present invention, the hydrophobized titanium oxide fine powder has excellent flowability while maintaining the stable charging property of the toner.

Next, the image forming method of the present invention will be described. In the step of developing the electrostatic charge image with the toner, the magnetic brush method, the cascade developing method, the powder cloud method, and the method using a conductive magnetic toner described in US Pat. No. 3,909,258 are used. JP-A-53-31136
There is a method of using a high-resistance magnetic toner described in Japanese Patent Laid-Open Publication No. 2003-242242. It is also suitable for an image forming method using a one-component developer. In the step of transferring the developed image to the transferred member, an electrostatic transfer method such as a corona transfer method or a bias application method to the contact transfer member is used.

Since the charging and / or transfer and / or charge elimination methods using corona discharge from a member not in contact with the photoconductor to the photoconductor involves the generation of ozone, the members directly contacting the photoconductor are used. There is a contact charging method in which a bias is applied through (that is, contact charging means). In such a method, the activated carbon filter, which is often attached to the conventional copying machine / printer, may be removed. In that case, the toner used in the present invention exhibits a remarkable effect. It is a thing.

A blade cleaning method, a fur brush cleaning method or the like is applied to the step of removing the residual toner on the photosensitive layer of the photosensitive member or the insulating layer, and is particularly suitable for the blade cleaning method.

The toner image on the member to be transferred needs to be fixed on the member. As a means for this, a heat fixing means, a flash heat fixing means and the like can be used, but a heat and pressure means is particularly preferable. Some heated roller fixing means are suitable.

[0044]

EXAMPLES The present invention will be specifically described below with reference to examples, but the examples do not limit the present invention. In addition, all the parts and percentages described in the examples are parts by weight and percentages by weight. Table 1 shows an example of polyester production. The toner particle size is measured by a particle size analyzer TA-II manufactured by Coulter Counter, Inc.
It was measured at 00 μm.

Example 1 The composition shown in A of Table 1 was placed in a 4-neck round bottom flask having a capacity of 1 L equipped with a thermometer, a stirrer, a condenser and a nitrogen gas introducing tube, and the flask was heated with a mantle heater. And nitrogen gas was introduced from the nitrogen gas introduction pipe to raise the temperature in a state where the flask was kept in an inert atmosphere, and then 0.05 g of dibutyltin oxide was added to adjust the temperature to 20.
Each polyester was obtained by reacting at 0 ° C. Polyester resin A 100 parts Carnauba wax (Ceralica Noda) 5 parts Carbon black (# 44: Mitsubishi Kasei) 13 parts Orient Chemical S-34 (chromium azo dye) 2 parts

The above materials are sufficiently premixed by a Henschel mixer, melt-kneaded by a single-screw extruder, cooled, coarsely pulverized by a hammer mill to about 1 to 2 nm, and then finely pulverized by an air jet fine pulverizer. Crushed. Further, the finely pulverized product thus obtained was subjected to strict removal of fine powder and coarse powder simultaneously by a multi-division classifier. Next, Nippon Aerosil R-9
72 silica ... 0.5 part by weight was added and mixed by a Henschel mixer to obtain a toner. The toner had a weight average particle diameter of 8.93 μm and a number% of 5 μm or less was 35%. Molecular weight distribution by GPC determined by THF-soluble content of toner (mainly binder resin) Main peak: 800
0, the full width at half maximum of the toner molecular weight distribution is 11,000,
Tg was 61 ° C., and chloroform-insoluble matter was 13%.

When this toner was used as a developer with a ferrite carrier and the triboelectric charge amount was measured, it was −25.3 μC /
It was g. When this toner was packed in a bottle and stored at 50 ° C. for 24 hours, the image (mainly background stain) was evaluated, and a sufficiently satisfactory and clear image was obtained. Using this developer and toner (without storage), imgio45 made by Ricoh
No. 0 remodeling machine was incorporated with a charging roller made of hydrin rubber having a surface resistance of 55 MΩ, and when the image was printed out, the image density was 1.43, which was a sufficient image density. Next, when 300,000 images were printed and the triboelectric charge was measured, -2
Sufficient image density was obtained with 3.2 μC / g and image density of 1.35, without "image density reduction" caused by toner contamination. Further, when the surface of the roller was observed by observing the microscope of the charging roller, adhesion of the toner additive was not recognized. Further, after sampling 10 A3 size black images and evaluating an abnormal image adhering to the non-image portion of the A3 blank paper, no problem was found. Evaluation of toner ozone odor: When 10 panelists arbitrarily selected performed sensory evaluation of ozone odor during continuous copying, no ozone odor could be detected. Toner contamination evaluation: 100 continuously
After the 0th copy, the toner scattering inside the copier, especially around the developing device was observed, but no contamination inside the machine due to the toner scattering was observed.

Comparative Example 1 Images were printed in the same manner as in Example 1 except that a charging roller having a surface resistance of 210 MΩ was used.
Toner contamination occurs on the charging roller after about 7,000 sheets
The image density of the sheet decreased to 0.72, which was not practical.

Comparative Example 2 Images were printed in the same manner as in Example 1 except that a charging roller having a surface resistance of 12 MΩ was used, and the image density was as low as 0.45 from the initial stage, which was not practical. This is because the surface resistance of the charging roller was too low and the charge on the photoconductor was not sufficient.

Comparative Example 3 Using the charging roller (surface resistance 50 MΩ) described in Example 1 and adjusting the polymerization temperature and the polymerization time, the main peak of the molecular weight distribution by GPC: 9000, the half-value width of the toner molecular weight distribution was 18, 000 polyester resins were obtained.
The Tg was 60 ° C and the chloroform-insoluble matter was 11%. The weight average particle size of this toner was 9.1 μm, and the number% of particles having a particle size of 5 μm or less was 32%. When this toner was image-extracted in the same manner as in Example 1, partial charging roller contamination occurred from 10,000 sheets, and the image density was 0.5 in various places on the image.
An extreme decrease of 5 was recognized, which was out of practical use.

Comparative Example 4 Using the charging roller described in Example 1 (surface resistance 80 MΩ), the polymerization temperature and the polymerization time were adjusted, the main peak of the molecular weight distribution by GPC was 7,000, and the half-value width of the toner molecular weight distribution was 20,000. Of polyester resin was obtained. The Tg was 59 ° C. and the chloroform-insoluble matter was 8%. The weight average particle diameter of this toner was 8.8 μm, and the number% of particles having a particle size of 5 μm or less was 40%. When this toner was image-extracted in the same manner as in Example 1, partial charging roller contamination occurred from the 10,000th sheet, and an extremely low image density of 0.65 was observed in places on the image. Became.

Example 2 Styrene / butyrate copolymer resin (polymerization monomer weight ratio 65:35) (weight average molecular weight (Mw) 200,000,
Acid number 20), RA-200H made by Nippon Aerosil
A toner and a developer were obtained in the same manner as in Example 1 except that 1 part by weight was added. GPC molecular weight distribution main peak of this toner: 9000, the toner molecular weight distribution half-width is 1
50,000, Tg 60 ° C, chloroform insoluble matter 11
%Met. The weight average particle diameter of this toner is 9.1 μm,
The number% of particles having a size of 5 μm or less was 32%. This toner is applied to Ricoh's modified imagio450 machine and the surface resistance is 130 MΩ.
When the charging roller made of hydrin rubber of No. 1 was incorporated and the image was printed, the image density was 1.43, which was a sufficient image density. Next, when 300,000 images were printed and the triboelectric charge was measured, it was -28.1 at the start-28.1 μC / g.
It was sufficient at 7.3 μC / g and the image density was also 1.47. Further, there was no image omission caused by toner contamination, and a sufficient image density was obtained. Further, when the surface of the roller was observed by observing the microscope of the charging roller, adhesion of the toner additive was not recognized. In addition, 1 A3 size black image
After sampling 0 sheets, the abnormal image adhering to the non-image portion of the A3 blank paper was evaluated and no problem was found. Evaluation of toner ozone odor: When 10 panelists arbitrarily selected performed sensory evaluation of ozone odor during continuous copying, no ozone odor could be detected. Evaluation of toner contamination: After 1000 continuous copies, toner scattering inside the copying machine, especially around the developing device, was observed, but no contamination inside the machine due to toner scattering was observed.

Example 3 The polyester composition B shown in Table 1 was placed in a 2-liter glass four-necked flask equipped with a thermometer, a stainless steel stirring rod, a glass nitrogen introducing tube, and a downflow condenser. After reacting for 5 hours while stirring at 170 ° C under normal pressure in a mantle heater under normal pressure, the reaction was continued at 210 ° C, and when no change was observed in the value of softening point according to ASTM E28-51T, 1 , 2,
Add to 108 g of 4-benzenetricarboxylic acid anhydride,
Continue the reaction at 210 ° C. to ASTM E28-51
The progress of the reaction is followed from the softening point according to T, and when the softening point reaches a predetermined temperature, the reaction is stopped and cooled to room temperature to obtain a polyester resin, and 3 parts of Carnauba WAX manufactured by CERARICA Noda Co. is used for WAX. A toner was obtained in the same manner as in Example 1 except for the above. The main peak of the molecular weight distribution by GPC of this toner was 8500, the half-value width of the toner molecular weight distribution was 9,000, the Tg was 61.5 ° C., and the chloroform-insoluble content was 13%. The weight average particle size of this toner was 6.4 μm, and the number% of particles having a particle size of 5 μm or less was 70%. When the toner was charged with a hydrin rubber charging roller having a surface resistance of 130 MΩ in a modified machine of imgio450 manufactured by Ricoh and the image was printed, an image density of 1.46 was obtained, which was a sufficient image density. Next, we carried out 300,000 images,
When the triboelectric charge amount was measured, it was −29.1 μC at the start.
/ G was sufficient as −28.3 μC / g, and the image density was also 1.44. In addition, a sufficient image density was obtained without a reduction in image loss caused by toner contamination. No problem was found when visually confirming the charging roller for confirmation. Evaluation of toner ozone odor: When 10 panelists arbitrarily selected performed sensory evaluation of ozone odor during continuous copying, no ozone odor could be detected. Evaluation of toner contamination: After 1000 continuous copies, toner scattering inside the copying machine, especially around the developing device, was observed, but no contamination inside the machine due to toner scattering was observed.

Example 5 The same procedure as in Example 4 was carried out except that a toner having a toner Tg of 55 ° C. was obtained as a polyester by adjusting the monomer formulation described in Example 4, and 300,000 sheets of images were printed. No image loss was observed, and a good image was stably obtained as in Example 1. Evaluation of toner ozone odor: When 10 panelists arbitrarily selected performed sensory evaluation of ozone odor during continuous copying, no ozone odor could be detected. Evaluation of toner contamination: After 1000 continuous copies, toner scattering inside the copying machine, especially around the developing device, was observed, but no contamination inside the machine due to toner scattering was observed.

Example 6 The same procedure as in Example 4 was carried out except that a polyester having a gel content of 0.4% was obtained by adjusting the polymerization time and temperature described in Example 4 to obtain 300,000 sheets of images. As a result, no image loss was observed, and a good image was stably obtained as in Example 1. Evaluation of toner ozone odor: When 10 panelists arbitrarily selected performed sensory evaluation of ozone odor during continuous copying, no ozone odor could be detected. Evaluation of toner contamination: After 1000 continuous copies, toner scattering inside the copying machine, especially around the developing device, was observed, but no contamination inside the machine due to toner scattering was observed.

[0056]

[Table 1]

[0057]

[Table 2]

[0058]

[Table 3]

Table 4 shows the judgment criteria of Table 3.

[Table 4]

[0060]

According to the present invention, it is possible to provide a toner, an image forming method and an image forming apparatus, which does not generate ozone odor and has less toner contamination on a contact charging roller in image formation by a contact charging system. It will be possible.

Front page continuation (51) Int.Cl. ⁷ Identification code FI theme code (reference) G03G 9/08 331 (72) Inventor Hiroto Higuchi 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Co., Ltd. ( 72) Inventor Zhu Bing 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company (72) Inventor Maiko Kondo 1-3-6 Nakamagome, Ota-ku, Tokyo Within Ricoh Company (72) Inventor Kazuhiro Nishido 1-3rd Nakamagome, Ota-ku, Tokyo F-term in Ricoh Co., Ltd. (reference) 2H005 AA01 AA06 AA08 CA04 CA08 CA14 CB07 CB13 EA03 EA05 EA06 EA07 2H200 FA07 FA08 GA43 GA44 HA02 HA28 HB12 HB22 HB46 MB05

Claims (10)

[Claims] 1. The value of the molecular weight distribution by GPC determined by the THF-soluble content of toner (mainly binder resin) is 100.
Having at least one peak between 0 and 10000,
A half-value width of the distribution is 15,000 or less in molecular weight, and a toner used in an image forming method having a charging step of charging by a contact charging means having a surface of 20 to 60 MΩ. 2. The weight% of the molecular weight distribution of GPC determined by the THF-soluble content of the binder resin is 10 ⁵ or more.
Is 20% or less, the toner according to claim 1. 3. 20 to 80% by number of particles of 5 μm or less,
The toner according to claim 1, wherein a particulate toner having a weight average particle diameter of 6.0 to 10.5 μm is used. 4. The toner according to claim 1, wherein Tg of the toner is in the range of 57 to 65 ° C. 5. The toner according to claim 1, wherein the binder resin is at least a styrene resin, an acrylic resin, a polyester resin, or a mixture thereof. 6. The toner according to claim 1, wherein at least one selected from the group consisting of carnauba wax, rice wax and ester wax is used as the wax dispersed in the toner. 7. The toner according to claim 1, which contains at least one kind of inorganic particles selected from the group consisting of silica, titanium oxide and alumina. 8. A charging step of charging with a contact charging means, an electrostatic charge image forming step of forming an electrostatic charge image on the charged photoreceptor.
And a developing step of developing the electrostatic charge image of the photoconductor with a toner containing at least a binder resin and a colorant to form a toner image on the photoconductor, and fixing the toner image on the transfer material by a heat fixing means. An image forming method comprising at least steps, wherein the toner according to any one of claims 1 to 7 is used as the toner. 9. The image forming method according to claim 8, wherein the surface of the contact charging means is 20 to 60 MΩ. 10. A developing method for forming a toner image on a photoreceptor by developing a contact charging means, an electrostatic charge image forming means, and an electrostatic charge image on a photoreceptor with a toner containing at least a binder resin and a colorant. An image forming apparatus having at least a fixing means for fixing a toner image on a transfer material by a heat fixing means, wherein the surface of the contact charging means is 20 to 60M.
An image forming apparatus, which is Ω and has the toner according to any one of claims 1 to 7 mounted thereon.