JPH11249332A - Electrostatic charge image developing toner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent the occurrence of offset and filming at the time of copying and to improve the heat resistance and low temperature fixability and charge stability of a toner by incorporating natural wax and/or Sasol wax having a melting point lower than a specified temperature. SOLUTION: This electrostatic charge image developing toner comprises a resin composition obtained by incorporating natural wax and/or Sasol wax having a melting point of 50 deg.C-120 deg.C, preferably, 70 deg.C-100 deg.C at the time of synthesizing a binder resin, at least polypropylene wax and a colorant. When a styrene copolymer is used for the binder resin, an acid value for holding charge stability is controlled properly to 1-30, preferably, 1-20, more preferably, 3-10 mg KOH/g, by reguating the amount of an unsaturated carboxylic acid such as (meth)- acrylate to be incorporated into the resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner used for developing an electrostatic image formed on a photosensitive member in an image forming apparatus such as a copying machine or a printer.

[0002]

2. Description of the Related Art Conventionally, toners for developing electrostatic images have been produced by a kneading and pulverizing method in which toner components such as a colorant are melt-kneaded in a binder resin, cooled and solidified, and then pulverized and classified. General. As a toner fixing method in an image forming apparatus such as an electrophotographic apparatus, a pressure fixing method, a non-contact heat fixing method such as flash fixing and oven fixing, and a contact heat fixing method such as a heat roll fixing method are employed. . In particular, the contact heat fixing method can be operated at a higher speed than the pressure fixing method, has higher thermal efficiency than the non-contact heat fixing method, can use a relatively low-temperature heat source, and can reduce the size of the apparatus and save energy. This is the most widespread fixing method because it can be achieved.

In recent years, such a contact heating fixing type electrophotographic apparatus has been required to have higher speed and energy saving. Therefore, low-temperature fixing characteristics are required for the toner. If low-temperature fixing is realized, not only energy saving of the electrophotographic apparatus can be achieved, but also warm-up time can be shortened, and more comfortable operability can be obtained.

However, in such a contact heat fixing system, for example, a part of the toner constituting an image is transferred to the surface of the heat roll at the time of fixing by the heat roll fixing system, and this is transferred to the next transfer paper. The occurrence of the offset phenomenon which re-transfers to the image and contaminates the image has been a problem.

As a technique for preventing the offset phenomenon, for example, a technique of adding a polypropylene wax (for example, JP-A-49-65231) and a technique for preventing the offset phenomenon and achieving low-temperature fixing such as carnauba are used. Technology for adding wax (Japanese Unexamined Patent Publication No. Hei 6-186)
No. 782) is known.

On the other hand, in recent years, a copying machine equipped with an automatic document feeder and a double-sided copying machine has become standard as the copying speed by electrophotography has been increased and the function has been increased. When a document is fed by these devices, or in the second copying process of backside copying or multicolor copying, the surface of the copied image is rubbed with a roller at the time of paper feeding, causing problems such as bleeding and dirt on the image. I have. A similar phenomenon is observed when a plurality of copied images are temporarily stored in a copying machine while being superimposed and taken out one by one with a paper feed roller for a second copy.
The image quality is degraded. It is said that toner having such a problem has poor smear property. As a method for improving the smearing property, it is effective to add a polyethylene wax at the time of kneading (for example, see JP-A-4-31).
No. 3762) is known.

However, in order to simultaneously improve various problems such as low-temperature fixing property, offset property and smear property, the above-mentioned low melting point wax such as polypropylene wax, polyethylene wax or natural wax is added at the time of kneading by the kneading / pulverizing method. Then, filming occurs at the time of copying, which causes a new problem that the fluidity and the chargeability of the toner decrease. This is because the combination of a plurality of types of waxes further deteriorates the compatibility between these and the binder resin, so that the wax is easily released, and as a result, the free wax adheres to the photoreceptor and causes filming. It is considered that the low melting point component of the wax is easily exposed on the surface of the toner, so that the fluidity and chargeability of the toner deteriorate.

[0008]

SUMMARY OF THE INVENTION The present invention can prevent the occurrence of offset and filming during copying, and provides an electrostatic charge excellent in heat resistance, low-temperature fixability, smear, fluidity, and charge stability of toner. An object of the present invention is to provide a toner for image development.

[0009]

SUMMARY OF THE INVENTION The present invention provides a resin composition containing at least a natural wax having a melting point of 120 ° C. or less and / or a sasol wax during the synthesis of a binder resin, and an electrostatic charge image comprising at least a polypropylene wax and a colorant. The present invention relates to a developing toner.

Even when a plurality of types of waxes are simultaneously contained in a toner, offset and filming do not occur on a copied image by incorporating a natural wax and / or a sasol wax during the synthesis of a binder resin, Further, it has become possible to provide a toner for developing an electrostatic image, which is excellent in heat resistance, low-temperature fixing property, smear property, fluidity and charge stability.

In the resin composition, the natural wax and / or the sasol wax are dispersed with a small particle size and uniformly through the binder resin, as compared with the conventional production method added at the time of producing the toner.

The natural wax and / or sasol wax used in the present invention has a melting point of 50 to 120 ° C., preferably 70 to 100 ° C.

As the natural wax used in the present invention, any of vegetable wax, animal wax and mineral wax may be used, and as the plant wax, candelilla wax, carnauba wax, wood wax and the like can be used. Beeswax can be used as animal wax, and montan wax can be used as mineral wax.

In the present invention, the natural wax and / or sasol wax is preferably used in an amount of 0.1 to 5 parts by weight, more preferably 0.3 to 5 parts by weight, based on 100 parts by weight of the binder resin.
3 parts by weight are suitable. If the amount of the natural wax and / or the solsol wax is less than this, the low-temperature fixability is insufficient. If the amount is too large, the heat resistance is reduced, filming is liable to occur, and the fluidity of the toner tends to decrease. is there.

The above-mentioned natural wax and / or sasol wax are contained during the synthesis of the binder resin.
As described above, since the binder resin is added and mixed at the time of synthesis, it is uniformly dispersed in the resin composition with a small particle size, and the amount of exposure to the toner surface and the amount of detachment from the toner are reduced. As a result, it is possible to prevent filming at the time of copying due to the release of the wax and a decrease in heat resistance, fluidity, and chargeability of the toner, which have been particularly problematic, and at the same time, use natural wax and / or sasol wax. It is considered that the low-temperature fixing property and the offset prevention property by the polypropylene wax can function effectively.

[0016] As a method of adding the compound during synthesis, a monomer capable of constituting a binder resin (hereinafter, simply referred to as "monomer") is polymerized, and a natural wax and / or sasol wax are added to the polymer solution. Add and mix. Thereafter, the solvent is distilled off from the wax-dispersed polymer solution to obtain a resin composition in which natural wax and / or sasol wax are dispersed in the binder resin.

As the polymerization method, a method conventionally used for preparing a binder resin, for example, a bulk polymerization method, a solution polymerization method, a suspension polymerization method, an emulsion polymerization method or the like can be adopted. The binder resin may be appropriately selected according to the type of the binder resin, its molecular weight, the molecular weight distribution, or the like, or may be employed in combination. As for the polymerization conditions, the same conditions as the conventional polymerization conditions for obtaining a binder resin can be employed.However, in order to achieve a desired binder resin molecular weight, it is necessary to appropriately set a polymerization temperature, a polymerization time, a solvent, and the like. There is. In addition, natural wax and / or
Alternatively, as a method of dispersing the Sasol wax, a small particle size, specifically, an average particle size of 20 μm is used so that the wax does not precipitate.
The method is not particularly limited as long as it can be dispersed at about m or less, preferably 5 μm or less.

If the dispersed particle size of the wax is too large, the effect of the present invention cannot be sufficiently obtained, that is, not only the natural wax and / or sasol wax may be liberated in the subsequent toner production process, but also the toner As the amount of wax exposed on the surface increases, the heat resistance, fluidity, charge stability and the like of the toner decrease.

As another method of adding natural wax and / or sasol wax at the time of synthesizing a binder resin, first, before polymerization of a monomer, wax is added to a monomer solution containing the monomer and mixed. . Thereafter, the monomer is polymerized while dispersing the wax to obtain a wax-dispersed polymer solution, and the solvent is distilled off to obtain a resin composition.

Regarding the polymerization method and polymerization conditions, the same methods and conditions as in the case where the above-mentioned natural wax and / or sasol wax are added after the polymerization of the monomer can be adopted. Regarding the method of dispersing the natural wax and / or sasol wax, the viscosity of the solution to be added is different between the case where the monomer is added before the polymerization and the case where the monomer is added after the polymerization. Since the case where it is added after polymerization is larger than the case where it is added before polymerization, it is necessary to set the mixing speed higher than in the case described above, or to set the mixing time longer, but in any case, wax It is sufficient that the particles can be dispersed with a small particle size without precipitation.

As the binder resin which can be used in the present invention, styrene copolymer resins, polyester resins, epoxy resins and the like which have been conventionally used as binder resins for toners can be used arbitrarily. As described above, natural wax and / or sasol wax are added and mixed at the time of their synthesis, so that they are relatively small in particle diameter and uniformly dispersed in the binder resin, and are used as a resin composition containing wax. .

Examples of the monomer constituting the binder resin include a styrene monomer, an acrylic monomer, a methacrylic monomer, a vinyl monomer, a polycarboxylic acid monomer and a polyhydroxy monomer. Monomer, epoxy monomer,
Examples include polyester-based monomers, and two or more of these monomers may be used in combination.

Among the binder resins described above, styrene copolymer resins are particularly preferable because they can achieve the object of the present invention more effectively. Examples of the styrene monomer constituting the styrene copolymer resin include styrene monomers such as styrene, α-methylstyrene, p-methylstyrene, p-tert-butylstyrene, and p-chlorostyrene. Its derivatives can be used.

The monomers to be copolymerized with the styrene monomer include methyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, methacrylic acid. n-pentyl, isopentyl methacrylate, neopentyl methacrylate, 3-methacrylic acid
(Methyl) butyl, hexyl methacrylate, octyl methacrylate, nonyl methacrylate, decyl methacrylate, undecyl methacrylate and dodecyl methacrylate; alkyl methacrylates; methyl acrylate, n-propyl acrylate, isopropyl acrylate, acrylic N-butyl acrylate, isobutyl acrylate, t-butyl acrylate, n-pentyl acrylate, isopentyl acrylate, neopentyl acrylate, 3- (methyl) butyl acrylate, hexyl acrylate, octyl acrylate, nonyl acrylate, Acrylic alkyl esters such as decyl acrylate, undecyl acrylate and dodecyl acrylate; acrylic acid, methacrylic acid,
Unsaturated carboxylic acids such as itaconic acid and maleic acid; acrylonitrile, maleic acid ester, itaconic acid ester, vinyl chloride, vinyl acetate, vinyl benzoate, vinyl methyl ethyl ketone, vinyl hexyl ketone, vinyl methyl ether, vinyl ethyl ether and vinyl isobutyl ether And the like. Preferred are methacrylic acid alkyl esters (alkyl group having 1 to 17 carbon atoms) and acrylic acid alkyl esters (alkyl group having 1 to 17 carbon atoms).

The binder resin composed of such a monomer has a number average molecular weight distribution of at least 2,000 to 10,000, as measured by gel permeation chromatography in the absence of natural wax and / or sasol wax. 000, more preferably 2.5
00-7000 The weight average molecular weight / number average molecular weight is in the range of 20-90, more preferably 25-80.

When the number average molecular weight is less than 2,000, heat resistance is lowered or offset is liable to occur.
Exceeding the range lowers the fixing strength. The weight average molecular weight /
When the ratio of the number average molecular weight is less than 20, the offset property is lowered, and when it is more than 90, the fixing strength is apt to be deteriorated.

It is desirable to impart an acid value to the above-mentioned binder resin in order to further improve the dispersibility of natural wax and / or sasol wax, polypropylene wax, colorant and the like and to maintain the charge stability. . For example, when a styrene copolymer resin is used as the binder resin, the acid value is controlled by adjusting the amount of an unsaturated carboxylic acid such as (meth) acrylic acid to be contained in the resin composition, and the value is 1 ~ 30KOHmg / g
Preferably, 1-20 KOH mg / g, more preferably,
3-10 KOH mg / g is suitable.

The most preferred resin composition of the present invention is produced in the following manner. First, a monomer is polymerized to obtain a low molecular weight polymer solution. On the other hand, in a separate container, a natural solution containing natural wax and / or
Or after adding, mixing and dispersing Sasol wax,
Polymerize to prepare a high molecular weight polymer solution. Thereafter, the natural wax and / or solsol wax-dispersed high molecular weight polymer solution and the low molecular weight polymer solution are mixed, stirred to disperse the wax again, and the solvent is distilled off. Thus, a resin composition having a small particle size and being uniformly dispersed can be obtained.

Further, a preferred resin composition in the present invention is produced as follows. First, a natural wax and / or sasol wax are added to a monomer solution containing a monomer, mixed and dispersed, and then the monomer is polymerized to prepare a wax-dispersed low molecular weight polymer solution. On the other hand, the same type of monomer is polymerized in another container to prepare a high molecular weight polymer solution. Thereafter, the low-molecular-weight polymer solution and the high-molecular-weight polymer solution dispersed with these natural waxes and / or sasol wax are mixed and stirred to disperse the wax again, and the solvent is distilled off. Thus, a resin composition having a small particle size and being uniformly dispersed can be obtained.

The natural wax and / or sasol wax may be added during the polymerization, not at the start of the polymerization of the monomer.

The resin composition obtained as described above is
It is subjected to a conventional kneading and pulverizing method together with at least a polypropylene wax and a colorant. In addition, a natural wax and / or a solsol wax and a polypropylene wax are included during the synthesis of the binder resin,
It is not preferable that the compound is present in the resin composition because the effect of preventing offset is insufficient.

The polypropylene wax used in the present invention has a melting point of 125 to 155 ° C., preferably 135 to 155 ° C.
A temperature of 0 ° C, more preferably 140 to 155 ° C, is suitable. When the melting point is lower than 125 ° C., not only the heat resistance is lowered, but also filming is easily generated. On the other hand, 155
If the temperature is higher than ℃, the offset property decreases.

The total amount of the natural wax and / or sasol wax and the polypropylene wax described below is suitably 2 to 10 parts by weight, more preferably 3 to 8 parts by weight, per 100 parts by weight of the binder resin. If the total amount is less than 2 parts by weight, the offset and smear properties will be reduced. If the total amount is too large, the fluidity of the toner will be poor and filming will easily occur. Here, 100 parts by weight of the binder resin means the weight of only the binder resin present in the resin composition.

Among them, the addition weight ratio of the polypropylene wax to the natural wax and / or the sasol wax is from 10: 1 to 1:10, preferably from 10: 1 to 1:10.
1: 2, more preferably 10: 1 to 1: 1.2 is suitable. If the added weight ratio of the natural wax and / or sasol wax is less than this, low-temperature fixability tends to decrease and smear tends to occur, and if it is too large, heat resistance, fluidity and offset properties tend to decrease.

The colorant used in the present invention is not particularly limited, and a colorant conventionally used in electrophotography can be used.

As the black pigment, carbon black, copper oxide, manganese dioxide, aniline black, activated carbon, ferrite, magnetite and the like can be used.

Examples of the yellow pigments include graphite, zinc yellow, cadmium yellow, yellow iron oxide, mineral fast yellow, nickel titanium yellow, navels yellow, naphthol yellow S, banza yellow G, banza yellow 10G, benzidine yellow G, and benzidine. Yellow GR, quinoline yellow lake, permanent yellow NCG, tartrazine lake, and the like can be used.

Examples of the red pigment include red lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indaslen brilliant orange RK, benzidine orange G, indaslen brilliant orange GK, bengala, cadmium red, red lead, permanent Red 4R, Risor Red,
Pyrazolone red, watching red, lake red C, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake B, alizarin lake,
Brilliant Carmine 3B, permanent orange GT
R, Vulcan Fast Orange GG, Permanent Red F4RH, Permanent Carmine FB and the like can be used.

Blue pigments include navy blue, cobalt blue, alkaline blue lake, Victoria blue lake,
Phthalocyanine blue or the like can be used.

The amount of the coloring agent to be added is not particularly limited, but is usually 1 to 20 parts by weight, preferably 3 to 15 parts by weight, per 100 parts by weight of the binder resin.

The toner of the present invention may contain other additives, and may appropriately contain a charge controlling agent, magnetic powder and the like.

As the charge control agent, a positive charge control agent can be used when the positive charge control of the toner is desired, and a negative charge control agent can be used when the negative charge control of the toner is desired. Examples of the positive charge control agent that can be used in the present invention include a nigrosine dye, a triphenylmethane compound, a quaternary ammonium salt compound, and the like. Examples of triphenylmethane compounds include, for example, JP-A-51-11455, JP-A-59-100457, and JP-A-61-12495.
Compounds described in, for example, Japanese Patent Publication No. 5 can be used. As the quaternary ammonium salt compound, for example, compounds described in JP-A-4-70849 or the like can be used. Salicylic acid metal complex as a negative charge control agent,
Examples include gold-containing azo dyes, calixarene compounds, and boron-containing compounds. The charge control agent may be used alone or
Although it is possible to mix and use more than one kind, it is preferable to add 0.5 to 10 parts by weight based on 100 parts by weight of the binder resin.

As the magnetic powder, ferrite, magnetite and iron powder can be used alone or in combination. The inclusion of the magnetic powder can more effectively prevent filming, scattering of toner due to magnetic force, and erosion.

The BET specific surface area is from ² to 15 m ² in order to prevent a decrease in chargeability due to poor dispersion of the magnetic powder in the toner.
/ G, preferably 5 to 12 m ² / g.

The amount of the magnetic powder used in the present invention is 0.5 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the binder resin. If the amount is more than 20 parts by weight, the image density is reduced due to a decrease in developability.

The toner for developing an electrostatic image of the present invention can be easily produced by a known kneading and pulverizing method. At least natural wax produced as described above and / or
Alternatively, a mixture comprising a resin composition containing sasol wax, a colorant, a polypropylene wax, and other additives is kneaded by a kneading extruder, and after the kneaded product is cooled and solidified, pulverized and classified, and the average particle size is 5 to 14 μm. , Preferably 6-1
It is obtained by obtaining toner particles of 2 μm and adding a fluidizing agent and a cleaning aid to the particles as required. In the pulverizing step, the material may be roughly pulverized to 2 mm or less by a pulverizer such as a feather mill, and then finely pulverized to a desired particle size by a mechanical pulverizer.

[0047] The optional fluidizing agent includes
Silica fine particles, titanium dioxide fine particles, amylna fine particles,
Magnesium fluoride fine particles, silicon carbide fine particles, boron carbide fine particles, titanium carbide fine particles, zirconium carbide fine particles, boron nitride fine particles, titanium nitride fine particles, zirconium nitride fine particles, magnetite fine particles, molybdenum disulfide fine particles, aluminum stearate fine particles, magnesium stearate fine particles And zinc stearate fine particles.

It is desirable that these fine particles are subjected to a hydrophobizing treatment with a silane coupling agent, a titanium coupling agent, a higher fatty acid, silicone oil or the like before use.

The amount of the fluidizing agent is preferably 0.05 to 5 parts by weight, more preferably 0.1 to 3 parts by weight, based on 100 parts by weight of the toner.

Examples of the cleaning aid include styrene, acrylic, methacrylic, benzoguanamine, silicone, Teflon and the like, which are granulated by a wet polymerization method such as emulsion polymerization, soap-free emulsion polymerization, non-aqueous dispersion polymerization, or a gas phase method. Various organic fine particles such as polyethylene and polypropylene can be used alone or in combination. The amount of addition is usually 0.1 to 100 parts by weight of the binder resin.
It is 01 to 1 part by weight.

The toner for developing an electrostatic image of the present invention obtained as described above is a one-component developer using no carrier,
Although any of the two-component developers used with the carrier can be used, it is preferable to use the two-component developer. As the carrier used with the toner of the present invention, known carriers can be used, for example, iron powder, a carrier composed of magnetic particles such as ferrite, a coated carrier in which the surface of the magnetic particles is coated with a coating agent such as a resin, Alternatively, any of a dispersion type carrier obtained by dispersing a magnetic fine powder in a binder resin can be used.
Such carriers have a volume average particle size of 15 to 10
Those having a thickness of 0 μm, preferably 20 to 80 μm are suitable.

When the toner of the present invention is used as a positively chargeable toner, a preferable carrier is a chargeable toner.
That is, the carrier has a negatively charged resin on the surface.
Examples of such resins include polyester resins, polyolefin resins such as polyethylene, tetrafluoroethylene, vinylidene fluoride, homopolymers of fluorine-containing vinyl monomers, and copolymers with other vinyl monomers. And the like. Particularly preferred is a carrier on which the above-mentioned negatively chargeable resin coating layer is formed, or a carrier obtained by dispersing magnetic fine powder in the above negatively chargeable resin, from the viewpoint of chargeability in combination with the toner of the present invention. .

When the toner of the present invention is used as a negatively chargeable toner, a carrier having a positively chargeable resin on its surface is preferable. Such resins include acrylic resins,
Styrene-acrylic resin, silicone resin and the like can be mentioned.

The present invention will be described in more detail with reference to the following examples.

[0055]

EXAMPLE 1 70 parts by weight of styrene, 14 parts by weight of butyl acrylate, 14 parts by weight of butyl methacrylate, 2 parts by weight of methacrylic acid and 3 parts by weight of a catalyst were continuously dropped into 100 parts by weight of xylene. Polymerization was performed to produce a low molecular weight polymer solution.

On the other hand, 70 parts by weight of styrene, 14 parts by weight of butyl acrylate, 14 parts by weight of butyl methacrylate, and 2 parts by weight of methacrylic acid were polymerized by bulk polymerization at 120 ° C., and then xylene and carnauba wax (melting point: 84 ° C.) 4 parts by weight were added to disperse the wax in the polymer solution. Thereafter, a catalyst was further added to carry out solution polymerization to prepare a high molecular weight polymer solution.

The above-mentioned low molecular weight polymer solution and high molecular weight polymer solution were mixed at a resin content weight ratio of 1: 1 and then stirred to disperse carnauba wax. Thereafter, the organic solvent was distilled off, and the obtained resin was cooled, solidified, and pulverized to obtain a resin composition. The binder resin produced by the same method except that no carnauba wax was added, the number average molecular weight (Mn) was 4000, the weight average molecular weight / number average molecular weight (Mw / Mn) was 68.8, and the softening point was 119.8 ° C. The acid value was 6.5 KOH mg / g.

102 parts by weight of the above resin composition (consisting of 100 parts by weight of binder resin and 2 parts by weight of carnauba wax (converted value)) 4 parts by weight of polypropylene wax (melting point: 145 ° C.) (Viscol 660P, manufactured by Sanyo Chemical Industries, Ltd.) Carbon black (Mogal L, manufactured by Cabot) 10 parts by weight-Nigrosine dye 5.0 parts by weight (Nigrosine base EX, manufactured by Orient Chemical Co.)-Quaternary ammonium salt 0.5 parts by weight (P-53, manufactured by Orient Chemical Co., Ltd.)・ Magnetic powder (MFP-2, manufactured by TDK) 2 parts by weight Henschel mixer (75 liter capacity)
And mixed for 3 minutes at 3000 rpm. This mixture is screw-extruded and kneaded (TEM50: manufactured by Toshiba Machine Co., Ltd.).
After continuous extrusion and kneading under the conditions of a temperature of 120 ° C., a supply amount of 30 kg / hr and a screw rotation speed of 150 rpm, the mixture was rolled with a press roller having a slit interval of 1 mm, and further subjected to forced water cooling on a belt cooler.

This kneaded product was roughly pulverized with a feather mill (2 mm mesh). The coarsely pulverized material is finely pulverized to 11 μm with a mechanical pulverizer (Krypton KTM-O type, manufactured by Kawasaki Heavy Industries, Ltd.), and a jet mill (IDS) equipped with a natural air flow classifier is used.
-2 type, manufactured by Nippon Pneumatic Co., Ltd.), and fine powder was further cut by a rotary rotor classifier (50ATP classifier, manufactured by Hosokawa Micron) to obtain toner particles having a volume average particle diameter of 11 μm. . Hydrophobic silica (Aerosil, R974) as a fluidizing agent for the obtained toner particles
Was added in an amount of 0.15% by weight to obtain a toner.

(Examples 2 to 8 and Comparative Examples 1 to 4) A toner was prepared in the same manner as in Example 1. However, the monomer composition ratio and polymerization conditions when preparing the resin composition are appropriately set, and the Mn, Mw / Mn and softening point of the binder resin when the obtained resin composition does not contain wax, and the resin composition Table 1 shows only the type and amount of wax contained therein and the type and amount of wax added at the time of kneading the toner.

Example 9 A toner was produced in the same manner as in Example 1 except that the resin composition produced by the following method was used.

To 100 parts by weight of xylene, 70 parts by weight of styrene, 14 parts by weight of butyl acrylate, 14 parts by weight of butyl methacrylate, 2 parts by weight of methacrylic acid, and 5 parts by weight of sasol wax (melting point: 104 ° C.) were added. After dispersion, 3 parts by weight of the catalyst was continuously dropped to carry out polymerization to prepare a low molecular weight polymer solution.

On the other hand, 70 parts by weight of styrene, 14 parts by weight of butyl acrylate, 14 parts by weight of butyl methacrylate, and 2 parts by weight of methacrylic acid were polymerized by bulk polymerization at 120 ° C., and xylene and a catalyst were further added thereto for solution polymerization. Was performed to prepare a high molecular weight polymer solution. After mixing the low molecular weight polymer solution and the high molecular weight polymer solution at a resin content weight ratio of 2: 3, the mixture was stirred to disperse the sasol wax.
Thereafter, the organic solvent was distilled off, and the obtained resin was cooled, solidified, and pulverized to obtain a resin composition. In addition, the number average molecular weight (Mn) of the binder resin containing no sasol wax manufactured by the same method is 4700, the weight average molecular weight / number average molecular weight (Mw / Mn) is 87.1, and the softening point is 125.2.
° C, the acid value was 6.5 KOHmg / g. Further, in 102 parts by weight of the resin composition, 100 parts by weight of the binder resin and 2 parts by weight of Sasol wax were used.

Example 10 70 parts by weight of styrene, 14 parts by weight of butyl acrylate, 14 parts by weight of butyl methacrylate, and 2 parts by weight of methacrylic acid were added to 100 parts by weight of xylene, and the mixture was preliminarily dispersed. Polymerization was carried out by continuously dropping 3 parts by weight to produce a low molecular weight product.

On the other hand, 70 parts by weight of styrene, 14 parts by weight of butyl acrylate, 14 parts by weight of butyl methacrylate, and 2 parts by weight of methacrylic acid were polymerized by bulk polymerization at 120 ° C., and xylene and a catalyst were further added thereto to carry out solution polymerization. Was performed to produce a high molecular weight product.

The low molecular weight compound and the high molecular weight compound are used in a ratio of 2 to 3
, And 3 parts by weight of carnauba wax was added and mixed, and the wax was dispersed in the polymer mixed solution. Thereafter, the resin obtained by distilling off the organic solvent was cooled, solidified, and pulverized to obtain a resin composition.

The binder resin containing no carnauba wax in the same production method had Mn of 3100 and Mw / Mn of 46.
3. The softening point was 118.1 ° C.

[0068]

[Table 1]

For convenience, the amount of wax added at the time of synthesizing the resin is a value based on 100 parts by weight of the total weight of the monomers. Alternatively, the value is based on 100 parts by weight of the resin composition prepared in Comparative Example. The amount of the wax added at the time of kneading the toner was expressed as a conversion value based on 100 parts by weight of the binder resin. Since the binder resin in the resin composition used in the present Examples and Comparative Examples is an addition polymerization type polymer,
The total monomer weight and the binder resin weight are equal.

The above Examples 1 to 10 and Comparative Examples 1 to 4
The toner obtained in the above was mixed with a binder-type carrier manufactured as described below in a weight mixing ratio (toner: carrier) of 5:95.
To obtain a developer.

(Manufacture of Binder Type Carrier) Ingredients: parts by weight ・ Polyester resin (manufactured by Kao Corporation: NE-1110) 100 ・ Inorganic magnetic powder (manufactured by TDK: MFP-2) 500 ・ Carbon black (manufactured by Mitsubishi Kasei: MA # 8) 2 The above materials were thoroughly mixed and crushed with a Henschel mixer, and then the cylinder section was 180 ° C.
The mixture was extruded and kneaded using an extrusion kneader set at 0 ° C. The kneaded product was cooled, coarsely pulverized, finely pulverized with a jet mill, and further classified using an air classifier to obtain a magnetic carrier having a volume average particle size of 55 μm.

The developer obtained by mixing with the binder-type carrier was evaluated for the following items.

(1) Smear property A copier (EP4050; manufactured by Minolta Co.) was fixed at a fixing temperature of 15
The image was partially modified to 0 ° C. and copied using the above-mentioned developer. The copy image fixed on the copy paper was rubbed with another unused copy paper, the degree of dirt on the unused copy paper was observed, and ranking was performed as follows.

○: Almost no stain was noticeable.

Δ: Some stains were observed, but there was no practical problem.

X: Stain was observed on all sides of the paper.

(2) Fixing / peeling strength A copier (EP4050; manufactured by Minolta Co.) was fixed at a fixing temperature of 15
The image was partially modified to 0 ° C. and copied using the above-mentioned developer. 1 for eraser (ER-502R; manufactured by Lion)
The sample was rubbed three times with a load of kg / cm ² , and the decrease in image density was measured using a reflection densitometer (RD900 series; manufactured by Macbeth), and the peel strength was determined.

：: The reduction rate of the image density is less than 20% Δ: The reduction rate of the image density is less than 40% ×: The reduction rate of the image density is 40% or more (3) Offset property Modified so that the fixing temperature can be changed. Copy machine (EP40
50; manufactured by Minolta Co., Ltd.), the fixing roller temperature was raised to around 250 ° C., and the following ranking was performed according to the temperature at which offset occurs. ○: No offset occurs at 250 ° C.

Δ: No offset occurs below 250 ° C.

X: Offset occurred below 230 ° C.

(4) Heat Resistance 5 g of the toner was placed in an incubator and stored at 50 ° C. for 24 hours. Thereafter, the measuring container was inverted to observe the degree of drop of the toner, and the toner was ranked as follows.

：: The toner dropped immediately after the reversal.

Δ: The toner dropped after a while after the reversal.

C: Most of the toner did not fall even after the reversal.

(5) Filming A copier (EP4050; manufactured by Minolta) was fixed at a fixing temperature of 15.
After partially remodeling to 0 ° C and using the above developer to continuously copy 50,000 A4 documents with a 6% black and white ratio, a halftone image was formed and the photoreceptor was observed. Was ranked as follows.

：: Neither disturbance of the image nor adhesion of the toner component to the photosensitive member.

Δ: A part of the surface of the photosensitive member is slightly hazy, but there is no image disturbance.

X: The entire photoconductor is cloudy, and the image is further disturbed.

(6) Amount of charge The copier (EP4050; manufactured by Minolta) was fixed at a fixing temperature of 15
Modified partly to 0 ° C, copy A4 original with 6% black and white ratio using the above developer, sample the developer after continuous copying 50,000 sheets from developing unit, and charge toner The amount was measured.

In measuring the charge amount (μC / g), 1 g of the developer weighed by a precision balance is placed evenly on the entire surface of the conductive sleeve 41 of the charge amount measuring device shown in FIG. The rotational speed of the magnet roll 42 provided in the conductive sleeve 41 is set to 100 rpm.
Set to

Then, a bias voltage of 3 kV is applied from the bias power supply 43 to the same polarity as the toner charging potential,
The conductive sleeve 41 is rotated for 0 second, and the potential Vm at the cylindrical electrode 44 at the time when the conductive sleeve 41 is stopped is read.
From No. 1, the weight of the toner attached to the cylindrical electrode 44 was measured with a precision balance, and the average charge amount (μC / g) of each toner was determined.

(7) Underground Fog Using the above-mentioned copying machine, 50,000 A4 originals having a black-and-white ratio of 6% were copied. After continuous copying of 50,000 sheets, a white solid document was copied, and the status of background fog was visually observed and ranked as follows.

○: Fog was hardly noticeable.

Δ: Fog was slightly observed, but there was no practical problem.

X: Fog was observed on the entire surface of the paper.

(8) Image Density Using the above copying machine, 50,000 A4 originals having a black-and-white ratio of 6% were copied. After continuous copying of 50,000 sheets, a solid black original was copied, and the state of image density was visually observed and ranked as follows.

：: ID 1.2 or more Δ: ID 1.0 or more and less than 1.2 ×: ID less than 1.0 The evaluation results are shown in Table 2 below.

[0098]

[Table 2]

In this example, the average particle size of the carrier was measured using a Coulter Multisizer (manufactured by Coulter Inc.).
The measurement was performed using a 0 μm aperture tube. The average particle size of the toner was measured using the same apparatus with a 100 μm aperture tube.

[0100]

According to the present invention, it is possible to prevent smearing and offset during copying, to prevent filming from occurring, and to provide a toner which does not cause a decrease in fluidity or chargeability of the toner.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a charge amount measuring device.

Claims (4)

[Claims] 1. A toner for developing an electrostatic image comprising a resin composition containing at least a natural wax and / or a sasol wax having a melting point of 50 to 120 ° C. at the time of synthesis of a binder resin, and at least a polypropylene wax and a colorant. 2. The toner for developing an electrostatic charge image according to claim 1, wherein the binder resin comprises a styrene-based copolymer and has an acid value of 1 to 30 KOHmg / g. 3. The total addition amount of the natural wax and / or the sasol wax and the polypropylene wax is 2 to 10 parts by weight with respect to 100 parts by weight of the binder resin.
3. The electrostatic image developing toner according to claim 1, wherein the addition weight ratio of the polypropylene wax to the natural wax and / or the sasol wax is 10: 1 to 1:10. 4. The melting point of the polypropylene wax is 125.
The toner for developing an electrostatic charge image according to claim 1, wherein the temperature is from −155 ° C. to 155 ° C. 5.