JPH10268551A - Electrostatic latent image developing toner composition, electrostatic latent image developer and image forming method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable an image to be fixed at a low fixing temperature, to eliminate the problems of offset-resistance and maintenance stability and to improve the fixation strength to the transferred material by dispersing fine particles which are formed of releasable material and covered with resin into binding resin. SOLUTION: The toner composition is formed of at least the binding resin, coloring agent and fine particles which are covered with the resin and formed of the releasable material, and the fine particles are dispersed in the binding resin. It is preferable to select polyurea and polyurethane as the resin for covering the releasable fine particles. It is preferable that the electrostatic latent image developing toner composition may be color toner, and also it is preferable that the binding resin is polyester. It is allowed to manufacture the toner composition by melting/kneading the binding resin, the coloring agent and the releasable fine particles covered with the resin, and also, it is possible to manufacture the toner composition by adding the releasable fine particles together with the coloring agent at the process of manufacturing polymerized toner, that is, at the process of the suspension polymerization of monomer for forming the binding resin and the emulsion polymerization, etc.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a toner composition for developing an electrostatic latent image, and more particularly to a toner composition for developing an electrostatic latent image used in a copying machine, a printer or the like employing a hot roll fixing system. And an image forming method using the same.

[0002]

2. Description of the Related Art Generally, in the electrophotographic method or the electrostatic printing method, a dry developer is often used as a developer for developing an electrostatic latent image.
A toner in which a colorant such as a dye or pigment, and, if necessary, a release agent and a charge control agent are dispersed in a binder resin is used.

[0003] Dry development methods in various electrostatic copying systems that are currently in practical use include a two-component development method using a carrier such as toner and iron powder, and a toner containing a magnetic substance inside the toner without using a carrier. Is a typical one-component magnetic developing system. Further, as a method for fixing a toner image, a heat fixing method using a heating roll is generally used. This method has high thermal efficiency and can perform high-speed fixing. Therefore, part of the toner image adheres to the heating roll, and the adhered toner is re-transferred, thereby contaminating the copied image.
A so-called offset phenomenon may occur. In order to prevent this phenomenon, the surface of the heating roll is formed of silicone rubber or fluororesin having excellent releasability from toner, and a releasable liquid such as silicone oil is supplied to the surface as an anti-offset liquid. The method has been adopted. Although this method is extremely effective in preventing the occurrence of the toner offset phenomenon, the offset prevention liquid is heated and evaporated to give an unpleasant odor,
There is a problem that a device for supplying the offset prevention liquid is required.

[0004] In recent years, in order to satisfy strong demands for downsizing and energy saving of apparatuses, toners having lower energy fixing properties have been required. For example, a reduction in the diameter of the heating roll shortens the time from when the heating roll is heated to when the paper on which the toner image has been transferred passes, so that a low-temperature fixing toner is required as the toner. It becomes necessary to use a highly conductive material. However, when the low-temperature fixing property of the toner is increased, when the heating roll fixing method is applied, the toner adheres to the heating roll, and the above-described offset phenomenon that the next copy is stained.
Alternatively, a phenomenon (finger mark) in which the fixed image is destroyed by a finger for peeling the sheet after passing through the heating roll, and further, when the toner image after fixing is rubbed with white paper, a part of the toner image is broken and rubbed. A phenomenon (smudge) that shifts to a blank sheet occurs, which adversely affects the operation.

[0005] In order to solve such a problem, there is known a method (Japanese Patent Publication No. 52-3304) in which a toner contains a releasing agent such as a resin having a releasing property. The release agent-added toner has good releasability from a heating roll and good offset resistance, but the release agent has a large domain in the resin due to low compatibility between the release agent and the binder resin. During the pulverization step in the formation and production of the toner, there is a problem that the formed domain is easily pulverized at the portion of the formed domain, and the release agent is easily exposed on the toner surface. From the viewpoint of energy saving, it is necessary that the resin constituting the release agent has a low melting point. However, if such a resin is present on the surface of the toner particles, the fluidity of the toner deteriorates, and the toner in the developing unit is deteriorated. The disadvantages are that the supply is not performed smoothly, the toner image formed on the electrostatic latent image holder formed by development is not smoothly transferred to the copy material, and that the toner storability in a high-temperature atmosphere is poor. is there.

Further, JP-A-3-243965, JP-A-3-264951, JP-A-5-45925, JP-A-8-262784, and the like disclose the surface abundance of the release agent and their A toner having a defined domain diameter is disclosed. However, in the cases described in these publications, since the release agent is exposed on the toner surface,
The fluidity of the toner deteriorates, the toner is not supplied smoothly in the developing section of the developing device, the transfer cannot be performed smoothly, and the disadvantage that the toner storability in a high-temperature atmosphere is poor. is there.

Further, Japanese Patent Laid-Open No. 1-257853,
Japanese Patent Application Laid-Open No. 3-125126 discloses a toner in which fine resin particles containing a release agent uniformly dispersed are fixed on the toner surface. However, since the release agent is surrounded by the resin, Although the fluidity and transferability of the toner are improved, there is a drawback that a sufficient release property cannot be obtained because the release agent does not appear on the surface of the fine resin particles unless the surrounding resin film is broken. . JP-A-2-264266 discloses a method of mechanically fixing resin fine particles and release agent fine particles to the surface of toner particles, but has a drawback that the fluidity and transferability of the toner are not sufficiently improved. . JP 4
No. 182,661 discloses a method in which resin fine particles and release agent fine particles are adhered to the surface of toner particles and treated with a solvent that dissolves the resin fine particles to form a resin layer containing a release agent on the toner particle surfaces. However, since the release agent is coated with the resin, there is a disadvantage that sufficient release properties cannot be obtained.

[0008]

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems in the prior art, and an object of the present invention is to enable fixing at a low fixing temperature, and to provide offset resistance and storage stability. It is an object of the present invention to provide a toner composition for developing an electrostatic latent image, which does not cause any problem in the developing property and has excellent fixing strength to a transfer material, an electrostatic latent image developer using the same, and an image forming method.

[0009]

The above object of the present invention is attained by using the following toner composition for developing an electrostatic latent image. That is, the first of the electrostatic latent image developing toner composition of the present invention comprises at least a binder resin, a colorant, and fine particles of a release material coated with the resin,
The fine particles are dispersed in a binder resin, and the second type is fine particles of a releasable material coated with a resin on toner particles comprising at least a binder resin and a colorant. Is mixed as an external additive. The first one of the electrostatic latent image developer of the present invention is the first one.
Comprising an electrostatic latent image developing toner composition and a carrier,
The second is composed of the second electrostatic latent image developing toner composition and a carrier.

Further, the image forming method of the present invention comprises a step of forming an electrostatic latent image on a latent image holding member, a step of developing the electrostatic latent image using a developer, and a step of transferring the developed toner image. And a fixing step of heating and fixing the toner image on the transfer body, wherein the first or second electrostatic latent image developer is used as a developer. .

In the present invention, the resin for coating the fine particles of the releasable material in the first and second toner compositions for developing an electrostatic latent image is preferably selected from polyurea and polyurethane. The amount of the resin to be coated is preferably such that the composition ratio of the releasable material is 20% to 95% by weight, more preferably 5%.
It is in the range of 0-90%. Further, the fine particles of the release material coated with the resin preferably have an average particle diameter of 0.1 to 3 μm. The toner composition for developing an electrostatic latent image of the present invention is preferably a color toner. Further, the binder resin is preferably polyester.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION Fine particles of a releasable material coated with a resin according to the present invention can be manufactured by the following two-step manufacturing procedure. (1) Step of preparing fine particles for obtaining dispersion of release material (2) Resin film forming step of coating fine particles of release material with resin Obtain dispersion of release agent fine particles in fine particle preparation step of (1) As a method, for example, there are the following methods, and it is also available as a commercial product. That is, the liquid a (solvent) that dissolves the release material and the liquid a
The liquid b (dispersion medium) which is compatible with but does not dissolve the releasable material is used. After dissolving the releasable material in the liquid a, the releasable material is added to the liquid b which is stirred at a high speed. A method of precipitating the fine particles and obtaining a dispersion of the releasable material, by adding hot water to the liquid material obtained by hot-melting the releasable material while stirring at high speed, and cooling the obtained dispersion. A method for obtaining a dispersion of a release material, a liquid c (dispersion medium) that does not dissolve the release material and a release material, and dispersing the mixture using a dispersing device such as a ball mill. Known methods such as a method for obtaining a dispersion can be used. Further, in these dispersions, as a dispersion stabilizer, a known surfactant, a polymer dispersant,
Inorganic ions and the like can be contained alone or in combination.

Thereafter, in order to continuously carry out the resin film forming step (2), it is desirable to carry out the treatment without changing the solvent to be used. For this purpose, the solvent is a reactive monomer or a prepolymer. Must be soluble. Therefore, the method has a restriction that two kinds of solvents are used, whereas the method uses water. Therefore, the method is more preferable as the fine particle production step (1).

Hereinafter, the above steps in the present invention will be described more specifically. That is, after the release material is charged into the dispersion medium, the dispersion medium is heated so as to have a melting point of the release material or higher. In that case, you may add a well-known dispersion stabilizer as needed. In this step, treatment such as mechanical stirring and ultrasonic treatment may be performed in order to promote dispersion of the release material. After the temperature of the release material reaches a temperature at which the release material is sufficiently melted, the dispersion medium is rapidly cooled. By this step, a dispersion of the release material is obtained.

Next, a reactive monomer or prepolymer is first added to the above-mentioned dispersion liquid in order to coat the fine particles of the releasable material dispersed in the dispersion medium with a resin. One or more reactive monomers or prepolymers may be used. Next, a second reaction component capable of reacting with the reactive monomer or the prepolymer is added to the dispersion to form a fine resin film, for example, a polyurea or polyurethane film. In that case, heating may be performed as necessary to advance the reaction. Add a reactive monomer or prepolymer, stir and heat until the reaction proceeds and a resin film covering the fine particles of the release material is formed, wash with water, filter, then dry and coat with resin. Fine particles of the releasable material are obtained. In the drying step, it is preferable to perform freeze-drying in order to promptly perform complete drying and to take out at least a powder in which particles are weakly aggregated.

In the present invention, any releasing material can be used as long as it has the effect of melting and preventing toner from adhering to the heating roll when performing fixing by a heating and pressing method using a heating roll. However, specifically,
For example, the number average molecular weight of polypropylene, polyethylene, oxidized polypropylene, polyethylene oxide and the like is 600 to 600.
20,000 low molecular weight polyolefins; candelilla;
Plant natural waxes such as carnauba, rice, wood wax, jojoba, etc .; mineral natural waxes such as montan, ceresin, ozokerite; petroleum waxes such as paraffin, microcrystalline, petrolactam, and modified waxes thereof; palmitic acid, stearic acid And higher solid fatty acids such as behenic acid; higher fatty acids such as calcium stearate, aluminum stearate, calcium palmitate and zinc palmitate; alkaline earth metal salts, zinc salts and aluminum salts; higher such as octadecyl stearate and glycerin monostearate. Fatty acid esters; amides such as lauric acid amide, stearic acid amide, N, N'-ethylenebisoleic acid amide, N, N'-ethylenebisstearic acid amide; diheptadecyl ketone, diundecyl ketone and the like Tons, and the like, and the like.

As a dispersion medium for dispersing the release material,
It is desirable to dissolve the reactive monomer or prepolymer. For example, aliphatic esters such as ethyl acetate, ketones such as methyl ethyl ketone (MEK), aliphatic hydrocarbons such as n-hexane, aromatic hydrocarbons such as toluene, halogen-containing compounds such as dichloromethane, etc. The material is not particularly limited as long as it does not dissolve the release material, and a known material can be used. As the reactive monomer or prepolymer, a silyl isocyanate compound or a polyvalent isocyanate described below is preferably used.

The silyl isocyanate compound used in the present invention includes silyl isocyanate derivatives represented by the following formulas (I), (II) and (III) and condensates thereof. _{R m R 'k R "n} Si (NCO) 4-mkn (I) (RO) m (R'O) k (R" O) n Si (NCO) 4-mkn (II) R p (R'O ) _Q Si (NCO) _r (III) (where R, R ′ and R ″ each represent an alkyl group, an aryl group or an alkenyl group, and m, k and n are each an integer of 0 to 3) And m + k +
It satisfies n ≦ 3, p, q and r are each an integer of 1 or 2, and satisfies p + q + r = 4. )

Specific examples of the silyl isocyanate compound include (CH ₃ ) ₃ SiNCO and (C ₂ H ₅ ) ₃ SiN
CO, (C ₃ H ₇ ) ₃ SiNCO, (C ₄ H ₉ ) ₃ Si
NCO, (CH ₃ ) (C ₂ H ₅ ) (C ₃ H ₇ ) SiNC
O, (CH ₃ ) (C ₂ H ₅ ) ₂ SiNCO, (CH ₃ )
₂ (C ₂ H ₅ ) SiNCO, (CH ₃ ) ₂ Si (NC
_{O) 2, (C 2 H} 5) 2 Si (NCO) 2, (C
_{3 H 7) 2 Si (NCO} ) 2, (C 4 H 9) 2 Si (N
CO) ₂ , CH ₃ Si (NCO) ₃ , C ₂ H ₅ Si (N
CO) ₃ , C ₃ H ₇ Si (NCO) ₃ , C ₄ H ₉ Si
(NCO) ₃ , CH ₂ ＣＨCHSi (NCO) ₃ , CH ₂
= C (CH ₃ ) Si (NCO) ₃ , (CH ₃ O) ₃ Si
NCO, (C ₂ H ₅ O) ₃ SiNCO, (C ₃ H ₇ O)
₃ SiNCO, (C ₄ H ₉ O) ₃ SiNCO, (CH ₃
O) ₂ Si (NCO) ₂ , (C ₂ H ₅ O) ₂ Si (NC
O) ₂ , (C ₃ H ₇ O) ₂ Si (NCO) ₂ , (C ₄ H
₉ O) ₂ Si (NCO) ₂ , CH ₃ OSi (NC
_{O) 3, C 2 H 5} OSi (NCO) 3, C 3 H 7 OSi
(NCO) ₃ , C ₄ H ₉ OSi (NCO) ₃ , Si (N
CO) ₄ , (CH ₃ ) (CH ₃ O) ₂ SiNCO, (C
_{2 H 5) (C 2 H} 5 O) 2 SiNCO, (C 3 H 7)
(C ₂ H ₅ O) ₂ SiNCO, (C ₄ H ₉ ) (C ₃ H ₇
O) Si (NCO) ₂ , (CH ₃ ) (CH ₃ O) Si
(NCO) ₂ , (C ₂ H ₅ ) (C ₂ H ₅ O) Si (NC
O) ₂ , (C ₃ H ₇ ) (C ₂ H ₅ O) Si (NC
O) ₂ , (C ₄ H ₉ ) (C ₂ H ₅ O) Si (NC
_{O) 2, (C 6 H} 5 O) Si (NCO) 3, (C
_{6 H 5) 2 Si (NCO} ) 2 and the like. These silyl isocyanate compounds may be used alone or in combination of two or more.

As the polyvalent isocyanate compound, various compounds can be used. Specifically, for example, m-phenylene diisocyanate, p-phenylene diisocyanate, 2,6-tolylene diisocyanate, 2,4- Tolylene diisocyanate, naphthalene-
1,4-diisocyanate, diphenylmethane-4,
4'-diisocyanate, 3,3'-dimethoxy-4,
4'-biphenyl-diisocyanate, 3,3'-dimethylphenylmethane-4,4'-diisocyanate, xylylene-1,4-diisocyanate, 4,4'-diphenylpropane diisocyanate, trimethylene diisocyanate, hexamethylene diisocyanate, propylene 1,2-diisocyanate, butylene-1,2-
Diisocyanates such as diisocyanate, cyclohexylene-1,2-diisocyanate and cyclohexylene-1,4-diisocyanate; 4,4 ', 4 "-triphenylmethane triisocyanate; toluene-2,4,6
Triisocyanates such as triisocyanates, 4,
4'-dimethyldiphenylmethane-2,2 ', 5,5'
Tetraisocyanates such as tetraisocyanate, adducts of hexamethylene diisocyanate and trimethylolpropane, adducts of 2,4-tolylenediisocyanate and trimethylolpropane, adducts of xylylenediisocyanate and trimethylolpropane, tolylenediisocyanate and hexane Isocyanate prepolymers such as adducts of triols.

As the second reaction component capable of reacting with the reactive monomer or the prepolymer, any one capable of reacting with the reactive monomer or the prepolymer can be used. For example, when the resin that coats the release material is polyurea, water or polyamines are used, and when the resin is polyurethane, a water-containing compound (polyols) such as a polyhydric alcohol is used. In the case of a polyurea / polyurethane composite resin, water, a polyamine, a polyhydric alcohol, or the like, which is the second reaction component, may be used in combination.

Examples of the polyamines include ethylenediamine, trimethylenediamine, tetramethylenediamine, pentamethylenediamine, hexamethylenediamine, p-phenylenediamine, m-phenylenediamine, piperazine, 2-methylpiperazine, and 2,5-dimethyl. Piperazine, 2-hydroxytrimethylenediamine, diethylenetriamine, triethylenetriamine,
Examples include triethylenetetramine, diethylaminopropylamine, tetraethylenepentamine, and amine adducts of epoxy compounds.

Examples of the polyols include aliphatic,
Aromatic polyhydric alcohols, hydroxypolyesters, hydroxypolyalkylene ethers and the like can be used, and specifically, for example, the following polyols described in JP-A-60-49991 can be used. That is,
Ethylene glycol, 1,3-propanediol, 1,
4-butanediol, 1,5-pentanediol, 1,
6-hexanediol, 1,7-heptanediol,
1,8-octanediol, propylene glycol,
2,3-dihydroxybutane, 1,2-dihydroxybutane, 1,3-dihydroxybutane, 2,2-dimethyl-1,3-propanediol, 2,4-pentanediol, 2,5-hexanediol, 3- Methyl-1,5-
Pentanediol, 1,4-cyclohexanedimethanol, dihydroxycyclohexane, diethylene glycol, 1,2,6-trihydroxyhexane, 2-phenylpropylene glycol, 1,1,1-trimethylolpropane, hexanetriol, pentaerythritol, pentaerythritol Ethylene oxide adduct,
Glycerin ethylene oxide adduct, glycerin,
Condensation products of aromatic polyhydric alcohols such as 1,4-di (2-hydroxyethoxy) benzene and resorcinol dihydroxyethyl ether with alkylene oxides, p
-Xylylene glycol, m-xylylene glycol,
α, α'-dihydroxy-p-diisopropylbenzene, 4,4'-dihydroxydiphenylmethane, 2-
(P, p'-dihydroxydiphenylmethyl) benzyl alcohol, an adduct of bisphenol A with ethylene oxide, an adduct of bisphenol A with propylene oxide, and the like can be used. These polyols have a hydroxyl group ratio of 0.0 per mole of isocyanate groups.
It is preferable to use it in the range of 2 to 2 mol.

These compounds are added in order to form a resin which coats the fine particles of the release material. The amount of each of these compounds is 0.0 to 1 part by weight of the release material.
05 to 1.0 part by weight, more preferably 0.01 to 0.4
The range is 0 parts by weight.

In the toner composition for developing an electrostatic latent image according to the present invention, carbon black, nigrosine, aniline blue,
Calcoil Blue, Chrome Yellow, Ultramarine Blue, Dupont Oil Red, Quinoline Yellow, Methylene Blue Chloride, Phthalocyanine Blue, Malachite Green Oxalate, Lamp Black, Rose Bengal, C.I. I. Pigment Red 48: 1, C.I.
I. Pigment Red 122, C.I. I. Pigment
Red 57: 1, C.I. I. Pigment Yellow 97,
C. I. Pigment Yellow 12, C.I. I. Pigment Blue 15: 1, C.I. I. Pigment Blue 1
Pigments such as 5: 3 can be exemplified as typical ones.

The binder resin, which is another component of the toner particles, includes styrenes such as styrene and chlorostyrene, monoolefins such as ethylene, propylene, butylene and pentylene, dienes such as butadiene and isoprene, and the like. Vinyl acetate, vinyl propionate, vinyl butyrate,
Vinyl esters such as vinyl benzoate, methyl acrylate, ethyl acrylate, butyl acrylate, octyl acrylate, dodecyl acrylate, phenyl acrylate,
Α-methylene aliphatic monocarboxylic acid esters such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, dodecyl methacrylate, vinyl methyl ether,
Examples thereof include homopolymers or copolymers of vinyl ethers such as vinyl ethyl ether and vinyl butyl ether, and vinyl ketones such as vinyl methyl ketone, vinyl hexyl ketone, and vinyl isopropenyl ketone.

Typical binder resins include polystyrene resin, styrene-alkyl acrylate copolymer, styrene-alkyl methacrylate copolymer, styrene-acrylonitrile copolymer, styrene-butadiene copolymer,
Styrene-maleic anhydride copolymer, polyethylene resin and polypropylene resin can be mentioned. Furthermore,
Polyester resin, polyurethane resin, epoxy resin,
Silicone resin, polyamide resin, modified rosin, paraffins, waxes and the like can also be mentioned.

Among these binder resins, it is particularly effective to use a polyester resin as the binder resin. The polyester resin can be produced by reacting a polyhydroxy compound with a polybasic carboxylic acid or a reactive derivative thereof. Examples of the polyvalent hydroxy compound constituting the polyester resin include ethylene glycol, diethylene glycol, triethylene glycol, and 1,2-
Diols such as propylene glycol, 1,3-propylene glycol, 1,4-butanediol, and neopentylene glycol; bisphenol A alkylene oxides such as hydrogenated bisphenol A, polyoxyethylenated bisphenol A, and polyoxypropylene bisphenol A Additional compounds, other dihydric alcohols, and dihydric phenols such as bisphenol A are exemplified.

The polybasic carboxylic acids include, for example, malonic acid, succinic acid, adipic acid, sebacic acid, alkyl succinic acid, maleic acid, fumaric acid, mesaconic acid,
Reactive acid derivatives such as citraconic acid, itaconic acid, glutaconic acid, cyclohexanedicarboxylic acid, phthalic acid, isophthalic acid, terephthalic acid, and other divalent carboxylic acids, or acid anhydrides, alkyl esters, and acid halides thereof; Can be

In addition to these divalent carboxylic acids, in order to make the polymer non-linear to the extent that insolubles in tetrahydrofuran do not occur, a trivalent or higher polyhydric hydroxy compound and / or a trivalent or higher polybasic carboxylic acid may be used. An acid can be added.

Examples of the trivalent or higher polyhydroxy compound include sorbitol, 1,2,3,6-hexanetetraol, 1,4-sorbitan, pentaerythritol, 1,2,4-butanetriol, 2,5-pentanetriol, glycerin, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane,
1,3,5-trimethylolbenzene and the like can be mentioned. Examples of the tribasic or higher polybasic carboxylic acid include 1,2,4-butanetricarboxylic acid and 1,2,4-
Examples thereof include cyclohexanetricarboxylic acid, 1,2,4-benzenetricarboxylic acid, 1,2,5-benzenetricarboxylic acid, and 2,5,7-naphthalenetricarboxylic acid.

Among these polyester resins, a linear polyester resin comprising a polycondensate containing bisphenol A and an aromatic polycarboxylic acid as main monomer components can be particularly preferably used. Also, the physical properties of polyester resin
Softening point 90-150 ° C, glass transition point 50-70 ° C, number average molecular weight 2000-6000, weight average molecular weight 800
It is preferable to show 0 to 15000, an acid value of 5 to 30, and a hydroxyl value of 5 to 40.

In the present invention, the content of the colorant in the toner particles is preferably in the range of 1 to 8 parts by weight based on 100 parts by weight of the binder resin. When the content of the colorant is less than 1 part by weight, the coloring power is weakened, and when the content is more than 8 parts by weight, the transparency of the toner is deteriorated.

In the first toner composition for developing an electrostatic latent image of the present invention, fine particles of a release material coated with the above resin are dispersed in a binder resin which is a component of the above toner particles. It is contained in an amount of 1 to 30% by weight, preferably 2 to 15% by weight, based on the toner composition.
Range.

The first toner composition for developing an electrostatic latent image may be produced by a method of melting and kneading fine particles of a release material coated with a binder resin, a colorant, and a resin. In the process of producing a so-called polymerized toner, such as suspension polymerization or emulsion polymerization of a binder resin forming monomer, it can also be produced by adding fine particles of a release material coated with the resin together with a colorant. . In producing the toner composition for developing an electrostatic latent image, if necessary, a charge control agent,
Additives such as a fixing aid, a fluidity improver, a release agent and a cleaning aid can also be blended.

More specifically, the melt-kneading treatment can be performed by using various types of heating kneaders. As the heating kneader, a three-roll type, a single screw type, a twin screw type, or a Banbury mixer type can be used. After the melt-kneading treatment, the melt-kneaded product is cooled and then pulverized in a pulverizing step. As a pulverizer used in the pulverization step, a pulverizer of a collision plate type, a jet type or the like is used. For example, a micronizer, an ulmax, a jet-O-miser is used for a collision plate type, and a KTM (Krypton), a turbo mill or the like is used for a jet type. In addition, a construction type jet mill or the like can be used as having both of these characteristics. Classification may be performed in order to make the particle size of the pulverized toner particles uniform. For that, Turbo Classifier, Elbow Jet,
Other known materials can be used. It is preferable that the toner particles have an average particle diameter of about 30 μm or less, and more preferably 5 to 20 μm.

In the second toner composition for developing an electrostatic latent image of the present invention, fine particles of a release material coated with the above resin are added to and mixed with the toner particles as an external additive. The toner particles are composed of at least a binder resin and a colorant, but have been described in the first electrostatic latent image developing toner composition except that fine particles of a release material coated with the resin are not added. It can be manufactured in a similar manner. The compounding amount of the fine particles of the releasable material added as an external additive to the toner particles is in the range of 0.5 to 5% by weight, more preferably 0.5 to 3% by weight of the toner composition. Is set to In addition, various external additives may be added to the toner composition of the present invention for the purpose of improving powder fluidity, developability, transferability, cleaning properties, and the like. For example, silica, alumina, titania, or other known materials may be added.
The external additive can be attached to the surface of the toner particles by, for example, a high-speed mixer. Specifically, the toner particles may be mixed with an external additive using a Henschel mixer, a V-type blender, or the like.

The first and second electrostatic latent image developing toner compositions of the present invention are used as an electrostatic latent image developer.
It may be used as a one-component developer without using a carrier,
Alternatively, it may be used as a two-component developer using a carrier. However, use as a two-component developer is preferred. The carrier when used as a two-component developer is not particularly limited as long as it is a known carrier, and examples thereof include an iron powder-based carrier, a ferrite-based carrier, a surface-coated ferrite carrier, and a magnetic powder-dispersed carrier. The compounding ratio of the toner composition for developing an electrostatic latent image to the carrier is preferably in the range of 1 to 10% by weight of the toner with respect to the carrier.

In the image forming method of the present invention, the above-described electrostatic latent image developer is used as a developer. The image forming method includes a known method for forming an electrostatic latent image to obtain a fixed toner image. Forming an electrostatic latent image on a latent image holding member, developing the electrostatic latent image using a developer, and transferring the developed toner image onto a transfer member. An image forming method including a fixing step of heating and fixing a toner image on a transfer member can be used.

Next, the action of the fine particles of the release material coated with the resin in the present invention will be described. Usually, the release material is sheared by thermal stimulus or mechanical external force during kneading or polymerization process of the polymerized toner, and has various domain shapes, domain diameters, and number of domains. Such a domain form of the releasable material in the toner is conventionally known, and has a great influence on the fixing characteristics of the toner to the transfer material, the toner fluidity, and the toner storability. Therefore, conventionally, in order to control the domain morphology, a release material, a binder resin, a production method, and a dispersing aid such as a compatibilizer have been studied. The toner composition for developing an electrostatic latent image according to the first aspect of the present invention does not have such a problem, for example, the toner composition has a problem or adversely affects a toner characteristic, for example, a charging characteristic. That is, in the first electrostatic latent image developing toner composition of the present invention, since the fine particles of the releasable material are covered with the resin, the fine particles exist as so-called domains in the toner, In addition, the particle shape and the particle diameter are domain forms in the toner. Therefore, the first electrostatic latent image developing toner composition of the present invention can control the domain form of the releasable material in the toner. It is possible to improve the fixing characteristics without limiting the manufacturing conditions. Further, in the electrostatic latent image developing toner composition of the present invention, since the fine particles of the releasable material are in the form of particles coated with a resin, even if the fine particles are exposed on the surface of the toner particles, There is no adverse effect on the toner fluidity and toner storability.

In the toner composition for developing an electrostatic latent image according to the second aspect of the present invention, fine particles of a releasable material coated with a resin are added as an external additive. The toner is not exposed to the surface and does not adversely affect the fluidity of the toner and the storability of the toner, and the amount of the release material contained in the toner composition can be significantly reduced. It is possible to reduce the domain diameter and the number of the release materials. Generally, the releasable materials and the toner binder resin do not have the same refractive index, and many of the releasable materials have crystallinity, which is inferior in light transmittance. In a color image, if the light transmittance of the color toner is deteriorated, the color developability is deteriorated and darkening occurs, or the formed OHP image is darkened. When the composition is used, the total amount of the release material added to the toner can be reduced, so that the effect can be more effectively exerted on the color toner. Further, in the case of a color toner, when gloss is required for a fixed image, it is necessary to use a resin having a low melting point and a low glass transition point as a binder resin, and accordingly the toner fluidity deteriorates. When the first and second electrostatic latent image developing toner compositions of the present invention are used, the disadvantage in this case is avoided.

Further, when the resin to be coated is polyurea or polyurethane, these resins are heat-responsive, that is, by applying heat of about 130 to 150 ° C., they become flexible in structure and are included in the resin. The releasable material easily flows out (even if the resin film is not mechanically broken). Therefore, those coated with fine particles of the release material with polyurea or polyurethane have the same toughness against mechanical pressure shock as compared with those containing fine particles of the release material with other resins. However, when the resin film does not break due to pressure when passing through the heat fixing roll together with the toner, the release material in the resin exudes,
We show the effect more effectively.

[0043]

EXAMPLES Example of Preparation of Fine Particles of Releasable Material Coated with Resin (Fine Particles a) Carnauba wax having a melting point of 83 ° C. (acid value 8
mg / g, molecular weight 520) 100 g of ethyl acetate was added to 30 g, and the mixture was placed in a pressure vessel, and the temperature was set to 120 ° C.
By stirring and quenching, a wax suspension having an average particle diameter of 0.5 μm was obtained. 5 g of Takenate D110
N (adduct type of xylene diisocyanate, manufactured by Takeda Pharmaceutical Co., Ltd.) was added, and the mixture was stirred at 40 ° C. for 30 minutes. Then, 2 g of ethylenediamine was added, and the mixture was further stirred for 30 minutes to form a polyurea film around the wax. The mixture was filtered, freeze-dried and powdered to obtain fine particles. The average particle diameter of the obtained fine particles was 0.7 μm.

(Fine particles b) Microcrystalline wax having a melting point of 64 ° C. (acid value = about 0, molecular weight = about 450) 30
to 100 g of methyl ethyl ketone (MEK),
The mixture was placed in a pressure vessel, the temperature was set to 100 ° C., and stirring and quenching were performed to obtain a wax suspension having an average particle diameter of 0.3 μm. To this, 4 g of torillin diisocyanate was added and stirred at 30 ° C. for 30 minutes to give butanediol 1.
5 g was added and the mixture was further stirred for 60 minutes to form a polyurethane film around the wax. After filtering the mixed solution, it was vacuum-dried to obtain a powder, and the fine particles were taken out as a powder. The average particle size of the obtained fine particles was 0.5 μm.

(Fine particles c) 100 g of carnauba wax having a melting point of 83 ° C. (acid value: 8 mg / g, molecular weight: 520)
g of ethyl acetate, and put in a pressure vessel.
° C, stirring, quenching, average particle size 0.5μm
Wax suspension was obtained. 3 g of Takenate D110N (adduct type of xylene diisocyanate, manufactured by Takeda Pharmaceutical Co., Ltd.) was added thereto, and the mixture was stirred at 40 ° C. for 30 minutes.
After stirring for a minute, a polyurea film was formed around the wax. The mixture was filtered, freeze-dried and powdered to obtain fine particles. The average particle diameter of the obtained fine particles was 0.7 μm.

(Fine particles d) Microcrystalline wax having a melting point of 64 ° C. (acid value = about 0, molecular weight = about 450) 30
Then, 100 g of MEK is added to the mixture, and the mixture is placed in a pressure-resistant container.
A wax suspension of 3 μm was obtained. To this was added 3 g of tolylene diisocyanate, stirred at 30 ° C. for 30 minutes, added 1 g of butanediol, and further stirred for 60 minutes to form a polyurethane film around the wax. After filtering the mixed solution, it was vacuum-dried to obtain a powder, and the fine particles were taken out as a powder. The average particle diameter of the obtained fine particles is
It was 0.5 μm.

Example 1 90% by weight of linear polyester resin (linear polyester obtained from terephthalic acid / bisphenol A / ethylene oxide adduct / cyclohexanedimethanol: Tg = 62 ° C., Mn = 4,000, Mw = 35, 000, acid value = 12, hydroxyl value = 25) Magenta pigment (CI Pigment Red 57) 3% by weight Fine particles a 7% by weight The above mixture was kneaded with an extruder (TEM48, manufactured by Toshiba Machine Co., Ltd.). Kneading, feed rate 100kg
/ Hr, rotor speed 300 rpm, barrel setting temperature 110 ° C. After the obtained kneaded material is pulverized by a jet mill, it is classified by an air classifier to obtain an average particle diameter d50 =
8 μm magenta toner particles were obtained. The silica (R
972, manufactured by Nippon Aerosil Co., Ltd.) in an amount of 0.5% by weight with a Henschel mixer to obtain a magenta toner.

Example 2 A magenta toner having a d50 = 7.5 μm was obtained in the same manner as in Example 1 except that the fine particles a were changed to the fine particles b. Example 3 A magenta toner having d50 = 8.0 μm was obtained in the same manner as in Example 1, except that the linear polyester resin was changed to 85% by weight and the fine particles a were changed to 13% by weight.

Comparative Example 1 In Example 1, 97% by weight of the linear polyester resin was used.
And the same treatment is performed except that the fine particles a are removed.
A 7.5 μm magenta toner was obtained. Comparative Example 2 In Example 1, the fine particles a were converted to microcrystalline wax having a melting point of 64 ° C. (acid value = about 0, molecular weight = about 450).
The magenta toner having d50 = 7.5 .mu.m was obtained in the same manner except that the magenta toner was changed. Comparative Example 3 In Comparative Example 2, 3 microcrystalline waxes were used.
In the same manner as above, except that the amount of the linear polyester resin was changed to 94% by weight, a magenta toner having d50 = 7.8 μm was obtained.

Examples 4 to 6 and Comparative Examples 4 to 6 The magenta of Examples 1 to 3 and Comparative Examples 1 to 3 was applied to 100 parts of a carrier in which a styrene-methyl methacrylate copolymer was coated on a ferrite having a particle diameter of 50 μm. 6 parts of the toner was added and mixed to obtain a developer.

(1) Offset Property Using the developers of Examples 4 to 6 and Comparative Examples 4 to 6, a commercial copying machine (A-color 630, manufactured by Fuji Xerox Co., Ltd.) was used to transfer paper of A4 size. 5cm in height, 4c in width
m of solid unfixed toner image was prepared. At this time, a toner image was prepared such that the toner amount was 0.6 to 0.8 mg / cm ² . Next, the fixing roll temperature is set so that the fixing roll temperature can be freely set and the fixing roll temperature can be monitored.
Using a modified roller 630, the test was performed in a state where the supply of the release agent oil to the fixing roll was stopped and the release agent oil was not substantially present on the surface of the fixing roll. That is, the surface temperature of the fixing roll was changed stepwise, and the transfer paper holding the unfixed toner image was processed at each surface temperature to fix the unfixed toner image. At this time, observation was made as to whether or not toner stains occurred in the margins, and a temperature region where no stains occurred was defined as a non-offset temperature region. Also,
The value between the maximum value and the minimum value in the non-offset temperature region was defined as the non-offset temperature width.

(2) Fluidity For the magenta toners of Examples 1 to 3 and Comparative Examples 1 to 3, JIS K51 was used as an index indicating the fluidity of the toner.
01, and the apparent density was measured. (3) Storage stability Regarding the magenta toners of Examples 1 to 3 and Comparative Examples 1 to 3, 20 g of the toner was put in a polyethylene bottle having a volume of 150 cc, and stored in a 50 ° C constant temperature bath for 24 hours. After cooling to room temperature, remove the toner from the bottle, observe the fusion state (blocking) between the toner particles, and mark a mark that does not cause any fusion at all. Is marked with x.

Table 1 shows the results of these tests. The amount of the surface wax (the amount of the release material on the surface of the toner particles) is
ESCA (XPS) [Electron Spectr
oscopy for Chemical Analysis
sis (X-ray Photoelectron S
pectroscopy)] to determine the ratio of the number of elements present in the surface layer (within 5 nm) of the toner particles, and then determine the ratio of the elements present for each of the constituent compounds such as the binder resin, wax, and magnetic powder, which are the toner components, These values are obtained by calculating the amount of wax present in the toner surface layer by weight ratio.

[0054]

[Table 1]

As is clear from the test results in Table 1, in the case of the magenta toners of Examples 1 to 3 of the present invention, no offset occurs in the developer using the magenta toner, and the non-offset temperature region is low. From a temperature to a high temperature, it was confirmed that the temperature range maintained a practically sufficient range of 75 to 90 ° C. It was also confirmed that there was no problem in fluidity and storage stability. In contrast, in the case of Comparative Example 1, since no release material was used,
Although the fluidity and the storage stability are sufficient, the non-offset temperature range is very narrow, and there is a problem. In the case of Comparative Example 2, the non-offset temperature range was wide and sufficient, but the amount of surface wax was high, so that the fluidity and storage stability were at a level at which problems occurred. In the case of Comparative Example 3, although the fluidity was slightly better than that of Comparative Example 2, there was a problem in storage stability, and the non-offset temperature range was not sufficient.

A commercially available copying machine (A-color 630, manufactured by Fuji Xerox Co., Ltd.) using the developers of Examples 4 to 6 above
, Continuous copying up to 10,000 sheets was performed. Table 2 shows the results. This test was performed on A-color 63
The test was performed in a state where the supply of the release agent oil to the fixing roll of No. 0 was stopped. Note that the continuously copied manuscript is A4 with 6% black.
Paper is used, image density is X-write 404, fog is a color difference meter manufactured by Nippon Denshoku Co., Ltd., and charge amount is a value obtained by image analysis using CSG (charge spectrograph method).

[0057]

[Table 2]

Example 7 97% by weight of linear polyester resin (linear polyester obtained from terephthalic acid / bisphenol A / ethylene oxide adduct / cyclohexanedimethanol; Tg = 62 ° C., Mn = 4,000, Mw = 35, 000, acid value = 12, hydroxyl value = 25) Magenta pigment (CI Pigment Red 57) 3% by weight The above mixture was kneaded with an extruder, pulverized with a jet mill, and dispersed with a wind classifier. As a result, magenta toner particles having a D50 of 8 μm were obtained.

In the magenta toner particles, fine particles c1.
5% by weight and 0.4% by weight of silica (trade name: R972, manufactured by Nippon Aerosil Co., Ltd.) were added, and the mixture was treated with a Henschel mixer to obtain a magenta toner composition.

Example 8 A magenta toner composition was obtained in the same manner as in Example 7, except that the fine particles c were changed to the fine particles d. Example 9 A magenta toner composition was obtained in the same manner as in Example 7, except that the addition amount of the fine particles c was changed to 4% by weight.

Comparative Example 7 A magenta toner composition was obtained in the same manner as in Example 7, except that the addition amount of the fine particles c was changed to 6% by weight. Comparative Example 8 The same linear polyester resin as in Example 7 90% by weight Carnauba wax (acid value 8 mg / g, molecular weight 520) 7% by weight Magenta pigment (CI Pigment Red 57) 3% by weight D50 = 8 using the same procedure as in Example 7.
μm toner particles were obtained. Further, 0.5% by weight of silica (R972, manufactured by Nippon Aerosil Co., Ltd.) was added to the toner particles, and the mixture was treated with a Henschel mixer to obtain a magenta toner composition. Comparative Example 9 94% by weight of linear polyester resin as in Example 7 3% by weight of carnauba wax (acid value 8 mg / g, molecular weight 520) 3% by weight of magenta pigment (CI pigment red 57) 3% by weight of the above mixture D50 = 8 using the same procedure as in Example 7.
μm toner particles were obtained. Further, 0.5% by weight of silica (R972, manufactured by Nippon Aerosil Co., Ltd.) was added to the toner particles, and the mixture was treated with a Henschel mixer to obtain a magenta toner composition.

Examples 10 to 12 and Comparative Examples 10 to 12 100 parts of a carrier in which a styrene-methyl methacrylate copolymer was coated on a ferrite having a particle diameter of 50 μm was used in Examples 7 to 9 and Comparative Examples 7 to 9. 6 parts of the magenta toner composition was added and mixed to obtain each developer.

The magenta toner compositions of Examples 7 to 9 and Comparative Examples 7 to 9 and Examples 10 to 1 using the same.
2 and the developers of Comparative Examples 10 to 12 were evaluated for offset properties, fluidity, and storage stability in the same manner as described above. Table 3 shows the results.

[Table 3]

As is clear from the test results in Table 3, in the case of the magenta toner compositions of Examples 7 to 9 of the present invention, no offset occurs in the developer using the same, and the non-offset temperature region is From low to high temperatures,
It was confirmed that the temperature range also maintained a practically sufficient range of 85 to 100 ° C. It was also confirmed that there was no problem in fluidity and storage stability.
On the other hand, in the case of Comparative Example 7, offset was not generated from a low temperature to a high temperature, which was sufficient, but there was a problem that the apparent density in fluidity was small. Comparative Example 8
In the case of (1), it was confirmed in the storage stability test that the toner was fused and had a problem. Further, in the case of Comparative Example 9, the non-offset temperature width was as narrow as 60 ° C., and the apparent density due to the fluidity was small, causing a problem.

Using the developers of Examples 10 to 12 above, continuous copying of up to 10,000 sheets was performed with a commercially available copying machine (A-color 630, manufactured by Fuji Xerox Co., Ltd.).
Table 4 shows the results. This test is based on A-color
630 was performed with the supply of the release agent oil to the fixing roll stopped. In addition, the black part of the continuous copied original is 6%.
A4 paper, the image density is X-write 404, the fog is a color difference meter manufactured by Nippon Denshoku Co., Ltd., and the charge amount is a value obtained by CSG (charge spectrograph) image analysis.

[0066]

[Table 4]

[0067]

The toner composition for developing an electrostatic latent image of the present invention can maintain a sufficient non-offset temperature range, can be fixed at a low temperature, and has excellent fixing strength and storage stability. The effect is that a large number of copies can be obtained with a sufficient image density. Therefore, when a developer using the toner composition for developing an electrostatic latent image of the present invention is applied to a copying machine, a printer, or the like, power consumption can be reduced, machine cost can be reduced by lowering roll pressure, and copying can be performed. This has the effect of increasing the speed. Further, when applied to a full-color copying machine, there is no need to supply a releasing liquid to the surface of the heat-fixing roller, and a device for supplying the releasing liquid can be omitted. Thus, there is an effect that an image without stickiness can be obtained without adhesion of the releasing liquid.

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Atsuhiko Eguchi 1600 Takematsu, Minamiashigara, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd. (72) Inventor Tetsuya Taguchi 1600 Takematsu, Minamiashigara City, Kanagawa Prefecture Inside Fuji Xerox Co., Ltd.

Claims (5)

[Claims] 1. An electrostatic latent device comprising at least a binder resin, a colorant, and fine particles of a release material coated with a resin, wherein the fine particles are dispersed in the binder resin. An image developing toner composition. 2. An electrostatic latent image developing method, comprising mixing toner particles comprising at least a binder resin and a colorant with fine particles of a release material coated with a resin as an external additive. Toner composition. 3. An electrostatic latent image developer comprising the electrostatic latent image developing toner composition according to claim 1 and a carrier. 4. An electrostatic latent image developer comprising the electrostatic latent image developing toner composition according to claim 2 and a carrier. 5. A step of forming an electrostatic latent image on a latent image holding member, a step of developing the electrostatic latent image using a developer, a step of transferring the developed toner image onto a transfer member, 5. An image forming method comprising a fixing step of heating and fixing a toner image on a body, wherein the electrostatic latent image developer according to claim 3 or 4 is used as the developer.