JP3038465B2 - Method for producing capsule toner for heat and pressure fixing and capsule toner - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot and pressure fixing capsule toner used for developing an electrostatic latent image formed in an electrophotographic method, an electrostatic printing method, an electrostatic recording method and the like, and a method for producing the same.

[0002]

2. Description of the Related Art Conventional electrophotography is disclosed in U.S. Pat. Nos. 2,976,691 and 235,780.
As described in the specification of JP-A-9, etc., an electrically latent image is formed by uniformly charging the photoconductive insulator layer, then exposing the layer, and dissipating the charge on the exposed portion. The latent image was visualized by adhering a fine powder having a colored charge called toner to the latent image (development step), and the obtained visible image was transferred to a transfer material such as transfer paper. After (transfer step), permanent fixing is performed by heating, pressure or other appropriate fixing method (fixing step). As described above, the toner must have functions required not only in the developing step but also in each of the transferring step and the fixing step.

In general, a toner receives a mechanical frictional force due to a shearing force and an impact force received during a mechanical operation in a developing device.
It deteriorates during copying of thousands to tens of thousands of sheets. In order to prevent such deterioration of the toner, a tough resin having a large molecular weight that can withstand mechanical frictional force may be used, but these resins generally have a high softening point, and are not used in oven fixing, which is a non-contact fixing method. Fixing is not performed sufficiently due to poor thermal efficiency. Also, in the thermal pressure fixing method using a heat roller, which is a widely used contact fixing method due to its high thermal efficiency, it is necessary to increase the temperature of the heat roller, which causes problems such as deterioration of the fixing device and curling of paper. Invite. Further, when such a resin is used, the pulverizability is poor, so that when producing a toner, the production efficiency is significantly reduced. Therefore, a resin having a very high degree of polymerization and a softening point of the binder resin cannot be used.

On the other hand, a heat pressure fixing method using a heat roller or the like has a remarkably high thermal efficiency and is widely used from a low speed to a high speed. However, when a heat roller surface and a toner image surface come into contact with each other, toner is applied to the heat roller surface. The so-called offset phenomenon, which is adhered and transferred to the subsequent transfer paper or the like, is likely to occur. In order to prevent this phenomenon, the surface of the heating roller is processed with a material having excellent release properties, and furthermore, a release agent such as silicone oil is applied to the surface. , And it is easy to cause high cost and equipment trouble.

Further, Japanese Patent Publication No. 57-493 and Japanese Patent Application Laid-Open No.
No. 6, JP-A-57-37357 discloses a method of improving the offset phenomenon by asymmetric and cross-linking the resin, but the fixing property is not improved.

In general, since the minimum fixing temperature is between the low-temperature offset and the high-temperature offset, the usable temperature range is between the minimum fixing temperature and the high-temperature offset. Increasing the temperature can lower the fixing temperature in use and also widen the usable temperature range, which can save energy, achieve high-speed fixing, and prevent paper curling. For this reason, a toner having good fixability and anti-offset property is always desired.

Hitherto, there has been proposed a technique for achieving low-temperature fixability by using a capsule toner composed of a core material and an outer shell provided so as to cover the surface of the core material, as the toner.

[0008] Among them, when a low melting point wax or the like which is easily plastically deformed is used as a core material (US Pat. No. 3,269,626, Japanese Patent Publication No. 46-15876), fixing can be performed only by pressure, but fixing strength is low. Poor, limited in use. Further, when a liquid material is used as the core material, the shell material may be broken in the developing device and stain the inside of the device, and it is difficult to adjust the strength of the shell material.

Therefore, when used alone as a core material for heat and pressure fixing, blocking occurs at a high temperature, but a resin having a low glass transition point which improves the fixing strength is used, and anti-blocking properties and the like are imparted to the outer shell. For this purpose, a capsule toner for heat roller fixing in which a high melting point resin wall is formed by interfacial polymerization has been devised.

[0010] Such a capsule toner is disclosed in
JP-56352-A and further improved capsule toners have been proposed (JP-A-58-205162, JP-A-58-205163, JP-A-63-128357 and JP-A-63-128357).
No. 128358, No. 63-128359, No. 63-128360, No. 63-128361, No. 63-128362), but because the manufacturing method is a spray-drying method, a burden is imposed on manufacturing equipment, Since the shell material is not devised, the performance of the core material has not been fully exploited.

Therefore, a capsule toner using a compound having a heat dissociation property as a shell material (Japanese Patent Application Laid-Open No. 4-212169).
Also, a capsule toner using an amorphous polyester as a shell material (Japanese Patent Application No. 4-259088) has been proposed. In the case of manufacturing these capsule toners, a method of suspending a polymerizable monomer in a dispersion medium and forming the outer shell by interfacial polymerization or an in situ method in consideration of shortening of a process, simplification of equipment, and the like. And the above-mentioned encapsulated toner is produced by these methods.

On the other hand, conventionally, a conductive substance has been contained in the core material of the capsule toner for the purpose of improving the cleaning property and stabilizing the charge, and a charge control agent has been provided for the purpose of controlling the charge to either positive or negative polarity. In addition, a wax component is added for the purpose of improving the offset resistance, a coloring material pigment is used for the colorant, and a magnetic powder is added for the purpose of imparting magnetism to the toner.

[0013] Such additives are generally solid and often do not dissolve in the polymerizable monomer. In addition, the charge control agent, the coloring material pigment and the like usually have particles in the form of aggregates. For this reason, when producing a toner by the suspension polymerization method, the polymerizable monomer and the above-mentioned additive are sufficiently crushed into particles using a disperser such as a ball mill and a sand stirrer, and then solid-liquid dispersed. A method of producing a toner by performing polymerization is used. However, the charge control agent originally added for the purpose of stabilizing the charge, and additives such as a conductive substance added for the purpose of improving the cleaning property, the effect is greatly exhibited by being present near the toner surface, When the additive is dispersed by the above-described dispersion method, there is a problem that the effect is not exhibited because the additive is easily taken into the toner and hardly exists on the toner surface.

To solve such a problem, Japanese Patent Laid-Open Publication No. 1-1
JP-A-85652, JP-A-1-185659 and JP-A-1-185665 disclose that an additive or a resin fine particle containing an additive is fixed on a toner surface to a toner obtained by a suspension polymerization method. A manufacturing method has been disclosed in which an additive is present on the surface of a toner to impart its function. However, such a manufacturing method requires cost for manufacturing equipment, poor manufacturing stability due to poor dispersibility of the additives, and furthermore, not all additives are sufficiently firmly fixed on the toner surface. There was also a problem that a sufficient amount of the additive was released and the inside of the machine was contaminated.

The present invention has been made in view of the above circumstances, and an object of the present invention is to allow an additive that does not dissolve in a polymerizable monomer to exist near the toner surface with good dispersibility and good efficiency. Another object of the present invention is to provide a capsule toner for heat and pressure fixing capable of suitably exhibiting the function of an additive, free from in-machine contamination, and capable of fixing at a low temperature, and a method for producing the same.

[0016]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems, and as a result, have found that a resin in which various additives such as a conductive substance are dispersed is used for the outer shell of a capsule toner. Finds that the above problems can be solved,
The present invention has been completed.

That is, the gist of the present invention is as follows: (1) A heat-pressure fixing capsule comprising a heat-meltable core material containing at least a thermoplastic resin and an outer shell provided so as to cover the surface of the core material. In the method for producing a toner, by performing in situ polymerization using a resin in which one or more additives selected from the group consisting of a conductive substance, a charge control agent, a wax component, a coloring material pigment, and a magnetic powder are dispersed in advance. A method for producing a capsule toner for heat and pressure fixing, wherein the surface of a core material is coated with the resin to form an outer shell in which the additive is dispersed; (2) a main component of the resin constituting the outer shell Is an amorphous polyester, (3) the production method according to the above (1), wherein the amorphous polyester comprises 1
At least one kind of dihydric alcohol monomer and at least one kind of divalent carboxylic acid monomer, further, at least a trivalent or more polyhydric alcohol monomer and / or a trivalent or more polyvalent carboxylic acid monomer And a glass transition point of 50 to 80 ° C. and an acid value of 3 to 50 (KOH mg
/ G) in which the (2) method of manufacturing described, parallel Beauty to (4) above (1) to (3) for heat-and-pressure fixing encapsulated toner obtainable by the method according any concerns.

The capsule toner for heat and pressure fixing of the present invention comprises:
In a capsule toner for heat and pressure fixing comprising a heat-fusible core material containing at least a thermoplastic resin and an outer shell provided so as to cover the surface of the core material, various additives are dispersed in the outer shell resin. It is characterized by becoming. Here, as the various additives, one or more selected from the group consisting of a conductive substance, a charge control agent, a wax component, a coloring material pigment, and a magnetic powder are used. That is, these are 2
More than one species may be used in combination.

In the present invention, since the additive usually dispersed in the core material of the capsule toner is dispersed in the outer shell resin, the function of the additive is suitably exhibited as described below. be able to. Therefore, in the present invention, additives appropriately selected within a range not losing the function as the outer shell may be dispersed in the outer shell resin, and other additives can be dispersed in the core material. Specifically, the distribution of various additives includes, for example, the following embodiments, but the present invention is not limited thereto.

A Core material: charge control agent, wax component, color material pigment, magnetic powder Shell material: conductive material b Core material: conductive material, charge control agent, wax component, magnetic powder Shell material: color material pigment c Core material: Conductive substance, charge control agent, wax component, colorant pigment Shell material: magnetic powder d Core material: Charge control agent, wax component, colorant pigment Shell material: Conductive substance e Core material: Conductive substance, Charge control agent, wax component Shell material: color material pigment f Core material: conductive material, charge control agent, color material pigment, magnetic powder Shell material: wax component g Core material: charge control agent, wax component, magnetic powder shell material : Conductive substance, colorant pigment h Core material: conductive substance, colorant pigment, magnetic powder Shell material: charge control agent, wax component i Core material: charge control agent, colorant pigment, magnetic powder Shell material: conductive Substance, wax component

First, these additives will be described in detail below.

The conductive material (low-resistance material) that can be used in the present invention is not particularly limited as long as it has a resistivity of 10 ⁻³ to 10 ³ Ω · cm. Iron, tetraacid iron oxide, tin oxide, titanium oxide, or the like can be used. Among them, carbon black has a small particle size, and thus can be suitably used in the present invention. The carbon black is not particularly limited as long as it is produced by a normal production method such as a channel method and a furnace method.

The pH value of these carbon blacks is usually from 3.0 to 10, preferably from 5.0 to 9.0, and the amount of loss on evaporation is usually 5% or less, preferably 3% or less. Is done. In general, the resin has a high resistivity of 10 ¹² to 10 ¹⁷ Ωcm because the resin is inherently electrically insulating, but the resin has a resistivity of 10 ⁶ to 10 by dispersing a conductive substance as in the present invention. It becomes ¹¹ Ωcm.

Conventionally, the toner obtained by the suspension polymerization method has a shape close to a sphere, and when the copying speed and printing speed are high, even if the untransferred toner remaining on the photoreceptor is cleaned using a blade, And the toner has a strong adhesive force, the untransferred toner is not completely removed, and black streaks remain on the final image.

One of the causes of the increase in the adhesion is considered to be an increase in the electrostatic adhesion due to the high electric resistance of the toner. That is, in the capsule toner manufactured by the above-mentioned polymerization method, the electric resistance of the toner tends to increase because the toner surface is covered with the shell resin.

As a method for reducing the electric resistance of such a toner, a method of mechanically attaching a conductive substance such as carbon black on the surface of the toner as described above is known. However, in such a method, there is a problem that the attached conductive substance is peeled off by stirring in the developing device, thereby causing contamination in the device. Further, it is difficult to control the resistance. Particularly, when the toner resistance is less than 10 ⁵ Ωcm, it becomes difficult to electrostatically transfer the developed toner to plain paper by corona transfer, bias transfer, or the like. was there.

Thus, as in the present invention, by using a resin in which a conductive substance is dispersed in advance as an outer shell, it becomes possible to control the electric resistance of the surface of the capsule toner obtained by the polymerization method, and to apply the untransferred toner. Even if the copying speed and the printing speed are high by lowering the adhesion, it can be completely removed by blade cleaning to prevent the occurrence of black streaks.

In the capsule toner for heat and pressure fixing according to the present invention, the conductive substance is dispersed in the outer shell resin. More specifically, the conductive substance is not usually exposed on the outer shell surface. It is dispersed all or part from the vicinity of the surface of the shell to the vicinity of the interface between the outer shell and the core material. in this way,
In the present invention, since the conductive substance is present in the outer shell resin and does not usually come out on the outer shell surface, the conductive substance is coated on the toner surface, or the conductive substance is contained only in the core material of the capsule toner. Is clearly distinguished from the conductive toner containing the same.

The dispersion concentration of the conductive substance is usually 5 to 50 parts by weight, preferably 10 to 40 parts by weight, based on 100 parts by weight of the outer shell resin. If the amount is less than 5 parts by weight, the resistance does not sufficiently decrease, and the effect on the cleaning property is small.

The charge control agents usable in the present invention include:
Both the following negatively chargeable charge control agents and positively chargeable charge control agents are exemplified. The negatively chargeable charge control agent is not particularly limited. For example, metal-containing azo dyes such as “Varifast Black 3804” and “Bontron S”
-31 "," Bontron S-32 "," Bontron S-
34 (all manufactured by Orient Chemical Co., Ltd.), "Eizen Spiron Black TRH", "Eizen Spiron Black T"
-77 "(both manufactured by Hodogaya Chemical Co., Ltd.) and metal complexes of copper phthalocyanine dyes and alkyl derivatives of salicylic acid, such as" Bontron E-81 "and" Bontron E-8 "
2, "Bontron E-85" (all manufactured by Orient Chemical Co., Ltd.), quaternary ammonium salts such as "COPY CHARGE NX"
VP434 "(manufactured by Hoechst), nitroimidazole derivatives and the like. Among these, preferred are "Eizen Spiron Black T-77",
"Eizen Spiron Black TRH".

The positively chargeable charge control agent is not particularly limited. For example, nigrosine dyes such as "Nigrosine Base EX", "Oil Black BS", "Oil Black SO", "Bontron N-01", "Bontron" N-07 "," Bontron N-09 "," Bontron N "
-11 "(all manufactured by Orient Chemical Co., Ltd.), such as a triphenylmethane dye containing a tertiary amine as a side chain, and a quaternary ammonium salt compound such as" Bontron P-51 "
(Orient Chemical Co., Ltd.), cetyltrimethylammonium bromide, "COPY CHARGE PX VP435" (Hoechst), polyamine resins such as "AFP-B" (Orient Chemical Co., Ltd.), imidazole derivatives and the like. Of these, preferred are "Bontron N-01", "Bontron N-07", "Bontron N-09", and "AFP-B".

Although it is possible to provide sufficient charge stability without adding a charge control agent to the heat-pressure fixing toner, a problem arises in that the toner is fogged on the photoreceptor particularly at high temperature and high humidity. was there. A method for stabilizing the charging property by adding a charge control agent to the toner to solve such a problem is known. However, if the added charge control agent is present near the center of the toner, it is not so effective. When the toner is present on the outermost surface of the toner, the charge control agent is transferred to the carrier, particularly in the case of a two-component developer, and the charge level of the toner is greatly reduced, so that a problem that the fog increases is likely to occur. If the charge control agent is added by the method of the present invention, the charge control agent exists in the vicinity of the toner surface because it is present in the outer shell resin, but does not precipitate on the toner outermost surface. A stable charge amount can be obtained, no transfer to the carrier occurs, and good results satisfying all conditions can be obtained.

The dispersion concentration of the charge control agent is usually 0.05 to 20 parts by weight of the charge control agent per 100 parts by weight of the shell resin.
Parts by weight, preferably 0.1 to 10 parts by weight. 0.0
If the amount is less than 5 parts by weight, image quality such as fogging tends to occur, and if it is more than 20 parts by weight, the charge amount level becomes too high and the image density tends to decrease.

Examples of the wax component usable in the present invention include polyolefin, fatty acid metal salt, fatty acid ester, partially saponified fatty acid ester, higher fatty acid, higher alcohol, paraffin wax, amide wax, polyhydric alcohol ester, silicone varnish, and the like. Any one or more kinds of offset inhibitors such as aliphatic fluorocarbons, silicone oils, microcrystalline waxes, and sasol waxes may be contained. Among these, preferred are polyolefin, silicone oil, microcrystalline wax and sasol wax.

Although the toner for heat and pressure fixing can have a sufficient offset resistance without adding a wax component, the copying speed and the printing speed are particularly high.
When the diameter of the fixing roller was large, the releasability from the fixing roller was poor, and nail marks were sometimes generated in a solid image.

To solve such a problem, a method of adding a wax component to the toner to improve the releasability is known. However, if the added wax component is present near the center of the toner, it is very difficult. If the effect does not appear, and if a wax component exists on the outermost surface of the toner, the problem that the wax component migrates to the photoreceptor and contaminates the print easily occurs.

When a wax component is added by the method of the present invention, the wax component is present in the outer shell resin.
Although present near the toner surface, it does not precipitate on the outermost surface of the toner, so that a large releasing effect can be obtained and no transfer to the photosensitive member occurs, and satisfactory results satisfying all conditions can be obtained.

The dispersion concentration of the wax component is usually
Wax component 5-100 per 100 parts by weight of outer shell resin
Parts by weight, preferably 10 to 70 parts by weight. When the amount is less than 5 parts by weight, the releasing effect is low, and when the amount is more than 100 parts by weight, contamination of the photoreceptor tends to occur.

As the coloring material pigment which can be used in the present invention, various kinds of organic or inorganic pigments and dyes as shown below can be used.

That is, examples of black pigments include carbon black, copper oxide, manganese dioxide, aniline black, and activated carbon. Examples of yellow pigments include yellow lead, 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, benzidine yellow G
R, quinoline yellow lake, permanent yellow NC
G, tartrazine rake and the like.

Examples of the orange pigment include red yellow lead, molybdenum orange, permanent orange GTR, pyrazolone orange, vulcan orange, indaslen brilliant orange RK, benzidine orange G, and indaslen brilliant orange GK. Red pigments include red iron, cadmium red, leadtan, mercury sulfide, quinacridone, cadmium, permanent red 4R, lithol red, pyrazolone red, watching red, calcium salt, lake red D, brilliant carmine 6B, eosin lake, rhodamine lake. B, Alizarin Lake, Brilliant Carmine 3B and the like.

The purple pigment includes manganese purple, fast violet B, methyl violet lake and the like. Examples of blue pigments include navy blue, cobalt blue, alkali blue lake, Victoria blue lake, phthalocyanine blue, metal-free phthalocyanine blue, partially chlorinated phthalocyanine blue, fast sky blue, and indaslen blue BC.

Examples of the green pigment include chrome green, chromium oxide, pigment green B, micalite green lake, and final yellow green G. As white pigments, zinc white, titanium oxide, antimony white,
And zinc sulfide.

The extender includes baryte powder, barium carbonate, clay, silica, white carbon, talc, alumina white and the like.

Of these colorant pigments, preferred are benzidine yellow G, benzidine yellow GR,
Brilliant carmine 6B, quinacridone, rhodamine lake B, phthalocyanine blue, metal-free phthalocyanine blue, and partially chlorinated phthalocyanine blue. These pigments may be used alone or in combination of two or more.

When a coloring material pigment is added according to the method of the present invention, it becomes ubiquitous in the shell material of the toner surface layer, so that the transparency of the fixed toner, that is, the transmission when the toner is developed and fixed on an OHP film in particular. And color reproducibility when colors are superimposed on a full-color image. Further, since the method is not a method of mechanically attaching the toner on the toner surface, it is possible to provide a developer free from in-machine contamination.

The dispersion concentration of the colorant pigment is usually 3 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the outer shell resin. If the amount is less than 3 parts by weight, the coloring power is weak and the tint becomes thin. If the amount is more than 50 parts by weight, the coloring power is too strong, so that the halftone reproducibility and the density gradation property in the printed image are poor. The image becomes a standing image and the image quality deteriorates.

Examples of the magnetic powder that can be used in the present invention include ferromagnetic metals and alloys such as ferrite and magnetite, cobalt, nickel and the like, compounds containing these elements, and ferromagnetic elements. Alloys that do not have a suitable heat treatment but become ferromagnetic, such as alloys of the type called Heusler alloys containing manganese and copper, such as manganese-copper-aluminum, manganese-copper-tin, or chromium dioxide , And others. These magnetic materials have an average particle size of 0.1
It is dispersed in the shell resin in the form of a fine powder of .about.1 .mu.m. Of these, ferrite and magnetite are preferred.

When magnetic fine powder is contained in order to obtain a magnetic toner, the treatment may be carried out in the same manner as in the case of the colorant. When the magnetic fine powder is used together with a so-called coupling agent such as a titanium coupling agent, a silane coupling agent or lecithin or after being treated with the coupling agent, the magnetic fine powder can be uniformly dispersed.

By adding the magnetic powder according to the method of the present invention,
Since it becomes ubiquitous in the shell material of the toner surface layer, it becomes possible to increase the magnetic force of the toner with a small amount of magnetic powder, and particularly in a two-component developing system, it effectively acts to prevent toner scattering.

The dispersion concentration of the magnetic powder is usually from 5 to 100 parts by weight, preferably from 10 to 70 parts by weight, of the coloring material pigment per 100 parts by weight of the outer shell resin. When the amount is less than 5 parts by weight, the magnetic force is weak, and there is no effect of addition.

The resin constituting the outer shell of the capsule toner of the present invention is not particularly limited as long as it has higher hydrophilicity than the thermoplastic resin used for the core material in the case of in situ polymerization. For example, a polymer of a nitrogen-containing monomer such as polyester, polyesteramide, polyamide, polyurea, or dimethylaminoethyl methacrylate / diethylaminoethyl methacrylate or a copolymer thereof with styrene or an unsaturated carboxylic acid ester, or acrylic A polymer of an unsaturated carboxylic acid such as an acid or methacrylic acid / an unsaturated dibasic acid / an unsaturated dibasic acid anhydride or a copolymer of the polymer with a styrene monomer is used. Above all, when amorphous polyester is used as the main component of the outer shell, it can be suitably used in the present invention because the obtained toner has excellent low-temperature fixability.

Such an amorphous polyester is usually
As constituent monomers, one or more dihydric alcohol monomers and one or more dihydric carboxylic acid monomers, further at least a trihydric or higher polyhydric alcohol monomer and / or a trivalent or higher polyhydric carboxylic acid Those obtained by condensation polymerization using an acid monomer are used. Such an amorphous polyester is usually 50 to 100% by weight based on the total weight of the resin in the outer shell.
Polyamide, polyesteramide, polyurea, or the like may be used as the other resin component contained in the outer shell in an amount of 0 to 50% by weight.

Examples of the dihydric alcohol monomer include polyoxypropylene (2.2) -2,2-bis (4-hydroxyphenyl) propane and polyoxypropylene (3.3)
-2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (2.0)-
Polyoxyethylene (2.0) -2,2-bis (4-hydroxyphenyl) propane, polyoxypropylene (6) -2,
Alkylene oxide adducts of bisphenol A such as 2-bis (4-hydroxyphenyl) propane, ethylene glycol, diethylene glycol, triethylene glycol, 1,2-propylene glycol, 1,3-propylene glycol, 1,4-butanediol, Neopentyl glycol, 1,4-butenediol, 1,5-pentanediol, 1,6-hexanediol, 1,4-cyclohexanedimethanol, dipropylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, bisphenol A , Bisphenol A
Propylene adduct, bisphenol A ethylene adduct, hydrogenated bisphenol A, and the like.

Examples of the trihydric or higher polyhydric alcohol monomer include sorbitol, 1,2,3,6-hexanetetrol, 1,4-sorbitan, pentaerythritol, dipentaerythritol, tripentaerythritol, 2,4
-Butanetriol, 1,2,5-pentanetriol, glycerol, 2-methylpropanetriol, 2-methyl-1,2,4-butanetriol, trimethylolethane, trimethylolpropane, 1,3,5-trihydroxy Methylbenzene and the like can be mentioned. Preferably, a trihydric alcohol is used. In the present invention, these two
A single or a plurality of monomers can be used from a monohydric alcohol monomer and a trihydric or higher polyhydric alcohol monomer.

As the acid component, divalent carboxylic acid monomers such as maleic acid, fumaric acid, citraconic acid, itaconic acid, glutaconic acid, phthalic acid, isophthalic acid, terephthalic acid, succinic acid and adipic acid , Sebacic acid, azelaic acid, malonic acid, n-dodecenylsuccinic acid, n-dodecylsuccinic acid, n-octylsuccinic acid, isooctenylsuccinic acid, isooctylsuccinic acid, and anhydrides or lower alkyl esters of these acids. No.

Examples of the trivalent or higher polyvalent carboxylic acid monomer include 1,2,4-benzenetricarboxylic acid and 2,5,7-
Naphthalenetricarboxylic acid, 1,2,4-naphthalenetricarboxylic acid, 1,2,4-butanetricarboxylic acid, 1,2,5-hexanetricarboxylic acid, 1,3-dicarboxyl-2-methyl-2-methylenecarboxypropane , 1,2,4-cyclohexanetricarboxylic acid, tetra (methylenecarboxyl) methane, 1,2,7,8-octanetetracarboxylic acid,
Examples thereof include pyromellitic acid, empole trimer acid, and acid anhydrides and lower alkyl esters thereof. Preferably, a trivalent carboxylic acid or a derivative thereof is used. In the present invention, these divalent carboxylic acid monomers and trivalent or higher polyvalent carboxylic acid monomers can be used alone or in combination of a plurality of monomers.

The method for producing the amorphous polyester in the present invention is not particularly limited, and it can be produced by esterification and transesterification using the above-mentioned monomers. Here, the term “amorphous” does not have a definite melting point, and if crystalline polyester is used in the present invention, the amount of energy required for melting is large, and the toner fixing property cannot be improved, which is not preferable.

The thus obtained amorphous polyester preferably has a glass transition point of 50 to 80 ° C. When the temperature is lower than 50 ° C., the storage stability of the toner deteriorates, and when the temperature exceeds 80 ° C., the fixing property of the toner deteriorates.
In the present invention, the glass transition point is defined by a differential scanning calorimeter (manufactured by Seiko Denshi Kogyo Co., Ltd.) at a heating rate of 10 ° C./min.
Means the temperature at the intersection of the extension of the baseline below the glass transition point and the tangent that shows the maximum slope from the peak rise to the peak apex.

The acid value of the amorphous polyester is 3
５０50 (KOHmg / g), more preferably 10-30 (KOHmg / g). 3
(KOH mg / g), it is difficult for the amorphous polyester as a shell material to appear at the interface during in situ polymerization, the storage stability of the toner is poor, and 50 (KOH mg / g).
If the amount exceeds g), the polyester easily migrates to the aqueous phase, and the production stability deteriorates. Here, the method for measuring the acid value is based on JIS
It is based on K0070.

The resin used as the main component of the hot-melt core material of the capsule toner of the present invention includes polyester resin, polyester / polyamide resin, polyamide resin,
Thermoplastic resins such as vinyl resins are mentioned, preferably,
Vinyl resin. The glass transition point derived from the thermoplastic resin as the main component of such a heat-meltable core material is 1
The temperature is preferably 0 to 50 ° C., but the glass transition point is 1
If the temperature is lower than 0 ° C., the storage stability of the capsule toner deteriorates, and
If the temperature exceeds 0 ° C., the fixing strength of the capsule toner deteriorates, which is not preferable.

Among the above thermoplastic resins, examples of the monomer constituting the vinyl resin include styrene, o-methylstyrene, m-methylstyrene, p-methylstyrene, α-methylstyrene, and p-ethylstyrene. , 2,4 −
Styrene or styrene derivatives such as dimethylstyrene, p-chlorostyrene, and vinylnaphthalene, for example, ethylenically unsaturated monoolefins such as ethylene, propylene, butylene, and isobutylene; for example, vinyl chloride;
Vinyl esters such as vinyl bromide, vinyl fluoride, vinyl acetate, vinyl propionate, vinyl formate, vinyl caproate, etc., for example, acrylic acid, methyl acrylate, ethyl acrylate, n-propyl acrylate, isopropyl acrylate, N-butyl acrylate, isobutyl acrylate, t-butyl acrylate, amyl acrylate, cyclohexyl acrylate, n-octyl acrylate, isooctyl acrylate, decyl acrylate, lauryl acrylate, 2-ethylhexyl acrylate, acrylic acid Stearyl, methoxyethyl acrylate, 2-acrylate
Hydroxyethyl, glycidyl acrylate, 2-chloroethyl acrylate, phenyl acrylate, α-methyl acrylate, methacrylic acid, methyl methacrylate,
Ethyl methacrylate, n-propyl methacrylate, isopropyl methacrylate, n-butyl methacrylate, isobutyl methacrylate, t-butyl methacrylate, amyl methacrylate, cyclohexyl methacrylate, n-octyl methacrylate, isooctyl methacrylate, methacrylic acid Decyl, lauryl methacrylate, methacrylic acid 2
-Ethylhexyl, stearyl methacrylate, methoxyethyl methacrylate, 2-hydroxyethyl methacrylate, glycidyl methacrylate, phenyl methacrylate,
Ethylenic monocarboxylic acids such as dimethylaminoethyl methacrylate, diethylaminoethyl methacrylate and the like, and esters thereof, for example, ethylenic monocarboxylic acid substitution products such as acrylonitrile, methacrylonitrile, and acrylamide; and ethylenic acid such as dimethyl maleate Dicarboxylic acids and substituted products thereof, for example, vinyl ketones such as vinyl methyl ketone; vinyl ethers such as vinyl methyl ether; vinylidene halides such as vinylidene chloride;
N-vinyl compounds such as vinylpyrrole, N-vinylpyrrolidone and the like can be mentioned.

Of the components constituting the resin for the core material according to the present invention, 50 to 90% by weight of styrene or a styrene derivative is used to form the main skeleton of the resin, and ethylenic is used to adjust the thermal characteristics such as the softening temperature of the resin. It is preferable to use 10 to 50% by weight of a monocarboxylic acid or an ester thereof because the glass transition point of the resin for the core material is easily controlled.

When a crosslinking agent is added to the monomer composition constituting the resin for the core material according to the present invention, for example, divinylbenzene, divinylnaphthalene, polyethylene glycol dimethacrylate, diethylene glycol diacrylate, triethylene glycol diacrylate may be used. Acrylate, 1,3-
Butylene glycol dimethacrylate, 1,6-hexylene glycol dimethacrylate, neopentyl glycol dimethacrylate, dipropylene glycol dimethacrylate, polypropylene glycol dimethacrylate, 2,2′-bis (4-methacryloxydiethoxyphenyl) propane, 2 General crosslinking such as 2,2'-bis (4-acryloxydiethoxyphenyl) propane, trimethylolpropane trimethacrylate, trimethylolpropane triacrylate, tetramethylolmethanetetraacrylate, dibromoneopentylglycol dimethacrylate, diallyl phthalate Add the agent appropriately (2 if necessary
(In combination of more than one).

The use amount of these crosslinking agents is 0.001 to 15% by weight, preferably 0.1 to 10% by weight, based on the polymerizable monomer. The amount of these crosslinking agents used is 15
If the amount is more than about 10% by weight, the toner is less likely to be melted by heat, resulting in poor heat fixing property or heat pressure fixing property. In addition,
If the content is less than 0.001% by weight, it is difficult to prevent the offset phenomenon in which a part of the toner does not completely adhere to the paper but adheres to the roller surface and is transferred to the next paper in the thermal pressure fixing. Further, the above monomer may be polymerized in the presence of an unsaturated polyester to form a graft or crosslinked polymer, which may be used as a resin for a core material.

Further, as a polymerization initiator used for producing a thermoplastic resin for a core material, 2,2′-azobis (2,4
-Dimethylvaleronitrile), 2,2'-azobisisobutyronitrile, 1,1'-azobis (cyclohexane-1-carbonitrile), 2,2'-azobis-4-methoxy-2,4
-Dimethylvaleronitrile, other azo or diazo polymerization initiators: benzoyl peroxide, methyl ethyl ketone peroxide, isopropyl peroxycarbonate, cumene hydroperoxide, 2,4-dichlorobenzoyl peroxide, lauroyl peroxide, dicumylper A peroxide-based polymerization initiator such as an oxide may be used.

For the purpose of adjusting the molecular weight and molecular weight distribution of the polymer, or the purpose of adjusting the reaction time, two or more polymerization initiators can be used in combination. The amount of the polymerization initiator to be used is 0.1 to 20 parts by weight, preferably 1 to 10 parts by weight, based on 100 parts by weight of the polymerization monomer.

Next, the method for producing the capsule toner for heat and pressure fixing of the present invention will be described in detail. The capsule toner of the present invention can be suitably produced by an in situ polymerization method from the viewpoint of simplifying production facilities and production steps. A method for producing a hot-press fixing capsule toner according to the present invention is directed to a hot-press fixing capsule comprising a hot-melt core material containing at least a thermoplastic resin and an outer shell provided so as to cover the surface of the core material. In the method for producing a toner, by performing in situ polymerization using an outer shell resin in which the above-described various additives are dispersed in advance, the surface of a core material is coated with the resin to form an outer shell in which the additives are dispersed. It is characterized by doing.

In this manufacturing method, the outer shell is formed by utilizing the property that a mixture of the core material and the outer shell material is dispersed in a dispersion medium and the outer shell material is unevenly distributed on the surface of the droplet. Can be done. That is, separation of the core constituent material and the outer shell constituent material occurs in the droplet of the mixed liquid due to the difference in the solubility index, and in this state, the polymerization of the core constituent material proceeds to form the core material resin, and The resin used as the shell constituent material becomes the outer shell as it is, and the capsule structure is formed. According to this method, since the outer shell is formed as a layer having a substantially uniform thickness, the toner has a feature that the charging characteristics of the toner become uniform.

In general, encapsulation by in-situ polymerization is performed by supplying a monomer, an initiator, and the like of a resin serving as an outer shell from one of an inner phase and an outer phase of a dispersed phase, and forming an outer shell by polymerization. This is performed by obtaining an encapsulated product ("Microcapsule" Sankyo Publishing Co., Ltd. 1987)
Year, Tamotsu Kondo, Naozumi Koishi). On the other hand, in the present invention,
Situ polymerization is different from encapsulation by general in situ polymerization, since the monomer of the core resin, the initiator, etc. are polymerized to form the core resin inside the outer shell resin. Since both are common in that monomers and the like are supplied only from the internal phase of the dispersed phase, the method of the present invention is also included in the in-situ polymerization in a broad sense.

In the present invention, in such an in situ polymerization method, an outer shell in which various additives are dispersed can be formed by previously dispersing various additives in the outer shell resin. According to this method, various additives are dispersed in the outer shell components and do not exist on the outer shell surface of the toner. No problem. In addition, as described above, the functions of various additives can be suitably exhibited.

The method of dispersing the additive in the outer shell resin is as follows.
A generally known method is used. For example, in addition to melt kneading and dispersion using a twin-screw kneader, a Banbury mixer, a kneader, or the like, melt blending and dispersion may be performed at the time of production of an outer shell resin.

In the present invention, when dispersing the mixture of the core material and the outer shell material in the dispersion medium, a dispersion stabilizer is contained in the dispersion medium in order to prevent aggregation and coalescence of the dispersoid. Keep it. Examples of the dispersion medium include water, methanol, ethanol, propanol, butanol, ethylene glycol, glycerin, acetonitrile, acetone, isopropyl ether, tetrahydrofuran, dioxane and the like. These can be used alone or in combination.

Examples of the dispersion stabilizer include gelatin, gelatin derivatives, polyvinyl alcohol, polystyrene sulfonic acid, hydroxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, sodium carboxymethyl cellulose, sodium polyacrylate, sodium dodecylbenzenesulfonate, sodium tetradecyl sulfate. , Sodium pentadecyl sulfate, sodium octyl sulfate, sodium allyl-alkyl-polyethersulfonate, sodium oleate, sodium laurate, sodium caprate, sodium caprylate, sodium caproate, potassium stearate, calcium oleate, 3,3 -Disulfonediphenylurea-4,4-diazo-bis-amino-β-
Sodium naphthol-6-sulfonate, ortho-carboxybenzene-azo-dimethylaniline, 2,2,5,5-
Use sodium tetramethyl-triphenylmethane-4,4-diazo-bis-β-naphthol-disulfonate, colloidal silica, alumina, tricalcium phosphate, ferric hydroxide, titanium hydroxide, aluminum hydroxide, etc. can do. Two or more of these dispersion stabilizers may be used in combination.

In the production method of the present invention, the amount of the amorphous polyester is usually 3 to 50 parts by weight, preferably 5 to 40 parts by weight, based on 100 parts by weight of the core material. If it is less than 3 parts by weight, the thickness of the outer shell becomes too thin and storage stability deteriorates. If it exceeds 50 parts by weight, the viscosity becomes high and atomization becomes difficult, resulting in poor production stability.

In the present invention, a capsule toner for heat and pressure fixing obtained by further performing seed polymerization using the capsule toner obtained as described above as precursor particles may be used. Therefore, in the present invention, the capsule toner includes those obtained by combining in situ polymerization and seed polymerization in addition to those obtained by the in situ polymerization method alone as described above.

That is, in the seed polymerization, at least a vinyl polymerizable monomer and a vinyl polymerization initiator are added to an aqueous suspension of the capsule toner (hereinafter sometimes referred to as precursor particles) obtained as described above. After being absorbed in the precursor particles, the monomer component in the precursor particles is polymerized. For example, immediately after the production of the precursor particles by the in situ polymerization method, at least a vinyl polymerizable monomer and a vinyl polymerization initiator are added in a suspended state to be absorbed in the precursor particles, Seee monomer component in particles
d may be polymerized. By doing so, the manufacturing process can be further simplified. The vinyl polymerizable monomer or the like to be absorbed in the precursor particles may be added in advance as a water emulsion.

The water emulsion to be added is obtained by emulsifying and dispersing a vinyl polymerizable monomer and a vinyl polymerization initiator in water together with a dispersion stabilizer, and further includes a crosslinking agent, an offset preventing agent, a charge controlling agent and the like. Can also be contained.

The vinyl polymerizable monomer used in the seed polymerization may be the same as that used in producing the precursor particles. Further, the same vinyl polymerization initiator, crosslinking agent and dispersion stabilizer as those used in the production of the above-mentioned precursor particles can be used. seed
The amount of the crosslinking agent used in the polymerization is 0.001 to 15% by weight, preferably 0.1 to 15% by weight, based on the vinyl polymerizable monomer.
Good to use at 10% by weight. When the use amount of these crosslinking agents is more than 15% by weight, the obtained toner is less likely to be melted by heat, and the heat fixing property or the heat pressure fixing property is inferior.
If the amount is less than 0.001% by weight, it is difficult to prevent the offset phenomenon in which a part of the toner does not completely adhere to the paper but adheres to the roller surface and is transferred to the next paper in the heat and pressure fixing.

In order to further improve the storage stability of the toner, a hydrophilic outer shell material such as the above-mentioned amorphous polyester may be added to the water emulsion. The amount added at that time is usually 1 to 20 parts by weight, preferably 3 to 15 parts by weight, based on 100 parts by weight of the core material. At this time, in the present invention,
In the outer shell resin to be added, the above-mentioned various additives may be dispersed in advance, in which case, similarly, selected from the group consisting of a conductive substance, a charge control agent, a wax component, a coloring material pigment, and a magnetic powder. One or more additives are used.

Further, in addition to the amorphous polyester as the hydrophilic outer shell material, for example, a vinyl resin having a hydrophilic group functional group such as a carboxyl group, an acid anhydride group, a hydroxyl group, an amino group, an ammonium ion, etc., and an amorphous polyester An amide, an amorphous polyamide, an epoxy resin or the like can be used in combination.
Such an aqueous emulsion can be prepared by uniformly dispersing it using an ultrasonic oscillator or the like.

The acid value of the amorphous polyester used in the seed polymerization is 3 to 50 as in the case of the first-stage reaction.
(KOH mg / g), more preferably 10 to 30 (KOH mg / g). 3 (KOH
mg / g), it becomes difficult for the amorphous polyester as a shell material to come out to the interface during seed polymerization, and the storage stability of the obtained toner is poor. If it exceeds 50 (KOHmg / g), the polyester becomes water-soluble. It is easy to transfer to the phase, and the production stability deteriorates. Here, the acid value is measured according to JIS K007.
0.

The amount of the water emulsion added is such that the amount of the vinyl polymerizable monomer used is 10 to 20 parts by weight based on 100 parts by weight of the precursor particles.
Adjust to be 0 parts by weight. If the amount is less than 10 parts by weight, there is no effect in improving the fixing property, and if it exceeds 200 parts by weight, it becomes difficult to uniformly absorb the monomer into the precursor particles.

By the addition of the water emulsion, the vinyl polymerizable monomer is absorbed into the precursor particles and the precursor particles swell. Then, in this state, the monomer components in the precursor particles polymerize. That is, seed polymerization using precursor particles as seed particles.

When the seed polymerization is further carried out in this manner, the following points are further improved as compared with the capsule toner produced by the in situ polymerization method alone. That is, the encapsulated toner produced by the in situ polymerization method is superior to the conventional one in terms of low-temperature fixability and storage stability, but by further performing the seed polymerization method, a more uniform outer shell is formed from an interface science perspective. , And further excellent storage stability. Further, since the polymerizable monomer of the core material can be polymerized in two stages (in situ polymerization reaction and seed polymerization reaction), the thermoplasticity in the core material can be further improved by appropriately using a crosslinking agent. The control of the molecular weight of the resin is facilitated, and the low-temperature fixability and the offset resistance can be further improved. In particular, it is possible to provide a toner suitable not only for fixing at high speed but also for fixing at low speed.

The particle size of the capsule toner in the present invention is not particularly limited, but the average particle size is usually 3 to 30 μm. The outer shell of the capsule toner has a thickness of 0.
It is preferably from 01 to 1 μm, and if it is less than 0.01 μm, the blocking resistance deteriorates, and if it exceeds 1 μm, the heat melting property deteriorates, which is not preferable.

In the capsule toner of the present invention, if necessary, a fluidity improver, a cleaning improver, and the like can be used. Examples of the fluidity improver include silica, alumina, titanium oxide, barium titanate, magnesium titanate, calcium titanate, strontium titanate, zinc oxide, silica sand, clay, mica, wollastonite, diatomaceous earth, and chromium oxide. , Cerium oxide, red iron oxide, antimony trioxide, magnesium oxide, zirconium oxide, barium sulfate, barium carbonate, calcium carbonate, silicon carbide, silicon nitride and the like. Particularly, fine powder of silica is preferable.

The fine silica powder is Si—O—Si
It is a fine powder having a bond, and may be any of those manufactured by a dry method and a wet method. In addition to anhydrous silicon dioxide, aluminum silicate, sodium silicate,
Any of potassium silicate, magnesium silicate, zinc silicate and the like may be used, but those containing 85% by weight or more of SiO ₂ are preferable. Further, fine powder of silica surface-treated with a silane coupling agent, a titanium coupling agent, silicon oil, silicon oil having an amine in a side chain, or the like can be used.

Examples of the cleaning property improver include metal salts of higher fatty acids typified by zinc stearate, and fine powder of fluorine-containing high molecular weight. Further additives for adjusting the developability, for example, methyl methacrylate,
Fine particle powder of a polymer such as butyl methacrylate may be used. Further, a small amount of carbon black may be used for toning and resistance adjustment. Conventionally known carbon blacks such as furnace black, channel black, and acetylene black can be used.

The capsule toner for heat and pressure fixing according to the present invention comprises:
When it contains a magnetic fine powder, it is used alone as a developer. When it does not contain a magnetic fine powder, it is mixed with a non-magnetic one-component developer or a carrier to form a two-component developer. Can be prepared and used. The carrier is not particularly limited, but includes iron powder,
Ferrite, glass beads or the like, or a resin-coated material thereof, a magnetite fine powder, a resin carrier in which ferrite fine powder is kneaded in a resin, or the like is used. The mixing ratio of the toner to the carrier is 0.5 to 20% by weight. The carrier has a particle size of 15 to 500 μm.

The capsule toner for heat and pressure fixing of the present invention gives good fixing strength by fixing to a recording material such as paper by using both heat and pressure.
If heat and pressure are used in combination, a known heat roller fixing method, or a method in which an unfixed toner image on a recording material is heated by a heating unit and a heat-resistant sheet as described in, for example, JP-A-2-190870. Means, by heating and melting through the heat-resistant sheet, and fixing, or, for example, as described in JP-A-2-162356, a fixedly supported heating element, and pressure-contacted to the heating element, and a film A method such as a method in which a visible image of the toner is heated and pressed and fixed on the recording material by a pressure member for bringing the recording material into close contact with the heating element via the fixing member is suitable for fixing the capsule toner of the present invention.

[0092]

The present invention will be described in more detail with reference to the following Examples, Comparative Examples and Test Examples, but the present invention is not limited to these Examples and the like.

Resin Production Example 1 Propylene oxide adduct of bisphenol A 36
7.5 g, 146.4 g of an ethylene oxide adduct of bisphenol A, 126.0 g of terephthalic acid, 40.2 g of dodecenyl succinic anhydride, and 77.7 g of trimellitic anhydride.
7 g was placed in a glass two-liter four-necked flask, fitted with a thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube, and reacted at 220 ° C. under a nitrogen stream in a mantle heater. .

The degree of polymerization was monitored from the softening point in accordance with ASTM E28-67. When the softening point reached 110 ° C., the reaction was terminated. This resin is referred to as resin A. Resin A measured with a differential scanning calorimeter (manufactured by Seiko Instruments Inc.)
Was 65 ° C. Also, JIS
The acid value measured by a method according to K0070 is 18
(KOH mg / g).

Resin Production Example 2 Propylene oxide adduct of bisphenol A 51
4.5 g, 204.8 g of an ethylene oxide adduct of bisphenol A, 226.6 g of terephthalic acid, and 48.0 g of trimellitic anhydride are placed in a glass 2-liter four-necked flask, and a thermometer, a stainless steel stirring rod, and a flow-down. The reaction was carried out at 220 ° C. under a nitrogen stream in a heating mantle with a condenser and a nitrogen inlet tube.

The degree of polymerization was monitored from the softening point in accordance with ASTM E28-67. When the softening point reached 105 ° C., the reaction was completed. This resin is referred to as resin B. The value of the glass transition point of the resin B measured by a differential scanning calorimeter (manufactured by Seiko Instruments Inc.) was 63 ° C. Also JIS
The acid value measured by a method according to K0070 is 12
(KOH mg / g).

Resin Production Example 3 Propylene oxide adduct of bisphenol A 525
g, terephthalic acid 136.5 g, dodecenyl succinic anhydride 1
Put 60.8g into a 2 liter glass four-necked flask,
A thermometer, a stainless steel stirring rod, a falling condenser, and a nitrogen inlet tube were attached, and the reaction was carried out at 220 ° C. in a mantle heater under a nitrogen stream.

The degree of polymerization was monitored from the softening point in accordance with ASTM E28-67. When the softening point reached 110 ° C., the reaction was terminated. This resin is referred to as resin C. The value of the glass transition point of the resin C measured by a differential scanning calorimeter (manufactured by Seiko Instruments Inc.) was 63 ° C. Also JIS
The acid value measured by a method according to K0070 is 10
(KOH mg / g).

Example 1 100 parts by weight of resin A and carbon black "Monarch 88"
After thoroughly mixing 25 parts by weight of "0" (manufactured by Cabot Corporation) with a Henschel mixer, the mixture was kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled and then pulverized to obtain a kneaded material A. Here, the resistivity of the resin A and the kneaded material A is 5 × 10 ¹³ Ωc, respectively.
m, 2.2 × 10 ⁷ Ωcm.

The resistivity was measured according to the following procedure. First, as a sample, the crushed material was filled in a tableting machine, and a load of 10 tons was applied to produce a pellet having a thickness of about 2 mm and a diameter of 60φ. This was measured using an impedance analyzer HP4284A manufactured by Yokogawa-Hewlett-Packard Company, and the resistance component R measured by the AC bridge method was used as the resistivity.

69.0 parts by weight of styrene, 2- (acrylic acid)
31.0 parts by weight of ethylhexyl, divinylbenzene
To 1 part by weight, 20 parts by weight of the kneaded material A and 4.5 parts by weight of 2,2′-azobisisobutyronitrile were added, and the mixture was dispersed using a magnetic stirrer for 1 hour to obtain a polymerizable composition. Was. Next, 120 g of the above polymerizable composition was added to 280 g of an aqueous colloid solution of 4% by weight of tricalcium phosphate prepared in advance in a glass separable flask having a capacity of 1 liter, and TK homomixer (manufactured by Tokushu Kika Kogyo Co., Ltd.) ), And dispersed at 10,000 rpm for 3 minutes. This was covered with a four-neck glass lid, fitted with a reflux condenser, a thermometer, a nitrogen inlet tube, and a stainless steel stirrer, and placed in an electric heating mantle. This was heated to 80 ° C. while stirring under a nitrogen stream, and reacted for 8 hours.

After cooling, the dispersion medium was dissolved with a 10% hydrochloric acid aqueous solution, filtered, washed with water, dried under reduced pressure at 45 ° C. and 20 mmHg for 12 hours, and classified by an air classifier to give an average particle size of 8 μm.
Thus, a capsule toner in which the outer shell of m is an amorphous polyester was obtained. 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts by weight of this capsule toner and mixed to obtain an encapsulated toner according to the present invention. This is referred to as toner 1. The glass transition point derived from the resin in the core material was 34.5 ° C., and the softening point of Toner 1 was 128.3 ° C.

The obtained toner was uniformly dispersed in a vinyl acetate resin (manufactured by Konishi Co., Ltd., bond for woodworking) and allowed to stand at room temperature for one week. After vapor dyeing the toner-containing resin with an osmium aqueous solution, an ultramicrotome (LKB)
FIG. 1 shows a photograph (× 5000) obtained by observing this sample with a transmission electron microscope (JEM-2000FX, manufactured by JEOL Ltd.). . In the capsule toner obtained in the present invention, it was confirmed that the conductive substance was dispersed in the outer shell resin.

Example 2 100 parts by weight of resin B and carbon black "REGAL 99"
R "(manufactured by Cabot Corporation), 25 parts by weight, were thoroughly mixed with a Henschel mixer, kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled and pulverized to obtain a kneaded material B. Here, the resistivity of each of the resin B and the kneaded material B is 5 × 10 ¹³ Ωc.
m, 6.5 × 10 ⁸ Ωcm.

69.0 parts by weight of styrene, acrylic acid 2-
31.0 parts by weight of ethylhexyl, divinylbenzene
1 part by weight of carbon black GPT-5 as a colorant
10 parts by weight of 05P (manufactured by Ryoyu Kogyo Co., Ltd.), 15 parts by weight of kneaded material B, and 4.5 parts by weight of 2,2′-azobisisobutyronitrile were added, and the mixture was dispersed using a magnetic stirrer for 1 hour. Thus, a polymerizable composition was obtained. Next, 120 g of the above polymerizable composition was added to 280 g of an aqueous colloid solution of 4% by weight of tricalcium phosphate prepared in advance in a 1-liter glass separable flask, and the number of revolutions was 10,000 rpm using a TK homomixer. For 3 minutes. This was covered with a four-neck glass lid, a reflux condenser, a thermometer,
Attach a nitrogen introduction tube and a stainless steel stirring rod,
It was installed in an electric heating mantle. This was heated to 80 ° C. while stirring under a nitrogen stream, and reacted for 8 hours.

After cooling, the dispersion medium was dissolved in a 10% aqueous hydrochloric acid solution, filtered, washed with water, dried under reduced pressure at 45 ° C. and 20 mmHg for 12 hours, and classified with an air classifier to give an average particle size of 8 μm.
Thus, a capsule toner in which the outer shell of m is an amorphous polyester was obtained. 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added to 100 parts by weight of this capsule toner and mixed to obtain an encapsulated toner according to the present invention. This is referred to as toner 2. The glass transition point derived from the core material was 34.1 ° C., and the softening point of Toner 2 was 125.5 ° C.

Example 3 100 parts by weight of resin A and 20 parts by weight of conductive tin oxide "T-1" (manufactured by Mitsubishi Metals Corporation) were thoroughly mixed with a Henschel mixer, and kneaded with a twin-screw extruder equipped with a barrel cooling device. Then, the mixture was cooled and pulverized to obtain a kneaded material C. The resistivity of the obtained kneaded material C was 5.2 × 10 ⁹ Ωcm.

The procedure of Example 2 was repeated, except that the kneaded material B was changed to the kneaded material B, until the surface treatment was carried out to obtain a capsule toner. This is referred to as toner 3. The glass transition point derived from the core material was 35.1 ° C., and the softening point of Toner 3 was 127.5 ° C.

Comparative Example 1 In Example 1, except that kneaded material A was changed to resin A,
By the same operation as in Example 1, the process up to the surface treatment was performed to obtain a capsule toner. This is designated as comparative toner 1. The glass transition point derived from the resin in the core material is 34.5 ° C.,
The softening point of Comparative Toner 1 was 130.1 ° C.

Comparative Example 2 Capsule toner 10 obtained in the same manner as in Example 1 except that kneaded material A was changed to resin A.
0 parts by weight and 6 parts by weight of carbon black "Monarch 880" (manufactured by Cabot) were mixed well with a Henschel mixer. Next, carbon black was immobilized on the surface of the toner particles by hybridization. Thereafter, 100 parts by weight of the capsule toner was added to a hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.).
4 parts by weight were added and mixed. This is designated as comparative toner 2.

Example 4 Resin A (100 parts by weight) and negatively chargeable charge control agent "T-77"
After 10 parts by weight (manufactured by Hodogaya Chemical Industry Co., Ltd.) were mixed well with a Henschel mixer, the mixture was kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled, and pulverized to obtain a kneaded material D.

Grafted carbon black "GPE-3" was added to 69.0 parts by weight of styrene, 31.0 parts by weight of 2-ethylhexyl acrylate, and 6.0 parts by weight of 2,2'-azobisisobutyronitrile as a coloring agent. 20 parts by weight of the kneaded material D was added, and the mixture was dispersed with a magnetic stirrer for 1 hour to obtain a polymerizable composition. Next, 240 g of the above polymerizable composition was added to 560 g of an aqueous colloid solution of 4% by weight of tricalcium phosphate prepared in advance in a 2-liter glass separable flask, and emulsified and dispersed using a TK homomixer. .

Next, a four-neck glass lid was fitted, a reflux condenser, a thermometer, a nitrogen inlet tube, and a stainless steel stirring rod were attached, and the flask was set in an electric heating mantle heater. While continuing to stir under nitrogen, the temperature was raised to 85 ° C., and a polymerization reaction was performed for 10 hours to form seed particles, which were cooled to room temperature to obtain precursor particles.

Next, in the aqueous suspension of the precursor particles,
13.0 parts by weight of styrene, 7.0 parts by weight of 2-ethylhexyl acrylate, 2,2'-azobisisobutyronitrile 0 prepared by an ultrasonic oscillator (US-150, manufactured by Nippon Seiki Seisakusho) 4 parts by weight of a water emulsion consisting of 0.4 parts by weight, 0.22 parts by weight of divinylbenzene, 2.0 parts by weight of the kneaded material D, 0.1 parts by weight of sodium lauryl sulfate and 20 parts by weight of water were added dropwise. While continuing stirring under the temperature, the temperature was raised to 85 ° C. as a second stage polymerization, and the reaction was carried out for 10 hours. After cooling, the dispersion medium was dissolved in a 10% hydrochloric acid aqueous solution, filtered, washed with water, air-dried, and then dried at 45 ° C. for 12 hours.
It was dried under reduced pressure at 0 mmHg and classified by an air classifier to obtain a capsule toner having an average particle size of 8 μm and an outer shell made of amorphous polyester.

To 100 parts by weight of the encapsulated toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" was added and mixed to obtain an encapsulated toner of the present invention. This is referred to as toner 4. The glass transition point derived from the resin in the core material is 27.5 ° C., and the softening point of Toner 4 is 108.0 ° C.
Met.

Example 5 100 parts by weight of resin B and positively chargeable charge control agent "N-01"
10 parts by weight (manufactured by Orient Chemical Co., Ltd.) were mixed well with a Henschel mixer, kneaded with a twin-screw extruder equipped with a barrel cooling device, and cooled and pulverized to obtain a kneaded material E. Example 4
, A capsule toner was obtained by performing the same procedures as in Example 4 except that kneaded material D was changed to kneaded material E. This is referred to as toner 5. The glass transition point derived from the core material is 27.0 ° C., and the softening point of toner 5 is 10
7.0 ° C.

Example 6 100 parts by weight of resin C and negatively chargeable charge control agent "TRH"
After 10 parts by weight (manufactured by Hodogaya Chemical Co., Ltd.) were mixed well with a Henschel mixer, the mixture was kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled and pulverized to obtain a kneaded material F. Example 4 Example 4 was repeated except that the kneaded material D was changed to the kneaded material F.
By the same operation as described above, the surface treatment was performed to obtain a capsule toner. This is referred to as toner 6. The glass transition point derived from the core material is 28.0 ° C., and the softening point of toner 6 is 10
8.5 ° C.

Comparative Example 3 A surface was prepared in the same manner as in Comparative Example 2 except that carbon black was replaced by 5 parts by weight of a charge control agent “T-77” (manufactured by Hodogaya Chemical Industry Co., Ltd.). The process was repeated until a capsule toner was obtained. This is designated as comparative toner 3.

Example 7 100 parts by weight of resin A and 20 parts by weight of polyethylene wax “HI-WAX 200P” (manufactured by Mitsui Petrochemical Co.) were thoroughly mixed with a Henschel mixer, and kneaded with a twin-screw extruder equipped with a barrel cooling device. After cooling, the mixture was ground to obtain a kneaded material G.

A capsule toner was obtained in the same manner as in Example 2 except that kneaded material B was changed to kneaded material G in Example 2. This is referred to as toner 7. The glass transition point derived from the core material was 36.0 ° C., and the softening point of Toner 7 was 126.0 ° C.

Example 8 100 parts by weight of resin A and polypropylene wax "NP-
055 "(manufactured by Mitsui Petrochemical Co., Ltd.) was thoroughly mixed with a Henschel mixer, and then the mixture was equipped with a barrel cooling device.
The mixture was kneaded with a screw extruder, cooled and pulverized to obtain a kneaded material H. In Example 2, except that kneaded material B was changed to kneaded material H,
By performing the same operations as in Example 2, up to the surface treatment, a capsule toner was obtained. This is referred to as toner 8. The glass transition point derived from the core material was 36.5 ° C., and the softening point of Toner 8 was 128.0 ° C.

Comparative Example 4 The procedure of Comparative Example 2 was repeated, except that the carbon black was replaced by 10 parts by weight of polypropylene wax “NP-055” (manufactured by Mitsui Petrochemical Co., Ltd.). The process was performed to obtain a capsule toner. This is designated as comparative toner 4.

Example 9 100 parts by weight of resin B and magnetite “EPT-100”
After 25 parts by weight of "1" (manufactured by Toda Kogyo KK) were mixed well with a Henschel mixer, the mixture was kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled, and pulverized to obtain a kneaded material I. Example 2 Example 2 was repeated except that kneaded material B was changed to kneaded material I.
By the same operation as described above, the surface treatment was performed to obtain a capsule toner. This is referred to as toner 9. The glass transition point derived from the core material is 35.8 ° C., and the softening point of toner 9 is 12
7.0 ° C.

Comparative Example 5 A surface treatment was performed by the same operation as in Comparative Example 2, except that 10 parts by weight of magnetite “EPT-1001” (manufactured by Toda Kogyo Co., Ltd.) was used instead of carbon black. A capsule toner was obtained. This is designated as Comparative Toner 5.

Example 10 100 parts by weight of resin B and a yellow pigment "Seikafast Yellow"
After mixing 25 parts by weight of "2400" (manufactured by Dainichi Seika Kogyo Co., Ltd.) with a Henschel mixer, the mixture was kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled, and pulverized to obtain a kneaded material J.

69.0 parts by weight of styrene, acrylic acid 2-
31.0 parts by weight of ethylhexyl, divinylbenzene
To 1 part by weight, 15 parts by weight of the kneaded material J and 4.5 parts by weight of 2,2'-azobisisobutyronitrile were added, and the mixture was dispersed for 1 hour using a magnetic stirrer to obtain a polymerizable composition. Was. Next, 120 g of the above polymerizable composition was added to 280 g of an aqueous colloid solution of 4% by weight of tricalcium phosphate previously prepared in a glass separable flask having a capacity of 1 liter, and the number of revolutions was 10,000 using a TK homomixer.
Dispersed for 3 minutes at rpm. This was covered with a four-neck glass lid, fitted with a reflux condenser, a thermometer, a nitrogen inlet tube, and a stainless steel stirrer, and placed in an electric heating mantle. This was heated to 80 ° C. while stirring under a nitrogen stream, and reacted for 8 hours.

After cooling, the dispersion medium was dissolved with a 10% aqueous hydrochloric acid solution, filtered, washed with water, dried under reduced pressure at 45 ° C. and 20 mmHg for 12 hours, and classified with an air classifier to give an average particle size of 8 μm.
Thus, a capsule toner in which the outer shell of m is an amorphous polyester was obtained.

To 100 parts by weight of this capsule toner, 0.4 parts by weight of hydrophobic silica fine powder "Aerosil R-972" (manufactured by Nippon Aerosil Co., Ltd.) was added and mixed to obtain an encapsulated toner according to the present invention. This is referred to as toner 10. The glass transition point derived from the core material was 34.5 ° C., and the softening point of Toner 10 was 126.0 ° C.

Example 11 100 parts by weight of resin B and magenta pigment "Hostaperm Pink E
B "(manufactured by Hoechst) 25 parts by weight was mixed well with a Henschel mixer, kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled and then pulverized to obtain a kneaded material K.

[0130] In Example 10, the kneaded material J was replaced with the kneaded material K.
The same procedure as in Example 10 was carried out except that the surface treatment was performed to obtain a capsule toner. This is called toner 11
And The glass transition point derived from the core material is 35.0 ° C.,
The softening point of Toner 11 was 126.5 ° C.

Example 12 100 parts by weight of resin C and magenta pigment "Hostaperm Pink E
B "(manufactured by Hoechst), 25 parts by weight, were thoroughly mixed with a Henschel mixer, kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled and pulverized to obtain a kneaded material L.

In Example 10, the kneaded material J was replaced with the kneaded material L.
The same procedure as in Example 10 was carried out except that the surface treatment was performed to obtain a capsule toner. This is called toner 12
And The glass transition point derived from the core material is 34.3 ° C,
The softening point of Toner 12 was 125.8 ° C.

Example 13 100 parts by weight of Resin B and 25 parts by weight of a cyan pigment "KET Blue 104" (manufactured by Dainippon Ink and Chemicals, Inc.) were thoroughly mixed with a Henschel mixer, and then mixed with a twin-screw extruder equipped with a barrel cooling device. The mixture was kneaded, cooled and pulverized to obtain a kneaded material M.

In Example 10, the kneaded material J was replaced with the kneaded material M
The same procedure as in Example 10 was carried out except that the surface treatment was performed to obtain a capsule toner. This is called toner 13
And The glass transition point derived from the core material is 34.0 ° C,
The softening point of Toner 13 was 125.5 ° C.

Example 14 100 parts by weight of Resin C and 25 parts by weight of a cyan pigment "KET Blue 104" (manufactured by Dainippon Ink and Chemicals, Inc.) were thoroughly mixed with a Henschel mixer, and then mixed with a twin-screw extruder equipped with a barrel cooling device. The mixture was kneaded, cooled and pulverized to obtain a kneaded material N.

In Example 10, the kneaded material J was replaced with the kneaded material N.
The same procedure as in Example 10 was carried out except that the surface treatment was performed to obtain a capsule toner. This is called toner 14
And The glass transition point derived from the core material is 33.5 ° C,
The softening point of Toner 14 was 125.0 ° C.

Comparative Example 6 The procedure of Comparative Example 2 was repeated, except that the carbon black was replaced by 10 parts by weight of a yellow pigment “Seikafast Yellow 2400” (manufactured by Dainichi Seika Kogyo Co., Ltd.). The process was performed to obtain a capsule toner. This is designated as Comparative Toner 6.

Example 15 100 parts by weight of resin A and negative charge control agent "T-77"
10 parts by weight, polypropylene wax "NP-055"
After thoroughly mixing 20 parts by weight with a Henschel mixer, the mixture was kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled and pulverized to obtain a kneaded material O.

A capsule toner was obtained in the same manner as in Example 4 except that kneaded material D was changed to kneaded material O in Example 4. This is referred to as toner 15. The glass transition point derived from the core material was 28.0 ° C., and the softening point of Toner 15 was 109.0 ° C.

Example 16 100 parts by weight of resin A and positively chargeable charge control agent "N-01"
10 parts by weight and carbon black "Monarch 880" 25
After the weight parts were mixed well with a Henschel mixer, the mixture was kneaded with a twin-screw extruder equipped with a barrel cooling device, cooled and then pulverized to obtain a kneaded material P.

A capsule toner was obtained in the same manner as in Example 4 except that kneaded material D was changed to kneaded material P in Example 4. This is referred to as toner 16. The glass transition point derived from the core material was 27.7 ° C., and the softening point of Toner 16 was 108.8 ° C.

Test Example Each of the toners obtained in the above Examples and Comparative Examples was 6 parts by weight and styrene / particles having a particle size of 250 to 400 mesh.
Put 94 parts by weight of spherical ferrite powder coated with methyl methacrylate resin in a plastic container and rotate at 150 rpm.
For 20 minutes by rotating the entire container on a roller to prepare a developer. The obtained developer was evaluated for charge amount, fixing property, blocking resistance, cleaning property, and contamination in the machine.

(1) The charge amount was measured by a blow-off type charge amount measuring device described below. That is,
First, use a specific charge measuring device equipped with a Faraday gauge, a condenser, and an electrometer.
W (g) (0.15 to 0.20 g) of the prepared developer was placed in a brass measuring cell provided with a stainless steel mesh (which can be appropriately changed to a size that does not allow carrier particles to pass through). Next, after suctioning through the suction port for 5 seconds, the air pressure regulator is set to 0.6.
Blowing was performed for 5 seconds at a pressure indicating kgf / cm ² to remove only the toner from the cell.

At this time, the voltage of the electrometer 2 seconds after the start of blowing was set to V (volt). Here, assuming that the electric capacity of the capacitor is C (μF), the specific charge Q / m of the toner can be obtained by the following equation. Q / m (μC / g) = C × V / m Here, m is the weight of the toner contained in the developer in W (g), and the weight of the toner in the developer is represented by T (g). When the weight of the developer is D (g), the toner concentration of the sample is expressed as T / D × 100 (%), and m is obtained by the following equation. m (g) = W × (T / D) Tables 1 to 6 show the results of the measurement of the charge amount of the developer prepared under a normal environment.

[0145]

[Table 1]

[0146]

[Table 2]

[0147]

[Table 3]

[0148]

[Table 4]

[0149]

[Table 5]

[0150]

[Table 6]

(2) The fixability was evaluated by the method described below. That is, the above-mentioned prepared developer is used in a commercially available electrophotographic copying machine (rotational speeds of the photoconductor and the fixing roller are as shown in Tables 1 to 6, the heat pressure temperature in the fixing device is made variable, and the oil coating device is removed. Image was obtained using the above method. The fixing temperature was controlled at 100 ° C. to 240 ° C., and the fixing property and offset property of the image were evaluated. The results are also shown in Tables 1 to 6.

Here, the minimum fixing temperature is 15 m
A 500 g load is placed on a sand eraser mx 7.5 mm,
The image fixed through the fixing device was rubbed 5 times back and forth, and before and after the rubbing, the optical reflection density was measured with a Macbeth reflection densitometer, and the temperature of the fixing roller when the fixing rate exceeded 70% as defined below. Say. Fixing rate = (image density after rubbing / image density before rubbing) ×
100

(3) Regarding the blocking resistance, the degree of agglomeration when each toner was allowed to stand at 50 ° C. and a relative humidity of 40% for 24 hours was evaluated. The results are also shown in Tables 1 to 6.

(4) Further, using the above-mentioned electrophotographic copying machine (the photosensitive member is cleaned by a blade cleaning method), 10,000 continuous copies are made, and black streaks resulting from poor cleaning appear on paper as a transfer material. I checked the number of sheets to be played. In addition, the number of sheets in which in-machine contamination occurs was similarly examined. The results are also shown in Tables 1 to 6.

As is clear from Tables 1 to 6, all of the toners 1 to 16 of the present invention exhibited excellent effects due to the various additives described in Tables 1 to 6, and the occurrence of in-machine contamination and the like was also observed. There was no occurrence, and the low-temperature fixability and blocking resistance were also good. On the other hand, in the comparative toner 1 containing no conductive substance, black streaks due to poor cleaning occurred and the image quality was deteriorated. Further, in comparative toners 2, 3, 5, and 6 in which a conductive material, a charge control agent, a magnetic powder, and a coloring material pigment were adhered on the surface of the toner, in-machine contamination due to additives such as a conductive material occurred. Further, in the comparative toner 4 in which the wax component was adhered on the surface of the toner, the photoconductor was contaminated by the wax component.

[0156]

According to the capsule toner for heat and pressure fixing obtained in the present invention, various additives are dispersed in the outer shell resin and do not exist on the outer shell surface of the toner. Thus, there is no problem that various additives are peeled off and contamination in the machine is caused. In addition, the functions of various additives can be suitably exhibited. Furthermore, in the heat and pressure fixing method such as a heat roller, the offset resistance is excellent, the fixing can be performed at a low fixing temperature, the blocking resistance is excellent, and a clear image without fog can be stably formed many times. .

[Brief description of the drawings]

FIG. 1 is a photograph showing a particle structure of a toner obtained by observing a cross section of a capsule toner for heat and pressure fixing of the present invention obtained in Example 1 using a transmission electron microscope.

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-2-116856 (JP, A) JP-A-3-155560 (JP, A) JP-A-3-296069 (JP, A) JP-A-1- 193746 (JP, A) JP-A-63-89867 (JP, A) JP-A-63-179366 (JP, A) JP-A-59-170851 (JP, A) JP-A-5-197190 (JP, A) (58) Field surveyed (Int. Cl. ⁷ , DB name) G03G 9/08 311

Claims (4)

(57) [Claims] 1. A method for producing a capsule toner for heat and pressure fixing comprising a heat-fusible core material containing at least a thermoplastic resin and an outer shell provided so as to cover the surface of the core material, , Charge control agent, wax component,
By performing in situ polymerization using a resin in which one or more additives selected from the group consisting of colorant pigments and magnetic powders are dispersed in advance, the surface of the core material is coated with the resin and the additives are dispersed. A method for producing a capsule toner for heat and pressure fixing, characterized in that a formed outer shell is formed. 2. The method according to claim 1, wherein the main component of the resin constituting the outer shell is an amorphous polyester. 3. An amorphous polyester comprising, as constituent monomers, at least one dihydric alcohol monomer and at least one divalent carboxylic acid monomer, and at least a trihydric or higher polyhydric alcohol monomer. Obtained by polycondensation using an isomer and / or a trivalent or higher polycarboxylic acid monomer, and having a glass transition point of 50 to 80 ° C and an acid value of 3 to 50 (KO
Hmg / g). 4. A capsule toner for heat and pressure fixing, obtainable by the production method according to claim 1. "