JPH09106113A - Solid toner for developing electrostatic charge image - Google Patents

Abstract

PROBLEM TO BE SOLVED: To almost eliminate aggregation and sweating phenomena of toner particles with lapse of time and to decrease changes in the charge density with lapse of time by incorporating a crystalline wax and a polymer wax prepared by polymn. of specified α-olefin into the toner. SOLUTION: This electrostatic charge image developing toner is provided by dispersing toner particles containing at least a coloring agent, a binder resin and a charge controlling agent as the main component in an electric insulating medium which is solid at normal temp. and changes into liquid by heating. The developer also contains a crystalline wax and a polymer wax prepared by polymn. of α-olefin having 19-60 carbon number. As for the electric insulating medium, a crystalline wax is used in a large amt. It is preferable to use so-called n-paraffin wax having straight-chain alkylene chains as the crystalline wax because a large effect can be obtd. As for the polymer wax, a polymer prepared by polymn. of α-olefin having 19-60 carbon number as the essential component is preferably used.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electrostatic charge developing toner used in wet development of an electrostatic charge image in an electrophotographic process or the like, and particularly to an electrostatic charge developing toner having improved handleability and stability over time. The present invention relates to a solid toner for charge development.

[0002]

2. Description of the Related Art In an electrophotographic process, a method of irradiating a uniformly charged photoconductor with light or developing an electrostatic charge image formed on a dielectric with a needle electrode or the like is roughly classified into a dry developing method. And a wet development method.

[0003] The dry development method has advantages over the wet development method in terms of handleability and preservability of a developer. However, in order to meet the demand for high-quality images, which is increasing in recent years, as seen in video printers for printing electronic still photographs, it is necessary to give a step to wet development.

On the other hand, the wet development method uses a liquid developer in which a colorant is dispersed in an electrically insulating liquid together with a resin, a charge control agent, and the like. It has features such as excellent resolution and gradation.

However, in the developing method using a liquid developer at room temperature, handling of the developer is troublesome, and frequent maintenance is required to always obtain a stable image. Further, in the liquid developer, aggregation and sedimentation of toner particles are unavoidable, and there are problems in terms of stability during long-term storage and waste liquid treatment.

In order to solve the above problems of the wet development method, in JP-A-2-6967, a developer in which a colorant is dispersed in an electrically insulating organic substance which is solid at room temperature is heated and liquefied to be liquefied. We have proposed a new electrostatic latent image developing method in which an electrostatic latent image is wet-developed with a developer.

The developer used in this developing method is called solid toner, and is proposed in Japanese Patent Laid-Open No. 2-6966.

The solid toner proposed in the above-mentioned publication is, for example, a colorant paste in which carbon black or a pigment is dispersed in an electrically insulating liquid, which is solid at room temperature such as paraffin wax together with a resin, a charge control agent and the like. It is manufactured by dispersing it in an electrically insulating organic material.

In such a solid toner, toner particles aggregate with the passage of time, a so-called sweating phenomenon is observed in which the electrically insulating liquid contained in the colorant paste oozes out on the surface, and the charge density is changed with the passage of time. The stability was deteriorated over time, and the practical properties were low.

[0010]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a solid toner which has almost no aggregation of toner particles or perspiration phenomenon over time and has a small change in charge density over time.

[0011]

Means for Solving the Problems The inventors of the present invention have conducted diligent research to solve the above problems, and the cause of the above problems is that the foreign substances are eliminated by the crystal growth which occurs below the melting point of the crystalline wax. Further, it was found that the crystal of the crystalline wax can be miniaturized and crystal growth can be suppressed by adding a certain wax-like substance to the present invention, resulting in the present invention.

That is, the present invention provides toner particles containing at least a colorant, a binder resin and a charge control agent as main components,
In a developer for electrostatic charge development, which is dispersed in an electrically insulating medium which is solid at room temperature and which is liquefied by heating, a crystalline wax and a polymer wax obtained by polymerizing an α-olefin having 19 to 60 carbon atoms are used. The present invention is intended to provide a solid toner for electrostatic charge development, which is characterized by containing the above.

Next, the present invention will be described in detail. The electrically insulating medium which is solid at least at room temperature and which is liquefied by heating used in the present invention is an electrically insulating organic substance having a melting point of 30 ° C. or higher, more preferably 40 ° C. or higher. Although the upper limit of the melting point is not particularly specified, it is practically about 100 ° C. or more, preferably 80 ° C. or less. This is because the extra energy is consumed for heating even if the melting point is too high.

Examples of the electrically insulating medium satisfying these requirements include paraffins, waxes, and mixtures thereof. Examples of paraffins include various normal paraffins having 19 to 60 carbon atoms from nonadecane to hexacontane. Examples of waxes include plant waxes such as carnauba wax and cotton wax, animal waxes such as beeswax, ozokerite, and petroleum waxes such as paraffin wax, microcrystalline wax and petrolatum. As these media, it is preferable to use a dielectric material having a dielectric constant of about 1.9 to 2.3.

A crystalline wax is often used as an electrically insulating medium. As the crystalline wax, it is preferable to use a so-called n-paraffin wax having a linear alkylene chain because the effect of the present invention described later is more greatly exhibited.

Α having 19 to 60 carbon atoms used in the present invention
A polymer wax formed by polymerizing an olefin (hereinafter referred to as α
-It is called an olefin polymer wax. As the above), a polymer obtained by polymerizing an α-olefin having 19 to 60 carbon atoms as an essential component is used. This polymer may be a homopolymer of an α-olefin having a single carbon number, or may be a polymer of an α-olefin having a different carbon number.
Of course, it may be a copolymer of α-olefin and another polymerizable monomer.

The other polymerizable monomer, which is a copolymerization component used as necessary, is, for example, ethylene,
Olefin such as propylene and butene, (meth) acrylic acid ester and the like can be used.

As the α-olefin polymer wax used in the present invention, those having a weight average molecular weight of about 500 to 8,000 and a softening point of 30 to 80 ° C. have good compatibility with the crystalline wax, It is preferable because the effects of the invention can be more easily exhibited. Further, as the α-olefin polymer wax, a polymer wax formed by polymerizing as an α-olefin main component having 30 to 40 carbon atoms is preferable.

The α-olefin polymer wax can be produced by a known and commonly used method. For example, α-olefin polymer wax having 19 to 60 carbon atoms can be used.
-It is obtained by radically polymerizing a monomer containing an olefin as an essential component using a polymerization initiator. The α-olefin polymer wax of the present invention includes WEISSENN
WAX (manufactured by Nippon Seiro Co., Ltd.) is preferably used. Said W
EISSENN WAX, for example, WEISSEN 0252C, WEISSENN
0252H, WEISSEN 0453 (manufactured by Nippon Seiro Co., Ltd.) and the like.

The amount of the α-olefin polymer added is 1 to 50% by weight, preferably 5 to 20% by weight, based on the dispersion medium obtained by removing the colorant and the binder resin from the entire solid toner. Just do it.

The weight ratio of the crystalline wax and the α-olefin polymer wax is not particularly limited, but the crystalline wax / α-olefin polymer wax (weight ratio) = 99/1 to 50 /. 50, especially 95/5
It is preferably set to 80/20.

The binder resin used in the present invention includes
Known ones can be used without particular limitation, but for example, butadiene rubber, styrene-butadiene rubber, cyclized rubber,
Rubbers such as natural rubber, styrene resins, vinyltoluene resins, acrylic resins, methacrylic resins, polyester resins, polycarbonate resins, polyvinyl acetate resins and other synthetic resins, rosin resins, hydrogenated rosins Examples of the resin include alkyd resins containing modified alkyds such as system resins and linseed oil-modified alkyd resins, and natural resins such as polyterpenes.

In addition, modified phenol resins such as phenol resins and phenol formalin resins, pentaerythritol phthalate, coumarone-indene resins, ester gum resins, vegetable oil polyamide resins, etc. are also useful, and polyvinyl chloride is also useful. , Halogenated hydrocarbon polymers such as chlorinated polypropylene, synthetic rubbers such as vinyltoluene-butadiene, butadiene-isoprene, 2-ethylexylmethacrylate, laurylmethacrylate,
Polymers of acrylic monomers having long-chain alkyl groups such as stearyl methacrylate, lauryl acrylate, and octyl acrylate, or copolymers thereof with other polymerizable monomers (for example, styrene-lauryl methacrylate copolymer, acrylic acid -Lauryl methacrylate copolymer etc.), polyolefins such as polyethylene, polyterpenes etc. can also be used.

As the binder resin, an amphipathic resin is preferable from the viewpoint of dispersibility and fixing property of toner particles. An amphipathic resin is a resin having both a soluble portion and an insoluble portion in a dispersion medium in one molecule. Examples of such a resin include the following.

That is, for example, an acrylic copolymer soluble in an electrically insulating medium liquid consisting of methyl methacrylate and an acrylic ester or a long-chain acrylic ester of methacrylic acid (as described in Japanese Patent Publication No. 20996); A molecular structure in which a first polymer chain made of a vinyl polymer soluble in the electrically insulating medium liquid and a second polymer chain made of a vinyl polymer insoluble in the medium liquid are bonded to each other through a urethane bond A non-gelled graft polymer having the entire molecule insoluble in the above-mentioned medium liquid (described in JP-A-58-122557); a vinyl polymer having a cross-linking reactive functional group in the molecular side chain. A cross-linked polymer that is soluble in the electrically insulating medium liquid, and a vinyl polymer insoluble in the medium liquid obtained by copolymerizing a vinyl monomer having a basic nitrogen atom or an amide group in the molecule with a vinyl acetate monomer. A vinyl copolymer which is composed of a nyl copolymer and is insoluble in a carrier liquid is a polymer which is captured by the cross-linked polymer (described in JP-A-63-208866).
And the like, and the latter two are particularly preferably used in terms of dispersibility and fixing property of toner particles.

The charge control agent used in the present invention includes:
Known ones are used as appropriate. For example, naphthenic acid,
Metal salts of fatty acids such as octenoic acid, oleic acid, stearic acid, isostearic acid or lauric acid, metal salts of sulfosuccinic acid esters, phosphoric acid ester metal salts, aromatic carboxylic acid metal salts, aromatic sulfonic acid metal salts, etc. is there. The amount of these charge control agents is not particularly limited, but is preferably 0.5 to 5 parts by weight per 100 parts by weight of the total of the colorant and the binder resin described below.

In order to improve the charge of the colorant, SiO ₂ , Al ₂ O ₃ , TiO ₂ , ZnO, Ga ₂ O ₃ ,
Fine particles of metal oxides such as In ₂ O ₃ , GeO ₂ , SnO ₂ , PbO ₂ and MgO, or a mixture thereof may be added as a charge enhancer.

As the dye and / or pigment particles in the present invention, conventionally known inorganic pigments, organic pigments, dyes and mixtures thereof can be used. As the colorant, a dye and / or pigment particles are dispersed in a synthetic resin having a solubility parameter of 8.5 or more and a softening point of 45 to 150 ° C., or a coupling agent or the like is used to disperse organic substances on the pigment surface. The resin-dispersed colorant of the former is particularly preferably used because it is preferable to use a colorant or the like which has been subjected to a coating treatment by directly reacting with the resin, because the dispersibility is good and aggregation is less likely to occur.

Examples of the inorganic pigments include chromium pigments, cadmium pigments, iron pigments, cobalt pigments,
Ultramarine, dark blue, etc. are mentioned.

Specific examples of organic pigments and dyes include carbon black; phthalocyanine pigments such as phthalocyanine copper; quinacridone pigments such as quinacridone magenta and quinacridone red; Hansa Yellow;
Azo pigments such as Disazo Yellow, Permanent Yellow, Permanent Red, Naphthol Red; Spirit Black SB, Nigrosine Base, Oil Black B
Nigrosine dyes such as W, oil blue, alkali blue and the like can be mentioned.

The synthetic resin used for obtaining the colorant varies depending on the electrically insulating medium used, but if listed, for example, a styrene resin [Picostic A75, D75, manufactured by Esso Chemical Co., Ltd.,
D100 etc.], maleic acid resin [Arakawa Chemical Industry Co., Ltd.
Ester gum M-90,100, Marquide No1,2,5,6,8, Beckasite 1110, 11 manufactured by Dainippon Ink and Chemicals, Inc.
11, F-231,1120, etc.], phenolic resin [Dainippon Ink and Chemicals Co., Ltd. Super Beckasite 1001,3011,
Beckasite 1100, 1123, etc.], epoxy resin [Dainippon Ink and Chemicals, Inc. Epicron 1050,4055,70]
50, Shell Petroleum Epicoat 1001,1004,1007
Etc.], ketone resin [Alon KR-SS, etc., manufactured by Toa Gosei Chemical Industry Co., Ltd.], butyral resin [Sekisui Chemical Co., Ltd.]
Esrec BM-1,2 etc.), methacrylic resin [Dianal BR-64,77,85,90,106 manufactured by Mitsubishi Rayon Co., Ltd.]
Etc.] and polyester resins. They are,
They can be used alone or as a mixture of two or more. As the synthetic resin, it is preferable to use a synthetic resin that is insoluble in the electrically insulating medium, since the resistance of the solid toner finally obtained is increased and the developing characteristics are improved.

To make a colorant by dispersing the synthetic resin for obtaining the colorant and the pigment and / or dye,
The pigment and / or dye and the synthetic resin can be obtained by, for example, heating, melting and kneading with a roll mill, a kneader or the like, cooling and pulverizing.

In this case, the dye and / or pigment particles 1
0.5 parts by weight of the above synthetic resin for obtaining a coloring agent
What was obtained so that it might be set to -100 parts by weight, and especially 1 to 30 parts by weight is preferable.

The coating-treated colorant is directly applied by, for example, immersing the pigment or the like in a coupling agent solution to adhere the active ingredient to the surface of the pigment or the like and then drying or heating at room temperature. It can be obtained by reacting. Examples of the coupling agent include silane coupling agents such as aminosilane, epoxysilane, and mercaptosilane, and titanium coupling agents.

In order to obtain the solid toner for electrostatic charge development according to the present invention, a fine powdered colorant, the above-mentioned colorant, and the above-mentioned finely pulverized colorant are used by using a disperser capable of heating the electrically insulating medium to a liquid state by an appropriate heating means. A binder resin, a charge control agent, and if necessary, an auxiliary agent such as a dispersant or a charge enhancer is dispersed in the electrically insulating medium.

Alternatively, in order to obtain particles having a smaller particle size, the powdered colorant, the binder resin, the charge control agent, and if necessary, an auxiliary agent such as a dispersant and a charge enhancer are used at room temperature. In a liquid high resistance, low dielectric constant, electrically insulating medium, it is dispersed beforehand by using a ball mill, an attritor, etc., and then the paste-like separated solid substance is solid at room temperature by means such as centrifugation. Alternatively, they may be dispersed in an electrically insulating medium that is liquefied by heating. At this time, a charge control agent may be added in order to give the toner particles a desired charge.

At this time, as the electrically insulating medium having a high resistance and a low dielectric constant which is liquid at room temperature, for example, hexane, pentane,
100-250 such as octane, nonane, decane, undecane, dodecane and organic solvents sold under the trade name of Isopar G, H, K, L, M etc. manufactured by Exxon Chemical Co.
Various aliphatic hydrocarbon solvents having a boiling point in the temperature range of ° C and having a volume resistivity of 10 ⁹ Ω · cm or more and a dielectric constant of less than 3 can be used.

Finally, the solid toner for electrostatic charge development of the present invention is obtained by cooling to room temperature.

The solid toner for electrostatic charge development of the present invention can be used by putting it in a suitable container, or by coating or impregnating it on a suitable support. It is necessary to provide an appropriate heating means to the above-mentioned container or support so that the solid toner for electrostatic charge development can be kept in a molten state during use.

The developing process to which the solid toner for electrostatic charge development according to the present invention is applied may be any conventional process, regardless of the method for forming an electrostatic latent image and the type of photosensitive substrate. Absent. For example, as far as the photosensitive substrate is concerned, it can be used for a photosensitive substrate made of a well-known organic photoconductor or inorganic photoconductor.

The solid toner for electrostatic charge development of the present invention can also be applied to a means other than photosensitization, for example, when developing an electrostatic latent image formed on a dielectric by a charging needle.

To develop an electrostatic charge image using the solid toner for electrostatic charge development of the present invention, for example, the solid toner is melted by an appropriate means as described above, and the above-mentioned charge on which an electrostatic latent image is formed. The carrier is dipped, or a toner in a molten state is coated on a metal roller heated by a suitable heating means so as to keep the molten state, and this is brought into contact with the charge carrier on which an electrostatic latent image is formed. And the like.

[0043]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will now be described in detail with reference to the preferred embodiments of the present invention. First pigment 1
Melt heating is performed using 1 to 5 parts by weight of a synthetic resin having a solubility parameter of 8.5 or more and a softening point of 45 to 150 ° C., which is insoluble in a high-resistance low-dielectric constant electrical insulating medium, which is liquid at room temperature, which will be described later. Melt kneading to prepare a colorant in which the pigment particles are dispersed in a resin matrix. Alternatively, a coloring agent composed of the pigment particles surface-treated is prepared by wetting with 0.05 to 5 parts by weight of the silane coupling agent per 1 part by weight of the pigment and then drying.

Further, as an amphiphilic resin, a vinyl polymer having an average molecular weight of 30,000 to 1,000,000 and soluble in an electrically insulating medium having a high resistance and a low dielectric constant which is liquid at room temperature and has a long chain alkyl group and a hydroxyl group is used. And a second polymer chain composed of a vinyl polymer having a hydroxyl group, which is insoluble in the electrically insulating medium of the liquid, and a urethane bond is formed by a reaction between the hydroxyl group and polyisocyanate. A dispersion of a non-gelled graft polymer having a molecular structure in which the above are formed and mutually bonded is insoluble in and dispersed in the electrically insulating medium of the liquid as a whole.

10 to 50 parts by weight of the amphipathic resin (nonvolatile component), 0.5 to 5 parts by weight of the charge control agent, and 100 to 100 parts by weight of the colorant prepared above, a liquid having a high resistance and a low dielectric constant at room temperature. After adding 150 to 600 parts by weight of the electrically insulating medium, mixing and kneading, the mixture is centrifuged to obtain a separated solid matter.

Further, 3 to 100 parts by weight of crystalline n-paraffin wax having a softening point of 35 to 50 ° C.
20 parts by weight of softening point 45 to 80 ° C., carbon number 30 to 40
The polymer wax obtained by polymerizing the α-olefin as the main component is melt-mixed in advance to obtain a wax mixture.

Using 800 to 1500 parts by weight of the wax mixture per 100 parts by weight of the separated solid matter (nonvolatile matter), they are heated and melt-mixed to make them uniform,
After cooling, a solid toner for developing an electrostatic image which is solid at room temperature is obtained.

[0048]

EXAMPLES The present invention will now be described in more detail with reference to examples, but the present invention is not limited thereto.
In the following examples, "parts" and "%" represent "parts by weight" and "% by weight", respectively.

Resin Synthesis Example Resin A Stearyl acrylate (80 parts by weight) and methyl acrylate (20 parts by weight) are dissolved in 500 parts by weight of toluene, 5 parts by weight of AIBN (azobisisobutylnitrile) is added as a reaction initiator, and a nitrogen atmosphere is added. Polymerization was carried out at 75 ° C for 5 hours, and the mixture was purified by precipitation from an n-hexane / ethanol mixed solvent three times. Then, the solvent was removed to obtain a solid resin at room temperature.

Resin B 93.3 parts of lauryl methacrylate, 3.7 parts of hydroxypropyl methacrylate, 3.0 parts of "Acryester PA" (monomer manufactured by Mitsubishi Rayon Co., Ltd.), 2.5 parts of "Perbutyl O" (polymerization catalyst manufactured by NOF CORPORATION) and "Perbutyl" Z "(polymerization catalyst manufactured by NOF CORPORATION) 1.5 parts" ISOPER G "(aliphatic hydrocarbon solvent manufactured by Exxon Chemical Co.) 100 parts nitrogen gas introduction pipe,
The mixture was charged into a reaction vessel equipped with a stirrer and a cooling tube, heated to 120 ° C., and reacted at 120 ° C. for 8 hours to obtain a polymer having a nonvolatile content of 48.8%.

Then, the temperature was lowered to 70 ° C., 5.7 parts of isophorone diisocyanate, 0.05 part by weight of dibutyltin dilaurate and 5.7 parts of “Isopar G” were added, and a urethanization reaction was carried out at 70 ° C. for 4 hours, followed by cooling, An intermediate solution having a nonvolatile content of 48.6% was obtained.

80 parts of the above solution of the intermediate was charged into a reaction vessel similar to the above, and 105 parts of "Isopar G", 2.7 parts of hydroxypropyl methacrylate, 28.7 parts of methyl methacrylate, 28.6 parts of 2-ethylhexyl methacrylate and perbutyl D were further added. 0.3 parts of (polymerization catalyst manufactured by NOF Corporation) and 0.3 parts of perbutyl Z (polymerization catalyst manufactured by NOF CORPORATION) were added and reacted at 110 ° C. for 5 hours, followed by Isopar G (manufactured by Exxon Chemical Co.).
Add 83 parts of (aliphatic hydrocarbon solvent) and cool to obtain a nonvolatile content of 2
An 8.5% solution of the graft polymer was obtained. The fixing agent dispersion liquid thus obtained was designated as "resin B".

(Production of Colorant) (Colorant 1) Carbon Black Elftex 8 (manufactured by Cabot Corporation) 20 parts by weight Oil Black BW (manufactured by Orient Chemical Industry Co., Ltd.) 5 parts by weight Epicoat 1004 (manufactured by Shell Petroleum Co.) 50 parts by weight Epicoat 1007 (manufactured by Shell Oil Co., Ltd.) 25 parts by weight

The mixture having the above composition was melt-kneaded using a pressure kneader, and the obtained colored meat was crushed using a funnel plex to obtain 1 mm pass color fine powder. The coloring agent thus obtained is referred to as coloring agent 1.
Each of the epicoats is a synthetic resin having a solubility parameter of 8.5 or more and a softening point of 45 to 150 ° C.

(Colorant 2) Fastgen Blue TGR [manufactured by Dainippon Ink and Chemicals, Inc.] 30 parts by weight Epicoat 1004 (manufactured by Shell Oil Co., Ltd.) 30 parts by weight Picostic D-75 (manufactured by Esso Chemical Co., Ltd.) 40 parts by weight Department

A mixture having the above composition was added to the colorant 1
A cyan colorant fine powder was obtained in the same manner as in Production Example 1. The coloring agent thus obtained is referred to as coloring agent 2. In addition, the above-mentioned picotic has a solubility parameter of 8.
A synthetic resin having a softening point of 5 to 5 ° C and a softening point of 45 to 150 ° C.

(Colorant 3) Carbon black Raven 1060 (manufactured by Colombyan Carbon Co., Ltd.) 100 parts by weight Silane coupling agent A-1110 (manufactured by Nippon Unicar Co., Ltd.) 20 parts by weight Ethanol 360 parts by weight

The above mixture was uniformly dispersed and stirred with a homomixer, filtered and dried at room temperature to obtain a silane coupling agent-treated carbon. Next, it was pulverized with a small pulverizer to obtain a colored fine powder. The coloring agent thus obtained is called coloring agent 3.

Example 1 60 parts by weight of the colorant 1 20 parts by weight of the resin B zirconium naphthenate [Nonvolatile content 40% by Dainippon Ink and Chemicals, Inc.] 1.5 parts by weight Isopar G (exxon chemical company) 220 parts by weight

The above mixture was uniformly mixed and kneaded with a ball mill. This dispersion was diluted with Isopar G so that the nonvolatile content became 10% to prepare a liquid concentrated toner. The liquid-concentrated toner was centrifuged to remove the separated liquid to obtain a separated solid substance having a nonvolatile content of 63%. The separated solid matter 34
g and n-paraffin wax [softening point 42 ° C. to 44 ° C.
℃: manufactured by Wako Pure Chemical Industries, Ltd.] WEISSEN 0252C in 234 g
[Polymer wax manufactured by Nippon Seiro Co., Ltd., polymerized mainly with α-olefin having 30 to 40 carbon atoms, softening point 7
[3 ° C.] 26 g melt-mixed was dispersed with 1 kg of zirconia beads having a diameter of 2 mm for 2 hours by a small jacketed heating attritor heated to 60 ° C. to obtain a solid toner.

COMPARATIVE EXAMPLE 1 In Example 1, WEISSEN
A solid toner was manufactured in the same manner as in Example 1 except that 26 g of n-paraffin wax was not used and 260 g of it was used.

(Embodiment 2) WEISSEN 0 in Embodiment 1
Instead of 252C, WEISSEN 0453 [manufactured by Nippon Seiro Co., Ltd.,
A solid toner was obtained in the same manner as in Example 1 except that the same amount of the softening point of 55 ° C. was used.

(Example 3) 60 parts by weight of the colorant 2 40 parts by weight of the resin B 40 parts by weight of cobalt naphthenate [manufactured by Dainippon Ink and Chemicals, Inc., non-volatile content: 50%] 3 parts by weight Isopar H (exxon chemical company) 280 parts by weight

In the same manner as in Example 1, the above mixture was uniformly mixed and kneaded by a ball mill to prepare a liquid concentrated toner having a nonvolatile content of 10%. The liquid-concentrated toner was subjected to a centrifugal separator to remove the separated liquid to obtain a separated solid substance having a nonvolatile content of 60%. 37 g of the above separated solid and 247 g of n-paraffin wax [melting point 42 ° C. to 44 ° C .: manufactured by Wako Pure Chemical Industries, Ltd.] WEISSEN 0453 [manufactured by Nippon Seiro Co., Ltd., carbon number 30-40]
Of a polymer wax obtained by polymerizing α-olefin as a main component, and a mixture of 13 g of a softening point of 55 ° C.] melted and mixed with 1 kg of zirconia beads having a diameter of 2 mm to 60
A small toner disperser with a heating jacket, Dispermat TX-04, heated to 0 ° C., was dispersed for 2 hours to obtain a solid toner.

(Example 4) 20 parts by weight of the colorant 1 5 parts by weight of the resin A 1 part by weight of zirconyl stearate Paraffin wax 115 (melting point 47 ° C. made by Nippon Steel Co., Ltd.) 285 parts by weight 22 parts by weight of WEISSEN 0252C The above mixture 1 kg of zirconia beads having a diameter of 2 mm was dispersed for 2 hours in a small disperser TX-04 with a jacket for heating heated to 70 ° C. to obtain a solid toner.

(Example 5) 10 parts by weight of carbon treated with the above silane coupling agent 20 parts by weight of resin A 160 parts by weight of ISOPAR H

The above mixture was uniformly mixed and kneaded by a ball mill to prepare a liquid concentrated toner. The liquid-concentrated toner was centrifuged to remove the separated liquid to obtain a separated solid substance having a nonvolatile content of 63%. 34 g of the separated solid matter and paraffin wax (melting point 42 ° C. to 44 ° C .: manufactured by Wako Pure Chemical Industries, Ltd.) 22
A mixture of 13 g of WEISSEN 0453 (manufactured by Nippon Steel Co., Ltd.) in 5 g and 0.3 g of zirconium octylate (Nippon Kagaku Sangyo Co., Ltd., nonvolatile content 40%) was used at 60 ° C. using 1 kg of zirconia beads having a diameter of 2 mm. Disperser TX-0 with a jacket for heating
4 for 1 hour to obtain a solid toner.

(Evaluation of Toner Properties) The presence or absence of a sweating phenomenon, the charge density of solid toner, the average particle size, and the degree of aggregation of toner particles by microscopic observation were measured immediately after production and after 3 months, and the change in toner properties with time was measured. Was evaluated.

The sweating was evaluated by visually observing the surface of the solid toner. The charge density of solid toner is
Distance between electrodes heated to 50 ° C: 2 mm, electrode area: 25 cm
^When the cell ² was filled with the solid toner and was in a molten state, DC 1 kV was applied for 30 seconds, and the current flowing in the cell was integrated to measure.

The average particle size was measured using a centrifugal sedimentation type particle size distribution analyzer SA-CP2 (manufactured by Shimadzu Corporation). The degree of aggregation of the toner particles depends on the optical microscope B manufactured by Olympus Corporation.
It was evaluated by visual observation using H-2.

The evaluation results for each item are shown in the table below (note that “after manufacturing” in the table means immediately after manufacturing).

[0072]

[Table 1] Note: The unit of charge density is μC / cm ³ , and the unit of average particle size is μm.

As can be seen from the results of Example 1 and Comparative Example 1, the solid toner of the present invention is free from perspiration (bleeding) as compared with the conventional solid toner containing only crystalline wax, and the toner particles are aged with time. It can be seen that there is no aggregation and that the change in charge density over time is extremely small.

[0074]

According to the present invention, since the crystalline wax is used in combination with the wax composed of the α-olefin polymer having 19 to 60 carbon atoms, the aggregation of toner particles and the perspiration of the electrically insulating medium liquid with time are prevented. In other words, a particularly remarkable effect is obtained in that a solid toner having a small change in charge density over time can be obtained.

Claims (6)

[Claims] 1. A developer for electrostatic charge development, comprising toner particles containing at least a colorant, a binder resin and a charge control agent as main components, dispersed in an electrically insulating medium which is solid at room temperature and liquefies when heated. A solid toner for electrostatic charge development, comprising a crystalline wax and a polymer wax obtained by polymerizing an α-olefin having 19 to 60 carbon atoms. 2. The toner according to claim 1, wherein the crystalline wax is n-paraffin wax. 3. n-paraffin wax / C19-
The toner according to claim 2, wherein a polymer wax (weight ratio) formed by polymerizing 60 α-olefins is 99/1 to 50/50. 4. The coloring agent comprises dye and / or pigment particles,
With a solubility parameter of 8.5 or more, a softening point of 45 to 1
The toner according to claim 1, which is a colorant dispersed in a synthetic resin in the range of 50 ° C. 5. A coloring agent is dye and / or pigment particles,
A colorant obtained by reacting with a coupling agent.
The toner described in the above. 6. The toner according to claim 1, wherein the binder resin is an amphipathic resin.